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  • 1990-1994  (1,697)
  • 1992  (1,697)
  • Cell & Developmental Biology  (1,697)
  • Nuclear reactions
  • 101
    Electronic Resource
    Electronic Resource
    The cell biology of blastocyst development (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 492-504 
    Details
    ISSN: 1040-452X
    Keywords: Preimplantation development ; Compaction ; Cavitation ; Blastocyst ; Na/K-ATPase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Preimplantation development encompasses the “free”-living period of mammalian embryo-genesis, which culminates in the formation of a fluid-filled structure, the blastocyst. Cavitation (blastocyst formation) is accompanied by the expression of a novel set of gene products that contribute directly to the attainment of cell polarity with the trophectoderm, which is both the first epithelium of development and the outer cell layer encircling the inner cell mass of the blastocyst. Several of these gene products have been identified and include the tight junction (ZO-1), Na/K-ATPase (α and β subunits), uvomorulin, gap junction (connexin43), and growth factors such as transforming growth factor-α (TGF-α) and epidermal growth factor (EGF). This review will examine the role(s) of each of these gene products during the onset and progression of blastocyst formation. The trophectodermal tight junctional permeability seal regulates the leakage of blastocoel fluid and also assists in the maintenance of a polarized Na/K-ATPase distribution to the basolateral plasma membrane domain of the mural trophectoderm. The polarized distribution of the Na/K-ATPase plays an integral role in the establishment of a trans-trophectoderm Na+ gradient, which drives the osmotic accumulation of water across the epithelium into the nascent blastocoelic cavity. The cell adhesion provided by uvomorulin is necessary for the establishment of the tight junctional seal, as well as the maintenance of the polarized Na/K-ATPase distribution. Growth factors such as TGF-α and EGF stimulate an increase in the rate of blastocoel expansion, which could, in part, be mediated by secondary messengers that result in an increase in Na/K-ATPase activity. Insight into the mechanism of cavitation has, therefore, directly linked blastocyst formation to trophectoderm cell differentiation, which arises through fundamental cell biological processes that are directly involved in the attainment of epithelial cell polarity. © 1992 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330417
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  • 102
    Electronic Resource
    Electronic Resource
    The main adenosine triphosphate-binding component of amphibian oocytes is ferritin (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 48-54 
    Details
    ISSN: 1040-452X
    Keywords: Ferritin Nucleotide-binding ; ATP ; GTP ; Amphibian oocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: After fractionation of mitochondrion-free extracts of Xenopus laevis and Rana temporaria oocytes in sucrose gradients, a distinct peak of adenosine triphosphate (ATP)/guanosine triphosphate (GTP)-binding activity in the 50-70 S range has been detected. This substance has a boyant density in Cs2SO4 of 1.45 g/cm3. The nucleotide-binding substance has been purified to apparent homogenety. By means of electron microscopy, sodium dodecyl sulfate-electrophoresis and other methods it has been identified as ferritin.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310109
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  • 103
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992) 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310101
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  • 104
    Electronic Resource
    Electronic Resource
    Expression and regulation of casein kinase 2 during heat shock in Verticillium dahliae (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 42-47 
    Details
    ISSN: 1040-452X
    Keywords: Casein kinase II ; Heat shock ; Posttranslational regulation ; Protein synthesis ; Cotton parasite ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A homogeneous preparation of casein kinase 2 has been isolated from the phytopathogenic fungus Verticillium dahliae (the parasite of cotton). The enzyme consists of three subunits with molecular masses of 53, 41, and 38 kDa. Highly specific immune serum against casein kinase 2 has been obtained. By means of immunoblotting, enzyme-linked immunosorbent assay (ELISA), and immunochemical isolation on protein A-Sepharose, it is shown that the amount of casein kinase 2 increases under heat shock conditions (at least in part due to the synthesis de novo), while the synthesis of the majority of other proteins falls. The activity of casein kinase 2 is supressed during heat shock and so does not correlate with its content. The results give an evidence for the two-step model of casein kinase 2 regulation during heat shock.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310108
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  • 105
    Electronic Resource
    Electronic Resource
    Effect of maturation media on male pronucleus formation in pig oocytes matured in vitro (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 68-71 
    Details
    ISSN: 1040-452X
    Keywords: Maturation ; Fertilization ; Male pronucleus formation ; Culture medium ; Cysteine ; Pig oocyte ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The present study was carried out to examine the effect of maturation media on male pronucleus formation of pig oocyte matured and fertilized in vitro. Follicular oocytes collected from prepubertal gilts at a local slaughter house were cultured (36 h) in three different media (mTCM-199, Waymouth MB 752/1, and mTLP-PVA), fertilized in vitro, and assessed for nuclear maturation and male pronucleus formation. The addition of 10% (v/v) pig follicular fluid (pFF) to maturation media significantly increased the rate of nuclear maturation of pig oocytes (P 〈 0.01), whereas the rate of nuclear maturation of pig oocytes among three different media did not differ. However, the rate of male pronucleus formation of pig oocytes was significantly higher in pig oocytes matured in Waymouth MB 752/1 with or without pFF than in oocytes matured in the other two media (P 〈 0.01). In experiment 2, the addition of cysteine (the same concentration as in Waymouth medium, 0.57 mM), to mTLP-PVA significantly increased the rate of male pronucleus formation of pig oocytes compared with the control (P 〈 0.01). The results indicate that the composition of maturation medium affects the ability of pig oocytes to form male pronuclei following sperm penetration; media containing a high concentration of cysteine (possibly as a substrate of glutathione), such as Waymouth MB 752/1, can remarkably promote this ability.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310112
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  • 106
    Electronic Resource
    Electronic Resource
    Expression of growth factor ligand and receptor genes in the preimplantation bovine embryo (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 87-95 
    Details
    ISSN: 1040-452X
    Keywords: Mammalian development ; mRNA phenotyping ; RT-PCR ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The sensitive technique of mRNA phenotyping with the reverse transcription-polymerase chain reaction was employed to determine the patterns of gene expression for several growth factor ligand and receptor genes during bovine preimplantation development. Several thousand bovine embryos encompassing a developmental series from one-cell zygotes to hatched blastocysts were produced by the application of in vitro maturation, fertilization, and oviductal epithelial cell embryo coculture methods. Transcripts for transforming growth factor (TGF-α) and platelet-derived growth factor (PDGF-A) are detectable in all preimplantation bovine stages as observed in the mouse. Transcripts for TGF-β2 and insulin-like growth factor (IGF-II) and the receptors for PDGF-α, insulin, IGF-I, and IGF-II are also detectable throughout bovine preimplantation development, suggesting that these mRNAs are products of both the maternal and the embryonic genomes in the cow, whereas in the mouse they are present only following the activation of the embryonic genome at the two-cell stage. In contrast to the mouse embryo, IGF-I mRNA was detected within preimplantation bovine embryos. Basic fibroblast growth factor (bFGF) is a maternal message in the bovine embryo, since it is only detectable up until the eight-cell embryo stage. Bovine trophoblast protein (bTP) mRNA was detectable within day 8 bovine blastocysts. As was observed in the mouse, the transcripts for insulin, epidermal growth factor (EGF), or nerve growth factor (NGF) were not detectable in any bovine embryo stage. Analyses of this type should aid the development of a completely defined culture medium for the more efficient production of preimplantation bovine embryos.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310202
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  • 107
    Electronic Resource
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    Cyanide-resistant reduction of nitroblue tetrazolium and hydrogen peroxide production by the rabbit blastocyst (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 114-121 
    Details
    ISSN: 1040-452X
    Keywords: Trophoblast ; NAD(P)H oxidase ; NBT ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The ability of the rabbit blastocyst to reduce nitroblue tetrazolium (NBT) to formazan in the presence of cyanide was assayed as an indicator of extramitochondrial oxidase activity capable of generating the superoxide radical. A cytochemical method initially developed for the detection and localization of hydrogen peroxide production at the ultrastructural level in phagocytosing leukocytes (Briggs et al.: J Cell Biol 67:566, 1975) was also applied to the blastocyst. The results demonstrate that the rabbit blastocyst acquires the ability to reduce NBT by a cyanide-insensitive process and to generate hydrogen peroxide between the fourth and fifth days postcoitum. The enzymatic activity responsible is apparently an NAD(P)Hdependent oxidase in the outer, microvillous plasma membrane of the trophoblast.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310205
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  • 108
    Electronic Resource
    Electronic Resource
    Perivitelline space of mammalian oocytes: Extracellular matrix of unfertilized oocytes and formation of a cortical granule envelope following fertilization (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 135-143 
    Details
    ISSN: 1040-452X
    Keywords: Cortical reaction ; ECM ; PVS ; Polyspermy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Extracellular matrices (ECM) present around unfertilized and fertilized mammalian oocytes were studied ultrastructurally in samples prepared in the presence of ruthenium red to facilitate stabilization of extracellular materials. Unfertilized mouse, hamster, and human oocytes have an ECM comprising granules and filaments in their perivitelline spaces (PVS). This matrix is more abundant in the human than in hamsters and mice. The granule/filament matrix appears identical to the matrix seen between cumulus and corona radiata cells following ruthenium red processing and previously shown to comprise protein and hyaluronic acid. By including ruthenium red during fixation, it is possible to demonstrate the existence of cortical granule exudate in the PVS of fertilized oocytes from hamsters, mice, and humans. Much of the cortical granule exudate is trapped in the PVS and forms a new coat around the fertilized oocyte. This material is particulate when stained with ruthenium red and appears to be uniformly dispersed around the entire oocyte surface. We refer to this new coat as the cortical granule envelope. This envelope is observed in the PVS of all developmental stages up to and including blastocysts in all three species. Following hatching of mouse and hamster blastocysts, the cortical granule envelope is no longer present. Possible functions of this envelope are discussed.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310208
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  • 109
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992) 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310301
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  • 110
    Electronic Resource
    Electronic Resource
    Expression of ribosomal protein genes in mouse oocytes and early embryos (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 182-188 
    Details
    ISSN: 1040-452X
    Keywords: Ribosomal protein mRNAs ; Blot hybridization ; Ribosome biosynthesis ; Preimplantation development ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The quantitative changes in the mRNAs for ribosomal proteins L7a, L18a, and S15 were assayed in slot hybridization experiments using labeled cRNA probes with total RNA from late growth-phase oocytes, ovulated eggs, and early embryos through the blastocyst stage. All three mRNAs showed a similar developmental pattern of prevalence, but their copy numbers per oocyte or embryo fluctuated according to developmental stage. There are on an average about 17,000 copies of each mRNA in the late growth-phase oocyte; this number drops to one-fifth to one-tenth in the ovulated egg and two-cell embryo but increases rapidly during cleavage to about 25,000 in the eight-cell embryo and about 42,000 in the blastocyst. A comparison of the levels of these mRNAs with the reported rates of ribosomal protein synthesis (LaMarca and Wassarman, 1979) suggests that, in late growth-phase oocytes, ribosomal protein synthesis is regulated primarily at the translational level and is kept low by some factor limiting mRNA utilization. On the other hand, the high rate of ribosome biosynthesis during early embryogenesis from the two-cell stage onward appears to involve the coordinate activation and transcription of ribosomal RNA and ribosomal protein genes coupled with the immediate translational utilization of ribosomal protein mRNAs.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310304
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  • 111
    Electronic Resource
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    Insulin-like growth factor-1 stimulates growth of mouse preimplantation embryos in vitro (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 195-199 
    Details
    ISSN: 1040-452X
    Keywords: IGF-1 ; Inner cell mass ; Trophectoderm ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Because recent studies have particularly implicated the insulin growth factor family in early development, the effects of insulin-like growth factor (IGF-1) on the development of mouse embryos in vitro were investigated in detail. When added to the medium for culture of two-cell embryos, IGF-1 stimulated the number of cells in the resultant blastocysts after 54 hr, entirely by increasing the number of cells in the inner cell mass (ICM) (16.0 ± 0.5 vs. 12.6 ± 0.5 cells/ICM). This stimulation was also achieved when ICMs were isolated from blastocysts prior to culture for 24 hr with IGF-1 (22.3 ± 1.0 vs. 17.5 ± 0.8 cells/ICM). There was no effect of IGF-1 on trophectoderm (TE) cell proliferation. In morphology studies, IGF-1 also increased the proportion of blastocysts (62% ± 3% vs. 49% ± 4%) while decreasing the number of embryos remaining as morulae (32% ± 3% vs. 38% ± 2%) or in the early cleavage stages (7% ± 3% vs. 13% ± 3%) after 54 hr culture from the two-cell stage. All these effects were achieved with EC50s of approximately 60 pM IGF-1, which is in the range for IGF-1 receptor mediation; however, cross reaction with insulin, IGF-2, or other unknown receptors is not excluded. Nonetheless, the results show that physiological concentrations of IGF-1 (17-170 pM, 0.1-1 ng/ml), which have been observed in the reproductive tract, affect the early embryo, suggesting a normal role for this factor in the regulation of growth of the developing conceptus before implantation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310306
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  • 112
    Electronic Resource
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    Evidence for the presence of an integrin cell adhesion receptor on the oolemma of unfertilized human oocytes (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 215-222 
    Details
    ISSN: 1040-452X
    Keywords: RGD ; α5 ; Immunobeads ; Integrins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Arg-Gly-Asp peptide (RGD), contained in several extracellular matrix proteins such as fibronectin, laminin, vitronectin, and collagen, is a tripeptide that plays a role as a recognition sequence in many cell-to-cell and cell-to-matrix adhesion mechanisms, through its interaction with several receptors of the integrin family. We previously described the ability of the oolemma of hamster oocytes to bind GRGDTP coupled to the surface of activated immunobeads and demonstrated that RGD-containing oligopeptides inhibit the adhesion of human and hamster spermatozoa to zona-free hamster oocytes and their subsequent penetration. In the present experiments, we show, utilizing immunobeads coated with an RGD-containing peptide (PepTiteTM 2000), that the oolemma of unfertilized human eggs is also able to recognize this adhesion sequence. The binding of PepTiteTM 2000-coated immunobeads to the oolemma was inhibited by the oligopeptide GRGDTP as well as by fibronectin and laminin. When immunobeads were prepared with a PepTiteTM concentration of 10 μg/ml, GRGDTP 150 μg/ml, laminin 80 μg/ml, and fibronectin 60 μg/ml inhibited bead rosetting on the egg surface. These data suggest that a specific binding moiety for RGD is present on the human egg surface. The binding of fibronectin to the oolemma was also demonstrated by the rosetting of immunobeads coupled with antifibronectin antibody to human oocytes after their exposure to 1 mg/ml free fibronectin. Such binding of fibronectin to the oolemma could be inhibited by coincubation with a monoclonal antibody directed against the cell adhesion fragment of fibronectin. In addition, oolemmal rosetting of immunobeads coupled with a monoclonal antibody directed against the α5 subunit, usually part of the fibronectin receptor VLA 5 (α5β1), provided additional evidence that a putative fibronectin receptor is present on the oolemma of human eggs.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310309
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  • 113
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    The interaction between exogenous DNA and sperm cells (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 161-169 
    Details
    ISSN: 1040-452X
    Keywords: Sperm cell ; Recombinant DNA ; Fertilization ; Genetic transformation ; Transgenic animals ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Epididymal sperm cells, incubated with plasmid DNA, showed a spontaneous tendency to interact with the exogenous nucleic acid. We have investigated the molecular basis of such interaction. Exogenous DNA is taken up by sperm cells over a 15- to 20-min period and is specifically localized on the nuclear area of the sperm head. DNA was reversibly bound to spermatozoa since it can be competed out by excess of cold competitor DNA or by other polyanions as heparin and dextran sulphate. By contrast, poly-L-lysine, a polycation, favours the uptake. DNA molecules of large size (7 kb) were preferentially taken up as compared to smaller ones (150-750 bp). Acidic proteins were also taken up and concentrated, as for DNA, at the nuclear level. These data strongly suggested that ionic interactions may occur between foreign molecules and a substrate located in the sperm head. On the basis of Southwestern analysis, a sperm head protein(s) of 30-35 KD is identified as potential substrate for exogenous DNA binding. Moreover, we have found that seminal plasma contains factor(s) which abolish sperm permeability, exerting a powerful inhibitor effect on DNA uptake. The presence of a specific binding protein for the DNA and of a factor inhibiting such interaction support the existence of a mechanism controlling, through specific factors, the sperm-DNA interaction.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310302
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  • 114
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    Joint effects of sodium chloride, glutamine, and glucose in mouse preimplantation embryo culture media (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 189-194 
    Details
    ISSN: 1040-452X
    Keywords: Simplex optimized medium ; NaCl ; Osmolyte ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A new medium, SOM, produced by simplex optimization, has been used to study the joint effects of NaCl, glutamine, and glucose on the development of outbred CF1 mouse zygotes to the blastocyst stage. Contrary to previous reports, glucose has no significant inhibiting effect on development to the blastocyst stage in this medium. Even in the presence of 5 mM glucose, 70% of the embryos develop to at least four cells, and 60% reach the blastocyst stage. Raising the concentration of NaCl from 75 to 125 mM, in the absence of glutamine, progressively inhibits development. Moreover, the response to glutamine depends on the concentration of NaCl in the medium. When the NaCl concentration is low, glutamine inhibits development. In contrast, when the NaCl concentration is high, glutamine protects against the inhibitory effect of the salt. We propose that glutamine protects against high concentrations of NaCl in the medium by acting as an organic osmolyte.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310305
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  • 115
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    Subzonal insemination with a single spermatozoon using manipulation assisted sperm adhesion onto the ooplasmic membrane in mouse ova (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 223-229 
    Details
    ISSN: 1040-452X
    Keywords: Mouse ; Spermatozoa ; Acrosome reaction ; Sperm injection ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A simple and successful method of microinjection of a single spermatozoon under the zona pellucida of a mouse oocyte has been developed. A characteristic of this method is that the tip of the sperm injection needle pierces the zona pellucida without touching the ooplasmic membrane. All the ova (277) used for this series of experiments had normal morphology after the injection procedure. Spermatozoa preincubated in culture medium for capacitation and those treated with ionophore A23187 for induction of acrosome reaction were used. In combination with some of these injections, a manipulation assisting the adhesion of the sperm head onto the ooplasmic membrane was employed. The fertilization rate (67.3%) of the ova injected with the ionophore-treated sperm using the sperm-adhesion treatment was significantly higher (P〈0.005) than that obtained by the injection of the preincubated sperm without applying the adhesion treatment (23.6%). All three of the recipients that received the 24 fertilized ova became pregnant and gave birth to 11 off-spring (45.8%). The inseminations performed with the sperm-adhesion treatment using the immotile sperm from the preincubated population and/or those from the ionophore-treated population did not result in fertilization in any case. These results suggest that the fertilization rate of subzonal insemination with motile ionophore-treated sperm can be improved by applying the sperm-adhesion treatment and that sperm motility might be involved in the establishment of fertilization, even after the adhesion of the sperm head with the mouse ovum membrane.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310310
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  • 116
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    Sex-related differences in developmental rates of bovine embryos produced and cultured in vitro (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 249-252 
    Details
    ISSN: 1040-452X
    Keywords: Sexual dimorphism ; In vitro ; Early development ; Cattle ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The classical concept of sex determination in mammals is that a Y chromosomal gene controls the development of the indifferent gonad into a testis. Subsequent divergence of sexual phenotypes is secondary to this gonadal determination. The most likely candidate gene is SRY (sex-determining region Y) in humans, and Sry in mouse. However, several lines of evidence indicate that sexual dimorphism occurs even before the indifferent gonad appears. Here we present evidence that bovine male embryos generally develop to more advanced stages than do females during the first 8 days after insemination in vitro. Corresponding relationships between both cell numbers and mitotic indices and sex were also seen. Although it is not clear whether this phenomenon involves factors originating before or after fertilization, these findings suggest that sex-related gene expression affects the development of embryos soon after activation of the embryonic genome and well before gonadal differentiation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310404
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  • 117
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    Assessment of Pisum sativum agglutinin in identifying acrosomal damage in stallion spermatozoa (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 23-27 
    Details
    ISSN: 1040-452X
    Keywords: Assay ; Lectin ; binding ; Fluorescence ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The use of fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) was evaluated for its ability to distinguish acrosome-intact from acrosome-damaged stallion spermatozoa. Incubation of fresh (acrosomeintact) and frozen-thawed (acrosome-damaged) spermatozoa with FITC-PSA resulted in acrosome-intact spermatozoa that exhibited no fluorescence, while acrosome-damaged spermatozoa exhibited fluorescent staining over the rostral portion of the head and equatorial segment. Experiments using mixtures of various ratios of acrosome-intact and acrosome-damaged spermatozoa determined the precision (intrasample coefficient of variation), and linearity (increased percentage of spermatozoa with PSA binding, with increased percentage of frozenthawed spermatozoa in a sample) of FITC-PSA binding. The binding of FITC-PSA increased in samples as the portion of frozen-thawed (acrosome-damaged) to fresh (acrosomeintact) spermatozoa increased. A positive correlation existed (r = 0.98, P 〈 0.05) between the percentage of FITC-PSA bound sperm and the proportion of damaged spermatozoa added to a sample. Location of PSA lectin binding on acrosome-damaged spermatozoa, determined by electron microscopy using gold-conjugated PSA, was to components of the outer acrosomal membrane and acrosomal matrix. These results demonstrate that FITC-PSA binding may be useful in determining acrosomal integrity of fresh and frozen-thawed stallion spermatozoa. © 1992 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080320105
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  • 118
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    A transient rise in intracellular Ca2+ is a precursor reaction to the zona pellucida-induced acrosome reaction in mouse sperm and is blocked by the induced acrosome reaction inhibitor 3-quinuclidinyl benzilate (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 41-50 
    Details
    ISSN: 1040-452X
    Keywords: Fluo-3 ; Intracellular Ca2+ transient ; QNB ; Population kinetics ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The acrosome reaction induced by the zona pellucida in mouse sperm has been shown to proceed in two stages experimentally distinguishable by the fluorescent probe chlortetracycline. Entry into the first stage of sperm bound to isolated, structurally intact zonae pellucidae is blocked by the compound 3-quinuclidinyl benzilate. In this study, we show, utilizing the fluorescent Ca2+ indicator fluo-3, that the first stage of the zona-induced acrosome reaction is characterized by an increase in intracellular Ca2+, followed by a decrease as the acrosome reaction proceeds. This calcium transient is completely suppressed by 3-quinuclidinyl benzilate. We conclude that the Ca2+ transient is induced by the zona pellucida and is required for the zona-induced acrosome reaction. Blockage of this sperm intracellular Ca2+ transient provides a mechanism for the inhibitory action of 3-quinuclidinyl benzilate on the zona-induced acrosome reaction in mouse sperm. © 1992 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320108
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    Natural degenerating mitochondria in ovarian follicles of a cyprinodontidae fish, Epiplatys spilargyreus (teleost) (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 67-72 
    Details
    ISSN: 1040-452X
    Keywords: Ultrastructure ; Lysosomes ; Vitellogenesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: This study examines the evolution of mitochondria in the follicular cells during the development of the ovarian follicle in the teleostean fish Epiplatys spilargyreus. The mitochondria are few in number until the end of previtellogenesis; their matrix is dense, and their cristae are well developed. They proliferate during vitellogenesis and then are modified by deterioration of their matrix. Multilamellar structures are organized in the vacuolized mitochondria. During postvitellogenesis, these modifications become more advanced. The mitochondria degenerate, leaving vacuoles that contain heterogeneous structures, which will be released into the intercellular spaces. At the end of these mitochondrial transformations, the follicular cells degenerate. They release the elements which will participate in forming the secondary envelope. © 1992 Wiley-Liss, Inc.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080320111
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992) 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320201
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    Tight junctions and cavitation in the human pre-embryo (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 81-87 
    Details
    ISSN: 1040-452X
    Keywords: Morula ; Blastocoele ; Zonulae occludentes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the human morula, tight junctions are found between all cell pairs, at all levels of cellular apposition, associated with underlying masses of microfilaments. In cavitating morula, lanthanum tracer gained access to the intercellular spaces, except at the intersections with nascent extracellular cavities, marking the first assembly of zonulae occludentes. Presumptive trophectoderm cells contained vacuoles and larger cavities often associated with secondary lysosome-like bodies. Since the vacuoles and intracellular and extracellular cavities contain electron-dense polygranules of about 23 nm diameter, they may have common origins. In trophectoderm cells of the early blastocyst, the large intracellular vacuoles and cavities were absent, and the zonulae occludentes were located apically. Mechanisms for nascent blastocoele formation are discussed. © 1992 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080320113
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    Modulation of vascular cell behavior by transforming growth factors β (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 121-126 
    Details
    ISSN: 1040-452X
    Keywords: Vascular cells ; TGF-β ; Cell surface binding ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The vascular cell responses to the type 1, 2, and 3 isoforms of transforming growth factor-β (TGF-β1, TGF-β2, TGF-β3) were studied using bovine aortic endothelial (BAECs) and smooth muscle cells (BASMC3) as well as rat epididymal fat pad microvascular endothelia (RFCs). Three distinct bioassays indicated that TGF-β3 elicits results that do not differ significantly from those of the TGF-β1 isoform in all three cell populations. These assays are: inhibition of proliferation, cell migration, and neovascularization. By contrast the cellular responses to TGF-β1 and TGF-β3 differed from those to TGF-β2. Three distinct receptor assays revealed the preesnce of type I and type II TGF-β1 cell surface binding proteins on BAECs, BASMCs, and RFCs. Experimentation to decipher cell surface binding by the different isoforms revealed that iodinated TGF-β1 bound to the surface of all three vascular cell types can be competed off in similar fashion by either TGF-β1 or TGF-β3; however, competition with TGF-β2 produced unique binding profiles dependent on the cell type examined. The ratios of type I to type II TGF-β receptors in these three vascular cell types vary from 1:1 in BAECs to 1.5:1 in RFCs to 3:1 in BASMCs and can be correlated with the differences noted in cellular responses to TGF-β1 and TGF-β2 in proliferation, migration, and in vitro angiogenic assays.In summary, both the TGF-β1 and TGF-β3 isoforms of the transforming growth factor-β family evoke comparable responses in proliferation, migration, angiogenic and cell surface bindinga ssays using three distinct vascular cell types, while the biofunctions of TGF-β2 on these cells are distinct. These findings support the hypothesis that there are different responses to the TGF-βs depending on the cell type and experimental conditions as well as the TGF-β concentration and isoform. © 1992 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080320207
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    Müllerian inhibiting substance in reproduction and cancer (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 168-172 
    Details
    ISSN: 1040-452X
    Keywords: MIS ; Ovarian cancer ; Fetal testes ; Ocular melanoma ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: During embryogenesis normal male phenotypic development requires the action of Müllerian Inhibiting Substance (MIS) which is secreted by Sertoli cells of the fetal testis. As testes differentiate in genetic (XY) males, they produce MIS which causes regression of the Müllerian ducts, the anlagen of the female reproductive tract. Soon thereafter, testicular androgens stimulate the Wolffian ducts. In females, on the other hand, MIS is not produced by grandulosa cells until after birth, before which, estrogens induce Müllerian duct development, while the Wolffian ducts passively atrophy in the absence of androgenic stimulation. High serum MIS levels in males are maintained until puberty, whereupon they fall to baseline levels. In females MIS is undetectable in serum until the peripubertal period when values approach the baseline levels of males. This distinct pattern of sexual and ontogenic expression presupposes and requires tight regulation.MIS may play a role in gonadal function and development. Our laboratory has shown that an important role for ovarian MIS is to inhibit oocyte meiosis, perhaps providing maximal oocyte maturation prior to selection for ovulation and subsequent fertilization. Furthermore, Vigier et al. (Development 100:43-55) have recently obtained evidence that MIS may influence testicular differentiation, coincident with inhibition of aromatase activity. Current structure-function studies demonstrate that MIS, like other growth regulators in its protein family, requires proteolytic cleavage to exhibit full biological activity. MIS can be inhibited by epidermal growth factor. This antagonism, which is common to all MIS functions so far investigated, is associated with inhibition of EGF receptor autophosphorylation. We have provided evidence that bovine MIS can inhibit female reproductive tract tumors arising in adults. More recent work with highly purified recombinant human MIS (rhMIS) has extended these early observations, showing that this recombinantly made fetal inhibitor can also suppress tumors of Müllerian duct origin and thus may prove to be useful in the clinical management of gynecologic neoplasms. Recent investigations have identified ocular melanoma as another potential target for rhMIS therapy in humans. © 1992 Wiley-Liss, Inc.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320213
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    Localization of ras proto-oncogene expression during development in Xenopus Laevis (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 187-195 
    Details
    ISSN: 1040-452X
    Keywords: Differentiation ; Development ; RNA ; In situ ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The expression of the ras protooncogene was investigated in Xenopus laevis, throughout development, by in situ hybridization using a 35S-labelled antisense RNA probe. During oogenesis, the ras RNA was strongly expressed in the cytoplasm of previtellogenic oocytes and further diluted between yolk platelets; no specific localization of transcripts was observed. The signal density was particularly weak over embryo sections until the tailbud stage. On the other hand, a high level of ras RNA expression was detected on sections through the young tadpoles. An intense labelling was observed in several areas, including the branchial apparatus, gut, somites, nervous system, and lens. It is noteworthy that the heterogeneity of labelling increases as tadpoles grow older. Together, these results are discussed in relation to cellular events appearing throughout the early development.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320302
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    Zygotic gene activation in the mouse embryo: Involvement of cyclic adenosine monophosphate-dependent protein kinase and appearance of an AP-1-like activity (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 209-216 
    Details
    ISSN: 1040-452X
    Keywords: Transcription ; Transcription factor ; Protein phosphorylation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Protein phosphorylation catalyzed by the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) is implicated in regulating zygotic gene activation in the two-cell mouse embryo (Poueymirou and Schultz; Dev Biol 133:588-599, 1989). We now provide evidence that H8, which is a PKA inhibitor, inhibits expression of an hsp70-driven β-galactosidase reporter gene and that the concentration-dependence of this inhibition is similar to that for inhibiting expression of a stage-specific gene(s) that is a product of zygotic gene activation. We also demonstrate that neither cAMP nor serum can stimulate the expression, as detected by a histochemical assay, of a cAMP response element (CRE)- or serum response element (SRE)-driven β-galatosidase reporter gene, respectively in either germinal vesicle-intact oocytes or aphidicolin-arrested one-cell embryos that are chronologically at the tw-cell stage. In contrast, although 12-O-tetradecanoyl phorbol-13-acetate (TPA) does not stimulate expression of a TPA response element (TRE)-driven β-galatosidase reporter gene in germinal vesicle-intact oocytes, it stimulates such expression in aphidicolin-arrested one-cell embryos. Moreover, TPA can stimulate the expression of either a CRE- or an SRE-driven β-galatosidase reporter gene in such embryos. Results of these studies further implicate protein phosphorylation in regulating zygotic gene activation, along with its role in modulating enhancer function in the early mouse embryo.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320305
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    Microtubule distribution during fertilization in the rabbit (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 271-276 
    Details
    ISSN: 1040-452X
    Keywords: Egg ; Oocyte ; Pronuclei ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The distribution of microtubles was studied during fertilization of the rabbit oocyte by immunofluorescence microscopy after staining with an anti-α-tubulin antibody. In ovulated oocytes, microtubules were found exclusively in the meiotic spindle. At fertilization, the paternal centrosome generated sperm astral microtubules. During pronclear development, the sperm aster increased in size, and microtubules extended from the male pronucleus to the egg center and towards the female pronucleus. These observations indicate that microtubules emanating from the sperm centrosome were involved in the movements leading to the union of the male and female pronuclei. At late pronuclear stage, microtubules surrounded the adjacent pronuclei. The mitotic spindle that emerged from the perinuclear microtubules contained broad anastral poles.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320313
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    Synthesis and modification of D7 protein during Xenopusoocyte maturation (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 293-301 
    Details
    ISSN: 1040-452X
    Keywords: Maternal mRNA ; Oocyte maturation ; Protein modification ; MPF ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Xenopus maternal mRNA D7 is translationally repressed during oogenesis, only becoming recruited into polysomes during oocyte maturation, with D7 protein being detectable for the first time prior to germinal vesicle breakdown (GVBD). The synthesis of D7 protein was found to be induced by a variety of maturation-promoting agents including cyclin, c-mos and crude preparations of MPF. D7 protein induced by all these agents is post-translationally modified and exists as a number of variants of differing molecular weight. In contrast to endogenous D7 mRNA, D7 RNA injected into the stage VI oocyte is efficiently translated, resulting in the accumulation of predominantly unmodified D7 polypeptides, which become increasingly modified during oocyte maturation to produce a pattern of polypeptides similar to those derived from endogenous D7 mRNA. Thus, the system that results in the post-translational modification of the D7 protein is itself activated during oocyte maturation. The nature of the protein modification is not known but does not appear to be phosphorylation. The translation of exogenous D7 RNA in the stage VI oocyte does not lead to translational derepression of endogenous D7 mRNA.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320315
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    Glycogen breakdown in cleaving xenopus embryos is limited by ADP (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 354-362 
    Details
    ISSN: 1040-452X
    Keywords: Glycolysis, Embryos, Metabolism, Pyruvate kinase, Malic enzyme ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Xenopus eggs contain large stores of glycogen, but this glycogen is not glycolytically processed during cleavage. The Embden-Meyerhof pathway is inhibited by the absence of pyruvate kinase activity in vivo, and lactate and pyruvate are present at relatively low levels. In the late blastula, just preceding gastrulation, lactate levels increase, indicating the onset of glycogen breakdown and glycolytic flux. Glycolysis from microinjected [14C]glucose-6-phosphate could be transiently activated, however, by the coinjection of ADP into fertilized eggs, and constitutively activated by the injection of the ATPase potato apyrase, indicating the presence of all enzymes necessary for glycolytic activity. The isozyme profiles of pyruvate kinase and malic enzyme, two enzymes involved in carbon metabolism during cleavage or in the subsequent activation of glycogen breakdown, do not change between the egg and gastrula stages. These data suggest that the activation of glycogen breakdown and glycolysis in the late blastula is probably not a result of new gene activity but may be the metabolic consequence of increased free ADP that is then able to support the pyruvate kinase reaction.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320408
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    Migration of centromere proteins in rabbit spermatids (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 369-377 
    Details
    ISSN: 1040-452X
    Keywords: Spermiogenesis ; Immunocytochemistry ; Confocal microscopy ; Nuclear proteins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Human autoantibodies were used to localize centromere proteins by immunoelectron microscopy, immunofluorescence, and confocal microscopy in isolated cells and in cryosections of rabbit testis. A computer-assisted three-dimensional reconstruction of the positions and sizes of fluorescent spots allowed us to follow their movements during the different phases of spermiogenesis. In very young spermatids, the centromeres were distributed within a space separated from both the external nuclear limits and the nuclear core. They moved towards the nuclear limits and the nuclear core. They moved towards the nuclear center in cap phase spermatids, where they clustered into a few large centromeric masses. In preelcngating spermatids, the immunolabeled proteins were dispersed within an equatorial area, where they formed one large mass. In late spermatids, the mass moved towards the posterior part of the nucleus, and, in the spermatozoon, the two basal knobs located at the base of the nuclei were the only strongly immunolabeled structures, while no labeling of the main part of the nucleus was observed. Since the number of centromeres remained close to the number of chromosomes until the cap phase of spermatid differentiation, we hypothesize that the labeling of young spermatids corresponds to centromeric proteins associated with their specific DNA counterparts, while the centromere proteins, possibly detached from their DNA loci, were released from nuclei of old spermatids in the same way as are histones and transition proteins.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320410
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    Collection of acrosome-reacted human sperm using monoclonal antibody-coated paramagnetic beads (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 389-393 
    Details
    ISSN: 1040-452X
    Keywords: Sperm penetration assay ; Binding ; Fertilizing ability ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A monoclonal antibody (MAb) against human acrosome-reacted sperm was attached to paramagnetic polystyrene beads. Human sperm prepared by the swim-up method were (1) incubated in m-BWW, (2) incubated and ionophore treated, or (3) incubated with 5% seminal fluid. After treatment, sperm were mixed with the beads and incubated for 1 hr. Variously treated sperm showed different binding abilities to the beads. Sperm bound to the beads were collected by a magnet and subjected to triple staining. Most of the collected sperm were acrosome reacted. The results suggested that the beads can be used to estimate the acrosomal status of sperm, and that the use of antibody-coated paramagnetic beads provides a convenient way of collecting acrosome-reacted sperm. The acrosomal status detected by the beads was also compared with the ability of sperm to fuse with zonafree hamster eggs. It was found that greater bead-binding ability correlated with more sperm fusing with zona-free hamster eggs.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320413
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    Preimplantation genetics. Edited by Yury Verlinsky and Anver Kuliev, Plenum Publishing Corp., New York, 1991,325 pp, $85 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 409-409 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320417
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    Other books received (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 409-409 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320420
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    Structural organization of surface domains of sperm mitochondria (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 89-98 
    Details
    ISSN: 1040-452X
    Keywords: Midpiece mitochondria ; Outer mitochondrial membrane ; Sperm cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Sperm mitochondria are assembled into an organized sheath surrounding the outer dense fibers and axoneme of the flagellar midpiece. Each mitochondrion is arranged so that its surface faces three different cellular organelles including the plasma membrane, neighboring mitochondria and the outer dense fiber-axoneme complex. In this manuscript we present data on structural differentiations of these three different surface domains of the outer mitochondrial membrane. We demonstrate that the apposed surfaces of adjacent mitochondria are joined by a two dimensional network of studs unique to this domain. By contrast, the surface domain facing the outer dense fiber-axoneme complex exhibits a different, but highly ordered structural organization, evident as a parcrystalline network of parallel stripes; this domain is further distinguished by its exclusive association with a midpiece-specific cytoskeletal complex. These differentiations are not seen on the surface domain of mitochondria which faces the plasma membrane. The implications of the mosaic composition of the outer mitochondrial membrane in the assembly and function of the mitochondrial sheath are discussed. © 1992 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330113
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    F-Actin in acrosome-reacted boar spermatozoa (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 99-107 
    Details
    ISSN: 1040-452X
    Keywords: Spermatozoa ; F-actin ; Acrosome reaction ; Boar ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Biochemical and immunoelectron microscopic methods have been used to analyze the distribution of actin in boar spermatozoa and its state of aggregation before and after acrosome reaction. F-actin was detected on sperm head and tail by electron microscopy using an improved phalloidin probe: incubation with a fluorescein-phalloidin complex and an anti-fluorescein antibody, followed by labeling with protein A-gold complex. Gold particles, indicating the presence of F-actin, were localized on the sperm surface of the acrosome-reacted spermatozoa. Specific labeling was localized (1) between the outer acrosomal membrane and the plasma membrane in the equatorial region, (2) between the outer surface of the fibrous sheath and the plasma membrane in the postacrosomal region, (3) around the connecting piece and the neck region, and (4) on the external surface of the fibrous sheath in the principal piece of the tail. Furthermore, after NP-40 extraction, the SDS-PAGE revealed a difference in solubility between reacted and unreacted boar spermatozoa, reflecting actin polymerization. We conclude that most actin in the acrosome reacted boar spermatozoa is polymeric. © 1992 Wiley-Liss, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330114
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    Animal applications of research in mammalian development, Volume 4 in current communications in cell and molecular biology, edited by Roger A. Pedersen, Anne McLaren, and Neal L. First, 1991, Cold Spring Harbor Laboratory Press, Plainview, New York, 334 pp, $44 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 116-116 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330117
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    Announcement (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 117-117 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330120
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    Evidence for differential maturation of reciprocal sperm segregants in the murine RB(6.16) translocation heterozygote (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 394-398 
    Details
    ISSN: 1040-452X
    Keywords: Sperm function ; Aging ; Chromosomal rearrangement ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The fertilizing ability of unaged sperm and those aged experimentally in the cauda by surgically ligating the corpus epididymis in males carrying the Rb(6.16) translocation was studied. Chromosomally normal females were inseminated with unaged sperm delivered by males mating at 3-day intervals, and aged sperm were studied after matings on 6-14 postoperative days. The sperm chromosome complement was analyzed in first-cleavage metaphase zygotes after sequential G- and C-banding of the chromosomes. Of 283 metaphasic zygotes in the control group, 183 (or 64.7%) were analyzed and showed a ratio of 2.7:1 for chromosomally normal and balanced segregants of the translocation, deviating significantly (P 〈 0.001) from the expected 1:1. The ratio of X- to Y-bearing sperm also deviated from expected (P 〉 0.01) mostly due to a significant deficiency (P 〉 0.05) of balanced sperm that were X-bearing. Fertilized oocytes were recovered from matings of 10 males on days 6-8 post-operatively, and, of 139 metaphasic one-cell zygotes, 101 (or 72.3%) were analyzed. These showed a Mendelian ratio of 1:1 for normal and balanced segregants. The sex ration in the aged group (57Y:41X) also showed no deviation from 1:1. The results, which reveal significant physiological distortions for both the segregation and the sex ratios in males heterozygous for the Rb(6.16) translocation, suggest that differential maturation of the translocation-bearing sperm and the chromosomally normal reciprocal exists. The findings further support the concept that sperm chromosomal complement affects their maturation and function, and that factors on chromosome 6 and the X or Y chromosome additively affect sperm function. © 1992 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080320414
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    A rat sperm flagellar surface antigen that originates in the testis and is expressed on the flagellar surface during epididymal transit (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 399-408 
    Details
    ISSN: 1040-452X
    Keywords: Monoclonal antibody ; MC31 ; Spermatogenesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We identified a rat sperm flagellar surface antigen using an IgG1 monoclonal antibody (MC31) against rat epididymal sperm. Avidin-biotin-peroxidase immunohistochemistry demonstrated that the antigen was first expressed in the cytoplasm of early primary spermatocytes, then gradually became restricted to the principal piece of the sperm flagellum during spermatogenesis. However, when the sperm reached the corpus epididymidis, the antigen was expressed on the surface of both the principal piece and the midpiece of the flagellum. The epithelial cells of the epididymis were not stained with MC31. Immunogold electron microscopy showed that the antigen was present on the surface of the sperm flagellar plasma membrane. Immunoblotting of Triton X-100 extracts of epididymal sperm after one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions demonstrated that MC31 detected a major antigen of 26,000-28,000 daltons (26-28K). Two-dimensional isoelectric focusing and SDS-PAGE indicated that the 26-28K antigen had an isoelectric focusing point (pl) of 5.8-5.3; minor antigens were also detected from 26K (pl 5.8) to 35K (pl 5.0). These results indicate that the antigen recognized by MC31 is an acidic 26-35K protein that originates in the testis, is integrated into the sperm flagellar plasma membrane of the principal piece during spermatogenesis, and then is expressed on the entire flagellar surface during epididymal transit. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080320415
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  • 139
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    Characterization of low Mr Zona Pellucida binding proteins from boar spermatozoa and seminal plasma (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 108-115 
    Details
    ISSN: 1040-452X
    Keywords: Zona binding proteins ; Seminal plasma ; Fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A group of low Mr (16 kDa - 23 kDa) glycoproteins on ejaculated boar spermatozoa have been shown to have high affinity for homologous zona pellucida glycoproteins (ZPGPs). These ZPGP binding proteins are derived from seminal plasma as shown by their absence from epididymal spermatozoa and their presence in seminal plasma as identified by N-terminal amino acid sequence analysis. They bind to ZPGPs by a polysulphate recognition mechanism similar to that found for proacrosin-ZPGP interactions. The haemagglutination activity of boar seminal plasma is also associated with these low Mr glycoproteins. It is suggested that they play a role in regulating the rate of sperm capacitation and survival in the female reproductive tract. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330115
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    Plant tissue culture manual: Fundamentals and applications, edited by K. Lindsey, 1991, Kluwer Academic Publishers, Dordrecht, The Netherlands, expandable, $76.50 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 116-116 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330118
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  • 141
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    Research proposals: A guide to success, by Thomas E. Ogden, 1991, Raven Press, New York, 397 pp, $39 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 116-116 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330119
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  • 142
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    Developmental regulation ofan snRNP core protein epitope during pig embryogenesis and after nuclear transfer for cloning (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 119-123 
    Details
    ISSN: 1040-452X
    Keywords: Porcine ; -Amanitin ; Immunoreactivity ; Monoclonal antibody ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The appearance and stabilization of a core protein epitope of the snRNP is developmentally regulated during pig embryogenesis. The epitope recognized by the monoclonal antibody Y12 is present in the germinal vesicle of mature ooocytes and interphase nuclei of late 4-cell stage (24 to 30 hours post cleavage to the 4-cell stage) to blastocyst stage embryos. There was no antibody iocalization within pronuclei, or nuclei of 2-cell or early 4-cell stage embryos. Zygotes or 2-cell stage embryos cultured in the presence of α-amanitin to the late 4-cell stage showed no immunoreactivity, whereas control embryos had immunoreactivity. Thus antibody localization was correlated with RNA synthesis and RNA processing that begins by 24 hours post cleavage to the 4-cell stage. A final experiment showed no detectable immunoreactivity in 16-cell stage nuclei that had been transferred to enucleated activated meiotic metaphase II oocytes. Since immunoreactivity is associated with active RNA synthesis and RNA processing, it suggests that the 16-cell stage nucleus, which is RNA synthetically active, does not process RNA after nuclear transfer to an enucleated activated meiotic metaphase II oocyte. © 1992 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330202
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  • 143
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    A freezing and thawing method of hamster oocytes designed for both the penetration test and chromosome assay of human spermatozoa (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 202-209 
    Details
    ISSN: 1040-452X
    Keywords: Cryopreservation ; Interspecific fertilization ; Chromosome analysis ; Penetration test ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Superovulated hamster oocytes were cryopreserved and thawed according to our carefully designed procedures. More than 90% (92 ± 4%) of oocytes survived freezing and thawing. They were proven to be well conserved, showing excellent performance comparable to freshly ovulated oocytes in the human sperm penetration test (proportion of penetrated ova: 94.7% vs. 93.6%) and human sperm chromosome analysis (proportion of metaphasic ova: 81.8% vs. 83.6%). There was no statistically significant difference in the incidences of sperm chromosome aberrations between assays using fresh and frozen-thawed oocytes. In addition, there was no statistically significant increase of aberrations in female pronuclear (hamster) chromosomes. This freezing-thawing method was found to be reliable, yielding viable hamster oocytes of high quality. © 1992 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330213
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    Vitrification of mouse oocytes using short cryoprotectant exposure: Effects of varying exposure times on survival (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 210-214 
    Details
    ISSN: 1040-452X
    Keywords: Oocytes cryopreservation ; Vitrification ; Mouse ; Minimal cryoprotectant exposure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effects on oocyte viability of varying the duration of exposure to cryoprotectants before rapid cooling to - 196°C were examined, using the vitrification protocol of Nakagata. A very short exposure (15 sec) was found to be optimal, resulting in an overall rate of development from vitrified oocytes to hatching blastocysts of 31.8%. Very high rates of survival (77-89%) of oocytes exposed to the cryoprotectant media, but without the vitrification, together with extreme variability in results between straws in the vitrified groups, suggest that losses in viability during vitrification may result from ice damage during devitrification of the medium. (c) 1992 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330214
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  • 145
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    Okadaic acid and p13suc1 modulate the reinitiation of meiosis in mouse oocytes (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 287-296 
    Details
    ISSN: 1040-452X
    Keywords: Cell cycle regulation ; Spindle formation ; M phase-promoting factor ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Short-term exposure to okadaic acid (OA), a specific inhibitor of protein phosphatases 1 and 2A, induced resumpton of meiosis, including metaphase spindle formation, in mouse oocytes treated with a phosphodiesterase inhibitor, while long incubations with OA arrested oocyte maturation at a step prior to spindle formation. To explore the basis for this difference, the overall patterns of protein synthesis and phosphorylation and the production of tissue-type plasminogen activator (tPA), the synthesis of which is induced after germinal vesicle breakdown (GVBD), were analyzed under various OA treatments. Short-term exposure to OA led to tPA production and did not greatly affect the maturation-associated changes in protein phosphorylation. By contrast, a long application of OA did not result in tPA production and induced more marked changes in protein phosphorylation.Microinjection into prophase oocytes of the the product of the fission yeast gene p13suc1, known to inhibit p34cdc2 kinase activation and/or activity, prevented meiotic reinitiation. This effect was overcome by microinjection of OA, at concentrations higher than those required for induction of maturation in the absence of p13suc1. These observations suggest that inhibition of phosphatase 1 or 2A or both triggers meiotic resumption by acting at the same site or at a site proximal to the p13suc1-sensitive step of cdc2 kinase activation. © 1992 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330309
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  • 146
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    In vitro fertilization, development, and implantation after exposure of mature mouse oocytes to visible light (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 297-302 
    Details
    ISSN: 1040-452X
    Keywords: Light exposure ; Implantation rate ; IVF ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mature mouse oocytes were exposed prior to in vitro fertilization to visible light during 1, 2, or 4 hr at an intensity of 4,000 lux. Compared to controls cultured under identical conditions but protected from light, exposed eggs did not show any significant modification of cleavage speed are rate. After transfer of blastocysts obtained in vitro in uteri of pseudopregnant females, the implantation rate and the proportion of normal fetuses were not found to be different in relation to preliminary light exposure of oocytes fertilized and cultured in vitro. © 1992 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330310
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  • 147
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    Characterization of male meiotic germ cell-specific antigen (Meg 1) by monoclonal antibody TRA 369 in mice (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 307-312 
    Details
    ISSN: 1040-452X
    Keywords: Testis ; mAb ; Pachytene spermatocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have identified a male meiotic germ cell-specific antigen (Meg 1) with monoclonal antibody (mAb) TRA 369 in mice. The Meg 1 antigen was strongly expressed in specific steps of meiotic germ cells from pachytene spermatocyte to early spermatid, and not in other germ cells or somatic cells. Immunohistochemical examination revealed that the antigen was localized to the cytoplasm and was not distributed in the nucleus or on the cell surface. This antigen was demonstrated to have a molecular weight of 93 kDa and an isoelectric point of 5.2 by Western blotting. This molecule was first detected in the testis of 13-day-old mouse when pachytene spermatocytes first appeared. Thus this is a differentiation-specific antigen in male meiotic germ cells, and mAb TRA 369 is a useful tool to study the regulation of germ cell differentiation and to define germ cell development in a molecular level. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330312
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  • 148
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    Biosynthesis of prostaglandins by human spermatozoa in vitro and their role in acrosome reaction and fertilization (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 303-306 
    Details
    ISSN: 1040-452X
    Keywords: Arachidonic acid ; Calcium ionophores ; Cyclooxygenase ; Cyclooxygenase inhibitors ; Lipoxygenase products ; Phospholipase A2 ; Thromboxanes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Five homogenates of human sperm cells were separately incubated with [14C]arachidonic acid in the presence of reduced glutathione, L-tryptophan, and haematin as cofactors. The cyclooxygenase products of archidonic acid metabolism were extracted, separated, and measuréd for their radioactivity. The rate of formation of prostaglandin (PG)D2, PGE2, PGF2α, 6-keto PGF1α, and thromboxane (TX)B2 were 18.0 ± 1.11, 10.9 ± 0.68, 5.8 ± 0.21, 3.9 ± 0.13 and 6.6 ± 0.52 pmol/106 cells/min, respectively. These results are discussed in relation to the hypothesis that cyclooxygenase metabolites of certain polyunsaturated fatty acids play an important part in the sperm acrosome reaction and fertilization. © 1992 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330311
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  • 149
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    Adsorption of oviductal fluid proteins by the bovine sperm membrane during in vitro capacitation (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 313-323 
    Details
    ISSN: 1040-452X
    Keywords: Oviduct ; Sperm membrane ; Proteins ; Capacitation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: 125I-labeled oviductal fluid (ODF) proteins and antiserum to ODF were used to determine whether ODF proteins associate with the sperm membrane during in vitro capacitation. Luteal and nonluteal pools of ODF were obtained from oviduct catheters during the estrous cycle. Washed sperm (50 × 106 sperm/ml) were incubated up to 4 h in a protein-free modified Tyrode's medium (MTM), or MTM supplemented with 40% ODF, or 0.5 ng 125I-labeled ODF proteins. Solubilized sperm membrane proteins and incubatin media containing ODF proteins were separated by gel electrophoresis. Membranes isolated from bovine sperm previously incubated with ODF, absorbed five 125I-proteins: A doublet at 85-95 kDa, and others at 24, 34, 53, and 66 kDa. The amount of 66 kDA 125I-protein associated with the sperm decreased during the incubation, whereas the amount of 85 to 95-kDa protein did not. Western blot analyses also detected the presence of ODF proteins (53, 66, 85-95, and 116 kDa) in solubilized membranes from sperm incubated in ODF. The 85 to 95-kDa protein in ODF decreased in ODF. The 85 to 95kDa protein in ODF decreased in apparent molecular weight by 5 kDa when associated with the sperm membrane. At 53 kDa ODF proteins which associated with sperm were transformed from two to three separate proteins. These studies indicate that the surface of sperm is modified by adsorption of ODF proteins ot the membrane during in vitro capacitation. (c) 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330313
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  • 150
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    Medium temperature epoxy resin for immunocytochemistry: Quetol 651 with water (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 274-280 
    Details
    ISSN: 1059-910X
    Keywords: Epoxy resin ; Acrylate and methacrylate resins ; Protein A-Gold ; Stereology ; Labeling intensity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The addition of 1% water to the epoxy resin Quetol increased the labeling intensity of the sample. The significant decrease of the curing temperature of the epoxy resin may assist in preservation of antigens. Water may also reduce the cross-linkage of the resin allowing more antigen to be available to the antibodies. The modified Quetol resin is an option for use in immunocytochemistry studies.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200307
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  • 151
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    Atypical cells in the normal guinea pig organ of Corti as revealed by micromanipuiation in SEM (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 288-297 
    Details
    ISSN: 1059-910X
    Keywords: SEM ; TEM ; Guinea pig ; Cochlea ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Inner ear tissue of the normal guinea pig was conductively stained (OTOTO-method) for SEM investigations. The Hensen's cells of the organ of Corti were removed using a micromanipulator inside the SEM. By this method atypical bodies of sensory and supporting cells were revealed in the apical turns of the cochlea. Atypical sensory cells showed great variations in size and shape. Several had no contact to Deiter's cells and no or only one nerve supply at their basal end. Atypical Deiter's cells showed alterations in shape and in the form of their phalangeal processes.Additionally altered parts of the organ of Corti were isolated by micromanipulation and embedded for correlative TEM-investigations.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200309
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    Preparation of individual electrically and video-recorded eggs for integrated temporal and electron microscopic analyses (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 298-304 
    Details
    ISSN: 1059-910X
    Keywords: Fertilization ; Sperm-egg interaction ; Gamete fusion ; Egg activation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: A method for correlative studies of early fertilization events that integrates techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy is described. A key feature of the method is its ability to identify the fertilizing sperm and to record the moment of egg excitation. Since the site of gamete interaction is recognizable throughout all stages of preparation, difficulties associated with locating the site of fertilization and determining specimen orientation for microtomy and electron microscopic examination are eliminated. Virtually all samples yield useful information. An example of interacting gametes fixed 4 sec after initiation of the fertilization potential and serial sectioned is described. The method is applicable to systems other than fertilizing eggs when functional, temporal, and spatial relationships of individual cells need to be correlated with changes in ultrastructure.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200310
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    Intercellular junctions in embryonic chick cardiac muscle revealed by rapid freezing and freeze-substitution (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 305-313 
    Details
    ISSN: 1059-910X
    Keywords: Cryofixation ; Development ; Fasciae adherentes ; Desmosomes ; Myocardium ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Using the method of rapid freezing and freeze-substitution, the embryonic chick cardiac muscle was investigated by transmission electron microscopy. Initially, the intercellular junctional complexes (fasciae adherentes and desmosomes) were formed in close proximity to each other along a nearly straight line. Subsequently, the separation of fasciae from desmosomes took place to form intercalated discs. The cell membranes of fasciae adherentes were reinforced with highly interwoven fine fibrils at which myofibrils terminated. The intercellular space of fasciae was bridged with fine fibrillar structures seemingly connected by a thin line at their middle portions. In the intercellular space of desmosomes, central lamina and traversing filaments were clearly observed. The outer and inner leaflets of the desmosomal plasmalemma were asymmetrically differentiated; the outer leaflet was thinner than the inner leaflet. On the inner side of the cell membrane, an electron-lucent layer and a dense desmosomal plaque were observed. The latter structure had protrusions with less electron density towards the cytoplasmic side. Further inside, a meshwork of fine fibrils was seen along and toward which bundles of intermediate filaments ran. The results obtained with freeze-substitution appeared to provide more information than those with thin sections after conventional fixation or with replicas of chemically fixed/glycerinated or physically fixed/deep-etched materials.
    Additional Material: 13 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200311
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    Ultrastructural distribution of the M form of creatine phosphokinase in human muscle by immunogold labeling (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 281-287 
    Details
    ISSN: 1059-910X
    Keywords: Creatine ; Creatine phosphokinase ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Creatine phosphokinase regenerates ATP from ADP using creatine phosphate. Isoenzymes of creatine phosphokinase are bound to certain cellular structures or are compartmentalized in areas of the cell, and this has been used as a basis for defining the role of these isoenzymes in energy metabolism. The M isoenzyme of creatine phosphokinase has been morphologically associated with the M-line of striated muscle in many species. In this present study the ultrastructural distribution and the relative concentration of the M form of creatine phosphokinase in human muscle tissue was determined using immunogold and electron microscopy. The M-line of the sarcomere, comprising only 3 - 4% of the sarcomere area, was found to contain over 20% of the total M isoenzyme signal of the entire sarcomere. This technique represents a quantitative, ultrastructural method to study the subcellular distribution of this isoenzyme. These data suggest that localized concentrations of M-CPK may be important for normal energy metabolism, and may also serve as a foundation for a better understanding of the relationship between abnormal creatine metabolism and the pathogenesis of neuromuscular disease.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200308
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    Electron energy loss spectrometers, by Harald Ibach. Springer Series in Optical Sciences Volume 63. Springer-Verlag, 1991, 178 pp, $59 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 314-314 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200312
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    Some discrepancies in muscle sarcomere length measurements on sections micrographed in the transmission electron microscope (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 315-316 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200313
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992) 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200401
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  • 158
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    Technique of reflection electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 318-332 
    Details
    ISSN: 1059-910X
    Keywords: RHEED ; Surface steps ; REM ; Surface defects ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Details of the technique of reflection electron microscopy (REM) are described. Step by step instruction is given on how to do it on an ordinary electron microscope. Also given are some specimen preparation techniques and strategy of REM investigation.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200403
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    Bloch wave treatment of symmetry and multiple beam cases in reflection high energy electron diffraction and reflection electron microscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 360-370 
    Details
    ISSN: 1059-910X
    Keywords: RHEED ; Bloch waves ; Green function ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Bloch wave equations for the multiple beam cases in reflection high energy electron diffraction (RHEED) are derived from the integral equation by forward- and back-scattering Green function operators. A linearization is achieved through separation in a forward- and a back-scattering component for each beam. This leads to a set of fundamental equations similar to the transmission case, but with a non-Hermitian matrix, and the beams may be entered as either forward-, back-scattered, or both. The number of beams needed to be included in RHEED calculations is thus reduced, and so are the computing time and computer space required. The systematic row case, corresponding to reflections from planes parallel to the crystal surface, is treated in detail and illustrated by calculations of dispersion surfaces and rocking curves for Au(001). Symmetry relations for the systematic row and between reciprocal rows are discussed and illustrated.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200407
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  • 160
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    Developments in the dynamical theory of high energy electron reflection (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 371-389 
    Details
    ISSN: 1059-910X
    Keywords: Bloch wave method ; Crystal surfaces ; Multislice ; Surface science ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: High energy electron reflection (HEER) is an important technique in surface science and uses the information carried by high energy electrons reflected from surfaces to study surface structures and surface electronic states. With the development of reflection high energy electron diffraction (RHEED), high energy electron microscopy (REM), and high energy electron energy loss spectroscopy (EEL) in surface science, the usefulness of HEER has been widely recognized and demonstrated. However, a stationary dynamical solution for an arbitrary surface for HEER has not been obtained yet.In this paper, some developments in understanding the dynamical theory of HEER, particularly in recent years, are reviewed: 1The introduction of the concept of current flow for a semi-infinite crystal model has removed the confusion around the wave points in the “band gap”.2The consistency between the Bloch wave and multislice in the Bragg case has verified the validity of the argument of current flow and led to the emergence of the BMCR method (Bloch wave + Multislice Combined for Reflection).3The failure of the Bloch Wave-Only solution (the BWO solution) on Au (110) surfaces in the Bragg case revealed by the BMCR method implies that previous BWO calculations in the Bragg case might be at fault.4The 2-D dependence of the electron wave fields and Picard iteration-like character of multislice calculation in the Bragg case has led to the emergence of an Edge Patching method in Multislice-mode-Only (the EPMO method). The new method yields an infinitely convergent stationary dynamical solution for an arbitrary surface.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200408
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  • 161
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    Reflection electron energy-loss spectroscopy and imaging for surface studies in transmission electron microscopes (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 390-405 
    Details
    ISSN: 1059-910X
    Keywords: Reflection electron microscopy ; Secondary electron imaging ; Field emission gun ; In situ REM ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: A review is given on the techniques and applications of high-energy reflection electron energy-loss spectroscopy (REELS) and reflection electron microscopy (REM) for surface studies in scanning transmission electron microscopes (STEM) and conventional transmission electron microscopes (TEM). A diffraction method is introduced to identify a surface orientation in the geometry of REM. The surface dielectric response theory is presented and applied for studying α-alumina surfaces. Domains of the α-alumina (012) surface initially terminated with oxygen can be reduced by an intense electron beam to produce Al metal; the resistance to beam damage of surface domains initially terminated with Al+3 ions is attributed to the screening effect of adsorbed oxygen. Surface energy-loss near-edge structure (ELNES), extended energy-loss fine structure (EXELFS), and microanalysis using REELS are illustrated based on the studies of TiO2 and MgO. Effects of surface resonances (or channeling) on the REELS signal-to-background ratio are described. The REELS detection of a monolayer of oxygen adsorption on diamond (111) surfaces is reported.It is shown that phase contrast REM image content can be significantly increased with the use of a field emission gun (FEG). Phase contrast effects close to the core of a screw dislocation are discussed and the associated Fresnel fringes around a surface step are observed. Finally, an in situ REM experiment is described for studying atomic desorption and diffusion processes on α-alumina surfaces at temperatures of 1,300 - 1,400°C.
    Additional Material: 16 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200409
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    Observation of atomic steps on single crystal surfaces by a commercial scanning electron microscope (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 406-412 
    Details
    ISSN: 1059-910X
    Keywords: REM ; Contrast mechanism ; Imaging technique ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Atomic steps on (111) and (100) crystal surfaces of Pt were observed using a commercial scanning electron microscope (SEM) in secondary electron mode. By comparing the SEM images and those by reflection electron microscopy (REM), the observed contrast was confirmed to be that from atomic steps on crystal surfaces. The contrast mechanism is briefly discussed. One application of this imaging technique is also shown.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200410
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  • 163
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    Observation of double line contrast in surface imaging (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 413-425 
    Details
    ISSN: 1059-910X
    Keywords: REM ; RHEED ; Surface resonance condition ; Contrast splitting ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The double line contrast of a single-atom height step observed in surface imaging for a single crystal in reflection electron microscopy is studied under a variety of experimental conditions. It is suggested that this abnormal contrast is directly associated with the dynamical electron diffraction process. The behavior of the double line contrast is closely related to the order of the Bragg reflected beam, and can be observed mostly under one of the two commonly cited resonance conditions. This phenomenon clearly reveals the differences in the surface imaging for various resonance conditions.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070200411
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  • 164
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    The ultrstructure of neuronal-pinealocytic interconnections in the monkey pineal (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 124-135 
    Details
    ISSN: 1059-910X
    Keywords: Pinealocyte ; Pineal-neuron ; Synapses ; Ribbon synapse ; Innervation ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Recent ultrastructural studies of neuronal-pinealocytic interconnections in the monkey pineal are reviewed. The pinealocytes in the adult monkey show almost all of the cytological specializations known in subprimate mammals. Adjacent pinealocytes are functionally coupled through ribbon synapses on cell bodies and gap junctions on cell bodies and cell processes. The pinealocytes receive direct synaptic contacts of nerve fibers with cholinergic terminal morphology. Nerve cells restricted to the central portion of the pineal receive synaptic contacts with more than three different morphologically defined types of nerve terminals. In addition to nerve terminals containing small clear vesicles or vesicles of pleomorphic morphology, a pinealocyte's terminal process containing the synaptic ribbon forms a true synaptic contact on the nerve cell body. The diversity of synapses on these nerve cells strongly suggests multiple origins of these neurons rather than a single peripheral parasympathetic origin. The possible involvement of pineal neurons in an intrinsic circuit that regulates the function of pinealocytes and integrates the neural input from the central as well as the peripheral nervous systems is discussed.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210205
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  • 165
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    The ultrastructure of mammalian pinealocytes: A systematic investigation (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 85-115 
    Details
    ISSN: 1059-910X
    Keywords: Bats ; Chiroptera ; Pinealocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Pinealocytes are not only the principal cellular components of the pineal gland, but they are also the principal synthetic machinery of this enigmatical gland with highly diverse and often questionable empyreal roles assigned to it. Ultrastructural descriptions of pinealocytes belonging to some 70 species of mammals (a mere 2% or less of the over 4,200 mammalian species) have been summarized from the available literature with new observations on 12 species of chiropterans. Space limitation precluded any treatment of the supporting glia, neural elements, and the perivascular spaces. A detailed table lists nearly all mammalian species whose pineal ultrastructure has been investigated. Blanks in this table point to the necessity of studies on those particular groups. A tabular listing of unusual structures reported within the pinealocyte cytoplasm points out the impending experimental work on these species. Such studies using the latest techniques might provide clearer insights into the functional role of the pineal gland as an important and integral component of the neuroendocrine axis. Whereas sufficient structural information now exists on cytoplasmic organelles such as synaptic ribbons and spherules, annulate lamellae, subsurface cisterns, and the several types of synaptic arrangements seen in relation to the pinealocyte soma and its processes, the functional role of these structures in pineal synthetic processes remains to be elucidated.
    Additional Material: 19 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210203
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  • 166
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    The thickness determination of organic crystals under low dose conditions using electron energy loss spectroscopy (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 166-170 
    Details
    ISSN: 1059-910X
    Keywords: Protein crystals ; Crystal thickness ; Paraffin crystals ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In the 3-dimensional (3-D) reconstruction of protein crystals with variable thicknesses the electron images and diffraction patterns can only be merged if the crystal thickness is known. Measurement of the thickness using the ratio of the number of inelastically scattered electrons to the number of electrons in the zero loss peak can be accomplished with parallel electron energy loss spectrometry (PEELS). A theoretical analysis of the accuracy of the technique on paraffin crystals of different thicknesses is presented. Our experimental studies with paraffin crystals show the feasibility of measuring a single layer of 47 Å with good accuracy under low dose and low temperature conditions. A simple experimental apparatus is proposed to obtain thicknesses from small regions of unstained protein crystals prior to collecting the 3-D data sets from the unexposed area of the same crystal.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210208
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    Experimental morphology of insect olfaction: Tracer studies, x-ray microanalysis, autoradiography, and immunocytochemistry with silkmoth antennae (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 336-350 
    Details
    ISSN: 1059-910X
    Keywords: Bombyx mori ; Antheraea polyphemus ; Olfactory sensilla ; Cryofixation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The general morphology and methodological peculiarities of insect sensilla are briefly reviewed. The stimulus conducting pore-tubule systems of pheromone-sensitive sensilla of the silkmoths Bombyx mori and Antheraea polyphemus are described. Lipophilic tracers readily enter the hair lumen, while hydrophilic tracers do so only after prolonged extraction with lipid solvents and/or pronase. X-ray microanalysis demonstrates a high potassium content of the sensillum lymph; calcium was only found in the haemolymph above detection limit. Auxiliary cells rapidly take up radioactive leucine administered via the haemolymph. Antibodies against pheromone-binding protein of Antheraea polyphemus label the sensillum lymph of sensilla trichodea, but not of sensilla basiconica in A. polyphemus as well as in B. mori. The cytoplasm of auxiliary cells of the sensilla trichodea is also labelled. The results are discussed in context with present hypotheses on the role of sensillum lymph in stimulus transport and inactivation. © 1992 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070220404
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  • 168
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    Fine structure of a developing insect olfactory organ: Morphogenesis of the silkmoth antenna (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 351-371 
    Details
    ISSN: 1059-910X
    Keywords: Antheraea polyphemus ; Olfactory sensilla ; Differential mitoses ; Epidermal feet ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The olfactory organ of the silkmoth Antheraea polyhemus is the feathered antenna which carries about 70,000 olfactory sensilla in the male. It develops within 3 weeks from a leaf-shaped epidermal sac by means of segmental primary and secondary indentations which proceed from the periphery towards the centerline. During the first day post-apolysis, the antennal epidermis differentiates into segmentally arranged, alternating sensillogenic and non-sensillogenic regions. Within the first 2 days post-apolysis, the anlagen of olfactory sensilla arise from electron-dense mother cells in the sensillogenic epidermis. The axons of the developing sensilla begin to form the primary innervation pattern during the second day. The sensilla develop approximately within the first 10 days to their final shape, while the indentations are completed during the same period of time. The indentations are most probably driven by long basal extensions of epidermal cells, the epidermal feet. Primary indentations follow the course of segmentally arranged tracheal bundles and form the segments of the antenna. The secondary indentations follow the course of the primary segmental nerves which are reconstructed by this process. During the remaining time of development, the cuticle of the antenna and the sensory hairs is secreted by the epidermal and the hair-forming cells. © 1992 Wiley-Liss, Inc.
    Additional Material: 21 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070220405
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    Proceedings of the tenth annual meeting of the florida society for electron microscopy held at Crystal River, Florida, March 4-6, 1992 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 403-406 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070220409
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    Computer simulation of electron microscope diffraction and images, edited by W. Krakow and M. O'Keefe. The Minerals, Metals, and Materials Society, Warrendale, Pennsylvania, 1989, 275 pp, $50.00 (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 200-200 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070230209
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  • 171
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    Immunocytochemical localization of cell adhesion molecules in the developing and mature olfactory system (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 157-172 
    Details
    ISSN: 1059-910X
    Keywords: N-CAM ; L1 ; AMOG ; J1 ; L2-HNK-1 ; Olfactory system ; Development ; Immunocytochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The localization of Ca++-independent cell adhesion molecules (CAMS) in the developing and mature olfactory epithelium and bulb is reviewed. The CAMs included in this article are the neural cell adhesion molecule (N-CAM), the 180 kD component of N-CAM (N-CAM 180), the embryonic form of N-CAM (E-N-CAM), L1 glycoproteins, J1 glycoproteins, and the adhesion molecule on glia (AMOG). In addition, the expression of the L2-HNK-1 carbohydrate epitope, shared by N-CAM, L1, J1 and myelin-associated glycoprotein (MAG) in the adult olfactory epithelium and bulb has also been documented. For the localization of these molecules at the light and electron microscopic levels, immunocytochemical techniques were used and are described in detail.During development and organogenesis, the olfactory system exhibits a pattern of CAM expression similar to the general pattern described for the developing nervous system. In the adult olfactory system, however, a significant retention of CAMs characteristic for developmental and morphogenetic processes, such as E-N-CAM, AMOG, as well as the high molecular weight components of J1 glycoproteins, can be observed. The retention of these embryonic features are most likely associated with the cell turnover and high plasticity of this system. Moreover, the predominance of N-CAM 180 with respect to other components of N-CAM, as well as the absence of the L2/HNK-1 carbohydrate epitope, are also particular traits of the primary olfactory system which could be associated with its exceptional properties. © 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230206
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    Fine structure of the vomeronasal and septal olfactory epithelia and of glandular structures (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 86-97 
    Details
    ISSN: 1059-910X
    Keywords: Accessory olfactory ; Nasal glands ; Odorant binding protein ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The vomeronasal and septal olfactory organs are two neurosensory structures in the mammalian nasal septum which are poorly understood relative to the main olfactory system. The vomeronasal organ is a paired, blind-ending tubular structure that opens rostrally into the nasal cavity in some species and into the incisive ducts in others. When present in mammals, the septal olfactory organ is an island of olfactory mucosa positioned such that it is in the primary air pathway in the caudal portion of the nasal cavity. Mammalian nasal glands, with a diverse histochemical and ultrastructural morphology, secrete a variety of substances onto the mucosal surface. One of these substances, odorant binding protein, localized in bovine nasal glands and lateral nasal glands of rodents may be important in the capture and conveyance of odorant molecules to olfactory receptors. The objectives of this paper are to present original data while reviewing the literature on the ultrastructure of vomeronasal and septal olfactory neuroepithelia, and of vomeronasal, bovine nasal, and lateral nasal glands. Nasal tissues from pigs, calves, and hamsters were prepared for electron microscopy. Neurosensory epithelia of the porcine vomeronasal organ and the hamster septal olfactory organ are similar to that described for the vomeronasal and septal olfactory organs of other mammals. Bovine nasal and rodent lateral nasal glands consist of subregions which differ morphologically; the most abundant acinar cell type in the bovine nasal gland contains lightly electron dense secretory granules while that of the rodent lateral nasal gland contains both small electron dense and large, electron lucent granules. The porcine vomeronasal gland contains numerous small, dense granules of a diverse morphology. © 1992 Wiley-Liss, Inc.
    Additional Material: 17 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230108
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    Masthead (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992) 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070230201
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    Ultrastructural histopathology of human olfactory dysfunction (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 103-110 
    Details
    ISSN: 1059-910X
    Keywords: Olfaction ; Anosmia ; Pathology ; Nose ; Smell ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: This paper presents electron-microscopic observations on biopsies of the olfactory mucosae of several classes of patients with smell disorders: 1) patients with loss of smell function following head injury (post-traumatic anosmics or hyposmics); 2) patients with loss of smell function following severe head colds and/or sinus infections (post-viral olfactory dysfunction, or PVOD); and 3) patients that have lacked smell function since birth (congenital anosmics). Of these, the traumatic anosmics' olfactory epithelia were quite disorganized; the orderly arrangement of supporting cells, ciliated olfactory receptor neurons, microvillar cells, and basal cells was disrupted. Although many somata of ciliated olfactory receptors were present, few of their dendrites reached the epithelial surface. The few olfactory vesicles present usually lacked olfactory cilia. The postviral anosmics, too, had a greatly reduced number of intact ciliated olfactory receptor neurons, and most of those present were aciliate. The post-viral hyposmics had a larger population of intact, ciliated olfactory receptor cells. In the seven cases of congenital anosmia studied, no biopsies of olfactory epithelium were obtained, indicating the olfactory epithelium is either absent - or greatly reduced in area - in these individuals. © 1992 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230202
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    Fine structural aspects of secretion and extrinsic innervation in the olfactory mucosa (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 111-127 
    Details
    ISSN: 1059-910X
    Keywords: Bowman's glands ; Sustentacular cells ; Goblet cells ; Nerve terminalsa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The mucus at the surface of the olfactory mucosa constitutes the milieu in which perireceptor events associated with olfactory transduction occur. In this review, the ultrastructure of olfactory mucus and of the secretory cells that synthesize and secrete olfactory mucus in the vertebrate olfactory mucosa is described. Bowman's glands are present in the olfactory mucosa of all vertebrates except fish. They consist of acini, which may contain mucous or serous cells or both, and ducts that traverse the olfactory epithelium to deliver secretions to the epithelial surface. Sustentacular cells are present in the olfactory epithelium of all vertebrates. In fish, amphibia, reptiles, and birds, they are secretory; in mammals, they generally are considered to be “nonsecretory,” although they may participate in the regulation of the mucous composition through micropinocytotic secretion and uptake. Goblet cells occur in the olfactory epithelium of fish and secrete a mucous product.Secretion from Bowman's glands and vasomotor activity in the olfactory mucosa are regulated by neural elements extrinsic to the primary olfactory neurons. Nerve fibers described in early anatomical studies and characterized by immunohistochemical studies contain a variety of neuroactive peptides and have several targets within the olfactory mucosa. Ultrastructural studies of nerve terminals in the olfactory mucosa have demonstrated the presence of adrenergic, cholinergic and peptidergic input to glands, blood vessels, and melanocytes in the lamina propria and of peptidergic terminals in the olfactory epithelium. The neural origins of the extrinsic nerve fibers and terminals are the trigeminal, terminal, and autonomic systems. © 1992 Wiley-Liss, Inc.
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    Improved method for the preparation of TiN-coated WC-Co-based samples for cross-sectional AEM investigation (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 239-242 
    Details
    ISSN: 1059-910X
    Keywords: Braze alloys ; WC ; XTEM sample preparation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: An improved method for the preparation of cross-sectional thin foils of coated WC-Co samples for studies by analytical electron microscopy is described. A braze alloy is used to join the sections of the sample together and the resulting sample is stable during subsequent grinding, dimpling, and milling operations. Cross-sectional micrographs provide examples of the efficacy of this method. No microstructural alteration associated with the brazing operation was observed. © 1992 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070230307
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    Effect of crystal and beam tilt on simulated high-resolution TEM images of interfaces (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 230-238 
    Details
    ISSN: 1059-910X
    Keywords: High-resolution electron microscopy ; Twin boundaries ; Interphase boundaries ; Compositional order ; Reflex images ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The effects of crystal and beam tilt on high-resolution transmission electron microscope (HRTEM) images of planar coherent interfaces were investigated by multislice image simulations. It was found that a beam tilt of 0.5 Bragg angle (θB) was sufficient to introduce detrimental artifacts into most images of interfaces in crystals only 1/8ξ000 thick, while crystal tilt had a much smaller effect even for crystals 1ξ000 thick. Effects produced in HRTEM images of interfaces by crystal and beam tilt included the introduction of additional periodicities and loss of compositional detail across a boundary, translation of a boundary from its actual position, and apparent mismatch of atomic planes across a perfectly coherent interface. These results indicate that alignment of the electron beam parallel to the optic axis is critical for reliable HRTEM imaging of interfaces in materials. Techniques for obtaining accurate alignment are also discussed. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230306
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    Application of automatic image analysis for quantitative morphological studies of peroxisomes in rat liver in conjunction with cytochemical staining with 3-3′-diaminobenzidine and immunocytochemistry (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 271-282 
    Details
    ISSN: 1059-910X
    Keywords: Peroxisomes ; Morphometry ; Protein A-gold ; Hypolipidemic drugs ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: We describe the application of automatic image analysis for quantitative morphological studies of peroxisomes in rat liver. For automatic detection by light and electron microscopy peroxisomes must be stained with the alkaline DAB procedure for catalase. There is a good agreement between the results obtained by conventional morphometric techniques and by automatic image analysis of DAB-stained electron microscopic preparations. Moreover, the image analyzer may be used in conjunction with a light microscope for evaluation of semithin sections (1-0.25 μm), provided the section thickness factor is taken into consideration. This latter approach has proven highly efficient in estimation of peroxisome proliferation. The limitations of this method and the relevance of volume density as a reliable morphometric parameter for evaluation of peroxisome proliferation are discussed. In the second part of this study we present the application of image analysis for quantitation of alterations of individual peroxisomal enzyme proteins after treatment with bezafibrate in immunogold stained ultrathin sections. There is good agreement between the results of quantitative immunocytochemistry and Western (immuno) blot analysis of highly purified peroxisomal fractions. In our experience quantitative immunoelectron microscopy provides a versatile, highly sensitive, and efficient method for detection of modulations of various proteins in peroxisomes. Finally the limitations and prospects of quantitative immunocytochemistry for investigation of peroxisomal proteins are discussed. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210404
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    The microcomputer and image analysis in diagnostic pathology (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 292-299 
    Details
    ISSN: 1059-910X
    Keywords: Morphometry ; Histology ; Cytology ; Software ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: This paper presents a snapshot view of the influence and direction of microcomputer technology for image analysis techniques in diagnostic pathology.Microcomputers have had considerable impact in bringing image analysis to wider application. Semi-automated tracing techniques are a simple means of providing objective data and assist in a wide range of diagnostic problems. From the common theme of reducing subjectivity in diagnostic assessment, an extensive body of research has accrued. Some studies have addressed the need for quality control for reliable, routine application.Video digitizer cards bring digital image analysis within the reach of laboratory budgets, providing powerful tools for investigation of a wide range of cellular and tissue features. The use of staining procedures compatible with quantitative evaluation has become equally important. As well as assisting scene segmentation, cytochemical and immunochemical staining techniques relate the data to biological processes.With the present state of the art, practical use of microcomputer based image analysis is impaired by limitations of information extraction and specimen throughput. Recent advances in colour video imaging provide an extra dimension in the analysis of multi-spectral stains. Improvements will also be felt with predictable increase in speed of microprocessors, and with single chip devices which deliver video rate processing. If the full potential of this hardware is realized, high-speed, routine analysis becomes feasible. In addition, a microcomputer imaging system can play host to companion functions, such as image archiving and transmission.With this outlook, the use of microcomputers for image analysis in diagnostic pathology is certain to increase. However, it is the software in both design and concept which ultimately governs the performance which can be achieved. Progress may be made by structured software techniques, by application of mathematical principles, or by use of expert systems for data or image interpretation. © 1992 Wiley-Liss, Inc.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210406
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    Quantitative perimeter and area measurements of digital images (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 300-314 
    Details
    ISSN: 1059-910X
    Keywords: Digital perimeter ; Digital area ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Quantitative estimations of perimeter and area from digitized video images, and the application of these features in morphometry, are discussed. Estimations from manual tracings via interactive peripherals and from chain codes are addressed. Topics discussed are calibration, determination of vertical and horizontal pixel resolution, effects of tracing jitter, and for chain codes, the spatial quantization scheme representation of the digital contour. Finally, new perimeter estimators for 4-connected and 8-connected chain codes for non-unity pixel aspect ratio are presented with simulation results.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210407
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    Dynamics of golgi impregnation in neurons (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 264-274 
    Details
    ISSN: 1059-910X
    Keywords: CNS ; Light microscopy ; Electron microscopy ; Cerebral cortex ; Nerve cell ; Impregnation method ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: This paper describes the early stages of impregnation by the Golgi rapid method in sections and blocks of brain tissue. Aldehyde-fixed and potassium dichromate-treated sections of cerebral cortex were placed on glass slides and coverslipped. The dichromate solution was then replaced by a silver nitrate solution, and events taking place in the section were monitored and time-lapse recorded until the impregnation was interrupted and the sections subsequently prepared for electron microscopy. The tissue blocks, fixed and chromated in the same way, were placed into a silver nitrate solution for 30 min to 24 h and the progress of impregnation compared with the results obtained in the sections on the glass slides.Two basic modes of impregnation were observed, apparently in direct relation to the process of crystallization of silver chromate: crystals of silver chromate growing directly from the surface of the tissue into the nerve cell via its transected plasma membranes, and microcrystalline precipitate of silver chromate spreading into the nerve cell from nucleation centres dispersed in the tissue. The precipitate grows inside the cell as in a preformed channel until the cell has been filled. If the nucleation begins extracellularly, the precipitate extends into the narrow intercellular gaps. Electron microscopy showed that the crystalline precipitate consisted of multilamellar formations containing dense coalesced granules that did not cross plasma or endocellular membrane boundaries. © 1992 Wiley-Liss, Inc.
    Additional Material: 38 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230403
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    Techniques for converting golgi precipitate in CNS neurons into stable electron microscopic markers (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 275-288 
    Details
    ISSN: 1059-910X
    Keywords: Golgi-electron microscopy ; Gold substitution ; Chemical reduction ; Stabilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Direct electron microscopy of nervous tissue stained with the Golgi impregnation method is unsatisfactory because the cytoplasm of the cell bodies and processes of the impregnated neurons are completely filled with a compact precipitate of electron dense silver chromate. This precipitate entirely obscures the cytological details of the impregnated neurons. Because of its solidity and instability in aqueous solutions, the silver chromate is also a source of inconvenience during the preparation of the ultrathin sections.This review summarizes methods that have been developed with the aim of replacing the Golgi precipitate in CNS neurons with a more convenient electron dense material - for example, heavy metal salts or metallic particles. Conversion of the precipitate into a stable electron dense marker is done before the material is embedded for electron microscopy. The methods include lead, gold, and bromide substitution, treatment with ammonia, direct chemical reduction into metallic silver, and photoreduction of the silver chromate into silver through irradiation with ultraviolet light. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230404
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    Electron microscopy of Golgi-impregnated interneurons: Notes on the intrinsic connectivity of the cerebral cortex (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 289-305 
    Details
    ISSN: 1059-910X
    Keywords: Golgi-EM procedure ; Identified neurons ; Synapses ; Neuronal taxonomy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The Golgi-electron microscope technique has opened new avenues to explore the synaptic organization of the brain. In this article, we shall discuss basic methodological principles necessary to analyze axonal arborizations with this combined technique. To illustrate the applications of the method, we shall review the forms and distribution of the synapses in which the axonal arborizations of local cortical interneurons engage. © 1992 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230405
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    Determining the neuronal connectivity of Golgi-impregnated neurons: Ultrastructural assessment of functional aspects (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 324-333 
    Details
    ISSN: 1059-910X
    Keywords: Golgi impregnation ; Golgi-electron microscopy ; Neuronal connectivity ; Neural network ; Synaptic connection ; Dendritic spine ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The combined light and electron microscopic analysis of Golgi-impregnated neural tissue is a potent tool for determining the connectivity of neural networks within the brain. In the experimental paradigms commonly applied in these studies, the Golgi-impregnated neurons are typically examined as the postsynaptic neuronal components. The structural characteristics and the pattern of distribution of their synaptic connections with other groups of identified neurons are analyzed. Due to the high power of resolution of the Golgi-electron microscopic technique, the ultrastructural analysis of Golgi-impregnated neurons can be expanded to elucidate activity-dependent structural alterations in their cytoarchitecture. These structural alterations can then be correlated under different physiological conditions with changes in the functional efficacy of the subcellular neuronal components. © 1992 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230407
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    Application of the Golgi/electron microscopy technique for cell identification in immunocytochemical, retrograde labeling, and developmental studies of hippocampal neurons (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 306-323 
    Details
    ISSN: 1059-910X
    Keywords: Section Golgi impregnation ; Cholinergic synapses ; Neuronal specificity ; Neural transplantation ; Slice culture ; Neuronal plasticity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In this study the Golgi/electron microscopy (EM) technique has been used for an analysis of the fine structure, specific synaptic connections, and differentiation of neurons in the hippocampus and fascia dentata of rodents. In a first series of experiments the specific synaptic contacts formed between cholinergic terminals and identified hippocampal neurons were studied. By means of a variant of the section Golgi impregnation procedure, Vibratome sections immunostained for choline acetyltransferase, the acetylcholine-synthesizing enzyme, were Golgi-impregnated in order to identify the target neurons of cholinergic terminals in the hippocampus. It could be shown with this combined approach that cholinergic septohippocampal fibers form a variety of synapses with different target structures of the Golgi-impregnated and gold-toned hippocampal neurons. In this report cholinergic synapses on the heads of small spines, the necks of large complex spines, dendritic shafts, and cell bodies of identified dentate granule cells are described. The variety of cholinergic synapses suggests that cholinergic transmission in the fascia dentata is a complex event.Next, the Golgi/EM technique was applied to Vibratome sections that contained retrogradely labeled neurons in the hilar region of the fascia dentata following horseradish peroxidase (HRP) injection into the contralateral hippocampus. With this combined approach some of the hilar cells projecting to the contralateral side were identified as mossy cells by the presence of retrogradely transported HRP in thin sections through these Golgi-impregnated and gold-toned neurons. Our findings suggest that the mossy cells are part of the commissural/associational system terminating in the inner molecular layer of the fascia dentata. They are mainly driven by hilar collaterals of granule cell axons that form giant synapses on their dendrites.Finally, the Golgi/EM procedure was used to study the differentiation and developmental plasticity of hippocampal and dentate neurons in transplants and slice cultures of hippocampus. Under both experimental conditions, the differentiating neurons are deprived of their normal laminated afferent innervation but develop their major cell-specific characteristics including a large number of postsynaptic structures (spines). As revealed in thin sections of gold-toned identified cells, all these spines formed synapses with presynaptic boutons suggesting sprouting of the transplanted and cultured neurons, respectively.Altogether, the present report demonstrates the usefulness of the Golgi/EM technique, particularly of the section impregnation procedure, for a variety of studies requiring the identification of individual neurons at the ultrastructural level. © 1992 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230406
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    Expression of estrogen receptor gene in mouse oocyte and during embryogenesis (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 407-412 
    Details
    ISSN: 1040-452X
    Keywords: mRNA ; Embryo ; Oocyte maturation ; Cumulus-oocyte complex ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Estrogen is required for oocyte maturation and embryonic development in vivo; however, the mechanism involved is not clear. Since the effect of estrogen is mediated through the estrogen receptor (ER), we examined the ontogeny and expression of the ER gene in mouse oocytes and embryos of various gestational stages using the highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Total RNA, extracted from 40 ovulated oocytes, 2-cell embryos, morulae, and blastocysts, was reverse transcribed into cDNA. A pair of primers flanking the 453-bp region encoding the hormone-binding domain of ER was used for 30 cycles of PCR. The identity of the amplified product was confirmed by sizing and Southern blot hybridization. The results indicated that ER gene is expressed in unfertilized oocytes and cumulus-oocyte complexes. The amount of ER mRNA decreases in 2-cell embryos, coincident with degradation of maternal mRNA. No ER transcript can be detected in the morulae or blastocyst stage when the embryonic genome has been activated. Postimplantation embryos do not contain detectable ER mRNA until gestation day 8. The levels of ER mRNA increase from day 10 to day 18 of gestation. These data suggest that estrogen, secreted by granulosa cells, may directly influence oocyte growth and maturation in vivo. Since estrogen is known to stimulate the production of growth factors in mouse uteri, the absence of ER mRNA in periimplantation embryos suggests that the effects of estrogen on early embryogenesis may be indirect, i.e., through estrogen-regulated growth-promoting factors produced by the reproductive tract. In mid- and late-post-implantation embryos which contain ER mRNA, estrogen may affect embryonic development through the receptor-mediated mechanisms. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/mrd.1080330406
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    Fertilization envelope in diapause eggs of Pontella mediterranea (crustacea, copepoda) (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 463-469 
    Details
    ISSN: 1040-452X
    Keywords: Cortical reaction ; Diapause ; Copepods ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The sequence and timing of morphological changes during envelope formation was followed in diapause eggs of Pontella mediterranea (Crustacea, Copepoda). The multilayer coat enveloping these eggs resulted from the exocytosis of 4 types of cortical vesicles that sequentially released their contents in the perivitelline space. These included small high-density vesicles (hDV) with electron-dense material, vesicles (V) with dense ring granules and a uniform matrix contained within the same compartment, large high-density (HDV) vesicles, and large moderately dense (MDV) vesicles. All of these cortical vesicles were present in newly spawned, fertilized eggs. Their exocytosis resulted from egg activation. One of these cortical vesicles (V) was similar in morphology to the intracisternal granules precursors of endogenous yolk. Intracisternal granules, characteristic of previtellogenic oocytes of many crustaceans, were present in previtellogenic oocytes of P. mediterranea but disappeared in later stages of oocyte development once yolk formation was completed. We discuss the role of cortical vesicles in the formation of the complex extracellar coat enveloping copepod diapause eggs. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/mrd.1080330413
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    Monoclonal antibody AG7 inhibits fertilization post sperm-zona binding (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 451-462 
    Details
    ISSN: 1040-452X
    Keywords: Sperm antigens ; Acrosome reaction ; Calcium influx ; Zona pellucida ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Monoclonal antibodies (mAbs) against sperm cells are currently being used in an effort to define spermatozoal antigens involved in the fertilization process. We have produced a number of anti-human sperm mAbs by immunization of female mice with the 100,000 × g supernatant of octylglycoside-solubilized washed human sperm. From a panel of mAbs, 1 antibody, AG7, was selected and characterized due to its fertilization-inhibiting characteristics. MAb AG7 defines a sperm acrosome antigen-1 (SAA-1) located in the acrosomal region of human sperm as evaluated by indirect immunofluorescence. Staining of life sperm cells indicated that the antigen is present on the sperm surface. SAA-1 was also found on sperm of several other mammalian species, implying evolutionary conservation of the antigen. SAA-1 was first observed on testicular sperm and can be followed through epididymal transit, ejaculation, and capacitation. When applied in a mouse in vitro fertilization assay, mAb AG7 inhibits fertilization by greater than 95%, and inhibition is dose dependent, with half-maximal inhibition at 0.8 μg/ml. The block to fertilization could not be attributed to sperm agglutination, inhibition of motility, interference with adhesion to the zona pellucida, or inhibition of fusion with the oocyte membrane. MAb AG7 was demonstrated to inhibit calcium influx in spermatozoa in vitro (measured using the fluorescent indicator fura 2), a prerequisite for the acrosome reaction. Initial biochemical characterization of the antigen suggests it is proteinlike in nature, with a molecular weight of approximately 220 kD. The results suggest that SAA-1, identified by mAb AG7, is a sperm antigen crucially involved in the fertilization process, possibly an atypical steriod receptor or ion channel located within the sperm plasma membrane. © 1992 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080330412
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    Human sperm proteins from testicular and epididymal origin that participate in fertilization: Modulation of sperm binding to zona-free hamster oocytes, using monoclonal antibodies (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 470-480 
    Details
    ISSN: 1040-452X
    Keywords: Sperm maturation ; Sperm differentiation ; Male infertility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In order to identify human sperm surface proteins involved in the gamete recognition process, mouse monoclonal antibodies were directed against human spermatozoa and screened with live spermatozoa by enzyme-linked immunosorbent assay (ELISA). Immunoperoxydase staining of human testis showed the early presence of four corresponding proteins on germinal cells, while six were detected primarily in testis fluid. The presence of 17 proteins was evidenced in the epididymis. Eight were detected with a decreasing gradient from the begining to the end of the organ, including vasa efferentia for three of them. The other nine were observed in only one defined segment, usually the caput epididymis, which was found to be the most active region. Comparison of spermatozoa patterns from testis, vasa efferentia, and the three regions of epididymis pointed out a progressive coating. By contrast, three antibodies displayed a migration of spermatozoa surface domains in the course of epididymal transit. Six antibodies were found to inhibit human spermatozoa adherence to zona-free hamster oocytes, while nine promoted it. Molecular weights of antigens corresponding to nine of the antibodies ranged from 11 to 215 kDa. No correlation could be established with previously described human proteins. These observations emphasize the role of epididymis in human sperm maturation. © 1992 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/mrd.1080330414
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    Expression of a gene encoding a rabbit sperm membrane protein in mammalian cells (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 9-13 
    Details
    ISSN: 1040-452X
    Keywords: Spermatogenesis ; Spermiogenesis ; Sperm tail antigen ; CHO cells ; Germ cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A general mammalian expression vector designated pSV2-EP was reconstructed by inserting an oligonucleotide fragment into pSV2-dhfr. This vector allowed insertion of cDNAs with EcoRI cohesive ends. The pSV2-EP contains a simian virus 40 (SV40) early promoter, origin for DNA replication, SV40 poly-A site, splicing site, an initiator ATG downstream from the promoter and an EcoRI site for the insertion of cDNA fragment screened from Àgt11 expression libraries. A recombinant plasmid (pSVRS-1) was constructed by inserting RSD-1, a cDNA encoding a rabbit sperm tail protein, into the EcoRI site of the pSV2-EP vector. Chinese hamster ovarian (CHO) dhfr-negative cells were contransformed with pSV2-dhfr and pSVRS-1 by the calcium phosphate method. In selective culture medium without thymidine and hypoxanthine, several cell lines were obtained containing mRNA and DNA that hybridized with RSD-1. One of these transformed cell lines stained intensely with anti-rSMP-B antibodies, demonstrating that the RSD-1 was expressed in the transformed CHO cells.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080310103
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    Effects of oxygen toxicity on early development of mouse embryos (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 28-33 
    Details
    ISSN: 1040-452X
    Keywords: Mouse embryo ; Superoxide dismutase ; Low-oxygen culture ; Two-cell block ; Oxygen radical ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To examine the effects of oxygen toxicity on embryonic development, mouse pronuclear embryos were cultured under low oxygen conditions with or without superoxide dismutase (SOD), and the blastulation rate was compared with that of embryos cultured under standard conditions. The blastulation rate of mouse pronuclear embryos cultured under standard conditions was only 1.5% (2/131). This rate was increased significantly, to 28.5% (43/151), when the embryos were cultured under low oxygen conditions; and to 31.0% (35/113) when SOD (500 μg/ml) was added to the medium under standard conditions; the rate was increased to 75.2% (115/153) when the embryos were cultured under low oxygen conditions in the presence of SOD. The minimum effective concentration of SOD in the culture medium was 50 μg/ml under conditions of 5% O2. The blastulation rate was significantly decreased after 1-hr exposure of pronuclear embryos to room atmospheric oxygen concentration (20% O2), and subsequent culture under 5% O2 with SOD did not result in an improved blastulation rate. Culture with SOD under 5% O2 promoted the development of two-cell stage embryos to the blastocyst stage. When two-cell stage embryos were collected 48 hr after hCG and cultured for 66 hr, their blastulation rate was similar to that of embryos collected from mice 114 hr after hCG. These results suggested that embryonic development in vitro is greatly affected by atmospheric oxygen throughout the early embryonic stages and that this harmful effect can be prevented by culturing embryos under low oxygen conditions and in the presence of SOD.
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    URL: http://dx.doi.org/10.1002/mrd.1080310106
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    A guanine nucleotide-binding regulatory protein in human sperm mediates acrosomal exocytosis induced by the human zona pellucida (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 78-86 
    Details
    ISSN: 1040-452X
    Keywords: G protein ; Pertussis toxin ; ADP-ribosylation ; Human sperm ; Acrosome reaction ; Zona pellucida ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Guanine nucleotide-binding regulatory proteins play key intermediary roles in regulating zona pellucida-mediated acrosomal exocytosis in mouse and bull sperm. Since human sperm possess a Gi-like protein and undergo the acrosome reaction in response to the human zona pellucida, we investigated whether this G protein plays a regulatory role in this exocytotic process. Zonae pellucidae isolated from eggs that had been inseminated but had shown no signs of fertilization after retrieval for in vitro fertilization and embryo transfer were pooled into groups of ≥50 in order to reduce variability in biological responses due to the possible presence of ZP that had undergone modifications associated with the polyspermy block. Acid-solubilized zonae pellucidae were incubated with capacitated sperm, and the sperm then assessed for the acrosome reaction using both the P. sativum agglutinin and chlortetracycline fluorescence assays; both assays gave similar results. Sperm incubated with solubilized zonae pellucidae at a final concentration of 2, 4, or 6 ZP/μl underwent acrosomal exocytosis to a similar extent as compared with A-23187. Sperm were incubated with 1 μg/ml pertussis toxin during capacitation to functionally inactivate the Gi-like protein. Pertussis toxin treatment of sperm did not affect sperm motility and the ability of the cells to bind to structurally intact zonae pellucidae. Pertussis toxin, however, completely inhibited the percentage acrosome reactions induced by solubilized zonae pellucidae. By contrast, the A-23187-induced acrosome reaction was insensitive to PT treatment. Pertussis toxin inhibition of the zona pellucida-induced acrosome reaction occurred in a concentration-dependent manner with maximal effects observed at 100 ng/ml PT. These data suggest that the pertussis toxin-sensitive Gi-like protein in human sperm plays an important regulatory role in the acrosome reaction induced by the human zona pellucida.
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    URL: http://dx.doi.org/10.1002/mrd.1080310114
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    Enhanced in vitro growth of murine fibroblast cells and preimplantation embryos cultured in medium supplemented with an amphipathic peptide (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 106-113 
    Details
    ISSN: 1040-452X
    Keywords: Embryo development ; Lytic peptide ; Growth factor ; Cecropin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Preliminary studies on the proliferative effects of lytic peptides were carried out using NIH 3T3 murine fibroblast cells and human lymphocytes. Cells were cultured in various concentrations of three different amphipathic peptides (SB-37, Shiva-1, and Vishnu), and enhanced proliferation was determined by uptake of 3Hthymidine with treated cells compared with control cultures. Enhanced proliferation of 3T3 cells was observed in cultures containing 50 μM or less SB-37. The primary study consisted of 263 four-cell- to eight-cell-stage mouse embryos from naturally bred mice and incubated in Whitten's medium containing 0.2, 1, or 10 μM of the amino terminus of an amphipathic cecropin B analog (Vishnu) or in Whitten's medium alone. Embryos were cultured to the hatched blastocyst stage, and effect of treatment was determined by the rate of growth to that stage of development. Statistical analysis revealed that culture in all three levels of Vishnu significantly accelerated in vitro growth of these stages of preimplantation embryos compared with controls. These results indicate that Vishnu promotes increased cleavage rates of embryos in vitro. A growth factor receptor clustering mechanism of action is proposed. This peptide may have some potential as an embryo culture medium additive to enhance in vitro growth rate.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310204
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    Importance of mammalian sperm metalloendoprotease activity during the acrosome reaction to subsequent sperm-egg fusion: Inhibitor studies with human sperm and zona-free hamster eggs (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 122-130 
    Details
    ISSN: 1040-452X
    Keywords: Fertilization ; Phosphoramidon ; Membrane fusion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have previously shown that each of the metalloendoprotease (MEP) inhibitors phosphoramidon, diethylenetriaminepentaacetic acid, and carbobenzoxy-L-phenlalanine, when present only during the human sperm acrosome reaction (AR), will not inhibit the AR or sperm motility but will decrease the number of sperm that penetrate zona-free hamster eggs. The present study was designed to investigate whether this inhibition of penetration is due to an effect on sperm binding to the egg plasma membrane and/or to an effect on the actual membrane fusion event. In these studies we used ionomycin to initiate the AR and assayed binding in a Ca2+-free medium and fusion in Ca2+-containing medium in the same experiment. Eggs were loaded with the fluorescent dye Hoechst 33342, and the appearance of fluorescence in a sperm head indicated that fusion had occurred. The three MEP inhibitors reduced binding only slightly but inhibited the actual fusion step by 50-60% (determined with an equation that corrected for any inhibition of fusion due to inhibition of binding). MEP inhibitors present only during gamete interactions had little or no effect on fusion. We also found that phosphoramidon-inhibitable MEP activity was released during the ionomycin-initiated AR. Incubation of AR supernatant containing MEP activity with previously acrosome-reacted, phosphoramidon-treated sperm resulted in a large reversal of the phosphoramidon-inhibitory effect on sperm-egg fusion. These results support the hypothesis that the acrosomal phosphoramidon-inhibitable MEP released during the AR acts directly or indirectly during that event to increase the fusibility of the sperm plasma membrane region required for subsequent sperm-egg fusion.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310206
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    Announcement (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 160-160 
    Details
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310211
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  • 196
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    U2 small nuclear RNA localization and expression during bovine preimplantation development (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 231-240 
    Details
    ISSN: 1040-452X
    Keywords: Maternal mRNA ; mRNA processing ; Mammalian development ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: This study describes the localization of the U2 small nuclear RNA (snRNA) and the major U snRNA group ribonucleoproteins (snRNPs) during bovine preimplantation development. In vitro maturation, fertilization, and oviductal epithelial cell coculture methods were employed to produce several developmental series totalling over 2,000 preimplantation-stage bovine oocytes and embryos. These oocytes and preimplantation embryos were processed for in situ hybridization, immunofluorescence and Northern blotting methods. The U2 snRNA and the major U group snRNPS were localized initially over the germinal vesicle (GV) of preovulatory oocytes but following GV breakdown were released throughout the ooplasm. They subsequently reassociated with both pronuclei during fertilization. From the two-cell to the blastocyst stages, the U2 snRNA and U snRNPs were localized to the interphase nucleus of each blastomere. The levels of U2 snRNA throughout bovine preimplantation development were determined by probing a Northern blot containing total RNA isolated from the following preimplantation bovine embryo stages: one to two cell, eight to 16 cell, early morula (〉32 cell), and late morula/early blastocysts. The levels of U2 snRNA remained constant between the one-cell and eight-to 16-cell bovine embryo stages but increased 4.4-fold between the eight- to 16-cell stage and the late morula/early blastocyst stages. The results suggest that a maternal pool of snRNAs is maintained in mammalian preimplantation embryos regardless of the duration of maternal control of development.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310402
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    Requirement for glucose during in vitro culture of sheep preimplantation embryos (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 253-257 
    Details
    ISSN: 1040-452X
    Keywords: Glucose ; Pyruvate ; Lactate ; Embryo culture ; Sheep ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Glucose utilization by sheep embryos was examined in 8-cell (N = 36) and blastocyst (N = 36) stages, by measuring conversion of [5-3H]glucose to 3H2O. Fifty percent glucose utilization occurred at 0.79 ± 0.69 mM for 8-cell embryos and ∼0.06 ± 0.15 mM for blastocysts. Development of 1- and 2-cell sheep embryos (N = 264) was examined under different glucose concentrations (0, 1.5, 3, or 6 mM) and in the presence or absence of 0.33 mM pyruvate and 3.3 mM lactate (PL). Overall, the presence of glucose was detrimental (P 〈 0.001) to embryonic development. By contrast, the presence of pyruvate and lactate was beneficial (P〈0.001) to development. An interaction was observed between the concentration of glucose and presence or absence of PL (P 〈0.05). An optimum level of glucose occurs at 0-3 mM in the presence of PL (P ±0.1). Development to the blastocyst stage was observed in medium when supplemented with amino acids and albumin alone. Thus, glucose metabolism is not critical for embryonic development, but beneficial at low concentrations. High concentrations can inhibit development, possibly by inhibiting the tricarboxylic acid (TCA) cycle. Sheep embryos may also be using amino acids as an energy source for development.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310405
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    Inhibitory effect of purines in meiotic maturation of denuded mouse oocytes (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 280-286 
    Details
    ISSN: 1040-452X
    Keywords: Mouse ; Denuded oocytes ; Purines ; Germinal vesicle breakdown ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The potential action of purines, such as hypoxanthine and adenosine, in meiotic arrest was examined using denuded mouse oocytes. The spontaneous meiotic maturation of denuded oocytes was significantly inhibited by hypoxanthine and/or adenosine in a dose-dependent manner. Germinal vesicle breakdown (GVBD) was inhibited even at a low concentration (1 nM) of hypoxanthine, when hypoxanthine was microinjected into the cytoplasm of denuded oocytes. This inhibitory action was potentiated by co-injection with allopurinol, a metabolic blocker of hypoxanthine that can block a metabolic pathway to uric acid. By contrast, a microinjection of adenosine was no longer effective in inhibiting GVBD. Inhibitory action of purines in meiotic maturation was correlated with sustaining intracellular cAMP levels. GVBD was resumed by econazole, one of the nitroimidazole derivatives which act as inhibitors of catalytic subunit of adenylate cyclase. This compound was effective in counteracting the effect of adenosine, but not the action of 3-isobutyl-1-methylxanthine (IBMX) on GVBD, indicating that adenosine is probably exerted at the level of oocyte plasmalemma. These data suggest that the inhibitory action of hypoxanthine and adenosine in oocyte meiotic maturation may be involved in the regulation of cAMP metabolism in a differential manner.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310409
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    Protein and nuclear changes in pig eggs at fertilization (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 287-296 
    Details
    ISSN: 1040-452X
    Keywords: Phosphorylation ; Protein synthesis ; Pronuclei ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The nuclear restructuring that occurs between insemination and full pronuclear formation in pig eggs is accompanied by posttranslational changes to specific egg proteins. Sperm penetration begins in vitro at 3 hr postinsemination (hpi). By 5 hr, decondensing sperm heads and anaphase II plates are observed in 50% of eggs, and, by 8 hpi, both male and female pronuclei have formed. Three consistent changes to the pattern of newly synthesised proteins are triggered in this period; they affect the 46K, 25K, and 22K polypeptides. Changes are also triggered in the 180-200K polypeptides and in the 14K polypeptides, but these are highly variable. The same changes in the prefertilization pattern were observed when prelabelled eggs were used and new protein synthesis was suppressed. The first and most abrupt change involves the apparent catabolic elimination of a group of 46K unphosphorylated polypeptides (pl 7.3-6.4), whose synthesis was greatest before germinal vesicle breakdown but declined slowly in the final phase of maturation, then declined precipitously after activation. Ageing (beyond maturation) also leads to the disappearance of these polypeptides. The progressive disappearance of a set of 25K polypeptides and the concomitant appearance of a dominant 22K polypeptide is the most characteristic fertilization-induced modification to porcine egg proteins. These modifications begin within 1 hr of sperm penetration or activation, are specific to the pig, and involve heavily phosphorylated polypeptides (25K, pl 6.7-6.0) whose synthesis is begun in the early metaphase I stage. Dual ([35S] and [32P]) labelling, protein blocking experiments, and use of alkaline phosphatase suggest that dephosphorylation selectively affects these 25K polypeptides and is mainly or wholly responsible for converting them (completely within 6 hr) to a single, new (22K, pl 7.6) species that is positively charged. The 25K/22K polypeptide modification has a close temporal relationship with the formation of the male and female pronuclei.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310410
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    Intracellular CA2+ response of rabbit oocytes to electrical stimulation (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 9-16 
    Details
    ISSN: 1040-452X
    Keywords: Activation ; Calcium ; Fura-2 ; Electrical pulse ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Electrical stimulation is known to cause activation in mammalian oocytes, possibly by eliciting an elevation in intracellular calcium (Ca2+). This study reports intracellular Ca2+ concentrations in mature rabbit oocytes using the Ca2+ indicator fura-2. Calcium levels were determined prior to, during, and after the administration of an electrical pulse (3.6 kV/cm for 60 μsec). Baseline Ca2+ levels ranged from 30 to 90 nM. The intracellular Ca2+ transient evoked by a pulse, peaked at 11 sec, was highly variable in amplitude (40-300 nM) and returned to prepulse levels within 300 sec. Electrically stimulated oocytes did not exhibit repetitive Ca2+ transients. The size of the cytoplasmic Ca2+ rise was influenced by the duration of the pulse, the field strength and the concentrations of external Ca2+ (P 〈 0.05). Oocytes electrically stimulated in the presence of 100 μM CaCl2, which evoked Ca2+ transients with a mean magnitude of 120 nM, activated at a higher rate (P 〈 0.05) than oocytes stimulated in the presence of either higher or lower levels of external Ca2+. Although oocytes electrically shocked at 16-18 hr after administration of human chorionic gonadotropin (hphCG) activated at a lower rate than oocytes stimulated at 22-24 hphCG (P 〈 0.05), their intracellular Ca2+ response to the pulse was similar (P 〈 0.05). These results indicate that electrical pulse parameters and extracellular Ca2+ concentrations can be used to modulate intracellular Ca2+ levels and optimize oocyte activation rates. Furthermore, the data suggest that as the oocyte ages it becomes more responsive to a given intracellular Ca2+ elevation. © 1992 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080320103
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