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  • 1
    Electronic Resource
    Electronic Resource
    Cytological events associated with in vitro aged and fertilized rabbit eggs (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 195 (1979), S. 357-374 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The morphogenetic events associated with rabbit eggs aged in vitro for 12 to 50 hours prior to mixing with sperm have been examined by light and electron microscopy. After 12 hours in culture, morphological alterations of the meiotic spindle and the cortex of unfertilized eggs were evident. By 24 to 50 hours in culture, unfertilized eggs contained subnuclei, structures which formed when individual and/or groups of meiotic chromosomes dispersed and became invested by a double-laminated structure reminiscent of a nuclear envelope.Although most eggs obtained 11.5 to 12 hours after induced ovulation and in vitro fertilized displayed morphogenetic patterns similar to those described for in vivo fertilized ova, some (10%) contained three pronuclei. Many eggs obtained 13 to 15 hours after induced ovulation and subsequently mixed with sperm in vitro appeared to undergo processes of fertilization typical of in vivo fertilized eggs, however, approximately 30% contained subnuclei in association with the male pronucleus. Few eggs (15%) aged 12 hours prior to in vitro fertilization displayed patterns of pronuclear development and association typical of fertilized unaged ova. Subnuclei developed in many of the fertilized ova. Supernumerary sperm nuclei, which did not develop into male pronuclei, were observed in some zygotes. Cleavage of eggs aged 12 hours prior to fertilization was abnormal or retarded. After 24 hours in culture approximately 16% of the eggs fertilized. Seventy percent of the fertilized eggs failed to Support the development of a male or female pronucleus.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091950209
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  • 2
    Electronic Resource
    Electronic Resource
    An ultrastructural analysis of spontaneous activation of hamster eggs aged in vivo (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 179 (1974), S. 27-55 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In an effort to elucidate various aspects involving the initiation of development, the morphogenesis of the spontaneously activated egg of the golden hamster was examined at the light and electron microscopic levels of observation. Spontaneous activation of the unfertilized hamster egg occurs upon prolonged incubation within the oviduct, i.e., aging in vivo, and may include the formation of the second polar body and the development of one or several pronuclei. In many instances the activated egg resembles the inseminated ovum at the pronuclear stage of fertilization. Occasionally the activated egg will divide and yields a structure which is morphologically similar to the two-cell stage. Development beyond the two-cell stage was not observed. Even though a number of events exhibited by the aging hamster egg mimic those of the fertilized, many are indicative of cellular degeneration. Such processes include, for example, the aggregation of organelles into fairly homogeneous clusters, the budding of portions of the cortex of the egg containing cortical granules into the perivitelline space, the accumulation of vesicles within the ooplasm and the structural modification of microvilli. All activated eggs, at every period investigated (6 to 66 hours post-ovulation), contained cortical granules.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091790104
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  • 3
    Electronic Resource
    Electronic Resource
    Differences in mouse ovarian cells as distinguished by horseradish peroxidase labelling (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 193 (1979), S. 357-365 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The extracellular space of mouse ovarian follicles and stroma contained horseradish peroxidase (HRP) reaction product one minute after intravenous injection of the tracer. In addition to pinocytotic uptake of the tracer, non-vesicular staining with HRP reaction product, heretofore unrecognized, was noted in a variety of ovarian cell-types. This diffuse staining was correlated with changes in cellular morphology suggestive of degeneration. These findings are discussed in relation to the composition of cell populations comprising follicles and ovarian stroma and alterations in cell function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091930303
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  • 4
    Electronic Resource
    Electronic Resource
    An ultrastructural study of preovulatory apical development in mouse ovanan follicles: Effects of indomethacin (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 205 (1983), S. 159-168 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The effects of the prostaglandin synthesis inhibitor, indomethacin, on the preovulatory morphology of apical follicle walls have been examind by transmission electron microscopy. Immature mice, superovulated with 5 IU pregnant mare serum (PMS) followed 40 hours later by 80 IU luteinizing hormone (LH) were treated with either 10 mg/kg indomethacin or an equivalent volume of the indomethacin vehicle 10 minutes prior to LH. Follicular apices from both groups were compared at 12 hours post-LH. Indomethacin treatment suppressed many of the morphological changes normally occurring in the apex during preovulatory development. Whereas apices from vehicle treated animals demonstrated marked deterioration, dissociation, and thinning of tissue, the cell layers of apices from indomethacin-treated animals remained thickened and tightly packed, with limited signs of disruption. The results presented herein are consistent with the idea that prostaglandins are essential mediators of ovulation and suggest that these lipids augment apical rupture by mobilizing granulosa cells and stimulating the loss of connective tissue elements.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092050206
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  • 5
    Electronic Resource
    Electronic Resource
    A cytochemical study of nuclear changes in fertilized hamster eggs (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 207 (1983), S. 325-334 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Nucleoprotein changes during male and female pronuclear development have been examined in fertilized hamster eggs utilizing the ammoniacal silver reaction (ASR) at the light and ultrastructural levels of observation. Prior to its incorporation, the paternally derived chromatin was heavily laden with ASR product. Immediately upon gamete fusion the sperm nucleus underwent a dramatic increase in staining, suggesting an augmentation in the availability of reactive sites already present in the sperm nucleus or an accumulation of “new” reactive sites from the egg cytoplasm. With subsequent transformations of the sperm nucleus into a male pronucleus, there was a progressive reduction in ASR product associated with the paternal chromatin. Concomitantly, the condensed maternal chromosomes remaining in the zygote after the conclusion of meiosis dispersed and developed into a female pronucleus; these changes were accompanied by a progressive decrease in ASR staining. At the conclusion of pronuclear development, the morphologically similar male and female pronuclei were diffusely stained with the ASR. The increase in ASR staining of the sperm nucleus immediately following gamete fusion demonstrates a major effect of the egg cytoplasm on the paternal chromatin that, heretofore, has not been recognized. This augmentation and the following decrease in ASR staining may reflect changes in nucleoproteins during pronuclear development. Differences in nuclear staining are discussed in light of previous studies of nucleoprotein transitions at fertilization.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092070211
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  • 6
    Electronic Resource
    Electronic Resource
    Fertilization cones of inseminated sea urchin (Arbacia punctulata) oocytes: Development of an asymmetry in plasma membrane topography (1986)
    New York, NY : Wiley-Blackwell
    Gamete Research 15 (1986), S. 137-151 
    Details
    ISSN: 0148-7280
    Keywords: glycocalyx ; microvilli ; cytochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Electron microscopic and cytochemical investigations were carried out on inseminated Arbacia oocytes comparing structural and chemical properties of their microvillous surface and fertilization cones. Early fertilization cones (up to 4 min postinsemination) were relatively small, smooth surface projections of cytoplasm that engulfed the incorporated sperm nucleus. However, in contrast to surrounding microvillous areas of the oocyte surface, enlarged fertilization cones (8 to 15 min postinsemination) had a distinctive crenated appearance that persisted until their regression. When examined by various cytochemical techniques, membrane delimiting fertilization cones had a much lower affinity for agents that stain negatively charged and carbohydrate moieties (cationized ferritin, concanavalin A, ruthenium red, and alcian blue) than did other regions of the oocyte surface. This difference in surface properties of membrane delimiting the site of sperm-egg fusion was not due solely to incorporated sperm plasma membrane and did not occur when inseminated oocytes were incubated with cytochalasin B. Little or no difference in the membrane of the fertilization cone versus microvillous areas was observed when inseminated eggs were freeze-fractured or prepared with agents (filipin and polymixin B) to demonstrate β-hydroxysterols and anionic phospholipids. These observations indicate that membrane delimiting the fertilization cone differs from the remainder of the oocyte surface and suggests that following insemination significant rearrangements of surface molecules take place within the egg plasmalemma that give rise to asymmetries in membrane topography.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120150205
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  • 7
    Electronic Resource
    Electronic Resource
    Membrane specializations associated with the acrosomal complex of sea urchin sperm as revealed by immunocytochemistry and freeze fracture replication (1989)
    New York, NY : Wiley-Blackwell
    Gamete Research 23 (1989), S. 429-440 
    Details
    ISSN: 0148-7280
    Keywords: acrosome reaction ; intraumembranous particles ; monoclonal antibody detection ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Observations, employing freeze fracture replication and electron microscopic imrnunochemis-try, have been carried out to determine structural correlations of the plasma membrane domain occupied by a 210 kDa protein involved in the acrosomal reaction of sea urchin sperm and recognized by the monoclonal antibody, J10/14 (Trimmer et al: Cell 40:697-703, 1985; Proceedings of the National Academy of Sciences of the United States of America 83: 9055-9059, 1986). Immunogold-J10/14 staining of acrosorne-intact sperm was intense along the flagellum and a narrow collar just posterior to the sperm apex that surrounded the acrosomal complex (acrosomal vesicle and subjacent anterior nuclear fossa containing g-actin). Counts of gold particles revealed a density (average number of particles/μm2 of surface area) eightfold greater along the plasma membrane associated with the acrosomal complex than membrane delimiting the remainder of the sperm head. The collar of J10/14 staining was isomorphic with a dense aggregation of intramembranous particles in the P-face of the plasma membrane and a thin cytoplasmic region that surrounded the acrosomal complex. In acrosomc-reacted sperm, intense J10/14 staining was distributed along the flagellum and sperm head; prominent anterior staining was not apparent in all specimens. The density of gold particles associated with plasma membrane delimiting components of the former acrosomal complex, nucleus and mitochondrion, as well as the total average number of particles along the entire sperm surface, were increased in sperm acrosome-reacted with A-23187. Concomitant with this change in staining was the disappearance/reduction of the collars of intramembranous particles and cytoplasm. These observations indicate that plasma membrane components (210 kDa protein and intramembranous particles) and the collar of cytoplasm which are associated with the acrosomal complex are functionally, as well as structurally related. Analyses of particle density distributions along acrosome- and non-acrosome-reacted sperm suggest that the different staining patterns observed may be brought about by the recognition of cryptic sites at the time of the acrosomal reaction.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120230408
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  • 8
    Electronic Resource
    Electronic Resource
    Incorporation and fate of specific sperm plasma membrane components following insemination as revealed by ultrastructural immunocytochemistry (1989)
    New York, NY : Wiley-Blackwell
    Gamete Research 23 (1989), S. 215-228 
    Details
    ISSN: 0148-7280
    Keywords: Membrane fusion ; membrane fluidity ; protein diffusion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Studies have been carried out to 1) further characterize sperm specific plasma membrane polypeptides (33 and 35 kDa) that are recognized by a monoclonal antibody previously described (Longo, 1989) and 2) follow the incorporation and dispersal of these proteins within plasmalemmae of monospermic and polyspermic sea urchin (Arbacia punctuluta) eggs and oocytes utilizing immunocytochemical methods at the ultrastructural level of observation. Only sperm labeled when incubated with monoclonal antibody to the 33 and 35 kDa proteins followed by colloidal gold-tagged second antibody. Colloidal gold label was observed on the egg plasma membrane immediately after gamete membrane fusion; the amount and extent of label, i.e., the distance from the site of sperm incorporation, increased with time postinsemination. By 20 min postinsemination approximately one hemisphere of the inseminated egg/oocyte was associated with label. The expanding distribution of colloidal gold label on inseminated eggs and oocytes vs. time reflects the free diffusion of 33 and 35 kDa sperm surface proteins among egg/oocyte plasma membrane components. Label was also found in forming endocytotic vesicles, suggesting that sperm plasma membrane proteins may be internalized.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120230208
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  • 9
    Electronic Resource
    Electronic Resource
    Examination of living and fixed gametes and early embryos stained with supravital fluorochromes (Hoechst 33342 and 3,3′-dihexyloxacarbocyanine iodide) (1986)
    New York, NY : Wiley-Blackwell
    Gamete Research 15 (1986), S. 267-283 
    Details
    ISSN: 0148-7280
    Keywords: fluorochromes ; fertilization ; nuclear events ; mitochondria ; surf clam ; sea urchin ; hamster ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have examined living and fixed gametes and early embryos of surf clams, sea urchins, and hamsters stained with the supravital dyes Hoechst 33342 for DNA and 3,3′-dihexyloxacarbocyanine iodide (DIOC6) for mitochondria and endoplasmic reticulum. Hoechst staining (10 μM) was confined exclusively to egg and sperm chromatin and, in living marine specimens, did not interfere with sperm motility, fertilization, or nuclear activity during meiosis or early embryogenesis. Although Hoechst staining did not appear to affect the motility of hamster sperm, only zonae-free eggs inseminated. Because chromatin retained Hoechst 33342 stain during fertilization, the paternally and maternally derived chromosomes of living and fixed preparations fluoresced and their number, organization, and location within the zygote cytoplasm could be determined. Hence, polyspermy and other nuclear abnormalities were amenable to examination in these stained preparations. DIOC6 staining (8.7 μM) was restricted primarily to the mitochondria of spermatozoa. Eggs stained with DIOC6 (0.87 to 8.7 μM) were brightly fluorescent because of their size and the presence of large numbers of mitochondria and other DIOC6-positive organelles. Sea urchin and surf clam sperm stained with DIOC6 fertilized unstained eggs and the location of the incorporated sperm mitochondrion up to first cleavage was followed. Although hamster sperm stained with DIOC6 were less motile than unstained sperm, they were capable of inseminating only zonae-free eggs. These observations demonstrate that staining with supravital fluorochromes provides a rapid and useful method to analyze macromolecular and organelle changes in a variety of living and fixed gametes and embryos.
    Additional Material: 36 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120150308
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  • 10
    Electronic Resource
    Electronic Resource
    Cytoplasmic and sperm nuclear transformations in fertilized ammonia-activated sea urchin (Arbacia punctulata) eggs (1983)
    New York, NY : Wiley-Blackwell
    Gamete Research 8 (1983), S. 65-78 
    Details
    ISSN: 0148-7280
    Keywords: sea urchin ; ammonia-activation ; fertilization ; fertilization cone ; sperm asters ; pronuclear development ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Studies examining cytoplasmic and sperm nuclear transformations in sea urchin (Arbacia punctulata) eggs inseminated at different periods after ammonia activation have been caried out at the light- and electron-microscopic levels of observation. Arbaca eggs treated with ammonia-seawater demonstrated chromosome condensation after DNA synthesis and underwent a chromosome cycle similar to that described for Lytechinus [Mazia, 1947]. Cortical granule reaction, fertilization cone formation, and sperm aster development in eggs fertilized at 20 (interphase), 50 (prometaphase), and 180 (interphase) min after ammonia activation were structurally simialr to processes in untreated zygotes. Cyclical changes in the formation of fertilization cones and sperm asters, as reported for eggs fertilized after activation by agents that induce a cortical granule reaction, were not observed. Although sperm nuclear transformations were prolonged (14 vs 18 min), male pronuclei that developed in eggs fertilized 20 min after ammonia activation were morphologically similar to those observed in fertilized, untreated ova and incorporated 3H-thymidine. Sperm incorporated into eggs at 50 min after ammonia activation underwent nuclear envelope breakdown and chromatin despersion; however, 3H-thymidine incorporation was not observed, and male pronuclei rarely developed (less than 5% of all specimens examined). Subsequent to dispersion, the paternal chromatin condensed into chromosomes which were associated with an aster. These results demonstrate that although ammonia-activated eggs inseminated at interphase or prometaphase undergo similar cytoplasmic alterations, sperm nuclear transformations vary with the chromosome cycle of the egg.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120080108
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