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  • 1
    Digitale Medien
    Digitale Medien
    Brain development in hydrocephalic-polydactyl, a recessive pleiotropic mutant in the mouse (1977)
    Springer
    Virchows Archiv 374 (1977), S. 205-214 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Brain development ; Hereditary hydrocephalus ; Non-obstructive hydrocephalus ; Recessive pleiotropic mutant ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Animals homozygous for the recessive, pleiotropic, mutation hpy (hydrocephalic-polydactyl) progressively lag behind their wild-type littermates in increase in body weight and brain dry weight over the period from 1–40 days post-partum; many homozygotes die within the first 14 days after birth. Light microscope observations of serial sections of brains revealed a mild to severe dilation of the entire ventricular system and damaged ependyma. Ciliated ependymal cells appeared reduced in number and destruction of ependymal cells over wide areas of the ventricular surfaces was observed. Preliminary scanning electron microscope studies confirmed the light microscope observations and revealed large numbers of erythrocytes and phagocytes associated with the ependymal surface. Neither the histological studies nor experiments involving intracerebral injections of tracer dyes demonstrated obstruction or stenosis of the aqueduct of Sylvius. Individual neurons appeared to be present in normal numbers and to be developing normally and at the same rate as in wild-type animals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00427115
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  • 2
    Digitale Medien
    Digitale Medien
    Abnormal cilia in a male-sterile mutant mouse (1983)
    Springer
    Virchows Archiv 400 (1983), S. 77-86 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Axonemal defects ; Cilia ; Mouse ; Male-sterile mutant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In mice homozygous for the mutation hydrocephalic-polydactyl (hpy) ciliary axonemes from tracheal, oviducal, and ependymal lining cells showed a variety of abnormalities. Defects included: a deficiency of inner dynein arms, extra central tubules, a displacement of one outer doublet and/or the central tubules, and double axonemes. More than one kind of defect was seen in some axonemes. None of the types of defects observed in mutants were encountered in equivalent samples from non-mutant littermates. Except for the most common defect, the deficiency in dynein arms, which occured to about the same extent (approximately 34%) in all three tissues, there were marked variations in frequency among the tissue types with respect to the other defects. In general, defects such as central tubule anomalies, displaced tubules, and double axonemes occured with the highest frequencies in axonemes from tracheal epithelial cells and with the lowest frequencies in samples of oviducal epithelium. Fused cilia were seen only in ependymal cell samples. Some of the defects encountered were common to sperm flagella axonemes while others appeared restricted to somatic tissues, suggesting, perhaps, each tissue type may exert its own modulating influence on the expression of the mutant gene.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00627011
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  • 3
    Digitale Medien
    Digitale Medien
    The immotile cilia syndrome (1983)
    Springer
    Virchows Archiv 399 (1983), S. 265-275 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Axonemal defects ; Immotile cilia syndrome ; Mouse ; Male ; sterile mutant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary When homozygous the recessive, pleiotropic, mutationhpy (hydrocephalic-polydactyl) produces post-natal hydrocephalus, complete sterility in males, and reduced reproductive performance in females. Because the fertility problems and the development of hydrocephalus could arise as consequences of defective flagella and ciliary axonemes, this mutant type might serve as a useful animal model for the immotile cilia syndrome. Ultrastructural defects seen in axonemes of flagella, and of cilia from the trachea, oviduct, and ependyma included: a deficiency of inner dynein arms (the most frequent defect); an absence of one or both central-pair tubules; extra central tubules; a displacement of one outer doublet and/or the central-pair tubules. Some axonemes showed more than one of these defects. The frequency of dynein-deficient axonemes in all three tissues was similar (about 35%) and fell within the range reported for human patients with the immotile cilia syndrome. On this basis, this mutant type might be considered as a useful animal model for such studies. There were no indications of situs inversus, nor was there a marked increase in respiratory problems. Sohpy/hpy mice do not exhibit all of the clinical symptons characteristic of the human condition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00612944
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  • 4
    Digitale Medien
    Digitale Medien
    Nucleoprotein Synthesis in the New-born Mouse (1964)
    [s.l.] : Nature Publishing Group
    Nature 204 (1964), S. 574-574 
    Details
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Table 1 DNA-Feulgen Histone-fast green New-born liver New-born kidney 3-54 ± 0-19 (49) 1-96 ± 0-07 (52) 4-64 + 0-17 (13) 3-30 ± 0-04 (49) 1-93 ± 0-07 (34) 3-50 (6) In the mouse, the onset of parturition appears to be accompanied by a virtual cessation of mitosis in ...
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1038/204574a0
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  • 5
    Digitale Medien
    Digitale Medien
    DNA-protein relations during microsporogenesis of Tradescantia (1950)
    Springer
    Chromosoma 4 (1950), S. 369-392 
    Details
    ISSN: 1432-0886
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. The morphology of gametogenesis in Tradescantia paludosa is reviewed. 2. Microscopic photometric measurements indicate (a) a progressive increase in DNA content from the time of tetrad formation until microspore mitosis; (b) there is equipartition of DNA between generative and vegetative nuclei; (c) that there is a further increase in DNA content of the vegetative nucleus prior to anthesis, although it is not possible to measure DNA content in the generative nucleus at this stage; (d) that the pollen nuclei initially contain the diploid amount of DNA in a haploid set of chromosomes; and (e) there is very good agreement between the results of the present work and microchemical findings published elsewhere by Ogur and co-workers (1951). 3. A similar cycle obtains in the case of the proteins; the rate of synthesis during development is however much faster than in the case of the DNA. The data also indicate a rapid synthesis of protein by the vegetative nucleus immediately following the microspore division. Also there appears to be a correlation between the onset of cytoplasmic basophilia and the decrease in volume of the vegetative nucleus (presumably loss of protein), just prior to anthesis. 4 Observations on acid and basic staining reactions are discussed in relation to growth and differentiation of the microspore and pollen grain.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00325780
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  • 6
    Digitale Medien
    Digitale Medien
    Cytochemical localization of non-specific esterase and acid phosphatase in spermatozoa of the mouse (Mus musculus) (1972)
    Springer
    Histochemistry and cell biology 33 (1972), S. 169-180 
    Details
    ISSN: 1432-119X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This paper describes methods for the cytochemical demonstration of non-specific esterase and acid phosphatase activities in spermatozoa of the mouse. The acetate and phosphate esters of 1-naphthol were used as substrates, and hexazonium pararosanilin was used as coupler in both techniques. Specificity was assured by the use of appropriate positive and negative controls. Best results were obtained with unfixed smears which had been stored at room temperature for a few days prior to use. Chemical fixation, especially with formol-calcium solutions, is not recommended for use with rodent spermatozoa. According to our investigations the murine acrosome contains very low levels of non-specific esterase and acid phosphatase which are not amenable to detection by the “standard” methods employing short incubations and/or with material fixed in a formalin-containing fixative.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305744
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  • 7
    Digitale Medien
    Digitale Medien
    Spermatogenesis revisited (1981)
    Springer
    Cell & tissue research 221 (1981), S. 169-180 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Spermiogenesis ; Mouse ; Male sterility ; p s p s/hpy hpy ; Geneinteraction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In male mice homozygous for both p s and hpy, two recessive, pleiotrophic, mutations, gametogenesis is normal through meiosis but no functional spermatozoa are produced. Spermiogenesis is abnormal from the Golgi phase on. The types of abnormalities seen during the early and mid-stages of Spermiogenesis are characteristic of those associated with the presence of the p s mutation whereas those associated with the hpy mutation appear during the later stages of spermatid development. While centriolar ultrastructure was normal, axonemal structures were only rarely encountered and no late spermatids with recognizable flagella were seen. Some late spermatids showed head abnormalities of the type characteristic of the ps mutation while others were recognizable as being of the hpy type. A released “gamete” usually consisted of a distorted nucleus and associated acrosome enclosed in a tightly fitting plasma membrane. No spermatids exhibiting a novel phenotype were encountered. The findings support the view that, despite their simultaneous presence in the double homozygote, each mutation acts autonomously. These studies also allow a similar inference to be made with respect to the extent of the interrelationship of the other major sub-processes of Spermiogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216579
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  • 8
    Digitale Medien
    Digitale Medien
    Spermatogenesis revisited (1977)
    Springer
    Cell & tissue research 180 (1977), S. 173-186 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Spermatogenesis ; Mouse ; Male sterility ; p-Locus mutant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Male mice homozygous for the recessive p-locus allele p s are sterile. Spermatogenesis is normal through the completion of meiosis, but is abnormal from the Golgi phase of spermiogenesis on. During acrosome formation various abnormalities appear, ranging from atypical Golgi-acrosome complexes to multiple acrosome “implantation” sites on the spermatid nuclei. In many developing acrosomal caps the distribution of acrosomal material is irregular. During the nuclear elongation phase, bundles of microtubules oriented parallel to the manchette have been seen lying in cylindrical invaginations of some spermatid nuclei. In later spermatids, chromatin condensation appears to proceed normally but may be unduly delayed in reaching completion. These various perturbations give rise to a wide spectrum of abnormal spermatozoa ranging from spermatozoa with heads of near-normal morphology to highly bizarre heads which have lost their chromatin. Sperm flagellar ultrastructure is normal and all sperm tails; even those devoid of recognizable heads, are highly motile. These findings support the view that the development of the sperm head is under the control of a group of genes distinct from those mediating events involved in flagella development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00231950
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  • 9
    Digitale Medien
    Digitale Medien
    Spermatogenesis revisited (1977)
    Springer
    Cell & tissue research 180 (1977), S. 187-201 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Spermiogenesis ; Mouse ; Male sterility ; hpy mutant ; Flagella dysgenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Gametogenesis is normal through meiosis and the earliest phases of spermiogenesis in male-sterile mice homozygous for the recessive, pleiotropic, mutation hpy (hydrocephalic-polydactyl). However, structurally complete sperm flagella were not encountered. Instead, partially assembled axonemal structures and/or poorly organized aggregates of other tail components (mitochondria, outer coarse fibers) were seen at the posterior poles of nuclei in older spermatids. The ultrastructure of centrioles in spermatids was normal, but that of axonemes associated with them was not. These findings suggest that the observed flagella dysgenesis results from defects in assembly rather than from defective intiation centers. Released “gametes” usually consisted of distorted nuclei and associated acrosome enclosed in a relatively close fitting plasma membrane. Perturbations of sperm head development were also encountered; they included extreme nuclear elongation, and distortion of the acrosome and underlying nuclear material by inpushings of finger-like processes of Sertoli cells. It is believed that sperm head anomalies are secondary consequences of the mutant condition. The findings support the view that the hpy locus represents one of a number of genes primarily involved in the mediation of flagella development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00231951
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  • 10
    Digitale Medien
    Digitale Medien
    Spermatogenesis revisited (1973)
    Springer
    Cell & tissue research 138 (1973), S. 155-169 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Spermiogenesis ; Mouse ; Multinucleate spermatids ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This ultrastructural study confirms and extends the light microscope findings of Bryan (1971) concerning the presence and developmental fate of multinucleate spermatids. Four main classes of cells: uninucleate-individual, uninucleate-conjoined, multinucleate-conjoined, and multinucleate-individual, were identified along with a few instances of more complex syncytial organizations. When the respective nuclei in a given multinucleate are far enough apart, each develops autonomously but in synchrony with its neighbors. When nuclei are intimately associated, the “normal” pattern of spermiogenesis may be altered, giving rise to highly bizarre spermatozoa. Commonly, a single Golgi complex serves a pair of nuclei and gives rise to a “T-shaped” acrosome which binds the nuclei together. During the ensuing nuclear elongation phase, such units are invested by a single manchette. Pairs of axonemes within a common plasma membrane have also been encountered. These ultrastructural findings indicate that multinucleate spermatids are true components (not artifacts) of the seminiferous epithelium of normal animals. The presence of such cells and the unusual developmental consequences which can arise as a result of the multinucleate state must be taken into account when evaluating the course of spermatogenesis in cases of mutation- or chemically-induced infertility.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306605
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