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  • 1
    Electronic Resource
    Electronic Resource
    Transmission electron microscopy of impaired spermatogenesis in an avian hybrid (1985)
    New York, NY : Wiley-Blackwell
    Gamete Research 12 (1985), S. 357-371 
    Details
    ISSN: 0148-7280
    Keywords: hybrid dysgenesis ; spermatogenesis ; transmission electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The mechanisms involved in the impaired spermatogenesis of male goldfinch x canary hybrids were investigated by transmission electron microscopy and compared with spermatogenesis in the testes of the parent species.In the parent species the testes were of normal structure, with the only unusual observation being that the Sertoli cells were variable in cytoplasmic electron density. In hybrid birds the Sertoli cells were either electron dense or electron lucent with respect to both nucleus and cytoplasm.In the hybrids examined in this study, no spermatozoa were produced. Spermatogenic stages were arrested without formation of synaptonemal complexes. Centrioles were abnormally arranged in both somatic and germ cells. When they moved away from the basement lamina the germ cells degenerated and were phagocytosed. No focal tight junctions were present between Sertoli cells overlying what would normally have been the basal compartment of the tubule. The basement lamina was unusually thickened, peritubular cells were abnormal in structure, and numerous plasma cells were present in the interstitial tissue.The observations reported here suggest that there was an immunological basis for degeneration of germ cells in the hybrid testis.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120120404
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  • 2
    Electronic Resource
    Electronic Resource
    The generation and propagation of double waves in mosquito (Aedes notoscriptus) sperm-tails (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 241-250 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoan movement ; insect; axoneme ; accessory tubule ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the mosquito Aedes notoscriptus nine accessory tubules develop from the doublets of the axoneme whose single central fibre forms late in spermiogenesis. The 9 + 9 + 1 mosquito sperm-tail propagates two waves of differing frequency and amplitude. The structural basis for the movement is of interest.Mosquito sperm were demembranated until all movement ceased and were reactivated with a solution containing adenosine triphosphate (ATP). They immediately moved in a normal fashion. Like untreated sperm, they always propagated double waves. This indicates that the plasma membrane does not control the double wave.After sonicating sperm treated as above, the high-frequency, low-amplitude waves sometimes propagated alone beyond a damaged region of sperm-tail, whereas the large-amplitude, low-frequency waves never propagated alone beyond a damaged region. This suggests that the latter waves are generated by an anterior site, possibly the centriole or centriole adjunct. The structure that propagates the large amplitude wave is not known; possibly the accessory tubules may slide against the axonemal doublets.Any region of the sperm-tail is capable of generating and propagating the low-amplitude, high-frequency wave, for which the structure responsible is probably the axoneme.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040308
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  • 3
    Electronic Resource
    Electronic Resource
    Action of phosphatidylcholine in protecting ram sperm from cold shock (1986)
    New York, NY : Wiley-Blackwell
    Gamete Research 15 (1986), S. 43-56 
    Details
    ISSN: 0148-7280
    Keywords: calcium ; ultrastructure ; motility ; respiration ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Rapid cooling (cold shocking) of washed ejaculated ram sperm to 0°C irreversibly reduced motility, tail beat frequency, and respiration and increased the uptake of 45Ca2+. The plasma membranes were removed from the sperm head, and the acrosomes were detached from the nuclei. The plasma membranes of the middle piece were removed, and the mitochondria contained pale and expanded cristae, similar in appearance to ATP-deprived mitochondria in the “condensed” configuration. The presence of 2.0 mg/ml phosphatidylcholine (lecithin) in the medium prevented ultrastructural damage on cold shock, and the motility, tail beat frequency, respiratory rate, and calcium uptake were maintained at levels similar to washed sperm. As the “protective” effect of phosphatidylcholine against cold shock was maintained to a certain extent after rewashing and centrifuging the sperm prior to cold shock, the interaction of phosphatidylcholine with ram sperm membranes may be fairly “tight” and not easily disrupted.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120150106
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  • 4
    Electronic Resource
    Electronic Resource
    Susceptibility of epididymal boar sperm to cold shock and protective action of phosphatidylcholine (1987)
    New York, NY : Wiley-Blackwell
    Gamete Research 17 (1987), S. 355-373 
    Details
    ISSN: 0148-7280
    Keywords: motility ; respiration ; calcium ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Rapidly cooling (cold shocking) washed cauda boar sperm irreversibly reduced motility and respiration and greatly increased the uptake of 45Ca2+; the plasma membranes were removed and the acrosomes detached from nuclei. The motility, respiration, and calcium uptake of the less mature caput sperm were largely unaffected; and there was little damage to the ultrastructure. This indicates that boar sperm becomes less resistant to cold shock as they mature in the epididymis.The oxygen uptake, glucose breakdown, and lactic acid production of control caput sperm was less than that of cauda sperm. This suggest that the maturation of sperm in the epididymis of the boar involves an increase in both the glycolytic and oxidative phases of glucose metabolism.The presence of 2.0 mg/ml phosphatidylcholine (lecithin) in the medium prevented ultrastructural damage to cauda sperm on cold shock, and motility and respiration were maintained at levels similar to those of control sperm. Although the presence of phospholipid reduced the large calcium influx following cold shock, it was still greater that that of control sperm.The “protective” effect against cold shock was not maintained after rewashing the sperm free of phosphatidylcholine prior to cold shock, indicating a fairly “loose” interaction of the phospholipid with boar sperm membranes that was easily disrupted.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120170408
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  • 5
    Electronic Resource
    Electronic Resource
    Impaired spermatogenesis in the finch hybrid L. castaneothorax by L. punctulata: Transmission electron microscopy and genetic analysis (1987)
    New York, NY : Wiley-Blackwell
    Gamete Research 17 (1987), S. 157-171 
    Details
    ISSN: 0148-7280
    Keywords: sterility ; intercellular bridges ; centrioles ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: As part of a project to determine whether there is any correlation between the form of hybrid sterility and the genetic relatedness of the parental species, we studied a male intrageneric hybrid between two finch species (Lonchura custaneothorax × L. punctuluta), and compared the ultrastructural basis of hybrid sterility in this species with that reported by Swan [1985] for an intergeneric bird hybrid. In the latter study the sterility appeared to have an autoimmune basis, due to lack of Sertoli-Sertoli tight junctions. In the hybrid examined in the present study, lanthanum tracing showed that the junctions were tight. There was no testicular immune reaction; the parental species were almost identical in chromosomal constitution, having only a small inversion difference on chromosome 5, and only two structural protein differences could be detected through examination of the variation at 38 protein loci. Nevertheless, the hybrid appeared sterile and had the following ultrastructural testicular features. Intercellular bridges where present were usually abnormal in structure; centrioles in a centriole pair were arranged in parallel. Many spermatocytes and spermatids degenerated and were phagocytosed by Sertoli cells. Some spermatids progressed to mature testicular spermatozoa in sperm bundles, but commonly had multiple (2-4) axonemes or disrupted doublets and accessory fibers. The multiple axonemes present in most spermatids inserted separately into the base of the nucleus and the multiple centrioles were capable of organizing separate neck structures. We conclude that these cytological abnormalities were caused by genic effects and discuss why they appeared to be restricted to the germ line.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120170207
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of ethanol and methanol on the motility of Saccostrea commercialis sperm and sperm models (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 30 (1991), S. 241-249 
    Details
    ISSN: 1040-452X
    Keywords: Asymmetry ; Ethanol ; Methanol ; Permeabilization ; pH ; Sperm ; Track velocity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The organic solvents methanol and ethanol at concentrations of 2.5% and 5% (v/v), respectively, were found to significantly (P 〈 0.001) decrease the radius of curvature and track velocity of S. commercialis sperm. To observe the effects of the solvent directly on the axoneme, S. commercialis sperm models were prepared by extraction with Triton X-100 and reactivation with ATP in media containing acetate anions, DTT, magnesium, and cAMP. Concentrations of 0.1% Triton X-100 demembranated sperm while 0.01% and 0.05% Triton X-100 permeabilized sperm. Sperm models were successfully produced after reactivation with 1 mM ATP. At pH 8.25, 1% (v/v) ethanol or methanol was observed to increase waveform asymmetry and significantly (P 〈 0.001) decrease track velocity of 0.1% Triton X-100 demembranated sperm models. Similarly 1% (v/v) ethanol increased tailwave asymmetry and decreased track velocity of 0.01% and 0.05% Triton X-100 permeabilized sperm models. Reactivated motility of 0.05% Triton X-100 permeabilized sperm models prepared at pH 7.8 were poor and improved after treatment with 7% (v/v) ethanol, which increased waveform asymmetry and doubled the track velocity of sperm. This stimulatory effect of ethanol was unchanged in the presence of the alcohol dehydrogenase inhibitor pyrazole. Concerning the precise mechanism of action of ethanol on the axoneme, we conclude that a stimulatory or inhibitory effect of ethanol is dependent on the pH of the sperm model system used.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080300312
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  • 7
    Electronic Resource
    Electronic Resource
    Effect of triton X-100 on ultrastructure, reactivation, and motility characteristics of ram spermatozoa (1986)
    New York, NY : Wiley-Blackwell
    Gamete Research 15 (1986), S. 361-371 
    Details
    ISSN: 0148-7280
    Keywords: extraction ; ATP ; partial demembranation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: For optimal extraction and reactivation of ram sperm, glutamate, dithiothreitol, magnesium, and cyclic AMP were required in a medium of pH 7.9. On extraction with 0.01 % Triton X-100, ram sperm were only partially demembranated, and extensive areas of plasma membrane remained intact especially in the midpiece region. Treatment with 0.1% Triton X-100 removed all plasma membranes and extracted the mitochondrial membrane and matrix. In the absence of ATP, 16.6% ± 0.4 of the partially demembranated sperm were motile, but sperm extracted with 0.1% Triton X-100 were completely immotile. On adding ATP partially demembranated sperm reactivated better (81.6% ± 2.8) than sperm completely demembranated in 0.1 % Triton X-100 (39.5% ± 4.6). The release of intracellular LDH rose linearly with increasing concentrations of the detergent from 0.01 to 0.05%, at which it plateaued. There was a significant increase in beat frequency and forward velocity of partially demembranated sperm when treated with ATP. Partially demembranated sperm had intact mitochondria that presumably were still able to produce ATP, although the spermatozoan movement was stimulated by exogenous ATP.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120150408
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