Capacitation of Ram Spermatozoa and Penetration of the Ovine Egg

Pe, Mattner

doi:10.1038/199772a0

Cited by 35 publications

(14 citation statements)

References 5 publications

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“…Restall (1961) suggested that the improved lambing rate achieved by running teaser rams with the ewes after insemination (Lysov & Simanov, 1955;Restall, 1961;Schindler & Eyal, 1961) might be attributed to the release of oxytocin and improved sperm transportation. It is interesting to speculate that the relationship between heat length and time of ovulation, and perhaps the time necessary for sperm capacitation (Mattner, 1963), might be involved.…”

Section: Discussionmentioning

confidence: 99%

Use of Probit Analysis in a Study of the Effect of the Ram on Time of Ovulation in the Ewe

Parsons¹,

Hunter²,

Rayner³

1967

Reproduction

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To investigate the relationship between oestrus and time of ovulation from the start of heat and the effect of the ram on this relationship, 200 ewes, half of which had been run with rams continuously during oestrus, were slaughtered at intervals after the end of heat. The method of probit analysis was used to fit multiple regression equations for percentage of ewes ovulated (as a probit) in terms of slaughter time and heat length. From these equations, estimates of mean ovulation times for various heat lengths were calculated. In the control group, which was teased at 4-hr intervals to determine lengths of heat, ovulation occurred, on the average, shortly after the end of oestrus. Although duration of oestrus was shorter when the sexes were continuously associated, ovulation occurred later. In addition, there was a positive correlation between heat length and time of ovulation in this group, but not in the control group.

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Section: Discussionmentioning

confidence: 99%

Use of Probit Analysis in a Study of the Effect of the Ram on Time of Ovulation in the Ewe

Parsons¹,

Hunter²,

Rayner³

1967

Reproduction

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“…Even the time interval for capacitation varies among mammals. Typical in vivo capacitation times for different mammals are rabbit, 6 hr (Chang, 1951); guinea pig, 4 hr (Yanagimachi and Mahi, 1976); golden hamster, 3.5 hr (Strauss, 1956); ferret, 3.5 hr (Chang and Yanagimachi, 1963); pig, 2-3 hr (Hunter and Dziuk, 1968); sheep, 1.5 hr (Mattner, 1963); mouse, 0.5-1 hr (Braden and Austin, 1974); and cat, 0.5-2 hr (Hamner et al, 1968a). This time requirement appears to be inherent in the sperm of the species rather than its environment, since capacitation of sperm in heterologous oviducts is dependent on the sperm rather than the oviduct in which they were placed (Saling and Bedford, 1981).…”

Section: Capacitation In Vivomentioning

confidence: 98%

Sperm surface components involved in the control of the acrosome reaction

1985

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Several lines of evidence suggest that decapacitation of sperm occurs normally in the male reproductive tract, and as a result the acrosome is stabilized and the acrosome reaction is controlled. Since the defining experiments in 1951, where decapacitation was reversed in the female reproductive tract by capacitation, investigations have pursued the molecular events of this process. This review attempts to examine critically the older literature and compare that perspective with the current theories. The theories for decapacitation of sperm include the possible role of a peptide decapacitation factor, a glycoprotein-mediated steroid transfer to the sperm, masking of a galactosyl transferase by some macromolecule-containing carbohydrate, preclusion of calcium influx by a binding protein, and sperm interaction with the acrosome stabilizing factor. Although these theories are diverse, there are some unifying aspects. However, there remain some major unanswered questions. For example, although we point to some circumstantial evidence that infers a single decapacitation factor, this needs to be further substantiated. It is concluded that with the purification of a macromolecule involved in capacitation, specific proposals on the mechanism of capacitation, and new tools to evaluate the capacitation process, it is likely that another decade will not pass without emergence of a unifying molecular theory of sperm capacitation.

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“…To study losses of surface components into reproductive tract secretions of the ewe, washed 125I-labelled spermatozoa (2-3 IO8 cells/ml) were incubated in non-labelled uterine fluid and/or oviduct fluid at 37°C. To compensate for the dilution (1:1 v/v) of the fluids with Ringer, the spermatozoa were incubated in uterine and oviduct fluid for 1 h and 3 h, respectively, or more than twice the average time required for capacitation of ram spermatozoa in vivo (Mattner, 1963). After 1 h incubation in uterine fluid, a sample was removed to assess the motility on a warm microscopic stage and to determine the surface labelling pattern.…”

Section: Methodsmentioning

confidence: 99%

Surface transformation of ram spermatozoa in uterine, oviduct and cauda epididymal fluids in vitro

Voglmayr¹,

Sawyer²

1986

Reproduction

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Genital tract fluids were collected continuously from conscious ewes through catheters inserted surgically into the uterus and oviducts. Cauda epididymal spermatozoa and fluid were obtained through catheters inserted into the transected vas deferens. The washed spermatozoa were labelled using the surface-specific chloroglycoluril-Na125I procedure. High-resolution electrophoretic analysis of sperm plasma membrane preparations revealed a partial loss of a major surface component (i.e. Mr 97,000) during incubation in uterine and oviduct fluids. This specific loss resulted in a shift in radioactivity distribution toward an Mr 24,000 component which had been previously identified as a sialoglycoprotein. No significant changes in the distribution of radiolabelled surface components were detectable when the spermatozoa were incubated in synthetic medium. Incubation of unlabelled spermatozoa in 125I-labelled uterine fluid showed that adsorption of exogenous fluid components was highly selective; an Mr 16,000 polypeptide was greatly enriched on the sperm surface although it was only a minor component in the incubation fluid. Adsorption of labelled oviduct fluid components was also selective and involved predominantly high molecular weight components (i.e. Mr 140,000, 95,000, 78,000, 53,000). When spermatozoa were incubated in labelled cauda epididymal fluid after exposure to unlabelled uterine and oviduct fluids, several fluid components were incorporated by the plasma membrane, indicating that surface renovation of 'capacitated' spermatozoa may be a more general process rather than a specific event. These results suggest that capacitation of ram spermatozoa involves loss of specific surface proteins as well as selective adsorption of exogenous fluid components and point to a polypeptide in uterine fluid as an active constituent.

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Capacitation of Ram Spermatozoa and Penetration of the Ovine Egg

Cited by 35 publications

References 5 publications

Use of Probit Analysis in a Study of the Effect of the Ram on Time of Ovulation in the Ewe

Use of Probit Analysis in a Study of the Effect of the Ram on Time of Ovulation in the Ewe

Sperm surface components involved in the control of the acrosome reaction

Surface transformation of ram spermatozoa in uterine, oviduct and cauda epididymal fluids in vitro

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