Capacitation

Jaiswal, Bijay S.; Eisenbach, Michael

doi:10.1016/b978-012311629-1/50005-x

Cited by 58 publications

(57 citation statements)

References 374 publications

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“…Although highly speculative, mature sperm derived from cells carrying the FGFR3 achondroplasia mutation may have a selective advantage for sperm motility or capacitation in utero. The molecular mechanisms involved in capacitation are not well known, but protein phosphorylation on tyrosine residues appears to be important (35) and relevant given FGFR3 function. To explain the paternal age effect, any selective advantage would have to increase with age perhaps in association with known changes that occur in the male reproductive system during normal aging (36).…”

Section: Discussionmentioning

confidence: 99%

The observed human sperm mutation frequency cannot explain the achondroplasia paternal age effect

Tiemann‐Boege

Navidi²,

Grewal³

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

152

133

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The lifelong spermatogonial stem cell divisions unique to male germ cell production are thought to contribute to a higher mutation frequency in males. The fact that certain de novo human genetic conditions (e.g., achondroplasia) increase in incidence with the age of the father is consistent with this idea. Although it is assumed that the paternal age effect is the result of an increasing frequency of mutant sperm as a man grows older, no direct molecular measurement of the germ-line mutation frequency has been made to confirm this hypothesis. Using sperm DNA from donors of different ages, we determined the frequency of the nucleotide substitution in the fibroblast growth factor receptor 3 (FGFR3) gene that causes achondroplasia. Surprisingly, the magnitude of the increase in mutation frequency with age appears insufficient to explain why older fathers have a greater chance of having a child with this condition. A number of alternatives may explain this discrepancy, including selection for sperm that carry the mutation or an age-dependent increase in premutagenic lesions that remain unrepaired in sperm and are inefficiently detected by the PCR assay.

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Section: Discussionmentioning

confidence: 99%

The observed human sperm mutation frequency cannot explain the achondroplasia paternal age effect

Tiemann‐Boege

Navidi²,

Grewal³

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

152

133

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“…Only capacitated spermatozoa are able to undergo the acrosome reaction in response to natural inducers ZP, progesterone or GABA [Roldan et al 1994;Shi and Roldan 1995b;Shi et al 1997;Yanagimachi 1994]. This has been considered to be indicative of the completion of capacitation [Florman and Babcock 1991;Jaiswal and Eisenbach 2002;Visconti et al, 1998;Yanagimachi 1994]. Therefore, the sum of ''B þ AR'' patterns of spermatozoa during incubation that undergo capacitation is generally taken as an indicator for completion of capacitation [Barboni et al 1995;DasGupta et al 1994;Visconti et al 1998;Wang et al 2003;Xu et al 2007].…”

Section: Discussionmentioning

confidence: 99%

“…The changes that confer fertilizing ability are known as capacitation. Only capacitated spermatozoa are able to undergo either the spontaneous or induced acrosome reaction [Florman and Babcock 1991;Yanagimachi 1994;Jaiswal and Eisenbach 2002]. Capacitation is reversible, but the acrosome reaction is not [Yanagimachi 1994].…”

Section: Introductionmentioning

confidence: 99%

Activation of GABA_AReceptor/Cl⁻Channel and Capacitation in Rat Spermatozoa: HCO₃⁻and Cl⁻are Essential

Jin

Chen

Zhou

et al. 2009

Systems Biology in Reproductive Medicine

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This study was designed to determine whether HCO 3 À and Cl À are required for the activation of the GABA A receptor/Cl À channel (GBRC) by GABA and the subsequent capacitation of rat sperm. Spermatozoa from adult Sprague Dawley rats were incubated in four different media: modified complete rat fertilization medium (mRFM), Cl À -deficient (Cl À -DF) mRFM, HCO 3 À -DF mRFM, andCl À -DF HCO 3 À -DF mRFM, with or without GBRC agonists (GABA and progesterone) or GBRC antagonists (bicuculline and picrotoxin) for 0-6 h under capacitating conditions. Sperm capacitation and hyperactivation were assessed by chlortetracycline staining and computer-assisted sperm analysis, respectively. The results showed that GABA added to the mRFM accelerated capacitation and hyperactivation, followed by increase in the acrosome reaction, reaching maximum value after 5 h. Progesterone also accelerated sperm capacitation and hyperactivation. Bicuculline and picrotoxin, antagonists of GABA, blocked the effects of both GABA and progesterone acceleration of sperm capacitation and hyperactivation. Sperm capacitation required both Cl À and HCO 3 À . These results indicate that activation of GBRC may contribute to sperm capacitation and hyperactivation, and that both HCO 3 À and Cl À are essential. This is the first report of a close relationship between HCO 3 À /Cl À transport and the activation of GBRC in rat sperm capacitation and hyperactivation.

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“…When there is sperm competition, males tend to ejaculate many times, and in this way they ensure that the female tract has sperm populations ready to fertilize at different times, thus maximizing the chances that spermatozoa will be ready when ovulation occurs. In addition, ejaculates contain subpopulations of spermatozoa that behave differently in terms of timing of capacitation (30), and this could be a means to ensure that when ovulation occurs, there will be a proportion of spermatozoa ready to fertilize. Using aggregation chimeras, Krzanowska (31) found that when spermatozoa from two strains were placed in competition, spermatozoa from one strain were more successful, but this advantage decreased if females were inseminated several hours before ovulation, suggesting that more rapid capacitation was responsible for the competitive advantage of spermatozoa.…”

Section: Discussionmentioning

confidence: 99%

“…Yet the race to fertilize the available ova does not only imply greater motility to reach the site of fertilization first. Mammalian spermatozoa need to undergo a process known as ''capacitation'' to be able to fertilize the ova (28)(29)(30). Capacitation can take up to several hours, and indirect experimental evidence suggests that when spermatozoa are placed in direct competition, those that capacitate faster are more successful at fertilizing the ova (31).…”

mentioning

confidence: 99%

Sperm competition enhances functional capacity of mammalian spermatozoa

Gomendio

Martin-Coello

Crespo

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

118

116

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When females mate promiscuously, sperm from rival males compete within the female reproductive tract to fertilize ova. Sperm competition is a powerful selective force that has shaped sexual behavior, sperm production, and sperm morphology. However, nothing is known about the influence of sperm competition on fertilization-related processes, because it has been assumed that sperm competition only involves a race to reach the site of fertilization. We compared four closely related rodent species with different levels of sperm competition to examine whether there are differences in the proportion of spermatozoa that become ready to interact with the ovum (''capacitated'') and in the proportion of spermatozoa that experience the acrosome reaction in response to a natural stimulant. Our results show that differences between species in levels of sperm competition were associated with the proportion of spermatozoa that undergo capacitation and with the proportion of spermatozoa that respond to progesterone, an ovum-associated signal. Sperm competition thus favors a larger population of spermatozoa that are competent to fertilize, and spermatozoa that are more sensitive to the signals emitted by the ovum and that may penetrate the ova vestments more rapidly. These results suggest that, contrary to previous assumptions, competition between spermatozoa from rival males continues at the site of fertilization. These findings may have further evolutionary implications because the enhanced competitiveness of spermatozoa during fertilization may increase the risk of polyspermy to females. This could lead to antagonistic coevolution between the sexes and may contribute to the explanation of the rapid divergence observed in fertilization-related traits.sperm function ͉ capacitation ͉ acrosome reaction fertilization ͉ antagonistic coevolution

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Capacitation

Cited by 58 publications

References 374 publications

The observed human sperm mutation frequency cannot explain the achondroplasia paternal age effect

The observed human sperm mutation frequency cannot explain the achondroplasia paternal age effect

Activation of GABA_AReceptor/Cl⁻Channel and Capacitation in Rat Spermatozoa: HCO₃⁻and Cl⁻are Essential

Sperm competition enhances functional capacity of mammalian spermatozoa

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Capacitation

Cited by 58 publications

References 374 publications

The observed human sperm mutation frequency cannot explain the achondroplasia paternal age effect

The observed human sperm mutation frequency cannot explain the achondroplasia paternal age effect

Activation of GABAAReceptor/Cl−Channel and Capacitation in Rat Spermatozoa: HCO3−and Cl−are Essential

Sperm competition enhances functional capacity of mammalian spermatozoa

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Activation of GABA_AReceptor/Cl⁻Channel and Capacitation in Rat Spermatozoa: HCO₃⁻and Cl⁻are Essential