Sperm selection in natural conception: what can we learn from Mother Nature to improve assisted reproduction outcomes?

Human Reproduction Update, Год журнала: 2015, Номер 21(6), С. 711 - 726

Опубликована: Сен. 19, 2015

In natural conception only a few sperm cells reach the ampulla or site of fertilization. This population is selected group since motile can pass through cervical mucus and gain initial entry into female reproductive tract. animals, some studies indicate that by tract recovered from uterus oviducts have higher fertilization rates but this not universal finding. Some species show less discrimination in selection abnormal do arrive at oviduct. contrast, assisted technologies (ART) utilize more random population. review we contrast journey spermatozoon vivo vitro discuss context developing new preparation techniques for ART. A literature examining characteristics spermatozoa compared with recent developments methods. Contrasts similarities are presented. New being developed to aid diagnosis, To date progress has been frustrating these methods provided variable benefits improving outcomes after It likely mechanisms enforced nature will provide valuable information regard vitro. Identifying properties those which oviduct also be important development effective tests semen quality. examine value see how much guidance ART gleaned processes vivo.

Язык: Английский

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How sperm competition shapes the evolution of testes and sperm: a meta-analysis

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 2020, Номер 375(1813), С. 20200064 - 20200064

Опубликована: Окт. 18, 2020

Females of many species mate with multiple males, thereby inciting competition among ejaculates from rival males for fertilization. In response to increasing sperm competition, are predicted enhance their investment in production. This prediction is so widespread that testes size (correcting body size) commonly used as a proxy even the absence any other information about species' reproductive behaviour. By contrast, debate whether selects smaller or larger has persisted nearly three decades, empirical studies demonstrating every possible response. Here, we synthesize 40 years research meta-analytical framework determine how evolution number (i.e. and head, midpiece, flagellum total length) influenced by varying levels across species. Our findings support long-held assumption higher associated relatively testes. We also find clear evidence increases all components length. discuss these results context different theoretical predictions general patterns breeding biology selective environment sperm. article part theme issue ‘Fifty competition’.

Язык: Английский

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Sperm Storage in the Female Reproductive Tract

Annual Review of Animal Biosciences, Год журнала: 2015, Номер 4(1), С. 291 - 310

Опубликована: Ноя. 3, 2015

The capacity for sperm storage within the female reproductive tract occurs widely across all groups of vertebrate species and is exceptionally well developed in some reptiles (maximum duration seven years) fishes >1 year). Although there are many reports on both occurrence diverse its adaptive benefits, few studies have been directed toward explaining mechanisms involved. In this article we review recent findings birds mammals an effort to develop hypotheses that could be translated into research applications animal breeding technologies. There pockets evidence suggest local epithelial cells, sometimes arranged as tubules, can respond spermatozoa by producing heat shock proteins providing environment rich antioxidants. Moreover, immune system seems tolerate arrival spermatozoa, while retaining ability combat infectious microorganisms.

Язык: Английский

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Sperm form and function: what do we know about the role of sexual selection?

Reproduction, Год журнала: 2018, Номер 155(5), С. R229 - R243

Опубликована: Фев. 20, 2018

Sperm morphological variation has attracted considerable interest and generated a wealth of predominantly descriptive studies over the past three centuries. Yet, apart from biophysical linking sperm morphology to swimming velocity, surprisingly little is known about adaptive significance form selective processes underlying its tremendous diversification throughout animal kingdom. Here, we first discuss challenges examining in an evolutionary context why our understanding it far complete. Then, review empirical evidence for how sexual selection theory applies evolution function, including putative secondary traits borne by sperm.

Язык: Английский

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Ovarian fluid allows directional cryptic female choice despite external fertilization

Nature Communications, Год журнала: 2016, Номер 7(1)

Опубликована: Авг. 16, 2016

Abstract In species with internal fertilization, females can favour certain males over others, not only before mating but also within the female’s reproductive tract after mating. Here, we ask whether such directional post-mating (that is, cryptic) female mate choice occur in external fertilization. Using an vitro sperm competition experiment, demonstrate that ovarian fluid (ovarian fluid) changes outcome of by decreasing importance number thereby increasing relative velocity. We further show does differentially affect from alternative male phenotypes, generally enhances velocity, motility, straightness and chemoattraction. Under natural conditions, likely increases paternity preferred parental phenotype, as these release fewer faster sperm. These results imply have greater control fertilization potential to exert selection on than previously thought possible.

Язык: Английский

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Importance of sperm morphology during sperm transport and fertilization in mammals

Asian Journal of Andrology, Год журнала: 2016, Номер 18(6), С. 844 - 844

Опубликована: Янв. 1, 2016

After natural or artificial insemination, the spermatozoon starts a journey from site of deposition to place fertilization. However, only small subset spermatozoa deposited achieves their goal: reach and fertilize egg. Factors involved in controlling sperm transport fertilization include female reproductive tract environment, cell-cell interactions, gene expression, phenotypic traits. Some significant determinants are known (i.e., motility DNA status), but many traits still indecipherable. One example is influence dimensions shape upon within genital towards oocyte. Biophysical associations between size may progression through tract, uncertainties remain concerning how morphology influences process, whether per se involved. Moreover, such explanations do not allow possibility that capable distinguishing fertile on basis morphology, as seems be case with biochemical, molecular, genetic properties. This review focuses evolution putative role selection uterus ability

Язык: Английский

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Gamete-mediated mate choice: towards a more inclusive view of sexual selection

Proceedings of the Royal Society B Biological Sciences, Год журнала: 2018, Номер 285(1883), С. 20180836 - 20180836

Опубликована: Июль 18, 2018

‘Sperm competition’—where ejaculates from two or more males compete for fertilization—and ‘cryptic female choice’—where females bias this contest to suit their reproductive interests—are now part of the everyday lexicon sexual selection. Yet physiological processes that underlie these post-ejaculatory episodes selection remain largely enigmatic. In review, we focus on a range cellular- and molecular-level processes, known be fundamental fertilization across most (if not all) sexually reproducing species, point putative role in facilitating at level cells gametes, called ‘gamete-mediated mate choice’ (GMMC). way, collate accumulated evidence GMMC different mating systems, emphasize evolutionary significance such non-random interactions among gametes. Our overall aim review is build inclusive view by showing choice often acts nuanced ways than has traditionally been assumed. We also bridge conceptual divide between proximal mechanisms reproduction, adaptive explanations patterns sperm–egg are emerging an increasingly diverse array taxa.

Язык: Английский

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Conceptual developments in sperm competition: a very brief synopsis

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 2020, Номер 375(1813), С. 20200061 - 20200061

Опубликована: Окт. 18, 2020

The past half century has seen the development of field post-ejaculatory sexual selection, sequel to selection for mate-acquisition (pre-ejaculatory) described by Darwin. In richness and diversity adaptations, rivals that pre-ejaculatory selection. Anisogamy—and hence two sexes—likely arose primeval gamete competition, sperm competition remains a major force maintaining high numbers. equivalent male–male matings, was an intense ancestral form typically weakening as mobility internal fertilization developed in many taxa, when some expenditure became diverted into competition. Sperm theory been relatively successful explaining variation relative testes size numbers per ejaculate is becoming more phenotype. generated other male adaptations such seminal fluid proteins variously modify female reproduction towards interests, copulatory plugs, prolonged copulations guarding behaviour reduce remating probability, which result conflict. This short survey conceptual developments intended broad overview, mainly primer new researchers. article part theme issue ‘Fifty years competition'.

Язык: Английский

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Do sperm possess a molecular passport? Mechanistic insights into sperm selection in the female reproductive tract

Molecular Human Reproduction, Год журнала: 2015, Номер 21(6), С. 491 - 501

Опубликована: Март 9, 2015

Most male mammals produce far more spermatozoa on a daily basis than is strictly necessary for reproduction and females have evolved mechanisms that prevent all but small minority from reaching the vicinity of their oocytes. One potential explanation stringent selection developed these as way avoiding polyspermy well exercising post-copulatory choice over characteristics fertilizing spermatozoon. Relatively little known about how processes would operate, here we use evidence biochemical, molecular genetic studies sperm transport in support hypothesis proposing female reproductive tract can read interpret spermatozoon's 'molecular passport' or signature. Such signature permit only highly selected population to reach fertilize oocyte. Moreover, criteria might not be concerned with successful ability, could also tailored suit qualities individual females.

Язык: Английский

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Sperm selection in the female mammalian reproductive tract. Focus on the oviduct: Hypotheses, mechanisms, and new opportunities

Theriogenology, Год журнала: 2015, Номер 85(1), С. 105 - 112

Опубликована: Июль 22, 2015

Язык: Английский

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