scholarly journals The seminal coagulum favours passage of fast-moving sperm into the uterus in the black-handed spider monkey

Reproduction ◽  
2008 ◽  
Vol 136 (4) ◽  
pp. 411-421 ◽  
Author(s):  
Leonor Hernández-López ◽  
Ana Lilia Cerda-Molina ◽  
Denisse L Páez-Ponce ◽  
Ricardo Mondragón-Ceballos
Keyword(s):  
Sperm Competition ◽  
Sexual Conflict ◽  
Reproductive Tract ◽  
Methodological Approach ◽  
Female Reproductive Tract ◽  
Spider Monkey ◽  
Menstrual Phase ◽  
Sperm Survival ◽  
And Migration ◽  
Physiological And Biochemical

In addition to gametes, mammalian internal fertilisation has required the evolution of assorted anatomical, physiological and biochemical devices to deal with intra- and inter-sexual conflict such as sperm competition and female cryptic choice respectively. The seminal coagulum of primates and other mammals is viewed as one of such devices. Among primates, the seminal coagulum characteristically occurs in multi-male and multi-female species, leading us to suppose that it intervenes in sperm competition. However, it can also provide cues to the female reproductive tract about male desired or undesired traits, and therefore deter or favour sperm survival and migration. The present work investigates whether the seminal coagulum of the black-handed spider monkey enhances sperm fertilisation chances by improving the female reproductive tract conditions, and if the female reproductive tract is ‘blind’ to semen or behaves selectively towards ejaculates of different males. A series of artificial inseminations were done in five females, using the ejaculates of three different males, one at a time, and measuring the presence of distinct types of sperm inside the uteri at 10, 30 and 60 min following the insemination. The presence of coagulum, menstrual phase, and male and female identity only affected fast, straight-moving sperm, with larger amounts of fast sperm appearing inside the uteri when ejaculates had seminal coagulum, as well as when in the periovulatory phase. There was great intra-uterine fast-sperm variation regarding which male's semen inseminated which female. The results provide evidence to account for sexual conflict in the spider monkey as well as a methodological approach to this kind of study.

Effects of condition and sperm competition risk on sperm allocation and storage in neriid flies

2019 ◽  
Author(s):  
Zachariah Wylde ◽  
Angela Crean ◽  
Russell Bonduriansky
Keyword(s):  
Sperm Competition ◽  
Perceived Risk ◽  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
The Body ◽  
Condition Dependence ◽  
Ejaculate Size ◽  
Sperm Competition Risk ◽  
High Condition ◽  
Allocation Strategies

Abstract Ejaculate traits can be sexually selected and often exhibit heightened condition-dependence. However, the influence of sperm competition risk in tandem with condition-dependent ejaculate allocation strategies is relatively unstudied. Because ejaculates are costly to produce, high-condition males may be expected to invest more in ejaculates when sperm competition risk is greater. We examined the condition-dependence of ejaculate size by manipulating nutrient concentration in the juvenile (larval) diet of the neriid fly Telostylinus angusticollis. Using a fully factorial design we also examined the effects of perceived sperm competition risk (manipulated by allowing males to mate first or second) on the quantity of ejaculate transferred and stored in the three spermathecae of the female reproductive tract. To differentiate male ejaculates, we fed males nontoxic rhodamine fluorophores (which bind to proteins in the body) prior to mating, labeling their sperm red or green. We found that high-condition males initiated mating more quickly and, when mating second, transferred more ejaculate to both of the female’s posterior spermathecae. This suggests that males allocate ejaculates strategically, with high-condition males elevating their ejaculate investment only when facing sperm competition. More broadly, our findings suggest that ejaculate allocation strategies can incorporate variation in both condition and perceived risk of sperm competition.

Post-Copulatory Sexual Selection

2021 ◽  
Author(s):  
Patricia L.R. Brennan ◽  
Dara N. Orbach
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Reproductive Tract ◽  
Seminal Fluid ◽  
Fertilization Success ◽  
Female Reproductive Tract ◽  
Cryptic Female Choice ◽  
Trade Offs ◽  
Morphological Criteria

The field of post-copulatory sexual selection investigates how female and male adaptations have evolved to influence the fertilization of eggs while optimizing fitness during and after copulation, when females mate with multiple males. When females are polyandrous (one female mates with multiple males), they may optimize their mating rate and control the outcome of mating interactions to acquire direct and indirect benefits. Polyandry may also favor the evolution of male traits that offer an advantage in post-copulatory male-male sperm competition. Sperm competition occurs when the sperm, seminal fluid, and/or genitalia of one male directly impacts the outcome of fertilization success of a rival male. When a female mates with multiple males, she may use information from a number of traits to choose who will sire her offspring. This cryptic female choice (CFC) to bias paternity can be based on behavioral, physiological, and morphological criteria (e.g., copulatory courtship, volume and/or composition of seminal fluid, shape of grasping appendages). Because male fitness interests are rarely perfectly aligned with female fitness interests, sexual conflict over mating and fertilization commonly occur during copulatory and post-copulatory interactions. Post-copulatory interactions inherently involve close associations between female and male reproductive characteristics, which in many species potentially include sperm storage and sperm movement inside the female reproductive tract, and highlight the intricate coevolution between the sexes. This coevolution is also common in genital morphology. The great diversity of genitalia among species is attributed to sexual selection. The evolution of genital attributes that allow females to maintain reproductive autonomy over paternity via cryptic female choice or that prevent male manipulation and sexual control via sexually antagonistic coevolution have been well documented. Additionally, cases where genitalia evolve through intrasexual competition are well known. Another important area of study in post-copulatory sexual selection is the examination of trade-offs between investments in pre-copulatory and post-copulatory traits, since organisms have limited energetic resources to allocate to reproduction, and securing both mating and fertilization is essential for reproductive success.

scholarly journals Do spermathecal morphology and inter-mating interval influence paternity in the polyandrous beetle Tribolium castaneum?

Behaviour ◽  
2006 ◽  
Vol 143 (5) ◽  
pp. 643-658 ◽  
Author(s):  
Ludovic Arnaud ◽  
Giorgina Bernasconi ◽  
Yves Brostaux ◽  
Eric P. Meyer
Keyword(s):  
Sperm Competition ◽  
Tribolium Castaneum ◽  
Reproductive Tract ◽  
Sperm Storage ◽  
Female Reproductive Tract ◽  
Phenotypic Marker ◽  
Male And Female ◽  
The Difference ◽  
Different Strains

AbstractIn polyandrous insects, postcopulatory sexual selection is a pervasive evolutionary force favouring male and female traits that allow control of offspring paternity. Males may influence paternity through adaptations for sperm competition, and females through adaptations facilitating cryptic female choice. Yet, the mechanisms are often complex, involving behaviour, physiology or morphology, and they are difficult to identify. In red flour beetles (Tribolium castaneum), paternity varies widely, and evidence suggests that both male and female traits influence the outcome of sperm competition. To test the role of spermathecal morphology and of sperm storage processes on the outcome of sperm competition, we mated each of 26 virgin females with two males, one of which carrying a phenotypic marker to assign offspring paternity. We manipulated the interval between mating with the first and the second male, to create different conditions of sperm storage (overlapping and non-overlapping) in the female reproductive tract. To investigate the role of sperm storage more closely, we examined the relationship between paternity and spermathecal morphology in a subset of 14 experimental females. In addition, we also characterized variation in spermathecal morphology in three different strains, wildtype, Chicago black and Reindeer. No significant influence of the intermating interval was found on the paternity of the focal male, although the direction of the difference was in the expected direction of higher last male paternity for longer intervals. Moreover, paternity was not significantly associated with spermathecal morphology, although spermathecal volume, complexity, and tubule width varied significantly and substantially among individuals in all investigated strains.

scholarly journals Apical Sperm Hook Morphology Is Linked to Sperm Swimming Performance and Sperm Aggregation in Peromyscus Mice

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2279
Author(s):  
Kristin A. Hook ◽  
Lauren M. Wilke ◽  
Heidi S. Fisher
Keyword(s):  
Sperm Competition ◽  
Reproductive Tract ◽  
Swimming Performance ◽  
Structural Diversity ◽  
Female Reproductive Tract ◽  
Eutherian Mammal ◽  
Male Sperm ◽  
Specific Variation ◽  
Sperm Swimming Speed

Mammals exhibit a tremendous amount of variation in sperm morphology and despite the acknowledgement of sperm structural diversity across taxa, its functional significance remains poorly understood. Of particular interest is the sperm of rodents. While most Eutherian mammal spermatozoa are relatively simple cells with round or paddle-shaped heads, rodent sperm are often more complex and, in many species, display a striking apical hook. The function of the sperm hook remains largely unknown, but it has been hypothesized to have evolved as an adaptation to inter-male sperm competition and thus has been implicated in increased swimming efficiency or in the formation of collective sperm movements. Here we empirically test these hypotheses within a single lineage of Peromyscus rodents, in which closely related species naturally vary in their mating systems, sperm head shapes, and propensity to form sperm aggregates of varying sizes. We performed sperm morphological analyses as well as in vitro analyses of sperm aggregation and motility to examine whether the sperm hook (i) morphologically varies across these species and (ii) associates with sperm competition, aggregation, or motility. We demonstrate inter-specific variation in the sperm hook and then show that hook width negatively associates with sperm aggregation and sperm swimming speed, signifying that larger hooks may be a hindrance to sperm movement within this group of mice. Finally, we confirmed that the sperm hook hinders motility within a subset of Peromyscus leucopus mice that spontaneously produced sperm with no or highly abnormal hooks. Taken together, our findings suggest that any adaptive value of the sperm hook is likely associated with a function other than inter-male sperm competition, such as interaction with ova or cumulous cells during fertilization, or migration through the complex female reproductive tract.

scholarly journals Rapid evolution of reproductive proteins in abalone and Drosophila

2006 ◽  
Vol 361 (1466) ◽  
pp. 261-268 ◽  
Author(s):  
Tami M Panhuis ◽  
Nathaniel L Clark ◽  
Willie J Swanson
Keyword(s):  
Protein Evolution ◽  
Sexual Conflict ◽  
Reproductive Tract ◽  
Rapid Evolution ◽  
Theoretical Data ◽  
Pathogen Resistance ◽  
Accessory Gland ◽  
Female Reproductive Tract ◽  
Reproductive Proteins ◽  
Accessory Gland Proteins

Observations from different taxa, including plants, protozoa, insects and mammals, indicate that proteins involved in reproduction evolve rapidly. Several models of adaptive evolution have been proposed to explain this phenomenon, such as sexual conflict, sexual selection, self versus non-self recognition and pathogen resistance. Here we discuss the potential role of sexual conflict in the rapid evolution of reproductive genes in two different animal systems, abalone ( Haliotis ) and Drosophila . In abalone, we reveal how specific interacting sperm–egg proteins were identified and discuss this identification in the light of models for rapid protein evolution and speciation. For Drosophila , we describe the genomic approaches taken to identify male accessory gland proteins and female reproductive tract proteins. Patterns of protein evolution from both abalone and Drosophila support the predicted patterns of rapid protein evolution driven by sexual conflict. We stress however that other selective pressures may contribute to the rapid evolution that is observed. We conclude that the key to distinguishing between sexual conflict and other mechanisms of protein evolution will be an integration of genetic, experimental and theoretical data.

scholarly journals Sperm competition in squamate reptiles

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200079
Author(s):  
Christopher R. Friesen ◽  
Ariel F. Kahrl ◽  
Mats Olsson
Keyword(s):  
Sperm Competition ◽  
Reproductive Tract ◽  
Multiple Paternity ◽  
Fertilization Success ◽  
Sperm Storage ◽  
Female Reproductive Tract ◽  
Life History Strategies ◽  
The Face ◽  
And Function ◽  
Sperm Size

Multiple paternity is ubiquitous within the polyphyletic group called ‘reptiles', especially within the lizards and snakes. Therefore, the probability of sperm competition occurring, and being intense, is high. Squamates exhibit a diversity of tactics to ensure fertilization success in the face of sperm competition. The duration of female sperm storage, which can be many months and even years in some species, remains an enigma. Here, we emphasize some mechanisms that might affect patterns of paternity, the source and function of ejaculates and features of the female reproductive tract that may aid in long-term sperm storage. In doing so, we present a new analysis of the relationship between sperm size, the strength of sperm competition and the duration of female sperm storage. Lizards and snakes are a diverse group that has provided many excellent models for the study of an array of life-history strategies. However, when it comes to postcopulatory sexual selection, there is much left to discover. This article is part of the theme issue ‘Fifty years of sperm competition'.

scholarly journals Collective sperm movements in Peromyscus mice are shaped by phylogenetic history and post-copulatory sexual selection

2020 ◽  
Author(s):  
Kristin A. Hook ◽  
W. David Weber ◽  
Heidi S. Fisher
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Reproductive Tract ◽  
Swimming Performance ◽  
Aggregate Size ◽  
Female Reproductive Tract ◽  
Testis Size ◽  
Limited Evidence ◽  
Closely Related Species ◽  
Sperm Migration

AbstractIn some species, sperm form motile, coordinated groups as they migrate through the female reproductive tract. Collective sperm migration is posited to have evolved to improve sperm swimming performance, and thus may be beneficial in a competitive context, but limited evidence supports this theory. Here we investigate sperm aggregation across closely-related species of Peromyscus mice that naturally vary by mating system. We find that phylogenetic history predicts the likelihood that sperm will aggregate but that variation in aggregate size negatively associates with relative testis size, suggesting that sperm competition has a stabilizing effect on this trait. Moreover, we show that sperm aggregation is not kinematically beneficial for all species, and we hypothesize that swimming performance is dependent on the orientation and composition of sperm groups. To test this, we compared sperm from the two sister-species that aggregate most frequently and find that sperm of the species that evolved under intense sperm competition forms aggregates with efficient geometry more frequently than sperm from its monogamous congener. Together, our results are consistent with the hypothesis that sperm aggregation evolved to improve motility in a competitive context; however, when monogamy evolved secondarily, relaxed sexual selection allowed for less efficient strategies to persist.

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