scholarly journals A putative novel role for Eip74EF in male reproduction in promoting sperm elongation at the cost of male fecundity

2019 ◽  
Author(s):  
Sharif Chebbo ◽  
Sarah Josway ◽  
John M. Belote ◽  
Mollie K. Manier
Keyword(s):  
Reproductive Success ◽  
Oocyte Maturation ◽  
Male Reproduction ◽  
Male Reproductive Success ◽  
Sperm Length ◽  
Female Reproductive Success ◽  
Fitness Advantage ◽  
Males And Females ◽  
Opposing Effects ◽  
The Cost

ABSTRACTSpermatozoa are the most morphologically variable cell type, yet little is known about genes controlling natural variation in sperm shape. Drosophila fruit flies have the longest sperm known, which are evolving under postcopulatory sexual selection, driven by sperm competition and cryptic female choice. Long sperm outcompete short sperm but primarily when females have a long seminal receptacle (SR), the primary sperm storage organ. Thus, selection on sperm length is mediated by SR length, and the two traits are coevolving across the Drosophila lineage, driven by a genetic correlation and fitness advantage of long sperm and long SR genotypes in both males and females. Ecdysone induced protein 74EF (Eip74EF) is expressed during post-meiotic stages of spermatogenesis, when spermatid elongation occurs, and we found that it is rapidly evolving under positive selection in Drosophila. Hypomorphic knockout of the E74A isoform leads to shorter sperm but does not affect SR length, suggesting that E74A may be involved in promoting spermatid elongation but is not a genetic driver of male-female coevolution. We also found that E74A knockout has opposing effects on fecundity in males and females, with an increase in fecundity for males but a decrease in females, consistent with its documented role in oocyte maturation. Our results suggest a novel function of Eip74EF in spermatogenesis and demonstrates that this gene influences both male and female reproductive success. We speculate on possible roles for E74A in spermatogenesis and male reproductive success.RESEARCH HIGHLIGHTSEip74EF promotes oocyte maturation in Drosophila. We found evidence that it also promotes sperm elongation in males, but at a cost to male fecundity. Mutant males have shorter sperm but have higher reproductive success, while females have reduced fecundity.

POLYGYNY, REPRODUCTIVE SUCCESS AND CHILD HEALTH IN RURAL ETHIOPIA: WHY MARRY A MARRIED MAN?

2006 ◽  
Vol 39 (2) ◽  
pp. 287-300 ◽  
Author(s):  
MHAIRI A. GIBSON ◽  
RUTH MACE
Keyword(s):  
Reproductive Success ◽  
Male Reproductive Success ◽  
Family Status ◽  
Rural Ethiopia ◽  
Younger Age ◽  
Married Individuals ◽  
Males And Females ◽  
Child Nutritional Status ◽  
And Child Health ◽  
Better Than

Summary.This study examines the reproductive success of men and women in rural Ethiopia as a function of their marital status, specifically by comparing polygamously and monogamously married individuals. In line with predictions from evolutionary theory, polygamy is beneficial to male reproductive success (i.e. producing larger numbers of surviving offspring). The success of polygamously married females depends on wife rank: the first wives of polygamous husbands do better than monogamously married women and much better than second or third wives. These effects are mirrored in child nutritional status: the children of second and third wives have lower weight for height. Due to potential, largely unmeasurable differences in marriageability (quality) between individuals, it was not possible to support a model of either resource-holding polygyny combined with female choice or female coercion into unwanted marriages. First wives of polygamously married men marry at a younger age and attract a higher brideprice, suggesting that both the males and females in the marriage are likely to be of higher quality (due to wealth, family status or some other factor such as beauty). Unions that end up monogamous are likely to be between slightly lower quality individuals; and second and third wives, who marry at the oldest ages and attract the lowest brideprice, may be ‘making the best of a bad job’. The relatively long gap between first and second marriages may mean that first wives of highly marriageable males can enjoy considerable reproductive success before their husbands marry again.

Variation in reproductive success of male and female Columbian ground squirrels (Urocitellus columbianus)

2012 ◽  
Vol 90 (6) ◽  
pp. 736-743 ◽  
Author(s):  
Philip H. Jones ◽  
Jeffrey L. Van Zant ◽  
F. Stephen Dobson
Keyword(s):  
Reproductive Success ◽  
Mating System ◽  
Multiple Paternity ◽  
Ground Squirrels ◽  
Male Reproductive Success ◽  
Offspring Production ◽  
Bateman Gradient ◽  
Coefficients Of Variation ◽  
Males And Females ◽  
Columbian Ground Squirrels

The imbalanced reproductive success of polygynous mammals results in sexual selection on male traits like body size. Males and females might have more balanced reproductive success under polygynandry, where both sexes mate multiply. Using 4 years of microsatellite DNA analyses of paternity and known maternity, we investigated variation in reproductive success of Columbian ground squirrels, Urocitellus columbianus (Ord, 1815); a species with multiple mating by both sexes and multiple paternity of litters. We asked whether male reproductive success was more variable than that of females under this mating system. The overall percentage of confirmed paternity was 61.4% of 339 offspring. The mean rate of multiple paternity in litters with known fathers was 72.4% (n = 29 litters). Estimated mean reproductive success of males (10.27 offspring) was about thrice that of females (3.11 offspring). Even after this difference was taken into account statistically, males were about three times as variable in reproductive success as females (coefficients of variation = 77.84% and 26.74%, respectively). The Bateman gradient (regression slope of offspring production on number of successful mates) was significantly greater for males (βM = 1.44) than females (βF = 0.28). Thus, under a polygynandrous mating system, males exhibited greater variation in reproductive success than females.

scholarly journals Sexually opposite effects of testosterone on mating success in wild rock hyrax

2019 ◽  
Vol 30 (6) ◽  
pp. 1611-1617
Author(s):  
Lee Koren ◽  
Yishai Weissman ◽  
Inbar Schnitzer ◽  
Rosanne Beukeboom ◽  
Einat Bar Ziv ◽  
...  
Keyword(s):  
Mate Guarding ◽  
Female Reproductive Success ◽  
Rock Hyrax ◽  
Proximate Mechanisms ◽  
Physiological Processes ◽  
Procavia Capensis ◽  
Males And Females ◽  
The Cost

Abstract Although males and females share traits, their motivations and needs may be different, due to life-history disparities that lead to divergent selection pressures. Proximate mechanisms underlying differences between the sexes include hormones that mediate the development and activation of suites of traits. Testosterone is associated with morphological features, physiological processes, and social behaviors in both sexes. However, even if present in similar concentrations in the circulation, testosterone often affects males and females differently. We combined behavioral mating observations of the wild polygynandrous rock hyrax (Procavia capensis) with hair testosterone that represents long-term integrated levels. We found that whereas copulation success increases with the rise in testosterone in males it decreases in females. We did not find an association between testosterone and choosiness in either sex. However, we found that males with higher testosterone mate-guarded females with lower testosterone. Our findings show disassortative mating and mate-guarding in respect to testosterone and provide clues to the cost of testosterone for females, in terms of copulation success. These results open up intriguing questions relating to the role of testosterone in mediating a similar trade-off in male and female reproductive success.

The cost of trying: weak interspecific correlations among life-history components in male ungulates

2012 ◽  
Vol 90 (9) ◽  
pp. 1072-1085 ◽  
Author(s):  
Marco Festa-Bianchet
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Life History Traits ◽  
Male Reproductive Success ◽  
Main Determinant ◽  
Young Males ◽  
Asymptotic Size ◽  
Trade Offs ◽  
The Cost ◽  
Slow Growing

Life-history trade-offs are well known in female mammals, but have seldom been quantified for males in polygynous species. I compared age-specific mass, weapon size, survival, and reproductive success of males in eight species of ungulates, and found weak interspecific correlations among life-history traits. Young males tended to have higher reproductive success in rapidly-growing than in slow-growing species, and in species where horns or antlers reached near-asymptotic size over the first few years of life. There was no clear interspecific trade-off between early reproduction and early survival. Reproductive senescence was evident in most species. Generation length, calculated as the mean age of fathers, was negatively correlated with the reproductive success of young males and positively with life expectancy of 3-year-olds, but not with early mortality. The main determinant of male reproductive success in polygynous ungulates is the ability to prevail against competing males. Consequently, the number and age structure of competitors should strongly affect an individual’s ability to reproduce, making classic trade-offs among life-history traits very context-dependent. Most fitness costs of reproduction in male ungulates likely arise from energy expenditure and injuries sustained while attempting to mate. Individual costs may be weakly correlated with fitness returns.

Reproductive success in wood bison (Bison bison athabascae) established using molecular techniques

2002 ◽  
Vol 80 (9) ◽  
pp. 1537-1548 ◽  
Author(s):  
Gregory A Wilson ◽  
Wes Olson ◽  
Curtis Strobeck
Keyword(s):  
Reproductive Success ◽  
National Park ◽  
Molecular Techniques ◽  
Bison Bison ◽  
Male Reproductive Success ◽  
Female Reproductive Success ◽  
Wood Bison ◽  
Low Levels ◽  
Elk Island National Park ◽  
Linear Regressions

In this study, we used 21 microsatellite loci to establish the reproductive success of the wood bison (Bison bison athabascae) population at Elk Island National Park, Alberta, Canada. Wood bison are considered threatened in Canada, and this population is currently used to found new populations. Despite the low levels of genetic variation in this population, we were able to establish paternity in 253 and maternity in 295 of the 317 calves born in Elk Island National Park over the 4-year study period. Roughly 40% of the mature males were reproductively successful each year. Mature males produced a mean of 3.8 offspring over the study period, with a range of 0–24. Each year, approximately 50–70% of the cows produced calves, with a mean of 2.7 over the study period. Multiple linear regressions were performed to determine the effects of age, mass, heterozygosity, prior success, and the year of conception on male and female reproductive success. Only mass and prior success were useful in predicting male reproductive success. Female reproductive success depended on age, mass, and prior success and was also affected by environmental differences between years. No evidence was found for inbreeding avoidance in wood bison.

scholarly journals Genetic coordination of sperm morphology and seminal fluid proteins promotes male reproductive success in Drosophila melanogaster

2021 ◽  
Author(s):  
Jake Galvin ◽  
Erica Larson ◽  
Sevan Yedigarian ◽  
Mohammad Rahman ◽  
Kirill Borziak ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Reproductive Success ◽  
Sperm Competition ◽  
Seminal Fluid ◽  
Fertilization Success ◽  
Male Reproductive Success ◽  
Sperm Length ◽  
Seminal Fluid Proteins ◽  
Female Remating ◽  
Paternity Success

Spermatozoal morphology is highly variable both among and within species and in ways that can significantly impact fertilization success. In Drosophila melanogaster, paternity success depends on sperm length of both competing males and length of the female's primary sperm storage organ. We found that genes upregulated in long sperm testes are enriched for lncRNAs and seminal fluid proteins (Sfps). Transferred in seminal fluid to the female during mating, Sfps are secreted by the male accessory glands (AG) and affect female remating rate, physiology, and behavior with concomitant advantages for male reproductive success. Despite being upregulated in long sperm testes, they have no known function in testis tissue. We found that Sex Peptide and ovulin (Acp26Aa) knockouts resulted in shorter sperm, suggesting that Sfps may regulate sperm length during spermatogenesis. However, knockout of AG function did not affect sperm length, suggesting that AG expression has no influence on spermatogenic processes. We also found that long sperm males are better able to delay female remating, suggesting higher Sfp expression in AG. These results might suggest that long sperm males have a double advantage in sperm competition by both delaying female remating, likely through transfer of more Sfps, and by resisting sperm displacement. However, we also found that this extra advantage does not necessarily translate to more progeny or higher paternity success. Thus, we found that multiple components of the ejaculate coordinate to promote male reproductive success at different stages of reproduction, but the realized fitness advantages in sperm competition are uncertain.

scholarly journals Variance in within-pair reproductive success influences the opportunity for selection annually and over the lifetimes of males in a multi-brooded songbird

2020 ◽  
Author(s):  
Ryan R. Germain ◽  
Michael T. Hallworth ◽  
Sara A. Kaiser ◽  
T. Scott Sillett ◽  
Michael S. Webster
Keyword(s):  
Reproductive Success ◽  
Reproductive Strategies ◽  
Male Reproduction ◽  
Lifetime Reproductive Success ◽  
Male Reproductive Success ◽  
Components Of Variance ◽  
Lifetime Fitness ◽  
Monogamous Species ◽  
Socially Monogamous ◽  
Opportunity For Selection

AbstractIn socially monogamous species, male reproductive success consists of ‘within-pair’ offspring produced with their socially-paired mate(s), and ‘extra-pair’ offspring produced with additional females throughout the population. Both reproductive pathways offer distinct opportunities for selection in wild populations, as each is composed of separate components of mate attraction, female fecundity, and paternity allocation. Identifying key sources of variance and covariance among these components is a crucial step towards understanding the reproductive strategies that males use to maximize fitness both annually and over their lifetimes. We use 16 years of complete reproductive data from a population of black-throated blue warblers (Setophaga caerulescens) to partition variance in male annual and lifetime reproductive success, and thereby identify if the opportunity for selection varies over the lifetimes of individual males and what reproductive strategies likely favor maximum lifetime fitness. The majority of variance in male reproduction was attributable to within-pair success, but the specific effects of individual components of variance differed between total annual and total lifetime reproductive success. Positive overall lifetime covariance between within-pair and extra-pair components indicates that males able to maximize within-pair success, particularly with double-brooding females, likely achieve higher overall lifetime fitness via both within-pair and extra-pair reproductive pathways.

Growth, mortality, and longevity of the Egyptian tortoise Testudo kleinmanni Lortet, 1883

2009 ◽  
Vol 55 (2) ◽  
pp. 133-147 ◽  
Author(s):  
Daniele Macale ◽  
Massimiliano Scalici ◽  
Alberto Venchi
Keyword(s):  
Reproductive Success ◽  
Growth Model ◽  
Reproductive Output ◽  
Growth Patterns ◽  
Male Reproductive Success ◽  
Population Status ◽  
Female Reproductive Success ◽  
Large Size ◽  
Threatened Taxa

Both demography and population regulation play an important role in the theory of sustainable exploitation and conservation of threatened taxa, such as terrestrial Chelonia. Here, we show and discuss some dynamic aspects of Testudo kleinmanni using modal progression analysis of length compositions. Although the Testudinata physiology is very different from that of fish, their growth model conforms to the Von Bertalanffy growth model. We observed a maximum of three age classes for both juveniles and females, and four classes for males. No appreciable between-sex differences were found in growth patterns, except for the diverse asymptotic length. Females should be subject to a strong sexual selection to quickly reach a large size in order to optimize lifetime reproductive output. The T. kleinmanni male size could be driven by predation escape and by easy accessibility to females, rather than by fighting for them. Thus, male reproductive success increases with the ability to fertilize females and female reproductive success increases with the ability to produce eggs, creating a large divergence in the context of selection between sexes. Different selective (synergetic or antagonistic) forces would appear to favor divergence in size between sexes. Additional properties found in the study regard the elevated mortality rate, probably also due to the human impact (poaching), and the relatively high longevity (26 and 22 years for females and males, respectively). Dynamics studies are useful for planning in situ activities of monitoring the population status, and could have a role in introducting programs and in control of reintroduced individuals during a restocking project.

scholarly journals Quantitative trait locus mapping of fitness-related traits in Drosophila melanogaster

2001 ◽  
Vol 77 (1) ◽  
pp. 107-116 ◽  
Author(s):  
M. L. WAYNE ◽  
J. B. HACKETT ◽  
C. L. DILDA ◽  
S. V. NUZHDIN ◽  
E. G. PASYUKOVA ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Body Size ◽  
Reproductive Success ◽  
Quantitative Trait ◽  
Recombinant Inbred Lines ◽  
Male Reproductive Success ◽  
Female Reproductive Success ◽  
Mapping Procedure ◽  
Ovariole Number ◽  
Early Fecundity

We examined the genetic architecture of four fitness-related traits (reproductive success, ovariole number, body size and early fecundity) in a panel of 98 Oregon-R × 2b3 recombinant inbred lines (RILs). Highly significant genetic variation was observed in this population for female, but not male, reproductive success. The cross-sex genetic correlation for reproductive success was 0·20, which is not significantly different from zero. There was significant genetic variation segregating in this cross for ovariole number, but not for body size or early fecundity. The RILs were genotyped for cytological insertion sites of roo transposable elements, yielding 76 informative markers with an average spacing of 3·2 cM. Quantitative trait loci (QTL) affecting female reproductive success and ovariole number were mapped using a composite interval mapping procedure. QTL for female reproductive success were located at the tip of the X chromosome between markers at cytological locations 1B and 3E; and on the left arm of chromosome 2 in the 30D–38A cytological region. Ovariole number QTL mapped to cytological intervals 62D–69D and 98A–98E, both on the third chromosome. The regions harbouring QTL for female reproductive success and ovariole number were also identified as QTL for longevity in previous studies with these lines.

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