scholarly journals Can paternal effects via seminal fluid contribute to the evolution of polyandry?

2020 ◽  
Vol 16 (11) ◽  
pp. 20200680
Author(s):  
Leigh W. Simmons ◽  
Maxine Lovegrove

Genetic benefits from mating with multiple males are thought to favour the evolution of polyandry. However, recent evidence suggests that non-genetic paternal effects via seminal fluid might contribute to the observed effects of polyandry on offspring performance. Here, we test this hypothesis using the field cricket Teleogryllus oceanicus . Using interference RNA, we first show that at least one seminal fluid protein is essential for embryo survival. We then show that polyandrous females mated to three different males produced embryos with higher pre-hatching viability than did monandrous females mated with the same male three times. Pseudo-polyandrous females that obtained sperm and seminal fluid from a single male and seminal fluid from two additional males had embryos with viabilities intermediate between monandrous and polyandrous females. Our results suggest either that ejaculate mediated paternal effects on embryo viability have both genetic and non-genetic components, or that seminal fluids transferred by castrated males provide only a subset of proteins contained within the normal ejaculate, and are unable to exert their full effect on embryo viability.

2019 ◽  
Vol 47 (1) ◽  
Author(s):  
Lain Uriel Ohlweiler ◽  
Joana Claudia Mezzalira ◽  
Alceu Mezzalira

Background: Porcine embryos are sensible to all assisted reproduction manipulations, especially the ones that involve cryopreservation. Despite the high cryoprotectant concentrations routinely applied, vitrification is the most effective technique to date. These substances toxicity can also play a negative role in embryo viability. During in vitro porcine embryo production, the speed of development is often unevenly distributed. It is possible that their development speed, affects embryo tolerance to cryoprotectants. This study aimed to evaluate the toxicity of porcine embryos of days 5 or 6 of culture to cryoprotectant agents; as well as to assess embryo survival to vitrification.Material, Methods & Results: Parthenogenetic porcine blastocysts and expanded blastocysts of days 5 and 6 of culture were exposed to toxicity tests (experiments 1 and 2) and vitrification (experiment 3) using different protocols. In the first experiment, three different cryoprotectants were used (Dimethyl sulfoxide - DMSO, Ethylene glycol – EG, and Sucrose - SUC), combined in three different associations (G1: 15% EG + 15% DMSO with 0.5M SUC; G2: 16% EG + 16% DMSO with 0.4M SUC; G3: 18% EG + 18% DMSO with 0.5M SUC). In the fresh Control, embryos of day 6 are more sensible than the ones of day 5, whom showed a lower hatching rate (39.7 vs. 60.8%). After the toxicity (Experiment 1) test, the G1 showed better expansion rates in day 6 (50.0 vs 31.0 and 3.6% for G2 and G3) and higher hatching of day 6 compared to G2 and G3 (23.2, vs. 8.6 and 0.0% for G2 and G3). The fresh non hatched embryos at day 8, derived at day 6, had a lower percentage of cells with cleaved caspase-3 (20.2%) compared with the G1 (30.5%), G2 (31.4%) and G3 (30.5%). The hatched embryos of day 5 from G2 had lower total cell number (TCN) compared with the day 6 hatched embryos, whereas in G1 the TCN was not affected. The second experiment compared EG combined to one of these three extracellular cryoprotectants: Polyvinylpyrrolidone/sucrose/trehalose (respectively groups: PVP, SUC, TRE). The group SUC has raised the best results for day 5 embryos, whereas for day 6 embryos SUC and TRE were both best. The third experiment tested four vitrification protocols, being P1: EG+DMSO+TRE/warming with SUC; P2: EG+DMSO+TRE/warming TRE; P3: EG+TRE/ warming SUC; P4: EG+TRE/warming TRE. The expansion of vitrified day 5 embryos was higher in the P1 (20.0%) in comparison with the other three groups (4.3, 4.3 and 4.4% for P2, P3 and P4, respectively), with no difference for their hatching rates, been it lower comparing to the Control. Day 6 embryos showed no difference in expansion and hatching for the vitrified groups, been them lower than the Control.Discussion: Embryos obtained on day 6 are more sensible than the ones of day 5, fact observed when the embryos were exposed to cryoprotectant solution, as well by the behavior of the no treated Control embryos. The toxicity increases as it does the concentration of intracellular cryoprotectant, where over 16% of the intracellular cryoprotectors already affected the day 6 embryos development. For the day 5 embryos however, 15 or 16% of the intracellular cryoptrotectors, had similar behavior to the embryos. For the extracellular solutions, however, it is variable according the embryos development speed. Indeed, it is necessary to adjust the cryoprotectors to be used to cryopreserve porcine in vitro produced embryos obtained at days 5 and 6 of culture.


2019 ◽  
Vol 31 (1) ◽  
pp. 82 ◽  
Author(s):  
José-Alfonso Abecia ◽  
Fernando Forcada ◽  
María-Isabel Vázquez ◽  
Teresa Muiño-Blanco ◽  
José A. Cebrián-Pérez ◽  
...  

Melatonin is a natural hormone synthesised in the pineal gland, the activity of which is regulated by day–night perception and dictates seasonal rhythms in reproduction in ovine species. Exogenous melatonin, administered via subcutaneous implants, is used to prolong the breeding season of ewes and can increase the proportion of pregnant ewes (fertility rate) and litter size. The increased proportion of ewes that become pregnant and the number of lambs born per lambing among melatonin-treated sheep may be caused by increased embryo survival, through enhanced luteal function, reduced antiluteolytic mechanisms, or improved embryo quality. This review focuses on the effects of melatonin on embryo viability and summarises the processes by which this hormone affects the ovary, follicle, oocyte, corpus luteum and embryo. Moreover, the effects of melatonin on the mechanisms of invivo maternal recognition of pregnancy in sheep and the protective action that it appears to have on the invitro procedures that are used to obtain healthy embryos are reviewed.


2019 ◽  
Vol 116 (17) ◽  
pp. 8437-8444 ◽  
Author(s):  
Brian Hollis ◽  
Mareike Koppik ◽  
Kristina U. Wensing ◽  
Hanna Ruhmann ◽  
Eléonore Genzoni ◽  
...  

In many animals, females respond to mating with changes in physiology and behavior that are triggered by molecules transferred by males during mating. InDrosophila melanogaster, proteins in the seminal fluid are responsible for important female postmating responses, including temporal changes in egg production, elevated feeding rates and activity levels, reduced sexual receptivity, and activation of the immune system. It is unclear to what extent these changes are mutually beneficial to females and males or instead represent male manipulation. Here we use an experimental evolution approach in which females are randomly paired with a single male each generation, eliminating any opportunity for competition for mates or mate choice and thereby aligning the evolutionary interests of the sexes. After >150 generations of evolution, males from monogamous populations elicited a weaker postmating stimulation of egg production and activity than males from control populations that evolved with a polygamous mating system. Males from monogamous populations did not differ from males from polygamous populations in their ability to induce refractoriness to remating in females, but they were inferior to polygamous males in sperm competition. Mating-responsive genes in both the female abdomen and head showed a dampened response to mating with males from monogamous populations. Males from monogamous populations also exhibited lower expression of genes encoding seminal fluid proteins, which mediate the female response to mating. Together, these results demonstrate that the female postmating response, and the male molecules involved in eliciting this response, are shaped by ongoing sexual conflict.


Ecology ◽  
2013 ◽  
Vol 94 (11) ◽  
pp. 2575-2582 ◽  
Author(s):  
Angela J. Crean ◽  
John M. Dwyer ◽  
Dustin J. Marshall

2014 ◽  
Vol 281 (1785) ◽  
pp. 20140422 ◽  
Author(s):  
Susanne Zajitschek ◽  
Cosima Hotzy ◽  
Felix Zajitschek ◽  
Simone Immler

The inheritance of non-genetic factors is increasingly seen to play a major role in ecology and evolution. While the causes and consequences of epigenetic effects transmitted from the mother to the offspring have received ample attention, much less is known about how variation in the condition of the father affects the offspring. Here, we manipulated the intensity of sperm competition experienced by male zebrafish Danio rerio to investigate the potential for sperm-mediated epigenetic effects over a relatively short period of time. We found that the rapid responses of males to varying intensity of sperm competition not only affected sperm traits as shown previously, but also the performance of the resulting offspring. We observed that males exposed to high intensity of sperm competition produced faster swimming and more motile sperm, and sired offspring that hatched over a narrower time frame but exhibited a lower survival rate than males exposed to low intensity of sperm competition. Our results provide striking evidence for short-term paternal effects and the possible fitness consequences of such sperm-mediated non-genetic factors not only for the resulting offspring but also for the female.


2007 ◽  
Vol 19 (3) ◽  
pp. 430 ◽  
Author(s):  
M. D. Vinsky ◽  
G. K. Murdoch ◽  
W. T. Dixon ◽  
M. K. Dyck ◽  
G. R. Foxcroft

Feed restriction of primiparous sows during the last week of lactation has been shown to decrease embryonic growth and female embryo survival to Day 30 of gestation. This study sought to determine whether global DNA methylation and epigenetic gene expression of the candidate genes Igf2, Igf2r, and Xist were associated with these treatment effects. Given that these epigenetic traits are expected to be important for embryo viability, changes in variance for these traits at Day 30 were predicted to be reflected in the loss of abnormal embryos at this time. Consistent with this prediction, variance in DNA methylation was reduced (P < 0.001) in Restrict male embryo, and there was a tendency for reduced variance (P < 0.06) in Restrict female embryos. Variation in DNA methylation tended to be correlated (R = 0.42, P < 0.1) with the difference in variance of embryo weights between treatments (P < 0.01), suggesting a relationship between epigenetic changes and embryonic development. Variance in Igf2r expression tended to decrease (P < 0.07) in Restrict female embryos while variance in Xist expression tended to decrease in Restrict male embryos (P < 0.08), suggesting that maternally inherited epigenetic defects may cause female embryonic loss and reduced growth before Day 30 of gestation.


Reproduction ◽  
2019 ◽  
Vol 157 (4) ◽  
pp. R109-R126 ◽  
Author(s):  
Jonathan P Evans ◽  
Alastair J Wilson ◽  
Andrea Pilastro ◽  
Francisco Garcia-Gonzalez

Despite serving the primary objective of ensuring that at least one sperm cell reaches and fertilises an ovum, the male ejaculate (i.e. spermatozoa and seminal fluid) is a compositionally complex ‘trait’ that can respond phenotypically to subtle changes in conditions. In particular, recent research has shown that environmentally and genetically induced changes to ejaculates can have implications for offspring traits that are independent of the DNA sequence encoded into the sperm’s haploid genome. In this review, we compile evidence from several disciplines and numerous taxonomic systems to reveal the extent of such ejaculate-mediated paternal effects (EMPEs). We consider a number of environmental and genetic factors that have been shown to impact offspring phenotypes via ejaculates, and where possible, we highlight the putative mechanistic pathways by which ejaculates can act as conduits for paternal effects. We also highlight how females themselves can influence EMPEs, and in some cases, how maternally derived sources of variance may confound attempts to test for EMPEs. Finally, we consider a range of putative evolutionary implications of EMPEs and suggest a number of potentially useful approaches for exploring these further. Overall, our review confirms that EMPEs are both widespread and varied in their effects, although studies reporting their evolutionary effects are still in their infancy.


2004 ◽  
Vol 16 (2) ◽  
pp. 172 ◽  
Author(s):  
J.M. Kelly ◽  
D.O. Kleemann ◽  
M. Kuwayama ◽  
S.K. Walker

Considerable progress has been achieved in the cryopreservation of mammalian embryos. The use of vitrification minimizes chilling injuries by increasing cooling and warming rates. This study assesses the effect of vitrification using the minimum volume cooling (MVC) method (Kuwayama &amp; Kato 2000 J. Assist. Reprod. Genet. 17, 477) on in vitro-produced bovine and ovine embryos. A total of 1756 ovine and 753 bovine cumulus-oocyte complexes were obtained from the abattoir and matured, fertilized (Day 0) and cultured in vitro (Walker et al., 1996 Biol. Reprod. 55, 703–708, Kelly et al., 1997 Theriogenology 47, 291). Overall cleavage rates were 93.7% and 80.5% respectively. Embryos were vitrified (OPS or MVC method) on Days 5 (morula, compact morula), 6 (expanded blastocyst, blastocyst, compact morula) or 7 (hatched and hatching blastocysts, expanded blastocyst, blastocyst). Embryos were equilibrated with 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for 3min and then exposed to 16.5% EG, 16.5% DMSO, 0.5M sucrose and 20% FCS for 30s. Embryos were loaded onto either an MVC plate (Cryotop, Kitazato Supply Co, Toyko, Japan) or open pulled straw (OPS) and plunged into liquid nitrogen. After 5 days, embryos were thawed directly into 1.25M sucrose solution at 38.5°C, followed by stepwise dilution of the cryoprotectants. Embryo survival was assessed by culture to Day 8 and compared to the development of non-vitrified control embryos (Table 1). Variables were assessed using procedure CATMOD in SAS. The Cryotop method yielded a significantly higher percentage of viable ovine embryos after thawing compared with OPS (P&lt;0.0001); neither day nor treatment x day interaction was significant (P&gt;0.05). A significant interaction between vitrification treatment and day (P&lt;0.007) indicated that the percentage of hatched embryos peaked at Day 6 using the Cryotop method compared with Day 7 for OPS. Hatching rates for fresh and vitrified embryos were similar at Day 7 and were independent of treatment. With the Cryotop method, day of vitrification did not influence the percentage of Days 6 and 7 bovine embryos that hatched after thawing but, on each day, this figure was significantly higher (P&lt;0.003 and P&lt;0.0001, respectively) than that obtained with fresh embryos. To further assess embryo viability, 36 fresh, 52 OPS and 56 Cryotop vitrified Day-6 in vitro-produced ovine embryos were transferred to synchronized recipients. Survival rates to Day 13 were 29/33 (87.9%), 23/36 (63.9%) and 42/51 (82.4%), respectively (P&lt;0.05). This study demonstrates that using the MVC Cryotop method, the viability of vitrified embryos, as assessed at Days 8 and 13, is similar to that obtained with fresh embryos. Table 1


2011 ◽  
Vol 278 (1717) ◽  
pp. 2495-2501 ◽  
Author(s):  
Clelia Gasparini ◽  
Andrea Pilastro

As inbreeding is costly, it has been suggested that polyandry may evolve as a means to reduce the negative fitness consequences of mating with genetically related males. While several studies provide support for this hypothesis, evidence of pure post-copulatory mechanisms capable of biasing paternity towards genetically unrelated males is still lacking; yet these are necessary to support inbreeding avoidance models of polyandry evolution. Here we showed, by artificially inseminating a group of female guppies with an equal number of sperm from related (full-sib) and unrelated males, that sperm competition success of the former was 10 per cent lower, on average, than that of the unrelated male. The paternity bias towards unrelated males was not due to differential embryo survival, as the size of the brood produced by control females, which were artificially inseminated with the sperm of a single male, was not influenced by their relatedness with the male. Finally, we collected ovarian fluid (OF) from virgin females. Using computer-assisted sperm analysis, we found that sperm velocity, a predictor of sperm competition success in the guppy, was significantly lower when measured in a solution containing the OF from a sister as compared with that from an unrelated female. Our results suggest that sperm–OF interaction mediates sperm competition bias towards unrelated mates and highlight the role of post-copulatory mechanisms in reducing the cost of mating with relatives in polyandrous females.


2007 ◽  
Vol 3 (4) ◽  
pp. 379-381 ◽  
Author(s):  
William E Wagner ◽  
Andrew R Smith ◽  
Alexandra L Basolo

Females commonly prefer to mate with males that provide greater material benefits, which they often select using correlated male signals. When females select higher-benefit males based on correlated signals, however, males can potentially deceive females by producing exaggerated signals of benefit quality. The handicap mechanism can prevent lower-quality males from producing exaggerated signals, but cannot prevent cheating by higher-quality males that choose to withhold the benefit, and this poses a major problem for the evolution of female choice based on direct benefits. In a field cricket, Gryllus lineaticeps , females receive seminal fluid products from males with preferred songs that increase their fecundity and lifespan. We tested the hypothesis that female behaviour penalizes males that provide lower-quality benefits. When females were paired with males that varied in benefit quality but had experimentally imposed average songs, they were less likely to re-mate with males that provided lower-quality benefits in the initial mating. This type of conditional female re-mating may be a widespread mechanism that penalizes males that cheat on direct benefits.


Sign in / Sign up

Export Citation Format

Share Document