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Functional Ecology Mar 2016Males of many species fine-tune their ejaculates in response to sperm competition risk. Resource availability and the number of competitors during development can also...
Males of many species fine-tune their ejaculates in response to sperm competition risk. Resource availability and the number of competitors during development can also strongly influence sperm production. However, despite the key role of seminal proteins in mediating reproductive processes, it is unclear whether seminal protein investment is dependent on the developmental environment.We manipulated the developmental environment of by rearing flies at low and high density. As expected, this resulted in large and small (i.e. high and low condition) adult phenotypes, respectively.As predicted, large males produced more of two key seminal proteins, sex peptide (SP) and ovulin, and were more successful at obtaining matings with both virgin and previously mated females. However, there was only a weak and non-significant trend for large males to transfer more absolute quantities of SP at mating, and thus, small males ejaculated proportionally more of their stored accessory gland SP resources.Males transferred more receptivity-inhibiting SP to large females. Despite this, large females remated more quickly than small females and thus responded to their developmental environment over and above the quantity of SP they received.The results are consistent with two non-mutually exclusive hypotheses. First, flies might respond to condition-dependent reproductive opportunities, with (i) small males investing heavily in ejaculates when mating opportunities arise and large males strategically partitioning SP resources and (ii) small females remating at reduced rates because they have higher mating costs or need to replenish sperm less often.Second, flies may be primed by their larval environment to deal with similar adult population densities, with (i) males perceiving high density as signalling increased competition, leading small males to invest proportionally more SP resources at mating and (ii) females perceiving high density as signalling abundant potential mates, leading to a higher sexual receptivity threshold.Thus, by influencing the mating frequencies of both sexes, as well as the quantity of seminal proteins produced by males and received by females, the developmental environment is likely to have far-reaching and sex-specific consequences for sexual selection and sexual conflict.
PubMed: 27546947
DOI: 10.1111/1365-2435.12515 -
Journal of Medical Entomology Mar 2011Male reproductive success is dependent on insemination success and reproductive output. During mating, male mosquitoes transfer not just sperm, but also seminal fluid...
Male reproductive success is dependent on insemination success and reproductive output. During mating, male mosquitoes transfer not just sperm, but also seminal fluid proteins that may have profound effects on mated female biology and behavior. In this study, we investigated the role of male body size and mating history on semen depletion, female longevity, and reproductive success in Aedes aegypti L. Small and large males were mated in rapid succession with up to five females. Our results indicate that large males had greater mating capacity than small males. A reduction in fecundity by >50% was observed in females that were fourth to mate with small males in comparison with females that mated earlier in sequence. For females mated to large males, this reduction became evident for females that mated fifth in sequence. No loss of fertility (measured as hatch rate) was observed in females that were third-fifth in mating sequence compared with females mated to virgin males. When females were maintained on a low-quality (5% sucrose) diet, those mated to virgin males had a greater longevity compared with females mated third in sequence. We conclude that small males experience more rapid seminal depletion than large males, and discuss the role of semen depletion in the mated female. Our results contribute toward a better understanding of the complexity of Ae. aegypti mating biology and provide refined estimates of mating capacity for genetic control efforts.
Topics: Aedes; Animals; Blood; Body Size; Carbohydrates; Dengue; Female; Humans; Insect Vectors; Larva; Longevity; Male; Reproduction; Semen
PubMed: 21485355
DOI: 10.1603/me10071 -
Proceedings. Biological Sciences Dec 2010Post-mating reduction in immune defence is common in female insects, and a trade-off between mating and immunity could affect the evolution of immunity. In this work, we...
Post-mating reduction in immune defence is common in female insects, and a trade-off between mating and immunity could affect the evolution of immunity. In this work, we tested the capacity of virgin and mated female Drosophila melanogaster to defend against infection by four bacterial pathogens. We found that female D. melanogaster suffer post-mating immunosuppression in a pathogen-dependent manner. The effect of mating was seen after infection with two bacterial pathogens (Providencia rettgeri and Providencia alcalifaciens), though not after infection with two other bacteria (Enterococcus faecalis and Pseudomonas aeruginosa). We then asked whether the evolution of post-mating immunosuppression is primarily a 'female' or 'male' trait by assaying for genetic variation among females for the degree of post-mating immune suppression they experience and among males for the level of post-mating immunosuppression they elicit in their mates. We also assayed for an interaction between male and female genotypes to test the specific hypothesis that the evolution of a trade-off between mating and immune defence in females might be being driven by sexual conflict. We found that females, but not males, harbour significant genetic variation for post-mating immunosuppression, and we did not detect an interaction between female and male genotypes. We thus conclude that post-mating immune depression is predominantly a 'female' trait, and find no evidence that it is evolving under sexual conflict.
Topics: Animals; Drosophila melanogaster; Enterococcus faecalis; Female; Genetic Variation; Immunity, Innate; Immunosuppression Therapy; Male; Providencia; Pseudomonas aeruginosa; Reproduction; Sex Characteristics; Sexual Behavior, Animal
PubMed: 20573620
DOI: 10.1098/rspb.2010.0937 -
Frontiers in Cell and Developmental... 2021Reproduction comes at a cost, including accelerated death. Previous studies of the interconnections between reproduction, lifespan, and fat metabolism in were...
Reproduction comes at a cost, including accelerated death. Previous studies of the interconnections between reproduction, lifespan, and fat metabolism in were predominantly performed in low-reproduction conditions. To understand how increased reproduction affects lifespan and fat metabolism, we examined mated worms; we find that a Δ9 desaturase, FAT-7, is significantly up-regulated. Dietary supplementation of oleic acid (OA), the immediate downstream product of FAT-7 activity, restores fat storage and completely rescues mating-induced death, while other fatty acids cannot. OA-mediated lifespan restoration is also observed in mutants suffering increased death from short-term mating, and in mated females, indicating a conserved role of oleic acid in post-mating lifespan regulation. Our results suggest that increased reproduction can be uncoupled from the costs of reproduction from somatic longevity regulation if provided with the limiting lipid, oleic acid.
PubMed: 34179018
DOI: 10.3389/fcell.2021.690373 -
Neurochemical Research Jun 2019Sleep is a highly conserved state in animals, but its regulation and physiological function is poorly understood. Drosophila melanogaster is an excellent model for...
Sleep is a highly conserved state in animals, but its regulation and physiological function is poorly understood. Drosophila melanogaster is an excellent model for studying sleep regulation and has been used to investigate how sex and social interactions can influence wake-sleep profiles. Previously we have shown that copulation has a profound effect on day time activity and quiescence (siesta sleep) of individual post-mated females. Here we have the studied the effect of mating and the transfer of the 36 amino acid sex peptide in the seminal fluid on the behavior of mated female Drosophila populations, where there will be on-going social interactions. The locomotor activity and sleep patterns of virgin and post-mated female D. melanogaster from three laboratory strains (Oregon-R, Canton-S and Dahomey) were recorded in social groups of 20 individuals in a 12-12 h light-dark cycle. Virgin female populations from all three fly strains displayed consolidated periods of low activity in between two sharp peaks of activity, corresponding to lights-on and lights-off. Similar light-correlated peaks were recorded for the mated female populations, however, the low afternoon activity and siesta seen in virgin populations was abolished after mating in all three strains. In contrast, night activity appeared unaffected. This post-mating effect was sustained for several days and was dependent on the male SP acting as a pheromone. Evidence from mixed populations of virgin and mated females suggests that the siesta of non-mated females is not easily disturbed by the presence of highly active post-mated females.
Topics: Animals; Behavior, Animal; Circadian Rhythm; Copulation; Drosophila Proteins; Drosophila melanogaster; Female; Intercellular Signaling Peptides and Proteins; Locomotion; Male; Peptides; Sleep; Social Behavior
PubMed: 30661229
DOI: 10.1007/s11064-019-02722-7 -
BMC Microbiology May 2020Conjugation plays a major role in the transmission of plasmids encoding antibiotic resistance genes in both clinical and general settings. The conjugation efficiency is... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Conjugation plays a major role in the transmission of plasmids encoding antibiotic resistance genes in both clinical and general settings. The conjugation efficiency is influenced by many biotic and abiotic factors, one of which is the taxonomic relatedness between donor and recipient bacteria. A comprehensive overview of the influence of donor-recipient relatedness on conjugation is still lacking, but such an overview is important to quantitatively assess the risk of plasmid transfer and the effect of interventions which limit the spread of antibiotic resistance, and to obtain parameter values for conjugation in mathematical models. Therefore, we performed a meta-analysis on reported conjugation frequencies from Escherichia coli donors to various recipient species.
RESULTS
Thirty-two studies reporting 313 conjugation frequencies for liquid broth matings and 270 conjugation frequencies for filter matings were included in our meta-analysis. The reported conjugation frequencies varied over 11 orders of magnitude. Decreasing taxonomic relatedness between donor and recipient bacteria, when adjusted for confounding factors, was associated with a lower conjugation frequency in liquid matings. The mean conjugation frequency for bacteria of the same order, the same class, and other classes was 10, 20, and 789 times lower than the mean conjugation frequency within the same species, respectively. This association between relatedness and conjugation frequency was not found for filter matings. The conjugation frequency was furthermore found to be influenced by temperature in both types of mating experiments, and in addition by plasmid incompatibility group in liquid matings, and by recipient origin and mating time in filter matings.
CONCLUSIONS
In our meta-analysis, taxonomic relatedness is limiting conjugation in liquid matings, but not in filter matings, suggesting that taxonomic relatedness is not a limiting factor for conjugation in environments where bacteria are fixed in space.
Topics: Bacteria; Bacterial Physiological Phenomena; Conjugation, Genetic; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Proteins; Phylogeny; Plasmids; Species Specificity
PubMed: 32456625
DOI: 10.1186/s12866-020-01825-4 -
Royal Society Open Science Apr 2024In species where females compete for mates, the male often provides the female with resources in addition to gametes. A recently suggested definition of sexual selection...
In species where females compete for mates, the male often provides the female with resources in addition to gametes. A recently suggested definition of sexual selection proposed that if females only benefit from additional resources that come with each mating and not additional gametes, female intrasexual competition for mating opportunities would result in natural selection rather than sexual selection. The nuptial gift-giving bushcricket has dynamic sex roles and has been a textbook example of sexual selection acting on females via mating competition. We investigated whether females of this species gain fitness benefits from nuptial gifts, additional ejaculates or both by controlling the number of matings and whether the female was allowed to consume the nutritious gift (spermatophylax) at mating. We found that egg production per day of life increased with the number of additional matings, both with and without spermatophylax consumption, but consuming the spermatophylax had an additional positive effect on the number of eggs. These effects were particularly strong in females with shorter lifespans. We discuss how the recently suggested definition of sexual selection applies to nuptial-feeding insects and conclude that both natural and sexual selections influence mating competition in females.
PubMed: 38586425
DOI: 10.1098/rsos.240191 -
Genome Biology and Evolution Jan 2018Female post-mating behaviors are regulated by complex factors involving males, females, and the environment. In insects, plant secondary compounds that males actively...
Female post-mating behaviors are regulated by complex factors involving males, females, and the environment. In insects, plant secondary compounds that males actively forage for, may indirectly modify female behaviors by altering male behavior and physiology. In the tephritid fruit fly, Bactrocera tryoni, females mated with males previously fed on plant-derived phenylpropanoids (="lures" based on usage in tephritid literature), have longer mating refractoriness, greater fecundity, and reduced longevity than females mated with non-lure fed males. This system thus provides a model for studying transcriptional changes associated with those post-mating behaviors, as the genes regulating the phenotypic changes are likely to be expressed at a greater magnitude than in control females. We performed comparative transcriptome analyses using virgin B. tryoni females, females mated with control males (control-mated), and females mated with lure-fed males (lure-mated). We found 331 differentially expressed genes (DEGs) in control-mated females and 80 additional DEGs in lure-mated females. Although DEGs in control-mated females are mostly immune response genes and chorion proteins, as reported in Drosophila species, DEGs in lure-mated females are titin-like muscle proteins, histones, sperm, and testis expressed proteins which have not been previously reported. While transcripts regulating mating (e.g., lingerer) did not show differential expression in either of the mated female classes, the odorant binding protein Obp56a was down-regulated. The exclusively enriched or suppressed genes in lure-mated females, novel transcripts such as titin and histones, and several taxa-specific transcripts reported here can shed more light on post-mating transcriptional changes, and this can help understand factors possibly regulating female post-mating behaviors.
Topics: Animals; Female; Fertility; Gene Ontology; Herbivory; Male; Plants; Reproduction; Sexual Behavior, Animal; Tephritidae; Transcriptome
PubMed: 29220418
DOI: 10.1093/gbe/evx257 -
Proceedings of the National Academy of... Mar 2000Young mated male Caribbean fruit flies [Anastrepha suspensa (Loew)] have greater sexual prowess than their virgin counterparts. After mating for the first time, 6- to...
Young mated male Caribbean fruit flies [Anastrepha suspensa (Loew)] have greater sexual prowess than their virgin counterparts. After mating for the first time, 6- to 7-day-old males released twice as much sex pheromone and acquired another mate in less than half the time required by virgin males of the same age. Mass spectroscopic analysis of extracts of hemolymph from mated and virgin 7-day-old males resulted in identification of juvenile hormone III bisepoxide and juvenile hormone III in a ratio of 2.5:1. Extracts from mated males contained 3-fold more juvenile hormone than did extracts from virgins. Enhancement of sexual signaling, pheromone release, and mating was induced by topical application of juvenile hormone, methoprene, or fenoxycarb. Newly eclosed adult males treated with juvenoids engaged in sexual signaling, released pheromone, and mated at significantly earlier ages than control males. We conclude that juvenile hormone mediated a positive feedback system that imparted a competitive advantage, guaranteeing that males who mated at an early age would out-compete virgins of the same age for mating opportunities. Additionally, the results support the hypothesis that juvenile hormone is a pivotal hormone coordinating the development of sexual signaling and reproductive maturity in these flies.
Topics: Animals; Diptera; Juvenile Hormones; Male; Reproduction; Sex Attractants; Sexual Behavior, Animal; Signal Transduction
PubMed: 10706642
DOI: 10.1073/pnas.97.7.3708 -
PloS One 2011Interspecific reproductive isolation is typically achieved by a combination of intrinsic and extrinsic barriers. Behavioural isolating barriers between sympatric,...
BACKGROUND
Interspecific reproductive isolation is typically achieved by a combination of intrinsic and extrinsic barriers. Behavioural isolating barriers between sympatric, closely related species are often of primary importance and frequently aided by extrinsic factors causing spatial and temporal interspecific separation. Study systems with a severely limited role of extrinsic factors on reproductive isolation may provide valuable insights into how reproductive isolation between sympatric species is maintained. We used no-choice experimental set-up to study reproductive barriers between two closely related sympatric African killifish species, Nothobranchius furzeri and Nothobranchius orthonotus. These fish live in small temporary savannah pools and have complete spatial and temporal overlap in reproductive activities and share a similar ecology.
PRINCIPAL FINDINGS
We found that the two species display largely incomplete and asymmetric reproductive isolation. Mating between N. furzeri males and N. orthonotus females was absent under standard experimental conditions and eggs were not viable when fish were forced to mate in a modified experimental setup. In contrast, male N. orthonotus indiscriminately mated with N. furzeri females, the eggs were viable, and offspring successfully hatched. Most spawnings, however, were achieved by male coercion and egg production and embryo survival were low. Behavioural asymmetry was likely facilitated by mating coercion from larger males of N. orthonotus and at relatively low cost to females. Interestingly, the direction of asymmetry was positively associated with asymmetry in post-mating reproductive barriers.
SIGNIFICANCE
We showed that, in fish species with a promiscuous mating system and multiple matings each day, selection for strong mate preferences was relaxed. This effect was likely due to the small proportion of resources allocated to each single mating and the high potential cost to females from mating refusal. We highlight and discuss the fact that males of rarer species may often coercively mate with females of a related, more abundant species.
Topics: Animals; Female; Fundulidae; Male; Reproduction; Sexual Behavior, Animal
PubMed: 21850233
DOI: 10.1371/journal.pone.0022684