1
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Liao A, Cavigliasso F, Savary L, Kawecki TJ. Effects of an entomopathogenic fungus on the reproductive potential of Drosophila males. Ecol Evol 2024; 14:e11242. [PMID: 38590549 PMCID: PMC10999951 DOI: 10.1002/ece3.11242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/10/2024] Open
Abstract
While mortality is often the primary focus of pathogen virulence, non-lethal consequences, particularly for male reproductive fitness, are less understood; however, they are essential for understanding how sexual selection contributes to promoting resistance. We investigated how the fungal pathogen Metarhizium brunneum affects mating ability, fertility, and seminal fluid protein (SFP) expression of male Drosophila melanogaster paired with highly receptive virgin females in non-competitive settings. Depending on sex and dose, there was a 3-6-day incubation period after infection, followed by an abrupt onset of mortality. Meanwhile, the immune response was strongly induced already 38 h after infection and continued to increase as infection progressed. Latency to mate somewhat increased during the incubation period compared to sham-treated males, but even on Day 5 post infection >90% of infected males mated within 2 h. During the incubation period, M. brunneum infection reduced male reproductive potential (the number of offspring sired without mate limitation) by 11%, with no clear increase over time. Approaching the end of the incubation period, infected males had lower ability to convert number of mating opportunities into number of offspring. After repeated mating, infected males had lower SFP expression than sham controls, more so in males that mated with few mates 24 h earlier. Overall, despite strong activation of the immune response, males' mating ability and fertility remained surprisingly little affected by the fungal infection, even shortly before the onset of mortality. This suggests that the selection for resistance acts mainly through mortality, and the scope for fertility selection to enhance resistance in non-competing settings is rather limited.
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Affiliation(s)
- Aijuan Liao
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Fanny Cavigliasso
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Loriane Savary
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Tadeusz J. Kawecki
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
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2
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Patlar B, Fulham L, Civetta A. A predominant role of genotypic variation in both expression of sperm competition genes and paternity success in Drosophila melanogaster. Proc Biol Sci 2023; 290:20231715. [PMID: 37727083 PMCID: PMC10509582 DOI: 10.1098/rspb.2023.1715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 08/25/2023] [Indexed: 09/21/2023] Open
Abstract
Sperm competition is a crucial aspect of male reproductive success in many species, including Drosophila melanogaster, and seminal fluid proteins (Sfps) can influence sperm competitiveness. However, the combined effect of environmental and genotypic variation on sperm competition gene expression remains poorly understood. Here, we used Drosophila Genetic Reference Panel (DGRP) inbred lines and manipulated developmental population density (i.e. larval density) to test the effects of genotype, environment and genotype-by-environment interactions (GEI) on the expression of the known sperm competition genes Sex Peptide, Acp36DE and CG9997. High larval density resulted in reduced adult body size, but expression of sperm competition genes remained unaffected. Furthermore, we found no significant GEI but genotypic effects in the expression of SP and Acp36DE. Our results also revealed GEI for relative competitive paternity success (second male paternity; P2), with genes' expression positively correlated with P2. Given the effect of genotype on the expression of genes, we conducted a genome-wide association study (GWAS) and identified polymorphisms in putative cis-regulatory elements as predominant factors regulating the expression of SP and Acp36DE. The association of genotypic variation with sperm competition outcomes, and the resilience of sperm competition genes' expression against environmental challenges, demonstrates the importance of genome variation background in reproductive fitness.
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Affiliation(s)
- Bahar Patlar
- Department of Biology, University of Winnipeg, Winnipeg, Manitoba, Canada R3B 2E9
| | - Lauren Fulham
- Department of Biology, University of Winnipeg, Winnipeg, Manitoba, Canada R3B 2E9
| | - Alberto Civetta
- Department of Biology, University of Winnipeg, Winnipeg, Manitoba, Canada R3B 2E9
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3
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Guan GX, Yu XP, Li DT. Post-Mating Responses in Insects Induced by Seminal Fluid Proteins and Octopamine. BIOLOGY 2023; 12:1283. [PMID: 37886993 PMCID: PMC10604773 DOI: 10.3390/biology12101283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/23/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023]
Abstract
Following insect mating, females often exhibit a series of physiological, behavioral, and gene expression changes. These post-mating responses (PMRs) are induced by seminal fluid components other than sperm, which not only form network proteins to assist sperm localization, supplement female-specific protein requirements, and facilitate the formation of specialized functional structures, but also activate neuronal signaling pathways in insects. This review primarily discusses the roles of seminal fluid proteins (SFPs) and octopamine (OA) in various PMRs in insects. It explores the regulatory mechanisms and mediation conditions by which they trigger PMRs, along with the series of gene expression differences they induce. Insect PMRs involve a transition from protein signaling to neuronal signaling, ultimately manifested through neural regulation and gene expression. The intricate signaling network formed as a result significantly influences female behavior and organ function, contributing to both successful reproduction and the outcomes of sexual conflict.
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Affiliation(s)
| | | | - Dan-Ting Li
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China Jiliang University, Hangzhou 310018, China
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4
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Fricke C, Sanghvi K, Emery M, Lindenbaum I, Wigby S, Ramm SA, Sepil I. Timeless or tainted? The effects of male ageing on seminal fluid. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1066022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Reproductive ageing can occur due to the deterioration of both the soma and germline. In males, it has mostly been studied with respect to age-related changes in sperm. However, the somatic component of the ejaculate, seminal fluid, is also essential for maintaining reproductive function. Whilst we know that seminal fluid proteins (SFPs) are required for male reproductive success across diverse taxa, age-related changes in SFP quantity and composition are little understood. Additionally, only few studies have explored the reproductive ageing of the tissues that produce SFPs, and the resulting reproductive outcomes. Here we provide a systematic review of studies addressing how advancing male age affects the production and properties of seminal fluid, in particular SFPs and oxidative stress, highlighting many open questions and generating new hypotheses for further research. We additionally discuss how declines in function of different components of seminal fluid, such as SFPs and antioxidants, could contribute to age-related loss of reproductive ability. Overall, we find evidence that ageing results in increased oxidative stress in seminal fluid and a decrease in the abundance of various SFPs. These results suggest that seminal fluid contributes towards important age-related changes influencing male reproduction. Thus, it is essential to study this mostly ignored component of the ejaculate to understand male reproductive ageing, and its consequences for sexual selection and paternal age effects on offspring.
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5
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Xu X, Chen J, Du X, Yao L, Wang Y. CRISPR/Cas9 Mediated Disruption of Seminal Fluid Protein Sfp62 Induces Male Sterility in Bombyx mori. BIOLOGY 2022; 11:biology11040561. [PMID: 35453761 PMCID: PMC9024854 DOI: 10.3390/biology11040561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 11/25/2022]
Abstract
Simple Summary In gamogenetic animals, seminal fluid proteins are essential for male fertility. In this study, we investigated the function of the seminal fluid protein Sfp62 by using the CRISPR/Cas9 system in lepidopteran model insect Bombyx mori. Sfp62 mutation led to male sterility and can be inherited stably. The mutation did not affect growth and developmental nor female fertility. These data indicate that Sfp62 is an ideal target for sterile insect technology (SIT), in which genetically modified insects are released on a large scale to mate with wild-type insects in order to reduce or even eradicate the target pests. The determining factors for the effective implementation of SIT include the strong competitiveness of the modified individuals and multi-generational effects resulting from the mutation. Sfp62 meets these criteria and is therefore a promising target for biological pest control. Abstract Seminal fluid proteins provide factors necessary for development, storage, and activation of sperm. Altered expression of seminal fluid proteins can lead to defect in male infertility. We investigated the function of seminal fluid protein Sfp62 in the model lepidopteran insect Bombyx mori using CRISPR/Cas9 mediated mutagenesis. The knockout of BmSfp62 gene led to male sterility but has no effect on female fertility. The mutation did not affect growth and development of the silkworm of both sexes. Motility of sperm in male mutants was decreased and the mRNA expression levels of other genes encoding seminal fluid proteins were altered in BmSfp62 mutants compared to the wild-type controls. The male sterility caused by mutation of BmSfp62 was stably inherited. As the proteins encoded by Sfp62 genes are conserved among lepidopteran species, Sfp62 is a potential target for the biological management of lepidopteran pests.
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6
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Agudelo J, Alfonso-Parra C, Avila FW. Male Age Influences Re-mating Incidence and Sperm Use in Females of the Dengue Vector Aedes aegypti. Front Physiol 2021; 12:691221. [PMID: 34354600 PMCID: PMC8329734 DOI: 10.3389/fphys.2021.691221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/04/2021] [Indexed: 11/13/2022] Open
Abstract
Diseases transmitted by female Aedes aegypti mosquitoes are public health issues in countries in the tropics and sub-tropics. As in other insects, A. aegypti females undergo behavioral and physiological changes upon mating that principally act to facilitate the production of progeny. The primary effectors of A. aegypti female post-mating responses are male-derived seminal proteins that are transferred to females during mating. Increased male age reduces ejaculate function in numerous taxa and alters seminal protein composition in Drosophila melanogaster, but the impacts of male age on female A. aegypti post-mating responses are unknown. Here, we used "old" (21-22 days old) and "young" (4-5 days old) A. aegypti males to assess the influence of male age on oviposition, fertility, and re-mating incidence in their mates. We also examined how age influenced paternity share in females initially mated to young or old males that subsequently re-mated with a transgenic male that transferred RFP-labeled sperm and whose progeny inherited a larval-expressed GFP marker. We found that increased male age had no effect on female fecundity or fertility but significantly impacted their ability to prevent re-mating in their mates-more than half (54.5%) of the females mated to an old male re-mated, compared to 24% of females initially mated to a young male. Polyandrous A. aegypti females displayed first male precedence regardless of the age of their initial mate. However, young males were better able to compete with rival male sperm, siring significantly more progeny (77%) compared to old males (64%). Young males had significantly more sperm in their seminal vesicles than old males at the time of mating, although males of both age groups transferred similar numbers of sperm to their mates. Our results suggest that male senescence differentially impacts the induction of some post-mating changes in A. aegypti females. As the effect of age may be further exacerbated in the field, age-related declines in male ability to induce sexual refractoriness have implications for A. aegypti population control programs that release adults into the environment.
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Affiliation(s)
- Juliana Agudelo
- Max Planck Tandem Group in Mosquito Reproductive Biology, Universidad de Antioquia, Medellín, Colombia
| | - Catalina Alfonso-Parra
- Max Planck Tandem Group in Mosquito Reproductive Biology, Universidad de Antioquia, Medellín, Colombia.,Instituto Colombiano de Medicina Tropical, Universidad CES, Sabaneta, Colombia
| | - Frank W Avila
- Max Planck Tandem Group in Mosquito Reproductive Biology, Universidad de Antioquia, Medellín, Colombia
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7
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Bath E, Buzzoni D, Ralph T, Wigby S, Sepil I. Male condition influences female post mating aggression and feeding in
Drosophila. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13791] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eleanor Bath
- Department of Zoology University of Oxford Oxford UK
| | - Daisy Buzzoni
- Department of Zoology University of Oxford Oxford UK
- University of Victoria Victoria BC Canada
| | - Toby Ralph
- Department of Zoology University of Oxford Oxford UK
| | - Stuart Wigby
- Department of Zoology University of Oxford Oxford UK
- Department of Evolution, Ecology, and Behaviour Institute of Infection, Veterinary & Ecological Sciences University of Liverpool Liverpool UK
| | - Irem Sepil
- Department of Zoology University of Oxford Oxford UK
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8
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Ramm SA. Seminal fluid and accessory male investment in sperm competition. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200068. [PMID: 33070740 DOI: 10.1098/rstb.2020.0068] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sperm production and allocation strategies have been a central concern of sperm competition research for the past 50 years. But during the 'sexual cascade' there may be strong selection for alternative routes to maximizing male fitness. Especially with the evolution of internal fertilization, a common and by now well-studied example is the accessory ejaculate investment represented by seminal fluid, the complex mixture of proteins, peptides and other components transferred to females together with sperm. How seminal fluid investment should covary with sperm investment probably depends on the mechanism of seminal fluid action. If seminal fluid components boost male paternity success by directly enhancing sperm function or use, we might often expect a positive correlation between the two forms of male investment, whereas trade-offs seem more likely if seminal fluid acts independently of sperm. This is largely borne out by a broad taxonomic survey to establish the prevailing patterns of seminal fluid production and allocation during animal evolution, in light of which I discuss the gaps that remain in our understanding of this key ejaculate component and its relationship to sperm investment, before outlining promising approaches for examining seminal fluid-mediated sperm competitiveness in the post-genomic era. This article is part of the theme issue 'Fifty years of sperm competition'.
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Affiliation(s)
- Steven A Ramm
- Evolutionary Biology, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany
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9
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Sepil I, Hopkins BR, Dean R, Bath E, Friedman S, Swanson B, Ostridge HJ, Harper L, Buehner NA, Wolfner MF, Konietzny R, Thézénas ML, Sandham E, Charles PD, Fischer R, Steinhauer J, Kessler BM, Wigby S. Male reproductive aging arises via multifaceted mating-dependent sperm and seminal proteome declines, but is postponable in Drosophila. Proc Natl Acad Sci U S A 2020; 117:17094-17103. [PMID: 32611817 PMCID: PMC7382285 DOI: 10.1073/pnas.2009053117] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Declining ejaculate performance with male age is taxonomically widespread and has broad fitness consequences. Ejaculate success requires fully functional germline (sperm) and soma (seminal fluid) components. However, some aging theories predict that resources should be preferentially diverted to the germline at the expense of the soma, suggesting differential impacts of aging on sperm and seminal fluid and trade-offs between them or, more broadly, between reproduction and lifespan. While harmful effects of male age on sperm are well known, we do not know how much seminal fluid deteriorates in comparison. Moreover, given the predicted trade-offs, it remains unclear whether systemic lifespan-extending interventions could ameliorate the declining performance of the ejaculate as a whole. Here, we address these problems using Drosophila melanogaster. We demonstrate that seminal fluid deterioration contributes to male reproductive decline via mating-dependent mechanisms that include posttranslational modifications to seminal proteins and altered seminal proteome composition and transfer. Additionally, we find that sperm production declines chronologically with age, invariant to mating activity such that older multiply mated males become infertile principally via reduced sperm transfer and viability. Our data, therefore, support the idea that both germline and soma components of the ejaculate contribute to male reproductive aging but reveal a mismatch in their aging patterns. Our data do not generally support the idea that the germline is prioritized over soma, at least, within the ejaculate. Moreover, we find that lifespan-extending systemic down-regulation of insulin signaling results in improved late-life ejaculate performance, indicating simultaneous amelioration of both somatic and reproductive aging.
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Affiliation(s)
- Irem Sepil
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom;
| | - Ben R Hopkins
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom
- Department of Ecology and Evolution, University of California, Davis, CA 95616
| | - Rebecca Dean
- Department of Genetics, Evolution and Environment, University College London, WC1E 6BT London, United Kingdom
| | - Eleanor Bath
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom
| | | | - Ben Swanson
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom
| | - Harrison J Ostridge
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, WC1E 6BT London, United Kingdom
| | - Lucy Harper
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom
- School of Biology, University of St Andrews, KY16 9ST St Andrews, United Kingdom
| | - Norene A Buehner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Rebecca Konietzny
- Nuffield Department of Medicine, TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of Oxford, OX3 7FZ Oxford, United Kingdom
| | - Marie-Laëtitia Thézénas
- Nuffield Department of Medicine, TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of Oxford, OX3 7FZ Oxford, United Kingdom
| | - Elizabeth Sandham
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom
| | - Philip D Charles
- Nuffield Department of Medicine, TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of Oxford, OX3 7FZ Oxford, United Kingdom
| | - Roman Fischer
- Nuffield Department of Medicine, TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of Oxford, OX3 7FZ Oxford, United Kingdom
| | | | - Benedikt M Kessler
- Nuffield Department of Medicine, TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of Oxford, OX3 7FZ Oxford, United Kingdom
| | - Stuart Wigby
- Department of Zoology, University of Oxford, OX1 3SZ Oxford, United Kingdom
- Faculty Biology, Applied Zoology, Technische Universität Dresden, 01069 Dresden, Germany
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, L69 7ZB Liverpool, United Kingdom
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10
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Turnell BR, Reinhardt K. Metabolic Rate and Oxygen Radical Levels Increase But Radical Generation Rate Decreases with Male Age in Drosophila melanogaster Sperm. J Gerontol A Biol Sci Med Sci 2020; 75:2278-2285. [DOI: 10.1093/gerona/glaa078] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Indexed: 01/17/2023] Open
Abstract
Abstract
Oxidative damage increases with age in a variety of cell types, including sperm, which are particularly susceptible to attack by reactive oxygen species (ROS). While mitochondrial respiration is the main source of cellular ROS, the relationship between the rates of aerobic metabolism and ROS production, and how this relationship may be affected by age, both in sperm and in other cell types, is unclear. Here, we investigate in Drosophila melanogaster sperm, the effects of male age on (i) the level of hydrogen peroxide in the mitochondria, using a transgenic H2O2 reporter line; (ii) the in situ rate of non-H2O2 ROS production, using a novel biophysical method; and (iii) metabolic rate, using fluorescent lifetime imaging microscopy. Sperm from older males had higher mitochondrial ROS levels and a higher metabolic rate but produced ROS at a lower rate. In comparison, a somatic tissue, the gut epithelium, also showed an age-related increase in mitochondrial ROS levels but a decrease in metabolic rate. These results support the idea of a tissue-specific optimal rate of aerobic respiration balancing the production and removal of ROS, with aging causing a shift away from this optimum and leading to increased ROS accumulation. Our findings also support the view that pathways of germline and somatic aging can be uncoupled, which may have implications for male infertility treatments.
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Affiliation(s)
- Biz R Turnell
- Applied Zoology, Faculty Biology, Technische Universität Dresden, Germany
| | - Klaus Reinhardt
- Applied Zoology, Faculty Biology, Technische Universität Dresden, Germany
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11
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Gasparini C, Devigili A, Pilastro A. Sexual selection and ageing: interplay between pre- and post-copulatory traits senescence in the guppy. Proc Biol Sci 2020; 286:20182873. [PMID: 30963845 DOI: 10.1098/rspb.2018.2873] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Traits associated with mating and fertilization success are expected to senesce with age, but limited information is available on their relative rates of senescence. In polyandrous species, male reproductive fitness depends on both mating and fertilization success. Because successful mating is a prerequisite for post-copulatory sexual selection, ejaculate traits are expected to senesce faster than pre-copulatory traits, as pre-copulatory sexual selection is often deemed to be stronger than post-copulatory sexual selection. This pattern has generally been found in the few empirical studies conducted so far. We tested this prediction in the guppy ( Poecilia reticulata), a livebearing fish characterized by intense sperm competition, by comparing the expression of male sexual traits at two ages (four and nine months). Contrary to prediction, we found that post-copulatory traits senesced at a significantly slower rate than pre-copulatory traits. We also looked at whether early investment in those sexual traits affects longevity, and the interaction between sperm age (duration of sperm storage inside the male) and male age. Our results suggest that the relative senescence rate of pre- and post-copulatory sexual traits may vary among species with different mating systems and ecology.
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Affiliation(s)
- Clelia Gasparini
- 1 Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia , Crawley, Western Australia 6009 , Australia.,2 Department of Biology, University of Padova , 35131 Padova , Italy
| | - Alessandro Devigili
- 2 Department of Biology, University of Padova , 35131 Padova , Italy.,3 Department of Zoology, Stockholm University , Stockholm 106 91 , Sweden
| | - Andrea Pilastro
- 2 Department of Biology, University of Padova , 35131 Padova , Italy
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12
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Meuti ME, Short SM. Physiological and Environmental Factors Affecting the Composition of the Ejaculate in Mosquitoes and Other Insects. INSECTS 2019; 10:E74. [PMID: 30875967 PMCID: PMC6468485 DOI: 10.3390/insects10030074] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/05/2019] [Accepted: 03/08/2019] [Indexed: 01/02/2023]
Abstract
In addition to transferring sperm, male mosquitoes deliver several proteins, hormones and other factors to females in their seminal fluid that inhibit remating, alter host-seeking behaviors and stimulate oviposition. Recently, bioinformatics, transcriptomics and proteomics have been used to characterize the genes transcribed in male reproductive tissues and the individual proteins that are delivered to females. Thanks to these foundational studies, we now understand the complexity of the ejaculate in several mosquito species. Building on this work, researchers have begun to identify the functions of various proteins and hormones in the male ejaculate, and how they mediate their effects on female mosquitoes. Here, we present an overview of these studies, followed by a discussion of an under-studied aspect of male reproductive physiology: the effects of biotic and abiotic factors on the composition of the ejaculate. We argue that future research in this area would improve our understanding of male reproductive biology from a physiological and ecological perspective, and that researchers may be able to leverage this information to study key components of the ejaculate. Furthermore, this work has the potential to improve mosquito control by allowing us to account for relevant factors when implementing vector control strategies involving male reproductive biology.
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Affiliation(s)
- Megan E Meuti
- Department of Entomology, The Ohio State University, 2001 Fyffe Rd., Room 232 Howlett Hall, Columbus, OH 43210, USA.
| | - Sarah M Short
- Department of Entomology, The Ohio State University, 2001 Fyffe Rd., Room 232 Howlett Hall, Columbus, OH 43210, USA.
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13
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Sepil I, Hopkins BR, Dean R, Thézénas ML, Charles PD, Konietzny R, Fischer R, Kessler BM, Wigby S. Quantitative Proteomics Identification of Seminal Fluid Proteins in Male Drosophila melanogaster. Mol Cell Proteomics 2019; 18:S46-S58. [PMID: 30287546 PMCID: PMC6427238 DOI: 10.1074/mcp.ra118.000831] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/12/2018] [Indexed: 12/21/2022] Open
Abstract
Seminal fluid contains some of the fastest evolving proteins currently known. These seminal fluid proteins (Sfps) play crucial roles in reproduction, such as supporting sperm function, and particularly in insects, modifying female physiology and behavior. Identification of Sfps in small animals is challenging, and often relies on samples taken from the female reproductive tract after mating. A key pitfall of this method is that it might miss Sfps that are of low abundance because of dilution in the female-derived sample or rapid processing in females. Here we present a new and complementary method, which provides added sensitivity to Sfp identification. We applied label-free quantitative proteomics to Drosophila melanogaster, male reproductive tissue - where Sfps are unprocessed, and highly abundant - and quantified Sfps before and immediately after mating, to infer those transferred during copulation. We also analyzed female reproductive tracts immediately before and after copulation to confirm the presence and abundance of known and candidate Sfps, where possible. Results were cross-referenced with transcriptomic and sequence databases to improve confidence in Sfp detection. Our data were consistent with 125 previously reported Sfps. We found nine high-confidence novel candidate Sfps, which were both depleted in mated versus, unmated males and identified within the reproductive tract of mated but not virgin females. We also identified 42 more candidates that are likely Sfps based on their abundance, known expression and predicted characteristics, and revealed that four proteins previously identified as Sfps are at best minor contributors to the ejaculate. The estimated copy numbers for our candidate Sfps were lower than for previously identified Sfps, supporting the idea that our technique provides a deeper analysis of the Sfp proteome than previous studies. Our results demonstrate a novel, high-sensitivity approach to the analysis of seminal fluid proteomes, whose application will further our understanding of reproductive biology.
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Affiliation(s)
- Irem Sepil
- From the ‡Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK;.
| | - Ben R Hopkins
- From the ‡Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK
| | - Rebecca Dean
- Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Marie-Laëtitia Thézénas
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Philip D Charles
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rebecca Konietzny
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Roman Fischer
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Benedikt M Kessler
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Stuart Wigby
- From the ‡Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK
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14
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Churchill ER, Dytham C, Thom MDF. Differing effects of age and starvation on reproductive performance in Drosophila melanogaster. Sci Rep 2019; 9:2167. [PMID: 30770855 PMCID: PMC6377613 DOI: 10.1038/s41598-019-38843-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 01/10/2019] [Indexed: 02/02/2023] Open
Abstract
Successful reproduction requires the completion of many, often condition-dependent, stages, from mate searching and courtship through to sperm transfer, fertilisation and offspring production. Animals can plastically adjust their investment in each stage according to the physical and social environment, their own condition, their future reproductive potential, and the condition of their partner. Here we manipulate age and condition, through a nutritional challenge early or late in life, of both male and female Drosophila melanogaster and measure the effects on courtship, mating, and fitness when paired with a standardized (unmanipulated) partner. Older males were slower to start courting and mating, and courted at a slower rate, but males were indifferent to female age or condition despite older females laying and hatching fewer eggs. Female condition had a substantial effect on mating acceptance rate, which dropped dramatically after starvation, and particularly recent starvation experience. In contrast, male condition had little effect on any of the components of reproductive performance we measured. Intriguingly, we found no evidence for additive or multiplicative effects of ageing and starvation: the only significant interaction between these variables was on male latency to initiate courtship - older males were slower to start courting unless they had experienced starvation early in life. These results indicate that the immediate costs of mating differ between males and females, and that the sexes differ in their perception of the opportunity cost sustained by refusing a mating opportunity. Our results support the idea that ageing has more wide-ranging impact on reproductive behaviours than does nutritional challenge.
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Affiliation(s)
- Emily R Churchill
- Department of Biology, University of York, York, YO10 5DD, UK
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK
| | - Calvin Dytham
- Department of Biology, University of York, York, YO10 5DD, UK
| | - Michael D F Thom
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK.
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15
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Heinze J, Hanoeffner M, Delabie JHC, Schrempf A. Methuselah's daughters: Paternal age has little effect on offspring number and quality in Cardiocondyla ants. Ecol Evol 2018; 8:12066-12072. [PMID: 30598800 PMCID: PMC6303694 DOI: 10.1002/ece3.4666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/28/2018] [Accepted: 10/03/2018] [Indexed: 11/10/2022] Open
Abstract
Male age may directly or indirectly affect the fitness of their female mating partners and their joint progeny. While in some taxa of insects, old males make better mates and fathers, young males excel in others. Males of most social Hymenoptera are relatively short lived and because of testis degeneration have only a limited sperm supply. In contrast, the wingless fighter males of the ant Cardiocondyla obscurior live for several weeks and produce sperm throughout their lives. Wingless males engage in lethal combat with rival males and the winner of such fights can monopolize mating with all female sexuals that emerge in their nests over a prolonged timespan. Here, we investigate if male age has an influence on sperm quality, the queen's lifespan and productivity, and the size and weight of their offspring. Queens mated to one-week or six-week-old males did not differ in life expectancy and offspring production, but the daughters of young males were slightly heavier than those of old males. Our data suggest negligible reproductive senescence of C. obscurior males even at an age, which only few of them reach. This matches the reproductive strategy of Cardiocondyla ants, in which freshly emerging female sexuals rarely have the option to mate with males other than the one present in their natal nest.
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Affiliation(s)
- Jürgen Heinze
- LS Zoologie/EvolutionsbiologieUniversität RegensburgRegensburgGermany
| | | | - Jacques H. C. Delabie
- Myrmecological LaboratoryCocoa Research Center CEPLACIlhéusBahiaBrazil
- Santa Cruz State University‐DCAAIlhéusBahiaBrazil
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16
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Koppik M, Ruhmann H, Fricke C. The effect of mating history on male reproductive ageing in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2018; 111:16-24. [PMID: 30312587 DOI: 10.1016/j.jinsphys.2018.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/06/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
Mating bears costs, but how these costs affect the senescence of reproductive traits in males has received relatively little attention. Males of many species show reduced benefits from pre- and post-copulatory reproductive traits during ageing. Senescence of post-copulatory reproductive traits is often linked to a reduction in sperm quantity and quality, but can also be a consequence of changes in seminal fluid proteins that are transferred alongside sperm during mating. Here we investigated how mating history affects male reproductive ageing, especially at the post-copulatory level, using Drosophila melanogaster, a species in which links between seminal fluid proteins and male reproductive traits are well established. Besides a male cohort kept virgin until the start of the experiment we also included a cohort of males kept together with females allowing for ample mating opportunities. With these males we conducted a series of behavioral experiments covering several aspects of male reproductive success with males ranging in age from 4 days to 6 weeks after eclosion. Additionally, we investigated the storage capacity of male accessory glands (AG), the production site of the majority of seminal fluid proteins. We found male reproductive success to decline with increasing male age and, most importantly, males with prior matings showed a reduced performance in pre-copulatory success. However, our data suggest a constant short-term cost of mating rather than an accelerated senescence of pre-copulatory traits. In contrast, senescence of post-copulatory reproductive traits differed between mated and virgin males, hinting at mating costs in males altering the ageing process. We could not find any differences in the capacity of the AG to store seminal fluid proteins, however, our data suggest that old males transfer fewer seminal fluid proteins in a single mating. We conclude that a variety of traits is affected by male reproductive ageing in D. melanogaster with the cost of mating varying in its impact on senescence in these traits.
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Affiliation(s)
- Mareike Koppik
- Institute for Evolution and Biodiversity, University of Muenster, Huefferstr. 1, D-48149 Muenster, Germany.
| | - Hanna Ruhmann
- Institute for Evolution and Biodiversity, University of Muenster, Huefferstr. 1, D-48149 Muenster, Germany; Muenster Graduate School of Evolution, University of Muenster, Huefferstr. 1a, D-48149 Muenster, Germany.
| | - Claudia Fricke
- Institute for Evolution and Biodiversity, University of Muenster, Huefferstr. 1, D-48149 Muenster, Germany.
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17
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Wensing KU, Fricke C. Divergence in sex peptide-mediated female post-mating responses in Drosophila melanogaster. Proc Biol Sci 2018; 285:rspb.2018.1563. [PMID: 30209231 PMCID: PMC6158525 DOI: 10.1098/rspb.2018.1563] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/20/2018] [Indexed: 01/08/2023] Open
Abstract
Transfer and receipt of seminal fluid proteins crucially affect reproductive processes in animals. Evolution in these male ejaculatory proteins is explained with post-mating sexual selection, but we lack a good understanding of the evolution of female post-mating responses (PMRs) to these proteins. Some of these proteins are expected to mediate sexually antagonistic coevolution generating the expectation that females evolve resistance. One candidate in Drosophila melanogaster is the sex peptide (SP) which confers cost of mating in females. In this paper, we compared female SP-induced PMRs across three D. melanogaster wild-type populations after mating with SP-lacking versus control males including fitness measures. Surprisingly, we did not find any evidence for SP-mediated fitness costs in any of the populations. However, female lifetime reproductive success and lifespan were differently affected by SP receipt indicating that female PMRs diverged among populations. Injection of synthetic SP into virgin females further supported these findings and suggests that females from different populations require different amounts of SP to effectively initiate PMRs. Molecular analyses of the SP receptor suggest that genetic differences might explain the observed phenotypical divergence. We discuss the evolutionary processes that might have caused this divergence in female PMRs.
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Affiliation(s)
- Kristina U Wensing
- Institute for Evolution and Biodiversity, University of Muenster, Muenster 48149, Germany .,Muenster Graduate School of Evolution, University of Muenster, Muenster 48149, Germany
| | - Claudia Fricke
- Institute for Evolution and Biodiversity, University of Muenster, Muenster 48149, Germany
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