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Laugen AT, Hosken DJ, Reinhold K, Schwarzenbach GA, Hoeck PEA, Bussière LF, Blanckenhorn WU, Lüpold S. Sperm competition in yellow dung flies: No consistent effect of sperm size. J Evol Biol 2022; 35:1309-1318. [PMID: 35972882 DOI: 10.1111/jeb.14073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/09/2022] [Accepted: 07/12/2022] [Indexed: 01/07/2023]
Abstract
The male competition for fertilization that results from female multiple mating promotes the evolution of increased sperm numbers and can impact sperm morphology, with theory predicting that longer sperm can at times be advantageous during sperm competition. If so, males with longer sperm should sire more offspring than competitors with shorter sperm. Few studies have directly tested this prediction, and findings are inconsistent. Here we assessed whether longer sperm provide a competitive advantage in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae). Initially, we let brothers with different temperature-mediated mean sperm lengths compete - thus minimizing confounding effects of genetic background - and found no clear advantage of longer sperm. We then used flies from lines subjected to bidirectional selection on phenoloxidase activity that had shown correlated evolutionary responses in sperm and female spermathecal duct lengths. This experiment also yielded no main effect of sperm size on siring success. Instead, there was a trend for a shorter-sperm advantage, but only when competing in females with longer spermathecal ducts. Our data corroborated many previously reported findings (last-male precedence, effects of copula duration and body size), suggesting our failure to find sperm size effects is not inherently due to our experimental protocols. We conclude that longer sperm are not competitively superior in yellow dung flies under most circumstances, and that, consistent with previous work, in this species competitive fertilization success is primarily determined by the relative numbers of sperm competing.
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Affiliation(s)
- Ane T Laugen
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Centre for Coastal Research, Department of Natural Sciences, University of Agder, Kristiansand, Norway
| | - David J Hosken
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Centre for Ecology and Conservation, University of Exeter in Cornwall, Penryn, UK
| | - Klaus Reinhold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Evolutionsbiologie, Universität Bielefeld, Bielefeld, Germany
| | - Gioia A Schwarzenbach
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
| | - Paquita E A Hoeck
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
| | - Luc F Bussière
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland.,Biology and Environmental Sciences, University of Gothenburg and Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - Wolf U Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Zurich, Switzerland
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Walters RJ, Berger D, Blanckenhorn WU, Bussière LF, Rohner PT, Jochmann R, Thüler K, Schäfer MA. Growth rate mediates hidden developmental plasticity of female yellow dung fly reproductive morphology in response to environmental stressors. Evol Dev 2022; 24:3-15. [PMID: 35072984 PMCID: PMC9285807 DOI: 10.1111/ede.12396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/19/2021] [Accepted: 11/24/2021] [Indexed: 01/08/2023]
Abstract
Understanding how environmental variation influences even cryptic traits is important to clarify the roles of selection and developmental constraints in past evolutionary divergence and to predict future adaptation under environmental change. Female yellow dung flies (Scathophaga stercoraria) typically have three sperm storage compartments (3S), but occasionally four (4S). More spermathecae are thought to be a female adaptation facilitating sperm sorting after mating, but the phenotype is very rare in nature. We manipulated the flies' developmental environment by food restriction, pesticides, and hot temperatures to investigate the nature and extent of developmental plasticity of this trait, and whether spermatheca expression correlates with measures of performance and developmental stability, as would be expected if 4S expression is a developmental aberration. The spermathecal polymorphism of yellow dung fly females is heritable, but also highly developmentally plastic, varying strongly with rearing conditions. 4S expression is tightly linked to growth rate, and weakly positively correlated with fluctuating asymmetry of wings and legs, suggesting that the production of a fourth spermatheca could be a nonadaptive developmental aberration. However, spermathecal plasticity is opposite in the closely related and ecologically similar Scathophaga suilla, demonstrating that overexpression of spermathecae under developmental stress is not universal. At the same time, we found overall mortality costs as well as benefits of 4S pheno‐ and genotypes (also affecting male siblings), suggesting that a life history trade‐off may potentially moderate 4S expression. We conclude that the release of cryptic genetic variation in spermatheca number in the face of strong environmental variation may expose hidden traits (here reproductive morphology) to natural selection (here under climate warming or food augmentation). Once exposed, hidden traits can potentially undergo rapid genetic assimilation, even in cases when trait changes are first triggered by random errors that destabilize developmental processes. Female yellow dung flies naturally vary in number of sperm storage compartments (3S or 4S). This spermathecal polymorphism is strongly heritable but also developmentally plastic. 4S expression is linked to growth rate and weakly correlated with fluctuating asymmetry, so potentially a developmental aberration. There are mortality costs as well as benefits for 4S phenotypes, suggesting adaptive life‐history trade‐offs. Spermathecal plasticity differs in the closely related and ecologically similar Scathophaga suilla. Environmental changes can expose hidden traits with initially no function to natural selection.
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Affiliation(s)
- Richard J. Walters
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Centre for Environmental and Climate Research Lund University Lund Sweden
| | - David Berger
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Evolutionary Biology Centre University of Uppsala Uppsala Sweden
| | - Wolf U. Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Luc F. Bussière
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Biological and Environmental Sciences University of Stirling Stirling Scotland UK
- Biology and Environmental Sciences University of Gothenburg Gothenburg Sweden
| | - Patrick T. Rohner
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
- Department of Biology Indiana University Bloomington Indiana USA
| | - Ralf Jochmann
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Karin Thüler
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Martin A. Schäfer
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
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Simmons LW, Parker GA, Hosken DJ. Evolutionary insight from a humble fly: sperm competition and the yellow dungfly. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200062. [PMID: 33070730 DOI: 10.1098/rstb.2020.0062] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Studies of the yellow dungfly in the 1960s provided one of the first quantitative demonstrations of the costs and benefits associated with male and female reproductive behaviour. These studies advanced appreciation of sexual selection as a significant evolutionary mechanism and contributed to the 1970s paradigm shift toward individual selectionist thinking. Three behaviours in particular led to the realization that sexual selection can continue during and after mating: (i) female receptivity to remating, (ii) sperm displacement and (iii) post-copulatory mate guarding. These behaviours either generate, or are adaptations to sperm competition, cryptic female choice and sexual conflict. Here we review this body of work, and its contribution to the development of post-copulatory sexual selection theory. This article is part of the theme issue 'Fifty years of sperm competition'.
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Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, The University of Western Australia, Crawley 6009, Australia
| | - Geoff A Parker
- Department of Evolution, Ecology and Behaviour, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - David J Hosken
- Centre for Ecology and Conservation, University of Exeter, Cornwall, Penryn TR10 9FE, UK
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4
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Studying Genital Coevolution to Understand Intromittent Organ Morphology. Integr Comp Biol 2016; 56:669-81. [DOI: 10.1093/icb/icw018] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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Fowler-Finn KD, Rodríguez RL. The causes of variation in the presence of genetic covariance between sexual traits and preferences. Biol Rev Camb Philos Soc 2015; 91:498-510. [PMID: 25808899 DOI: 10.1111/brv.12182] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 02/12/2015] [Accepted: 03/03/2015] [Indexed: 02/02/2023]
Abstract
Mating traits and mate preferences often show patterns of tight correspondence across populations and species. These patterns of apparent coevolution may result from a genetic association between traits and preferences (i.e. trait-preference genetic covariance). We review the literature on trait-preference covariance to determine its prevalence and potential biological relevance. Of the 43 studies we identified, a surprising 63% detected covariance. We test multiple hypotheses for factors that may influence the likelihood of detecting this covariance. The main predictor was the presence of genetic variation in mate preferences, which is one of the three main conditions required for the establishment of covariance. In fact, 89% of the nine studies where heritability of preference was high detected covariance. Variables pertaining to the experimental methods and type of traits involved in different studies did not greatly influence the detection of trait-preference covariance. Trait-preference genetic covariance appears to be widespread and therefore represents an important and currently underappreciated factor in the coevolution of traits and preferences.
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Affiliation(s)
- Kasey D Fowler-Finn
- Department of Biology, Saint Louis University, Macelwane Hall, 3507 Laclede Ave., Saint Louis, MO 63103-2010, U.S.A
| | - Rafael L Rodríguez
- Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-Milwaukee, Lapham Hall, 3209 N. Maryland Ave., Milwaukee, WI 53201, U.S.A
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Gasparini C, Devigili A, Dosselli R, Pilastro A. Pattern of inbreeding depression, condition dependence, and additive genetic variance in Trinidadian guppy ejaculate traits. Ecol Evol 2013; 3:4940-53. [PMID: 24455127 PMCID: PMC3892359 DOI: 10.1002/ece3.870] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 10/08/2013] [Accepted: 10/10/2013] [Indexed: 11/13/2022] Open
Abstract
In polyandrous species, a male's reproductive success depends on his fertilization capability and traits enhancing competitive fertilization success will be under strong, directional selection. This leads to the prediction that these traits should show stronger condition dependence and larger genetic variance than other traits subject to weaker or stabilizing selection. While empirical evidence of condition dependence in postcopulatory traits is increasing, the comparison between sexually selected and ‘control’ traits is often based on untested assumption concerning the different strength of selection acting on these traits. Furthermore, information on selection in the past is essential, as both condition dependence and genetic variance of a trait are likely to be influenced by the pattern of selection acting historically on it. Using the guppy (Poecilia reticulata), a livebearing fish with high levels of multiple paternity, we performed three independent experiments on three ejaculate quality traits, sperm number, velocity, and size, which have been previously shown to be subject to strong, intermediate, and weak directional postcopulatory selection, respectively. First, we conducted an inbreeding experiment to determine the pattern of selection in the past. Second, we used a diet restriction experiment to estimate their level of condition dependence. Third, we used a half-sib/full-sib mating design to estimate the coefficients of additive genetic variance (CVA) underlying these traits. Additionally, using a simulated predator evasion test, we showed that both inbreeding and diet restriction significantly reduced condition. According to predictions, sperm number showed higher inbreeding depression, stronger condition dependence, and larger CVA than sperm velocity and sperm size. The lack of significant genetic correlation between sperm number and velocity suggests that the former may respond to selection independently one from other ejaculate quality traits. Finally, the association between sperm number and condition suggests that this trait may mediate the genetic benefits of polyandry which have been shown in this species.
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Affiliation(s)
| | | | - Ryan Dosselli
- Department of Biology, University of Padova Padova, Italy
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Puniamoorthy N, Blanckenhorn WU, Schäfer MA. Differential investment in pre- vs. post-copulatory sexual selection reinforces a cross-continental reversal of sexual size dimorphism inSepsis punctum(Diptera: Sepsidae). J Evol Biol 2012; 25:2253-63. [DOI: 10.1111/j.1420-9101.2012.02605.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/15/2012] [Accepted: 07/23/2012] [Indexed: 11/28/2022]
Affiliation(s)
| | - W. U. Blanckenhorn
- Institute of Evolutionary Biology and Environmental Studies; University of Zurich; Zurich; Switzerland
| | - M. A. Schäfer
- Institute of Evolutionary Biology and Environmental Studies; University of Zurich; Zurich; Switzerland
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Berger D, Bauerfeind SS, Blanckenhorn WU, Schäfer MA. HIGH TEMPERATURES REVEAL CRYPTIC GENETIC VARIATION IN A POLYMORPHIC FEMALE SPERM STORAGE ORGAN. Evolution 2011; 65:2830-42. [DOI: 10.1111/j.1558-5646.2011.01392.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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