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Dharmarathne C, McLean DJ, Herberstein ME, Schneider JM. Intraspecific body size variation and allometry of genitalia in the orb-web spider- Argiope lobata. PeerJ 2023; 11:e16413. [PMID: 38047024 PMCID: PMC10691382 DOI: 10.7717/peerj.16413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 10/17/2023] [Indexed: 12/05/2023] Open
Abstract
The current consensus is that sexual selection is responsible for the rapid and diverse evolution of genitalia, with several mutually exclusive mechanisms under debate, including non-antagonistic, antagonistic and stabilizing mechanisms. We used the orb-web spider, Argiope lobata (Araneidae), as a study model to quantify the allometric relationship between body size and genitalia, and to test for any impact of genital structures on male mating success or outcome in terms of copulation duration, leg loss or cannibalism. Our data do not support the 'one-size-fits-all' hypothesis that predicts a negative allometric slope between genitalia and body size. Importantly, we measured both male and female genitalia, and there was no sex specific pattern in allometric slopes. Unexpectedly, we found no predictor for reproductive success as indicated by copulation duration, cannibalism, and leg loss.
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Affiliation(s)
| | - Donald James McLean
- School of Natural Sciences, Macquarie University, North Ryde, New South Wales, Australia
| | - Marie E. Herberstein
- School of Natural Sciences, Macquarie University, North Ryde, New South Wales, Australia
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2
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Demont M, Ward PI, Blanckenhorn WU, Lüpold S, Martin OY, Bussière LF. How biases in sperm storage relate to sperm use during oviposition in female yellow dung flies. Behav Ecol 2021. [DOI: 10.1093/beheco/arab026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Abstract
Precise mechanisms underlying sperm storage and utilization are largely unknown, and data directly linking stored sperm to paternity remain scarce. We used competitive microsatellite PCR to study the effects of female morphology, copula duration and oviposition on the proportion of stored sperm provided by the second of two copulating males (S2) in Scathophaga stercoraria (Diptera: Scathophagidae), the classic model for sperm competition studies. We genotyped all offspring from potentially mixed-paternity clutches to establish the relationship between a second male’s stored sperm (S2) and paternity success (P2). We found consistent skew in sperm storage across the three female spermathecae, with relatively more second-male sperm stored in the singlet spermatheca than in the doublet spermathecae. S2 generally decreased with increasing spermathecal size, consistent with either heightened first-male storage in larger spermathecae, or less efficient sperm displacement in them. Additionally, copula duration and several two-way interactions influenced S2, highlighting the complexity of postcopulatory processes and sperm storage. Importantly, S2 and P2 were strongly correlated. Manipulation of the timing of oviposition strongly influenced observed sperm-storage patterns, with higher S2 when females laid no eggs before being sacrificed than when they oviposited between copulations, an observation consistent with adaptive plasticity in insemination. Our results identified multiple factors influencing sperm storage, nevertheless suggesting that the proportion of stored sperm is strongly linked to paternity (i.e., a fair raffle). Even more detailed data in this vein are needed to evaluate the general importance of sperm competition relative to cryptic female choice in postcopulatory sexual selection.
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Affiliation(s)
- Marco Demont
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
- Department of Biology and Institute of Integrative Biology, ETH Zurich, Universitätsstrasse 16, 8092 Zurich, Switzerland
| | - Paul I Ward
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
| | - Wolf U Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
| | - Oliver Y Martin
- Department of Biology and Institute of Integrative Biology, ETH Zurich, Universitätsstrasse 16, 8092 Zurich, Switzerland
| | - Luc F Bussière
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel Winterthurerstrasse 190, Zurich, Switzerland
- Biological and Environmental Sciences, University of Stirling, Stirling, Scotland, UK
- Biology and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
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3
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Bhaisare LY, Paraste S, Kaushik S, Chaudhary DD, Al-Misned F, Mahboob S, Al-Ghanim K, Ansari MJ. Reproductive success in Zygogramma bicolorata: A role of post-insemination association of male and female. Saudi J Biol Sci 2021; 28:1539-1543. [PMID: 33732037 PMCID: PMC7938115 DOI: 10.1016/j.sjbs.2020.12.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 11/28/2022] Open
Abstract
Reproductive success is attained by various mechanisms in insects. Prolonged post insemination association is one such mechanism to increase the reproductive success. The present study was conducted to assess the role of post insemination association of mating partners on reproductive performance in Chrysomelidae beetle, Zygogramma bicolorata Pallister. The matings were disrupted at different time intervals and fecundity and percent egg viability of the females were recorded. In addition, the mounting attempts, mating attempts, time to commencement of mating and latent period were also recorded. It was hypothesized that: (1) the mounting and mating attempts would not exist, (2) copulation duration, would not affect the reproductive performance, and (3) the beetle would not exhibit the mate guarding behaviour. Interestingly, results revealed that 6.00 ± 1.3 and 6.59 ± 0.93 mounting and mating attempts are needed to establish successful mating. The results revealed that males improved their percent egg viability with a mating duration ranging from nearly 30-50 min. While fecundity increased with a mating duration of above 30 min and up to a duration of 60 min. This result concluded that males of this beetle display post copulatory mate guarding behaviour after 60 min in which male rides on female's back with his aedeagus inserted in the female genital tract.
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Affiliation(s)
- Lankesh Yashwant Bhaisare
- Behavioural & Molecular Ecology & Biocontrol Research Laboratory, Department of Zoology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh 484887, India
| | - Sweta Paraste
- Behavioural & Molecular Ecology & Biocontrol Research Laboratory, Department of Zoology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh 484887, India
| | - Sandeep Kaushik
- Department of Environmental Science, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh 484887, India
| | - Desh Deepak Chaudhary
- Behavioural & Molecular Ecology & Biocontrol Research Laboratory, Department of Zoology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh 484887, India
| | - Fahad Al-Misned
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Shahid Mahboob
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Al-Ghanim
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Mohammad Javed Ansari
- Department of Botany, Hindu College Moradabad (Mahatma Jyotiba Phule Rohilkhand University Bareilly), India
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4
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House CM, Lewis Z, Sharma MD, Hodgson DJ, Hunt J, Wedell N, Hosken DJ. Sexual selection on the genital lobes of male Drosophila simulans. Evolution 2021; 75:501-514. [PMID: 33386741 DOI: 10.1111/evo.14158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/03/2020] [Accepted: 12/11/2020] [Indexed: 12/01/2022]
Abstract
Sexual selection is thought to be responsible for the rapid divergent evolution of male genitalia with several studies detecting multivariate sexual selection on genital form. However, in most cases, selection is only estimated during a single episode of selection, which provides an incomplete view of net selection on genital traits. Here, we estimate the strength and form of multivariate selection on the genitalia arch of Drosophila simulans when mating occurs in the absence of a competitor and during sperm competition, in both sperm defence and offense roles (i.e., when mating first and last). We found that the strength of sexual selection on the genital arch was strongest during noncompetitive mating and weakest during sperm offense. However, the direction of selection was similar across selection episodes with no evidence for antagonistic selection. Overall, selection was not particularly strong despite genitals clearly evolving rapidly in this species.
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Affiliation(s)
- Clarissa M House
- School of Science, Western Sydney University, Richmond, NSW, Australia
| | - Zenobia Lewis
- School of Life Sciences, University of Liverpool, Liverpool, UK
| | - Manmohan D Sharma
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - David J Hodgson
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - John Hunt
- School of Science, Western Sydney University, Richmond, NSW, Australia.,Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - Nina Wedell
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - David J Hosken
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
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5
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André GI, Firman RC, Simmons LW. Baculum shape and paternity success in house mice: evidence for genital coevolution. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200150. [PMID: 33070728 DOI: 10.1098/rstb.2020.0150] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sexual selection is believed to be responsible for the rapid divergence of male genitalia, which is a widely observed phenomenon across different taxa. Among mammals, the stimulatory role of male genitalia and female 'sensory perception' has been suggested to explain these evolutionary patterns. Recent research on house mice has shown that baculum (penis bone) shape can respond to experimentally imposed sexual selection. Here, we explore the adaptive value of baculum shape by performing two experiments that examine the effects of male and female genitalia on male reproductive success. Thus, we selected house mice (Mus musculus domesticus) from families characterized by extremes in baculum shape (relative width) and examined paternity success in both non-competitive (monogamous) and competitive (polyandrous) contexts. Our analyses revealed that the relative baculum shape of competing males influenced competitive paternity success, but that this effect was dependent on the breeding value for baculum shape of the family from which females were derived. Our data provide novel insight into the potential mechanisms underlying the evolution of the house mouse baculum and lend support to the stimulatory hypothesis for the coevolution of male and female genitalia. This article is part of the theme issue 'Fifty years of sperm competition'.
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Affiliation(s)
- Goncalo I André
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley, 6009 Western Australia, Australia
| | - Renée C Firman
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley, 6009 Western Australia, Australia
| | - Leigh W Simmons
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley, 6009 Western Australia, Australia
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6
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Sasson DA, Johnson TD, Scott ER, Fowler-Finn KD. Short-term water deprivation has widespread effects on mating behaviour in a harvestman. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.04.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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7
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Johansson F, Berger D, Höglund J, Meyer-Lucht Y, Rödin-Mörch P, Sniegula S, Watts PC. High variation in last male sperm precedence and genital morphology in the emerald damselfly, Lestes sponsa. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
In organisms in which individuals mate multiply, knowledge of the proportion of offspring sired by the last male to mate (P2) under field conditions is important for a thorough understanding of how sexual selection works in nature. In many insect groups, pronounced intraspecific variation in P2 is commonplace. Interestingly, however, in stark contrast to these observations, compilation of P2 data in dragonflies and damselflies (Odonata) indicates that a high P2, seldom below 0.95, is a feature of this taxon. Here we used double digest restriction-site associated DNA sequencing to generate a panel of single nucleotide polymorphisms (SNPs) with which we could determine paternity and estimate values of P2 in the offspring of 19 field-collected pairs of the emerald damselfly Lestes sponsa. We also estimated the relationship between P2 and male genital shape of 16 males using geometric morphometric analysis. P2 was variable (range = 0.0–1.0; mean = 0.5), and there was a marginally non-significant (P = 0.069) relationship between genital shape and P2, suggesting that males with a high P2 had an aedeagus with a broader tip. We suggest that the high P2-values reported in past studies in Odonata are partly due to the methods used to infer paternity. Use of SNPs to determine patterns of paternity and P2 in odonates is needed for a better appraisal of fitness in odonates, and would open many future avenues for use of odonates as models of sexual selection.
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Affiliation(s)
- Frank Johansson
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - David Berger
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Jacob Höglund
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Yvonne Meyer-Lucht
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Patrik Rödin-Mörch
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Szymon Sniegula
- Department of Ecosystem Conservation, Polish Academy of Sciences, Krakow, Poland
| | - Phillip C Watts
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
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8
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Wylde Z, Bonduriansky R. Condition dependence of phenotypic integration and the evolvability of genitalic traits in a neriid fly. Biol Lett 2020; 16:20200124. [PMID: 32453964 DOI: 10.1098/rsbl.2020.0124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The spectacular diversity of insect male genitalia, and their relative insensitivity to the environment, have long puzzled evolutionary biologists and taxonomists. We asked whether the unusual evolvability of male genitalia could be associated with low morphological integration of genitalic traits, by comparison with male somatic traits and female traits. We also asked whether this pattern was robust to variation in resource availability during development, which affects adult condition. To address these questions, we manipulated larval diet quality in a split-brood design and compared levels of integration of male and female genitalic and somatic traits in the neriid fly, Telostylinus angusticollis. We found that male genitalic traits were substantially less integrated than male somatic traits, and less integrated than female genitalic traits. Female genitalic traits were also less integrated than female somatic traits, but the difference was less pronounced than in males. However, integration of male genitalic traits was negatively condition-dependent, with high-condition males exhibiting lower trait integration than low-condition males. Finally, genitalic traits exhibited lower larval diet × family interactions than somatic traits. These results could help explain the unusually high evolvability of male genitalic traits in insects.
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Affiliation(s)
- Zachariah Wylde
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Russell Bonduriansky
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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9
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Abraham S, Moyano A, Murillo Dasso S, Van Nieuwenhove G, Ovruski S, Pérez-Staples D. Male accessory gland depletion in a tephritid fly affects female fecundity independently of sperm depletion. Behav Ecol Sociobiol 2020. [DOI: 10.1007/s00265-020-02835-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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10
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House C, Tunstall P, Rapkin J, Bale MJ, Gage M, Del Castillo E, Hunt J. Multivariate stabilizing sexual selection and the evolution of male and female genital morphology in the red flour beetle. Evolution 2020; 74:883-896. [PMID: 31889313 PMCID: PMC7317928 DOI: 10.1111/evo.13912] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/11/2019] [Accepted: 12/15/2019] [Indexed: 11/28/2022]
Abstract
Male genitals are highly divergent in animals with internal fertilization. Most studies attempting to explain this diversity have focused on testing the major hypotheses of genital evolution (the lock‐and‐key, pleiotropy, and sexual selection hypotheses), and quantifying the form of selection targeting male genitals has played an important role in this endeavor. However, we currently know far less about selection targeting female genitals or how male and female genitals interact during mating. Here, we use formal selection analysis to show that genital size and shape is subject to strong multivariate stabilizing sexual selection in both sexes of the red flour beetle, Tribolium castaneum. Moreover, we show significant sexual selection on the covariance between the sexes for specific aspects of genital shape suggesting that male and female genitalia also interact to determine the successful transfer of a spermatophore during mating. Our work therefore highlights the important role that both male and female genital morphologies play in determining mating success and that these effects can occur independently, as well as through their interaction. Moreover, it cautions against the overly simplistic view that the sexual selection targeting genital morphology will always be directional in form and restricted primarily to males.
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Affiliation(s)
- Clarissa House
- School of Science and Health and Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Philip Tunstall
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
| | - James Rapkin
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
| | - Mathilda J Bale
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
| | - Matthew Gage
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - Enrique Del Castillo
- Department of Industrial Engineering and Department of Statistics, Pennsylvania State University, State College, Pennsylvania, 16802
| | - John Hunt
- School of Science and Health and Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia.,Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
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11
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Casinos A, García-Martínez R, Borroto-Páez R. Cross-Sectional Geometry and Scaling in the Baculum of Cuban Hutias (Rodentia: Capromyidae). Anat Rec (Hoboken) 2019; 303:1346-1353. [PMID: 31569306 DOI: 10.1002/ar.24268] [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: 05/04/2018] [Revised: 02/28/2019] [Accepted: 06/05/2019] [Indexed: 11/08/2022]
Abstract
Bacula from 61 individual hutia (Rodentia) from five species were studied. The purpose was to investigate cross-sectional geometry as an indicator of mechanical behavior in order to answer questions around the origin and maintenance of the mammalian baculum. From images of the apical and basal cross sections, the following variables were calculated: perimeter, cross-sectional area, maximum second moment of area, and polar moment. An allometric analysis showed that these variables were related to body size. The orientation of the maximum second moment of area was analyzed by means of circular statistics. This orientation was transverse in both the apical and basal cross sections. Values for the second moment of area and polar moment, obtained from the predicted value of the allometric equations, showed that either the bending moment or the twisting moment of the baculum must be relatively low in hutias, compared with those of the radius in the same species. The results of the second moment of area predict that the main bending stress acting on the baculum is transverse. At the same time, shear stress would not be negligible. Anat Rec, 303:1346-1353, 2020. © 2019 American Association for Anatomy.
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Affiliation(s)
- Adrià Casinos
- Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Barcelona, Spain
| | - Rubén García-Martínez
- Centre de Restauració i Interpretació Paleontològica (CRIP), Els Hostalets de Pierola, Spain
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12
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Alpha shapes: determining 3D shape complexity across morphologically diverse structures. BMC Evol Biol 2018; 18:184. [PMID: 30518326 PMCID: PMC6282314 DOI: 10.1186/s12862-018-1305-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 11/23/2018] [Indexed: 11/15/2022] Open
Abstract
Background Following recent advances in bioimaging, high-resolution 3D models of biological structures are now generated rapidly and at low-cost. To use this data to address evolutionary and ecological questions, an array of tools has been developed to conduct shape analysis and quantify topographic complexity. Here we focus particularly on shape techniques applied to irregular-shaped objects lacking clear homologous landmarks, and propose a new ‘alpha-shapes’ method for quantifying 3D shape complexity. Methods We apply alpha-shapes to quantify shape complexity in the mammalian baculum as an example of a morphologically disparate structure. Micro- computed-tomography (μCT) scans of bacula were conducted. Bacula were binarised and converted into point clouds. Following application of a scaling factor to account for absolute size differences, a suite of alpha-shapes was fitted per specimen. An alpha shape is formed from a subcomplex of the Delaunay triangulation of a given set of points, and ranges in refinement from a very coarse mesh (approximating convex hulls) to a very fine fit. ‘Optimal’ alpha was defined as the refinement necessary in order for alpha-shape volume to equal CT voxel volume, and was taken as a metric of overall ‘complexity’. Results Our results show that alpha-shapes can be used to quantify interspecific variation in shape ‘complexity’ within biological structures of disparate geometry. The ‘stepped’ nature of alpha curves is informative with regards to the contribution of specific morphological features to overall ‘complexity’. Alpha-shapes agrees with other measures of complexity (dissection index, Dirichlet normal energy) in identifying ursid bacula as having low shape complexity. However, alpha-shapes estimates mustelid bacula as being most complex, contrasting with other shape metrics. 3D fractal dimension is identified as an inappropriate metric of complexity when applied to bacula. Conclusions Alpha-shapes is used to calculate ‘optimal’ alpha refinement as a proxy for shape ‘complexity’ without identifying landmarks. The implementation of alpha-shapes is straightforward, and is automated to process large datasets quickly. We interpret alpha-shapes as being particularly sensitive to concavities in surface topology, potentially distinguishing it from other shape complexity metrics. Beyond genital shape, the alpha-shapes technique holds considerable promise for new applications across evolutionary, ecological and palaeoecological disciplines.
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13
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14
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Orbach DN, Kelly DA, Solano M, Brennan PLR. Genital interactions during simulated copulation among marine mammals. Proc Biol Sci 2018; 284:rspb.2017.1265. [PMID: 29021172 DOI: 10.1098/rspb.2017.1265] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 09/04/2017] [Indexed: 11/12/2022] Open
Abstract
Genitalia are morphologically variable across many taxa and in physical contact during intromission, but little is known about how variation in form correlates with function during copulation. Marine mammals offer important insights into the evolutionary forces that act on genital morphology because they have diverse genitalia and are adapted to aquatic living and mating. Cetaceans have a fibroelastic penis and muscular vaginal folds, while pinnipeds have a baculum and lack vaginal folds. We examined copulatory fit in naturally deceased marine mammals to identify anatomical landmarks in contact during copulation and the potential depth of penile penetration into the vagina. Excised penises were artificially inflated to erection with pressurized saline and compared with silicone vaginal endocasts and within excised vaginas in simulated copulation using high-resolution, diffusible iodine-based, contrast-enhanced computed tomography. We found evidence suggestive of both congruent and antagonistic genital coevolution, depending on the species. We suggest that sexual selection influences morphological shape. This study improves our understanding of how mechanical interactions during copulation influence the shape of genitalia and affect fertility, and has broad applications to other taxa and species conservation.
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Affiliation(s)
- Dara N Orbach
- Department of Biology, Life Science Center, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, B3H 4R2, Canada .,Department of Biological Sciences, Mount Holyoke College, 50 College Street, South Hadley, MA 01075, USA
| | - Diane A Kelly
- Department of Psychological and Brain Sciences, University of Massachusetts, 135 Hicks Way, Amherst, MA 01003, USA
| | - Mauricio Solano
- Clinical Sciences Department, Tufts University Cummings School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA
| | - Patricia L R Brennan
- Department of Biological Sciences, Mount Holyoke College, 50 College Street, South Hadley, MA 01075, USA
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15
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Horváth B, Kalinka AT. The genetics of egg retention and fertilization success in Drosophila: One step closer to understanding the transition from facultative to obligate viviparity. Evolution 2018; 72:318-336. [PMID: 29265369 DOI: 10.1111/evo.13411] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 10/16/2017] [Accepted: 11/14/2017] [Indexed: 12/17/2022]
Abstract
Oviparous, facultative egg retention enables Drosophila females to withhold fertilized eggs in their reproductive tracts until circumstances favor oviposition. The propensity to retain fertilized eggs varies greatly between species, and is correlated with other reproductive traits, such as egg size and ovariole number. While previous studies have described the phenomenon, no study to date has characterized within-species variation or the genetic basis of the trait. Here, we develop a novel microscope-based method for measuring egg retention in Drosophila females and determine the range of phenotypic variation in mated female egg retention in a subset of 91 Drosophila Genetic Reference Panel (DGRP) lines. We inferred the genetic basis of egg retention using a genome-wide association study (GWAS). Further, the scoring of more than 95,000 stained, staged eggs enabled estimates of fertilization success for each line. We found evidence that ovary- and spermathecae-related genes as well as genes affecting olfactory behavior, male mating behavior, male-female attraction and sperm motility may play a crucial role in post-mating physiology. Based on our findings we also propose potential evolutionary routes toward obligate viviparity. In particular, we propose that the loss of fecundity incurred by viviparity could be offset by benefits arising from enhanced mate discrimination, resource specialization, or modified egg morphology.
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Affiliation(s)
- Barbara Horváth
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Veterinärplatz 1, Vienna A-1210, Austria.,Vienna Graduate School of Population Genetics, Veterinärmedizinische Universität Wien, Veterinärplatz 1, Vienna A-1210, Austria.,Current Address: Barbara Ellis, Institutionen för ekologi och genetik, Evolutionsbiologiskt Centrum (EBC), Norbyvägen 18D, 752 36 Uppsala, Sweden
| | - Alex T Kalinka
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Veterinärplatz 1, Vienna A-1210, Austria
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16
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Jauset AM, Edo-Tena E, Parés-Casanova PM, Castañé C, Agustí N, Alomar O. Elliptic Fourier Analysis in the Study of the Male Genitalia to Discriminate Three Macrolophus Species (Hemiptera: Miridae). INSECTS 2017; 8:insects8040120. [PMID: 29104240 PMCID: PMC5746803 DOI: 10.3390/insects8040120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 11/16/2022]
Abstract
Within the genus Macrolophus (Heteroptera: Miridae), the species M. costalis (Fieber), M. melanotoma (Costa) and M. pygmaeus (Rambur) are present in the Mediterranean region on a wide variety of plant species. While M. costalis can easily be separated from the other two by the black tip at the scutellum, M. pygmaeus and M. melanotoma are cryptic species, extremely similar to one another in external traits, which has resulted in misidentifications. M. pygmaeus is an efficient biological control agent, both in greenhouse and field crops. The misidentification of these cryptic species could limit the effectiveness of biological control programs. Although the morphology of the left paramere of the male genitalia has been used as a character for identification of these two cryptic species, there is controversy surrounding the reliability of this character as a taxonomic tool for these species. Using geometric morphometric techniques, which are a powerful approach in detecting slight shape variations, the left parameres from these three Macrolophus species were compared. The paramere of M. costalis was larger and had a different shape to that of M. melanotoma and M. pygmaeus; however, no differences in size or shape were found between the left paramere of M. melanotoma and that of M. pygmaeus. Therefore, our results confirm that this character is too similar and it cannot be used to discriminate between these two cryptic species.
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Affiliation(s)
- A M Jauset
- Department of Crop and Forest Sciences, University of Lleida, Alcalde Rovira Roure, 177, 25198 Lleida, Spain.
| | - E Edo-Tena
- Department of Crop and Forest Sciences, University of Lleida, Alcalde Rovira Roure, 177, 25198 Lleida, Spain.
| | - P M Parés-Casanova
- Department of Animal Production, University of Lleida, Alcalde Rovira Roure, 177, 25198 Lleida, Spain.
| | - C Castañé
- IRTA, Ctra. Cabrils Km 2, 08348 Cabrils (Barcelona), Spain.
| | - N Agustí
- IRTA, Ctra. Cabrils Km 2, 08348 Cabrils (Barcelona), Spain.
| | - O Alomar
- IRTA, Ctra. Cabrils Km 2, 08348 Cabrils (Barcelona), Spain.
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17
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Female remating decisions and a shorter inter-mating interval diminish last-male sperm precedence. Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2350-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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18
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Schultz NG, Lough-Stevens M, Abreu E, Orr T, Dean MD. The Baculum was Gained and Lost Multiple Times during Mammalian Evolution. Integr Comp Biol 2016; 56:644-56. [PMID: 27252214 PMCID: PMC6080509 DOI: 10.1093/icb/icw034] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The rapid evolution of male genitalia is a nearly ubiquitous pattern across sexually reproducing organisms, likely driven by the evolutionary pressures of male-male competition, male-female interactions, and perhaps pleiotropic effects of selection. The penis of many mammalian species contains a baculum, a bone that displays astonishing morphological diversity. The evolution of baculum size and shape does not consistently correlate with any aspects of mating system, hindering our understanding of the evolutionary processes affecting it. One potential explanation for the lack of consistent comparative results is that the baculum is not actually a homologous structure. If the baculum of different groups evolved independently, then the assumption of homology inherent in comparative studies is violated. Here, we specifically test this hypothesis by modeling the presence/absence of bacula of 954 mammalian species across a well-established phylogeny and show that the baculum evolved a minimum of nine times, and was lost a minimum of ten times. Three different forms of bootstrapping show our results are robust to species sampling. Furthermore, groups with a baculum show evidence of higher rates of diversification. Our study offers an explanation for the inconsistent results in the literature, and provides insight into the evolution of this remarkable structure.
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Affiliation(s)
- Nicholas G Schultz
- *Molecular and Computational Biology, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA
| | - Michael Lough-Stevens
- *Molecular and Computational Biology, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA
| | - Eric Abreu
- West Adams Preparatory High School, 1500 W Washington Blvd, Los Angeles, CA 90007, USA
| | - Teri Orr
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112-0840, USA
| | - Matthew D Dean
- *Molecular and Computational Biology, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA
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19
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House CM, Sharma MD, Okada K, Hosken DJ. Pre and Post-copulatory Selection Favor Similar Genital Phenotypes in the Male Broad Horned Beetle. Integr Comp Biol 2016; 56:682-93. [PMID: 27371390 PMCID: PMC5035384 DOI: 10.1093/icb/icw079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sexual selection can operate before and after copulation and the same or different trait(s) can be targeted during these episodes of selection. The direction and form of sexual selection imposed on characters prior to mating has been relatively well described, but the same is not true after copulation. In general, when male–male competition and female choice favor the same traits then there is the expectation of reinforcing selection on male sexual traits that improve competitiveness before and after copulation. However, when male–male competition overrides pre-copulatory choice then the opposite could be true. With respect to studies of selection on genitalia there is good evidence that male genital morphology influences mating and fertilization success. However, whether genital morphology affects reproductive success in more than one context (i.e., mating versus fertilization success) is largely unknown. Here we use multivariate analysis to estimate linear and nonlinear selection on male body size and genital morphology in the flour beetle Gnatocerus cornutus, simulated in a non-competitive (i.e., monogamous) setting. This analysis estimates the form of selection on multiple traits and typically, linear (directional) selection is easiest to detect, while nonlinear selection is more complex and can be stabilizing, disruptive, or correlational. We find that mating generates stabilizing selection on male body size and genitalia, and fertilization causes a blend of directional and stabilizing selection. Differences in the form of selection across these bouts of selection result from a significant alteration of nonlinear selection on body size and a marginally significant difference in nonlinear selection on a component of genital shape. This suggests that both bouts of selection favor similar genital phenotypes, whereas the strong stabilizing selection imposed on male body size during mate acquisition is weak during fertilization.
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Affiliation(s)
- Clarissa M House
- *Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, TR10 9EZ, UK
| | - M D Sharma
- *Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, TR10 9EZ, UK
| | - Kensuke Okada
- Laboratory of Evolutionary Ecology, Graduate School of Environmental Science, Okayama University, Tsushima-naka 1-1-1, Okayama, Japan
| | - David J Hosken
- *Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, TR10 9EZ, UK
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20
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Filippov AE, Matsumura Y, Kovalev AE, Gorb SN. Stiffness gradient of the beetle penis facilitates propulsion in the spiraled female spermathecal duct. Sci Rep 2016; 6:27608. [PMID: 27334674 PMCID: PMC4918010 DOI: 10.1038/srep27608] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/23/2016] [Indexed: 11/09/2022] Open
Abstract
It is well known that sexual selection is the main driving force of substantial diversity of genitalia found in animals. However, how it facilitates the diversity is still largely unknown, because genital morpho/physical features and motions/functional morphology of the structures in sexual intercourse are not linked for the vast majority of organisms. Here we showed the presence of material gradient and numerically studied an effect of stiffness gradient of the beetle penis during its propulsion through the female duct. We found that stiffness gradient on the penis essentially affects its propulsion. Microscopic investigation suggests the possibility that the tip of the hyper-elongated penis is softer than the rest of it, and our numerical model confirms that this type of distribution of stiffness gradient aids in faster propulsion than other types. This result indicates that previously ignored physical properties of genital materials are of crucial importance in evolutionary studies of genitalia.
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Affiliation(s)
- Alexander E Filippov
- Department Functional Morphology and Biomechanics, Zoological Institute of the Kiel University, Am Botanischen Garten 9, D-24118 Kiel, Germany.,Donetsk Institute for Physics and Engineering, National Academy of Science, 340114, Donetsk, Ukraine
| | - Yoko Matsumura
- Department Functional Morphology and Biomechanics, Zoological Institute of the Kiel University, Am Botanischen Garten 9, D-24118 Kiel, Germany.,Department of Biology, Keio University, 4-1-1 Hiyoshi, Yokohama 223-8521, Japan
| | - Alexander E Kovalev
- Department Functional Morphology and Biomechanics, Zoological Institute of the Kiel University, Am Botanischen Garten 9, D-24118 Kiel, Germany
| | - Stanislav N Gorb
- Department Functional Morphology and Biomechanics, Zoological Institute of the Kiel University, Am Botanischen Garten 9, D-24118 Kiel, Germany
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21
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Booksmythe I, Head ML, Keogh JS, Jennions MD. Fitness consequences of artificial selection on relative male genital size. Nat Commun 2016; 7:11597. [PMID: 27188478 PMCID: PMC4873965 DOI: 10.1038/ncomms11597] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/12/2016] [Indexed: 11/12/2022] Open
Abstract
Male genitalia often show remarkable differences among related species in size, shape and complexity. Across poeciliid fishes, the elongated fin (gonopodium) that males use to inseminate females ranges from 18 to 53% of body length. Relative genital size therefore varies greatly among species. In contrast, there is often tight within-species allometric scaling, which suggests strong selection against genital-body size combinations that deviate from a species' natural line of allometry. We tested this constraint by artificially selecting on the allometric intercept, creating lines of males with relatively longer or shorter gonopodia than occur naturally for a given body size in mosquitofish, Gambusia holbrooki. We show that relative genital length is heritable and diverged 7.6-8.9% between our up-selected and down-selected lines, with correlated changes in body shape. However, deviation from the natural line of allometry does not affect male success in assays of attractiveness, swimming performance and, crucially, reproductive success (paternity).
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Affiliation(s)
- Isobel Booksmythe
- Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Building 116, Daley Road, Acton, Canberra, Australian Capital Territory 2601, Australia
- Centre of Excellence in Biological Interactions Research, Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - Megan L Head
- Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Building 116, Daley Road, Acton, Canberra, Australian Capital Territory 2601, Australia
| | - J Scott Keogh
- Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Building 116, Daley Road, Acton, Canberra, Australian Capital Territory 2601, Australia
| | - Michael D Jennions
- Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Building 116, Daley Road, Acton, Canberra, Australian Capital Territory 2601, Australia
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22
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Schultz NG, Ingels J, Hillhouse A, Wardwell K, Chang PL, Cheverud JM, Lutz C, Lu L, Williams RW, Dean MD. The Genetic Basis of Baculum Size and Shape Variation in Mice. G3 (BETHESDA, MD.) 2016; 6:1141-51. [PMID: 26935419 PMCID: PMC4856068 DOI: 10.1534/g3.116.027888] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/05/2016] [Indexed: 01/01/2023]
Abstract
The rapid divergence of male genitalia is a preeminent evolutionary pattern. This rapid divergence is especially striking in the baculum, a bone that occurs in the penis of many mammalian species. Closely related species often display diverse baculum morphology where no other morphological differences can be discerned. While this fundamental pattern of evolution has been appreciated at the level of gross morphology, nearly nothing is known about the genetic basis of size and shape divergence. Quantifying the genetic basis of baculum size and shape variation has been difficult because these structures generally lack obvious landmarks, so comparing them in three dimensions is not straightforward. Here, we develop a novel morphometric approach to quantify size and shape variation from three-dimensional micro-CT scans taken from 369 bacula, representing 75 distinct strains of the BXD family of mice. We identify two quantitative trait loci (QTL) that explain ∼50% of the variance in baculum size, and a third QTL that explains more than 20% of the variance in shape. Together, our study demonstrates that baculum morphology may diverge relatively easily, with mutations at a few loci of large effect that independently modulate size and shape. Based on a combination of bioinformatic investigations and new data on RNA expression, we prioritized these QTL to 16 candidate genes, which have hypothesized roles in bone morphogenesis and may enable future genetic manipulation of baculum morphology.
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Affiliation(s)
- Nicholas G Schultz
- Molecular and Computational Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
| | - Jesse Ingels
- University of Tennessee, Health Science Center, Memphis, Tennessee 38163
| | - Andrew Hillhouse
- Texas A & M, Veterinary Medicine and Biomedical Sciences, College Station, Texas 77845
| | | | - Peter L Chang
- Molecular and Computational Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
| | - James M Cheverud
- Loyola University, Department of Biology, Chicago, Illinois 60626
| | | | - Lu Lu
- University of Tennessee, Health Science Center, Memphis, Tennessee 38163
| | - Robert W Williams
- University of Tennessee, Health Science Center, Memphis, Tennessee 38163
| | - Matthew D Dean
- Molecular and Computational Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089
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23
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Assis BA, Foellmer MW. One size fits all? Determinants of sperm transfer in a highly dimorphic orb-web spider. J Evol Biol 2016; 29:1106-20. [DOI: 10.1111/jeb.12848] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/02/2016] [Indexed: 11/28/2022]
Affiliation(s)
- B. A. Assis
- Department of Biology; Adelphi University; 1 South Ave. Garden City NY 11530 USA
| | - M. W. Foellmer
- Department of Biology; Adelphi University; 1 South Ave. Garden City NY 11530 USA
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24
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Friesen CR, Uhrig EJ, Mason RT, Brennan PLR. Female behaviour and the interaction of male and female genital traits mediate sperm transfer during mating. J Evol Biol 2016; 29:952-64. [PMID: 26809830 DOI: 10.1111/jeb.12836] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/18/2016] [Accepted: 01/19/2016] [Indexed: 02/04/2023]
Abstract
Natural selection and post-copulatory sexual selection, including sexual conflict, contribute to genital diversification. Fundamental first steps in understanding how these processes shape the evolution of specific genital traits are to determine their function experimentally and to understand the interactions between female and male genitalia during copulation. Our experimental manipulations of male and female genitalia in red-sided garter snakes (Thamnophis sirtalis parietalis) reveal that copulation duration and copulatory plug deposition, as well as total and oviductal/vaginal sperm counts, are influenced by the interaction between male and female genital traits and female behaviour during copulation. By mating females with anesthetized cloacae to males with spine-ablated hemipenes using a fully factorial design, we identified significant female-male copulatory trait interactions and found that females prevent sperm from entering their oviducts by contracting their vaginal pouch. Furthermore, these muscular contractions limit copulatory plug size, whereas the basal spine of the male hemipene aids in sperm and plug transfer. Our results are consistent with a role of sexual conflict in mating interactions and highlight the evolutionary importance of female resistance to reproductive outcomes.
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Affiliation(s)
- C R Friesen
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA.,School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, USA
| | - E J Uhrig
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - R T Mason
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - P L R Brennan
- Department of Biological Sciences, 104 Clapp Laboratory, Mount Holyoke College, South Hadley, MA, USA
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25
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Travers LM, Simmons LW, Garcia‐Gonzalez F. Additive genetic variance in polyandry enables its evolution, but polyandry is unlikely to evolve through sexy or good sperm processes. J Evol Biol 2016; 29:916-28. [DOI: 10.1111/jeb.12834] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 01/15/2016] [Indexed: 02/03/2023]
Affiliation(s)
- L. M. Travers
- Centre for Evolutionary Biology School of Animal Biology (M092) The University of Western Australia Crawley WA Australia
| | - L. W. Simmons
- Centre for Evolutionary Biology School of Animal Biology (M092) The University of Western Australia Crawley WA Australia
| | - F. Garcia‐Gonzalez
- Centre for Evolutionary Biology School of Animal Biology (M092) The University of Western Australia Crawley WA Australia
- Doñana Biological Station Spanish Research Council CSIC Sevilla Spain
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26
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Devost E, Turgeon J. The combined effects of pre- and post-copulatory processes are masking sexual conflict over mating rate in Gerris buenoi. J Evol Biol 2015; 29:167-77. [DOI: 10.1111/jeb.12772] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/07/2015] [Accepted: 10/09/2015] [Indexed: 12/01/2022]
Affiliation(s)
- E. Devost
- Département de biologie; Université Laval; Québec QC Canada
| | - J. Turgeon
- Département de biologie; Université Laval; Québec QC Canada
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27
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Takahara B, Takahashi KH. Genome-Wide Association Study on Male Genital Shape and Size in Drosophila melanogaster. PLoS One 2015; 10:e0132846. [PMID: 26182199 PMCID: PMC4504508 DOI: 10.1371/journal.pone.0132846] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 06/19/2015] [Indexed: 11/21/2022] Open
Abstract
Male genital morphology of animals with internal fertilization and promiscuous mating systems have been one of the most diverse and rapidly evolving morphological traits. The male genital morphology in general is known to have low phenotypic and genetic variations, but the genetic basis of the male genital variation remains unclear. Drosophila melanogaster and its closely related species are morphologically very similar, but the shapes of the posterior lobe, a cuticular projection on the male genital arch are distinct from each other, representing a model system for studying the genetic basis of male genital morphology. In this study, we used highly inbred whole genome sequenced strains of D. melanogaster to perform genome wide association analysis on posterior lobe morphology. We quantified the outline shape of posterior lobes with Fourier coefficients obtained from elliptic Fourier analysis and performed principal component analysis, and posterior lobe size. The first and second principal components (PC1 and PC2) explained approximately 88% of the total variation of the posterior lobe shape. We then examined the association between the principal component scores and posterior lobe size and 1902142 single nucleotide polymorphisms (SNPs). As a result, we obtained 15, 14 and 15 SNPs for PC1, PC2 and posterior lobe size with P-values smaller than 10(-5). Based on the location of the SNPs, 13, 13 and six protein coding genes were identified as potential candidates for PC1, PC2 and posterior lobe size, respectively. In addition to the previous findings showing that the intraspecific posterior shape variation are regulated by multiple QTL with strong effects, the present study suggests that the intraspecific variation may be under polygenic regulation with a number of loci with small effects. Further studies are required for investigating whether these candidate genes are responsible for the intraspecific posterior lobe shape variation.
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Affiliation(s)
- Baku Takahara
- Faculty of Agriculture, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama, 700–8530, Japan
| | - Kazuo H. Takahashi
- Graduate School of Environmental Science, Okayama University, Tsushima-naka 1-1-1, Kita-ku, Okayama, 700–8530, Japan
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28
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Heinen-Kay JL, Noel HG, Layman CA, Langerhans RB. Human-caused habitat fragmentation can drive rapid divergence of male genitalia. Evol Appl 2014; 7:1252-67. [PMID: 25558285 PMCID: PMC4275096 DOI: 10.1111/eva.12223] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/24/2014] [Indexed: 11/29/2022] Open
Abstract
The aim of this study rests on three premises: (i) humans are altering ecosystems worldwide, (ii) environmental variation often influences the strength and nature of sexual selection, and (iii) sexual selection is largely responsible for rapid and divergent evolution of male genitalia. While each of these assertions has strong empirical support, no study has yet investigated their logical conclusion that human impacts on the environment might commonly drive rapid diversification of male genital morphology. We tested whether anthropogenic habitat fragmentation has resulted in rapid changes in the size, allometry, shape, and meristics of male genitalia in three native species of livebearing fishes (genus: Gambusia) inhabiting tidal creeks across six Bahamian islands. We found that genital shape and allometry consistently and repeatedly diverged in fragmented systems across all species and islands. Using a model selection framework, we identified three ecological consequences of fragmentation that apparently underlie observed morphological patterns: decreased predatory fish density, increased conspecific density, and reduced salinity. Our results demonstrate that human modifications to the environment can drive rapid and predictable divergence in male genitalia. Given the ubiquity of anthropogenic impacts on the environment, future research should evaluate the generality of our findings and potential consequences for reproductive isolation.
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Affiliation(s)
- Justa L Heinen-Kay
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
| | - Holly G Noel
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
| | - Craig A Layman
- Department of Applied Ecology, North Carolina State University Raleigh, NC, USA
| | - R Brian Langerhans
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
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29
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Heinen-Kay JL, Langerhans RB. Predation-associated divergence of male genital morphology in a livebearing fish. J Evol Biol 2013; 26:2135-45. [DOI: 10.1111/jeb.12229] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/19/2013] [Accepted: 07/20/2013] [Indexed: 11/28/2022]
Affiliation(s)
- J. L. Heinen-Kay
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology; North Carolina State University; Raleigh NC USA
| | - R. B. Langerhans
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology; North Carolina State University; Raleigh NC USA
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30
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Barbosa F. Males responding to sperm competition cues have higher fertilization success in a soldier fly. Behav Ecol 2012. [DOI: 10.1093/beheco/ars035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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31
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Multiple Quantitative Trait Loci Influence the Shape of a Male-Specific Genital Structure in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2011; 1:343-51. [PMID: 22384345 PMCID: PMC3276151 DOI: 10.1534/g3.111.000661] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 08/12/2011] [Indexed: 11/18/2022]
Abstract
The observation that male genitalia diverge more rapidly than other morphological traits during evolution is taxonomically widespread and likely due to some form of sexual selection. One way to elucidate the evolutionary forces acting on these traits is to detail the genetic architecture of variation both within and between species, a program of research that is considerably more tractable in a model system. Drosophila melanogaster and its sibling species, D. simulans, D. mauritiana, and D. sechellia, are morphologically distinguishable only by the shape of the posterior lobe, a male-specific elaboration of the genital arch. We extend earlier studies identifying quantitative trait loci (QTL) responsible for lobe divergence across species and report the first genetic dissection of lobe shape variation within a species. Using an advanced intercross mapping design, we identify three autosomal QTL contributing to the difference in lobe shape between a pair of D. melanogaster inbred lines. The QTL each contribute 4.6–10.7% to shape variation, and two show a significant epistatic interaction. Interestingly, these intraspecific QTL map to the same locations as interspecific lobe QTL, implying some shared genetic control of the trait within and between species. As a first step toward a mechanistic understanding of natural lobe shape variation, we find an association between our QTL data and a set of genes that show sex-biased expression in the developing genital imaginal disc (the precursor of the adult genitalia). These genes are good candidates to harbor naturally segregating polymorphisms contributing to posterior lobe shape.
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32
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Gasparini C, Pilastro A, Evans JP. Male genital morphology and its influence on female mating preferences and paternity success in guppies. PLoS One 2011; 6:e22329. [PMID: 21799825 PMCID: PMC3142123 DOI: 10.1371/journal.pone.0022329] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 06/23/2011] [Indexed: 11/18/2022] Open
Abstract
In internally fertilizing species male genitalia often show a higher degree of elaboration than required for simply transferring sperm to females. Among the hypotheses proposed to explain such diversity, sexual selection has received the most empirical support, with studies revealing that genital morphology can be targeted by both pre-and postcopulatory sexual selection. Until now, most studies have focused on these two episodes of selection independently. Here, we take an alternative approach by considering both components simultaneously in the livebearing fish, Poecilia reticulata. We allowed females to mate successively (and cooperatively) with two males and determined whether male genital length influenced the female's propensity to mate with a male (precopulatory selection, via female choice) and whether male genital size and shape predicted the relative paternity share of subsequent broods (postcopulatory selection, via sperm competition/cryptic female choice). We found no evidence that either episode of sexual selection targets male genital size or shape. These findings, in conjunction with our recent work exposing a role of genital morphology in mediating unsolicited (forced) matings in guppies, further supports our prior speculation that sexual conflict may be an important broker of genital evolution in this species.
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33
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Simmons LW, Garcia-Gonzalez F. Experimental coevolution of male and female genital morphology. Nat Commun 2011; 2:374. [DOI: 10.1038/ncomms1379] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/08/2011] [Indexed: 11/09/2022] Open
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34
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Evans JP, Gasparini C, Holwell GI, Ramnarine IW, Pitcher TE, Pilastro A. Intraspecific evidence from guppies for correlated patterns of male and female genital trait diversification. Proc Biol Sci 2011; 278:2611-20. [PMID: 21270040 DOI: 10.1098/rspb.2010.2453] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The role of sexual selection in fuelling genital evolution is becoming increasingly apparent from comparative studies revealing interspecific divergence in male genitalia and evolutionary associations between male and female genital traits. Despite this, we know little about intraspecific variance in male genital morphology, or how male and female reproductive traits covary among divergent populations. Here we address both topics using natural populations of the guppy, Poecilia reticulata, a livebearing fish that exhibits divergent patterns of male sexual behaviour among populations. Initially, we performed a series of mating trials on a single population to examine the relationship between the morphology of the male's copulatory organ (the gonopodium) and the success of forced matings. Using a combination of linear measurements and geometric morphometrics, we found that variation in the length and shape of the gonopodium predicted the success of forced matings in terms of the rate of genital contacts and insemination success, respectively. We then looked for geographical divergence in these traits, since the relative frequency of forced matings tends to be greater in high-predation populations. We found consistent patterns of variation in male genital size and shape in relation to the level of predation, and corresponding patterns of (co)variation in female genital morphology. Together, these data enable us to draw tentative conclusions about the underlying selective pressures causing correlated patterns of divergence in male and female genital traits, which point to a role for sexually antagonistic selection.
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Affiliation(s)
- Jonathan P Evans
- Centre for Evolutionary Biology, School of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia.
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35
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SASABE MASATAKA, TAKAMI YASUOKI, SOTA TEIJI. QTL for the species-specific male and female genital morphologies in Ohomopterus ground beetles. Mol Ecol 2010; 19:5231-9. [DOI: 10.1111/j.1365-294x.2010.04883.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Xu J, Wang Q. Form and nature of precopulatory sexual selection in both sexes of a moth. Naturwissenschaften 2010; 97:617-25. [PMID: 20473478 DOI: 10.1007/s00114-010-0676-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 04/26/2010] [Accepted: 04/27/2010] [Indexed: 01/27/2023]
Abstract
Sexual selection is a process that operates through intrasexual competition and intersexual choice for reproduction in both sexes. Here, we report our work on a polygamous moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), aiming to infer the form and nature of precopulatory sexual selection in males and females. We show that, although a number of traits measured in each sex are correlated with mating success, the primary selection trait in females appears to be abdominal thickness and that in males is aedeagus length. As the female's abdominal thickness is a reliable signal about the number and developmental stage of eggs, males who select females with thicker abdomens for mating will gain reproductive benefit, i.e., fertilizing more mature eggs. For females, earlier maturation of their eggs makes the females more likely to achieve mating earlier in an uncertain world where there is no guarantee that they will find more males in the future. Sexual selection appears to be the important force behind the evolution of fast egg maturation in females. We show that, under a male-biased sex ratio, more than 20% of mating fails within a few minutes after the aedeagus has penetrated into the female's genitalia, suggesting that females can assess the features of the male aedeagus before allowing insemination to occur. Dissection and examination of both sexes suggest that a longer aedeagus enhances mating and fertilization efficiency in this species, supporting the notion that sexual selection is a primary force in the evolution of genital variance.
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Affiliation(s)
- Jin Xu
- Institute of Natural Resources, Massey University, Private Bag 11222, Palmerston North, New Zealand
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37
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PERETTI AV, EBERHARD WG. Cryptic female choice via sperm dumping favours male copulatory courtship in a spider. J Evol Biol 2010; 23:271-81. [DOI: 10.1111/j.1420-9101.2009.01900.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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Song H, Bucheli SR. Comparison of phylogenetic signal between male genitalia and non-genital characters in insect systematics. Cladistics 2010; 26:23-35. [DOI: 10.1111/j.1096-0031.2009.00273.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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39
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Reinhardt K. Natural selection and genital variation: a role for the environment, parasites and sperm ageing? Genetica 2010; 138:119-27. [PMID: 19333766 DOI: 10.1007/s10709-009-9360-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 03/18/2009] [Indexed: 10/21/2022]
Abstract
Male genitalia are more variable between species (and populations) than other organs, and are more morphologically complex in polygamous compared to monogamous species. Therefore, sexual selection has been put forward as the major explanation of genital variation and complexity, in particular cryptic female choice for male copulatory courtship. As cryptic female choice is based on differences between males it is somewhat paradoxical that there is such low within-species variation in male genitalia that they are a prime morphological identification character for animal species. Processes other than sexual selection may also lead to genitalia variation but they have recently become neglected. Here I focus on pleiotropy and natural selection and provide examples how they link genitalia morphology with genital environments. Pleiotropy appears to be important because most studies that specifically tested for pleiotropic effects on genital morphology found them. Natural selection likely favours certain genital morphology over others in various environments, as well as by reducing re-infection with sexually transmitted diseases or reducing the likelihood of fertilisation with aged sperm. Both pleiotropy and natural selection differ locally and between species so may contribute to local variation in genitalia and sometimes variation between monogamous and polygamous species. Furthermore, the multitude of genital environments will lead to a multitude of genital functions via natural selection and pleiotropy, and may also contribute to explaining the complexity of genitalia.
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Affiliation(s)
- Klaus Reinhardt
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
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40
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Evolution of genitalia: theories, evidence, and new directions. Genetica 2010; 138:5-18. [PMID: 19308664 DOI: 10.1007/s10709-009-9358-y] [Citation(s) in RCA: 169] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 02/26/2009] [Indexed: 10/21/2022]
Abstract
Many hypotheses have been proposed to explain why male intromittent genitalia consistently tend to diverge more rapidly than other body traits of the same individuals in a wide range of animal taxa. Currently the two most popular involve sexual selection: sexually antagonistic coevolution (SAC) and cryptic female choice (CFC). A review of the most extensive attempts to discriminate between these two hypotheses indicates that SAC is not likely to have played a major role in explaining this pattern of genital evolution. Promising lines for future, more direct tests of CFC include experimental modification of male genital form and female sensory abilities, analysis of possible male-female dialogues during copulation, and direct observations of genital behavior.
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41
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Dowling DK, Nystrand M, Simmons LW. Maternal effects, but no good or compatible genes for sperm competitiveness in Australian crickets. Evolution 2009; 64:1257-66. [PMID: 20002162 DOI: 10.1111/j.1558-5646.2009.00912.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Explanations for the evolution of polyandry often center on the idea that females garner genetic benefits for their offspring by mating multiply. Furthermore, postcopulatory processes are thought to be fundamental to enabling polyandrous females to screen for genetic quality. Much attention has focused on the potential for polyandrous females to accrue such benefits via a sexy- or good-sperm mechanism, whereby additive variation exists among males in sperm competitiveness. Likewise, attention has focused on an alternative model, in which offspring quality (in this context, the sperm competitiveness of sons) hinges on an interaction between parental haplotypes (genetic compatibility). Sperm competitiveness that is contingent on parental compatibility will exhibit nonadditive genetic variation. We tested these models in the Australian cricket, Teleogryllus oceanicus, using a design that allowed us to partition additive, nonadditive genetic, and parental variance for sperm competitiveness. We found an absence of additive and nonadditive genetic variance in this species, challenging the direct relevance of either model to the evolution of sperm competitiveness in particular, and polyandry in general. Instead, we found maternal effects that were possibly sex-linked or cytoplasmically linked. We also found effects of focal male age on sperm competitiveness, with small increments in age conferring more competitive sperm.
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Affiliation(s)
- Damian K Dowling
- School of Biological Sciences, Monash University, Clayton, 3800, Victoria, Australia.
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42
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Holwell GI, Winnick C, Tregenza T, Herberstein ME. Genital shape correlates with sperm transfer success in the praying mantis Ciulfina klassi (Insecta: Mantodea). Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0879-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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43
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Kuntner M, Coddington JA, Schneider JM. Intersexual arms race? Genital coevolution in nephilid spiders (Araneae, Nephilidae). Evolution 2009; 63:1451-63. [PMID: 19492993 DOI: 10.1111/j.1558-5646.2009.00634.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Genital morphology is informative phylogenetically and strongly selected sexually. We use a recent species-level phylogeny of nephilid spiders to synthesize phylogenetic patterns in nephilid genital evolution that document generalized conflict between male and female interests. Specifically, we test the intersexual coevolution hypothesis by defining gender-specific indices of genital complexity that summarize all relevant and phylogenetically informative traits. We then use independent contrasts to show that male and female genital complexity indices correlate significantly and positively across the phylogeny rather than among sympatric sister species, as predicted by reproductive character displacement. In effect, as females respond to selection for fecundity-driven fitness via giantism and polyandry (perhaps responding to male-biased effective sex ratios), male mechanisms evolve to monopolize females (male monogamy) via opportunistic mating, pre- and postcopulatory mate guarding, and/or plugging of female genitalia to exclude subsequent suitors. In males morphological symptoms of these phenomena range from self-mutilated genitalia to total castration. Although the results are compatible with both recently favored sexual selection hypotheses, sexually antagonistic coevolution, and cryptic female choice, the evidence of strong intersexual conflict and genitalic damage in both sexes is more easily explained as sexually antagonistic coevolution due to an evolutionary arms race.
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Affiliation(s)
- Matjaz Kuntner
- Institute of Biology, Scientific Research Centre, Slovenian Academy of Sciences and Arts, Novi trg 2, P.O. Box 306, SI-1001 Ljubljana, Slovenia
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Ramm SA, Khoo L, Stockley P. Sexual selection and the rodent baculum: an intraspecific study in the house mouse (Mus musculus domesticus). Genetica 2009; 138:129-37. [DOI: 10.1007/s10709-009-9385-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Accepted: 07/02/2009] [Indexed: 11/29/2022]
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45
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BRICEÑO RD, EBERHARD WG. Experimental modifications imply a stimulatory function for male tsetse fly genitalia, supporting cryptic female choice theory. J Evol Biol 2009; 22:1516-25. [DOI: 10.1111/j.1420-9101.2009.01761.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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46
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Eberhard WG. Postcopulatory sexual selection: Darwin's omission and its consequences. Proc Natl Acad Sci U S A 2009; 106 Suppl 1:10025-32. [PMID: 19528642 PMCID: PMC2702800 DOI: 10.1073/pnas.0901217106] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In one of his few major oversights, Darwin failed to appreciate that male-male competition and sexual selection can continue even after copulation has begun. The postcopulatory equivalents of both direct male-male battles (sperm competition) and female choice (cryptic female choice) occur within the female's body. Recognition of this hidden, but intense, sexual competition provides new insights into a variety of fields. These include the hyperdiverse and paradoxically elaborate morphology of both sperm and male genitalia, the equally puzzling and elaborate morphology of nongenitalic male structures that are specialized to grasp and stimulate females, powerful manipulative effects of substances in male semen on female reproductive physiology, paradoxical male courtship behavior that occurs after copulation has already begun, variability in parental investments, and the puzzlingly complex and diverse interactions between sperm and female products that surround animal eggs and between male gametophytes and female tissues in flowering plants. Many bizarre traits are involved, including male genitalia that are designed to explode or fall apart during copulation leaving behind parts within the female, male genitalia that "sing" during copulation, potent seminal products that invade the female's body cavity and her nervous system to influence her behavior, and a virtual Kama Sutra of courtship behavior performed after rather than before genital coupling, including male-female dialogues during copulation.
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Affiliation(s)
- William G Eberhard
- Smithsonian Tropical Research Institute and Escuela de Biologia, Universidad de Costa Rica, San José, Costa Rica.
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47
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Han CS, Jablonski PG. Female genitalia concealment promotes intimate male courtship in a water strider. PLoS One 2009; 4:e5793. [PMID: 19516886 PMCID: PMC2686155 DOI: 10.1371/journal.pone.0005793] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 04/30/2009] [Indexed: 11/19/2022] Open
Abstract
Violent coercive mating initiation is typical for animals with sexual conflict over mating. In these species, the coevolutionary arms-race between female defenses against coercive mating and male counter-adaptations for increased mating success leads to coevolutionary chases of male and female traits that influence the mating. It has been controversial whether one of the sexes can evolve traits that allow them to “win” this arms race. Here, we use morphological analysis (traditional and scanning electron micrographs), laboratory experiments and comparative methods to show how females of a species characterized by typical coercive mating initiation appear to “win” a particular stage of the sexual conflict by evolving morphology to hide their genitalia from direct, forceful access by males. In an apparent response to the female morphological adaptation, males of this species added to their typically violent coercive mounting of the female new post-mounting, pre-copulatory courtship signals produced by tapping the water's surface with the mid-legs. These courtship signals are intimate in the sense that they are aimed at the female, on whom the male is already mounted. Females respond to the signals by exposing their hidden genitalia for copulatory intromission. Our results indicate that the apparent victory of coevolutionary arms race by one sex in terms of morphology may trigger evolution of a behavioral phenotype in the opposite sex.
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Affiliation(s)
- Chang S. Han
- Laboratory of Behavioral Ecology and Evolution, School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Piotr G. Jablonski
- Laboratory of Behavioral Ecology and Evolution, School of Biological Sciences, Seoul National University, Seoul, South Korea
- Center for Ecological Research, Polish Academy of Sciences, Dziekanow Lesny, Lomianki, Poland
- * E-mail:
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48
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Kuntner M, Kralj-Fišer S, Schneider JM, Li D. Mate plugging via genital mutilation in nephilid spiders: an evolutionary hypothesis. J Zool (1987) 2009. [DOI: 10.1111/j.1469-7998.2008.00533.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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EBERHARD W, RODRIGUEZ RL, POLIHRONAKIS M. Pitfalls in understanding the functional significance of genital allometry. J Evol Biol 2009; 22:435-45. [DOI: 10.1111/j.1420-9101.2008.01654.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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50
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POLIHRONAKIS MAXI. Hierarchical comparative analysis of genetic and genitalic geographical structure: testing patterns of male and female genital evolution in the scarab beetle Phyllophaga hirticula (Coleoptera: Scarabaeidae). Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.2008.01111.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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