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Lamar SK, Nelson NJ, Ormsby DK. Characterization of sperm and implications for male fertility in the last of the Rhynchocephalians. CONSERVATION PHYSIOLOGY 2023; 11:coad071. [PMID: 37663926 PMCID: PMC10470484 DOI: 10.1093/conphys/coad071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/08/2023] [Accepted: 08/16/2023] [Indexed: 09/05/2023]
Abstract
Managing a species of conservation concern can be best achieved when there is information on the reproductive physiology of both sexes available; however, many species lack this critical, baseline information. One such species, the tuatara (Sphenodon punctatus), is the last surviving member of one of the four reptile orders (Rhynchocephalia) and is the only reptile known to lack a male intromittent organ. Culturally and evolutionarily significant, the conservation of this species is a global priority for the maintenance of biodiversity. In light of this, we characterized the morphology, viability and swim speed of mature tuatara sperm for the first time. We found that tuatara sperm are filiform and bear the remarkably conserved three-part sperm structure seen across the animal kingdom. Tuatara sperm are long (mean total length 166 μm), with an approximate head:midpiece:tail ratio of 15:1:17. While tuatara sperm are capable of high levels of within-mating viability (94.53%), the mean viability across all samples was 58.80%. Finally, tuatara sperm had a mean curvilinear velocity swim speed (μ × s - 1) of 82.28. At the population level, there were no differences in viability or mean swim speed between sperm collected from a male's first mating of a season and repeat matings; however, the maximum sperm swim speed increased in observed repeated matings relative to first matings. Interestingly, faster sperm samples had shorter midpieces, but had greater viability and longer head and tail sections. This work expands our understanding of male reproductive characteristics and their variation to a new order, provides wild references for the assessment of captive individuals, lays the groundwork for potential assisted reproductive techniques and highlights variation in male reproductive potential as an important factor for consideration in future conservation programs for this unique species.
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Affiliation(s)
- Sarah K Lamar
- School of Biological Sciences, Victoria University of Wellington, Level 2 Te Toki a Rata Building, Wellington 6012, New Zealand
- Centre for Biodiversity and Restoration Ecology, Victoria University of Wellington, Level 2 Te Toki a Rata Building, Wellington 6012, New Zealand
| | - Nicola J Nelson
- School of Biological Sciences, Victoria University of Wellington, Level 2 Te Toki a Rata Building, Wellington 6012, New Zealand
- Centre for Biodiversity and Restoration Ecology, Victoria University of Wellington, Level 2 Te Toki a Rata Building, New Zealand
| | - Diane K Ormsby
- School of Biological Sciences, Victoria University of Wellington, Level 2 Te Toki a Rata Building, Wellington 6012, New Zealand
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2
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Lipshutz SE, Torneo SJ, Rosvall KA. How Female-Female Competition Affects Male-Male Competition: Insights into Postcopulatory Sexual Selection from Socially Polyandrous Species. Am Nat 2023; 201:460-471. [PMID: 36848510 DOI: 10.1086/722799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractSexual selection is a major driver of trait variation, and the intensity of male competition for mating opportunities has been linked with sperm size across diverse taxa. Mating competition among females may also shape the evolution of sperm traits, but the effect of the interplay between female-female competition and male-male competition on sperm morphology is not well understood. We evaluated variation in sperm morphology in two species with socially polyandrous mating systems, in which females compete to mate with multiple males. Northern jacanas (Jacana spinosa) and wattled jacanas (J. jacana) vary in their degree of social polyandry and sexual dimorphism, suggesting species differences in the intensity of sexual selection. We compared mean and variance in sperm head, midpiece, and tail length between species and breeding stages because these measures have been associated with the intensity of sperm competition. We found that the species with greater polyandry, northern jacana, has sperm with longer midpieces and tails as well as marginally lower intraejaculate variation in tail length. Intraejaculate variation was also significantly lower in copulating males than in incubating males, suggesting flexibility in sperm production as males cycle between breeding stages. Our results indicate that stronger female-female competition for mating opportunities may also shape more intense male-male competition by selecting for longer and less variable sperm traits. These findings extend frameworks developed in socially monogamous species to reveal that sperm competition may be an important evolutionary force layered atop female-female competition for mates.
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3
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Cramer ERA, Grønstøl G, Lifjeld JT. Flagellum tapering and midpiece volume in songbird spermatozoa. J Morphol 2022; 283:1577-1589. [PMID: 36260518 PMCID: PMC9828668 DOI: 10.1002/jmor.21524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 01/19/2023]
Abstract
In contrast to numerous studies on spermatozoa length, relatively little work focuses on the width of spermatozoa, and particularly the width of the midpiece and flagellum. In flagellated spermatozoa, the flagellum provides forward thrust while energy may be provided via mitochondria in the midpiece and/or through glycolysis along the flagellum itself. Longer flagella may be able to provide greater thrust but may also require stronger structural features and more or larger mitochondria to supply sufficient energy. Here, we use scanning electron microscopy to investigate the ultrastructure of spermatozoa from 55 passerine species in 26 taxonomic families in the Passerides infraorder. Our data confirm the qualitative observation that the flagellum tapers along its length, and we show that longer flagella are wider at the neck. This pattern is similar to mammals, and likely reflects the need for longer cells to be stronger against shearing forces. We further estimate the volume of the mitochondrial helix and show that it correlates well with midpiece length, supporting the use of midpiece length as a proxy for mitochondrial volume, at least in between-species studies where midpiece length is highly variable. These results provide important context for understanding the evolutionary correlations among different sperm cell components and dimensions.
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4
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Cowart JR, Collins DM, Stanton DL, van der Horst G, Larkin IV. Morphometric and structural analysis of Florida manatee spermatozoa. Anat Rec (Hoboken) 2022; 305:446-461. [PMID: 33890720 PMCID: PMC9290592 DOI: 10.1002/ar.24645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 11/26/2022]
Abstract
Sperm characteristics, such as sperm morphology and sperm morphometry are important in assessing sperm quality. This is especially important for the management and conservation of endangered and exotic species, like the Florida manatee, where information of this nature is extremely limited. In this study, we fill this knowledge gap to better understand the reproductive physiology of Florida manatees by conducting the first extensive analysis of sperm morphometry and ultrastructure. Sperm were retrieved from the vas deferens of nine recently deceased Florida manatees. Computer-aided sperm morphology analysis (CASMA) was used for morphometric analysis and laser-scanning confocal microscopy and electron microscopy were used for structural and ultrastructural characterization. Our findings reveal new morphometric and structural data for the Florida manatee spermatozoon. Twelve morphometric features of Florida manatee sperm were quantified with some approximately 1.5-2 times larger than those previously reported. Ultrastructurally, the Florida manatee spermatozoon followed a mammalian structural pattern with an ovate-shaped head, midpiece containing 84-90 mitochondria, and a flagellum. However, unique ultrastructural features were identified. Distinct, rectangular-like enlargement of four outer dense fibers surrounding the axoneme was evident, which may provide additional tensile strength to counteract the forces on sperm transiting the female reproductive tract. Likewise, strong localization of F-actin fibers within the midpiece may function to maintain sperm integrity within the female reproductive tract. These findings highlight the potential effects of sexual selective pressures on sperm size and structure in the Florida manatee and provide avenues for research on the occurrence of sperm competition in this species.
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Affiliation(s)
- Jonathan R. Cowart
- Aquatic Animal Health ProgramCollege of Veterinary Medicine, University of FloridaGainesvilleFloridaUSA
| | - Danielle M. Collins
- Department of Animal SciencesCollege of Agricultural and Life Sciences, University of FloridaGainesvilleFloridaUSA
| | - Daniel L. Stanton
- Department of Animal SciencesCollege of Agricultural and Life Sciences, University of FloridaGainesvilleFloridaUSA
- University of Florida Institute of Food and Agricultural Sciences, Citrus Research and Education CenterLake AlfredFloridaUSA
| | | | - Iskande V. Larkin
- Aquatic Animal Health ProgramCollege of Veterinary Medicine, University of FloridaGainesvilleFloridaUSA
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5
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Durrant KL, Reader T, Symonds MRE. Pre- and post-copulatory traits working in concert: sexual dichromatism in passerines is associated with sperm morphology. Biol Lett 2020; 16:20190568. [PMID: 31937213 DOI: 10.1098/rsbl.2019.0568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Passerine birds produce costly traits under intense sexual selection, including elaborate sexually dichromatic plumage and sperm morphologies, to compete for fertilizations. Plumage and sperm traits vary markedly among species, but it is unknown if this reflects a trade-off between pre- and post-copulatory investment under strong sexual selection producing negative trait covariance, or variation in the strength of sexual selection among species producing positive covariance. Using phylogenetic regression, we analysed datasets describing plumage and sperm morphological traits for 278 passerine species. We found a significant positive relationship between sperm midpiece length and male plumage elaboration and sexual dichromatism. We did not find a relationship between plumage elaboration and testes mass. Our results do not support a trade-off between plumage and sperm traits, but may be indicative of variance among species in the strength of sexual selection to produce both brightly coloured plumage and costly sperm traits.
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Affiliation(s)
- Kate L Durrant
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Tom Reader
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Matthew R E Symonds
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia
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6
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Rowley A, Locatello L, Kahrl A, Rego M, Boussard A, Garza-Gisholt E, Kempster RM, Collin SP, Giacomello E, Follesa MC, Porcu C, Evans JP, Hazin F, Garcia-Gonzalez F, Daly-Engel T, Mazzoldi C, Fitzpatrick JL. Sexual selection and the evolution of sperm morphology in sharks. J Evol Biol 2019; 32:1027-1035. [PMID: 31250483 DOI: 10.1111/jeb.13501] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 06/16/2019] [Accepted: 06/22/2019] [Indexed: 01/18/2023]
Abstract
Post-copulatory sexual selection, and sperm competition in particular, is a powerful selective force shaping the evolution of sperm morphology. Although mounting evidence suggests that post-copulatory sexual selection influences the evolution of sperm morphology among species, recent evidence also suggests that sperm competition influences variation in sperm morphology at the intraspecific level. However, contradictory empirical results and limited taxonomic scope have led to difficulty in assessing the generality of sperm morphological responses to variation in the strength of sperm competition. Here, we use phylogenetically controlled analyses to explore the effects of sperm competition on sperm morphology and variance in sharks, a basal vertebrate group characterized by wide variation in rates of multiple mating by females, and consequently sperm competition risk. Our analyses reveal that shark species experiencing greater levels of sperm competition produce sperm with longer flagella and that sperm flagellum length is less variable in species under higher sperm competition risk. In contrast, neither the length of the sperm head and midpiece nor variation in sperm head and midpiece length was associated with sperm competition risk. Our findings demonstrate that selection influences both the inter- and intraspecific variation in sperm morphology and suggest that the flagellum is an important target of sexual selection in sharks. These findings provide important insight into patterns of selection on the ejaculate in a basal vertebrate lineage.
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Affiliation(s)
- Amy Rowley
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Lisa Locatello
- Department of Biology, University of Padova, Padua, Italy
| | - Ariel Kahrl
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Mariana Rego
- Laboratório de Histologia Animal, Departamento de Morfologia e Fisiologia Animal, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Annika Boussard
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Eduardo Garza-Gisholt
- Oceans Graduate School, The University of Western Australia, Crawley, Western Australia, Australia.,The UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia, Australia
| | - Ryan M Kempster
- Oceans Graduate School, The University of Western Australia, Crawley, Western Australia, Australia.,The UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia, Australia
| | - Shaun P Collin
- Oceans Graduate School, The University of Western Australia, Crawley, Western Australia, Australia.,The UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia, Australia.,School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Eva Giacomello
- MARE - Marine and Environmental Sciences Centre, IMAR- Institute of the Sea, OKEANOS Centre- University of the Azores, Horta, Portugal
| | - Maria C Follesa
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Cristina Porcu
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Jonathan P Evans
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Fabio Hazin
- Laboratório de Histologia Animal, Departamento de Morfologia e Fisiologia Animal, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Francisco Garcia-Gonzalez
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia.,Estacion Biologica de Doñana-CSIC, Sevilla, Spain
| | - Toby Daly-Engel
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, Melbourne, FL, USA
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7
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Turani B, Aliko V, Shkembi E. Characterization of Albanian water frog, Pelophylax shqipericus, sperm traits and morphology, by using phase contrast microscopy. Microsc Res Tech 2019; 82:1802-1809. [PMID: 31313452 DOI: 10.1002/jemt.23346] [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: 03/25/2019] [Revised: 05/28/2019] [Accepted: 06/13/2019] [Indexed: 11/10/2022]
Abstract
Mature spermatozoa traits and morphology of endangered Albanian water frog, Pelophylax shqipericus, have been characterized for the first time through phase contrast microscopy, as part of successful implementation of in vitro fertilization technique for this species. The basic morphology of P. shqipericus spermatozoa consists of an elongated, thick, smooth-edged, and solid-staining head, continuing with a thin and long tail which usually extends 2.48 times the head length. The acrosome was not clearly discernible so the measurements were done on the head as a whole, while the middle section was better visible. Average length of head, including the acrosome and midsection was estimated to be 11.78 μm ± 0.32, while the tail length resulted 29.24 ± 1.75 μm. The average thickness of the head was shown to be 3.45 μm. The total sperm length resulted to be 41.02 ± 1.83 μm. The average sperm concentration was estimated of 25.5 × 106 /ml. Sperm amount, survival rate and motility were also measured. The sperm survival rate was maximal immediately after preparation of the suspension and tended to decrease over time of storage, reaching 50% after 72 hr. Decreased sperm motility seemed to follow the same trend as sperm viability. Sperm traits resulted to be very similar both in size and in shape with those of "Lessonae" frog group, one of the lineages of Western Palearctic species complex, suggesting a strong phylogenetic relationship among these species.
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Affiliation(s)
- Blerta Turani
- University of Tirana, Faculty of Natural Sciences, Tirana, Albania
| | - Valbona Aliko
- University of Tirana, Faculty of Natural Sciences, Tirana, Albania
| | - Entela Shkembi
- Semiology Laboratory, Medical Center, Dani Andrology, Tirana, Albania
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8
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Langen K, Thünken T, Klemm J, Sandmann S, Bakker TCM. Sperm size is negatively related to relative testis size in West African riverine cichlid fishes. Naturwissenschaften 2019; 106:30. [PMID: 31147792 DOI: 10.1007/s00114-019-1622-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 10/26/2022]
Abstract
Fishes show a great diversity of mating systems and fertilization mechanisms. This diversity creates an enormous potential for sperm competition. Typically, monogamous species face a low risk of sperm competition and invest less into sperm, and thus show smaller relative testis mass compared to polygamous species with high sperm competition. In cichlids, sperm competition risk is very variable. In lacustrine East African cichlids, large sperm are interpreted as an adaptation to sperm competition, as in those species sperm length correlates with sperm swimming speed. The aim of the present study was to examine variation in sperm and testis traits of substrate breeding cichlids from West African river systems and its relationship to sperm competition. Therefore, sperm traits (total sperm size, flagellum-, midpiece-, and head size) and sperm number were related to the gonadosomatic index (GSI), an indicator of sperm competition, in eight species of two large informal tribes, the chromidotilapiines and the haplotilapiines. We found significant differences between species in all examined sperm traits, sperm number, and GSI with pronounced differences between chromidotilapiines and haplotilapiines. We used a generalized least-squares approach to control for non-independence of data. GSI was positively correlated with sperm number but negatively correlated with total sperm size (also negatively with the flagellum and head size but not significantly with midpiece size). Sperm number and sperm size were negatively correlated suggesting a trade-off between sperm size and quality. Our results suggest that large sperm can evolve in species with relatively low sperm expenditure and probably in absence of high sperm competition between males.
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Affiliation(s)
- Kathrin Langen
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121, Bonn, Germany. .,Zoological Research Museum Alexander Koenig, Leibniz Institute for Animal Biodiversity, Adenauerallee 160/162, 53113, Bonn, Germany.
| | - Timo Thünken
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121, Bonn, Germany
| | - Janine Klemm
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121, Bonn, Germany
| | - Sarah Sandmann
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121, Bonn, Germany
| | - Theo C M Bakker
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121, Bonn, Germany
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9
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Manier MK, Welch G, Van Nispen C, Bakst MR, Long J. Low-mobility sperm phenotype in the domestic turkey: Impact on sperm morphometry and early embryonic death. Reprod Domest Anim 2019; 54:613-621. [PMID: 30650207 DOI: 10.1111/rda.13403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/02/2019] [Indexed: 11/28/2022]
Abstract
The sperm mobility assay measures the ability of sperm to swim through a dense layer of Accudenz® , and the sperm mobility phenotype has been shown to predict fertility and other sperm performance traits in roosters and turkeys. In this study, we examined turkey sperm morphometry and rates of early embryonic death associated with high- and low-mobility semen. We also assessed whether the hypo-osmotic stress test, which evaluates the structural integrity of the sperm plasma membrane, may be used as a faster and simpler assay for sperm mobility and viability. We confirmed previous work that found that high-mobility sperm are faster and swim more linearly than low-mobility sperm, and that mobility traits were repeatable within males. In contrast to previous studies, we did not find higher rates of fertility, but low-mobility sperm was associated with higher rates of early embryonic death, though this trend was not significant. High-mobility sperm had longer sperm heads, explained by longer nuclei, despite shorter acrosomes. Although these sperm were faster, midpiece length and flagellum length did not differ between high- and low-mobility sperm. Finally, mobility was not found to be associated with sperm performance in the hypo-osmotic stress test.
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Affiliation(s)
- Mollie K Manier
- Biological Sciences, The George Washington University, Washington, District of Columbia
| | - Glenn Welch
- Animal Biosciences and Biotechnology Laboratory, Agricultural Research Service, USDA, Beltsville, Maryland
| | - Christiaan Van Nispen
- Biological Sciences, The George Washington University, Washington, District of Columbia
| | - Murray R Bakst
- Animal Biosciences and Biotechnology Laboratory, Agricultural Research Service, USDA, Beltsville, Maryland
| | - Julie Long
- Animal Biosciences and Biotechnology Laboratory, Agricultural Research Service, USDA, Beltsville, Maryland
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10
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Kahrl AF, Johnson MA, Cox RM. Rapid evolution of testis size relative to sperm morphology suggests that post-copulatory selection targets sperm number in Anolis lizards. J Evol Biol 2019; 32:302-309. [PMID: 30659673 DOI: 10.1111/jeb.13414] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/14/2018] [Accepted: 01/14/2019] [Indexed: 11/28/2022]
Abstract
Post-copulatory sexual selection is thought to be responsible for much of the extraordinary diversity in sperm morphology across metazoans. However, the extent to which post-copulatory selection targets sperm morphology versus sperm production is generally unknown. To address this issue, we simultaneously characterized the evolution of sperm morphology (length of the sperm head, midpiece and flagellum) and testis size (a proxy for sperm production) across 26 species of Anolis lizards, a group in which sperm competition is likely. We found that the length of the sperm midpiece has evolved 2-3 times faster than that of the sperm head or flagellum, suggesting that midpiece size may be the most important aspect of sperm morphology with respect to post-copulatory sexual selection. However, testis size has evolved faster than any aspect of sperm morphology or body size, supporting the hypothesis that post-copulatory sexual selection acts more strongly upon sperm production than upon sperm morphology. Likewise, evolutionary increases in testis size, which typically indicate increased sperm competition, are not associated with predictable changes in sperm morphology, suggesting that any effects of post-copulatory selection on sperm morphology are either weak or variable in direction across anoles. Collectively, our results suggest that sperm production is the primary target of post-copulatory sexual selection in this lineage.
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Affiliation(s)
- Ariel F Kahrl
- Zoologiska institutionen: Etologi, Stockholm University, Stockholm, Sweden.,Department of Biology, University of Virginia, Charlottesville, Virginia
| | | | - Robert M Cox
- Department of Biology, University of Virginia, Charlottesville, Virginia
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11
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Rowley AG, Daly-Engel TS, Fitzpatrick JL. Testes size increases with sperm competition risk and intensity in bony fish and sharks. Behav Ecol 2018. [DOI: 10.1093/beheco/ary174] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Amy G Rowley
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Toby S Daly-Engel
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, USA
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12
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Rojas Mora A, Meniri M, Ciprietti S, Helfenstein F. Is sperm morphology functionally related to sperm swimming ability? A case study in a wild passerine bird with male hierarchies. BMC Evol Biol 2018; 18:142. [PMID: 30231935 PMCID: PMC6146611 DOI: 10.1186/s12862-018-1260-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 09/11/2018] [Indexed: 11/21/2022] Open
Abstract
Background Sexual selection continues after copulation via either sperm competition or cryptic female choice, and favors sperm traits that maximize sperm competitiveness. Both sperm swimming velocity and longevity are important determinants of the outcome of sperm competition. Theoretically, sperm morphology can influence sperm velocity at least in three different non-exclusive ways: (i) longer sperm may generate more propelling thrust, (ii) bigger midpieces may produce more energy, and/or (iii) larger flagella or mid-pieces relative to the head size may compensate for the drag forces around the head. A growing number of studies have investigated the relationship of sperm morphology with sperm performance, which remains equivocal at both the inter- and intra-specific levels. Here, we used House Sparrows to test the functional relationship between sperm morphology with sperm velocity and longevity. Based on a previous study showing that sperm swimming ability covaries with social rank, we predicted that —if a functional relationship exists—1) sperm morphology should differ across social ranks, and 2) correlations between sperm morphology and sperm velocity and/or sperm longevity should be constant across social ranks. Results We found no differences in sperm morphology across social ranks. Moreover, we found that sperm morphology may be correlated with sperm velocity, but such relationship varied across social ranks. This result contradicts the hypothesis of a functional relationship between sperm morphology and sperm performance. Finally, after experimentally manipulating social ranks, we observed that relationships between sperm morphology and sperm velocity and/or sperm longevity disappeared or changed direction. Conclusions We suggest that in species with internal fertilization, while sperm morphology is likely constrained by the morphology of the female sperm storage organs, selection may act upon physiological traits that enhance sperm performance. Hence, these two selection forces could decouple sperm performance from sperm morphology. Electronic supplementary material The online version of this article (10.1186/s12862-018-1260-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alfonso Rojas Mora
- Laboratory of Evolutionary Ecophysiology, Institute of Biology, Faculty of Sciences, University of Neuchatel, Neuchatel, Switzerland. .,Present Address: Laboratory of Ecology and Epidemiology of Parasites, Institute of Biology, Faculty of Sciences, University of Neuchatel, Rue Emile-Argand 11, 2000, Neuchatel, Switzerland.
| | - Magali Meniri
- Laboratory of Evolutionary Ecophysiology, Institute of Biology, Faculty of Sciences, University of Neuchatel, Neuchatel, Switzerland
| | - Sabrina Ciprietti
- Laboratory of Evolutionary Ecophysiology, Institute of Biology, Faculty of Sciences, University of Neuchatel, Neuchatel, Switzerland
| | - Fabrice Helfenstein
- Laboratory of Evolutionary Ecophysiology, Institute of Biology, Faculty of Sciences, University of Neuchatel, Neuchatel, Switzerland
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13
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Affiliation(s)
- Heidi S Fisher
- Department of Biology, University of Maryland, College Park, MD, 20742, USA.
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14
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Girndt A, Cockburn G, Sánchez-Tójar A, Løvlie H, Schroeder J. Method matters: Experimental evidence for shorter avian sperm in faecal compared to abdominal massage samples. PLoS One 2017; 12:e0182853. [PMID: 28813481 PMCID: PMC5559096 DOI: 10.1371/journal.pone.0182853] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/25/2017] [Indexed: 11/19/2022] Open
Abstract
Birds are model organisms in sperm biology. Previous work in zebra finches, suggested that sperm sampled from males' faeces and ejaculates do not differ in size. Here, we tested this assumption in a captive population of house sparrows, Passer domesticus. We compared sperm length in samples from three collection techniques: female dummy, faecal and abdominal massage samples. We found that sperm were significantly shorter in faecal than abdominal massage samples, which was explained by shorter heads and midpieces, but not flagella. This result might indicate that faecal sampled sperm could be less mature than sperm collected by abdominal massage. The female dummy method resulted in an insufficient number of experimental ejaculates because most males ignored it. In light of these results, we recommend using abdominal massage as a preferred method for avian sperm sampling. Where avian sperm cannot be collected by abdominal massage alone, we advise controlling for sperm sampling protocol statistically.
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Affiliation(s)
- Antje Girndt
- Evolutionary Biology, Max Planck Institute for Ornithology, Seewiesen, Germany
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, United Kingdom
- International Max-Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, Konstanz, Germany
| | - Glenn Cockburn
- Evolutionary Biology, Max Planck Institute for Ornithology, Seewiesen, Germany
- International Max-Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, Konstanz, Germany
| | - Alfredo Sánchez-Tójar
- Evolutionary Biology, Max Planck Institute for Ornithology, Seewiesen, Germany
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, United Kingdom
- International Max-Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, Konstanz, Germany
| | - Hanne Løvlie
- IFM Biology, Linköping University, Linköping, Sweden
| | - Julia Schroeder
- Evolutionary Biology, Max Planck Institute for Ornithology, Seewiesen, Germany
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, United Kingdom
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15
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A sex-chromosome inversion causes strong overdominance for sperm traits that affect siring success. Nat Ecol Evol 2017; 1:1177-1184. [PMID: 29046576 DOI: 10.1038/s41559-017-0236-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 06/06/2017] [Indexed: 01/23/2023]
Abstract
Male reproductive success depends on the competitive ability of sperm to fertilize the ova, which should lead to strong selection on sperm characteristics. This raises the question of how heritable variation in sperm traits is maintained. Here we show that in zebra finches (Taeniopygia guttata) nearly half of the variance in sperm morphology is explained by an inversion on the Z chromosome with a 40% allele frequency in the wild. The sperm of males that are heterozygous for the inversion had the longest midpieces and the highest velocity. Furthermore, such males achieved the highest fertility and the highest siring success, both within-pair and extra-pair. Males homozygous for the derived allele show detrimental sperm characteristics and the lowest siring success. Our results suggest heterozygote advantage as the mechanism that maintains the inversion polymorphism and hence variance in sperm design and in fitness.
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16
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Rheubert J, Messak JA, Siegel DS, Gribbins KM, Trauth SE, Sever DM. Inter- and intraspecific variation in sperm morphology of Sceloporus consobrinus and Sceloporus undulatus (Squamata: Phrynosomatidae). Biol J Linn Soc Lond 2017. [DOI: 10.1093/biolinnean/blw043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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17
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Godwin JL, Vasudeva R, Michalczyk Ł, Martin OY, Lumley AJ, Chapman T, Gage MJG. Experimental evolution reveals that sperm competition intensity selects for longer, more costly sperm. Evol Lett 2017; 1:102-113. [PMID: 30283643 PMCID: PMC6089504 DOI: 10.1002/evl3.13] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 04/24/2017] [Accepted: 05/02/2017] [Indexed: 12/12/2022] Open
Abstract
It is the differences between sperm and eggs that fundamentally underpin the differences between the sexes within reproduction. For males, it is theorized that widespread sperm competition leads to selection for investment in sperm numbers, achieved by minimizing sperm size within limited resources for spermatogenesis in the testis. Here, we empirically examine how sperm competition shapes sperm size, after more than 77 generations of experimental selection of replicate lines under either high or low sperm competition intensities in the promiscuous flour beetle Tribolium castaneum. After this experimental evolution, populations had diverged significantly in their sperm competitiveness, with sperm in ejaculates from males evolving under high sperm competition intensities gaining 20% greater paternity than sperm in ejaculates from males that had evolved under low sperm competition intensity. Males did not change their relative investment into sperm production following this experimental evolution, showing no difference in testis sizes between high and low intensity regimes. However, the more competitive males from high sperm competition intensity regimes had evolved significantly longer sperm and, across six independently selected lines, there was a significant association between the degree of divergence in sperm length and average sperm competitiveness. To determine whether such sperm elongation is costly, we used dietary restriction experiments, and revealed that protein-restricted males produced significantly shorter sperm. Our findings therefore demonstrate that sperm competition intensity can exert positive directional selection on sperm size, despite this being a costly reproductive trait.
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Affiliation(s)
- Joanne L. Godwin
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | - Ramakrishnan Vasudeva
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | | | | | - Alyson J. Lumley
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | - Tracey Chapman
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | - Matthew J. G. Gage
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
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18
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Fisher HS, Jacobs-Palmer E, Lassance JM, Hoekstra HE. The genetic basis and fitness consequences of sperm midpiece size in deer mice. Nat Commun 2016; 7:13652. [PMID: 27910854 PMCID: PMC5146288 DOI: 10.1038/ncomms13652] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 10/20/2016] [Indexed: 11/09/2022] Open
Abstract
An extensive array of reproductive traits varies among species, yet the genetic mechanisms that enable divergence, often over short evolutionary timescales, remain elusive. Here we examine two sister-species of Peromyscus mice with divergent mating systems. We find that the promiscuous species produces sperm with longer midpiece than the monogamous species, and midpiece size correlates positively with competitive ability and swimming performance. Using forward genetics, we identify a gene associated with midpiece length: Prkar1a, which encodes the R1α regulatory subunit of PKA. R1α localizes to midpiece in Peromyscus and is differentially expressed in mature sperm of the two species yet is similarly abundant in the testis. We also show that genetic variation at this locus accurately predicts male reproductive success. Our findings suggest that rapid evolution of reproductive traits can occur through cell type-specific changes to ubiquitously expressed genes and have an important effect on fitness. Across species there are large changes in sperm morphology, yet how and why is unclear. Here, the authors show in Peromyscus mice, that the sperm midpiece length influences swimming speed and male fertility, and is regulated by cell-type specific expression of a ubiquitously expressed gene, Prkar1a.
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Affiliation(s)
- Heidi S Fisher
- Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA
| | - Emily Jacobs-Palmer
- Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA
| | - Jean-Marc Lassance
- Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA
| | - Hopi E Hoekstra
- Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA
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19
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Lifjeld JT, Anmarkrud JA, Calabuig P, Cooper JEJ, Johannessen LE, Johnsen A, Kearns AM, Lachlan RF, Laskemoen T, Marthinsen G, Stensrud E, Garcia-del-Rey E. Species-level divergences in multiple functional traits between the two endemic subspecies of Blue Chaffinches Fringilla teydea in Canary Islands. BMC ZOOL 2016. [DOI: 10.1186/s40850-016-0008-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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20
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Cramer ERA, Stensrud E, Marthinsen G, Hogner S, Johannessen LE, Laskemoen T, Eybert MC, Slagsvold T, Lifjeld JT, Johnsen A. Sperm performance in conspecific and heterospecific female fluid. Ecol Evol 2016; 6:1363-77. [PMID: 26855769 PMCID: PMC4733106 DOI: 10.1002/ece3.1977] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/08/2015] [Accepted: 01/03/2016] [Indexed: 12/11/2022] Open
Abstract
Divergent sexual selection within allopatric populations may result in divergent sexual phenotypes, which can act as reproductive barriers between populations upon secondary contact. This hypothesis has been most tested on traits involved in precopulatory sexual selection, with less work focusing on traits that act after copulation and before fertilization (i.e., postcopulatory prezygotic traits), particularly in internally fertilizing vertebrates. However, postcopulatory sexual selection within species can also drive trait divergence, resulting in reduced performance of heterospecific sperm within the female reproductive tract. Such incompatibilities, arising as a by‐product of divergent postcopulatory sexual selection in allopatry, can represent reproductive barriers, analogous to species‐assortative mating preferences. Here, we tested for postcopulatory prezygotic reproductive barriers between three pairs of taxa with diverged sperm phenotypes and moderate‐to‐high opportunity for postcopulatory sexual selection (barn swallows Hirundo rustica versus sand martins Riparia riparia, two subspecies of bluethroats, Luscinia svecica svecica versus L. s. namnetum, and great tits Parus major versus blue tits Cyanistes caeruleus). We tested sperm swimming performance in fluid from the outer reproductive tract of females, because the greatest reduction in sperm number in birds occurs as sperm swim across the vagina. Contrary to our expectations, sperm swam equally well in fluid from conspecific and heterospecific females, suggesting that postcopulatory prezygotic barriers do not act between these taxon pairs, at this stage between copulation and fertilization. We therefore suggest that divergence in sperm phenotypes in allopatry is insufficient to cause widespread postcopulatory prezygotic barriers in the form of impaired sperm swimming performance in passerine birds.
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Affiliation(s)
- Emily R A Cramer
- Natural History Museum University of Oslo PO Box 1172 Blindern 0318 Oslo Norway
| | - Even Stensrud
- Natural History Museum University of Oslo PO Box 1172 Blindern 0318 Oslo Norway
| | - Gunnhild Marthinsen
- Natural History Museum University of Oslo PO Box 1172 Blindern 0318 Oslo Norway
| | - Silje Hogner
- Natural History Museum University of Oslo PO Box 1172 Blindern 0318 Oslo Norway
| | | | - Terje Laskemoen
- Natural History Museum University of Oslo PO Box 1172 Blindern 0318 Oslo Norway
| | | | - Tore Slagsvold
- Department of Biosciences Center for Ecological and Evolutionary Synthesis (CEES) University of Oslo PO Box 1066 Blindern 0316 Oslo Norway
| | - Jan T Lifjeld
- Natural History Museum University of Oslo PO Box 1172 Blindern 0318 Oslo Norway
| | - Arild Johnsen
- Natural History Museum University of Oslo PO Box 1172 Blindern 0318 Oslo Norway
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21
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Majhi RK, Kumar A, Yadav M, Kumar P, Maity A, Giri SC, Goswami C. Light and electron microscopic study of mature spermatozoa from White Pekin duck (Anas platyrhynchos): an ultrastructural and molecular analysis. Andrology 2016; 4:232-44. [DOI: 10.1111/andr.12130] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 07/30/2015] [Accepted: 10/12/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Rakesh Kumar Majhi
- School of Biological Sciences; National Institute of Science Education and Research; Bhubaneswar India
| | - Ashutosh Kumar
- School of Biological Sciences; National Institute of Science Education and Research; Bhubaneswar India
| | - Manoj Yadav
- School of Biological Sciences; National Institute of Science Education and Research; Bhubaneswar India
| | | | - Apratim Maity
- Department of Biochemistry; OVC; Orissa University of Agriculture and Technology; Bhubaneswar India
| | | | - Chandan Goswami
- School of Biological Sciences; National Institute of Science Education and Research; Bhubaneswar India
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22
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Liker A, Freckleton RP, Remeš V, Székely T. Sex differences in parental care: Gametic investment, sexual selection, and social environment. Evolution 2015; 69:2862-75. [DOI: 10.1111/evo.12786] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 09/08/2015] [Accepted: 09/17/2015] [Indexed: 11/27/2022]
Affiliation(s)
- András Liker
- Department of Animal and Plant Sciences, Alfred Denny Building; University of Sheffield; Western Bank Sheffield S10 2TN United Kingdom
- Department of Limnology; University of Pannonia; PO Box 158 8201 Veszprém Hungary
| | - Robert P. Freckleton
- Department of Animal and Plant Sciences, Alfred Denny Building; University of Sheffield; Western Bank Sheffield S10 2TN United Kingdom
| | - Vladimir Remeš
- Department of Zoology and Laboratory of Ornithology; Palacký University; 17. listopadu 50 77146 Olomouc Czech Republic
| | - Tamás Székely
- Biodiversity Laboratory, Department of Biology and Biochemistry; University of Bath; Bath BA2 7AY United Kingdom
- State Key Laboratory of Biocontrol, College of Ecology and Evolution; Sun Yat-sen University; Guangzhou 5102275 China
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23
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Abstract
Sperm competition, in which the ejaculates of multiple males compete to fertilize a female's ova, results in strong selection on sperm traits. Although sperm size and swimming velocity are known to independently affect fertilization success in certain species, exploring the relationship between sperm length, swimming velocity and fertilization success still remains a challenge. Here, we use the zebra finch (Taeniopygia guttata), where sperm size influences sperm swimming velocity, to determine the effect of sperm total length on fertilization success. Sperm competition experiments, in which pairs of males whose sperm differed only in length and swimming speed, revealed that males producing long sperm were more successful in terms of (i) the number of sperm reaching the ova and (ii) fertilizing those ova. Our results reveal that although sperm length is the main factor determining the outcome of sperm competition, complex interactions between male and female reproductive traits may also be important. The mechanisms underlying these interactions are poorly understood, but we suggest that differences in sperm storage and utilization by females may contribute to the outcome of sperm competition.
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24
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Omotoriogun TC, Albrecht T, Hořák D, Laskemoen T, Ottosson U, Rowe M, Sedláček O, Lifjeld JT. Sperm size evolution in African greenbuls (Passeriformes: Pycnonotidae). Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12663] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Taiwo C. Omotoriogun
- Natural History Museum; University of Oslo; Oslo Norway
- AP Leventis Ornithological Research Institute; University of Jos; Jos Nigeria
| | - Tomas Albrecht
- Institute of Vertebrate Biology; Academy of Sciences of the Czech Republic; Brno Czech Republic
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague Czech Republic
| | - David Hořák
- Department of Ecology; Faculty of Science; Charles University in Prague; Prague Czech Republic
| | | | - Ulf Ottosson
- AP Leventis Ornithological Research Institute; University of Jos; Jos Nigeria
| | - Melissah Rowe
- Natural History Museum; University of Oslo; Oslo Norway
- Centre for Ecological and Evolutionary Synthesis; Department of Biosciences; University of Oslo; Oslo Norway
| | - Ondřej Sedláček
- Department of Ecology; Faculty of Science; Charles University in Prague; Prague Czech Republic
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25
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Aron S, Lybaert P, Baudoux C, Vandervelden M, Fournier D. Sperm production characteristics vary with level of sperm competition in
Cataglyphis
desert ants. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12533] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Serge Aron
- Evolutionary Biology and Ecology ‐ CP 160/12 Université Libre de Bruxelles avenue Franklin D. Roosevelt 50 B ‐ 1050 Brussels Belgium
| | - Pascale Lybaert
- Hormonologie Expérimentale avenue F. D. Roosevelt 50 Université Libre de Bruxelles Brussels 1050 Belgium
| | - Claire Baudoux
- Evolutionary Biology and Ecology ‐ CP 160/12 Université Libre de Bruxelles avenue Franklin D. Roosevelt 50 B ‐ 1050 Brussels Belgium
| | - Morgane Vandervelden
- Evolutionary Biology and Ecology ‐ CP 160/12 Université Libre de Bruxelles avenue Franklin D. Roosevelt 50 B ‐ 1050 Brussels Belgium
| | - Denis Fournier
- Evolutionary Biology and Ecology ‐ CP 160/12 Université Libre de Bruxelles avenue Franklin D. Roosevelt 50 B ‐ 1050 Brussels Belgium
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26
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Cramer ERA, Laskemoen T, Stensrud E, Rowe M, Haas F, Lifjeld JT, Saetre GP, Johnsen A. Morphology-function relationships and repeatability in the sperm of Passer sparrows. J Morphol 2014; 276:370-7. [PMID: 25427840 DOI: 10.1002/jmor.20346] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 10/14/2014] [Accepted: 11/08/2014] [Indexed: 11/11/2022]
Abstract
Sperm performance is likely to be an important determinant of male reproductive success, especially when females copulate with multiple males. Understanding sperm performance is therefore crucial to fully understand the evolution of male reproductive strategies. In this study, we examined the repeatability of sperm morphology and motility measures over three breeding seasons, and we studied relationships between sperm morphology and function. We conducted this study in wild-derived captive house sparrows (Passer domesticus) and Spanish sparrows (P. hispaniolensis). Results for the two species were similar. As predicted from results in other passerine species, total sperm length was highly repeatable across ejaculates, and repeatability for the length of other components was moderate. The repeatability of sperm swimming speed across ejaculates was lower, but statistically significant, suggesting that sperm velocity may be a relatively dynamic trait. Surprisingly, swimming speed did not correlate with the relative length of the midpiece, and it correlated negatively with the relative length of the flagellum and with total sperm length. This pattern is the opposite of what theory predicts and differs from what has been found in house sparrows before. Also contrary to previous work, we found no evidence that total sperm length correlates with sperm longevity. These results therefore highlight the need for a better understanding of relationships between sperm morphology and function in passerine birds.
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Affiliation(s)
- Emily R A Cramer
- Natural History Museum, University of Oslo, Blindern, 0318, Oslo, Norway
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27
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Zajitschek S, Hotzy C, Zajitschek F, Immler S. Short-term variation in sperm competition causes sperm-mediated epigenetic effects on early offspring performance in the zebrafish. Proc Biol Sci 2014; 281:20140422. [PMID: 24789902 PMCID: PMC4024299 DOI: 10.1098/rspb.2014.0422] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/01/2014] [Indexed: 11/12/2022] Open
Abstract
The inheritance of non-genetic factors is increasingly seen to play a major role in ecology and evolution. While the causes and consequences of epigenetic effects transmitted from the mother to the offspring have received ample attention, much less is known about how variation in the condition of the father affects the offspring. Here, we manipulated the intensity of sperm competition experienced by male zebrafish Danio rerio to investigate the potential for sperm-mediated epigenetic effects over a relatively short period of time. We found that the rapid responses of males to varying intensity of sperm competition not only affected sperm traits as shown previously, but also the performance of the resulting offspring. We observed that males exposed to high intensity of sperm competition produced faster swimming and more motile sperm, and sired offspring that hatched over a narrower time frame but exhibited a lower survival rate than males exposed to low intensity of sperm competition. Our results provide striking evidence for short-term paternal effects and the possible fitness consequences of such sperm-mediated non-genetic factors not only for the resulting offspring but also for the female.
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Affiliation(s)
- Susanne Zajitschek
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
| | - Cosima Hotzy
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
| | - Felix Zajitschek
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
| | - Simone Immler
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
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28
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Testing a post-copulatory pre-zygotic reproductive barrier in a passerine species pair. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1724-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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29
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Ramm SA, Schärer L. The evolutionary ecology of testicular function: size isn't everything. Biol Rev Camb Philos Soc 2014; 89:874-88. [DOI: 10.1111/brv.12084] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 12/23/2013] [Accepted: 01/12/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Steven A. Ramm
- Evolutionary Biology; Bielefeld University; Morgenbreede 45 33615 Bielefeld Germany
| | - Lukas Schärer
- Evolutionary Biology; Zoological Institute, University of Basel; Vesalgasse 1 4051 Basel Switzerland
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30
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No experimental evidence for sneaking in a west african cichlid fish with extremely long sperm. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2014; 2013:714304. [PMID: 24386589 PMCID: PMC3872403 DOI: 10.1155/2013/714304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/10/2013] [Indexed: 11/17/2022]
Abstract
Alternative reproductive tactics are widespread in fishes, increasing the potential for sperm competition. Sperm competition has enormous impact on both variation in sperm numbers and sperm size. In cichlids, the sperm competition risk is very divergent and longer sperm are usually interpreted as adaptation to sperm competition. Here we examined whether sneaking tactics exist in Pelvicachromis taeniatus, a socially monogamous cichlid with biparental brood care from West Africa. The small testis indicates low gonadal investment which is typical for genetically monogamous species. In contrast, sperm length with up to 85 μm is extraordinarily long. We examined the reproductive behaviour of ten groups with a male-biased sex ratio under semi-natural conditions via continuous video recording. We recorded spawning site preferences and correlates of reproductive success and conducted paternity tests using microsatellites. Safe breeding sites that could be successfully defended were preferred. All offspring could be assigned to their parents and no multiple paternities were detected. Body size of spawning pairs predicted their spawning probability and offspring hatching rate suggesting benefits from mating with large individuals. Our study suggests low risk of sperm competition under the given conditions in P. taeniatus and thus first evidence for genetic monogamy in a substrate breeding cichlid.
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31
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du Plessis L, Soley JT. Light microscopic features and morphometry of sperm in the emu (Dromaius novaehollandiae). Theriogenology 2014; 81:203-9. [DOI: 10.1016/j.theriogenology.2013.08.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/16/2013] [Accepted: 08/24/2013] [Indexed: 11/24/2022]
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32
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Cramer ERA, Laskemoen T, Kleven O, LaBarbera K, Lovette IJ, Lifjeld JT. No evidence that sperm morphology predicts paternity success in wild house wrens. Behav Ecol Sociobiol 2013. [DOI: 10.1007/s00265-013-1594-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Šandera M, Albrecht T, Stopka P. Variation in apical hook length reflects the intensity of sperm competition in murine rodents. PLoS One 2013; 8:e68427. [PMID: 23844198 PMCID: PMC3700964 DOI: 10.1371/journal.pone.0068427] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 05/30/2013] [Indexed: 11/18/2022] Open
Abstract
Background Post-copulatory sexual selection has been shown to shape morphology of male gametes. Both directional and stabilizing selection on sperm phenotype have been documented in vertebrates in response to sexual promiscuity. Methodology Here we investigated the degree of variance in apical hook length and tail length in six taxa of murine rodents. Conclusions Tail sperm length and apical hook length were positively associated with relative testis mass, our proxy for levels of sperm competition, thus indicating directional post-copulatory selection on sperm phenotypes. Moreover, our study shows that increased levels of sperm competition lead to the reduction of variance in the hook length, indicating stabilizing selection. Hence, the higher risk of sperm competition affects increasing hook length together with decreasing variance in the hook length. Species-specific post-copulatory sexual selection likely optimizes sperm morphology.
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Affiliation(s)
- Martin Šandera
- Biocev group, Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Tomáš Albrecht
- Biocev group, Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Pavel Stopka
- Biocev group, Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
- * E-mail:
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34
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35
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Lifjeld JT, Hoenen A, Johannessen LE, Laskemoen T, Lopes RJ, Rodrigues P, Rowe M. The Azores bullfinch (Pyrrhula murina) has the same unusual and size-variable sperm morphology as the Eurasian bullfinch (Pyrrhula pyrrhula). Biol J Linn Soc Lond 2013. [DOI: 10.1111/j.1095-8312.2012.02040.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jan T. Lifjeld
- Natural History Museum; University of Oslo; PO Box 1172 Blindern 0318 Oslo Norway
| | - Antje Hoenen
- Electron Microscopical Unit for Biological Sciences; Department of Molecular Biosciences; University of Oslo; PO Box 1041 Blindern 0316 Oslo Norway
| | | | - Terje Laskemoen
- Natural History Museum; University of Oslo; PO Box 1172 Blindern 0318 Oslo Norway
| | - Ricardo J. Lopes
- CIBIO; Centro de Investigação em Biodiversidade e Recursos Genéticos; InBIO Laboratório Associado; Universidade do Porto; 4485-661 Vairão Portugal
| | - Pedro Rodrigues
- CIBIO; Centro de Investigação em Biodiversidade e Recursos Genéticos; InBIO Laboratório Associado; Universidade do Porto; 4485-661 Vairão Portugal
- CIBIO; Centro de Investigação em Biodiversidade e Recursos Genéticos; InBIO Laboratório Associado; Polo dos Açores; Universidade dos Açores; 9501-801 Ponta Delgada Portugal
| | - Melissah Rowe
- Natural History Museum; University of Oslo; PO Box 1172 Blindern 0318 Oslo Norway
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36
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Rowe M, Laskemoen T, Johnsen A, Lifjeld JT. Evolution of sperm structure and energetics in passerine birds. Proc Biol Sci 2013; 280:20122616. [PMID: 23282997 DOI: 10.1098/rspb.2012.2616] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Spermatozoa exhibit considerable interspecific variability in size and shape. Our understanding of the adaptive significance of this diversity, however, remains limited. Determining how variation in sperm structure translates into variation in sperm performance will contribute to our understanding of the evolutionary diversification of sperm form. Here, using data from passerine birds, we test the hypothesis that longer sperm swim faster because they have more available energy. We found that sperm with longer midpieces have higher levels of intracellular adenosine triphosphate (ATP), but that greater energy reserves do not translate into faster-swimming sperm. Additionally, we found that interspecific variation in sperm ATP concentration is not associated with the level of sperm competition faced by males. Finally, using Bayesian methods, we compared the evolutionary trajectories of sperm morphology and ATP content, and show that both traits have undergone directional evolutionary change. However, in contrast to recent suggestions in other taxa, we show that changes in ATP are unlikely to have preceded changes in morphology in passerine sperm. These results suggest that variable selective pressures are likely to have driven the evolution of sperm traits in different taxa, and highlight fundamental biological differences between taxa with internal and external fertilization, as well as those with and without sperm storage.
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Affiliation(s)
- Melissah Rowe
- Natural History Museum, University of Oslo, 0318 Oslo, Norway.
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Abstract
Females frequently mate with several males, whose sperm then compete to fertilize available ova. Sperm competition represents a potent selective force that is expected to shape male expenditure on the ejaculate. Here, we review empirical data that illustrate the evolutionary consequences of sperm competition. Sperm competition favors the evolution of increased testes size and sperm production. In some species, males appear capable of adjusting the number of sperm ejaculated, depending on the perceived levels of sperm competition. Selection is also expected to act on sperm form and function, although the evidence for this remains equivocal. Comparative studies suggest that sperm length and swimming speed may increase in response to selection from sperm competition. However, the mechanisms driving this pattern remain unclear. Evidence that sperm length influences sperm swimming speed is mixed and fertilization trials performed across a broad range of species demonstrate inconsistent relationships between sperm form and function. This ambiguity may in part reflect the important role that seminal fluid proteins (sfps) play in affecting sperm function. There is good evidence that sfps are subject to selection from sperm competition, and recent work is pointing to an ability of males to adjust their seminal fluid chemistry in response to sperm competition from rival males. We argue that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity. Research at the genomic level will identify the genes that ultimately control male fertility.
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Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, , School of Animal Biology (M092), The University of Western Australia, Crawley, Western Australia 6009, Australia.
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Immler S, Gonzalez-Voyer A, Birkhead TR. Distinct evolutionary patterns of morphometric sperm traits in passerine birds. Proc Biol Sci 2012; 279:4174-82. [PMID: 22896646 DOI: 10.1098/rspb.2012.1398] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The striking diversity of sperm shape across the animal kingdom is still poorly understood. Postcopulatory sexual selection is an important factor driving the evolution of sperm size and shape. Interestingly, morphometric sperm traits, such as the length of the head, midpiece and flagellum, exhibit a strong positive phenotypic correlation across species. Here we used recently developed comparative methods to investigate how such phenotypic correlations between morphometric sperm traits may evolve. We compare allometric relationships and evolutionary trajectories of three morphometric sperm traits (length of head, midpiece and flagellum) in passerine birds. We show that these traits exhibit strong phenotypic correlations but that allometry varies across families. In addition, the evolutionary trajectories of the midpiece and flagellum are similar while the trajectory for head length differs. We discuss our findings in the light of three scenarios accounting for correlated trait evolution: (i) genetic correlation; (ii) concerted response to selection acting simultaneously on different traits; and (iii) phenotypic correlation between traits driven by mechanistic constraints owing to selection on sperm performance. Our results suggest that concerted response to selection is the most likely explanation for the phenotypic correlation between morphometric sperm traits.
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Affiliation(s)
- Simone Immler
- Department of Animal and Plant Sciences, University of Sheffield, , Western Bank, Sheffield S10 2TN, UK.
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Female reproductive tract form drives the evolution of complex sperm morphology. Proc Natl Acad Sci U S A 2012; 109:4538-43. [PMID: 22323584 DOI: 10.1073/pnas.1111474109] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The coevolution of female mate preferences and exaggerated male traits is a fundamental prediction of many sexual selection models, but has largely defied testing due to the challenges of quantifying the sensory and cognitive bases of female preferences. We overcome this difficulty by focusing on postcopulatory sexual selection, where readily quantifiable female reproductive tract structures are capable of biasing paternity in favor of preferred sperm morphologies and thus represent a proximate mechanism of female mate choice when ejaculates from multiple males overlap within the tract. Here, we use phylogenetically controlled generalized least squares and logistic regression to test whether the evolution of female reproductive tract design might have driven the evolution of complex, multivariate sperm form in a family of aquatic beetles. The results indicate that female reproductive tracts have undergone extensive diversification in diving beetles, with remodeling of size and shape of several organs and structures being significantly associated with changes in sperm size, head shape, gains/losses of conjugation and conjugate size. Further, results of Bayesian analyses suggest that the loss of sperm conjugation is driven by elongation of the female reproductive tract. Behavioral and ultrastructural examination of sperm conjugates stored in the female tract indicates that conjugates anchor in optimal positions for fertilization. The results underscore the importance of postcopulatory sexual selection as an agent of diversification.
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Resolving variation in the reproductive tradeoff between sperm size and number. Proc Natl Acad Sci U S A 2011; 108:5325-30. [PMID: 21402912 DOI: 10.1073/pnas.1009059108] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spermatozoa are amongst the most variable cells, and three factors are thought to account for this variation in design: fertilization mode, phylogeny, and postcopulatory sexual selection. In addition, it has long been assumed that a tradeoff exists between sperm size and number, and although postcopulatory sexual selection affects both traits, empirical evidence for a tradeoff has so far been elusive. Our recent theoretical model predicts that the nature of a direct tradeoff between sperm size and number varies with sperm competition mechanism and sperm competition risk. We test these predictions using a comparative approach in two very different taxa with different sperm competition mechanisms: passerine birds (mechanism: simple raffle) and Drosophila fruit flies (sperm displacement). We show that in both groups, males increase their total ejaculate investment with increasing sperm competition risk, but whereas passerine birds allocate disproportionately to sperm number, drosophilids allocate disproportionately to sperm size. This striking difference between the two groups can be at least partly explained by sperm competition mechanisms depending on sperm size relative to the size of the female reproductive tract: in large animals (passerines), sperm numbers are advantageous in sperm competition owing to dilution inside the female tract, whereas in small animals (drosophilids), large sperm are advantageous for physical competition (sperm displacement). Our study provides two important results. First, we provide convincing evidence for the existence of a sperm size-number tradeoff. Second, we show that by considering both sperm competition mechanism and dilution, can we account for variation in sperm size between different taxa.
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Gomendio M, Tourmente M, Roldan ERS. Why mammalian lineages respond differently to sexual selection: metabolic rate constrains the evolution of sperm size. Proc Biol Sci 2011; 278:3135-41. [PMID: 21389027 DOI: 10.1098/rspb.2011.0275] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The hypothesis that sperm competition should favour increases in sperm size, because it results in faster swimming speeds, has received support from studies on many taxa, but remains contentious for mammals. We suggest that this may be because mammalian lineages respond differently to sexual selection, owing to major differences in body size, which are associated with differences in mass-specific metabolic rate. Recent evidence suggests that cellular metabolic rate also scales with body size, so that small mammals have cells that process energy and resources from the environment at a faster rate. We develop the 'metabolic rate constraint hypothesis' which proposes that low mass-specific metabolic rate among large mammals may limit their ability to respond to sexual selection by increasing sperm size, while this constraint does not exist among small mammals. Here we show that among rodents, which have high mass-specific metabolic rates, sperm size increases under sperm competition, reaching the longest sperm sizes found in eutherian mammals. By contrast, mammalian lineages with large body sizes have small sperm, and while metabolic rate (corrected for body size) influences sperm size, sperm competition levels do not. When all eutherian mammals are analysed jointly, our results suggest that as mass-specific metabolic rate increases, so does maximum sperm size. In addition, species with low mass-specific metabolic rates produce uniformly small sperm, while species with high mass-specific metabolic rates produce a wide range of sperm sizes. These findings support the hypothesis that mass-specific metabolic rates determine the budget available for sperm production: at high levels, sperm size increases in response to sexual selection, while low levels constrain the ability to respond to sexual selection by increasing sperm size. Thus, adaptive and costly traits, such as sperm size, may only evolve under sexual selection when metabolic rate does not constrain cellular budgets.
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Affiliation(s)
- Montserrat Gomendio
- Reproductive Ecology and Biology Group, Museo Nacional de Ciencias Naturales (CSIC), José Gutierrez Abascal 2, 28006 Madrid, Spain.
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Lüpold S, Wistuba J, Damm OS, Rivers JW, Birkhead TR. Sperm competition leads to functional adaptations in avian testes to maximize sperm quantity and quality. Reproduction 2011; 141:595-605. [PMID: 21307271 DOI: 10.1530/rep-10-0501] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The outcome of sperm competition (i.e. competition for fertilization between ejaculates from different males) is primarily determined by the relative number and quality of rival sperm. Therefore, the testes are under strong selection to maximize both sperm number and quality, which are likely to result in trade-offs in the process of spermatogenesis (e.g. between the rate of spermatogenesis and sperm length or sperm energetics). Comparative studies have shown positive associations between the level of sperm competition and both relative testis size and the proportion of seminiferous (sperm-producing) tissue within the testes. However, it is unknown how the seminiferous tissue itself or the process of spermatogenesis might evolve in response to sperm competition. Therefore, we quantified the different germ cell types and Sertoli cells (SC) in testes to assess the efficiency of sperm production and its associations with sperm length and mating system across 10 species of New World Blackbirds (Icteridae) that show marked variation in sperm length and sperm competition level. We found that species under strong sperm competition generate more round spermatids (RS)/spermatogonium and have SC that support a greater number of germ cells, both of which are likely to increase the maximum sperm output. However, fewer of the RS appeared to elongate to mature spermatozoa in these species, which might be the result of selection for discarding spermatids with undesirable characteristics as they develop. Our results suggest that, in addition to overall size and gross morphology, testes have also evolved functional adaptations to maximize sperm quantity and quality.
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Affiliation(s)
- Stefan Lüpold
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
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Sperm competition selects for sperm quantity and quality in the Australian Maluridae. PLoS One 2011; 6:e15720. [PMID: 21283577 PMCID: PMC3026798 DOI: 10.1371/journal.pone.0015720] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 11/26/2010] [Indexed: 11/19/2022] Open
Abstract
When ejaculates from rival males compete for fertilization, there is strong selection for sperm traits that enhance fertilization success. Sperm quantity is one such trait, and numerous studies have demonstrated a positive association between sperm competition and both testes size and the number of sperm available for copulations. Sperm competition is also thought to favor increases in sperm quality and changes in testicular morphology that lead to increased sperm production. However, in contrast to sperm quantity, these hypotheses have received considerably less empirical support and remain somewhat controversial. In a comparative study using the Australian Maluridae (fairy-wrens, emu-wrens, grasswrens), we tested whether increasing levels of sperm competition were associated with increases in both sperm quantity and quality, as well as an increase in the relative amount of seminiferous tubule tissue contained within the testes. After controlling for phylogeny, we found positive associations between sperm competition and sperm numbers, both in sperm reserves and in ejaculate samples. Additionally, as sperm competition level increased, the proportion of testicular spermatogenic tissue also increased, suggesting that sperm competition selects for greater sperm production per unit of testicular tissue. Finally, we also found that sperm competition level was positively associated with multiple sperm quality traits, including the proportion of motile sperm in ejaculates and the proportion of both viable and morphologically normal sperm in sperm reserves. These results suggest multiple ejaculate traits, as well as aspects of testicular morphology, have evolved in response to sperm competition in the Australian Maluridae. Furthermore, our findings emphasize the importance of post-copulatory sexual selection as an evolutionary force shaping macroevolutionary differences in sperm phenotype.
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Smith CC, Ryan MJ. Evolution of sperm quality but not quantity in the internally fertilized fish Xiphophorus nigrensis. J Evol Biol 2010; 23:1759-71. [PMID: 20626545 DOI: 10.1111/j.1420-9101.2010.02041.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Species with alternative reproductive strategies are characterized by discrete differences among males in suites of traits related to competition for fertilizations. Models predict sneaker males should allocate more resources to their ejaculates because they experience sperm competition more frequently and often occupy a disfavoured 'role' owing to subordinance in intramale competition and female preferences for larger males. We examined whether sperm number and quality differed between male strategies in the internally fertilized fish Xiphophorus nigrensis and explored the relationship between sperm morphology and performance. We found sneaker males had similar testes sizes compared to courting males but ejaculates with both more viable and longer lived sperm. Sneaker sperm also had longer midpieces, which was positively correlated with both velocity and longevity. Our study suggests that the evolution of sperm quantity and quality can be decoupled and that the sperm morphology is likely to play an important role in mediating sperm competition through its effects on sperm performance.
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Affiliation(s)
- C C Smith
- University of Texas at Austin, Section of Integrative Biology, Austin, TX 78712, USA.
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Parker G, Immler S, Pitnick S, Birkhead T. Sperm competition games: Sperm size (mass) and number under raffle and displacement, and the evolution of P2. J Theor Biol 2010; 264:1003-23. [DOI: 10.1016/j.jtbi.2010.03.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 03/01/2010] [Accepted: 03/01/2010] [Indexed: 11/17/2022]
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Sperm quantity and quality effects on fertilization success in a highly promiscuous passerine, the tree swallow Tachycineta bicolor. Behav Ecol Sociobiol 2010. [DOI: 10.1007/s00265-010-0962-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Immler S, Pryke SR, Birkhead TR, Griffith SC. PRONOUNCED WITHIN-INDIVIDUAL PLASTICITY IN SPERM MORPHOMETRY ACROSS SOCIAL ENVIRONMENTS. Evolution 2009; 64:1634-43. [DOI: 10.1111/j.1558-5646.2009.00924.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Stelzer G, Schmidt V, Sobiraj A, Krautwald-Junghanns ME. Spermatozoa Characteristics in Six Psittacine Species Using Light Microscopy. Reprod Domest Anim 2009; 44:894-9. [DOI: 10.1111/j.1439-0531.2008.01113.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Helfenstein F, Podevin M, Richner H. Sperm morphology, swimming velocity, and longevity in the house sparrow Passer domesticus. Behav Ecol Sociobiol 2009. [DOI: 10.1007/s00265-009-0871-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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