1
|
Rumberger C, Armstrong M, Kim M, Ponce R, Melendez J, DeBiasse M, Caplins S, Bay R. Selection Over Small and Large Spatial Scales in the Face of High Gene Flow. Mol Ecol 2025; 34:e17700. [PMID: 39968778 PMCID: PMC11874683 DOI: 10.1111/mec.17700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 01/24/2025] [Accepted: 02/10/2025] [Indexed: 02/20/2025]
Abstract
Local adaptation represents the balance of selection and gene flow. Increasingly, studies find that adaptation can occur on spatial scales much smaller than the scale of dispersal, resulting in balanced polymorphisms within populations. However, microgeographic adaptation might be facilitated or hindered by large-scale environmental heterogeneity, such as across latitude. Marine systems present a special case, as many marine species have high dispersal capacity so that dispersal 'neighbourhoods' may encompass environmental heterogeneity over both small and large spatial scales. Here, we leverage fine-scale sampling across the California range of the Pacific purple sea urchin (Strongylocentrotus purpuratus), a species with previous evidence of both local adaptation and extremely high gene flow. We find that despite the complete absence of neutral population structure, satellite-based sea surface temperature and tidal zone are associated with subtle genetic differences among populations, suggesting that balanced polymorphisms can lead to adaptation across both large (latitudinal) and small (subtidal vs. intertidal) scales. In fact, some of the same genetic variants differentiate populations at both spatial scales, potentially because both environmental parameters are related to temperature. Further, we find that genes that are expressed at a single tissue or life history stage are more divergent than expected across both latitudinal and tidal zone comparisons, suggesting that these genes have specific functions that might generate phenotypic variation important for local adaptation. Together, these results suggest that even in species with little population structure, genetic variation can be sorted across varying spatial scales, potentially resulting in local adaptation across complex environmental mosaics.
Collapse
Affiliation(s)
| | | | - Martin Kim
- University of CaliforniaDavisCaliforniaUSA
| | | | | | | | | | | |
Collapse
|
2
|
Luo H, Wang Y, Huang J, Miao B, Zhang H, Luo X, You W, Lu Y, Cai M, Ke C. Intraspecific variation and functional study of VERL polymorphism in Pacific abalone (Haliotis discus hannai Ino) and giant abalone (H. gigantea Gmelin). Int J Biol Macromol 2025; 296:139677. [PMID: 39793801 DOI: 10.1016/j.ijbiomac.2025.139677] [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] [Received: 07/06/2024] [Revised: 01/07/2025] [Accepted: 01/07/2025] [Indexed: 01/13/2025]
Abstract
Sperm and eggs have interacting proteins on their surfaces that affect their compatibility during fertilization. These gamete recognition proteins (GRPs) are typically polymorphic within species, resulting in variations in gamete affinity. This study presents the full-length sequence of VERL, an egg vitelline envelope receptor for sperm lysin, in Pacific abalone (Haliotis discus hannai Ino) and giant abalone (Haliotis gigantea Gmelin). The full-length VERL cDNA sequence in Pacific abalone (11,373 bp) encodes 3790 amino acids, most of which are organized into 21 tandem repeats. In giant abalone, the VERL spans 9405 bp and encodes 3134 amino acids, including 17 tandem repeats. By resolving the nucleotide polymorphisms from resequencing data into haplotypes, high allelic diversity was found in VERL domain repeats 1-2 in both species. Further analysis of intraspecific variation in this region revealed that the alleles of VERL repeats 1-2 in Pacific abalone clustered into two clades, yet no significant divergence was observed among the three Pacific abalone geographic populations. In contrast, alleles in giant abalone were subdivided into two distinct branches, separated by a maximum of 12 amino acid substitutions. Notably, this study provides the first evidence of assortative mating between male and female gametes based on VERL genotypes in giant abalone. Overall, this study revealed the amino acid polymorphism of VERL in two abalone species and its functional effects on fertilization potential. These findings provide a foundation for future research on gamete recognition mechanisms and support selective breeding strategies to enhance abalone reproductive efficiency.
Collapse
Affiliation(s)
- Hanjiao Luo
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Yi Wang
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Jie Huang
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Benben Miao
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Haichen Zhang
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Xuan Luo
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Weiwei You
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Ying Lu
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Mingyi Cai
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Jimei University, Xiamen, Fujian, China.
| | - Caihuan Ke
- State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
| |
Collapse
|
3
|
Tjeerdema E, Lee Y, Metry R, Hamdoun A. Semi-automated, high-content imaging of drug transporter knockout sea urchin (Lytechinus pictus) embryos. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2024; 342:313-329. [PMID: 38087422 PMCID: PMC12010930 DOI: 10.1002/jez.b.23231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 11/08/2023] [Accepted: 11/19/2023] [Indexed: 05/01/2024]
Abstract
A defining feature of sea urchins is their extreme fecundity. Urchins produce millions of transparent, synchronously developing embryos, ideal for spatial and temporal analysis of development. This biological feature has been effectively utilized for ensemble measurement of biochemical changes. However, it has been underutilized in imaging studies, where single embryo measurements are used. Here we present an example of how stable genetics and high content imaging, along with machine learning-based image analysis, can be used to exploit the fecundity and synchrony of sea urchins in imaging-based drug screens. Building upon our recently created sea urchin ABCB1 knockout line, we developed a high-throughput assay to probe the role of this drug transporter in embryos. We used high content imaging to compare accumulation and toxicity of canonical substrates and inhibitors of the transporter, including fluorescent molecules and antimitotic cancer drugs, in homozygous knockout and wildtype embryos. To measure responses from the resulting image data, we used a nested convolutional neural network, which rapidly classified embryos according to fluorescence or cell division. This approach identified sea urchin embryos with 99.8% accuracy and determined two-cell and aberrant embryos with 96.3% and 89.1% accuracy, respectively. The results revealed that ABCB1 knockout embryos accumulated the transporter substrate calcein 3.09 times faster than wildtypes. Similarly, knockouts were 4.71 and 3.07 times more sensitive to the mitotic poisons vinblastine and taxol. This study paves the way for large scale pharmacological screens in the sea urchin embryo.
Collapse
Affiliation(s)
- Evan Tjeerdema
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Yoon Lee
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Rachel Metry
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Amro Hamdoun
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| |
Collapse
|
4
|
Sherman CDH, Careau V, Gasparini C, Weston KJ, Evans JP. Population density effects on gamete traits and fertilisation dynamics under varying sperm environments in mussels. Ecol Evol 2024; 14:e11338. [PMID: 38698926 PMCID: PMC11063781 DOI: 10.1002/ece3.11338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 04/05/2024] [Accepted: 04/12/2024] [Indexed: 05/05/2024] Open
Abstract
Gamete traits can vary widely among species, populations and individuals, influencing fertilisation dynamics and overall reproductive fitness. Sexual selection can play an important role in determining the evolution of gamete traits with local environmental conditions determining the strength and direction of sexual selection. Here, we test for signatures of post-mating selection on gamete traits in relation to population density, and possible interactive effects of population density and sperm concentration on sperm motility and fertilisation rates among natural populations of mussels. Our study shows that males from high-density populations produce smaller sperm compared with males from low-density populations, but we detected no effect of population density on egg size. Our results also reveal that females from low-density populations tended to exhibit lower fertilisation rates across a range of sperm concentrations, although this became less important as sperm concentration increased. Variances in fertilisation success were higher for females than males and the effect of gamete compatibility between males and females increases as sperm concentrations increase. These results suggest that local population density can influence gamete traits and fertilisation dynamics but also highlight the importance of phenotypic plasticity in governing sperm-egg interactions in a highly dynamic selective environment.
Collapse
Affiliation(s)
- Craig D. H. Sherman
- School of Life and Environmental SciencesDeakin UniversityGeelongVictoriaAustralia
| | - Vincent Careau
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
| | | | - Kim J. Weston
- School of Life and Environmental SciencesDeakin UniversityGeelongVictoriaAustralia
| | - Jonathan P. Evans
- Centre for Evolutionary Biology, School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
| |
Collapse
|
5
|
Madsen T, Ujvari B, Bauwens D, Gruber B, Georges A, Klaassen M. Polyandry and non-random fertilisation maintain long-term genetic diversity in an isolated island population of adders (Vipera berus). Heredity (Edinb) 2023; 130:64-72. [PMID: 36474024 PMCID: PMC9905584 DOI: 10.1038/s41437-022-00578-2] [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] [Received: 03/16/2022] [Revised: 11/09/2022] [Accepted: 11/12/2022] [Indexed: 12/12/2022] Open
Abstract
Conservation genetic theory suggests that small and isolated populations should be subject to reduced genetic diversity i.e., heterozygosity and allelic diversity. Our 34 years study of an isolated island population of adders (Vipera berus) in southern Sweden challenges this notion. Despite a lack of gene flow and a yearly mean estimated reproductive adult population size of only 65 adult adders (range 12-171), the population maintains high levels of heterozygosity and allelic diversity similar to that observed in two mainland populations. Even a 14-year major "bottleneck" i.e., a reduction in adult adder numbers, encompassing at least four adder generations, did not result in any reduction in the island adders' heterozygosity and allelic diversity. Female adders are polyandrous, and fertilisation is non-random, which our empirical data and modelling suggest are underpinning the maintenance of the population's high level of heterozygosity. Our empirical results and subsequent modelling suggest that the positive genetic effects of polyandry in combination with non-random fertilisation, often overlooked in conservation genetic analyses, deserve greater consideration when predicting long-term survival of small and isolated populations.
Collapse
Affiliation(s)
- Thomas Madsen
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, 3217, Australia.
| | - Beata Ujvari
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, 3217, Australia
| | - Dirk Bauwens
- Department of Biology, Laboratory of Functional Morphology, University of Antwerp, Wilrijk, Belgium
| | - Bernd Gruber
- Institute for Applied Ecology, University of Canberra, Canberra, ACT, 2601, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, ACT, 2601, Australia
| | - Marcel Klaassen
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, 3217, Australia
| |
Collapse
|
6
|
Graziano M, Palit S, Yethiraj A, Immler S, Gage MJG, Purchase CF. Frequency-dependent viscosity of salmon ovarian fluid has biophysical implications for sperm-egg interactions. J Exp Biol 2023; 226:jeb244712. [PMID: 36511132 PMCID: PMC10086386 DOI: 10.1242/jeb.244712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 12/02/2022] [Indexed: 12/15/2022]
Abstract
Gamete-level sexual selection of externally fertilising species is usually achieved by modifying sperm behaviour with mechanisms that alter the chemical environment in which gametes perform. In fish, this can be accomplished through the ovarian fluid, a substance released with the eggs at spawning. While the biochemical effects of ovarian fluid in relation to sperm energetics have been investigated, the influence of the physical environment in which sperm compete remains poorly explored. Our objective was therefore to gain insights on the physical structure of this fluid and potential impacts on reproduction. Using soft-matter physics approaches of steady-state and oscillatory viscosity measurements, we subjected wild Atlantic salmon ovarian fluids to variable shear stresses and frequencies resembling those exerted by sperm swimming through the fluid near eggs. We show that this fluid, which in its relaxed state is a gel-like substance, displays a non-Newtonian viscoelastic and shear-thinning profile, where the viscosity decreases with increasing shear rates. We concurrently find that this fluid obeys the Cox-Merz rule below 7.6 Hz and infringes it above this level, thus indicating a shear-thickening phase where viscosity increases provided it is probed gently enough. This suggests the presence of a unique frequency-dependent structural network with relevant implications for sperm energetics and fertilisation dynamics. This article has an associated ECR Spotlight interview with Marco Graziano.
Collapse
Affiliation(s)
- Marco Graziano
- Department of Biology, Memorial University, St. John's, Newfoundland and Labrador, A1B 3X9, Canada
- Department of Biological Sciences, Centre for Ecology, Evolution, and Conservation, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Swomitra Palit
- Department of Physics and Physical Oceanography, Soft Matter Lab, Memorial University, St. John's, Newfoundland and Labrador, A1B 3X7, Canada
| | - Anand Yethiraj
- Department of Physics and Physical Oceanography, Soft Matter Lab, Memorial University, St. John's, Newfoundland and Labrador, A1B 3X7, Canada
| | - Simone Immler
- Department of Biological Sciences, Centre for Ecology, Evolution, and Conservation, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Matthew J. G. Gage
- Department of Biological Sciences, Centre for Ecology, Evolution, and Conservation, University of East Anglia, Norwich NR4 7TJ, United Kingdom
- Deceased
| | - Craig F. Purchase
- Department of Biology, Memorial University, St. John's, Newfoundland and Labrador, A1B 3X9, Canada
| |
Collapse
|
7
|
Carter R, Miller LH, Culleton R. On Malaria Transmission and Transmission Blocking Immunity. Am J Trop Med Hyg 2022; 107:tpmd211319. [PMID: 35895377 DOI: 10.4269/ajtmh.21-1319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/03/2022] [Indexed: 02/18/2024] Open
Affiliation(s)
| | - Louis H Miller
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Japan
| |
Collapse
|
8
|
Roberts EK, Tardif S, Wright EA, Platt RN, Bradley RD, Hardy DM. Rapid divergence of a gamete recognition gene promoted macroevolution of Eutheria. Genome Biol 2022; 23:155. [PMID: 35821049 PMCID: PMC9275260 DOI: 10.1186/s13059-022-02721-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 06/29/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Speciation genes contribute disproportionately to species divergence, but few examples exist, especially in vertebrates. Here we test whether Zan, which encodes the sperm acrosomal protein zonadhesin that mediates species-specific adhesion to the egg's zona pellucida, is a speciation gene in placental mammals. RESULTS Genomic ontogeny reveals that Zan arose by repurposing of a stem vertebrate gene that was lost in multiple lineages but retained in Eutheria on acquiring a function in egg recognition. A 112-species Zan sequence phylogeny, representing 17 of 19 placental Orders, resolves all species into monophyletic groups corresponding to recognized Orders and Suborders, with <5% unsupported nodes. Three other rapidly evolving germ cell genes (Adam2, Zp2, and Prm1), a paralogous somatic cell gene (TectA), and a mitochondrial gene commonly used for phylogenetic analyses (Cytb) all yield trees with poorer resolution than the Zan tree and inferior topologies relative to a widely accepted mammalian supertree. Zan divergence by intense positive selection produces dramatic species differences in the protein's properties, with ordinal divergence rates generally reflecting species richness of placental Orders consistent with expectations for a speciation gene that acts across a wide range of taxa. Furthermore, Zan's combined phylogenetic utility and divergence exceeds those of all other genes known to have evolved in Eutheria by positive selection, including the only other mammalian speciation gene, Prdm9. CONCLUSIONS Species-specific egg recognition conferred by Zan's functional divergence served as a mode of prezygotic reproductive isolation that promoted the extraordinary adaptive radiation and success of Eutheria.
Collapse
Affiliation(s)
- Emma K. Roberts
- Department of Biological Sciences, Texas Tech University, Lubbock, TX USA
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX USA
| | - Steve Tardif
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX USA
- Reproductive Biology Division, JangoBio, Fitchburg, WI USA
| | - Emily A. Wright
- Department of Biological Sciences, Texas Tech University, Lubbock, TX USA
| | - Roy N. Platt
- Host-Pathogen Interaction Program, Texas Biomedical Research Institute, San Antonio, TX USA
| | - Robert D. Bradley
- Department of Biological Sciences, Texas Tech University, Lubbock, TX USA
- Natural Science Research Laboratory, Museum of Texas Tech University, Lubbock, TX USA
| | - Daniel M. Hardy
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX USA
| |
Collapse
|
9
|
Ocean Acidification, but Not Environmental Contaminants, Affects Fertilization Success and Sperm Motility in the Sea Urchin Paracentrotus lividus. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10020247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ocean acidification poses an increasing concern for broadcast spawning species that release gametes in the water column where fertilization occurs. Indeed, the functionality of gametes and their interactions may be negatively affected by reduced pH. Susceptibility to other environmental stressors, such as pollutants, may be also altered under acidified conditions, resulting in more detrimental effects. To verify this hypothesis, combined exposures to CO2-driven acidification and environmentally relevant concentrations (0.5 µg/L) of three contaminants (caffeine, diclofenac, and PFOS, all singularly or in mixture) were carried out to highlight potential negative effects on fertilization success and motility of sperm in the sea urchin Paracentrotus lividus. Our results showed a significant reduction in the percentage of fertilized eggs when sperm were pre-exposed to reduced pH (ambient pH minus 0.4 units) compared to that of controls (ambient, pH = 8.1). Sperm speed and motility also decreased when sperm were activated and then exposed at reduced pH. Conversely, at both pH values tested, no significant effect due to the contaminants, nor of their interaction with pH, was found on any of the biological endpoints considered.
Collapse
|
10
|
Svensson EI, Blaimont P, Calsbeek R, Lancaster LT, McAdam A, Mills SC. In Memoriam: Barry Sinervo 1961-2021. Evolution 2021. [PMID: 34881444 DOI: 10.1111/evo.14416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Erik I Svensson
- Evolutionary Ecology Unit, Department of Biology, Lund University, Lund, SE-223 62, Sweden
| | - Pauline Blaimont
- Department of Biology, Behavioral Neuroscience and Health Sciences, Rider University, Lawrenceville, New Jersey, 08648
| | - Ryan Calsbeek
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, 03755
| | - Lesley T Lancaster
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - Andrew McAdam
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, 80309
| | - Suzanne C Mills
- PSL Université Paris, EPHE-UPVD-CNRS, USR 3278 CRIOBE, 98729 Papetoai, Moorea, French Polynesia.,Laboratoire d'Excellence, CORAIL, 58 avenue Paul Alduy, CEDEX, 668 60, France
| |
Collapse
|
11
|
Guerra VI, Haynes G, Byrne M, Hart MW. Selection on genes associated with the evolution of divergent life histories: Gamete recognition or something else? Evol Dev 2021; 23:423-438. [PMID: 34549504 DOI: 10.1111/ede.12392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 04/17/2021] [Accepted: 06/02/2021] [Indexed: 12/13/2022]
Abstract
Gamete compatibility, and fertilization success, is mediated by gamete-recognition genes (GRGs) that are expected to show genetic evidence of a response to sexual selection associated with mating system traits. Changes in the strength of sexual selection can arise from the resolution of sperm competition among males, sexual conflicts of interest between males and females, or other mechanisms of sexual selection. To assess these expectations, we compared patterns of episodic diversifying selection among genes expressed in the gonads of Cryptasterina pentagona and C. hystera, which recently speciated and have evolved different mating systems (gonochoric or hermaphroditic), modes of fertilization (outcrossing or selfing), and dispersal (planktonic larvae or internal brooding). Cryptasterina spp. inhabit the upper intertidal of the coast of Queensland and coral islands of the Great Barrier Reef. We found some evidence for positive selection on a GRG in the outcrossing C. pentagona, and we found evidence of loss of gene function in a GRG of the self-fertilizing C. hystera. The modification or loss of gene functionality may be evidence of relaxed selection on some aspects of gamete interaction in C. hystera. In addition to these genes involved in gamete interactions, we also found genes under selection linked to abiotic stress, chromosomal regulation, polyspermy, and egg-laying. We interpret those results as possible evidence that Cryptasterina spp. with different mating systems may have been adapting in divergent ways to oxidative stress or other factors associated with reproduction in the physiologically challenging environment of the high intertidal. RESEARCH HIGHLIGHTS: Recent speciation between two sea stars was unlikely the result of selection on gamete-recognition genes annotated in this study. Instead, our results point to selection on genes linked to the intertidal environment and reproduction.
Collapse
Affiliation(s)
- Vanessa I Guerra
- Department of Biological Sciences and Crawford Laboratory of Evolutionary Studies, Simon Fraser University, Burnaby, British Columbia, Canada.,Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, USA
| | - Gwilym Haynes
- Department of Biological Sciences and Crawford Laboratory of Evolutionary Studies, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Maria Byrne
- School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Michael W Hart
- Department of Biological Sciences and Crawford Laboratory of Evolutionary Studies, Simon Fraser University, Burnaby, British Columbia, Canada
| |
Collapse
|
12
|
Magris M, Jokiniemi A, Kuusipalo L, Ritari J, Koskela S, Partanen J, Kekäläinen J. Structural dissimilarity of partners' immune genes increases sperm viability in women's reproductive tract. J Evol Biol 2021; 34:1125-1132. [PMID: 34056789 DOI: 10.1111/jeb.13872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/04/2021] [Accepted: 05/07/2021] [Indexed: 01/17/2023]
Abstract
Human leucocyte antigen (HLA) genes appear to mediate pre- and post-copulatory mate choice towards HLA-dissimilar ('compatible') partners. However, since genetically distinct alleles often have similar immunogenic properties, genetic dissimilarity is not necessarily an accurate predictor of the functional compatibility of HLA alleles and, hence, may not reflect partners' true compatibility. Furthermore, it has remained unclear whether other genes of the immune system could also play a role in male-female compatibility. We studied whether the immunoglobulin binding regions (eplets) of HLA molecules and the immunoglobulin structural dissimilarity of the partners affect their gamete-level compatibility. We exposed sperm of multiple men to follicular fluid or cervical mucus of multiple women and tested whether sperm viability in these reproductive secretions was influenced by HLA eplet and immunoglobulin structural dissimilarity between partners. We found that eplet dissimilarity positively affects sperm viability in follicular fluid, whereas immunoglobulin dissimilarity enhanced sperm viability in cervical mucus. Together, these findings indicate that structural characteristics of both HLA alleles and immunoglobulins may facilitate cryptic female choice towards immunologically compatible partners. Our results, thus, indicate that partners' genetic compatibility may have wider immunological basis than traditionally has been assumed. Relative contribution of different immunogenetic factors to overall compatibility of the reproductive partners needs to be clarified in future studies.
Collapse
Affiliation(s)
- Martina Magris
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Annalaura Jokiniemi
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | | | - Jarmo Ritari
- Finnish Red Cross Blood Service, Research and Development, Helsinki, Finland
| | - Satu Koskela
- Finnish Red Cross Blood Service, Research and Development, Helsinki, Finland
| | - Jukka Partanen
- Finnish Red Cross Blood Service, Research and Development, Helsinki, Finland
| | - Jukka Kekäläinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| |
Collapse
|
13
|
Yasui Y, Yamamoto Y. An empirical test of bet-hedging polyandry hypothesis in the field cricket Gryllus bimaculatus. J ETHOL 2021. [DOI: 10.1007/s10164-021-00707-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractTheory shows that polyandry (mating with multiple males within a reproductive season) works as bet-hedging to increase the geometric mean fitness (GMF) of polyandrous genotype over generations and avoid extinction but it was rarely tested empirically. In this study, we distributed the eggs of Gryllus bimaculatus females mated with 1–4 males (mating treatment) into 4 petri dishes with different conditions: 25 °C/fresh water, 37 °C/fresh water, 25 °C/salt water, 37 °C/salt water, simulating 4 clutches laid at the different sites are suffered environmental change. The egg hatching rate was obtained over 7 blocks with different females for each mating treatment. In general, significantly more eggs hatched in 25 °C than 37 °C and in fresh water than salt water. The reproductive failure (no hatched eggs per petri dish) frequently occurred in monandry and 2-male polyandry. Next, we considered 7 blocks as the successive 7 virtual generations and calculated the within-generation arithmetic mean fitness (AMF) among females of the same treatment and the between-generation GMF of the AMF across 7 generations. Randomization test shows that the GMF of 3- and 4-male polyandry were significantly higher than monandry. This study shows that the risk from mating only once can be avoided by polyandrous mating as bet-hedging.
Collapse
|
14
|
Byrne PG, Keogh JS, O'Brien DM, Gaitan-Espitia JD, Silla AJ. Evidence that genetic compatibility underpins female mate choice in a monandrous amphibian. Evolution 2021; 75:529-541. [PMID: 33389749 DOI: 10.1111/evo.14160] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/03/2020] [Accepted: 12/16/2020] [Indexed: 12/24/2022]
Abstract
Mate choice for genetic benefits remains controversial, largely because few studies have estimated the relative contributions of additive and non-additive sources of genetic variation to offspring fitness. Moreover, there remains a deficit of these estimates for species where female-mate preferences have been quantified in the wild, especially species characterized by monandry or monogamy. Here, we use artificial fertilization techniques combined with a cross-classified breeding design to simultaneously test for "good genes" and "compatible genes" benefits of mate choice in the monandrous red backed toadlet (Pseudophryne coriacea). In addition, we used a genomic approach to estimate effects of parental-genetic relatedness (assessed using 27, 768 single nucleotide polymorphisms) on offspring fitness. Our results revealed no significant additive genetic effects (sire effects), but highly significant non-additive genetic effects (sire × dam interaction effects), on fertilization success, survival during embryonic development, and hatching success. We also found significant associations between parental genetic similarity and offspring survival (whereby survival was higher when parents were more related), and significant positive relationships between fertilization success and embryo survival through to hatching. These results indicate that offspring viability is significantly influenced by the genetic compatibility of parental genotypes, that more related parents are more genetically compatible, and that gametes with greater compatibility at fertilization produce more viable offspring. More broadly, our findings provide new quantitative genetic evidence that genetic incompatibility underpins female mate preferences. Continued quantitative genetic assessment of the relative importance of good genes versus compatible genes is needed to ascertain the general importance of genetic benefits as a driver of female mate choice.
Collapse
Affiliation(s)
- Phillip G Byrne
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - J Scott Keogh
- Ecology & Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Daniel M O'Brien
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Juan Diego Gaitan-Espitia
- The Swire Institute of Marine Science, School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Aimee J Silla
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| |
Collapse
|
15
|
Hue T, Chateau O, Lecellier G, Kayal M, Lanos N, Gossuin H, Adjeroud M, Dumas P. Temperature affects the reproductive outputs of coral-eating starfish Acanthaster spp. after adult exposure to near-future ocean warming and acidification. MARINE ENVIRONMENTAL RESEARCH 2020; 162:105164. [PMID: 33099079 DOI: 10.1016/j.marenvres.2020.105164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
Outbreaks of the coral-eating crown-of-thorns starfish Acanthaster spp. (COTS) have become to be amongst the most severe threats to coral reefs worldwide. Although most research has focused on COTS early development, it remains unclear how COTS populations will keep pace with changing ocean conditions. Since reproduction is a key process contributing to outbreaks, we investigated the reproductive success of adult COTS acclimated for 3-4 months to different treatment combinations of ambient conditions, ocean warming (+2 °C) and acidification (-0.35 pH). Our results suggest that the optimal breeding season in New Caledonia is concentrated around the end of the calendar year, when water temperature reaches >26 °C. We found negative effects of temperature on egg metrics, fertilisation success, and GSI, conflicting with previously documented effects of temperature on echinoderm reproductive outputs. Fertilisation success dropped drastically (more than threefold) with elevated temperature during the late breeding season. In contrast, we detected no effects of near-future acidification conditions on fertilisation success nor GSI. This is the first time that COTS reproduction is compared among individuals acclimated to different conditions of warming and acidification. Our results highlight the importance of accounting for adult exposure to better understand how COTS reproduction may be impacted in the face of global change.
Collapse
Affiliation(s)
- Thomas Hue
- IRD, UMR 9220 ENTROPIE, BP A5, Noumea, New Caledonia; Laboratoire d'Excellence "Corail", 58 avenue Paul Alduy, 66860, Perpignan, France.
| | - Olivier Chateau
- Laboratory of Marine Biology and Ecology, Aquarium des lagons, 98807, Noumea, New Caledonia
| | - Gael Lecellier
- IRD, UMR 9220 ENTROPIE, BP A5, Noumea, New Caledonia; Laboratoire d'Excellence "Corail", 58 avenue Paul Alduy, 66860, Perpignan, France; Université de Paris-Saclay, UVSQ, 45 avenue des Etats-Unis, Versailles Cedex, France
| | - Mohsen Kayal
- IRD, UMR 9220 ENTROPIE, BP A5, Noumea, New Caledonia; Laboratoire d'Excellence "Corail", 58 avenue Paul Alduy, 66860, Perpignan, France
| | - Noeline Lanos
- Laboratory of Marine Biology and Ecology, Aquarium des lagons, 98807, Noumea, New Caledonia
| | - Hugues Gossuin
- Laboratory of Marine Biology and Ecology, Aquarium des lagons, 98807, Noumea, New Caledonia
| | - Mehdi Adjeroud
- Laboratoire d'Excellence "Corail", 58 avenue Paul Alduy, 66860, Perpignan, France; UMR 9220 ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de la Nouvelle-Calédonie, Perpignan, France; PSL Université Paris, USR 3278 CRIOBE, EPHE-UPVD-CNRS, Perpignan, France
| | - Pascal Dumas
- IRD, UMR 9220 ENTROPIE, BP A5, Noumea, New Caledonia; Laboratoire d'Excellence "Corail", 58 avenue Paul Alduy, 66860, Perpignan, France
| |
Collapse
|
16
|
Evans JP, Lymbery RA. Sexual selection after gamete release in broadcast spawning invertebrates. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200069. [PMID: 33070722 DOI: 10.1098/rstb.2020.0069] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Broadcast spawning invertebrates offer highly tractable models for evaluating sperm competition, gamete-level mate choice and sexual conflict. By displaying the ancestral mating strategy of external fertilization, where sexual selection is constrained to act after gamete release, broadcast spawners also offer potential evolutionary insights into the cascade of events that led to sexual reproduction in more 'derived' groups (including humans). Moreover, the dynamic reproductive conditions faced by these animals mean that the strength and direction of sexual selection on both males and females can vary considerably. These attributes make broadcast spawning invertebrate systems uniquely suited to testing, extending, and sometimes challenging classic and contemporary ideas in sperm competition, many of which were first captured in Parker's seminal papers on the topic. Here, we provide a synthesis outlining progress in these fields, and highlight the burgeoning potential for broadcast spawners to provide both evolutionary and mechanistic understanding into gamete-level sexual selection more broadly across the animal kingdom. This article is part of the theme issue 'Fifty years of sperm competition'.
Collapse
Affiliation(s)
- Jonathan P Evans
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia
| | - Rowan A Lymbery
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia
| |
Collapse
|
17
|
Rowe M, Whittington E, Borziak K, Ravinet M, Eroukhmanoff F, Sætre GP, Dorus S. Molecular Diversification of the Seminal Fluid Proteome in a Recently Diverged Passerine Species Pair. Mol Biol Evol 2020; 37:488-506. [PMID: 31665510 PMCID: PMC6993853 DOI: 10.1093/molbev/msz235] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Seminal fluid proteins (SFPs) mediate an array of postmating reproductive processes that influence fertilization and fertility. As such, it is widely held that SFPs may contribute to postmating, prezygotic reproductive barriers between closely related taxa. We investigated seminal fluid (SF) diversification in a recently diverged passerine species pair (Passer domesticus and Passer hispaniolensis) using a combination of proteomic and comparative evolutionary genomic approaches. First, we characterized and compared the SF proteome of the two species, revealing consistencies with known aspects of SFP biology and function in other taxa, including the presence and diversification of proteins involved in immunity and sperm maturation. Second, using whole-genome resequencing data, we assessed patterns of genomic differentiation between house and Spanish sparrows. These analyses detected divergent selection on immunity-related SF genes and positive selective sweeps in regions containing a number of SF genes that also exhibited protein abundance diversification between species. Finally, we analyzed the molecular evolution of SFPs across 11 passerine species and found a significantly higher rate of positive selection in SFPs compared with the rest of the genome, as well as significant enrichments for functional pathways related to immunity in the set of positively selected SF genes. Our results suggest that selection on immunity pathways is an important determinant of passerine SF composition and evolution. Assessing the role of immunity genes in speciation in other recently diverged taxa should be prioritized given the potential role for immunity-related proteins in reproductive incompatibilities in Passer sparrows.
Collapse
Affiliation(s)
- Melissah Rowe
- Natural History Museum, University of Oslo, Oslo, Norway.,Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway.,Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Emma Whittington
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY
| | - Kirill Borziak
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY
| | - Mark Ravinet
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Fabrice Eroukhmanoff
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Glenn-Peter Sætre
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Steve Dorus
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY
| |
Collapse
|
18
|
Geyer LB, Zigler KS, Tiozzo S, Lessios HA. Slow evolution under purifying selection in the gamete recognition protein bindin of the sea urchin Diadema. Sci Rep 2020; 10:9834. [PMID: 32555217 PMCID: PMC7299941 DOI: 10.1038/s41598-020-66390-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/06/2020] [Indexed: 01/22/2023] Open
Abstract
Bindin is a sperm protein that mediates attachment and membrane fusion of gametes. The mode of bindin evolution varies across sea urchin genera studied to date. In three genera it evolves under positive selection, in four under mostly purifying selection, and in one, results have been mixed. We studied bindin evolution in the pantropical sea urchin Diadema, which split from other studied genera 250 million years ago. We found that Diadema bindin is structurally similar to that of other genera, but much longer (418 amino acids). In seven species of Diadema, bindin evolves under purifying selection, more slowly than in any other sea urchin genus. Only bindin of the recently rediscovered D. clarki shows evidence of positive selection. As D. clarki is sympatric with D. setosum and D. savignyi, positive selection could arise from avoidance of maladaptive hybridization. However, D. setosum and D. savignyi overlap in the Indo-West Pacific, yet their bindins show no evidence of positive selection, possibly because the two species spawn at different times. Bindin in the East Pacific D. mexicanum, the West Atlantic D. antillarum, the East Atlantic D. africanum, and the Indo-Pacific D. paucispinum also evolves slowly under purifying selection.
Collapse
Affiliation(s)
- L B Geyer
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Panama.
| | - K S Zigler
- Department of Biology, Sewanee: University of the South, 735 University Ave., Sewanee, TN, 37383, United States
| | - S Tiozzo
- Sorbonne Universite, CNRS, Laboratoire de Biologie du Developpement de Villefranche-sur-mer (LBDV), 06230, Paris, France
| | - H A Lessios
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Panama
| |
Collapse
|
19
|
Olsen KC, Ryan WH, Winn AA, Kosman ET, Moscoso JA, Krueger-Hadfield SA, Burgess SC, Carlon DB, Grosberg RK, Kalisz S, Levitan DR. Inbreeding shapes the evolution of marine invertebrates. Evolution 2020; 74:871-882. [PMID: 32191349 PMCID: PMC7383701 DOI: 10.1111/evo.13951] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 02/06/2020] [Accepted: 02/21/2020] [Indexed: 12/22/2022]
Abstract
Inbreeding is a potent evolutionary force shaping the distribution of genetic variation within and among populations of plants and animals. Yet, our understanding of the forces shaping the expression and evolution of nonrandom mating in general, and inbreeding in particular, remains remarkably incomplete. Most research on plant mating systems focuses on self-fertilization and its consequences for automatic selection, inbreeding depression, purging, and reproductive assurance, whereas studies of animal mating systems have often assumed that inbreeding is rare, and that natural selection favors traits that promote outbreeding. Given that many sessile and sedentary marine invertebrates and marine macroalgae share key life history features with seed plants (e.g., low mobility, modular construction, and the release of gametes into the environment), their mating systems may be similar. Here, we show that published estimates of inbreeding coefficients (FIS ) for sessile and sedentary marine organisms are similar and at least as high as noted in terrestrial seed plants. We also found that variation in FIS within invertebrates is related to the potential to self-fertilize, disperse, and choose mates. The similarity of FIS for these organismal groups suggests that inbreeding could play a larger role in the evolution of sessile and sedentary marine organisms than is currently recognized. Specifically, associations between traits of marine invertebrates and FIS suggest that inbreeding could drive evolutionary transitions between hermaphroditism and separate sexes, direct development and multiphasic life cycles, and external and internal fertilization.
Collapse
Affiliation(s)
- Kevin C Olsen
- Department of Biological Science, Florida State University, Tallahassee, Florida, 32304
| | - Will H Ryan
- Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Alice A Winn
- Department of Biological Science, Florida State University, Tallahassee, Florida, 32304
| | - Ellen T Kosman
- Department of Biological Science, Florida State University, Tallahassee, Florida, 32304
| | - Jose A Moscoso
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794
| | | | - Scott C Burgess
- Department of Biological Science, Florida State University, Tallahassee, Florida, 32304
| | - David B Carlon
- The Biology Department, Bowdoin College, Brunswick, Maine, 04011.,Schiller Coastal Studies Center, Bowdoin College, Orr's Island, Maine, 04066
| | - Richard K Grosberg
- Coastal and Marine Sciences Institute, University of California Davis, Davis, California, 95616
| | - Susan Kalisz
- Department of Ecology and Evolutionary Biology, University of Tennessee Knoxville, Knoxville, Tennessee, 37996
| | - Don R Levitan
- Department of Biological Science, Florida State University, Tallahassee, Florida, 32304
| |
Collapse
|
20
|
Abstract
The perpetuation and preservation of distinct species rely on mechanisms that ensure that only interactions between gametes of the same species can give rise to viable and fertile offspring. Species-specificity can act at various stages, ranging from physical/behavioral pre-copulatory mechanisms, to pre-zygotic incompatibility during fertilization, to post-zygotic hybrid incompatibility. Herein, we focus on our current knowledge of the molecular mechanisms responsible for species-specificity during fertilization. While still poorly understood, decades of research have led to the discovery of molecules implicated in species-specific gamete interactions, starting from initial sperm-egg attraction to the binding of sperm and egg. While many of these molecules have been described as species-specific in their mode of action, relatively few have been demonstrated as such with definitive evidence. Thus, we also raise remaining questions that need to be addressed in order to characterize gamete interaction molecules as species-specific.
Collapse
|
21
|
Lindsay WR, Andersson S, Bererhi B, Höglund J, Johnsen A, Kvarnemo C, Leder EH, Lifjeld JT, Ninnes CE, Olsson M, Parker GA, Pizzari T, Qvarnström A, Safran RJ, Svensson O, Edwards SV. Endless forms of sexual selection. PeerJ 2019; 7:e7988. [PMID: 31720113 PMCID: PMC6839514 DOI: 10.7717/peerj.7988] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 10/04/2019] [Indexed: 12/11/2022] Open
Abstract
In recent years, the field of sexual selection has exploded, with advances in theoretical and empirical research complementing each other in exciting ways. This perspective piece is the product of a "stock-taking" workshop on sexual selection and sexual conflict. Our aim is to identify and deliberate on outstanding questions and to stimulate discussion rather than provide a comprehensive overview of the entire field. These questions are organized into four thematic sections we deem essential to the field. First we focus on the evolution of mate choice and mating systems. Variation in mate quality can generate both competition and choice in the opposite sex, with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems, especially with regard to polyandry. Second, we focus on how sender and receiver mechanisms shape signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are challenging to measure. We view the neuroethology of sensory and cognitive receiver biases as the main key to signal form and the 'aesthetic sense' proposed by Darwin. Since a receiver bias is sufficient to both initiate and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate 'null model' of sexual selection. Thirdly, we focus on the genetic architecture of sexually selected traits. Despite advances in modern molecular techniques, the number and identity of genes underlying performance, display and secondary sexual traits remains largely unknown. In-depth investigations into the genetic basis of sexual dimorphism in the context of long-term field studies will reveal constraints and trajectories of sexually selected trait evolution. Finally, we focus on sexual selection and conflict as drivers of speciation. Population divergence and speciation are often influenced by an interplay between sexual and natural selection. The extent to which sexual selection promotes or counteracts population divergence may vary depending on the genetic architecture of traits as well as the covariance between mating competition and local adaptation. Additionally, post-copulatory processes, such as selection against heterospecific sperm, may influence the importance of sexual selection in speciation. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection, and we offer potential avenues of research to advance this progress.
Collapse
Affiliation(s)
- Willow R. Lindsay
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Staffan Andersson
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Badreddine Bererhi
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Jacob Höglund
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Arild Johnsen
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Erica H. Leder
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Jan T. Lifjeld
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Calum E. Ninnes
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, United States of America
| | - Mats Olsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Geoff A. Parker
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Tommaso Pizzari
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, United Kingdom
| | - Anna Qvarnström
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Rebecca J. Safran
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, United States of America
| | - Ola Svensson
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Huddinge, Sweden
| | - Scott V. Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States of America
- Gothenburg Centre for Advanced Studies in Science and Technology, Chalmers University of Technology, Göteborg, Sweden
| |
Collapse
|
22
|
Marks RA, Smith JJ, Cronk Q, Grassa CJ, McLetchie DN. Genome of the tropical plant Marchantia inflexa: implications for sex chromosome evolution and dehydration tolerance. Sci Rep 2019; 9:8722. [PMID: 31217536 PMCID: PMC6584576 DOI: 10.1038/s41598-019-45039-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 05/29/2019] [Indexed: 01/29/2023] Open
Abstract
We present a draft genome assembly for the tropical liverwort, Marchantia inflexa, which adds to a growing body of genomic resources for bryophytes and provides an important perspective on the evolution and diversification of land plants. We specifically address questions related to sex chromosome evolution, sexual dimorphisms, and the genomic underpinnings of dehydration tolerance. This assembly leveraged the recently published genome of related liverwort, M. polymorpha, to improve scaffolding and annotation, aid in the identification of sex-linked sequences, and quantify patterns of sequence differentiation within Marchantia. We find that genes on sex chromosomes are under greater diversifying selection than autosomal and organellar genes. Interestingly, this is driven primarily by divergence of male-specific genes, while divergence of other sex-linked genes is similar to autosomal genes. Through analysis of sex-specific read coverage, we identify and validate genetic sex markers for M. inflexa, which will enable diagnosis of sex for non-reproductive individuals. To investigate dehydration tolerance, we capitalized on a difference between genetic lines, which allowed us to identify multiple dehydration associated genes two of which were sex-linked, suggesting that dehydration tolerance may be impacted by sex-specific genes.
Collapse
Affiliation(s)
- Rose A Marks
- Department of Biology, University of Kentucky, 101 Thomas Hunt Morgan Building, Lexington, KY, 40506, USA.
| | - Jeramiah J Smith
- Department of Biology, University of Kentucky, 101 Thomas Hunt Morgan Building, Lexington, KY, 40506, USA
| | - Quentin Cronk
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
| | - Christopher J Grassa
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
- Department of Organismic and Evolutionary Biology, Harvard University Herbaria, 22 Divinity Avenue, Cambridge, MA, 02138, USA
| | - D Nicholas McLetchie
- Department of Biology, University of Kentucky, 101 Thomas Hunt Morgan Building, Lexington, KY, 40506, USA
| |
Collapse
|
23
|
Levitan DR, Buchwalter R, Hao Y. The evolution of gametic compatibility and compatibility groups in the sea urchin
Mesocentrotus franciscanus
: An avenue for speciation in the sea. Evolution 2019; 73:1428-1442. [DOI: 10.1111/evo.13766] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/02/2019] [Accepted: 05/11/2019] [Indexed: 01/17/2023]
Affiliation(s)
- Don R. Levitan
- Department of Biological Science Florida State University Tallahassee Florida 32306
| | - Rebecca Buchwalter
- Department of Biological Science Florida State University Tallahassee Florida 32306
| | - Yueling Hao
- Department of Biological Science Florida State University Tallahassee Florida 32306
| |
Collapse
|
24
|
Chan WY, Peplow LM, van Oppen MJH. Interspecific gamete compatibility and hybrid larval fitness in reef-building corals: Implications for coral reef restoration. Sci Rep 2019; 9:4757. [PMID: 30894593 PMCID: PMC6426996 DOI: 10.1038/s41598-019-41190-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/28/2019] [Indexed: 11/27/2022] Open
Abstract
Climate warming is a major cause of the global decline of coral reefs. Active reef restoration, although still in its infancy, is one of several possible ways to help restore coral cover and reef ecosystem function. The deployment of mature coral larvae onto depauperate reef substratum has been shown to significantly increase larval recruitment, providing a novel option for the delivery of ex situ bred coral stock to the reef for restoration purposes. The success of such reef restoration approaches may be improved by the use of coral larval stock augmented for climate resilience. Here we explore whether coral climate resilience can be enhanced via interspecific hybridization through hybrid vigour. Firstly, we assessed cross-fertility of four pairs of Acropora species from the Great Barrier Reef. Temporal isolation in gamete release between the Acropora species was limited, but gametic incompatibility was present with varying strength between species pairs and depending on the direction of the hybrid crosses. We subsequently examined the fitness of hybrid and purebred larvae under heat stress by comparing their survival and settlement success throughout 10 days of exposure to 28 °C, 29.5 °C and 31 °C. Fitness of the majority of Acropora hybrid larvae was similar to that of the purebred larvae of both parental species, and in some instances it was higher than that of the purebred larvae of one of the parental species. Lower hybrid fertilization success did not affect larval fitness. These findings indicate that high hybrid fitness can be achieved after overcoming partial prezygotic barriers, and that interspecific hybridization may be a tool to enhance coral recruitment and climate resilience.
Collapse
Affiliation(s)
- Wing Yan Chan
- Australian Institute of Marine Science, Townsville MC, QLD, 4810, Australia.
- School of BioSciences, University of Melbourne, VIC, 3010, Australia.
| | - Lesa M Peplow
- Australian Institute of Marine Science, Townsville MC, QLD, 4810, Australia
| | - Madeleine J H van Oppen
- Australian Institute of Marine Science, Townsville MC, QLD, 4810, Australia
- School of BioSciences, University of Melbourne, VIC, 3010, Australia
| |
Collapse
|
25
|
Kleppe SA, Nordeide JT, Rudolfsen G, Figenschou L, Larsen B, Reiss K, Folstad I. No support for cryptic choice by ovarian fluid in an external fertilizer. Ecol Evol 2018; 8:11763-11774. [PMID: 30598774 PMCID: PMC6303707 DOI: 10.1002/ece3.4628] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 09/17/2018] [Accepted: 09/19/2018] [Indexed: 12/01/2022] Open
Abstract
Whether the ovarian fluid (OF) represents a selective environment influencing cryptic female choice was tested using an external fertilizer experiencing intense sperm competition and large effects of OF on sperm swimming behavior-the Arctic charr (Salvelinus alpinus). We physically separated the OF from the eggs of reproductively active females and reintroduced either their own OF or fluid from another female to the eggs. The eggs were then fertilized in vitro in a replicated split-brood design with sperm from two males under synchronized sperm competition trials, while also measuring sperm velocity of the individual males in the individual OFs. We found large effects of males, but no effect of females (i.e., eggs) on paternity, determined from microsatellites. More important, we found no effect of OF treatments on the relative paternity of the two competing males in each pair. This experimental setup does not provide support for the hypothesis that OF plays an important role as medium for cryptic female choice in charr. Power analyses revealed that our sample size is large enough to detect medium-sized changes in relative paternity (medium-sized effect sizes), but not large enough to detect small changes in relative paternity. More studies are needed before a conclusion can be drawn about OF's potential influence on paternity under sperm competition-even in charr.
Collapse
Affiliation(s)
| | | | - Geir Rudolfsen
- Faculty of Bioscience, Fishery and EconomyUiT The Arctic University of NorwayTromsøNorway
| | - Lars Figenschou
- University Library, UiT The Arctic University of NorwayTromsøNorway
| | | | - Katrin Reiss
- Faculty of Biosciences and AquacultureNord UniversityBodøNorway
| | - Ivar Folstad
- Faculty of Bioscience, Fishery and EconomyUiT The Arctic University of NorwayTromsøNorway
| |
Collapse
|
26
|
Betters M, Levitan DR. The Role of Male Variation in Fertilization Success in Determining the Costs and Benefits of Polyandry in the Broadcast Spawning Urchin Lytechinus variegatus. THE BIOLOGICAL BULLETIN 2018; 235:63-70. [PMID: 30358447 DOI: 10.1086/699406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Although the benefits to males mating with multiple females have been well documented, the benefits to females mating with multiple males (polyandry) are less studied, particularly the mechanism that might drive these potential benefits. Benefits of polyandry might stem from increasing the chance of mating with a high-quality or compatible male or stem from the ability of multiple males to fertilize more eggs than any single male. We examine the fertilization consequences of polyandry in the sea urchin Lytechinus variegatus. This species has variation in spine color, and we conducted matings between individual and pooled sperm from two males that matched or mismatched in color. The results indicate that (1) males with white spines achieved higher fertilization and were more likely to cause polyspermy than males with purple spines, and there was no effect of female spine color on fertilization; (2) when comparing the average success of individual matings with pooled-sperm matings, there was a net benefit to polyandry when purple-spine males were pooled, a net cost when white-spine males were pooled, and no difference when mismatched spine color males were pooled; and (3) the success under pooled-sperm trials, with any of the spine color combinations, never exceeded the success of the more successful male in the individual-male trials. Together these results suggest that the consequences of polyandry depend on the relation between sperm availability and the sensitivity of eggs to sperm limitation and polyspermy with respect to the specific set of available males. The potential fertilization consequences of a female spawning with multiple males might be associated primarily with increasing the amount of sperm available to fertilize her eggs and secondarily with increasing the chances of mating with a higher-quality or more compatible male, as opposed to a diversity of males.
Collapse
|
27
|
Giesen A, Schäfer MA, Blanckenhorn WU. Geographic patterns of postzygotic isolation between two closely related widespread dung fly species (Sepsis cynipseaandSepsis neocynipsea; Diptera: Sepsidae). J ZOOL SYST EVOL RES 2018. [DOI: 10.1111/jzs.12239] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Athene Giesen
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Martin A. Schäfer
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Wolf U. Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| |
Collapse
|
28
|
Kekäläinen J, Evans JP. Gamete-mediated mate choice: towards a more inclusive view of sexual selection. Proc Biol Sci 2018; 285:20180836. [PMID: 30051836 PMCID: PMC6083266 DOI: 10.1098/rspb.2018.0836] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 06/26/2018] [Indexed: 12/23/2022] Open
Abstract
'Sperm competition'-where ejaculates from two or more males compete for fertilization-and 'cryptic female choice'-where females bias this contest to suit their reproductive interests-are now part of the everyday lexicon of sexual selection. Yet the physiological processes that underlie these post-ejaculatory episodes of sexual selection remain largely enigmatic. In this review, we focus on a range of post-ejaculatory cellular- and molecular-level processes, known to be fundamental for fertilization across most (if not all) sexually reproducing species, and point to their putative role in facilitating sexual selection at the level of the cells and gametes, called 'gamete-mediated mate choice' (GMMC). In this way, we collate accumulated evidence for GMMC across different mating systems, and emphasize the evolutionary significance of such non-random interactions among gametes. Our overall aim in this review is to build a more inclusive view of sexual selection by showing that mate choice often acts in more nuanced ways than has traditionally been assumed. We also aim to bridge the conceptual divide between proximal mechanisms of reproduction, and adaptive explanations for patterns of non-random sperm-egg interactions that are emerging across an increasingly diverse array of taxa.
Collapse
Affiliation(s)
- Jukka Kekäläinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Jonathan P Evans
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
| |
Collapse
|
29
|
Abstract
All animal oocytes are surrounded by a glycoproteinaceous egg coat, a specialized extracellular matrix that serves both structural and species-specific roles during fertilization. Egg coat glycoproteins polymerize into the extracellular matrix of the egg coat using a conserved protein-protein interaction module-the zona pellucida (ZP) domain-common to both vertebrates and invertebrates, suggesting that the basic structural features of egg coats have been conserved across hundreds of millions of years of evolution. Egg coat proteins, as with other proteins involved in reproduction, are frequently found to be rapidly evolving. Given that gamete compatibility must be maintained for the fitness of sexually reproducing organisms, this finding is somewhat paradoxical and suggests a role for adaptive diversification in reproductive protein evolution. Here we review the structure and function of metazoan egg coat proteins, with an emphasis on the potential role their evolution has played in the creation and maintenance of species boundaries.
Collapse
Affiliation(s)
- Emily E Killingbeck
- Department of Genome Sciences, University of Washington, Seattle, WA, United States.
| | - Willie J Swanson
- Department of Genome Sciences, University of Washington, Seattle, WA, United States.
| |
Collapse
|
30
|
Firman RC. Postmating sexual conflict and female control over fertilization during gamete interaction. Ann N Y Acad Sci 2018. [DOI: 10.1111/nyas.13635] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Renée C. Firman
- Centre for Evolutionary Biology University of Western Australia Western Australia Australia
| |
Collapse
|
31
|
Geßner C, Johnson SL, Fisher P, Clarke S, Rutherford K, Symonds J, Gemmell NJ. Male-female relatedness at specific SNP-linkage groups influences cryptic female choice in Chinook salmon ( Oncorhynchus tshawytscha). Proc Biol Sci 2018; 284:rspb.2017.0853. [PMID: 28747474 DOI: 10.1098/rspb.2017.0853] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/13/2017] [Indexed: 12/14/2022] Open
Abstract
In a range of taxa, the relatedness between mates influences both pre- and post-mating processes of sexual selection. However, relatively little is known about the genetic loci facilitating such a bias, with the exception of the major histocompatibility complex. Here, we performed tightly controlled replicated in vitro fertilization trials to explore the impact of relatedness on two possible mechanisms of cryptic female choice (CFC) in Chinook salmon (Oncorhynchus tshawytscha). We tested (i) whether relatedness of mates, assessed using 682 single nucleotide polymorphisms (SNPs) on 29 SNP-linkage groups (LGs), biases a male's sperm velocity in ovarian fluid (a parameter previously shown to predict male fertilization success), and (ii) whether relatedness of mates governs fertilization success via other mechanisms, probably via sperm-egg interactions. We found that relatedness on three LGs explained the variation in sperm velocity, and relatedness on two LGs explained fertilization success, which might indicate the presence of genes important in sperm-ovarian fluid and sperm-egg interactions in these genomic regions. Mapping of the SNPs on these LGs to the rainbow trout genome revealed two genes that affect fertility in humans and represent candidate genes for further studies. Our results thereby provide a novel contribution to the understanding of the mechanism of CFC.
Collapse
Affiliation(s)
- Cornelia Geßner
- Allan Wilson Centre, Department of Anatomy, University of Otago, 270 Great King Street, Dunedin 9016, New Zealand
| | - Sheri L Johnson
- Allan Wilson Centre, Department of Anatomy, University of Otago, 270 Great King Street, Dunedin 9016, New Zealand.,Department of Zoology, University of Otago, 340 Great King Street, Dunedin 9016, New Zealand
| | - Paul Fisher
- AgResearch, Invermay Agricultural Centre, Puddle Alley, Mosgiel 9053, New Zealand
| | - Shannon Clarke
- AgResearch, Invermay Agricultural Centre, Puddle Alley, Mosgiel 9053, New Zealand
| | - Kim Rutherford
- Allan Wilson Centre, Department of Anatomy, University of Otago, 270 Great King Street, Dunedin 9016, New Zealand
| | - Jane Symonds
- National Institute of Water and Atmospheric Research, Bream Bay Aquaculture Park, Station Road, Ruakaka 0116, New Zealand
| | - Neil J Gemmell
- Allan Wilson Centre, Department of Anatomy, University of Otago, 270 Great King Street, Dunedin 9016, New Zealand
| |
Collapse
|
32
|
Hart MW, Stover DA, Guerra V, Mozaffari SV, Ober C, Mugal CF, Kaj I. Positive selection on human gamete-recognition genes. PeerJ 2018; 6:e4259. [PMID: 29340252 PMCID: PMC5767332 DOI: 10.7717/peerj.4259] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/21/2017] [Indexed: 01/29/2023] Open
Abstract
Coevolution of genes that encode interacting proteins expressed on the surfaces of sperm and eggs can lead to variation in reproductive compatibility between mates and reproductive isolation between members of different species. Previous studies in mice and other mammals have focused in particular on evidence for positive or diversifying selection that shapes the evolution of genes that encode sperm-binding proteins expressed in the egg coat or zona pellucida (ZP). By fitting phylogenetic models of codon evolution to data from the 1000 Genomes Project, we identified candidate sites evolving under diversifying selection in the human genes ZP3 and ZP2. We also identified one candidate site under positive selection in C4BPA, which encodes a repetitive protein similar to the mouse protein ZP3R that is expressed in the sperm head and binds to the ZP at fertilization. Results from several additional analyses that applied population genetic models to the same data were consistent with the hypothesis of selection on those candidate sites leading to coevolution of sperm- and egg-expressed genes. By contrast, we found no candidate sites under selection in a fourth gene (ZP1) that encodes an egg coat structural protein not directly involved in sperm binding. Finally, we found that two of the candidate sites (in C4BPA and ZP2) were correlated with variation in family size and birth rate among Hutterite couples, and those two candidate sites were also in linkage disequilibrium in the same Hutterite study population. All of these lines of evidence are consistent with predictions from a previously proposed hypothesis of balancing selection on epistatic interactions between C4BPA and ZP3 at fertilization that lead to the evolution of co-adapted allele pairs. Such patterns also suggest specific molecular traits that may be associated with both natural reproductive variation and clinical infertility.
Collapse
Affiliation(s)
- Michael W Hart
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Daryn A Stover
- School of Mathematical and Natural Sciences, Arizona State University Colleges at Lake Havasu City, Lake Havasu City, AZ, USA
| | - Vanessa Guerra
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Sahar V Mozaffari
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Carole Ober
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Carina F Mugal
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Ingemar Kaj
- Department of Mathematics, Uppsala University, Uppsala, Sweden
| |
Collapse
|
33
|
González AM, Prada CA, Ávila V, Medina M. Ecological Speciation in Corals. POPULATION GENOMICS 2018. [DOI: 10.1007/13836_2018_35] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
34
|
Monro K, Marshall DJ. Unravelling anisogamy: egg size and ejaculate size mediate selection on morphology in free-swimming sperm. Proc Biol Sci 2017; 283:rspb.2016.0671. [PMID: 27412273 DOI: 10.1098/rspb.2016.0671] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/20/2016] [Indexed: 01/28/2023] Open
Abstract
Gamete dimorphism (anisogamy) defines the sexes in most multicellular organisms. Theoretical explanations for its maintenance usually emphasize the size-related selection pressures of sperm competition and zygote survival, assuming that fertilization of all eggs precludes selection for phenotypes that enhance fertility. In external fertilizers, however, fertilization is often incomplete due to sperm limitation, and the risk of polyspermy weakens the advantage of high sperm numbers that is predicted to limit sperm size, allowing alternative selection pressures to target free-swimming sperm. We asked whether egg size and ejaculate size mediate selection on the free-swimming sperm of Galeolaria caespitosa, a marine tubeworm with external fertilization, by comparing relationships between sperm morphology and male fertility across manipulations of egg size and sperm density. Our results suggest that selection pressures exerted by these factors may aid the maintenance of anisogamy in external fertilizers by limiting the adaptive value of larger sperm in the absence of competition. In doing so, our study offers a more complete explanation for the stability of anisogamy across the range of sperm environments typical of this mating system and identifies new potential for the sexes to coevolve via mutual selection pressures exerted by gametes at fertilization.
Collapse
Affiliation(s)
- Keyne Monro
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Dustin J Marshall
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| |
Collapse
|
35
|
Lymbery RA, Kennington WJ, Evans JP. Egg chemoattractants moderate intraspecific sperm competition. Evol Lett 2017; 1:317-327. [PMID: 30283659 PMCID: PMC6121861 DOI: 10.1002/evl3.34] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/10/2017] [Indexed: 12/20/2022] Open
Abstract
Interactions among eggs and sperm are often assumed to generate intraspecific variation in reproductive fitness, but the specific gamete-level mechanisms underlying competitive fertilization success remain elusive in most species. Sperm chemotaxis-the attraction of sperm by egg-derived chemicals-is a ubiquitous form of gamete signaling, occurring throughout the animal and plant kingdoms. The chemical cues released by eggs are known to act at the interspecific level (e.g., facilitating species recognition), but recent studies have suggested that they could have roles at the intraspecific level by moderating sperm competition. Here, we exploit the experimental tractability of a broadcast spawning marine invertebrate to test this putative mechanism of gamete-level sexual selection. We use a fluorescently labeled mitochondrial dye in mussels to track the real-time success of sperm as they compete to fertilize eggs, and provide the first direct evidence in any species that competitive fertilization success is moderated by differential sperm chemotaxis. Furthermore, our data are consistent with the idea that egg chemoattractants selectively attract ejaculates from genetically compatible males, based on relationships inferred from both nuclear and mitochondrial genetic markers. These findings for a species that exhibits the ancestral reproductive strategy of broadcast spawning have important implications for the numerous species that also rely on egg chemoattractants to attract sperm, including humans, and have potentially important implications for our understanding of the evolutionary cascade of sexual selection.
Collapse
Affiliation(s)
- Rowan A. Lymbery
- School of Biological SciencesThe University of Western AustraliaCrawleyWA 6009Australia
| | - W. Jason Kennington
- School of Biological SciencesThe University of Western AustraliaCrawleyWA 6009Australia
| | - Jonathan P. Evans
- School of Biological SciencesThe University of Western AustraliaCrawleyWA 6009Australia
| |
Collapse
|
36
|
Couvray S, Coupé S. Three-year monitoring of genetic diversity reveals a micro-connectivity pattern and local recruitment in the broadcast marine species Paracentrotus lividus. Heredity (Edinb) 2017; 120:110-124. [PMID: 29180717 DOI: 10.1038/s41437-017-0013-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 09/14/2017] [Accepted: 09/23/2017] [Indexed: 12/20/2022] Open
Abstract
In conservation and management of marine biological resources, a knowledge of connectivity is necessary to understand how local populations are naturally replenished by the arrival of new recruits from source populations. At small geographical scales, species experiencing moderate to long pelagic larval phases are mostly genetically homogeneous, which hinders inferences about local connectivity. Recent studies demonstrated that assessing genetic relatedness and kinship could provide information about local connectivity in populations with high levels of gene flow. Here, we were interested in deciphering the structure and connectivity of populations of the sea urchin Paracentrotus lividus, by monitoring populations at 11 localities distributed along a 225-km coast-line in the south-eastern French Mediterranean Sea. Using 12 microsatellite loci, we found a weak but significant genetic differentiation and observed a transient genetic differentiation among locations within temporal cohorts, without any correlation with the distance between locations, interpreted as unexplainable chaotic genetic patchiness. Among temporal cohorts, the more related individuals were mainly found within locations and the observed local differentiation (FST) correlated with the proportion of kin within locations, suggesting that larvae dispersed cohesively. Specifically, we could also reveal that populations flanking Cape Sicié were influenced by eastern populations and that local recruitment was a frequent occurrence. Overall, our results contribute to the growing number of studies showing that connectivity can be reliably assessed at a fine spatial scale even in genetically homogenous populations.
Collapse
Affiliation(s)
- Sylvain Couvray
- Institut Océanographique Paul Ricard, Ile des Embiez, 83140, Six-Fours-Les-Plages, France
| | - Stéphane Coupé
- Univ Toulon, Aix Marseille Univ, CNRS/INSU, IRD, MIO UM 110, Mediterranean Institute of Oceanography, La Garde, France.
| |
Collapse
|
37
|
Levitan DR. Do Sperm Really Compete and Do Eggs Ever Have a Choice? Adult Distribution and Gamete Mixing Influence Sexual Selection, Sexual Conflict, and the Evolution of Gamete Recognition Proteins in the Sea. Am Nat 2017; 191:88-105. [PMID: 29244565 DOI: 10.1086/694780] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The evolution of gametic compatibility and the effectiveness of compatibility, within and across species, depend on whether sperm from different males directly compete for an egg and whether eggs ever have a choice. Direct sperm competition and egg choice depend on whether sperm from different males arrive at an egg in the brief interval between first sperm contact and fertilization. Although this process may be relevant for all sexually reproducing organisms, it is most easily examined in aquatic external fertilizers. When sperm are released into the sea, packets of seawater at the spatial scale relevant to single eggs might contain sperm from only one male, eliminating the potential for direct sperm competition and egg choice. Field experiments and a simple heuristic model examining the degree of sperm mixing for the sea urchin Strongylocentrotus franciscanus indicate that degree of competitive fertilization depends on density and distribution of competing males and that the nature of this competition influences whether males with high- or low-affinity gamete recognition protein genotypes have higher reproductive success. These results provide a potential explanation for the generation and maintenance of variation in gamete recognition proteins and why effectiveness of conspecific sperm precedence can be density dependent.
Collapse
|
38
|
Shi W, Han Y, Guo C, Zhao X, Liu S, Su W, Wang Y, Zha S, Chai X, Liu G. Ocean acidification hampers sperm-egg collisions, gamete fusion, and generation of Ca 2+ oscillations of a broadcast spawning bivalve, Tegillarca granosa. MARINE ENVIRONMENTAL RESEARCH 2017; 130:106-112. [PMID: 28750793 DOI: 10.1016/j.marenvres.2017.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/15/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
Although the effect of ocean acidification on fertilization success of marine organisms is increasingly well documented, the underlying mechanisms are not completely understood. The fertilization success of broadcast spawning invertebrates depends on successful sperm-egg collisions, gamete fusion, and standard generation of Ca2+ oscillations. Therefore, the realistic effects of future ocean pCO2 levels on these specific aspects of fertilization of Tegillarca granosa were investigated in the present study through sperm velocity trials, fertilization kinetics model analysis, and intracellular Ca2+ assays, respectively. Results obtained indicated that ocean acidification significantly reduced the fertilization success of T. granosa, which could be accountable by (i) decreased sperm velocity hence reducing the probability for sperm-egg collisions; (ii) lowered probability of gamete fusion for each gamete collision event; and (iii) disrupted intracellular Ca2+ oscillations.
Collapse
Affiliation(s)
- Wei Shi
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Yu Han
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Cheng Guo
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Xinguo Zhao
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Saixi Liu
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Wenhao Su
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Yichen Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Shanjie Zha
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Xueliang Chai
- Zhejiang Mariculture Research Institute, Wenzhou, PR China
| | - Guangxu Liu
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China.
| |
Collapse
|
39
|
Springate L, Frasier TR. Gamete compatibility genes in mammals: candidates, applications and a potential path forward. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170577. [PMID: 28878999 PMCID: PMC5579115 DOI: 10.1098/rsos.170577] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/31/2017] [Indexed: 06/01/2023]
Abstract
Fertilization represents a critical stage in biology, where successful alleles of a previous generation are shuffled into new arrangements and subjected to the forces of selection in the next generation. Although much research has been conducted on how variation in morphological and behavioural traits lead to variation in fertilization patterns, surprisingly little is known about fertilization at a molecular level, and specifically about how genes expressed on the sperm and egg themselves influence fertilization patterns. In mammals, several genes have been identified whose products are expressed on either the sperm or the egg, and which influence the fertilization process, but the specific mechanisms are not yet known. Additionally, in 2014 an interacting pair of proteins was identified: 'Izumo' on the sperm, and 'Juno' on the egg. With the identification of these genes comes the first opportunity to understand the molecular aspects of fertilization in mammals, and to identify how the genetic characteristics of these genes influence fertilization patterns. Here, we review recent progress in our understanding of fertilization and gamete compatibility in mammals, which should provide a helpful guide to researchers interested in untangling the molecular mechanisms of fertilization and the resulting impacts on population biology and evolutionary processes.
Collapse
|
40
|
Effects of the Ordering of Natural Selection and Population Regulation Mechanisms on Wright-Fisher Models. G3-GENES GENOMES GENETICS 2017; 7:2095-2106. [PMID: 28500051 PMCID: PMC5499119 DOI: 10.1534/g3.117.041038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We explore the effect of different mechanisms of natural selection on the evolution of populations for one- and two-locus systems. We compare the effect of viability and fecundity selection in the context of the Wright-Fisher model with selection under the assumption of multiplicative fitness. We show that these two modes of natural selection correspond to different orderings of the processes of population regulation and natural selection in the Wright-Fisher model. We find that under the Wright-Fisher model these two different orderings can affect the distribution of trajectories of haplotype frequencies evolving with genetic recombination. However, the difference in the distribution of trajectories is only appreciable when the population is in significant linkage disequilibrium. We find that as linkage disequilibrium decays the trajectories for the two different models rapidly become indistinguishable. We discuss the significance of these findings in terms of biological examples of viability and fecundity selection, and speculate that the effect may be significant when factors such as gene migration maintain a degree of linkage disequilibrium.
Collapse
|
41
|
Paternity success depends on male genetic characteristics in the terrestrial isopod Armadillidium vulgare. Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2317-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
42
|
Lehnert SJ, Butts IAE, Flannery EW, Peters KM, Heath DD, Pitcher TE. Effects of ovarian fluid and genetic differences on sperm performance and fertilization success of alternative reproductive tactics in Chinook salmon. J Evol Biol 2017; 30:1236-1245. [PMID: 28387056 DOI: 10.1111/jeb.13088] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 03/03/2017] [Accepted: 03/30/2017] [Indexed: 12/20/2022]
Abstract
In many species, sperm velocity affects variation in the outcome of male competitive fertilization success. In fishes, ovarian fluid (OF) released with the eggs can increase male sperm velocity and potentially facilitate cryptic female choice for males of specific phenotypes and/or genotypes. Therefore, to investigate the effect of OF on fertilization success, we measured sperm velocity and conducted in vitro competitive fertilizations with paired Chinook salmon (Oncorhynchus tshawytscha) males representing two alternative reproductive tactics, jacks (small sneaker males) and hooknoses (large guarding males), in the presence of river water alone and OF mixed with river water. To determine the effect of genetic differences on fertilization success, we genotyped fish at neutral (microsatellites) and functional [major histocompatibility complex (MHC) II ß1] markers. We found that when sperm were competed in river water, jacks sired significantly more offspring than hooknoses; however, in OF, there was no difference in paternity between the tactics. Sperm velocity was significantly correlated with paternity success in river water, but not in ovarian fluid. Paternity success in OF, but not in river water alone, was correlated with genetic relatedness between male and female, where males that were less related to the female attained greater paternity. We found no relationship between MHC II ß1 divergence between mates and paternity success in water or OF. Our results indicate that OF can influence the outcome of sperm competition in Chinook salmon, where OF provides both male tactics with fertilization opportunities, which may in part explain what maintains both tactics in nature.
Collapse
Affiliation(s)
- S J Lehnert
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - I A E Butts
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, USA
| | - E W Flannery
- Department of Biological Sciences, University of Windsor, Windsor, ON, Canada
| | - K M Peters
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada.,Department of Biological Sciences, University of Windsor, Windsor, ON, Canada
| | - D D Heath
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada.,Department of Biological Sciences, University of Windsor, Windsor, ON, Canada
| | - T E Pitcher
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada.,Department of Biological Sciences, University of Windsor, Windsor, ON, Canada
| |
Collapse
|
43
|
Lewis JA, Pitcher TE. Tactic-specific benefits of polyandry in Chinook salmon Oncorhynchus tshawytscha. JOURNAL OF FISH BIOLOGY 2017; 90:1244-1256. [PMID: 27873318 DOI: 10.1111/jfb.13223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 10/18/2016] [Indexed: 06/06/2023]
Abstract
This study examined whether polyandrous female Chinook salmon Oncorhynchus tshawytscha obtain benefits compared with monandrous females through an increase in hatching success. Both of the alternative reproductive tactics present in male O. tshawytscha (large hooknoses and small, precocious jacks) were used, such that eggs were either fertilized by a single male (from each tactic) or multiple males (using two males from the same or different tactics). The results show that fertilized eggs from the polyandrous treatments had a significantly higher hatching success than those from the monandrous treatments. It is also shown that sperm speed was positively related with offspring hatching success. Finally, there were tactic-specific effects on the benefits females received. The inclusion of jacks in any cross resulted in offspring with higher hatching success, with the cross that involved a male from each tactic providing offspring with the highest hatching success than any other cross. This study has important implications for the evolution of multiple mating and why it is so prevalent across taxa, while also providing knowledge on the evolution of mating systems, specifically those with alternative reproductive tactics.
Collapse
Affiliation(s)
- J A Lewis
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| | - T E Pitcher
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
- Department of Biological Sciences, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| |
Collapse
|
44
|
Hussain YH, Sadilek M, Salad S, Zimmer RK, Riffell JA. Individual female differences in chemoattractant production change the scale of sea urchin gamete interactions. Dev Biol 2017; 422:186-197. [PMID: 28088316 DOI: 10.1016/j.ydbio.2017.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 01/02/2017] [Accepted: 01/10/2017] [Indexed: 01/13/2023]
Abstract
Sperm selection by females is an important process influencing fertilization and, particularly in broadcast-spawning organisms, often occurs before sperm reach the egg. Waterborne sperm chemoattractants are one mechanism by which eggs selectively influence conspecific sperm behavior, but it remains an open question whether the eggs from different females produce different amounts of sperm chemoattractant, and how that might influence sperm behavior. Here, we quantify the differences in attractant production between females of the sea urchin species Lytechinus pictus and use computational models and microfluidic sperm chemotaxis assays to determine how differences in chemoattractant production between females affects their ability to attract sperm. Our study demonstrates that there is significant individual female variation in egg chemoattractant production, and that this variation changes the scope and strength of sperm attraction. These results provide evidence for the importance of individual female variability in differential sperm attraction and fertilization success.
Collapse
Affiliation(s)
- Yasmeen H Hussain
- University of Washington, Department of Biology, Seattle, WA 98195, USA
| | - Martin Sadilek
- University of Washington, Department of Chemistry, Seattle, WA 98195, USA
| | - Shukri Salad
- University of Washington, Department of Biology, Seattle, WA 98195, USA
| | - Richard K Zimmer
- University of California Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, CA 90095, USA
| | - Jeffrey A Riffell
- University of Washington, Department of Biology, Seattle, WA 98195, USA
| |
Collapse
|
45
|
Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha). Heredity (Edinb) 2017; 118:442-452. [PMID: 28051059 DOI: 10.1038/hdy.2016.116] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/28/2016] [Accepted: 11/01/2016] [Indexed: 12/17/2022] Open
Abstract
Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm-egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm-egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm-egg interactions.
Collapse
|
46
|
Beekman M, Nieuwenhuis B, Ortiz-Barrientos D, Evans JP. Sexual selection in hermaphrodites, sperm and broadcast spawners, plants and fungi. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150541. [PMID: 27619704 PMCID: PMC5031625 DOI: 10.1098/rstb.2015.0541] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2016] [Indexed: 11/12/2022] Open
Abstract
Darwin was the first to recognize that sexual selection is a strong evolutionary force. Exaggerated traits allow same-sex individuals to compete over access to mates and provide a mechanism by which mates are selected. It is relatively easy to appreciate how inter- and intrasexual selection work in organisms with the sensory capabilities to perceive physical or behavioural traits that signal mate quality or mate compatibility, and to assess the relative quality of competitors. It is therefore not surprising that most studies of sexual selection have focused on animals with separate sexes and obvious adaptations that function in the context of reproductive competition. Yet, many sexual organisms are both male and female at the same time, often lack sexual dimorphism and never come into direct contact at mating. How does sexual selection act in such species, and what can we learn from them? Here, we address these questions by exploring the potential for sexual selection in simultaneous hermaphrodites, sperm- and broadcast spawners, plants and fungi. Our review reveals a range of mechanisms of sexual selection, operating primarily after gametes have been released, which are common in many of these groups and also quite possibly in more familiar (internally fertilizing and sexually dimorphic) organisms.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.
Collapse
Affiliation(s)
- Madeleine Beekman
- School of Life and Environmental Sciences, University of Sydney, 2006 New South Wales, Australia
| | - Bart Nieuwenhuis
- Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | | | - Jonathan P Evans
- Centre for Evolutionary Biology, School of Animal Biology, University of Western Australia, 6009 Western Australia, Australia
| |
Collapse
|
47
|
Lehnert SJ, Heath DD, Devlin RH, Pitcher TE. Post-spawning sexual selection in red and white Chinook salmon (Oncorhynchus tshawytscha). Behav Ecol 2016. [DOI: 10.1093/beheco/arw142] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
|
48
|
Ducret V, Gaigher A, Simon C, Goudet J, Roulin A. Sex-specific allelic transmission bias suggests sexual conflict at MC1R. Mol Ecol 2016; 25:4551-63. [PMID: 27480981 DOI: 10.1111/mec.13781] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 02/03/2023]
Abstract
Sexual conflict arises when selection in one sex causes the displacement of the other sex from its phenotypic optimum, leading to an inevitable tension within the genome - called intralocus sexual conflict. Although the autosomal melanocortin-1-receptor gene (MC1R) can generate colour variation in sexually dichromatic species, most previous studies have not considered the possibility that MC1R may be subject to sexual conflict. In the barn owl (Tyto alba), the allele MC1RWHITE is associated with whitish plumage coloration, typical of males, and the allele MC1RRUFOUS is associated with dark rufous coloration, typical of females, although each sex can express any phenotype. Because each colour variant is adapted to specific environmental conditions, the allele MC1RWHITE may be more strongly selected in males and the allele MC1RRUFOUS in females. We therefore investigated whether MC1R genotypes are in excess or deficit in male and female fledglings compared with the expected Hardy-Weinberg proportions. Our results show an overall deficit of 7.5% in the proportion of heterozygotes in males and of 12.9% in females. In males, interannual variation in assortative pairing with respect to MC1R explained the year-specific deviations from Hardy-Weinberg proportions, whereas in females, the deficit was better explained by the interannual variation in the probability of inheriting the MC1RWHITE or MC1RRUFOUS allele. Additionally, we observed that sons inherit the MC1RRUFOUS allele from their fathers on average slightly less often than expected under the first Mendelian law. Transmission ratio distortion may be adaptive in this sexually dichromatic species if males and females are, respectively, selected to display white and rufous plumages.
Collapse
Affiliation(s)
- Valérie Ducret
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland.
| | - Arnaud Gaigher
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
| | - Céline Simon
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
| | - Jérôme Goudet
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
| | - Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
| |
Collapse
|
49
|
Ocean acidification changes the male fitness landscape. Sci Rep 2016; 6:31250. [PMID: 27531458 PMCID: PMC4987666 DOI: 10.1038/srep31250] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/15/2016] [Indexed: 01/29/2023] Open
Abstract
Sperm competition is extremely common in many ecologically important marine taxa. Ocean acidification (OA) is driving rapid changes to the marine environments in which freely spawned sperm operate, yet the consequences of OA on sperm performance are poorly understood in the context of sperm competition. Here, we investigated the impacts of OA (+1000 μatm pCO2) on sperm competitiveness for the sea urchin Paracentrotus lividus. Males with faster sperm had greater competitive fertilisation success in both seawater conditions. Similarly, males with more motile sperm had greater sperm competitiveness, but only under current pCO2 levels. Under OA the strength of this association was significantly reduced and there were male sperm performance rank changes under OA, such that the best males in current conditions are not necessarily best under OA. Therefore OA will likely change the male fitness landscape, providing a mechanism by which environmental change alters the genetic landscape of marine species.
Collapse
|
50
|
Alonzo SH, Stiver KA, Marsh-Rollo SE. Ovarian fluid allows directional cryptic female choice despite external fertilization. Nat Commun 2016; 7:12452. [PMID: 27529581 PMCID: PMC4990696 DOI: 10.1038/ncomms12452] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 07/04/2016] [Indexed: 12/11/2022] Open
Abstract
In species with internal fertilization, females can favour certain males over others, not only before mating but also within the female's reproductive tract after mating. Here, we ask whether such directional post-mating (that is, cryptic) female mate choice can also occur in species with external fertilization. Using an in vitro sperm competition experiment, we demonstrate that female ovarian fluid (ovarian fluid) changes the outcome of sperm competition by decreasing the importance of sperm number thereby increasing the relative importance of sperm velocity. We further show that ovarian fluid does not differentially affect sperm from alternative male phenotypes, but generally enhances sperm velocity, motility, straightness and chemoattraction. Under natural conditions, female ovarian fluid likely increases the paternity of the preferred parental male phenotype, as these males release fewer but faster sperm. These results imply females have greater control over fertilization and potential to exert selection on males in species with external fertilization than previously thought possible.
Collapse
Affiliation(s)
- Suzanne H. Alonzo
- Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect Street, New Haven, Connecticut 06520, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USA
| | - Kelly A. Stiver
- Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect Street, New Haven, Connecticut 06520, USA
- Psychology Department, Southern Connecticut State University, 501 Crescent Street, New Haven, Connecticut 06515, USA
| | - Susan E. Marsh-Rollo
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USA
- Department of Psychology, Neuroscience, and Behaviour, McMaster University, 1280 Main Street W, Hamilton, Ontario, Canada L8S4K1
| |
Collapse
|