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Class B, Brommer JE. Can dominance genetic variance be ignored in evolutionary quantitative genetic analyses of wild populations? Evolution 2020; 74:1540-1550. [PMID: 32510608 DOI: 10.1111/evo.14034] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 05/06/2020] [Accepted: 05/30/2020] [Indexed: 12/21/2022]
Abstract
Accurately estimating genetic variance components is important for studying evolution in the wild. Empirical work on domesticated and wild outbred populations suggests that dominance genetic variance represents a substantial part of genetic variance, and theoretical work predicts that ignoring dominance can inflate estimates of additive genetic variance. Whether this issue is pervasive in natural systems is unknown, because we lack estimates of dominance variance in wild populations obtained in situ. Here, we estimate dominance and additive genetic variance, maternal variance, and other sources of nongenetic variance in eight traits measured in over 9000 wild nestlings linked through a genetically resolved pedigree. We find that dominance variance, when estimable, does not statistically differ from zero and represents a modest amount (2-36%) of genetic variance. Simulations show that (1) inferences of all variance components for an average trait are unbiased; (2) the power to detect dominance variance is low; (3) ignoring dominance can mildly inflate additive genetic variance and heritability estimates but such inflation becomes substantial when maternal effects are also ignored. These findings hence suggest that dominance is a small source of phenotypic variance in the wild and highlight the importance of proper model construction for accurately estimating evolutionary potential.
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Affiliation(s)
- Barbara Class
- Global Change Ecology Research Group, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD, 4556, Australia.,Department of Biology, University of Turku, University Hill, Turku, 20014, Finland
| | - Jon E Brommer
- Department of Biology, University of Turku, University Hill, Turku, 20014, Finland
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2
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Litzke V, Ottensmann M, Forcada J, Heitzmann L, Ivan Hoffman J. Heterozygosity at neutral and immune loci is not associated with neonatal mortality due to microbial infection in Antarctic fur seals. Ecol Evol 2019; 9:7985-7996. [PMID: 31380066 PMCID: PMC6662382 DOI: 10.1002/ece3.5317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/02/2019] [Accepted: 05/08/2019] [Indexed: 11/08/2022] Open
Abstract
Numerous studies have reported correlations between the heterozygosity of genetic markers and fitness. These heterozygosity-fitness correlations (HFCs) play a central role in evolutionary and conservation biology, yet their mechanistic basis remains open to debate. For example, fitness associations have been widely reported at both neutral and functional loci, yet few studies have directly compared the two, making it difficult to gauge the relative contributions of genome-wide inbreeding and specific functional genes to fitness. Here, we compared the effects of neutral and immune gene heterozygosity on death from bacterial infection in Antarctic fur seal (Arctocephalus gazella) pups. We specifically developed a panel of 13 microsatellites from expressed immune genes and genotyped these together with 48 neutral loci in 234 individuals, comprising 39 pups that were classified at necropsy as having most likely died of bacterial infection together with a five times larger matched sample of healthy surviving pups. Identity disequilibrium quantified from the neutral markers was positive and significant, indicative of variance in inbreeding within the study population. However, multilocus heterozygosity did not differ significantly between healthy and infected pups at either class of marker, and little evidence was found for fitness associations at individual loci. These results support a previous study of Antarctic fur seals that found no effects of heterozygosity at nine neutral microsatellites on neonatal survival and thereby help to refine our understanding of how HFCs vary across the life cycle. Given that nonsignificant HFCs are underreported in the literature, we also hope that our study will contribute toward a more balanced understanding of the wider importance of this phenomenon.
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Affiliation(s)
- Vivienne Litzke
- Department of Animal BehaviourBielefeld UniversityBielefeldGermany
| | | | | | | | - Joseph Ivan Hoffman
- Department of Animal BehaviourBielefeld UniversityBielefeldGermany
- British Antarctic Survey, High CrossCambridgeUK
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3
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Head ML, Kahn AT, Henshaw JM, Keogh JS, Jennions MD. Sexual selection on male body size, genital length and heterozygosity: Consistency across habitats and social settings. J Anim Ecol 2017; 86:1458-1468. [PMID: 28815592 DOI: 10.1111/1365-2656.12742] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/30/2017] [Indexed: 12/22/2022]
Abstract
Spatial and temporal variation in environmental factors and the social setting can help to maintain genetic variation in sexually selected traits if it affects the strength of directional selection. A key social parameter which affects the intensity of, and sometimes predicts the response to, mating competition is the operational sex ratio (OSR; ratio of receptive males to females). How the OSR affects selection for specific male traits is poorly understood. It is also unclear how sexual selection is affected by interactions between the OSR and environmental factors, such as habitat complexity, that alter key male-female interactions such as mate encounter rates. Here, we experimentally manipulated the OSR and habitat complexity and quantified sexual selection on male mosquitofish (Gambusia holbrooki) by directly measuring male reproductive success (i.e. paternity). We show that despite a more equitable sharing of paternity (i.e. higher levels of multiple paternity) under a male-biased OSR, selection on focal male traits was unaffected by the OSR or habitat complexity. Instead, sexual selection consistently, and significantly, favoured smaller bodied males, males with higher genome wide heterozygosity (based on >3,000 SNP markers) and males with a relatively long gonopodium (intromittent organ). Our results show that sexual selection on male body size, relative genital size and heterozygosity in this system is consistent across environments that vary in ecological parameters that are expected to influence mate encounter rates.
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Affiliation(s)
- Megan L Head
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia
| | - Andrew T Kahn
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia
| | - Jonathan M Henshaw
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia
| | - J Scott Keogh
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia
| | - Michael D Jennions
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia
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4
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Phillips KP, Jorgensen TH, Jolliffe KG, Richardson DS. Evidence of opposing fitness effects of parental heterozygosity and relatedness in a critically endangered marine turtle? J Evol Biol 2017; 30:1953-1965. [PMID: 28787533 DOI: 10.1111/jeb.13152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 07/27/2017] [Accepted: 07/31/2017] [Indexed: 01/13/2023]
Abstract
How individual genetic variability relates to fitness is important in understanding evolution and the processes affecting populations of conservation concern. Heterozygosity-fitness correlations (HFCs) have been widely used to study this link in wild populations, where key parameters that affect both variability and fitness, such as inbreeding, can be difficult to measure. We used estimates of parental heterozygosity and genetic similarity ('relatedness') derived from 32 microsatellite markers to explore the relationship between genetic variability and fitness in a population of the critically endangered hawksbill turtle, Eretmochelys imbricata. We found no effect of maternal MLH (multilocus heterozygosity) on clutch size or egg success rate, and no single-locus effects. However, we found effects of paternal MLH and parental relatedness on egg success rate that interacted in a way that may result in both positive and negative effects of genetic variability. Multicollinearity in these tests was within safe limits, and null simulations suggested that the effect was not an artefact of using paternal genotypes reconstructed from large samples of offspring. Our results could imply a tension between inbreeding and outbreeding depression in this system, which is biologically feasible in turtles: female-biased natal philopatry may elevate inbreeding risk and local adaptation, and both processes may be disrupted by male-biased dispersal. Although this conclusion should be treated with caution due to a lack of significant identity disequilibrium, our study shows the importance of considering both positive and negative effects when assessing how variation in genetic variability affects fitness in wild systems.
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Affiliation(s)
- K P Phillips
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK.,NERC Biomolecular Analysis Facility (NBAF), Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.,Evolutionary Biology Group, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - T H Jorgensen
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK.,Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - K G Jolliffe
- Victoria, Mahé, Republic of Seychelles.,Drie Kuilen Private Nature Reserve, Breede River District, South Africa
| | - D S Richardson
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
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5
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Vega‐Trejo R, Head ML, Keogh JS, Jennions MD. Experimental evidence for sexual selection against inbred males. J Anim Ecol 2017; 86:394-404. [DOI: 10.1111/1365-2656.12615] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/24/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Regina Vega‐Trejo
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
| | - Megan L. Head
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
| | - J. Scott Keogh
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
| | - Michael D. Jennions
- Division of Ecology and Evolution, Research School of Biology The Australian National University, Acton Canberra ACT 2601 Australia
- Wissenschaftskolleg zu Berlin Wallotstraße 19 14193 Berlin Germany
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6
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No facultative manipulation of offspring sex ratio in relation to parental genetic characteristics in a bird with sex-specific heterozygosity-fitness correlation. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2119-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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7
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Santure AW, Poissant J, De Cauwer I, van Oers K, Robinson MR, Quinn JL, Groenen MAM, Visser ME, Sheldon BC, Slate J. Replicated analysis of the genetic architecture of quantitative traits in two wild great tit populations. Mol Ecol 2015; 24:6148-62. [PMID: 26661500 PMCID: PMC4738425 DOI: 10.1111/mec.13452] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 10/25/2015] [Accepted: 11/02/2015] [Indexed: 01/07/2023]
Abstract
Currently, there is much debate on the genetic architecture of quantitative traits in wild populations. Is trait variation influenced by many genes of small effect or by a few genes of major effect? Where is additive genetic variation located in the genome? Do the same loci cause similar phenotypic variation in different populations? Great tits (Parus major) have been studied extensively in long‐term studies across Europe and consequently are considered an ecological ‘model organism’. Recently, genomic resources have been developed for the great tit, including a custom SNP chip and genetic linkage map. In this study, we used a suite of approaches to investigate the genetic architecture of eight quantitative traits in two long‐term study populations of great tits—one in the Netherlands and the other in the United Kingdom. Overall, we found little evidence for the presence of genes of large effects in either population. Instead, traits appeared to be influenced by many genes of small effect, with conservative estimates of the number of contributing loci ranging from 31 to 310. Despite concordance between population‐specific heritabilities, we found no evidence for the presence of loci having similar effects in both populations. While population‐specific genetic architectures are possible, an undetected shared architecture cannot be rejected because of limited power to map loci of small and moderate effects. This study is one of few examples of genetic architecture analysis in replicated wild populations and highlights some of the challenges and limitations researchers will face when attempting similar molecular quantitative genetic studies in free‐living populations.
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Affiliation(s)
- Anna W Santure
- School of Biological Sciences, University of Auckland, Auckland, 1010, New Zealand.,Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Jocelyn Poissant
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.,Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | - Isabelle De Cauwer
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.,Unité Evolution, Ecologie et Paléontologie, UMR 8198, Université de Lille - Sciences et Technologies, 59655 Cedex, Villeneuve d'Ascq, France
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB, Wageningen, The Netherlands
| | - Matthew R Robinson
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.,Queensland Brain Institute, University of Queensland, Brisbane, Qld, 4072, Australia
| | - John L Quinn
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland.,Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, OX1 3PS, UK
| | - Martien A M Groenen
- Animal Breeding and Genomics Centre, Wageningen University, De Elst 1, Wageningen, The Netherlands
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB, Wageningen, The Netherlands
| | - Ben C Sheldon
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, OX1 3PS, UK
| | - Jon Slate
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
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8
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García-Navas V, Cáliz-Campal C, Ferrer ES, Sanz JJ, Ortego J. Heterozygosity at a single locus explains a large proportion of variation in two fitness-related traits in great tits: a general or a local effect? J Evol Biol 2014; 27:2807-19. [DOI: 10.1111/jeb.12539] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 10/29/2014] [Accepted: 10/31/2014] [Indexed: 12/14/2022]
Affiliation(s)
- V. García-Navas
- Grupo de Investigación de la Biodiversidad Genética y Cultural; Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM); Ciudad Real Spain
- Departamento de Ciencias Ambientales; Facultad de Ciencias Ambientales y Bioquímica; Universidad de Castilla-La Mancha; Toledo Spain
- Institute of Evolutionary Biology and Environmental Studies; University of Zurich; Zurich Switzerland
| | - C. Cáliz-Campal
- Grupo de Investigación de la Biodiversidad Genética y Cultural; Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM); Ciudad Real Spain
- Departamento de Ciencias Ambientales; Facultad de Ciencias Ambientales y Bioquímica; Universidad de Castilla-La Mancha; Toledo Spain
| | - E. S. Ferrer
- Departamento de Ciencias Ambientales; Facultad de Ciencias Ambientales y Bioquímica; Universidad de Castilla-La Mancha; Toledo Spain
| | - J. J. Sanz
- Departamento de Ciencias Ambientales; Facultad de Ciencias Ambientales y Bioquímica; Universidad de Castilla-La Mancha; Toledo Spain
- Departamento de Ecología Evolutiva; Museo Nacional de Ciencias Naturales (CSIC); Madrid Spain
| | - J. Ortego
- Conservation and Evolutionary Genetics Group; Department of Integrative Ecology; Estación Biológica de Doñana (EBD-CSIC); Seville Spain
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9
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Canal D, Serrano D, Potti J. Exploring heterozygosity-survival correlations in a wild songbird population: contrasting effects between juvenile and adult stages. PLoS One 2014; 9:e105020. [PMID: 25122217 PMCID: PMC4133379 DOI: 10.1371/journal.pone.0105020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/03/2014] [Indexed: 11/22/2022] Open
Abstract
The relationship between genetic diversity and fitness, a major issue in evolutionary and conservation biology, is expected to be stronger in traits affected by many loci and those directly influencing fitness. Here we explore the influence of heterozygosity measured at 15 neutral markers on individual survival, one of the most important parameters determining individual fitness. We followed individual survival up to recruitment and during subsequent adult life of 863 fledgling pied flycatchers born in two consecutive breeding seasons. Mark-recapture analyses showed that individual heterozygosity did not influence juvenile or adult survival. In contrast, the genetic relatedness of parents was negatively associated with the offspring’s survival during the adult life, but this effect was not apparent in the juvenile (from fledgling to recruitment) stage. Stochastic factors experienced during the first year of life in this long-distance migratory species may have swamped a relationship between heterozygosity and survival up to recruitment.
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Affiliation(s)
- David Canal
- Doñana Biological Station – CSIC, Department of Evolutionary Ecology, Sevilla, Spain
- * E-mail:
| | - David Serrano
- Doñana Biological Station – CSIC, Department of Conservation Biology, Sevilla, Spain
| | - Jaime Potti
- Doñana Biological Station – CSIC, Department of Evolutionary Ecology, Sevilla, Spain
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10
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Sardell RJ, Kempenaers B, DuVal EH. Female mating preferences and offspring survival: testing hypotheses on the genetic basis of mate choice in a wild lekking bird. Mol Ecol 2014; 23:933-46. [DOI: 10.1111/mec.12652] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 12/06/2013] [Accepted: 12/13/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Rebecca J. Sardell
- Department of Biological Science; Florida State University; 319 Stadium Dr. Tallahassee FL 32306-4295 USA
| | - Bart Kempenaers
- Department of Behavioural Ecology and Evolutionary Genetics; Max Planck Institute for Ornithology; Eberhard-Gwinner-Strasse D-82319 Seewiesen Germany
| | - Emily H. DuVal
- Department of Biological Science; Florida State University; 319 Stadium Dr. Tallahassee FL 32306-4295 USA
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11
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While GM, Uller T, Bordogna G, Wapstra E. Promiscuity resolves constraints on social mate choice imposed by population viscosity. Mol Ecol 2014; 23:721-32. [DOI: 10.1111/mec.12618] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 11/22/2013] [Accepted: 11/22/2013] [Indexed: 01/20/2023]
Affiliation(s)
- Geoffrey M. While
- School of Zoology; University of Tasmania; Private Bag 05 Hobart TAS 7001 Australia
- Department of Zoology; Edward Grey Institute; University of Oxford; South Parks Road Oxford OX1 3PS UK
| | - Tobias Uller
- Department of Zoology; Edward Grey Institute; University of Oxford; South Parks Road Oxford OX1 3PS UK
| | - Genevieve Bordogna
- School of Zoology; University of Tasmania; Private Bag 05 Hobart TAS 7001 Australia
- International Services; Slippery Rock University; Slippery Rock PA 16057 USA
| | - Erik Wapstra
- School of Zoology; University of Tasmania; Private Bag 05 Hobart TAS 7001 Australia
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12
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Klauke N, Segelbacher G, Schaefer HM. Reproductive success depends on the quality of helpers in the endangered, cooperative El Oro parakeet (Pyrrhura orcesi). Mol Ecol 2013; 22:2011-27. [PMID: 23397908 DOI: 10.1111/mec.12219] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 12/14/2012] [Accepted: 12/18/2012] [Indexed: 11/29/2022]
Abstract
In cooperative species, helping behaviour and reproductive success can be correlated, but understanding this correlation is often impaired by the difficulty to correctly infer causation. While helpers can incur costs by participating in brood care, it is yet unclear if their help depends on their individual quality. We address these questions in the previously unknown cooperative breeding system of the endangered El Oro parakeet (Pyrrhura orcesi). Specifically, we ask (i) whether breeders benefit directly from helpers by an enhanced reproductive success and if so, (ii) whether the amount of this potential benefit is regulated by the quality of contributing group members. Groups consist of a dominant breeding pair accompanied by helpers, but cooperation is not obligate. Microsatellite heterozygosity was used to assess individual quality; its suitability as indicator of quality was reflected in the positive relationship between offspring heterozygosity and recruitment into the population. The reproductive success of breeding pairs depended on helper (genetic) quality and the number of helpers. This relationship occurred on two different levels: clutch size and fledging success, indicating (i) that females profit from high-quality helpers and probably adjust clutch size accordingly and (ii) that the helpers increase fledging success. Congruently, we found that offspring body condition is positively affected by helper quality, which is most probably explained by the increased feeding rates when helpers are present. We suggest a causal link between cooperation and reproductive success in this frugivorous, endangered parakeet. Further, helper (genetic) quality can be a relevant factor for determining reproductive fitness in cooperative species, particularly in small and bottlenecked populations.
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Affiliation(s)
- Nadine Klauke
- Department of Animal Ecology and Evolution, Faculty of Biology, University of Freiburg, Freiburg, Germany.
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13
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Monceau K, Wattier R, Dechaume-Moncharmont FX, Dubreuil C, Cézilly F. Heterozygosity-fitness correlations in adult and juvenile Zenaida Dove, Zenaida aurita. ACTA ACUST UNITED AC 2012; 104:47-56. [PMID: 23091225 DOI: 10.1093/jhered/ess073] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Understanding how fitness is related to genetic variation is of crucial importance in both evolutionary ecology and conservation biology. We report a study of heterozygosity-fitness correlations in a wild, noninbred population of Zenaida Doves, Zenaida aurita, based on a sample comprising 489 individuals (382 adults and 107 juveniles) typed at 13 microsatellite loci, resulting in a data set comprising 5793 genotypes. In both adults and juveniles, and irrespective of sex, no evidence was found for an effect of either multilocus or single-locus heterozygosity on traits potentially related to fitness such as foraging tactic, competitive ability, and fluctuating asymmetry. In contrast, a significant negative correlation between body condition and multilocus heterozygosity, indicative of outbreeding depression, was found in juveniles, whereas no such trend was observed in adults. However, the frequency distribution of heterozygosity did not differ between the two age classes, suggesting compensatory growth by heterozygous juveniles. We discuss our results in relation to some practical limitations associated with studies of heterozygosity-fitness correlations, and suggest that tropical bird species with allopatric divergence between island populations may provide a good biological model for the detection of outbreeding depression.
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Affiliation(s)
- Karine Monceau
- Université de Bourgogne, UMR CNRS 6282 Biogéosciences, 6 boulevard Gabriel, 21000 Dijon, France.
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14
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Harrison XA, Bearhop S, Inger R, Colhoun K, Gudmundsson GA, Hodgson D, McElwaine G, Tregenza T. Heterozygosity-fitness correlations in a migratory bird: an analysis of inbreeding and single-locus effects. Mol Ecol 2011; 20:4786-95. [PMID: 21973192 DOI: 10.1111/j.1365-294x.2011.05283.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Studies in a multitude of taxa have described a correlation between heterozygosity and fitness and usually conclude that this is evidence for inbreeding depression. Here, we have used multilocus heterozygosity (MLH) estimates from 15 microsatellite markers to show evidence of heterozygosity-fitness correlations (HFCs) in a long-distance migratory bird, the light-bellied Brent goose. We found significant, positive heterozygosity-heterozygosity correlations between random subsets of the markers we employed, and no evidence that a model containing all loci as individual predictors in a multiple regression explained significantly more variation than a model with MLH as a single predictor. Collectively, these results lend support to the hypothesis that the HFCs we have observed are a function of inbreeding depression. However, we do find that fitness correlations are only detectable in years where population-level productivity is high enough for the reproductive asymmetry between high and low heterozygosity individuals to become apparent. We suggest that lack of evidence of heterozygosity-fitness correlations in animal systems may be because heterozygosity is a poor proxy measure of inbreeding, especially when employing low numbers of markers, but alternatively because the asymmetries between individuals of different heterozygosities may only be apparent when environmental effects on fitness are less pronounced.
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Affiliation(s)
- Xavier A Harrison
- Centre for Ecology and Conservation, University of Exeter, Tremough Campus, Penryn, Cornwall TR10 9EZ, UK.
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