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Botero-Delgadillo E, Gilsenan C, Mueller JC, Kempenaers B. Negative effects of individual heterozygosity on reproductive success in a wild bird population. Mol Ecol 2020; 29:3196-3216. [PMID: 32668071 DOI: 10.1111/mec.15553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 07/03/2020] [Indexed: 01/01/2023]
Abstract
The evolutionary consequences of individual genetic diversity are frequently studied by assessing heterozygosity-fitness correlations (HFCs). The prevalence of positive and negative HFCs and the predominance of general versus local effects in wild populations are far from understood, partly because comprehensive studies testing for both inbreeding and outbreeding depression are lacking. We studied a genetically diverse population of blue tits in southern Germany using a genome-wide set of 87 microsatellites to investigate the relationship between proxies of reproductive success and measures of multilocus and single-locus individual heterozygosity (MLH and SLH). We used complimentary measures of MLH and partitioned markers into functional categories according to their position in the blue tit genome. HFCs based on MLH were consistently negative for functional loci, whereas correlations were rather inconsistent for loci found in nonfunctional areas of the genome. Clutch size was the only reproductive variable showing a general effect. We found evidence for local effects for three measures of reproductive success: arrival date at the breeding site, the probability of breeding at the study site and male reproductive success. For these, we observed consistent, and relatively strong, negative effects at one functional locus. Remarkably, this marker had a similar effect in another blue tit population from Austria (~400 km to the east). We suggest that a genetic local effect on timing of arrival might be responsible for most negative HFCs detected, with carry-over effects on other reproductive traits. This effect could reflect individual differences in the distance between overwintering areas and breeding sites.
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Affiliation(s)
- Esteban Botero-Delgadillo
- Department of Behavioural Ecology and Evolutionary Genetics, Max Plank Institute for Ornithology, Seewiesen, Germany
| | - Carol Gilsenan
- Department of Behavioural Ecology and Evolutionary Genetics, Max Plank Institute for Ornithology, Seewiesen, Germany
| | - Jakob C Mueller
- Department of Behavioural Ecology and Evolutionary Genetics, Max Plank Institute for Ornithology, Seewiesen, Germany
| | - Bart Kempenaers
- Department of Behavioural Ecology and Evolutionary Genetics, Max Plank Institute for Ornithology, Seewiesen, Germany
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2
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Gagnon M, Yannic G, Boyer F, Côté SD. Adult survival in migratory caribou is negatively associated with MHC functional diversity. Heredity (Edinb) 2020; 125:290-303. [PMID: 32728043 DOI: 10.1038/s41437-020-0347-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 07/04/2020] [Accepted: 07/16/2020] [Indexed: 11/09/2022] Open
Abstract
Genes of the major histocompatibility complex (MHC) are involved in acquired immunity in vertebrates. Only a few studies have investigated the fitness consequences of MHC gene diversity in wild populations. Here, we looked at the association between annual survival and body mass and MHC-DRB exon 2 (MHC-DRB) genetic diversity, obtained from high-throughput sequencing, in two declining migratory caribou (Rangifer tarandus) herds. To disentangle the potential direct and general effects of MHC-DRB genetic diversity, we compared different indices of diversity that were either based on DNA-sequence variation or on physicochemical divergence of the translated peptides, thereby covering a gradient of allelic-to-functional diversity. We found that (1) body mass was not related to MHC-DRB diversity or genotype, and (2) adult survival probability was negatively associated with point accepted mutation distance, a corrected distance that considers the likelihood of each amino acid substitution to be accepted by natural selection. In addition, we found no evidence of fluctuating selection over time on MHC-DRB diversity. We concluded that direct effects were involved in the negative relationship between MHC functional diversity and survival, although the mechanism underlying this result remains unclear. A possible explanation could be that individuals with higher MHC diversity suffer higher costs of immunity (immunopathology). Our results suggest that genetic diversity is not always beneficial even in genes that are likely to be strongly shaped by balancing selection.
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Affiliation(s)
- Marianne Gagnon
- Département de Biologie, Caribou Ungava and Centre d'Études Nordiques, Université Laval, 1045 avenue de la Médecine, Quebec City, QC, G1V 0A6, Canada
| | - Glenn Yannic
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, LECA, 38000, Grenoble, France.
| | - Frédéric Boyer
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, LECA, 38000, Grenoble, France
| | - Steeve D Côté
- Département de Biologie, Caribou Ungava and Centre d'Études Nordiques, Université Laval, 1045 avenue de la Médecine, Quebec City, QC, G1V 0A6, Canada
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3
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Hasselgren M, Angerbjörn A, Eide NE, Erlandsson R, Flagstad Ø, Landa A, Wallén J, Norén K. Genetic rescue in an inbred Arctic fox ( Vulpes lagopus) population. Proc Biol Sci 2019; 285:rspb.2017.2814. [PMID: 29593110 DOI: 10.1098/rspb.2017.2814] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/02/2018] [Indexed: 12/22/2022] Open
Abstract
Isolation of small populations can reduce fitness through inbreeding depression and impede population growth. Outcrossing with only a few unrelated individuals can increase demographic and genetic viability substantially, but few studies have documented such genetic rescue in natural mammal populations. We investigate the effects of immigration in a subpopulation of the endangered Scandinavian arctic fox (Vulpes lagopus), founded by six individuals and isolated for 9 years at an extremely small population size. Based on a long-term pedigree (105 litters, 543 individuals) combined with individual fitness traits, we found evidence for genetic rescue. Natural immigration and gene flow of three outbred males in 2010 resulted in a reduction in population average inbreeding coefficient (f), from 0.14 to 0.08 within 5 years. Genetic rescue was further supported by 1.9 times higher juvenile survival and 1.3 times higher breeding success in immigrant first-generation offspring compared with inbred offspring. Five years after immigration, the population had more than doubled in size and allelic richness increased by 41%. This is one of few studies that has documented genetic rescue in a natural mammal population suffering from inbreeding depression and contributes to a growing body of data demonstrating the vital connection between genetics and individual fitness.
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Affiliation(s)
- Malin Hasselgren
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| | - Anders Angerbjörn
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| | - Nina E Eide
- Norwegian Institute for Nature Research, 7485 Trondheim, Norway
| | - Rasmus Erlandsson
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| | | | - Arild Landa
- Norwegian Institute for Nature Research, 7485 Trondheim, Norway
| | - Johan Wallén
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
| | - Karin Norén
- Department of Zoology, Stockholm University, 10691 Stockholm, Sweden
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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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Heterozygosity–fitness correlations in blue tit nestlings (Cyanistis caeruleus) under contrasting rearing conditions. Evol Ecol 2017. [DOI: 10.1007/s10682-017-9911-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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6
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Stoffel MA, Esser M, Kardos M, Humble E, Nichols H, David P, Hoffman JI. inbreedR: an
R
package for the analysis of inbreeding based on genetic markers. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12588] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Martin A. Stoffel
- Department of Animal Behaviour Bielefeld University Box 100131 Bielefeld Germany
- Faculty of Science School of Natural Sciences and Psychology Liverpool John Moores University Liverpool L3 3AF UK
| | - Mareike Esser
- Faculty of Technology Bielefeld University Box 100131 Bielefeld Germany
| | - Marty Kardos
- Department of Evolutionary Biology Evolutionary Biology Centre (EBC) Uppsala University Norbyvagen 18D Uppsala 75236 Sweden
| | - Emily Humble
- Department of Animal Behaviour Bielefeld University Box 100131 Bielefeld Germany
- British Antarctic Survey High Cross, Madingley Road Cambridge CB3 OET UK
| | - Hazel Nichols
- Faculty of Science School of Natural Sciences and Psychology Liverpool John Moores University Liverpool L3 3AF UK
| | - Patrice David
- Centre d'Ecologie Fonctionnelle et Evolutive Centre National de la Recherche Scientifique 34293 Montpellier France
| | - Joseph I. Hoffman
- Department of Animal Behaviour Bielefeld University Box 100131 Bielefeld Germany
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7
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Menzel M, Sletvold N, Ågren J, Hansson B. Inbreeding Affects Gene Expression Differently in Two Self-Incompatible Arabidopsis lyrata Populations with Similar Levels of Inbreeding Depression. Mol Biol Evol 2015; 32:2036-47. [PMID: 25855783 PMCID: PMC4833072 DOI: 10.1093/molbev/msv086] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Knowledge of which genes and pathways are affected by inbreeding may help understanding the genetic basis of inbreeding depression, the potential for purging (selection against deleterious recessive alleles), and the transition from outcrossing to selfing. Arabidopsis lyrata is a predominantly self-incompatible perennial plant, closely related to the selfing model species A. thaliana. To examine how inbreeding affects gene expression, we compared the transcriptome of experimentally selfed and outcrossed A. lyrata originating from two Scandinavian populations that express similar inbreeding depression for fitness (∂ ≈ 0.80). The number of genes significantly differentially expressed between selfed and outcrossed individuals were 2.5 times higher in the Norwegian population (≈ 500 genes) than in the Swedish population (≈ 200 genes). In both populations, a majority of genes were upregulated on selfing (≈ 80%). Functional annotation analysis of the differentially expressed genes showed that selfed offspring were characterized by 1) upregulation of stress-related genes in both populations and 2) upregulation of photosynthesis-related genes in Sweden but downregulation in Norway. Moreover, we found that reproduction- and pollination-related genes were affected by inbreeding only in Norway. We conclude that inbreeding causes both general and population-specific effects. The observed common effects suggest that inbreeding generally upregulates rather than downregulates gene expression and affects genes associated with stress response and general metabolic activity. Population differences in the number of affected genes and in effects on the expression of photosynthesis-related genes show that the genetic basis of inbreeding depression can differ between populations with very similar levels of inbreeding depression.
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Affiliation(s)
- Mandy Menzel
- Molecular Ecology and Evolution Laboratory, Department of Biology, Lund University, Lund, Sweden Unit of Respiratory Immunopharmacology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Nina Sletvold
- Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Jon Ågren
- Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Bengt Hansson
- Molecular Ecology and Evolution Laboratory, Department of Biology, Lund University, Lund, Sweden
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8
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Ferrer ES, García-Navas V, Bueno-Enciso J, Sanz JJ, Ortego J. Multiple sexual ornaments signal heterozygosity in male blue tits. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12513] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Esperanza S. Ferrer
- Departamento de Ciencias Ambientales; Facultad de Ciencias Ambientales y Bioquímica; Universidad de Castilla-La Mancha; Avda. Carlos III s/n 45071 Toledo Spain
- Grupo de Investigación de la Biodiversidad Genética y Cultural; Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM); Ronda de Toledo s/n 13071 Ciudad Real Spain
| | - Vicente García-Navas
- Departamento de Ciencias Ambientales; Facultad de Ciencias Ambientales y Bioquímica; Universidad de Castilla-La Mancha; Avda. Carlos III s/n 45071 Toledo Spain
- Grupo de Investigación de la Biodiversidad Genética y Cultural; Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM); Ronda de Toledo s/n 13071 Ciudad Real Spain
- Evolution and Genetics of Love, Life and Death Group; Institute of Evolutionary Biology and Environmental Studies; University of Zurich; Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Javier Bueno-Enciso
- Departamento de Ciencias Ambientales; Facultad de Ciencias Ambientales y Bioquímica; Universidad de Castilla-La Mancha; Avda. Carlos III s/n 45071 Toledo Spain
| | - Juan José Sanz
- Departamento de Ecología Evolutiva; Museo Nacional de Ciencias Naturales (CSIC); C/ José Gutiérrez Abascal 2 28006 Madrid Spain
| | - Joaquín Ortego
- Conservation and Evolutionary Genetics Group; Department of Integrative Ecology; Estación Biológica de Doñana (EBD-CSIC); Avda. Américo Vespucio s/n 41092 Seville Spain
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9
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High-throughput sequencing reveals inbreeding depression in a natural population. Proc Natl Acad Sci U S A 2014; 111:3775-80. [PMID: 24586051 DOI: 10.1073/pnas.1318945111] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Proxy measures of genome-wide heterozygosity based on approximately 10 microsatellites have been used to uncover heterozygosity fitness correlations (HFCs) for a wealth of important fitness traits in natural populations. However, effect sizes are typically very small and the underlying mechanisms remain contentious, as a handful of markers usually provides little power to detect inbreeding. We therefore used restriction site associated DNA (RAD) sequencing to accurately estimate genome-wide heterozygosity, an approach transferrable to any organism. As a proof of concept, we first RAD sequenced oldfield mice (Peromyscus polionotus) from a known pedigree, finding strong concordance between the inbreeding coefficient and heterozygosity measured at 13,198 single-nucleotide polymorphisms (SNPs). When applied to a natural population of harbor seals (Phoca vitulina), a weak HFC for parasite infection based on 27 microsatellites strengthened considerably with 14,585 SNPs, the deviance explained by heterozygosity increasing almost fivefold to a remarkable 49%. These findings arguably provide the strongest evidence to date of an HFC being due to inbreeding depression in a natural population lacking a pedigree. They also suggest that under some circumstances heterozygosity may explain far more variation in fitness than previously envisaged.
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10
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Chudzińska E, Diatta JB, Wojnicka-Półtorak A. Adaptation strategies and referencing trial of Scots and black pine populations subjected to heavy metal pollution. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:2165-2177. [PMID: 24043503 PMCID: PMC3906555 DOI: 10.1007/s11356-013-2081-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 08/16/2013] [Indexed: 05/02/2023]
Abstract
The impact of industrial heavy metal pollution on Scots pine (Pinus sylvestris L.) and black pine (Pinus nigra Arn.) populations was investigated. Sampled pine stands, which were located in Upper Silesia (southern Poland) in an area strongly polluted by heavy metals, consisted of resistant and sensitive trees. To evaluate the adaptation process, genetic structure and diversity was tested using isozyme analysis. Higher levels of Zn, Pb, Cd and Cu were detected in needles of sensitive trees compared with resistant ones. With respect to morphology, Scots pines were more distinctly impaired than black pines. Although black pines had lower heavy metal concentrations, levels in 1-year-old needles, other than Cu, significantly exceeded "reference plant" values (Markert 1994). In both species, resistant trees demonstrated a lower degree of genetic variation than metal-sensitive trees with respect to some enzyme loci (SHDH A, PGI, PGM, MDH C and DIA). This observation was corroborated in sensitive trees by the smaller number of identified alleles and alleles per locus, absence of private alleles and significant excess of homozygotes in relation to expected Hardy-Weinberg equilibrium values. Assuming that only resistant trees of both species survive under conditions of prolonged soil contamination, the observed genetic structure implies that remaining populations will be depleted of some alleles of unknown adaptive value to future selection pressures. Genetic changes induced by heavy metals suggest an important role for specific enzymes-FEST, SHDH A and B, GOT B and PGI-in the adaptation process. Our results may serve as a basis for selection and propagation of individuals appropriate for re-cultivation of areas chemically degraded by industrial activity.
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Affiliation(s)
- Ewa Chudzińska
- Institute of Experimental Biology, Department of Genetics, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznań, Poland
| | - Jean B. Diatta
- Department of Agricultural Chemistry and Environmental Biogeochemistry, Poznan University of Life Sciences, ul. Wojska Polskiego 71F, 60-625 Poznań, Poland
| | - Aleksandra Wojnicka-Półtorak
- Institute of Experimental Biology, Department of Genetics, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznań, Poland
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11
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Løvlie H, Gillingham MAF, Worley K, Pizzari T, Richardson DS. Cryptic female choice favours sperm from major histocompatibility complex-dissimilar males. Proc Biol Sci 2013; 280:20131296. [PMID: 24004935 PMCID: PMC3768299 DOI: 10.1098/rspb.2013.1296] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cryptic female choice may enable polyandrous females to avoid inbreeding or bias offspring variability at key loci after mating. However, the role of these genetic benefits in cryptic female choice remains poorly understood. Female red junglefowl, Gallus gallus, bias sperm use in favour of unrelated males. Here, we experimentally investigate whether this bias is driven by relatedness per se, or by similarity at the major histocompatibility complex (MHC), genes central to vertebrate acquired immunity, where polymorphism is critical to an individual's ability to combat pathogens. Through experimentally controlled natural matings, we confirm that selection against related males' sperm occurs within the female reproductive tract but demonstrate that this is more accurately predicted by MHC similarity: controlling for relatedness per se, more sperm reached the eggs when partners were MHC-dissimilar. Importantly, this effect appeared largely owing to similarity at a single MHC locus (class I minor). Further, the effect of MHC similarity was lost following artificial insemination, suggesting that male phenotypic cues might be required for females to select sperm differentially. These results indicate that postmating mechanisms that reduce inbreeding may do so as a consequence of more specific strategies of cryptic female choice promoting MHC diversity in offspring.
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Affiliation(s)
- Hanne Løvlie
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford OX1 3PS, UK.
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12
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Boerner M, Hoffman JI, Amos W, Chakarov N, Kruger O. No correlation between multi-locus heterozygosity and fitness in the common buzzard despite heterozygote advantage for plumage colour. J Evol Biol 2013; 26:2233-43. [PMID: 23980596 DOI: 10.1111/jeb.12221] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 06/18/2013] [Accepted: 06/28/2013] [Indexed: 10/26/2022]
Abstract
Correlations between heterozygosity and fitness are frequently found but rarely well understood. Fitness can be affected by single loci of large effect which correlate with neutral markers via linkage disequilibrium, or as a result of variation in genome-wide heterozygosity following inbreeding. We explored these alternatives in the common buzzard, a raptor species in which three colour morphs differ in their lifetime reproductive success. Using 18 polymorphic microsatellite loci, we evaluated potential genetic differences among the morphs which may lead to subpopulation structuring and tested for correlations between three fitness-related traits and heterozygosity, both genome wide and at each locus separately. Despite their assortative mating pattern, the buzzard morphs were found to be genetically undifferentiated. Multilocus heterozygosity was only found to be correlated with a single fitness-related trait, infection with the blood parasite, Leucocytozoon buteonis, and this was via interactions with vole abundance and age. One locus also showed a significant relationship with blood parasite infection and ectoparasite infestation. The vicinity of this locus contains two genes, one of which is potentially implicated in the immune system of birds. We conclude that genome-wide heterozygosity is unlikely to be a major determinant of parasite burden and body condition in the polymorphic common buzzard.
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Affiliation(s)
- M Boerner
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
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13
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Townsend SM, Jamieson IG. INBREEDING INFLUENCES WITHIN-BROOD HETEROZYGOSITY-FITNESS CORRELATIONS (HFCS) IN AN ISOLATED PASSERINE POPULATION. Evolution 2013; 67:2299-308. [DOI: 10.1111/evo.12113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 02/25/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Sheena M. Townsend
- Allan Wilson Centre for Molecular Ecology and Evolution; Department of Zoology; University of Otago; 340 Great King Street Dunedin 9054 New Zealand
| | - Ian G. Jamieson
- Allan Wilson Centre for Molecular Ecology and Evolution; Department of Zoology; University of Otago; 340 Great King Street Dunedin 9054 New Zealand
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14
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Laine VN, Herczeg G, Shikano T, Primmer CR. Heterozygosity-behaviour correlations in nine-spined stickleback (Pungitius pungitius) populations: contrasting effects at random and functional loci. Mol Ecol 2012; 21:4872-84. [DOI: 10.1111/j.1365-294x.2012.05741.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 06/18/2012] [Accepted: 06/20/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Veronika N. Laine
- Division of Genetics and Physiology, Department of Biology; University of Turku; Turku; FI-20014; Finland
| | - Gábor Herczeg
- Ecological Genetics Research Unit, Department of Biosciences; University of Helsinki; PO Box 65; Helsinki; FI-00014; Finland
| | - Takahito Shikano
- Ecological Genetics Research Unit, Department of Biosciences; University of Helsinki; PO Box 65; Helsinki; FI-00014; Finland
| | - Craig R. Primmer
- Division of Genetics and Physiology, Department of Biology; University of Turku; Turku; FI-20014; Finland
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15
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González-Varo JP, Aparicio A, Lavergne S, Arroyo J, Albaladejo RG. Contrasting heterozygosity-fitness correlations between populations of a self-compatible shrub in a fragmented landscape. Genetica 2012; 140:31-8. [DOI: 10.1007/s10709-012-9655-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 04/16/2012] [Indexed: 10/28/2022]
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16
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Fickel J, Bubliy OA, Stache A, Noventa T, Jirsa A, Heurich M. Crossing the border? Structure of the red deer (Cervus elaphus) population from the Bavarian–Bohemian forest ecosystem. Mamm Biol 2012. [DOI: 10.1016/j.mambio.2011.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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17
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Borrell YJ, Carleos CE, Sánchez JA, Vázquez E, Gallego V, Asturiano JF, Blanco G. Heterozygosity-fitness correlations in the gilthead sea bream Sparus aurata using microsatellite loci from unknown and gene-rich genomic locations. JOURNAL OF FISH BIOLOGY 2011; 79:1111-1129. [PMID: 22026596 DOI: 10.1111/j.1095-8649.2011.03099.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Heterozygosity-fitness correlations (HFC) were assessed for a sample of a gilthead sea bream Sparus aurata population. Two hundred and seventy-one fish were genotyped at 22 known and novel microsatellite loci, from which correlations between the multilocus heterozygosity index (I(MLH) ) and various fitness traits (fork length, mass and specific growth rates) were calculated. Significant global HFCs were found in this sample (0·02 ≤r(2) ≤ 0·08). In addition, all the significant correlations found in this work were negative, indicating that heterozygotes had lower fitness than their homozygote counterparts. Marker location could not explain the observed HFCs. Evidence of inbreeding, outbreeding or population and family structuring was not found in this work. The presence of undetected general effects that may lead to the appearance of HFCs, however, cannot be ruled out. These results seem to be best explained by the occurrence of local effects (due to linkage) or even by possible direct locus advantages.
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Affiliation(s)
- Y J Borrell
- Laboratorio de Genética Acuícola, Departamento de Biología Funcional, Universidad de Oviedo, IUBA, 33071 Oviedo, Spain
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Del Castillo RF, Trujillo-Argueta S, Sánchez-Vargas N, Newton AC. Genetic factors associated with population size may increase extinction risks and decrease colonization potential in a keystone tropical pine. Evol Appl 2011; 4:574-88. [PMID: 25568006 PMCID: PMC3352421 DOI: 10.1111/j.1752-4571.2010.00177.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 11/14/2010] [Indexed: 12/03/2022] Open
Abstract
Pioneer species are essential for forest regeneration and ecosystem resilience. Pinus chiapensis is an endangered pioneer key species for tropical montane cloud forest regeneration in Mesoamerica. Human activities have severely reduced some P. chiapensis populations, which exhibited a small or null colonization potential suggesting the involvement of genetic factors associated with small populations. We explored the relationships between (i) population genetic diversity (allozymes) and population size, including sampling size effects, (ii) fitness estimates associated with colonization potential (seed viability and seedling performance) in a common environment and population size, and (iii) fitness estimates and observed heterozygosity in populations with sizes spanning five orders of magnitude. All the estimates of genetic diversity and fitness increased significantly with population size. Low fitness was detected in progenies of small populations of disturbed and undisturbed habitats. Progenies with the lowest observed heterozygosity displayed the lowest fitness estimates, which, in turn, increased with heterozygosity, but seed viability peaked at intermediate heterozygosity values suggesting inbreeding and outbreeding depression. Inbreeding depression appears to be the most immediate genetic factor in population decline. Conservation efforts should try to maintain large and genetically diverse populations, enhance gene flow by restoring connectivity between adjacent populations, and avoid genetically distant individuals.
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Affiliation(s)
- Rafael F Del Castillo
- Instituto Politécnico Nacional CIIDIR Oaxaca, Hornos, Santa Cruz Xoxocotlán; Oaxaca, Mexico
| | - Sonia Trujillo-Argueta
- Instituto Politécnico Nacional CIIDIR Oaxaca, Hornos, Santa Cruz Xoxocotlán; Oaxaca, Mexico
| | - Nahúm Sánchez-Vargas
- Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana de San Nicolás de Hidalgo, (IIAF-UMSNH) Morelia-Zinapécuaro, Tarímbaro, Michoacán, México
| | - Adrian C Newton
- School of Conservation Sciences, Bournemouth University Talbot Campus, Fern Barrow, Poole, Dorset, UK
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OLANO-MARIN JUANITA, MUELLER JAKOBC, KEMPENAERS BART. Heterozygosity and survival in blue tits (Cyanistes caeruleus): contrasting effects of presumably functional and neutral loci. Mol Ecol 2011; 20:4028-41. [DOI: 10.1111/j.1365-294x.2011.05177.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Vitikainen E, Haag-Liautard C, Sundström L. INBREEDING AND REPRODUCTIVE INVESTMENT IN THE ANT FORMICA EXSECTA. Evolution 2011; 65:2026-37. [DOI: 10.1111/j.1558-5646.2011.01273.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Luquet E, David P, Lena JP, Joly P, Konecny L, Dufresnes C, Perrin N, Plenet S. Heterozygosity-fitness correlations among wild populations of European tree frog (Hyla arborea) detect fixation load. Mol Ecol 2011; 20:1877-87. [PMID: 21410805 DOI: 10.1111/j.1365-294x.2011.05061.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Quantifying the impacts of inbreeding and genetic drift on fitness traits in fragmented populations is becoming a major goal in conservation biology. Such impacts occur at different levels and involve different sets of loci. Genetic drift randomly fixes slightly deleterious alleles leading to different fixation load among populations. By contrast, inbreeding depression arises from highly deleterious alleles in segregation within a population and creates variation among individuals. A popular approach is to measure correlations between molecular variation and phenotypic performances. This approach has been mainly used at the individual level to detect inbreeding depression within populations and sometimes at the population level but without consideration about the genetic processes measured. For the first time, we used in this study a molecular approach considering both the interpopulation and intrapopulation level to discriminate the relative importance of inbreeding depression vs. fixation load in isolated and non-fragmented populations of European tree frog (Hyla arborea), complemented with interpopulational crosses. We demonstrated that the positive correlations observed between genetic heterozygosity and larval performances on merged data were mainly caused by co-variations in genetic diversity and fixation load among populations rather than by inbreeding depression and segregating deleterious alleles within populations. Such a method is highly relevant in a conservation perspective because, depending on how populations lose fitness (inbreeding vs. fixation load), specific management actions may be designed to improve the persistence of populations.
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Affiliation(s)
- E Luquet
- Université Lyon 1, CNRS UMR 5023 Ecologie des Hydrosystèmes Fluviaux, Université Claude Bernard Lyon 1, Université de Lyon, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
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22
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Gompper ME, Monello RJ, Eggert LS. Genetic variability and viral seroconversion in an outcrossing vertebrate population. Proc Biol Sci 2011; 278:204-10. [PMID: 20667873 PMCID: PMC3013388 DOI: 10.1098/rspb.2010.1113] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 07/08/2010] [Indexed: 11/12/2022] Open
Abstract
Inverse correlations between genetic variability and parasitism are important concerns for conservation biologists. We examined correlations between neutral genetic variability and the presence of antibodies to canine distemper virus (CDV) and feline parvovirus (FPV) in a free-ranging population of raccoons. Over 3 years there was a strong relationship between age and seroprevalence rates. Most young animals were seronegative to CDV and FPV, but the oldest age class was greater than 80 per cent seropositive to both viruses. CDV-seropositive animals had greater heterozygosity and lower measures of inbreeding compared with CDV-seronegative animals. This relationship was strongest among the youngest animals and did not occur during a 1 year CDV epidemic. In contrast, FPV-seropositive animals only had significantly lower measures of inbreeding in 1 year, perhaps because FPV-associated mortality is relatively low or primarily occurs among very young individuals that were under-represented in our sampling. These results suggest that even in large outcrossing populations, animals with lower heterozygosity and higher measures of inbreeding are less likely to successfully mount an immune response when challenged by highly pathogenic parasites.
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Affiliation(s)
- Matthew E Gompper
- Department of Fisheries and Wildlife Sciences, University of Missouri, , Columbia, MO 65211, USA.
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Chaves LJ, Vencovsky R, Silva RSM, de Campos Telles MP, Zucchi MI, Coelho ASG. Estimating inbreeding depression in natural plant populations using quantitative and molecular data. CONSERV GENET 2010. [DOI: 10.1007/s10592-010-0164-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Grueber CE, Waters JM, Jamieson IG. The imprecision of heterozygosity-fitness correlations hinders the detection of inbreeding and inbreeding depression in a threatened species. Mol Ecol 2010; 20:67-79. [PMID: 21087447 DOI: 10.1111/j.1365-294x.2010.04930.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In nonpedigreed wild populations, inbreeding depression is often quantified through the use of heterozygosity-fitness correlations (HFCs), based on molecular estimates of relatedness. Although such correlations are typically interpreted as evidence of inbreeding depression, by assuming that the marker heterozygosity is a proxy for genome-wide heterozygosity, theory predicts that these relationships should be difficult to detect. Until now, the vast majority of empirical research in this area has been performed on generally outbred, nonbottlenecked populations, but differences in population genetic processes may limit extrapolation of results to threatened populations. Here, we present an analysis of HFCs, and their implications for the interpretation of inbreeding, in a free-ranging pedigreed population of a bottlenecked species: the endangered takahe (Porphyrio hochstetteri). Pedigree-based inbreeding depression has already been detected in this species. Using 23 microsatellite loci, we observed only weak evidence of the expected relationship between multilocus heterozygosity and fitness at individual life-history stages (such as survival to hatching and fledging), and parameter estimates were imprecise (had high error). Furthermore, our molecular data set could not accurately predict the inbreeding status of individuals (as 'inbred' or 'outbred', determined from pedigrees), nor could we show that the observed HFCs were the result of genome-wide identity disequilibrium. These results may be attributed to high variance in heterozygosity within inbreeding classes. This study is an empirical example from a free-ranging endangered species, suggesting that even relatively large numbers (>20) of microsatellites may give poor precision for estimating individual genome-wide heterozygosity. We argue that pedigree methods remain the most effective method of quantifying inbreeding in wild populations, particularly those that have gone through severe bottlenecks.
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KÜPPER CLEMENS, KOSZTOLÁNYI ANDRÁS, AUGUSTIN JAKOB, DAWSON DEBORAHA, BURKE TERRY, SZÉKELY TAMÁS. Heterozygosity-fitness correlations of conserved microsatellite markers in Kentish plovers Charadrius alexandrinus. Mol Ecol 2010; 19:5172-85. [DOI: 10.1111/j.1365-294x.2010.04867.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Spiering PA, Szykman Gunther M, Somers MJ, Wildt DE, Walters M, Wilson AS, Maldonado JE. Inbreeding, heterozygosity and fitness in a reintroduced population of endangered African wild dogs (Lycaon pictus). CONSERV GENET 2010. [DOI: 10.1007/s10592-010-0147-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Taylor SS, Sardell RJ, Reid JM, Bucher T, Taylor NG, Arcese P, Keller LF. Inbreeding coefficient and heterozygosity-fitness correlations in unhatched and hatched song sparrow nestmates. Mol Ecol 2010; 19:4454-61. [PMID: 20854411 DOI: 10.1111/j.1365-294x.2010.04824.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heterozygosity-fitness correlations use molecular measures of heterozygosity as proxy estimates of individual inbreeding coefficients (f) to examine relationships between inbreeding and fitness traits. Heterozygosity-fitness correlations partly depend on the assumption that individual heterozygosity and f are strongly and negatively correlated. Although theory predicts that this relationship will be strongest when mean f and variance in f are high, few studies of heterozygosity-fitness correlations include estimates of f based on pedigrees, which allow for more thorough examinations of the relationship between f, heterozygosity and fitness in nature. We examined relationships between pedigree-based estimates of f, multilocus heterozygosity (MLH) and the probability of survival to hatch in song sparrow nestmates. f and MLH were weakly, but significantly negatively correlated. Inbreeding coefficient predicted the probability of survival to hatch. In contrast, MLH did not predict the probability of survival to hatch nor did it account for residual variation in survival to hatch after statistically controlling for the effects of f. These results are consistent with the expectation that heterozygosity-f correlations will be weak when mean and variance in f are low. Our results also provide empirical support for recent simulation studies, which show that variation in MLH among siblings with equal f can be large and may obscure MLH-fitness relationships.
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Affiliation(s)
- Sabrina S Taylor
- School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803, USA.
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28
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Townsend AK, Clark AB, McGowan KJ, Miller AD, Buckles EL. Condition, innate immunity and disease mortality of inbred crows. Proc Biol Sci 2010; 277:2875-83. [PMID: 20444716 DOI: 10.1098/rspb.2010.0480] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cooperatively breeding American crows (Corvus brachyrhynchos) suffer a severe disease-mediated survival cost from inbreeding, but the proximate mechanisms linking inbreeding to disease are unknown. Here, we examine indices of nestling body condition and innate immunocompetence in relationship to inbreeding and disease mortality. Using an estimate of microsatellite heterozygosity that predicts inbreeding in this population, we show that inbred crows were in relatively poor condition as nestlings, and that body condition index measured in the first 2-33 days after hatching, in addition to inbreeding index, predicted disease probability in the first 34 months of life. Inbred nestlings also mounted a weaker response along one axis of innate immunity: the proportion of bacteria killed in a microbiocidal assay increased as heterozygosity index increased. Relatively poor body condition and low innate immunocompetence are two mechanisms that might predispose inbred crows to ultimate disease mortality. A better understanding of condition-mediated inbreeding depression can guide efforts to minimize disease costs of inbreeding in small populations.
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Affiliation(s)
- Andrea K Townsend
- Fuller Evolutionary Biology Program, Cornell Laboratory of Ornithology, , 159 Sapsucker Woods Road, Ithaca, NY 14850, USA.
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29
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Linking genetic mechanisms of heterozygosity-fitness correlations to footprints of selection at single loci. Evol Ecol 2010. [DOI: 10.1007/s10682-010-9377-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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30
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HANSSON BENGT. The use (or misuse) of microsatellite allelic distances in the context of inbreeding and conservation genetics. Mol Ecol 2010; 19:1082-90. [DOI: 10.1111/j.1365-294x.2010.04556.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Abstract
Owing to the remarkable progress of molecular techniques, heterozygosity-fitness correlations (HFCs) have become a popular tool to study the impact of inbreeding in natural populations. However, their underlying mechanisms are often hotly debated. Here we argue that these "debates" rely on verbal arguments with no basis in existing theory and inappropriate statistical testing, and that it is time to reconcile HFC with its historical and theoretical fundaments. We show that available data are quantitatively and qualitatively consistent with inbreeding-based theory. HFC can be used to estimate the impact of inbreeding in populations, although such estimates are bound to be imprecise, especially when inbreeding is weak. Contrary to common belief, linkage disequilibrium is not an alternative to inbreeding, but rather comes with some forms of inbreeding, and is not restricted to closely linked loci. Finally, the contribution of local chromosomal effects to HFC, while predicted by inbreeding theory, is expected to be small, and has rarely if ever proven statistically significant using adequate tests. We provide guidelines to safely interpret and quantify HFCs, and present how HFCs can be used to quantify inbreeding load and unravel the structure of natural populations.
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Affiliation(s)
- Marta Szulkin
- Department of Zoology, Edward Grey Institute, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
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33
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Banks SC, Dubach J, Viggers KL, Lindenmayer DB. Adult survival and microsatellite diversity in possums: effects of major histocompatibility complex-linked microsatellite diversity but not multilocus inbreeding estimators. Oecologia 2009; 162:359-70. [PMID: 19830457 DOI: 10.1007/s00442-009-1464-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 08/27/2009] [Indexed: 10/20/2022]
Abstract
Adult survival is perhaps the fitness parameter most important to population growth in long-lived species. Intrinsic and extrinsic covariates of survival are therefore likely to be important drivers of population dynamics. We used long-term mark-recapture data to identify genetic, individual and environmental covariates of local survival in a natural population of mountain brushtail possums (Trichosurus cunninghami). Rainfall and intra-individual diversity at microsatellite DNA markers were associated with increased local survival of adults and juveniles. We contrasted the performance of several microsatellite heterozygosity measures, including internal relatedness (IR), homozygosity by loci (HL) and the mean multilocus estimate of the squared difference in microsatellite allele sizes within an individual (mean d (2)). However, the strongest effect on survival was not associated with multilocus microsatellite diversity (which would indicate a genome-wide inbreeding effect), but a subset of two loci. This included a major histocompatibility complex (MHC)-linked marker and a putatively neutral microsatellite locus. For both loci, diversity measures incorporating allele size information had stronger associations with survival than measures based on heterozygosity, whether or not allele frequency information was included (such as IR). Increased survival was apparent among heterozygotes at the MHC-linked locus, but the benefits of heterozygosity to survival were reduced in heterozygotes with larger differences in allele size. The effect of heterozygosity on fitness-related traits was supported by data on endoparasites in a subset of the individuals studied in this population. There was no apparent density dependence in survival, nor an effect of sex, age or immigrant status. Our findings suggest that in the apparent absence of inbreeding, variation at specific loci can generate strong associations between fitness and diversity at linked markers.
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Affiliation(s)
- Sam C Banks
- The Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 0200, Australia.
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Fossøy F, Johnsen A, Lifjeld JT. Cell-mediated immunity and multi-locus heterozygosity in bluethroat nestlings. J Evol Biol 2009; 22:1954-60. [PMID: 19583700 DOI: 10.1111/j.1420-9101.2009.01790.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent evidence suggests that marker-based heterozygosity-fitness correlations may be driven by only one or a few markers, indicating local heterozygosity effects caused by linkage disequilibrium with functional genes. In this study, we investigated the relationship between microsatellite heterozygosity and a measure of cell-mediated immunity (phytohaemagglutinin; PHA) in bluethroat (Luscinia s. svecica) nestlings using a full-sibling design. We found significant positive associations between PHA response and two different indices of microsatellite heterozygosity, i.e. multi-locus heterozygosity and mean d(2). However, model comparisons disclosed that both associations were more likely caused by local effects rather than general effects and that the two local effects appeared to be realized through two different genetic mechanisms. Our results indicate that both the random assortment of parental chromosomes during meiosis as well as inbreeding can drive heterozygosity-fitness correlations.
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Affiliation(s)
- F Fossøy
- National Centre for Biosystematics, Natural History Museum, University of Oslo, Oslo, Norway.
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35
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Chapman JR, Nakagawa S, Coltman DW, Slate J, Sheldon BC. A quantitative review of heterozygosity-fitness correlations in animal populations. Mol Ecol 2009; 18:2746-65. [PMID: 19500255 DOI: 10.1111/j.1365-294x.2009.04247.x] [Citation(s) in RCA: 301] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J R Chapman
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
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Govindaraju DR, Larson MG, Yin X, Benjamin EJ, Rao MB, Vasan RS. Association between SNP heterozygosity and quantitative traits in the Framingham Heart Study. Ann Hum Genet 2009; 73:465-73. [PMID: 19523151 PMCID: PMC3760672 DOI: 10.1111/j.1469-1809.2009.00514.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Associations between multilocus heterozygosity and fitness traits, also termed heterozygosity and fitness correlations (HFCs), have been reported in numerous organisms. These studies, in general, indicate a positive relationship between heterozygosity and fitness traits. We studied the association between genome-wide heterozygosity at 706 non-synonymous and synonymous SNPs and 19 quantitative traits, including morphological, biochemical and fitness traits in the Framingham Heart Study. Statistically significant association was found between heterozygosity and systolic and diastolic blood pressures as well as left ventricular diameter and wall thickness. These results suggest that heterozygosity may be associated with traits, such as blood pressure that closely track environmental variations. Balancing selection may be operating in the maintenance of heterozygosity and the major components of blood pressure and hypertension. Genome wide SNP heterozygosity may be used to understand the phenomenon of dominance as well as the evolutionary basis of many quantitative traits in humans.
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Abstract
Although the application of population and evolutionary genetic theory and methods to address issues of conservation relevance has a long history, the formalization of conservation genetics as a research field is still relatively recent. One of the periodic catalysts for increased research effort in the field has been advances in molecular technologies, leading to an increasingly wider variety of molecular markers for application in conservation genetic studies. To date, genetic methods have been applied in conservation biology primarily as selectively neutral molecular tools for resolving questions of conservation relevance. However, there has been renewed interest in complementing the analysis of neutral markers with the assessment of loci that may be directly involved in responses to processes such as environmental change, with a view to identifying the genes involved in them. These kinds of studies are now possible due to the increase in availability of genomic resources for nonmodel organisms, and there will likely be an even more rapid increase in the near future due to the advent of new ultrahigh throughput-sequencing technologies. This review considers the implications of the most recent developments in genomic technologies and their potential for contributing to the conservation of populations and species. Three "conservation genomics" case studies are presented (Atlantic salmon, Salmo sala; the butterfly, Melitaea cinxia; and the California condor, Gymnogyps californianus) in order to demonstrate the diversity of applications now possible. While it is clear that genomics approaches in conservation will not replace other tried-and-true methods, these recent developments open up an exciting new range of possibilities that will enable further diversification of the application of genomics in conservation biology.
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Affiliation(s)
- Craig R Primmer
- Division of Genetics and Physiology, Department of Biology, University of Turku, Turku, Finland.
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GRUEBER CATHERINEE, WALLIS GRAHAMP, JAMIESON IANG. Heterozygosity-fitness correlations and their relevance to studies on inbreeding depression in threatened species. Mol Ecol 2008; 17:3978-84. [DOI: 10.1111/j.1365-294x.2008.03910.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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