title: Genetic diversity at neutral and adaptive loci determines individual fitness in a long-lived territorial bird.
abstract: There is compelling evidence about the manifest effects of inbreeding depression on individual fitness and populations' risk of extinction. The majority of studies addressing inbreeding depression on wild populations are generally based on indirect measures of inbreeding using neutral markers. However, the study of functional loci, such as genes of the major histocompatibility complex (MHC), is highly recommended. MHC genes constitute an essential component of the immune system of individuals, which is directly related to individual fitness and survival. In this study, we analyse heterozygosity fitness correlations of neutral and adaptive genetic variation (22 microsatellite loci and two loci of the MHC class II, respectively) with the age of recruitment and breeding success of a decimated and geographically isolated population of a long-lived territorial vulture. Our results indicate a negative correlation between neutral genetic diversity and age of recruitment, suggesting that inbreeding may be delaying reproduction. We also found a positive correlation between functional (MHC) genetic diversity and breeding success, together with a specific positive effect of the most frequent pair of cosegregating MHC alleles in the population. Globally, our findings demonstrate that genetic depauperation in small populations has a negative impact on the individual fitness, thus increasing the populations' extinction risk.
authors.affiliation: Department of Conservation Biology, Doñana Biological Station (CSIC), Avda Américo Vespucio s/n, 41092 Seville, Spain. rosagudo@ebd.csic.es
authors.forename: Rosa
authors.initials: R
authors.lastname: Agudo
authors.forename: Martina
authors.initials: M
authors.lastname: Carrete
authors.forename: Miguel
authors.initials: M
authors.lastname: Alcaide
authors.forename: Ciro
authors.initials: C
authors.lastname: Rico
authors.forename: Fernando
authors.initials: F
authors.lastname: Hiraldo
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Donázar
mesh_terms: D000818:Animals; D001717:Birds / Q000235:genetics* / Q000502:physiology*; D004534:Egypt; D005260:Female; D005802:Genes, MHC Class II / Q000235:genetics*; D056084:Genetic Fitness; D005819:Genetic Markers; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population; D006579:Heterozygote; D007178:Inbreeding; D008136:Longevity / Q000235:genetics; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D013045:Species Specificity
chemical_list: D005819:Genetic Markers