title: Telomere length reveals cumulative individual and transgenerational inbreeding effects in a passerine bird.
abstract: Inbreeding results in more homozygous offspring that should suffer reduced fitness, but it can be difficult to quantify these costs for several reasons. First, inbreeding depression may vary with ecological or physiological stress and only be detectable over long time periods. Second, parental homozygosity may indirectly affect offspring fitness, thus confounding analyses that consider offspring homozygosity alone. Finally, measurement of inbreeding coefficients, survival and reproductive success may often be too crude to detect inbreeding costs in wild populations. Telomere length provides a more precise measure of somatic costs, predicts survival in many species and should reflect differences in somatic condition that result from varying ability to cope with environmental stressors. We studied relative telomere length in a wild population of Seychelles warblers (Acrocephalus sechellensis) to assess the lifelong relationship between individual homozygosity, which reflects genome-wide inbreeding in this species, and telomere length. In juveniles, individual homozygosity was negatively associated with telomere length in poor seasons. In adults, individual homozygosity was consistently negatively related to telomere length, suggesting the accumulation of inbreeding depression during life. Maternal homozygosity also negatively predicted offspring telomere length. Our results show that somatic inbreeding costs are environmentally dependent at certain life stages but may accumulate throughout life.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk NR4 7TJ, UK.
authors.forename: Kat
authors.initials: K
authors.lastname: Bebbington
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk NR4 7TJ, UK.|Department of Zoology, Edward Grey Institute, University of Oxford, Oxford OX13PS, UK.
authors.forename: Lewis G
authors.initials: LG
authors.lastname: Spurgin
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk NR4 7TJ, UK.
authors.forename: Eleanor A
authors.initials: EA
authors.lastname: Fairfield
authors.affiliation: School of Biology, The Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.|Behavioural Ecology and Physiological Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, PO Box 11103, 9700 CC, Groningen, The Netherlands.
authors.forename: Hannah L
authors.initials: HL
authors.lastname: Dugdale
authors.affiliation: Behavioural Ecology and Physiological Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, PO Box 11103, 9700 CC, Groningen, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Komdeur
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
authors.forename: Terry
authors.initials: T
authors.lastname: Burke
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk NR4 7TJ, UK.|Nature Seychelles, PO BOX 1310, Mahe, Republic of Seychelles.
authors.forename: David S
authors.initials: DS
authors.lastname: Richardson
mesh_terms: D000818:Animals; D005260:Female; D056084:Genetic Fitness; D005828:Genetics, Population; D006720:Homozygote; D007178:Inbreeding; D008297:Male; D008957:Models, Genetic; D012750:Seychelles; D020308:Songbirds / Q000235:genetics*; D016615:Telomere / Q000648:ultrastructure*
keywords: Seychelles warbler; heterozygote advantage; inbreeding; lifetime fitness; telomere; trans-generational effects