Context-dependent associations between heterozygosity and immune variation in a wild carnivore

BMC Evolutionary Biology

Research Article

Marilyn Cruz¹  Patrick M. Brock²  Simon J. Goodman³  Ailsa J. Hall⁴  Karina Acevedo-Whitehouse⁵ 

[1] Galapagos Genetics, Epidemiology and Pathology Laboratory, Galapagos National Park & University of Guayaquil, Puerto Ayora, Galapagos Islands, Ecuador;Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, G61 1QH, Glasgow, UK;Zoological Society of London, Regent’s Park, NW1 4RY, London, UK;School of Biology, University of Leeds, LS2 9JT, Leeds, UK;School of Biology, University of Leeds, LS2 9JT, Leeds, UK;Sea Mammal Research Unit, Scottish Ocean Institute, University of St. Andrews, KY16 8LB, Fife, UK;Zoological Society of London, Regent’s Park, NW1 4RY, London, UK;Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, 76230, Queretaro, Mexico;

关键词: Genetics;    Microsatellite;    Inbreeding;    Immunity;    Immunoglobulin;    Leukocyte;    Life history;    Pinniped;    Zalophus wollebaeki;    Galapagos;   

DOI  :  10.1186/s12862-015-0519-6

 received in 2015-03-09, accepted in 2015-10-23,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundA multitude of correlations between heterozygosity and fitness proxies associated with disease have been reported from wild populations, but the genetic basis of these associations is unresolved. We used a longitudinal dataset on wild Galapagos sea lions (Zalophus wollebaeki) to develop a relatively new perspective on this problem, by testing for associations between heterozygosity and immune variation across age classes and between ecological contexts.ResultsHomozygosity by locus was negatively correlated with serum immunoglobulin G production in pups (0–3 months of age), suggesting that reduced genetic diversity has a detrimental influence on the early development of immune defence in the Galapagos sea lion. In addition, homozygosity by locus was positively correlated with total circulating leukocyte concentration in juveniles (6–24 months of age), but only in a colony subject to the anthropogenic environmental impacts of development, pollution and introduced species, which suggests that reduced genetic diversity influences mature immune system activity in circumstances of high antigen exposure.ConclusionsThese findings demonstrate the environmental context-dependency of the phenotypic expression of immune variation, which is implicit in the theory of ecoimmunology, but which has been rarely demonstrated in the wild. They also indicate that heterozygosity may be linked to the maintenance of heterogeneity in mammalian immune system development and response to infection, adding to the body of evidence on the nature of the mechanistic link between heterozygosity and fitness.

【 授权许可】

CC BY   
© Brock et al. 2015