Selection on MHC class II supertypes in the New Zealand endemic Hochstetter’s frog

BMC Evolutionary Biology

Research Article

Jolene T Sutton¹  Phillip J Bishop²  Mette Lillie³  Katherine Belov³  Catherine E Grueber⁴  Robyn Howitt⁵  Dianne Gleeson⁶ 

[1] Department of Biology, University of Hawai’i at Mānoa, Honolulu, USA;Department of Biology, University of Otago, Dunedin, New Zealand;Faculty of Veterinary Science, University of Sydney, Sydney, Australia;Faculty of Veterinary Science, University of Sydney, Sydney, Australia;San Diego Zoo Global, San Diego, USA;Landcare Research, Auckland, New Zealand;Landcare Research, Auckland, New Zealand;Institute for Applied Ecology, University of Canberra, Bruce, Australia;

关键词: Conservation genetics;    Leiopelma hochstetteri;    Fragmentation;    Balancing selection;    Genetic drift;   

DOI  :  10.1186/s12862-015-0342-0

 received in 2014-12-11, accepted in 2015-03-27,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe New Zealand native frogs, family Leiopelmatidae, are among the most archaic in the world. Leiopelma hochstetteri (Hochstetter’s frog) is a small, semi-aquatic frog with numerous, fragmented populations scattered across New Zealand’s North Island. We characterized a major histocompatibility complex (MHC) class II B gene (DAB) in L. hochstetteri from a spleen transcriptome, and then compared its diversity to neutral microsatellite markers to assess the adaptive genetic diversity of five populations (“evolutionarily significant units”, ESUs).ResultsL. hochstetteri possessed very high MHC diversity, with 74 DAB alleles characterized. Extremely high differentiation was observed at the DAB locus, with only two alleles shared between populations, a pattern that was not reflected in the microsatellites. Clustering analysis on putative peptide binding residues of the DAB alleles indicated four functional supertypes, all of which were represented in 4 of 5 populations, albeit at different frequencies. Otawa was an exception to these observations, with only two DAB alleles present.ConclusionsThis study of MHC diversity highlights extreme population differentiation at this functional locus. Supertype differentiation was high among populations, suggesting spatial and/or temporal variation in selection pressures. Low DAB diversity in Otawa may limit this population’s adaptive potential to future pathogenic challenges.

【 授权许可】

Unknown   
© Lillie et al.; licensee BioMed Central . 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.