Open AccessVariation at Innate Immunity Toll-Like Receptor Genes in a Bottlenecked Population of a New Zealand Robin
Author(s) -
Catherine E. Grueber,
Graham P. Wallis,
Tania M. King,
Ian G. Jamieson
Publication year - 2012
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0045011
Subject(s) - biology , genetics , population , locus (genetics) , balancing selection , genetic variation , major histocompatibility complex , genotyping , gene , human evolutionary genetics , evolutionary biology , innate immune system , genome , genotype , immune system , demography , sociology
Toll-like receptors (TLRs) are an ancient family of genes encoding transmembrane proteins that bind pathogen-specific molecules and initiate both innate and adaptive aspects of the immune response. Our goal was to determine whether these genes show sufficient genetic diversity in a bottlenecked population to be a useful addition or alternative to the more commonly employed major histocompatibility complex (MHC) genotyping in a conservation genetics context. We amplified all known avian TLR genes in a severely bottlenecked population of New Zealand's Stewart Island robin ( Petroica australis rakiura ), for which reduced microsatellite diversity was previously observed. We genotyped 17–24 birds from a reintroduced island population (including the 12 founders) for nine genes, seven of which were polymorphic. We observed a total of 24 single-nucleotide polymorphisms overall, 15 of which were non-synonymous, representing up to five amino-acid variants at a locus. One locus ( TLR1LB ) showed evidence of past directional selection. Results also confirmed a passerine duplication of TLR7 . The levels of TLR diversity that we observe are sufficient to justify their further use in addressing conservation genetic questions, even in bottlenecked populations.