title: Variation at innate immunity Toll-like receptor genes in a bottlenecked population of a New Zealand robin.
abstract: 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.
authors.affiliation: Department of Zoology, University of Otago, Dunedin, New Zealand. catherine.grueber@otago.ac.nz
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Grueber
authors.forename: Graham P
authors.initials: GP
authors.lastname: Wallis
authors.forename: Tania M
authors.initials: TM
authors.lastname: King
authors.forename: Ian G
authors.initials: IG
authors.lastname: Jamieson
mesh_terms: D000818:Animals; D056727:Endangered Species; D005091:Exons; D020440:Gene Duplication; D005838:Genotype; D007113:Immunity, Innate / Q000235:genetics*; D018895:Microsatellite Repeats; D009520:New Zealand; D020641:Polymorphism, Single Nucleotide; D012641:Selection, Genetic; D020308:Songbirds / Q000235:genetics* / Q000276:immunology*; D051199:Toll-Like Receptor 7 / Q000235:genetics; D051193:Toll-Like Receptors / Q000235:genetics* / Q000276:immunology*
chemical_list: D051199:Toll-Like Receptor 7; D051193:Toll-Like Receptors