Characterization of genetic variation and basis of inflammatory bowel disease in the Toll-like receptor 5 gene of the red wolf and the maned wolf

Abstract

Characterizing Toll-like receptors across taxa can lead to an increasingly accurate documentation of the evolutionary processes acting within this receptor class, as well as a greater understanding of the diseases associated with these receptors. This study examines 2 sequenced portions of the Toll-like receptor 5 (TLRS5) protein coding gene in 2 imperiled canid species: the Near Threatened maned wolf Chrysocyon brachyurus and the Critically Endangered red wolf Canis rufus, to characterize genetic variation and investigate the presence of single nucleotide polymorphisms (SNPs) previously associated with canine inflammatory bowel disease (IBD). Both maned and red wolves suffer from inflammatory bowel disease, threatening the sustainability of their crucial ex situ populations. Here we report novel polymorphic positions found in maned and red wolf TLR5, differences in variation with regard to nucleotide polymorphisms and resulting amino acid variation among maned wolves, red wolves, gray wolves and domestic dogs. Domestic dog SNPs associated with IBD were not found to be polymorphic in maned wolves and red wolves. Samples of both focal species and gray wolves lack the protective alleles present in many dog breeds, suggesting a potential genetic predisposition for IBD in these 2 wild canid species and a possible development of these protective alleles post domestication. This potential predisposition informs ex situ management practices and treatment for IBD.