Sequence variability and protein domain architectures for bovine Toll-like receptors 1, 5, and 10

Abstract

The mammalian Toll-like receptors (TLRs) play an important role in the recognition of invading pathogens and the modulation of innate immune responses. The primary objective of this study was to characterize single nucleotide polymorphisms (SNPs) and insertion–deletion polymorphisms (indels) within bovine TLRs 1, 5, and 10, thereby facilitating future TLR signaling and association studies relevant to bovine innate immunity. Comparative sequence analysis for 10 bovine breeds derived from Bos taurus and Bos indicus revealed 98 polymorphisms (92 SNPs and 6 indels), with at least 14 nonsynonymous SNPs located within predicted TLR domains considered to be of functional significance. Of the 98 polymorphisms detected, 94 are reported here for the first time. Notably, 2 nonsynonymous SNPs were determined to modulate the prediction of a novel leucine-rich repeat (LRR) domain within B. indicus TLR5. Prediction and comparison of TLR protein domain architectures for multiple species revealed seven conserved regions of LRR patterning associated with the three genes investigated.