Examination of polymorphisms in the sequence encoding the extracellular domain of Suffolk and Kazak sheep’s Toll-like receptor 7

Innate immune recognition of single-stranded RNA via Toll-like receptor 7 (TLR7) plays an important regulatory role in the development of the immune response. In the study, we used PCR-single-strand conformational polymorphism (PCR-SSCP) analysis to investigate genetic variations in the sequence encoding the ectodomain (ECD) of ovine TLR7. PCR was carried out using 12 different primer pairs (ECD-1– ECD-12), and polymorphisms were detected in the products for 4/12 pairs (ECD-2, -5, -6, and -7). ECD-2 and ECD -5 amplified products with mutations in Suffolk and Kazakstan sheep, while ECD-6 and ECD-7 amplified products with mutations only exist in Suffolk. The second pair of primers mutation in Suffolk does not conform to Hardy Weinberg equilibrium. As the mutations identified in this study may influence the structure and function of TLR7 and may thus affect the immune response to pathogens. The data indicate to undertake further disease associations studies to examine the usefulness of these findings in livestock breeding.