Analyzing the exome heterogeneity of cattle immunity genes with the method of flow-cell sequencing

Abstract

Toll-like receptors belong to the pattern-recognition receptors (PRRs), which have evolved to recognize conserved features of bacterial and viral molecules. We used the approach developed earlier to screen for the polymorphism in TLR genes in a representative set of historical and modern cattle breeds from Russia. The method pipeline included the steps of obtaining the overlapping amplification products from the coding regions of all ten bovine TLR genes, their subsequent purification and normalization. While the anti-bacterial group included TLR1, -2, -4, -5 and -6, the anti-viral group compressed TLR3, -7, -8, -9 and -10 (in spite of its unclear specificity). Animals from the about seven breeds, both bulls and cows, was used for analysis. The samples from the pooled genomic DNA were sequenced on the PacBio platform. After identification of variations, Bayesian analysis was carried out, followed by filtration on quality of sequencing. The 5-36 structural variants of TLRs were annotated according to their biological significance. Both new and already identified sites of variability, already annotated and documented in dbSNP, have been found. The data are needed for further breeding of local breeds in Russia with respect to their natural resistance to various diseases.