Exome sequencing identifies variants associated with semen quality in Holstein Friesian and Hallikar bulls

Abstract

Effective fertility of bulls is dependent on semen quality, often determined based on standard semen evaluation tests. Here we report Whole Exome Sequencing (WES) of 12 bulls from two breeds Holstien Friesian and Hallikar selected based on Ejaculate Rejection Rate (ERR). We explored the possibility of identifying genetic variants from the conserved protein coding regions of genome. A total of 10,510 SNPs and 10.236 INDELs were identified post alignment against reference genome (ARS-UCD 1.2) and were annotated using SnpEff. The number of variants with high and modifier functional impact detected were 145 and 19,122, respectively. Genetic variants common to both high and low ERR group bulls among Holstein Friesian were 08 and in Hallikar the common variants were 51. Prominent genesviz. UCP2, PANK2, GPD2, PTPRG, LARP7, EZH1, DENND1B and TDRD9 with a role in determining the semen quality were observed to be carriers of the genetic variant.