Single-step genome-wide association studies and post-GWAS analyses for the number of oocytes and embryos in Gir cattle

Abstract

Genome-Wide Association Studies (GWAS) are used for identi cation of quantitate trait loci (QTL) and genes associated with several traits. We aimed to identify QTLs, genes, and biological processes associated with number of total and viable oocytes, and number of embryos in Gir dairy cattle. A dataset with 17,526 follicular aspirations, including the following traits: number of viable oocytes (VO), number of total oocytes (TO) and number of embryos (EMBR) from 1,641 Gir donors was provided by ve different stock farms. A genotype le with 2,093 animals and 395,524 SNP markers was used to perform a singlestep GWAS analysis for each trait. The top 10 windows with the highest percentage of additive genetic variance explained by 100 adjacent SNPs were selected. QTLs were identi ed on chromosomes 1, 2, 5, 6,