Whole-genome sequencing reveals selection signatures associated with important traits in six goat breeds

Comparative population genomics analysis is an effective approach to identify selection signatures in farm animals. In this study, we systematically investigated the selection signatures in six phenotypically diverse goat breeds using SNPs obtained from pooled whole-genome resequencing data. More than 95.5% of 446-642 million clean reads were mapped to the latest reference goat genome, which generated a sequencing depth ranging from 22.30 to 31.75-fold for each breed. A total of 5,802,307, 6,794,020, 7,562,312, 5,325,119, 8,764,136, and 9,488,057 putative SNPs were detected in Boer, Meigu, Jintang Black, Nanjiang Yellow, Tibetan, and Tibetan cashmere goats, respectively. Based on the genome-wide F_ST and expected heterozygosity scores along 100-kb sliding windows, 68, 89, 44, 44, 19, and 35 outlier windows were deemed as the selection signatures in the six goat breeds. After genome annotation, several genes within the selection signals were found to be possibly associated with important traits in goats, such as coat color (IRF4, EXOC2, RALY, EIF2S2, and KITLG), high-altitude adaptation (EPAS1), growth (LDB2), and reproduction traits (KHDRBS2). In summary, we provide an improved understanding of the genetic diversity and the genomic footprints under positive selection or the adaptations to the local environments in the domestic goat genome.