Genome-wide SNP analysis reveals the selection signatures of two indigenous buffalo breeds in Sichuan

Sichuan Province spawned abundant of indigenous buffalo varieties, which probably harbor valuable gene resources beneficial to the genetic improvement of buffalo. However, limited genetic information was publicly available. To better understand their selection signatures between different populations, we performed a restriction site-associated DNA sequencing (RADseq) to explore genome-wide SNPs among two indigenous breeds of Sichuan buffaloes. As a result, a total of 2,110,077 high-quality SNPs were finally obtained. Population genetic analysis indicated a obviously genetic differentiation between two breeds. The detection of selective genes showed that 995 and 910 protein-coding genes underwent positive selection in Yibin buffalo (GYBS) and Dechang buffalo (XCS). Further functional analysis revealed distinctly discrepant selection in two breeds. Candidate genes that positively selected from Yibin buffaloes have mainly occurred in functions closely related to meat quality, complex living environment adaption capability, and disease resistance. While they were significantly enriched in cell proliferation and cell components in Dechang buffalo, indicating the selection pressure primarily derived from the requirement of organism growth and development speed during breed formation. Our dataset constitutes a promising reservoir of genome-wide SNP markers of Sichuan buffaloes and provides potentially traits selected in different local populations. Such comprehensive genetic resources offer an unprecedented opportunity for genetic association analysis of economically important traits and precision breeding programs in buffaloes.