Genome-wide scan for selection signatures based on whole-genome re-sequencing in Landrace and Yorkshire pigs

We performed a genome-wide scan to detect selection signatures that showed evidence of positive selection in the domestication process by re-sequencing the whole genomes of Landrace and Yorkshire pigs. Fifteen annotated elements with 13 associated genes were identified using the Z-transformed FST (Z(FST)) method, and 208 annotated elements with 140 associated genes were identified using the Z-transformed heterozygosity (ZHp) method. The functional analysis and the results of previous studies showed that most of the candidate genes were associated with basic metabolism, disease resistance, cellular processes, and biochemical signals, and several were related to body morphology and organs. They included PPP3CA, which plays an essential role in the transduction of intracellular Ca2+-mediated signals, and WWTR1, which plays a pivotal role in organ size control and tumor suppression. These results suggest that genes associated with body morphology were subject to selection pressure during domestication, whereas genes involved in basic metabolism and disease resistance were subject to selection during artificial breeding. Our findings provide new insights into the potential genetic variation of phenotypic diversity in different pig breeds and will help to better understand the selection effects of modern breeding in Landrace and Yorkshire pigs.