The CNV map construction and ROH analysis of Pinan cattle.

Pinan cattle, as the progeny of crossbreeding improvement between Nanyang cattle and Piedmontese, have attracted attention for their excellent growth performance. In this study, we constructed a copy number variation map by whole genome resequencing of 132 Pinan cattle. In the genome of Pinan cattle, deletion-type copy number variants occupied a higher proportion and only 3.31% of CNVRs overlapped with exonic regions. It showed that Pinan cattle was clearly distinguishable from other breeds and Pinan cattle was closer to Nanyang cattle by population genetic structure analysis based on CNVRs. The degree of inbreeding in the Pinan cattle population was explored by ROH analysis, which showed that the degree of inbreeding in Pinan cattle was lower than that in European beef cattle, suggesting that the risk of inbreeding was low. Candidate genes related to muscle development (CADM3, CNTFR, DOCK3), reproductive traits (SCAPER), embryonic development (RERE) and immune traits (CD84) were identified by V selection analysis, ROH islands and iHS selection analysis, which provided a new scientific basis for the genetic basis of the excellent traits in Pinan cattle.