Characteristics of genetic basis copy number variation in production and adaptation traits of Chinese indigenous sheep.

Copy number variations(CNVs)range in size from 50 base pairs(bp)to several megabases(Mb)and encompass various types of structural variations,such as insertions,deletions,duplications,and complex multiallelic events(MacDonald et al.,2014).These genomic alterations modulate phenotype by altering gene dosage and transcriptional regulation,and are key drivers of biological evolu-tion and determinants of genetic diversity and phenotypic variation.