Copy number variation of CADM2 gene revealed its association with growth traits across Chinese Capra hircus (goat) populations.

Copy number variations (CNVs) are the wide structural variations ranging from 50 bp to several Mb at genome which can affect gene expression and further impacting growth and development traits of livestock. Comparing with single nucleotide polymorphisms (SNPs), CNVs can better explain the genetic and phenotypic diversity, are increasingly important in biological research. As a member of immunoglobulin super-family, cell adhesion molecule 2 (CADM2) plays a vital role in cancer development and metabolic regulation. Here, we tested the CNV of CADM2 gene in 443 goats across five breeds (Guizhou white goat, GZW; Guizhou black goat, GZB; Africa Nubian goat, AN; Boer goat × Huai goat, BH; Boer goat, BG) and detected its association with phenotypic traits. Subsequently, we analyzed the CADM2 gene expression level in different tissues of NB goats (n = 3, Nubian × Black) and the transcriptional expression in lung is much higher than others. The results showed that the CNV of CADM2 has a significant association with withers height and body length in GZB goat (P < 0.01), in which individuals with type of deletion were superior to those with duplication or normal type in term of body hight and body length (P < 0.01). In summary, this study confirmed the association between CNV of CADM2 gene and growth traits, and our research data indicated the CADM2-CNV may considered as a prospective candidate for the molecular marker-assisted selection breeding of goat growth traits, which conducived to accelerating the genetic amelioration in Chinese goats.