A Deletion Downstream of the CHCHD7 Gene Is Associated with Growth Traits in Sheep

In sheep, the coiled-coil-helix-coiled-coil-helix domain containing 7 (CHCHD7) gene and the pleiomorphic adenoma gene 1 (PLAG1) are on the same growth-related major quantitative trait locus, positioned head-to-head approximately 420 bp apart on chromosome 9. PLAG1 affects sheep growth, but the effects of CHCHD7 have not been determined. In this study, an 8-bp deletion downstream of CHCHD7 was analyzed in 2350 sheep from seven breeds. The associations between the deletion and growth traits of Tan sheep were also determined. Both genotypes (homozygous wild-type and heterozygous) for the 8-bp deletion were found in Tan (TS), Luxi Blackhead (LXBH), Small-Tail Han (STHS), and Lanzhou Fat-Tail (LFTS) sheep. However, there were no polymorphic sites for the mutation in Hu (HS), Sartuul (SS), and Australian White (AUW) sheep. In TS, LXBH, STHS, and LFTS sheep, the deletion genotype was less frequent than the wild-type genotype, and the allele frequencies of the deletion variant were 0.007 (TS), 0.011 (LBXH), 0.008 (STHS), and 0.010 (LFTS). The 8-bp deletion was significantly associated with body length (p = 0.032), chest depth (p = 0.015), and chest width (p = 0.047) in Tan sheep. Thus, the 8-bp deletion downstream of the CHCHD7 gene might be associated with growth and development traits of sheep.