A Deletion Downstream of theCHCHD7Gene Is Associated with Growth Traits in Sheep

Simple Summary The genesCHCHD7andPLAG1are located on the same growth-related major quantitative trait locus of sheep.PLAG1affects sheep growth, but no corresponding studies have been conducted onCHCHD7. However, polymorphisms in theCHCHD7gene are associated with carcass weight and muscle formation in cattle, body height in cattle and humans, and weaning weight in Duroc pigs. In this study, the mathematical expectation method was used to analyze an 8-bp deletion mutation located downstream of theCHCHD7gene in 2350 individuals from seven sheep breeds. The associations between wild-type and deletion genotypes and growth traits in Tan sheep were also analyzed. The 8-bp deletion locus was significantly associated with body length (p= 0.032), chest depth (p= 0.015), and chest width (p= 0.047) of Tan sheep. Additionally, wild-type genotype carriers were more numerous than those heterozygous for the deletion genotype. Thus, the genotyped 8-bp deletion downstream of theCHCHD7gene may be associated with growth and development 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.PLAG1affects sheep growth, but the effects ofCHCHD7have not been determined. In this study, an 8-bp deletion downstream ofCHCHD7was 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 theCHCHD7gene might be associated with growth and development traits of sheep.