Single nucleotide polymorphisms in the CDH18 gene affect growth traits in Hu sheep

Growth traits are critical economic traits in sheep. Genetic polymorphism has a great influence on the improvement of sheep traits. The aim of this study was to analyze the effect of cadherin 18 (CDH18) gene polymorphisms on growth traits in Hu sheep. The single nucleotide polymorphisms (SNPs) of the CDH18 gene in Hu sheep were identified by Illumina Ovine SNP 50K BeadChip. Five SNPs were screened out within the CDH18 gene, where SNP1 (rs423955510) was located in exon and SNP2 (rs412944692), SNP3 (rs416959317), SNP4 (rs398980439) and SNP5 (rs428685044) were located in intron. The expression of the CDH18 gene in Hu sheep tissue was analyzed using quantitative real‐time polymerase chain reaction, and the structure and phylogeny of the gene were analyzed using bioinformatics techniques. The results showed that SNP1, SNP2, SNP4, and SNP5 were significantly associated with body weight and body size (p < 0.05). Meanwhile, there were strong linkage disequilibrium relationships between SNP1 and SNP2 (r2 > 0.33). The CDH18 gene was expressed in the muscle tissues of Hu sheep at different months. The relative expression levels at weaning and 4‐month muscle tissue were higher. Bioinformatic analysis revealed that SNP1 existed in the 5′ untranslated regions, which might affect the efficiency of translation. The above findings suggested that these SNP loci might affect growth traits and could be regarded as potential molecular markers for improving the growth performance of Hu sheep, which lay a molecular foundation for the breeding of sheep and accelerate the pace of sheep breeding.