Association study between single nucleotide polymorphisms in leptin and growth traits in Cyprinus carpio var. Jian.

Leptin is a hormone that affects the regulation of body weight, energy expenditure, fat metabolism, food intake, and appetite. In this study, we cloned the jlLEP-A1 and jlLEP-A2 genes in Jian carp (Cyprinus carpio var. Jian) and performed an association analysis between identified polymorphisms and growth traits. Three polymorphisms in exons of jlLEP-A1 (A1-T113C) and jlLEP-A2 (A2-G415A and A2-G427A) were identified, and genotyped by the polymerase chain reaction - restriction fragment length polymorphism method in 263 female and 294 male Jian carp. All three SNPs were missense mutations. Association analysis revealed that the three SNPs were significantly associated with growth traits in male Jian carp. Only SNP A1-T113C was significantly associated with growth traits in female Jian carp. Analysis of diplotypes derived from jlLEP-A2 SNPs revealed an association with growth traits in male but not female Jian carp. These results demonstrate that polymorphisms in the leptin gene are associated with growth traits and may be used for marker-assisted selection programs in Jian carp breeding and production.