Single nucleotide polymorphisms of Δ6-desaturase and Elovl5 segments and their associations with common carp (Cyprinus carpio) growth traits.

Highly unsaturated fatty acids (HUFAs) are crucial for the nutritional health, physiology, and reproduction of vertebrates. The Δ6-desaturase and Elovl5 elongase genes produce essential enzymes in the biosynthetic pathway of HUFAs. Single nucleotide polymorphism (SNP) analysis of genes functionally related to the growth traits of the common carp (Cyprinus carpio var. Jian) can provide useful information for common carp molecular breeding. In this study, we isolated two Δ6 Fad genes and two Elovl5 genes from the common carp. Polymerase chain reaction-restriction fragment length polymorphism was performed, and the genotypes of three SNPs (Δ6Fad-a intron 10_C73T, Δ6Fad-b intron 10_A56G, and Elovl5-a intron 5_C64A) in 712 individuals (383 females and 329 males) were detected. Correlation analysis between the genotypes and weight gain revealed that intron 10_C73T of Δ6Fad-a, intron 10_A56G of Δ6Fad-b, and intron 5_ C64A of Elovl5-a were significantly associated with common carp weight gain. Weight gain increased with the enrichment of molecular SNP markers, consistent with the characteristics of quantitative traits. Our results indicate that Δ6Fad and Elovl5 elongase genes could be candidate genes for the molecular breeding of the common carp. This study provides useful information for the improvement of this species.