Association between growth hormone gene polymorphisms and growth traits in wild common carp, Cyprinus carpio from the Caspian Sea

Growth hormone (GH) is the most important hormone that controls somatic cell growth and syntheses of protein, fat, and carbohydrates. This study was conducted to identify gene polymorphism of GH-۱ using PCR -single strand conformation polymorphism (SSCP) technique and its association with growth traits including condition factor (CF), body weight (BW) and total length (TL) in common carp (Cyprinus carpio). A total of ۱۵۰ carps in ۴ age classes of ۴, ۶, ۱۲ and ۲۴ months were randomly selected and DNA was extracted from the caudal fin by modified salting out method. A fragment of ۳۷۳ bp from exon ۴, intron ۴, and exon ۵ of GH-۱ gene was amplified using polymerase chain reaction ( PCR ). Genotyping of samples by SSCP analysis yielded ۸ different banding patterns as A, B, C, D, E, F, G and H with frequencies of ۳۱.۳۳, ۱۰.۶۷, ۲۰.۶۷, ۲۲.۶۷, ۴.۰, ۲.۰, ۲.۶۷ and ۶.۰ %, respectively. Analysis of marker-trait correlation by General Linear Model (GLM) showed significant associations between carp GH-۱ banding patterns and body weight, but the gene was not significantly associated with TL and CF parameters. The body weights of fish with a banding pattern of D were significantly (p<۰.۰۵) higher than the other genotypes. Considering the economic importance of common carp and the positive association between body weight and the banding pattern found in this study, the marker site in GH-۱ gene could be used in marker-assisted selection ( MAS ) in this species. To achieve a reliable conclusion, further experiments employing an appropriate sample size are required.  

Keywords:

Cyprinus carpio , Growth hormone gene , PCR-SSCP.