Association between growth hormone gene polymorphisms and growth traits in Cyprinus carpio from the Caspian Sea

Abstract

Growth hormone (GH) is the most important hormone that controls somatic cell growth and the syntheses of protein, fat, and carbohydrates. This study was to identify gene polymorphism of GH-1 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 150 carp at 4 age classes of 4, 6, 12 and 24 months were randomly selected and DNA was extracted from caudal fin by modified salting out method. A fragment of 373 bp from exon 4, intron 4, and exon 5 of GH-1 gene was amplified using polymerase chain reaction (PCR). The genotyped samples by SSCP analysis yielded 8 different banding patterns as A, B, C, D, E, F, G and H with frequencies of 31.33, 10.67, 20.67, 22.67, 4.0, 2.0, 2.67 and 6.0 %, respectively. Analysis of marker-trait correlation by General Linear Model (GLM) showed significant associations between carp's GH-1 banding patterns and body weight, but the gene was not significantly associated with TL and CF parameters. The body weights of with a banding pattern of D were significantly (P<0.05) heavier than the other genotypes. Considering the economic importance of common carp and positive association between body weight and the banding pattern found in this study, the marker site in GH-1 gene could be used in marker-assisted selection (MAS) in this species. To achieve a reliable conclusion, further experiments should employ an appropriate sample size.