Polymorphisms and their association with growth traits in the growth hormone gene of yellow catfish, Pelteobagrus fulvidraco

Abstract

The growth hormone (GH) gene affects animal growth and is a potential target for genetic studies on variation related to growth traits. In this study, the GH gene of Pelteobagrus fulvidraco (yellow catfish) was cloned and characterized. The 3117bp genomic sequence of GH consisted of a 5′-untranslated region (UTR), five exons and four introns, and a 3′UTR. The full-length cDNA (603bp) of the gene had an open reading frame that encoded a polypeptide of 200 amino acids. GH was specifically expressed in the pituitary. Polymorphisms of the GH gene were evaluated for associations with growth traits in 180 yellow catfish individuals. Using direct sequencing, five single-nucleotide polymorphisms (SNPs) and four microsatellites (SSRs) were identified in the GH gene, with four SNPs in intron 4 (1674G>A, 2100A>G, 2154T>G, 2285T>C), one mutation in the 3′UTR (2822A>G), one SSR in intron 1 (GH-AC) and intron 3 (GH-AT), and two SSRs in the 3′UTR (GH-GA, GH-TCTT). Notably, three SNPs (2100A>G, 2285T>C, 2822A>G) and three SSRs (GH-AC, GH-GA, GH-TCTT) were significantly associated with growth traits in yellow catfish. In conclusion, these SNPs and SSRs in the GH gene could be used for marker-assisted selection (MAS) in yellow catfish breeding. Statement of relevanceApplying genomic methods to the selection of the superior parents had the potential to improve the productivity and commercial value of yellow catfish. The cultivation of new varieties of Pelteobagrus fulvidraco which fast growth, high physical, rich nutrition and health for the aquaculture industry has great influence. SummaryThis study cloned GH gene DNA sequence 3117bp of yellow fish for the first time, this GH have high expression in pituitary tissue, only a few or no expression in other tissues; Five SNPs have been detected, which sites 1674G>A and 2154T>G have unrelated with growth traits; The site 2100A>G have highly significant correlation with body thickness, the site 2285T>C have significant correlation with caudal peduncle length, the site 2822A>G have correlation with total length and caudal peduncle, and have highly significant correlation with body length and caudal peduncle length. Four SSRs have been detected, site of AT has been unrelated with growth traits; site of GA has correlation with weight, body length, body height, body thickness, and have highly significant correlation with full length, caudal peduncle length; site of TCTT has correlation with head length, caudal peduncle height, and site of AC have correlation with body thickness, head length.