THREE SNPS POLYMORPHISM OF GROWTH HORMONE-RELEASING HORMONE GENE (GHRH) AND ASSOCIATION ANALYSIS WITH GROWTH TRAITS IN CHANNEL CATFISH

This study assessed the effects of growth hormone-releasing hormone (GHRH) gene on channel catfish (Ictalurus punctatus) growth traits by identifying SNPs of GHRH gene by The Pooled DNA sequencing using 176 individuals from core breeding population of channel catfish by multiplex SNaPshot genotyping method and analyzing the associations between growth traits with genotypes and diplotypes of GHRH SNPs. Four SNPs (g.4333 AG, g.4616 AC, g.4632AT and g.6301 GA) were identified in intron, and three of them were genotyped successfully, and there were no strong LD between the SNPs. Six haplotypes and six diplotypes were found in these 176 channel catfish. Association analysis between these SNPs and growth traits showed that the individual with genotype AA of the mutation g.6301 GA had significantly higher body mass and body length than those with genotype GG and AG (P0.05); H1/H4 and H1/H5 of six diplotypes had the highest body mass and body length, which were significantly (P0.01) higher than those of the other diplotypes. This study provide basic knowledge for marker-assisted breeding and QTL of growth traits of channel catfish.