Growth hormone-releasing hormone (GHRH) polymorphisms associated with carcass traits of meat in Korean cattle

Abstract

Background: Cold carcass weight (CW) and longissimus muscle area (EMA) are the major quantitative traits in beef cattle. In this study, we found several polymorphisms of growth hormone-releasing hormone (GHRH) gene and examined the association of polymorphisms with carcass traits (CW and EMA) in Korean native cattle (Hanwoo).

Results: By direct DNA sequencing in 24 unrelated Korean cattle, we identified 12 single nucleotide polymorphisms within the 9 kb full gene region, including the 1.5 kb promoter region. Among them, six polymorphic sites were selected for genotyping in our beef cattle (n = 428) and five marker haplotypes (frequency > 0.1) were identified. Statistical analysis revealed that -4241A>T showed significant associations with CW and EMA.

Conclusion: Our findings suggest that polymorphisms in GHRH might be one of the important genetic factors that influence carcass yield in beef cattle. Sequence variation/haplotype information identified in this study would provide valuable information for the production of a commercial line of beef cattle.

Figure 1

Map of SNPs in GHRH on chromosome 13. The exons are marked by black block, and 5' and 3' UTRs indicated by open blocks. First base of translational site is denoted as nucleotide +1. Asterisks (*) indicate polymorphisms genotyped in a larger Korean cattle (n = 428). ^†The minor allele frequency based on 24 sequencing samples only, which is different with minor allele frequency of absolutely linked SNP genotyped in larger population.