A promoter polymorphism of MSTN g.-371T>A and its associations with carcass traits in Korean cattle.

A promoter polymorphism of bovine Myostatin (MSTN) gene g.-371T>A was screened in Holstein and two Korean indigenous cattle breeds, Hanwoo and Jeju Black cattle (JBC). The MSTN g.-371T>A polymorphism was found in all three cattle breeds tested. An allele MSTN g.-371A was the most frequent in the JBC breed among breeds tested. The association of MSTN genotypes for carcass traits was also tested in the Hanwoo population. Significant differences were found between the genotypes and level of meat quality grade index which converted the marbling score levels (P < 0.05), reflecting the metabolic role of MSTN for inhibition of preadipocyte differentiation in intramuscular fat deposition. In addition, significant differences were found for fat color index of backfat according to MSTN genotypes (P < 0.05), suggesting that MSTN may play a role in deposition of white-yellow adipocytes in backfat. However, there was no detection of significant association of genotypes with the live weight, carcass weight, backfat thickness, eye muscle area, marbling score, or meat color index (P > 0.05). Despite the lack of statistical association, wild type g.-371T/-showed association patterns similar to those of A/A homozygotes, such as heavier weights, thinner backfat, larger eye muscle area, and lower marbling score. The results of the present study suggest that MSTN promoter polymorphism g.-371T>A may affect carcass traits, which could be a useful molecular marker for planning improvements in the economic traits of Korean cattle breeds.