Relationship between the expression levels of myogenic regulatory factor genes and carcass characteristics in Kivircik and Hungarian Merino lambs

This study aimed to investigate the expression profiles of the myogenic regulatory genes <i>MYOD1, MYOG, MYF5, MYF6</i>, and <i>MSTN</i> in <i>longissimus dorsi muscle,</i> as well as the correlation of the expression levels of these genes with carcass characteristics and growth performance in the Kivircik and Hungarian Merino sheep breeds. The expression levels of the <i>MYF5, MYF6,</i> and <i>MYOG</i> genes were found to be significantly correlated with the rib proportion, the expression level of the <i>MYOG</i> gene was identified as being the main determinant of variations in the rib proportion in the Kivircik lambs. The regression analysis results revealed that the expression levels of the <i>MYF5</i> and <i>MSTN</i> genes played an essential role in determining the cold carcass dressing percentage in Hungarian Merino lambs. Further, as a result of the regression analysis, the model including the expression level of the <i>MYF6</i> gene demonstrated that this gene could be responsible for 36.4% of the differences observed in cold carcass weight. In conclusion, the findings of this study suggest that the expression levels of the <i>MYF5, MYF6,</i> and <i>MYOG</i> genes were associated with various carcass traits, particularly in the Kivircik breed, and these genes hold potential as markers for enhancing breed productivity.