Enzyme Activities and Gene Expression of Yak Skeletal Muscles

The purpose of the present study was to characterize the metabolic enzyme activities and gene expression levels in yak skeletal muscles. Yak longissimus dorsi had higher lactate dehydrogenase (LDH) activity, lower activities of malate dehydrogenase (MDH), β-hydroxyacyl-CoA dehydrogenase (HOAD) and cytocrome c oxidase (COX) compared with biceps femoris. Meanwhile, native PAGE of muscle extracts revealed that longissimus dorsi had higher proportion of LDH5 compared with biceps femoris. These data indicate the less oxidative metabolic orientation of yak longissimus dorsi. Semi-quantitative RT-PCR analysis revealed no significant difference in the expression of four genes including adipocyte fatty acid-binding protein (A-FABP), peroxisome proliferator-activated receptor gamma 2 (PPARγ2), myosin heavy chain 1 (MyHC1) and peroxisome proliferator-activated receptor coactivator 1α (PGC-1α) between yak longissimus dorsi and biceps femoris.