ABSTRACT. Malate dehydrogenases 1 and 2 (MDH1 and MDH2), and malic enzyme 1 (ME1) play important roles in the Krebs cycle for energy metabolism. The mRNA abundance changes of MDH1, MDH2 and ME1 genes were measured across six different adipose tissues from the leaner Landrace and fatty Rongchang pig breeds using quantitative real-time PCR. The mRNA of MDH1, MDH2 and ME1 was more abundant in fatty Rongchang pigs than in leaner Landrace pigs. In both breeds, females exhibited higher adipocyte volume and mRNA abundance of MDH1, MDH2 and ME1 compared with males. These values were higher in the subcutaneous adipose tissue compared with visceral adipose tissue. Furthermore, mRNA abundance changes of MDH1, MDH2 and ME1 have the remarked significant positive correlation with adipocyte volume across the six adipose tissue types. We conclude that there are breed-, gender-and tissue-specific expression patterns of ME1, MDH1 and MDH2, which highlight their potential as candidate genes for selecting for fat volume in pigs.

Myostatin (MSTN) is expressed in the myotome and developing skeletal muscles, and acts to regulate the number of muscle fibers. Wuding chicken large body, developed muscle, high disease resistance, and tender, delicious meat, and are not selected for fast growth. Broiler chickens (Avian broiler) are selected for fast growth and have a large body size and high muscle mass. Here, 240 one-day-old chickens (120 Wuding chickens and 120 broilers) were examined. Twenty chickens from each breed were sacrificed at days 1, 30, 60, 90, 120, and 150. Breast and leg muscle samples were collected within 20 min of sacrifice to investigate the effects of MSTN gene expression on growth performance and carcass traits. Body weight, carcass traits, and skeletal muscle mass in Wuding chickens were significantly (P < 0.05) lower than those in broiler chickens at all time points. Breast muscle MSTN mRNA was lower in Wuding chickens than in broilers before day 30 (P < 0.05). After day 30, breast muscle MSTN expression was higher in Wuding chicken than in broilers (P < 0.05). Leg muscle MSTN mRNA expression was higher in Wuding chicken than in broilers at all ages except for day 60 (P < 0.05). Correlation analysis revealed that breast muscle MSTN expression has a greater effect in slow growing Wuding chickens than in the fast growing broilers. In contract, leg muscle MSTN mRNA level has a greater effect in broilers than in Wuding chickens. MSTN regulates growth performance and carcass traits in chickens.