Expression profiles and associations of FGF1 and FGF10 with intramuscular fat in Tibetan chicken.

1. FGF1 and FGF10, two paracrine members of the fibroblast growth factor (FGF) gene family, play critical roles in the development, structural and metabolic remodelling of adipose tissue. 2. The objective of this study was to investigate the expression profiles of FGF1 and FGF10 genes in breast muscle and thigh muscle in 5 developmental stages (1, 81, 119, 154 and 210 d old) in Tibetan chickens. The possible relationships between expression of these genes and intramuscular fat (IMF) content were analysed in Tibetan chickens. 3. Expression profiles showed that FGF1 and FGF10 mRNA were ubiquitously expressed in various tissues of 154-d-old Tibetan chickens. Lung tissue contained the highest amount of FGF1 and FGF10 mRNA while breast muscle and thigh muscle exhibited lower levels of FGF1 and FGF10 mRNA in both males and females compared with other tissues (P < 0.05). Temporal expression of FGF1 and FGF10 in breast and thigh muscle showed similar tendencies in males and females, respectively, with peaks in thigh muscle at 119-d-old and breast muscle in 1-d-old males and females, respectively. 4. Correlation analysis suggested that gender had an influence on the relationships of FGF1 and FGF10 expression with IMF content in thigh muscle. The RNA levels of FGF1 and FGF10 genes in male thigh muscle were positively related to IMF content of Tibetan chickens (P < 0.01), while the correlations were shown to be negative in female thigh muscle (P > 0.05). 5. These results provide a basis for functional elucidation of FGF1 and FGF10 genes on adipocyte development and intramuscular fat deposition, as well as selective breeding and resource exploration of local poultry breeds.

Differences in mitochondrial gene expression profiles, enzyme activities and myosin heavy chain types in yak versus bovine skeletal muscles.

Hypoxia can affect energy metabolism. We examined gene expression and enzyme activity related to mitochondrial energy metabolism, as well as myosin heavy chain (MyHC) types in yaks (Bos grunniens) living at high altitudes. Real-time quantitative PCR assays indicated that the yak has significantly lower levels of carnitine palmitoyltransferase (CPT) mRNA in the biceps femoris and lower levels of uncoupling protein 3 (UCP3) mRNA in both biceps femoris and longissimus dorsi than in Yellow cattle. No significant differences between yak and Yellow cattle were observed in the activities of mitochondrial ß-hydroxyacyl-CoA dehydrogenase, isocitrate dehydrogenase and cytochrome oxidase in the same muscles. Semi-quantitative RT-PCR analysis showed that the MyHC 1 mRNA levels in yak biceps femoris was lower than in Yellow cattle. We conclude that the yak has significantly lower mRNA levels of CPT, UCP3, and MyHC 1 in biceps femoris than in Yellow cattle, suggesting that the yak biceps femoris has lower fatty acid oxidation capacity and greater glycolytic metabolic potential.