Expression patterns of genes associated with muscle growth and adipose deposition during growth and development of female Tibetan pigs

摘要

Changes in expression of 140 genes associated with growth and adipose deposition in the logissimus dorsi muscle were studied at various growth stages, in Tibetan, Taihu and Landrace pigs, using a pathway-focused oligo microarray. Analysis of variance (ANOVA) revealed statistically significant differences in the expression of 17 genes in Tibetan pigs at 4 stages (2,4,6 and 8 months of age). Significant differences were also identified in the expression of 28 genes, at 2 months of age, in all 3 pig breeds. Tibetan pigs had significantly lower body weights than Taihu and Landrace pigs, at two months, and a larger myofiber cross-sectional area (CSA). Cluster analysis revealed a significant (P<0.01) level of expression of 2 genes in Tibetan pigs, and strong down-regulation, or up-regulation of genes between 2-8 months. Quantitative, real time RT-PCR was used to verify the microarray data for five modulated genes, a good correlation between the two measures was observed for Tibetan pigs at different growth stages (R=0.856 ± 0.109). These results indicate that, in Tibetan pigs aged 2-8 months, growth intensity for muscle is higher than for intramuscular fat. The genes that exhibited down-regulation were mainly those controlling fatty acid biosynthesis. Genes that were up-regulated were concerned mainly with fatty acid b –oxidation and myofibre groth; more so than in Tibetan pigs than in the other breeds at 2 months of age. These results are consistent with the unique genetic characteristics of Tibetan pigs, which are adapted to unusual ecological conditions in the high plateau areas [ Acta Zoologica Sinica 54(3): 442– 452, 2008].