Oxidative and glycolytic skeletal muscles show marked differences in gene expression profile in Chinese Qingyuan partridge chickens

<div><p>Oxidative and glycolytic myofibers have different structures and metabolic characteristics and their ratios are important in determining poultry meat quality. However, the molecular mechanisms underlying their differences are unclear. In this study, global gene expression profiling was conducted in oxidative skeletal muscle (obtained from the <i>soleus</i>, or SOL) and glycolytic skeletal muscle (obtained from the <i>extensor digitorum longus</i>, or EDL) of Chinese Qingyuan partridge chickens, using the Agilent Chicken Gene Expression Chip. A total of 1224 genes with at least 2-fold differences were identified (<i>P</i> < 0.05), of which 654 were upregulated and 570 were downregulated in SOL. GO, KEGG pathway, and co-expressed gene network analyses suggested that <i>PRKAG3</i>, <i>ATP2A2</i>, and <i>PPARGC1A</i> might play important roles in myofiber composition. The function of <i>PPARGC1A</i> gene was further validated. <i>PPARGC1A</i> mRNA expression levels were higher in SOL than in EDL muscles throughout the early postnatal development stages. In myoblast cells, shRNA knockdown of <i>PPARGC1A</i> significantly inhibited some muscle development and transition-related genes, including <i>PPP3CA</i>, <i>MEF2C</i>, and <i>SM</i> (<i>P</i> < 0.01 or <i>P</i> < 0.05), and significantly upregulated the expression of <i>FWM</i> (<i>P</i> < 0.05). Our study demonstrates strong transcriptome differences between oxidative and glycolytic myofibers, and the results suggest that <i>PPARGC1A</i> is a key gene involved in chicken myofiber composition and transition.</p></div>