Abstrakt: |
Previous studies on mammals showed that peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) played a prominent role in regulating muscle fiber type transition and composition. However, the role of PGC-1α in chicken muscle has seldom been explored. To investigate the effect of PGC-1α on chicken skeletal muscles in this study, the PGC-1αgene was overexpressed or silenced in chicken primary myoblasts by using lentivirus, and then the effects of the PGC-1αgene overexpression and knockdown on the mRNA expression profile of genes related to myofiber type specificity were examined during fiber formation. The results showed that overexpression of PGC-1αfrom proliferation to differentiation was accompanied by the up-regulated expression of Pax7, MyoD, and CnAα, which was significantly (P<0.01) increased after one day of transfection (1I). The enhancement of MyoG, MEF2c, and MyHC SMexpression lagged, which was improved significantly (P<0.01) after four days of transfection (1I3D). Overexpression of PGC-1αdecreased (P<0.01) the MyHC FWMexpression after four days of transfection (1I3D), and it had no significant impact (P>0.05) on the expression of CnB1, NFATc3, and MyHC FRMduring myofiber formation. The effective silence (P<0.01) of PGC-1αby lentivirus mediating short hairpin RNA (shRNA) was detected after four days of transfection (1I3D) in cultures, and the lack of its function in chicken primary myoblasts significantly (P<0.01) down-regulated the expression of Pax7, MyoD, CnAα, MyoG, MEF2c, and MyHC SM, significantly (P<0.01) up-regulated the expression of MyHC FWM, and had no significant impact (P>0.05) on the expression of CnB1, NFATc3, and MyHC FRM. These results indicated that the role of PGC-1αin regulating the fiber type specificity of chicken skeletal muscles might be similar to that in mammals, which interplayed with key genes related to myocyte differentiation and calcineurin signaling pathway. |