Pdk4 Gene In Skeletal Muscle Function Discussed

The essential characteristic of biological life is metabolism. It is the incessant flow of energy and matter through a network of chemical reactions that enable the living organism to generate all kinds of activities. The metabolism is not a spontaneous reaction and is catalyzed by the enzymes. To give an insight into the molecular mechanism of postnatal development, broiler and layer chicken have been utilized as animal model because of their significant difference in skeletal muscle growth rate. So broiler needs much more energy to maintain the high muscle growth rate. Some metabolic enzyme must be differentially expressd between broiler and layer. Our lab used microarray data to analysis the differential muscle growth of broiler and layer after hatch.Pyruvate dehydrogenase kinase 4 (PDK4) plays an important role in the glycolysis. The regulation of PDC activity by PDK determines and reflects substrate preference and is critical to the 'glucose-fatty acid cycle' to maintain glucose homoeostasis. Real-time PCR demonstrated that PDK4 was differentially expressed between layer and broiler, which were consistent with the result of microarray. We have identified a negative correlation for muscular PDK4 gene expression with the postnatal rapid growth of broiler and the Pyruvate dehydrogenase (PDH) activity during the post-hatch development is coincident with its mRNA expression pattern, but not in layer. The PDK4 expression pattern and the PDH enzyme activity during the muscle cells differentiation in vitro indicated that PDK4 gene was partially involved in the broiler rapid growth. Finally, to assess whether PDK4 is the direct regulator of broiler postnatal muscle growth, we investigated whether PDK4 could affect the cell cycle. Our data demonstrate that PDK4 itself was not enough to initiate the rapid muscle growth of broiler. However, the correlation between the PDK4 expression level of broiler and its growth rate also told us that PDK4 was the genetics selected gene which contributed to the broiler postnatal growth. Overall, our results first indicate that PDK4 gene expression is correlated to the broiler muscle growth. Our researches try to elucidate the possible role of PDK4 in the broiler muscle rapid growth. And the researches would help to explain the big difference between broiler and layer postnatal muscle development.