Expression of genes related to mitochondrial function in cattle nellore extreme for residual feed intake

Abstract

The beef cattle industry is an activity of great social and economic importance in Brazil and create animals effectively makes the activity more profitable to farmers. One of the more expensive components involved in animal production is the cost of food. Therefore, many indices have been proposed in order to improve feed efficiency. Recently began the study of residual feed intake, which is estimated, considering the difference between actual consumption and the amount of food the animal should eat based on their average weight, which can identify most animals efficient without selection for weight at adulthood. Recent studies have demonstrated mitochondrial function as a factor of great influence in the residual feed intake, because the mitochondria are responsible for producing 90% of the energy required by cells coming from the food and breathing through the process of oxidative phosphorylation. Analyze genes involved in mitochondrial function becomes an alternative to identify molecular markers associated with increased feed efficiency. The uncoupling proteins (UCPs) are located in the inner membrane of mitochondria, and among them are the UCP-2 and UCP-3, which act on the control of adaptive thermogenesis and control of production of reactive oxygen species in mitochondria. The protein TFAM (mitochondrial transcription factor A) is involved in transcription of mitochondrial DNA and is a key factor directly involved in mitochondrial DNA replication. The PGC-1 can induce mitochondrial biogenesis, thermogenesis and respiration. This work will analyze the gene expression of UCP-2 gene, UCP-3, TFAM and PGC-1 in muscle tissue, liver and adipose two groups of Nellore with contrasting values of residual feed intake from a study by Research Centre Beef Cattle Institute of Animal Science Sertãozinho, to evaluate the relationship of these genes with residual feed intake. (AU)