Variation in the mineralocorticoid and glucocorticoid receptors gene and proteomics implications for meat quality in cattle of Nellore breed

Abstract

Nowadays, the final meat consumer is requiring an animal production system that offers quality assurance on entire production chain and quality final product (meat). The environment and management practices have significant effects on the production of meat quality, since under conditions of stress, a series of important physiological activities is triggered, which may result in harm to animal production. Under stressful condition, adrenal hormones such as cortisol are released of the circulation and feedback in the brain through two nuclear receptors, glucocorticoid (GR) and mineralocorticoid (MR). The HPA axis is the central component of the stress system, and genetic polymorphisms of MR and GR genes have shown different activities of the HPA axis. Given this, the present study aims to (I) identify single nucleotide polymorphisms (SNPs) in MR and GR genes of Nellore cattle, (II) perform association analysis of the different polymorphisms of genes related to MR and GR with variables indicating the level of animal stress, as well as variables related to meat quality, (III) to characterize and determine the profile of meat proteins in Nelore cattle, based on the genotypes contrasting to the polymorphisms observed for MR and GR genes. This project aims to link the endocrine system, identification of animals susceptible to stress observed marker SNPs in nuclear receptors of the HPA axis and its implications for the proteolytic system involved in the conversion of muscle into meat, assessing levels of specific hormones reserves glycogen, their effects on the proteolysis of muscle proteins. (AU)