Identification of variants with regulatory potential on meat quality traits in Nellore cattle

Abstract

Nelore (Bos indicus) animals and their crosses. Although these animals are better adapted to the tropical climate, they have meat with less intramuscular fat and tenderness compared to animals of taurine origin. The expression of genes potentially associated with beef quality may present distortions concerning the additive model, a model universally adopted in the predictions of animal genetic value, affecting the efficiency of the selection process. When a gene has Allele-Specific Expression (ASE), its expression is unbalanced, favoring an allele, and, if influenced by the parental effect, genomic imprinting occurs. Epigenetic and cis-regulatory mechanisms may be responsible for these patterns when the regulatory SNP is heterozygous. Thus, to analyze the implication of ASE on Nellore breeding, this study will directly associate it with meat quality phenotypes and evaluate the impact of genomic imprinting by including the parental effect in the GWAS models (Parent of Origin Genome-Wide Association Studies or PO-GWAS). These results will be compared to GWAS results obtained without the inclusion of the allele parental origin. These data will be integrated with ASE SNPs from a Limousin cattle population. This latter approach aims to analyze how the pattern of expression of these variants is conserved among distinct bovine populations. The results will contribute to the identification of regulatory variants with potential application to Nelore meat quality improvement. (AU)