Identification and characterization of euchromatic regions associated with gene expression and intramuscular fat in nelore cattle

Abstract

In eukaryotes, DNA is organized along with histones in nucleoproteins complexes known as nucleosomes. Chromatin exists in two forms: euchromatin, lightly condensed structure, and therefore more easily transcribed region, and heterochromatin, highly condensed structure and region typically not transcribed. In euchromatin form, transcription factors have free access to nucleosome-depleted DNA regions, while in heterochromatin the transcription factors can not access the DNA for activate or repress genic expression, which suggests that the compaction degree of chromatin interfere in gene expression regulation and the nucleosomes acts as silencer genic. Genome Wide-Association (GWAS) experiments have been associating Quantitative Trait Locus (QTL) regions to intergenic regions indicating the presence of causal mutations in regulatory regions. The aim of this project is to find euchromatic regions revealing regulatory sites in Nellore breed genome and correlate them with expression Quantitative Trait Loci (eQTL) regions previously identified, candidates to the Longissimus dorsi muscle's regulation of the deposition and composition of intramuscular fat, refining causal mutations search. This project is linked to the thematic project "Molecular bases of meat quality in Nelore cattle" which results will contribute to the knowledge of the transcription regulation in bovine Bos indicus subspecies. (AU)