Identificação de CNVRs associadas ao teor de colesterol na carne de bovinos da raça Nelore

Abstract

In Brazil, Nellore breed animals and their crosses represent over 80 % of all the animals that compose the beef herd. This is due to their excellent adaptation to tropical environment, resistance to endo and ectoparasites and efficiency in food conversion. In addition, its meat is characterized by low content of intramuscular fat (marbling) and they present a homogenous distribution of fat covering the carcass, which are traits valued on beef market. However, the ingestion of high levels of fat is harmful to human health. The excess of cholesterol, for example, is a factor associated to cardiovascular diseases and metabolic syndromes. Thus, our objective was the identification of copy number variation regions (CNVRs) associated with the cholesterol content in beef, which can be helpful for a more efficient selection of animals that produce meat with better lipid composition. For that, biotechnologies developed from the DNA sequencing, such as single nucleotide polymorphisms (SNPs) chips were used to identify CNVs and CNVRs. The phenotypic data were measured in 615 animals, being the samples genotyping performed in only 407 animals by Infinium platform with Illumina Bovine beadchip HD® composed of 777,962 SNPs. The genotypes were defined by GenomeStudio v2011.1. software. The CNVs identification was performed by the PennCNV program and the association between CNVRs with cholesterol content was done by linear regression using the CNVRuler program. Four CNVRs were detected with favorable association with the cholesterol deposition in Nellore beef, that means, promoting a reduction of it. In addition, genes previously described in the bovine genome were identified in these CNV regions and they were associated with lipid metabolism in humans.