Identification and characterization of genes associated with intramuscular fat deposition and composition in the Nellore breed

Abstract

Fat deposition and composition are determined by many genes that participate directly or indirectly in adipogenesis and lipid metabolism. The selection of animals with content and fat composition suitable for the consumer is complex due to the difficult of measuring these characteristics, the moderate heritability and the lack of the genes involved. In the last decade a major advance in the bovine genome resulted in the complete sequencing of the genome and the development of chips for high-density SNP. This project aims to identify genes and allelic variants associated with the percentage and composition of intramuscular fat (IMF) in Nellore cattle. Four hundred fifty seven animals are being used to evaluate the Nellore content of total lipids of Longissimus dorsi (LD), genotyping chip with high density of SNPs (SNP800 Illumina BeadChip), fatty acid profile and association study of SNPs to find genes by position associated with phenotypic characteristics of interest. For the study of gene expression will be used 36 animals with extreme values for percentage of IMF. Strategies of genomic association (genome wide association studies, GWAS), sequencing messenger RNA (RNA-seq) and integrating the results of bioinformatics are being used to accomplish this objective. Analyzing all data generated is required a bioinformatics platform of analyzes of data structured and active, which is not yet found in Brazil because it is a new field. For proper completion and analysis of large amounts of data from this project we are requesting to grant a research internship abroad (BEPE) so the student can analyze the project in the Department of Animal Science of Iowa State University, USA under the guidance of Professor Dr. James Reecy, the Bioinformatics Program Coordinator of ISU. Currently, Dr. Reecy works in the field of animal genomics with the overall goals of identifying ways to increase the production of lean tissue and meat quality of cattle and to develop bioinformatics tools for genomic research. (AU)