Genome-wide association studies in Murrah and Mediterranean dairy buffaloes and crossbreed

Abstract

Genomic availability tools has led to the identification of loci related to some economic importance traits, however, there are no association between multiracial populations of animals, since individuals are genetically distant, and the linkage disequilibrium between markers and QTL decays what turns hard the application of the Genome-wide Association Study (GWAS). Therefore, this project aims to estimate variance components for milk production in purebred Murrah and Mediterranean buffaloes and crossbred; and to identify chromosomal regions and possible related candidate genes to the interest traits by GWAS analysis for purebred and crossbreed animals. The data and samples use here will be obtain from an existent databank of the Animal Science Department of São Paulo State University (Unesp), Jaboticabal-SP, Brazil. The department is responsible for the Buffalo Milk-Recording Program. The phenotypic data come from two Brazilian herds located in the state of São Paulo, with information on approximately 2,000 animals born between 1,991 and 2,011. The production trait to be considered is cumulated milk yield over 305 days. To genotypes data we use the Axiom® Buffalo Genotyping Array, 90K (Affymetrix), with 706 animals genotyped. A unitary model will be applied for each purebred and posteriorly for the crossbreed animals, by the programs RELMF90 and BLUF90.