Genome Wide Association Study (GWAS) for carcass traits of tilapia Oreochromis sp

Abstract

Genome Wide Association (GWAS) analysis will be performed in a population of Tilapia in order to verify the association between SNP's markers and important body traits. 1900 animals of the Tilapia Supra® strain, from the breeding program carried out by ACI Group S.A. (Cañas - Costa Rica), will be phenotyped (body weight and fillet yield) and genotyped. Genomic DNA will be extracted from samples of fin clips of the fish and the genotyping will be performed using a panel of SNP's 50k being developed by researchers of Aquainnovo and University of Chile together with the Affymetrix company. The quality of the obtained genotypes will be tested considering the Hardy-Weinberg Disequilibrium index, Minor Allele Frequency and genotyping rate. The level of linkage disequilibrium (r2) will be calculated to determine the markers' ability to record the phenotypic variation of the analyzed trait. The GWAS analysis will follow a linear mixed model including the fixed effects, random genetic additive effects and the random effect of the genetic marker. The values of used to verify the significant association between SNPs markers and evaluated traits will be adjusted by Bonferroni method. The proportion of the heritability and phenotypic variance explained by markers will be estimated. The approximate effect of each SNP marker will be estimated by linear regression analysis. (AU)