Abstract
From the sequencing of the bovine genome, a large number of genomic tools has become available due to rapid advancement of DNA marker technology. With this, it was proposed a variation of marker-assisted selection, called genomic selection, that uses information from single nucleotide polymorphisms (SNPs) markers distributed throughout the genome. Thus, high density beat chips have been developed, in which the genotypes are read from the signal intensity of the "spots". However, many factors can affect the reading of genotypes and genotyping errors can occur in a few SNPs and samples, which may lead to over or underestimation of SNPs effects. Nonetheless, it is possible to remove these genotyping errors using some exclusion criteria in the quality control step. However, there are differences in values of thresholds exclusion adopted for each of these criteria and whether or not there are effects of these different values in genomic analyzes. The objective of this project is evaluate the effect of different criteria for quality control of genotypes aiming to define appropriate criteria for editing data in genome-wide association studies and genome-wide selection in Nellore cattle. For this, it will be used phenotypic, genotypic, and pedigree information which come from farms that are part of the following animal breeding programs: DeltaGen, Nellore Qualitas, and CRV Paint. The animals were genotyped with the Illumina Bovine HD panel, which contains approximately 777,000 SNPs. It will be applied different levels of SNPs or samples exclusion for the different criteria. Analyses of genomic selection will be carried out using a linear model, "Best Linear Unbiased Predictor Genomic" (GBLUP), and nonlinear under Bayesian approach (BAYES Cpi). For the genome-wide association analysis, the nonlinear model under Bayesian approach (BAYES Cpi) will be used. At the end is expected to define appropriate criteria for genotypes edition.
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