Abstract

Recent Brazilian projects have shown promising results regarding the incorporation of molecular data as a fundamental part of the genetic evaluation processes, and several of these initiatives have already accumulated SNPs in abundance, originated mostly from commercial genotyping platforms. Current research shows that the vast majority of these commercial panels do not include causal mutations as part of its set of markers, suggesting the incorporation of sequencing techniques for including such mutations, which will likely increase the accuracy of genomic predictions, as well as the persistence of the accuracies over generations, even between breeds. This project proposes the full sequencing of 200 Nellore animals at different coverage levels, given that the animals are carefully selected via graph theory and by studying the haplotype frequencies of candidate animals for sequencing, which will minimize the re-sequencing of chromosome segments. These sequences will be used to develop an on-line database that will serve as a basis for the imputation to the sequencing level of thousands of animals already genotyped in different research projects using the Illumina HD panel (~ 800,000 SNPs). All HD genotypes will be also used as a reference population during the imputation process from lower density panels to the HD level, enabling researchers to genotype a much higher number of animals in each project, even without financial resources to compose the own reference population. This project will also investigate: i) the development of computational tools for analysis and conversion of molecular data to different genomic analyzes software, available via pipeline; ii) prediction of imputation accuracy through artificial neural networks before imputing; iii) imputation quality from HD panels to the sequence level according to different post-alignment quality controls; iv) diversity of genomic segments (CNVs, haplotypes, ROH and SNPs) within and between groups of HD genotypes submitted to the database; v) comparison of Illumina and Affymetrix HD platforms and vi) mating system incorporating genomic data. (AU)