The Brazilian sheep herd is increasing significantly, however the country is not self-sufficient in this meat production. Among the main factors contributing to this, we highlight those related to the herd management adopted by most producers, which employ extensive system with little or absence of technology and with the susceptibility to gastrointestinal parasites, affecting both meat quality and productivity. Therefore, the aims of this study are: (1) Perform a genome-wide association study (GWAS) for resistance to gastrointestinal parasites using SNPs markers; (2) Identify genomic regions with structural variations (Copy Number Variations - CNVs) to detect candidate genes related with the studied traits; (3) Calculate the population inbreeding levels and estimate their effects (inbreeding depression) on the characteristics studied by runs of homozygosity (ROH). Will be evaluated about 1000 Santa Inês sheep breed from eight farms of São Paulo state, located in Ribeirão Preto, Franca, São Carlos and Campinas. These animals were used in previous projects: Research Project nº12/15982-0 and 16/14522-7, technical support scholarships TT3 nº13/04302-1 and nº14/04169-2, and process 18/13050-0 where phenotypic measurements of the indicators resistance to endoparasites traits were carried out: conjunctiva staining score (CSS) fecal eggs count (FEC), packed cell volume (PCV), and coproculture (%H) used to measure the percentage of Haemonchus contortus endoparasites. The genotyping will be performed with the Ovine SNP50 Genotyping BeadChip (Illumina). Functional enrichment analyzes will be carried out from the regions identified by GWAS and the CNV regions, using the DAVID software (v.6.7). With this project it is expected to know the estimates of genetic parameters related to the characteristics of gastrointestinal worms resistance to conduct genetic improvement programs including these characteristics as a selection objective; evaluate the gain in accuracy of prediction of genetic / genomic values using information from SNPs markers in genomic prediction models compared to traditional models; evaluate the need to control the level of inbreeding using genomic information; and to characterize genomic regions associated with these characteristics in order to identify candidate genes.
News published in Agência FAPESP Newsletter about the scholarship: