Association between Copy Number Variation (CNVs) of DNA segments in the Santa Inês sheep genome with resistance to endoparasites traits

• Grant number: 20/15760-4
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): June 01, 2021
• Effective date (End): November 30, 2022
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Claudia Cristina Paro de Paz
• Grantee: Marina Bueno Mioto
• Host Institution: Instituto de Zootecnia. Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Nova Odessa , SP, Brazil
• Associated research grant: 16/14522-7 - Genomic studies associated with resistance to endoparasites traits in Santa Inês sheep, AP.TEM

Abstract

Sheep farming is growing in Brazil, but the country is not yet self-sufficient to attend the demand of the domestic market, resorting to imports. Health is one of the main factors that hinder efficiency in production, since the management adopted it is majority inadequate, intended for subsistence, in an extensive system and without investments in technology, increasing the susceptibility of sheep to gastrointestinal nematodes. Another point is the excessive use of anthelmintics that contributed to the increase of resistant nematodes, making it necessary to find alternative means of control. The methods used for the identification of animals with infections caused by helminths are fecal eggs counts (FEC), color of ocular conjunctiva (COC), packed cell volume (PCV), total plasmatic protein (TPP) and coproculture (% C) for parasite identification. In this project, 1,150 Santa Inês sheep were genotyped with the Ovine SNP50 Genotyping BeadChip (Illumina) to identify regions with variations in the number of copies in the DNA segments (CNVs) associated with the parasitic resistance traits CNVs will be identified using the PennCNV software and samples with a call rate below 95% will be discarded. SNPs with a frequency less than 90%, mapped on sex chromosomes or with no position in the reference genome Oar_v3.1 will also be excluded. The objective for the detection of CNV regions is the selection of animals with traits of resistance to gastrointestinal endoparasites using genomic information, aiming to decrease the costs with drugs, the losses in the production system. (AU)