PSV-B-21 Genome-Wide Analysis of Sheep Artificially or Naturally Infected with Gastrointestinal Nematodes

Abstract Gastrointestinal nematodes (GIN) are detrimental to the health and productivity of sheep across world, necessitating genetic selection for improved GIN resistance. In this study, we used genomic analyses across- within- two important breeds in United States (US), Rambouillet Dorper, investigate physiological mechanisms associated with Genomic data were evaluated from experiments where lambs challenged GIN, either a natural environment or artificially. Lambs genotyped Axiom™ Ovine Genotyping Array (50K) 42,608 single nucleotide polymorphisms (SNP) remaining following quality control minor allele frequency variant call rate. experiment 1, fecal egg count (FEC) was collected four- eight-month-old Dorper (n=188 total) exposed on pasture. Using Plink v1.9, genome-wide association study (GWAS) identified significant SNP (P < 6.0e-5) an increase decrease FEC chromosomes 2, 3, 4, 12, 15 20. Experiment (n=77) inoculated 10,000 Haemonchus contortus L3 larvae packed-cell volume (PCV) recorded. An ensuing GWAS 2.0e-5) 5, 7, 16, 17 23 high low chromosome 10 decreased PCV. Multiple genes proximity SNP, including PIK3 subunits both experiments. Pathway analysis reported genes, PIK3, IMP4, NDST3, MRPL22, HSPA2, TGFA, TGFBR1 RUNX1 revealed involvement tissue repair, T-cell differentiation cytokine signaling more resistant GIN. Results contribute underpinnings host response US, providing foundation future animals H. infection.