Genome-wide association study to identify genetic loci associated with gastrointestinal nematode resistance in Katahdin sheep

dc.contributor.authorBecker, G. M.en
dc.contributor.authorDavenport, K. M.en
dc.contributor.authorBurke, Joan M.en
dc.contributor.authorLewis, R. M.en
dc.contributor.authorMiller, James E.en
dc.contributor.authorMorgan, James L. M.en
dc.contributor.authorNotter, David R.en
dc.contributor.authorMurdoch, Brenda M.en
dc.contributor.departmentAnimal and Poultry Sciencesen
dc.description.abstractResistance to gastrointestinal nematodes has previously been shown to be a moderately heritable trait in some breeds of sheep, but the mechanisms of resistance are not well understood. Selection for resistance currently relies upon faecal egg counts (FEC), blood packed cell volumes and FAMACHA visual indicator scores of anaemia. Identifying genomic markers associated with disease resistance would potentially improve the selection process and provide a more reliable means of classifying and understanding the biology behind resistant and susceptible sheep. A GWAS was conducted to identify possible genetic loci associated with resistance to Haemonchus contortus in Katahdin sheep. Forty animals were selected from the top and bottom 10% of estimated breeding values for FEC from a total pool of 641 sires and ram lambs. Samples were genotyped using Applied Biosystems (TM) Axiom (TM) Ovine Genotyping Array (50K) consisting of 51 572 SNPs. Following quality control, 46 268 SNPs were included in subsequent analyses. Analyses were conducted using a linear regression model in plink v1.90 and a single-locus mixed model in snp and variation suite. Genome-wide significance was determined by a Bonferroni correction for multiple testing. Using linear regression, loci on chromosomes 2, 3, 16, 23 and 24 were significantly associated at the genome level with FEC estimated breeding values, and we identified a region on chromosome 2 that was significant using both statistical analyses. We suggest a potential role for the gene DIS3L2 for gastrointestinal nematode resistance in Katahdin sheep, although further research is needed to validate these findings.en
dc.description.notesThe authors would like to thank the following for their involvement: Anna Rodriguez, Rebekka Job, Bonus Angus Farm, Birch Cove Farm, Destiny Acres, Downing Acres, Hound River Farm, Mammoth Hills Farm, USDA, ARS and Waldoview Farm. Thermo Fisher provided the genotyping for this research. This project was supported by Organic Agriculture Research and Extension Initiative grant no. 2016-51300-25723 and Hatch grant IDA01566 from the USDA National Institute of Food and Agriculture.en
dc.description.sponsorshipOrganic Agriculture Research and Extension Initiative grant from the USDA National Institute of Food and Agriculture [2016-51300-25723]; Hatch grant from the USDA National Institute of Food and Agriculture [IDA01566]en
dc.rightsCreative Commons Attribution-NonCommercial-NoDerivs 4.0 Internationalen
dc.subjectparasite resistanceen
dc.titleGenome-wide association study to identify genetic loci associated with gastrointestinal nematode resistance in Katahdin sheepen
dc.title.serialAnimal Geneticsen
dc.typeArticle - Refereeden


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