1. Association study reveals Th17, Treg, and Th2 loci related to resistance to Haemonchus contortus in Florida Native sheep1.
- Author
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Estrada-Reyes ZM, Rae O, Postley C, Jiménez Medrano MB, Leal Gutiérrez JD, and Mateescu RG
- Subjects
- Animals, Body Weight, Feces parasitology, Female, Florida, Genotyping Techniques veterinary, Haemonchiasis immunology, Haemonchiasis parasitology, Male, Parasite Egg Count veterinary, Phenotype, Sheep, Sheep Diseases parasitology, T-Lymphocytes, Regulatory immunology, Disease Resistance genetics, Genome-Wide Association Study veterinary, Haemonchiasis veterinary, Haemonchus immunology, Sheep Diseases immunology
- Abstract
The aim of this study was to identify for the first time single nucleotide polymorphisms (SNPs) associated with Haemonchus contortus resistance in Florida Native sheep, using a targeted sequencing approach. One hundred and fifty-three lambs were evaluated in this study. At the start of the trial, phenotypic records for fecal egg count (FEC), FAMACHA score, body condition score (BCS), and weight were recorded and deworming of sheep with levamisole (18 mg/kg of body weight) was performed. Ten days post-deworming (baseline) and 28 d post-baseline, a full hematogram of each sheep was obtained and FEC, FAMACHA score, BCS, and weight were assessed. Average daily gain was calculated at the end of the trial. Out of 153 animals, 100 sheep were selected for genotyping using a targeted sequencing approach. Targeted sequencing panel included 100 candidate genes for immune response against H. contortus. SNPs were discarded if call rate <95% and minor allele frequency ≤0.05. A mixed model was used to analyze the response variables and included the identity by state matrix to control for population structure. A contemporary group (age, group, and sex) was included as fixed effect. Bonferroni correction was used to control for multiple testing. Eighteen SNPs on chromosomes 1, 2, 3, 4, 6, 7, 11, 15, 18, 20, 24, and 26 were significant for different traits. Our results suggest that loci related to Th17, Treg, and Th2 responses play an important role in the expression of resistant phenotypes. Several genes including ITGA4, MUC15, TLR3, PCDH7, CFI, CXCL10, TNF, CCL26, STAT3, GPX2, IL2RB, and STAT6 were identified as potential markers for resistance to natural H. contortus exposure. This is the first study that evaluates potential genetic markers for H. contortus resistance in Florida Native sheep., (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2019
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