Association between ovine Toll-like receptor4 (TLR4) gene coding variants and presence ofeimeria spp. ın naturally infected adult Turkishnative sheep

Abstract

Coccidiosis caused by Eimeria spp. is a protozoan disease prevalent in farm animals, and itis responsible for serious economic losses especially in young animals. It has been popularto breed disease-resistant animals due to the concern about food safety, animal welfare,and public health. Toll-like receptor (TLR) gene family plays a key role in the innate immunesystem participating in host-antigen interaction, therefore, they are candidate genes forbreeding disease-resistant animals. In the present study, possible genetic associationsbetween TLR4 gene coding variants and the presence of Eimeria spp. in adult Turkish sheepwere investigated. For this purpose, the presence of Eimeria spp. in fecal samples from sixnative Turkish sheep were determined, and approximately 1450 bp region in the 3rd exonof the ovine TLR4 gene was sequenced. Ten nonsynonymous and four synonymous singlenucleotide polymorphisms (SNPs) were detected in the targeted region. Statistical analysesrevealed that the SNP at the codon at 356th position encoding Leucine instead ofPhenylalanine (F356L) was significantly associated with the presence of Eimeria spp. It wasfound that the individuals carrying at least one Leucine amino acid sequence at this pos-ition have 2.3-fold more risk for the presence of Eimeria spp.