Association between ovine toll-like receptor 4 (TLR4) gene coding variants and presence of eimeria spp. in naturally infected adult Turkish native sheep

Abstract

Coccidiosis caused byEimeriaspp. is a protozoan disease prevalent in farm animals, and it is responsible for serious economic losses especially in young animals. It has been popular to 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 immune system participating in host-antigen interaction, therefore, they are candidate genes for breeding disease-resistant animals. In the present study, possible genetic associations betweenTLR4gene coding variants and the presence ofEimeriaspp. in adult Turkish sheep were investigated. For this purpose, the presence ofEimeriaspp. in fecal samples from six native Turkish sheep were determined, and approximately 1450 bp region in the 3rd exon of the ovineTLR4gene was sequenced. Ten nonsynonymous and four synonymous single nucleotide polymorphisms (SNPs) were detected in the targeted region. Statistical analyses revealed that the SNP at the codon at 356(th)position encoding Leucine instead of Phenylalanine (F356L) was significantly associated with the presence ofEimeriaspp. It was found that the individuals carrying at least one Leucine amino acid sequence at this position have 2.3-fold more risk for the presence ofEimeriaspp.