Abstract

Coccidiosis caused by Eimeria spp. 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 between TLR4 gene coding variants and the presence of Eimeria spp. in adult Turkish sheep were investigated. For this purpose, the presence of Eimeria spp. in fecal samples from six native Turkish sheep were determined, and approximately 1450 bp region in the 3rd exon of the ovine TLR4 gene 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 of Eimeria spp. 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 of Eimeria spp.

摘要

由艾美球虫引起的球虫病。是一种在农场动物中流行的原生动物疾病，它会造成严重的经济损失，尤其是在幼小动物中。由于对食品安全、动物福利和公共健康的关注，养殖抗病动物一直很受欢迎。Toll样受体( TLR )基因家族在参与宿主-抗原相互作用的先天免疫系统中起关键作用，因此是培育抗病动物的候选基因。在本研究中，TLR4基因编码变异与艾美球虫的存在之间可能存在遗传关联。对成年土耳其绵羊进行了调查。为此，艾美耳球虫的存在属 测定了来自六只土耳其本土绵羊的粪便样本，并对绵羊TLR4基因的第三个外显子中大约 1450 bp 的区域进行了测序。在目标区域检测到十个非同义和四个同义单核苷酸多态性 (SNP)。统计分析表明，编码亮氨酸而非苯丙氨酸 (F356L) 的^第356^位密码子的 SNP与艾美球虫的存在显着相关。发现在该位置携带至少一个亮氨酸氨基酸序列的个体存在艾美球虫属的风险高 2.3 倍。