背景:朊病毒病,也被称为传染性海绵状脑病(TSEs)仍然是一种有害疾病,影响了几种动物。朊病毒蛋白(PRNP)基因的多态性主要决定了动物对TSE的易感性。然而,只有有限的研究检查了不同尼日利亚牲畜物种中PRNP基因的变异。因此,本研究旨在鉴定尼日利亚家畜物种(包括骆驼,狗,马,山羊,和绵羊)。我们对65头骆驼的开放阅读框(ORF)进行了测序,来自尼日利亚的31只乡村犬和12匹马,并与从公共数据库中检索到的886个人的PRNP序列进行了比较。
结果:所有994个个体被分为162个单倍型。绵羊具有最高数量的单倍型(n=54),骆驼最低(n=7)。系统发育树进一步证实了尼日利亚个体聚集到不同的物种中。我们检测到五个由G9A组成的PRNP的非同义SNP,G10A,C11G,G12C,和T669C由所有尼日利亚牲畜物种共享,处于哈代-温伯格平衡(HWE)。通过Polyphen-2程序,这五个非同义SNP中的氨基酸变化都是“良性的”。三个SNPsG34C,T699C,C738G只发生在尼日利亚的狗身上,而C16G,G502A,G503A,和尼日利亚马的C681A。此外,仅在山羊和绵羊中检测到C50T。
结论:我们的研究首次同时调查了尼日利亚家畜物种中PRNP基因的多态性,并提供了相关信息,可用于针对病毒病抗性育种的计划。
BACKGROUND: Prion diseases, also known as transmissible spongiform encephalopathies (TSEs) remain one of the deleterious disorders, which have affected several animal species. Polymorphism of the prion protein (PRNP) gene majorly determines the susceptibility of animals to TSEs. However, only limited studies have examined the variation in PRNP gene in different Nigerian livestock species. Thus, this study aimed to identify the polymorphism of PRNP gene in Nigerian livestock species (including camel, dog, horse, goat, and sheep). We sequenced the open reading frame (ORF) of 65 camels, 31 village dogs and 12 horses from Nigeria and compared with PRNP sequences of 886 individuals retrieved from public databases.
RESULTS: All the 994 individuals were assigned into 162 haplotypes. The sheep had the highest number of haplotypes (n = 54), and the camel had the lowest (n = 7). Phylogenetic tree further confirmed clustering of Nigerian individuals into their various species. We detected five non-synonymous SNPs of PRNP comprising of G9A, G10A, C11G, G12C, and T669C shared by all Nigerian livestock species and were in Hardy-Weinberg Equilibrium (HWE). The amino acid changes in these five non-synonymous SNP were all \"benign\" via Polyphen-2 program. Three SNPs G34C, T699C, and C738G occurred only in Nigerian dogs while C16G, G502A, G503A, and C681A in Nigerian horse. In addition, C50T was detected only in goats and sheep.
CONCLUSIONS: Our study serves as the first to simultaneously investigate the polymorphism of PRNP gene in Nigerian livestock species and provides relevant information that could be adopted in programs targeted at breeding for prion diseases resistance.