Centre for Research in Endocrinology and Reproductive Sciences (CRERS), Department of Physiology and Cell Biology, University of Health Sciences (UHS), Khayaban-e-Jamia Punjab, Lahore 54600, Pakistan.
Gene. 2012 Aug 15;505(1):180-5. doi: 10.1016/j.gene.2012.05.038. Epub 2012 May 24.
Bovine spongiform encephalopathy (BSE) is a neurodegenerative prion protein misfolding disorder of cattle. BSE is of two types, classical BSE and atypical BSE which in turn is of two types, H-type BSE and L-type BSE. Both H-type BSE and L-type BSE are primarily sporadic prion disorders. However, one case of H-type BSE has recently been associated with E211K polymorphism in the prion protein gene (PRNP). Two polymorphisms in the bovine PRNP are also associated with susceptibility to classical BSE: a 23 bp insertion/deletion (indel) in the PRNP promoter region and a 12 bp indel in the first intron. No information regarding BSE susceptibility in Pakistani cattle is available. The present study aimed at achieving this information. A total of 236 cattle from 7 breeds and 281 buffaloes from 5 breeds were screened for E211K polymorphism and 23 bp and 12 bp indels employing triplex PCR. The E211K polymorphism was not detected in any of the animals studied. The 23 bp insertion allele was underrepresented in studied cattle breeds while the 12 bp insertion allele was overrepresented. Both 23 bp and 12 bp insertion alleles were overrepresented in studied buffalo breeds. Almost 90% of alleles were insertion alleles across all studied buffalo breeds. The average frequency of 23 bp and 12 bp insertion alleles across all studied cattle breeds was found to be 0.1822 and 0.9407, respectively. There were significant differences between Pakistani and worldwide cattle in terms of allele, genotype and haplotype frequencies of 23 bp and 12 bp indels. The higher observed frequency of 12 bp insertion allele suggests that Pakistani cattle are relatively more resistant to classical BSE than European cattle. However, the key risk factor for classical BSE is the dietary exposure of cattle to contaminated feedstuffs.
牛海绵状脑病（BSE）是一种牛的神经退行性朊病毒蛋白错误折叠疾病。BSE 有两种类型，经典 BSE 和非典型 BSE，而非典型 BSE 又分为 H 型 BSE 和 L 型 BSE。H 型 BSE 和 L 型 BSE 主要是散发性朊病毒疾病。然而，最近有一例 H 型 BSE 与朊病毒蛋白基因（PRNP）中的 E211K 多态性有关。牛 PRNP 中的两个多态性也与经典 BSE 的易感性有关：PRNP 启动子区域的 23 个碱基对插入/缺失（indel）和第一内含子中的 12 个碱基对插入。目前尚无关于巴基斯坦牛 BSE 易感性的信息。本研究旨在获得这些信息。使用三重 PCR 对来自 7 个品种的 236 头牛和来自 5 个品种的 281 头水牛进行了 E211K 多态性以及 23 bp 和 12 bp 插入缺失的筛选。在研究的动物中未检测到 E211K 多态性。23 bp 插入等位基因在研究的牛品种中代表性不足，而 12 bp 插入等位基因则代表性过高。在研究的水牛品种中，两个 23 bp 和 12 bp 插入等位基因都代表性过高。在所有研究的水牛品种中，几乎 90%的等位基因是插入等位基因。在所有研究的牛品种中，23 bp 和 12 bp 插入等位基因的平均频率分别为 0.1822 和 0.9407。在 23 bp 和 12 bp 插入缺失的等位基因、基因型和单倍型频率方面，巴基斯坦牛与世界其他地区的牛存在显著差异。观察到的 12 bp 插入等位基因的较高频率表明，与欧洲牛相比，巴基斯坦牛对经典 BSE 的抵抗力相对较强。然而，经典 BSE 的关键风险因素是牛对受污染饲料的饮食暴露。
