Guan Feng, Pan Lei, Li Jie, Tang Hong, Zhu Cheng, Shi Guoqing
College of Life Sciences, China Jiliang University, Hangzhou, 310018, People's Republic of China.
Virus Genes. 2011 Aug;43(1):147-52. doi: 10.1007/s11262-011-0609-5. Epub 2011 May 10.
It is well known that scrapie is a fatal, neurodegenerative disease in sheep and goat, which belongs to the group of transmissible spongiform encephalopathies (TSEs) or prion diseases. It has been confirmed that the polymorphisms of prion protein gene (PRNP) at codons 136, 154, and 171 have strong relationship with scrapie in sheep. In the present study, nine polymorphisms of PRNP at codons 136, 154, and 171 and other six loci (at codons 101, 112, 127, 137, 138, and 152) were detected in 180 Chinese Hu sheep. All the alleles at codons 136, 154, and 171 have been identified and resulted in three new genotypes. The frequencies of predominant alleles were 85% (A136), 99.40% (R154), and 37.78% (Q171), respectively. The predominant haplotype ARQ has a relatively high frequency of 57.77%. The frequencies of dominant genotypes of ARR/ARQ and ARQ/ARQ were 30 and 26.67%, respectively. Three new found genotypes named ARQ/TRK, ARQ/TRR, and TRR/TRQ had the same lower frequencies (0.56%). The relationship of PRNP genotype with scrapie risk and litter size showed that the predominant genotypes are corresponded to the risk score of R(1) (1.67%), R(2) (32.22%), and R(3) (42.22%). Just at the first parity, the individuals with ARH/ARH genotype had significantly larger litter size than the mean value and those with ARQ/ARQ and ARR/ARQ genotypes. In short, this study provided preliminary information about alleles and genotypes of PRNP in Chinese Hu sheep. It could be concluded that Hu sheep has a low susceptibility to natural scrapie, and the predominant PRNP genotype at least has no significant effect on litter size.
众所周知,羊瘙痒病是绵羊和山羊的一种致命性神经退行性疾病,属于传染性海绵状脑病(TSEs)或朊病毒疾病。已经证实,朊病毒蛋白基因(PRNP)第136、154和171密码子的多态性与绵羊的羊瘙痒病密切相关。在本研究中,对180只中国湖羊检测了PRNP第136、154和171密码子的9种多态性以及其他6个位点(第101、112、127、137、138和152密码子)。已鉴定出第136、154和171密码子的所有等位基因,并产生了三种新的基因型。优势等位基因的频率分别为85%(A136)、99.40%(R154)和37.78%(Q171)。优势单倍型ARQ的频率相对较高,为57.77%。ARR/ARQ和ARQ/ARQ优势基因型的频率分别为30%和26.67%。新发现的三种基因型ARQ/TRK、ARQ/TRR和TRR/TRQ的频率相同且较低(0.56%)。PRNP基因型与羊瘙痒病风险和产仔数的关系表明,优势基因型对应的风险评分分别为R(1)(1.67%)、R(2)(32.22%)和R(3)(42.22%)。仅在第一胎时,ARH/ARH基因型的个体产仔数显著大于平均值,以及具有ARQ/ARQ和ARR/ARQ基因型的个体。简而言之,本研究提供了中国湖羊PRNP等位基因和基因型的初步信息。可以得出结论,湖羊对自然羊瘙痒病的易感性较低,且PRNP优势基因型至少对产仔数没有显著影响。