Zabavnik Jelka, Cotman Marko, Juntes Polona, Ambrozic Ivan
Institute of Preclinical Sciences (Zabavnik, Cotman), National Veterinary Institute, Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia.
Institute of Pathology, Wild Animals, Fish and Bees (Juntes), National Veterinary Institute, Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia.
J Vet Diagn Invest. 2018 Jan;30(1):144-149. doi: 10.1177/1040638717723946. Epub 2017 Sep 14.
Sheep with valine (V) at codon 136 and glutamine (Q) at codon 171 of the prion protein gene ( Prnp) are highly susceptible to classical scrapie, whereas phenylalanine (F) at codon 141 and histidine (H) at codon 154 play a major role in the susceptibility to atypical scrapie. A TaqMan real-time PCR assay was developed to determine Prnp alleles at codons 136, 141, 154, and 171 and used in classical scrapie eradication and breeding programs adopted in Slovenia. The frequency of the most resistant genotypes ARR/ARR and ARR/ARQ increased significantly in tested animals ( n = 35,138) from 6.7 and 27.1% of the tested sheep in 2006 to 12.1 and 32.4%, respectively, in 2015. Frequencies of more susceptible genotypes ARQ/ARQ and ARQ/VRQ decreased significantly from 36.4 and 3.5% in 2006 to 31.1 and 1.8%, respectively, in 2015. The most susceptible genotype VRQ/VRQ was detected in <0.5% of tested sheep. Frequencies of alleles AFRQ and AHQ affecting the susceptibility to atypical scrapie did not change significantly. The developed assay was suitable for genotyping on a small-to-medium throughput scale and was successfully used in classical scrapie eradication, as well as for the selection of classical scrapie-resistant sheep within breeding programs in Slovenia.
朊病毒蛋白基因（Prnp）密码子136处为缬氨酸（V）且密码子171处为谷氨酰胺（Q）的绵羊对经典痒病高度易感，而密码子141处的苯丙氨酸（F）和密码子154处的组氨酸（H）在非典型痒病易感性中起主要作用。开发了一种TaqMan实时PCR检测方法，用于确定密码子136、141、154和171处的Prnp等位基因，并应用于斯洛文尼亚实施的经典痒病根除和育种计划。在测试动物（n = 35,138）中，最具抗性的基因型ARR/ARR和ARR/ARQ的频率显著增加，从2006年测试绵羊的6.7%和27.1%分别增至2015年的12.1%和32.4%。更易感基因型ARQ/ARQ和ARQ/VRQ的频率从2006年的36.4%和3.5%显著降至2015年的31.1%和1.8%。在<0.5%的测试绵羊中检测到最易感基因型VRQ/VRQ。影响非典型痒病易感性的等位基因AFRQ和AHQ的频率没有显著变化。所开发的检测方法适用于中小通量规模的基因分型，并成功应用于经典痒病的根除以及斯洛文尼亚育种计划中经典痒病抗性绵羊的选择。
