Yuzbasiyan-Gurkan V, Krehbiel J D, Cao Y, Venta P J
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824-1314, USA.
Am J Vet Res. 1999 Jul;60(7):884-7.
To develop new and improved tests to detect alleles at codons 136 and 171 of the ovine prion protein locus and to evaluate the frequency of these alleles.
159 Suffolk sheep belonging to 3 flocks.
Polymerase chain reaction (PCR) analysis that contained diagnostic restriction site variation for each allele were developed for the relevant gene regions. Alleles were determined by analyzing DNA isolated from buccal swab specimens or blood samples.
At codon 136, frequencies of the alanine and valine alleles were found to be 97 and 3%, respectively. At codon 171, frequencies of the glutamine, arginine, and histidine alleles were found to be 57, 41, and 2%, respectively.
Little variation was detected in codon 136, whereas noteworthy variation was found in codon 171; > 40% of the alleles at this locus coded for glutamine. Because the glutamine allele at codon 171 confers susceptibility to scrapie, reduction of its frequency is of importance to management of sheep flocks.
Genotyping of sheep, using the tests reported here, should facilitate selective breeding programs designed to decrease the risk of scrapie.
开发新的改良检测方法，以检测绵羊朊病毒蛋白基因座第136和171密码子处的等位基因，并评估这些等位基因的频率。
来自3个羊群的159只萨福克羊。
针对相关基因区域，开发了包含每个等位基因诊断性限制性位点变异的聚合酶链反应（PCR）分析方法。通过分析从口腔拭子样本或血液样本中分离的DNA来确定等位基因。
在第136密码子处，丙氨酸和缬氨酸等位基因的频率分别为97%和3%。在第171密码子处，谷氨酰胺、精氨酸和组氨酸等位基因的频率分别为57%、41%和2%。
在第136密码子处检测到的变异很少，而在第171密码子处发现了显著变异；该基因座>40%的等位基因编码谷氨酰胺。由于第171密码子处的谷氨酰胺等位基因使绵羊易患羊瘙痒病，降低其频率对羊群管理很重要。
使用本文报道的检测方法对绵羊进行基因分型，应有助于设计旨在降低羊瘙痒病风险的选择性育种计划。
