PrP genotype frequencies in German breeding sheep and the potential to breed for resistance to scrapie
PrP genotype frequencies in German breeding sheep and the potential to breed for resistance to scrapie
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DOI：
10.1136/vr.149.12.349
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发表时间：
2001-09-22
影响因子：
2.2
通讯作者：
Distl, O
中科院分区：
文献类型：
--
作者：
Drögemüller, C;Leeb, T;Distl, O
羊瘙痒病的遗传易感性与绵羊朊蛋白（PrP）基因三种不同密码子的多态性有关（136，154，171）。与羊瘙痒病相关的PrP基因型研究揭示了纯合PrPARR/PrPARR动物的抗性以及受羊瘙痒病影响的羊群中PrPVRQ/PrPVRQ和PrPVRQ/PrPARQ动物的高风险。因此，PrPARR/PrPARR基因型的选择可能为控制临床瘙痒症提供策略。对来自北方德国15个不同品种的1361只德国种羊进行了基因型测定。除野生型PrPARQ等位基因外，还发现至少4个相互排斥的等位基因变异体，其中以texel绵羊PrP基因变异最大，共发现14种PrP基因型，在重要的肉用品种萨福克羊、德国白头羊和德国黑头羊中，PrPARR等位基因占优势，在这些品种中，在四代内培育抗羊瘙痒病的纯种鸡群似乎是一个可行的选择。在texel羊，德国美利奴，德国牛奶和德国土地绵羊品种，PrPARR等位基因的频率要低得多，并在几个品种没有纯合子公羊可用于育种目的。在这些品种中，育种策略将取决于可获得的异型公羊的数量，但抗性谱系群可以在9代内获得。
Genetic susceptibility to scrapie is associated with polymorphisms in three different codons of the ovine prion protein (PrP) gene (136,154,171). Studies of PrP genotypes linked to scrapie have revealed the resistance of homozygous PrPARR/PrPARR animals and the high risk of PrPVRQ/PrPVRQ and PrPVRQ/PrPARQ animals in scrapie-affected flocks. The selection of PrPARR/PrPARR genotypes may therefore provide a strategy for controlling clinical scrapie. The genotypes of 1361 German breeding sheep from 15 different breeds in northern Germany were determined. Apart from the wildtype allele PrPARQ, at least four mutually exclusive allelic variants were found. The greatest variability within the PrP gene was encountered in texel sheep, in which 14 PrP genotypes were found. in the important meat breeds, Suffolk, German whiteheaded mutton and German blackheaded mutton, the PrPARR allele was predominant, and in these breeds the breeding of scrapie-resistant pedigree flocks within four generations seems to be a feasible option. In the texel sheep, the German merino, the German milk and the German land sheep breeds, the frequency of the PrPARR allele was much lower, and in several breeds no homozygous rams were available for breeding purposes. in these breeds the breeding strategy would depend on the number of heteroxygous rams available, but resistant pedigree flocks could be achieved within nine generations.