|
关于养羊过程中痒病的关注在过去的几十年里有所增加。该研究是在意大利南部的乳用羊品种中进行的。为了找到选育抗痒病朊蛋白基因的动物，研究人员分析了整个乳用土著Apulian Leccese品种、Altamurana品种和Sicilian Comisana品种羊群的1205只动物的与绵羊痒病抗性/易感性相关的PrP基因密码子136，154和171的多态性。
根据推定的杂交育种，研究人员认为Altamurana品种有两个种群（Alt-Cav 和 Alt-Cra-Zoe）。研究中共发现五个等位基因和十个不同的基因型。痒病的最耐受的等位基因即ARQ等位基因在所有品种中占主导地位其次是ARR，这种基因型在Comisana（50%）和土著的Alt-Cav（42.4%）是非常普遍的。VRQ等位基因，与羊痒病具有最高的易感性相关，检测结果显示其在allocthonous Comisana中不是轻微水平（3.5%），在土著Leccese和Alt-Cra-Zoe中的频率较低（0.2%），而在Alt-Cav中不存在。对羊痒病具有非常低的易感风险的PrP基因型频率（R1）明显高于Comisana和Alt-Cav。最易感的基因型，ARQ / VRQ，只在Comisana中发现。在Altamurana品种中，Alt-Cav绵羊和Alt-Cra-Zoe绵羊之间存在显著差异。Alt-Cav的特点是VRQ和AHQ等位基因缺失而ARR / ARR基因型频率较高（18.7%）。根据以上研究结果，育种计划应主要集中在濒危品种如Altamurana绵羊，同时结合抗痒病，逐步开展遗传变异的维护和生产。
原文摘要如下：
PrP genotype frequencies and risk evaluation for scrapie in dairy sheep breeds from southern Italy
Martemucci G1, Iamartino D2, Blasi M3, D'Alessandro AG4
Abstract: Concerns regarding scrapie in sheep breeding have increased in the last few decades. The present study was carried out in dairy sheep breeds from southern Italy. In order to find breeding animals resistant to scrapie, the PrP genes of 1,205 animals from entire flocks of dairy native Apulian Leccese and Altamurana breeds, and Sicilian Comisana breed, were analysed for polymorphisms at codons 136, 154, and 171 related to scrapie resistance/susceptibility. The Altamurana breed was considered as two populations (Alt-Cav and Alt-Cra-Zoe), based on presumed cross-breeding. A total of five alleles and ten different genotypes were found. The ARQ allele was predominant for all breeds followed by ARR, the most resistant allele to scrapie, which was highly prevalent in Comisana (50%) and in native Alt-Cav (42.4%). The VRQ allele, associated with the highest susceptibility to scrapie, was detected at not negligeable levels in allocthonous Comisana (3.5%), at a low frequency (0.2%) in native Leccese and Alt-Cra-Zoe, while it was absent in Alt-Cav. The frequencies of PrP genotypes with a very low susceptibility risk to scrapie (R1) was higher in Comisana and Alt-Cav. The most susceptible genotype, ARQ/VRQ, was found only in Comisana. Within the Altamurana breed, there were notable differences between Alt-Cav and Alt-Cra-Zoe sheep. The Alt-Cav was characterised by the absence of VRQ and AHQ alleles and by the higher frequency of the ARR/ARR genotype (18.7%). Breeding programs, mainly in endangered breeds such as Altamurana, should be conducted gradually, combining resistance to scrapie, maintenance of genetic variability, and production.
Keywords: Genetic variability, Prion protein (PrP) gene, Scrapie susceptibility, Sheep
更详细内容
相关信息:
|
