Martemucci Giovanni, Iamartino Daniela, Blasi Michele, D'Alessandro Angela Gabriella
Department of Scienze Agro-Ambientali e Territoriali, Via G. Amendola 165/A, 70126 Bari, Italy.
Institute of Zootechnics, Università Cattolica del S. Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
Prev Vet Med. 2015 Dec 1;122(3):318-24. doi: 10.1016/j.prevetmed.2015.10.023. Epub 2015 Oct 31.
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.
在过去几十年里，人们对绵羊养殖中的羊瘙痒病的担忧有所增加。本研究在意大利南部的奶羊品种中开展。为了找到对羊瘙痒病具有抗性的种畜，对来自普利亚本地莱切塞和阿尔塔穆拉纳奶羊品种以及西西里科米萨纳奶羊品种整个群体的1205只动物的朊蛋白（PrP）基因进行了分析，以检测与羊瘙痒病抗性/易感性相关的第136、154和171密码子处的多态性。基于推测的杂交情况，阿尔塔穆拉纳品种被视为两个群体（阿尔塔穆拉纳 - 卡瓦和阿尔塔穆拉纳 - 克拉 - 佐埃）。总共发现了五个等位基因和十种不同的基因型。对于所有品种而言，ARQ等位基因占主导地位，其次是ARR，即对羊瘙痒病最具抗性的等位基因，其在科米萨纳品种中高度流行（50%），在本地阿尔塔穆拉纳 - 卡瓦群体中也较为常见（42.4%）。与对羊瘙痒病最高易感性相关的VRQ等位基因，在引进的科米萨纳品种中以不可忽视的水平被检测到（3.5%），在本地莱切塞品种和阿尔塔穆拉纳 - 克拉 - 佐埃群体中频率较低（0.2%），而在阿尔塔穆拉纳 - 卡瓦群体中未检测到。对羊瘙痒病具有极低易感性风险（R1）的PrP基因型频率在科米萨纳品种和阿尔塔穆拉纳 - 卡瓦群体中较高。最易感的基因型ARQ/VRQ仅在科米萨纳品种中被发现。在阿尔塔穆拉纳品种内部，阿尔塔穆拉纳 - 卡瓦和阿尔塔穆拉纳 - 克拉 - 佐埃绵羊之间存在显著差异。阿尔塔穆拉纳 - 卡瓦的特征是不存在VRQ和AHQ等位基因，且ARR/ARR基因型的频率较高（18.7%）。育种计划，主要是针对像阿尔塔穆拉纳这样的濒危品种，应该逐步开展，将对羊瘙痒病的抗性、遗传变异性的维持以及生产结合起来。
