CREATION OF CLONED CATTLE LACKING THE PRION GENE

牛海绵状脑病（BSE）是一个全球性的问题，消费者的农业，工业和医疗产品。朊病毒（PrP）基因的改变形式似乎是病原体，内源性PrP基因是感染所必需的。先进细胞技术公司和马萨诸塞大学最近宣布，他们克隆出了三只转基因小牛：乔治、查理和阿尔伯特。在该项目的第一阶段，我们将扩展这项工作，通过创建牛朊病毒基因的靶向载体，PrP，并优化牛胚胎成纤维细胞电穿孔和药物选择的条件。在第二阶段，我们将创造含有同源靶向PrP基因的BEF细胞和牛。基于PrP敲除小鼠的证据，我们假设克隆的转基因动物将不能传播和感染基于朊病毒的疾病——疯牛病。因此，该项目的长期目标是创造一种牛品种，用于：(1)研究牛体内PrP的功能，(2)作为治疗神经退行性疾病的无朊病毒胚胎组织的来源，(3)提高研究和制药用牛源产品的安全性，(4)为消费者提供无朊病毒食品的来源。拟议的商业应用：含有朊病毒蛋白靶向缺失的牛可以在商业上使用(1)作为治疗神经退行性疾病的无朊病毒胚胎组织的来源(2)提高牛源产品的安全性(3)作为无朊病毒食品的来源

Bovine spongiform encephalopathy (BSE) is a world-wide problem for consumers of agriculture, industrial and medical products. An altered form of the prion (PrP) gene appears to be the causative agent, and an endogenous PrP gene is necessary for infection. Advanced Cell Technology and the University of Massachusetts recently announced the birth of three cloned transgenic calves, George, Charlie and Albert. In phase I of this project, we will extend this work, by creating a targeting vector for the bovine prion gene,, PrP, and optimizing the conditions for electroporation and drug selection in bovine embryonic fibroblasts cells. In phase II, we will create BEF cells and cattle containing a homologously-targeted PrP gene. Based on evidence from PrP knockout mice, we hypothesize that are cloned transgenic animals will be unable to both transmit and contract the prion-based disease, BSE. Thus, the long term goal of this project is to create a strain of cattle to be used: (1) to study PrP function in cattle, (2) as a source of prion-free embryonic tissue to treat neurodegenerative disease (3) to increase the safety profile of bovine derived products for research and pharmaceuticals, and (4) as a source of prion-free food products for consumers. PROPOSED COMMERCIAL APPLICATIONS: Cattle containing a targeted deletion of prion protein can be used commercially (1) as a source of prion-free embryonic tissue to treat neurodegenerative disease (2) to increase the safety profile of bovine-derived products (3) as a source of prion-free food products