Derivation of a scrapie-free sheep flock from the progeny of a flock affected by scrapie |
| |
| Authors: | Foster J McKenzie C Parnham D Drummond D Goldmann W Stevenson E Hunter N |
| |
| Institution: | Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh. |
| |
| Abstract: | The Cheviot flock at the Institute for Animal Health's Neuropathogenesis Unit (npu) has endemic scrapie, which affects primarily vrq/vrq sheep and at high frequency. A new flock with a full range of PrP genotypes, including the highly susceptible vrq/vrq, has been produced on a separate site, from animals in the npu breeding flock, and it remains scrapie-free after eight years. In contrast, in a parallel flock at the npu farm, scrapie has reappeared after five years, although the animals were kept in separate accommodation from the scrapie-affected sheep. During this time the npu breeding flock continued to have scrapie cases. Although it is known that highly susceptible sheep can remain free of infection in a clean environment, this is the first report of the infection being removed successfully from the bloodlines of scrapie-affected sheep. The results confirm that scrapie is not a genetic disease dependent only on the PrP gene sequence, but requires both genetic susceptibility and an infectious agent. |
| |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ |
|
