From: TSS ()
Subject: scrapie or BSE in sheep, or both ???
Date: April 19, 2007 at 8:21 am PST
Molecular behaviours of "CH1641-like" sheep scrapie isolates in ovine transgenic mice (TgOvPrP4)
Thierry BARON* and Anne-Gaëlle BIACABE
Agence Française de Sécurité Sanitaire des Aliments - Lyon, Unité ATNC, Lyon, France
* To whom correspondence should be addressed. Email: email@example.com .
Molecular analyses of the protease-resistant prion protein (PrPres) from a few natural scrapie isolates showed by Western blot some partial similarities with that observed in experimental ovine BSE. They showed a low apparent molecular mass of unglycosylated PrPres, although diglycosylated PrPres was less abundant than in ovine BSE. The prototype of such cases is the CH1641 experimental scrapie isolate. We analysed PrPres molecular features from 3 French natural isolates, in comparison with CH1641 and BSE, after transmission of the disease in ovine transgenic mice (TgOvPrP4). One of these isolates (TR316211) behaved as the CH1641 isolate, with similar PrPres features in mice compared to the sheep brain. From two other isolates (O100 and O104), two distinct PrPres phenotypes were identified in mouse brains, with either high (h-type) or low (l-type) apparent molecular masses of unglycosylated PrPres, this last one being similar to that observed with CH1641, TR316211 or BSE. Both phenotypes could be found in variable proportions in the brain of the individual mice. In contrast with BSE, l-type PrPres also showed lower levels of diglycosylated PrPres. From one of these cases (O104), second passage in mice was performed from two mice with distinct PrPres profiles. This showed a partial selection of the l-type phenotype in mice infected with a mouse brain with predominant l-type PrPres, and this was accompanied by a significant increase in the proportions of the diglycosylated band. These results are discussed in relation with the diversity of scrapie and BSE strains. .......
Prion protein alleles showing protective effect on the susceptibility of sheep to scrapie and BSE