Neuronal accumulation of abnormal prion protein in sheep carrying a scrapie-resistant genotype (PrPARR/ARR).
The susceptibility of sheep to scrapie infection is influenced by prion gene alleles, which are modulated by polymorphic variations corresponding to amino acid positions 136, 154 and 173 of the prion protein (PrP). As no unquestioned report of a diseased sheep carrying homozygous alleles encoding alanine, arginine and arginine (PrPARR) at these sites has been published to date, sheep of this genotype are believed to be scrapie resistant. After the introduction of large-scale rapid testing for scrapie, a number of so-called 'atypical' scrapie cases have been found in Germany and elsewhere. Among those cases were two supposedly scrapie-resistant sheep. Brain samples from these animals tested positive for abnormal PrP (PrPSc) in one of four rapid tests available. Moreover, scrapie-associated fibril (SAF)-immunoblotting and immunohistochemistry, which are the generally accepted diagnostic techniques for scrapie, revealed prominent PrPSc deposition in the cerebellum. SAF immunoblotting also revealed PrPSc deposition in the obex, frontal cortex and brainstem. Transmission experiments to investigate the infectivity of scrapie propagated from these sheep have been initiated.
Federal Research Centre for Virus Diseases of Animals, Institute for Novel and Emerging Infectious Diseases, Boddenblick 5a, 17493 Greifswald - Insel Riems, Germany.
Anne
A
Buschmann
Department of Animal Breeding and Genetics, Justus-Liebig-University Gießen, Ludwigstraße 21B, 35390 Gießen, Germany.
Gesine
G
Lühken
Federal Research Centre for Virus Diseases of Animals, Institute for Novel and Emerging Infectious Diseases, Boddenblick 5a, 17493 Greifswald - Insel Riems, Germany.
Julia
J
Schultz
Department of Animal Breeding and Genetics, Justus-Liebig-University Gießen, Ludwigstraße 21B, 35390 Gießen, Germany.
G
G
Erhardt
Federal Research Centre for Virus Diseases of Animals, Institute for Novel and Emerging Infectious Diseases, Boddenblick 5a, 17493 Greifswald - Insel Riems, Germany.
Martin H
MH
Groschup
D000409:Alanine / Q000235:genetics; D000483:Alleles; D000818:Animals; D001120:Arginine / Q000235:genetics; D001921:Brain / Q000378:metabolism*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005858:Germany; D006720:Homozygote; D015151:Immunoblotting; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism; D018622:PrP 27-30 Protein / Q000378:metabolism; D018620:PrPSc Proteins / Q000235:genetics* / Q000378:metabolism; D012608:Scrapie / Q000235:genetics* / Q000378:metabolism; D012756:Sheep / Q000235:genetics* / Q000378:metabolism
D018620:PrPSc Proteins; D018622:PrP 27-30 Protein; D001120:Arginine; D000409:Alanine