NR ATPX
AU Ligios,C.; Attene,S.; Maestrale,C.; Bandino,E.; Nonno,R.; Santucciu,C.; Zucca,R.; Barba,D.; Agrimi,U.; Vaccari,G.
TI Variable risk of the AHQ allele in scrapie-affected flocks of sarda breed sheep
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Pathogenesis PATH-34
PT Konferenz-Poster
AB
The PrP allele AHQ is commonly classified in R3 risk group, with a lower susceptibility to scrapie than the ARQ allele. In Sarda breed, in which the VRQ allele is extremely rare, only sheep with the ARQ/ARQ, ARQ/AHQ and AHQ/AHQ genotypes have been described with scrapie. Aim of this work was to investigate the risk of the AHQ in comparison with the ARQ allele in a number of Sarda sheep flocks affected by scrapie. We carried out a case-control study on 121 scrapie-infected sheep and 3,819 flock-mates negative controls belonging to 13 different flocks. Sheep were classified as infected when PrPsc was found at the level of brain or lymphoid tissues.
We included in group A the flocks (n=2) in which the majority of scrapie-infected sheep carried at least one AHQ allele (12 out of 18 = 66.6%), while in group B the flocks (n=11) in which most scrapie-infected sheep carried the ARQ/ARQ genotype and only few had the AHQ allele (5 out of 103 = 4.8%). Genetic analysis of flock-mates negative controls showed that the mean frequencies of the ARQ and AHQ alleles were, respectively, 42.3% and 7.6 % in group A, while were 53.8% and 3.2% in group B.
Logistic analysis demonstrated a higher risk of the AHQ allele in flocks of group A. In contrast, the AHQ allele appears to have in group B the same risk as the ARQ allele.
Further investigations are in progress to clarify if the variable risk of the AHQ allele observed in flocks of Sarda sheep is imputable to genetic factors different from polymorphisms at 136, 154 and 171 codons or to strain-related effects.
IN Auf Sardinien gibt es nur wenige Schafe mit dem Prionproteinallel VRQ und Scrapie kam bisher nur in Schafen mit den Allelen AHQ und ARQ vor. Mit statistischen Methoden ließ sich für die sardischen Fälle nicht klären, welches dieser beiden Allele mit dem größeren Scrapie-Risiko verbunden ist.
AD C.Ligios, S.Attene, C.Maestrale, E.Bandino, C.Santucciu, R.Zucca, Istituto Zooprofilattico Sperimentale della Sardegna, Italy; R.Nonno, D.Barba, U.Agrimi, G.Vaccari, Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Italy
SP englisch
PO Deutschland