NR AXYD
AU Vaccari,G.; D'Agostino,C.; Nonno,R.; Rosone,F.; Conte,M.; Di Bari,M.A.; Chiappini,B.; Esposito,E.; De Grossi,L.; Giordani,F.; Casalone,C.; Marcon,S.; Morelli,L.; Agrimi,U.
TI Genetic Susceptibility of Sarda Breed Sheep to Experimental Inoculation of Scrapie, BSE and BASE
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Epidemiology, Risk Assessment and Transmission P04.75
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
With the aim to investigate the genetic susceptibility of Sarda breed sheep to scrapie and BSE, animals carrying major and rare PrP alleles were inoculated intracerebrally (i.c.) and maintained under observation until the development of clinical signs. Sheep succumbed to scrapie with mean incubation times of: 462±25 (ARQ/ARQ), 703±36 (ARQ/AHQ), 790 (AHQ/AHQ), 1083 (ARQ/ARH) and 1252±87 (AHQ/ARH) days post infection (d.p.i.), showing a clear gradient of susceptibility.
The BSE challenge induced the disease in ARQ/ARQ and in ARQ/ARH sheep with incubation times of 480±2 and 742±18 d.p.i., respectively. Up to now (1600 and 1100
d.p.i. for scrapie and BSE, respectively) the presence of at least one ARR allele appears to confer protection from clinical disease. Surprisingly, also single variations at codons 137 (M/T), 142 (I/K) and 176 (N/K) on the ARQ/ARQ and ARQ/AHQ backgrounds confer resistance to experimental scrapie and BSE. The susceptibility of Sarda sheep is currently under investigation also with respect to bovine amyloidotic spongiform encephalopathy (BASE) by the i.c. route. Till now (1100 d.p.i.), BASE caused disease only in ARQ/ARQ sheep with 868±95 d.p.i. survival time. Although it is too early to define the susceptibility of genotypes different from the ARQ/ARQ because of the short time elapsed after the challenge, also in this experiment sheep carrying the ARR allele as well as the AT137RQ/ARQ and
ARQK176/ARQ genotypes are still healthy.
Current strategies for the control and prevention of prion diseases in sheep are based on breeding programs for the selection of the ARR allele. Overall our data support the suitability of this approach and possibly expand the target of selection to additional alleles that may protect sheep from prion diseases.
AD G. Vaccari, C. D'Agostino, R. Nonno, M. Conte, M.A. Di Bari, B. Chiappini, E. Esposito, S. Marcon, L. Morelli, U. Agrimi, Istituto Superiore di Sanità, Italy; F. Rosone, L. De Grossi, F. Giordani, Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Italy; C. Casalone, CEA - Istituto Zooprofilattico Sperimentale del Piemonte, Italy
SP englisch
PO Schottland