Scrapie Resistance in ARQ Sheep

Authors

W. W. Laegreid, University of Illinois at Urbana-ChampaignFollow
M. L. Clawson, U.S. Department of AgricultureFollow
M. P. Heaton, U.S. Department of AgricultureFollow
B. T. Green, U.S. Department of Agriculture
Katherine I. O'Rourke, U.S. Department of AgricultureFollow
D. P. Knowles, USDA-ARSFollow

Date of this Version

2008

Comments

Published in JOURNAL OF VIROLOGY, Oct. 2008, p. 10318–10320 Vol. 82, No. 20

Abstract

Variation in the ovine prion protein amino acid sequence influences scrapie progression, with sheep homozygous for A¹³⁶R¹⁵⁴Q¹⁷¹ considered susceptible. This study examined the association of survival time of scrapie-exposed ARQ sheep with variation elsewhere in the ovine prion gene. Four single nucleotide polymorphism alleles were associated with prolonged survival. One nonsynonymous allele (T112) was associated with an additional 687 days of survival for scrapie-exposed sheep compared to M112 sheep (odds ratio, 42.5; P = 0.00014). The only two sheep homozygous for T112 (TARQ) did not develop scrapie, suggesting that the allelic effect may be additive. These results provide evidence that TARQ sheep are genetically resistant to development of classical scrapie.