title: Transmissibility of caprine scrapie in ovine transgenic mice.
abstract: BACKGROUND
  The United States control program for classical ovine scrapie is based in part on the finding that infection is typically spread through exposure to shed placentas from infected ewes. Transmission from goats to sheep is less well described. A suitable rodent model for examining the effect of caprine scrapie isolates in the ovine host will be useful in the ovine scrapie eradication effort. In this study, we describe the incubation time, brain lesion profile, glycoform pattern and PrPSc distribution patterns in a well characterized transgenic mouse line (Tg338) expressing the ovine VRQ prion allele, following inoculation with brain from scrapie infected goats.
  
  
  RESULTS
  First passage incubation times of caprine tissue in Tg338 ovinized mice varied widely but second passage intervals were shorter and consistent. Vacuolation profiles, glycoform patterns and paraffin-embedded tissue blots from terminally ill second passage mice derived from sheep or goat inocula were similar. Proteinase K digestion products of murine tissue were slightly smaller than the original ruminant inocula, a finding consistent with passage of several ovine strains in previous reports.
  
  
  CONCLUSIONS
  These findings demonstrate that Tg338 mice propagate prions of caprine origin and provide a suitable baseline for examination of samples identified in the expanded US caprine scrapie surveillance program.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Pullman, WA 99164, USA. korourke@vetmed.wsu.edu
authors.forename: Katherine I
authors.initials: KI
authors.lastname: O'Rourke
authors.forename: David A
authors.initials: DA
authors.lastname: Schneider
authors.forename: Terry R
authors.initials: TR
authors.lastname: Spraker
authors.forename: Rohana P
authors.initials: RP
authors.lastname: Dassanayake
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Highland
authors.forename: Dongyue
authors.initials: D
authors.lastname: Zhuang
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Truscott
mesh_terms: D000818:Animals; D001681:Biological Assay; D015511:Goat Diseases / Q000235:genetics* / Q000635:transmission*; D006041:Goats; D051379:Mice; D008822:Mice, Transgenic; D018620:PrPSc Proteins / Q000145:classification* / Q000378:metabolism* / Q000472:pathogenicity; D012608:Scrapie / Q000145:classification / Q000235:genetics* / Q000635:transmission*; D012756:Sheep; D014481:United States
chemical_list: D018620:PrPSc Proteins