@article {536,
	title = {Prevention of scrapie transmission in sheep, using embryo transfer},
	journal = {Am J Vet Res},
	volume = {54},
	year = {1993},
	note = {Foote, W C Clark, W Maciulis, A Call, J W Hourrigan, J Evans, R C Marshall, M R},
	month = {Nov},
	pages = {1863 - 8},
	edition = {34274},
	abstract = {Reciprocal embryo transfers were made between scrapie-inoculated and scrapie-free sheep (Cheviot and Suffolk breeds) to measure scrapie transmission via the embryo (using offspring from embryos of scrapie-inoculated donors and scrapie-free recipients) and via the uterus (using offspring from embryos of scrapie-free donors and scrapie-inoculated recipients taken by cesarean section). Two control groups of offspring, 1 from scrapie-free parents (negative) and 1 from scrapie-inoculated parents (positive), also were included. All sheep were observed for clinical signs of scrapie until death or for a minimum of 60 months. Final diagnosis was made on the basis of histopathologic findings or results of mouse inoculation and/or proteinase-K-resistant protein analysis. Thirty to 61\% of the scrapie-inoculated donor/recipient sheep within groups developed scrapie within 8 to 44 months after inoculation. None of the scrapie-free donor/recipients, including those gestating embryos from scrapie-inoculated donors, developed scrapie. Also, none of the offspring observed to > or = 24 months of age from reciprocal cross, via embryo (0/67), or via the uterus (0/25), or from the negative-control group (0/33) developed scrapie. Fifty-six of the offspring via embryo, 19 of these via the uterus, and 31 negative controls survived to > or = 60 months of age. Of the 21 sheep in the positive-control group, 2 (9.5\%) developed scrapie, 1 at 31 months of age and 1 at 42 months of age. In the Cheviot offspring, the percentage of sheep carrying the short incubation allele ranged from 24 to 44\% and the percentage in the Suffolk offspring ranged from 61 to 83\%.(ABSTRACT TRUNCATED AT 250 WORDS)},
	keywords = {Animals, Embryo Transfer, Embryo, Mammalian / microbiology, Female, Maternal-Fetal Exchange, Pregnancy, Prions / isolation \& purification, Scrapie / microbiology / *prevention \& control / *transmission, Sheep, Time Factors, Uterus / microbiology},
	issn = {0002-9645 (Print) 0002-9645 (Linking)},
	author = {Foote,W. C. and Clark,W. and Maciulis,A. and Call,J. W. and Hourrigan,J. and Evans,R. C. and Marshall,M. R. and de Camp,M.}
}
