NR ALUR
AU Tuo,W.; O'Rourke,K.I.; Zhuang,D.; Cheevers,W.P.; Spraker,T.R.; Knowles,D.P.
TI Pregnancy status and fetal prion genetics determine PrPsc accumulation in placentomes of scrapie-infected sheep
QU Proceedings of the National Academy of Sciences of the United States of America 2002 Apr 30; 99(9): 6310-5
PT journal article
AB Ovine scrapie is a fatal neurodegenerative disorder that may be transmitted through exposure to infected uterine and placental tissues. Susceptibility to scrapie is primarily controlled by polymorphisms in the prion protein (PrP) gene. Scrapie in the U.S. Suffolk breed and in many breeds in Europe occurs in sheep homozygous for glutamine (171QQ), but rarely in sheep heterozygous for glutamine and arginine (171QR) or homozygous for arginine (171RR) at codon 171 of the PrP gene. This study demonstrated that accumulation of PrPsc in uterine-placental epithelial cells in the placentome was determined by fetal PrP genotype and the pregnancy status of scrapie-infected ewes. PrPsc was detected in 171QQ placentomes of infected ewes, but not in placentomes of infected ewes pregnant with 171QR conceptuses or in the non-pregnant uterus of infected ewes. The distribution of PrPsc plaques in placentomes was temporally associated with stage of gestation. There was a tendency toward increased size and number of placentomal PrPsc plaques from the endometrial stalk (maternal side) to chorionic plate (fetal side). These results indicate that accumulation of PrPsc is eliminated or reduced to undetectable levels in reproductive and placental tissues if infected ewes are not pregnant or conceive conceptuses with a resistant PrP genotype.
IN
Die Autoren meinen, Scrapie komme in amerikanischen und vielen europäischen Suffolk-Schafherden hauptsächlich in Schafen vor, die im Codon 171 des Prionproteingens ein Glutamin codieren. Codieren die Schafe in diesem Codon homozygot Arginin oder heterozygot Glutamin auf den einen und Arginin auf dem anderen Chromosom, dann scheinen die Suffolk-Schafe zumindest gegenüber den in den USA üblichen Scrapie-Erregerstämmen weitgehend immun zu sein.
Die Autoren berichten, dass epitheliale Zellen im Uterus Scrapie-infizierter Schafe nur da PrPsc akkumulieren, wo sich eine Plazenta für einen Fötus gebildet hat, der hinsichtlich des Codons 171 des Prionproteingens homozygot Glutamin codiert.
MH Animal; Blotting, Western; Endometrium/metabolism; Female; Genotype; Heterozygote; Homozygote; Immunohistochemistry; Placenta/*metabolism; PrPsc Proteins/*biosynthesis/*genetics; Pregnancy; Pregnancy, Animal; Scrapie/*metabolism; Sheep; Support, U.S. Gov't, Non-P.H.S.; Time Factors
AD Animal Disease Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA 99164, USA. wtuo@vetmed.wsu.edu
SP englisch
PO USA