RT Journal Article SR Electronic(1) A1 Lacroux, C. A1 Corbière, F. A1 Tabouret, G. A1 Lugan, S. A1 Costes, P. A1 Mathey, J. A1 Delmas, J. M. A1 Weisbecker, J. L. A1 Foucras, G. A1 Cassard, H. A1 Elsen, J. M. A1 Schelcher, F. A1 Andréoletti, O.YR 2007 T1 Dynamics and genetics of PrPSc placental accumulation in sheep JF Journal of General Virology, VO 88 IS 3 SP 1056 OP 1061 DO https://doi.org/10.1099/vir.0.82218-0 PB Microbiology Society, SN 1465-2099, AB Placentae from scrapie-affected ewes are an important source of contamination. This study confirmed that scrapie-incubating ewes bearing susceptible genotypes could produce both abnormal prion protein (PrPSc)-positive and -negative placentae, depending only on the PRP genotype of the fetus. The results also provided evidence indicating that scrapie-incubating ARR/VRQ ewes may be unable to accumulate prions in the placenta, whatever the genotype of their progeny. Multinucleated trophoblast cells appeared to play a key role in placental PrPSc accumulation. PrPSc accumulation began in syncytiotrophoblasts before disseminating to uninucleated trophoblasts. As these result from trophoblast/uterine epithelial cell fusion, syncytiotrophoblast cells expressed maternal and fetal PrPC, whilst uninucleated trophoblast cells only expressed fetal PrPC. In ARR/VRQ scrapie-infected ewes, expression of the ARR allele by syncytiotrophoblasts appeared to prevent initiation of PrPSc placental deposition. The absence of prions in affected ARR/VRQ sheep placentae reinforces strongly the interest in ARR selection for scrapie control., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.82218-0