A test of EcoRI and HindIII restriction fragment length polymorphisms in assessing susceptibility for scrapie in US Suffolk sheep

Ž . We investigated the distribution of EcoRI restriction fragment length polymorphism RFLP and tested EcoRI and HindIII RFLPs to ascertain the occurrence of scrapie in Suffolk sheep. Genomic DNA samples were collected from 527 Ž . animals and typed for EcoRI RFLP by Southern blot analysis using the PrP gene clone probe pNPU42 . The average e1 frequency in Suffolk sheep was 64.4% and ranged from 51.5 to 82.2%, which was significantly higher than the average in Ž . Ž . Cheviot 32.3% and Rambouillet sheep 17.7% . The association of histopathologic diagnosis with RFLPs was investigated using 82 animals exposed orally with scrapie inoculum in a double-blind, retrospective experimental design. There was a Ž . significant P-0.01 association between EcoRI RFLP and scrapie histopathologic diagnosis in Suffolk sheep with the e1e1 genotype. The use of the EcoRI RFLP phenotype for scrapie-diagnosis, however, was inconsistent for some individual cases. HindIII-produced RFLPs was not significantly related to scrapie diagnosis. q 1998 Elsevier Science B.V.