Novel ribonucleic acid species in Eimeria nieschulzi are associated with RNA-dependent RNA polymerase activity.

Sporulated oocysts of Eimeria nieschulzi, E. tenella and E. acervulina were screened for the presence of putative viral nucleic acids. An RNA-dependent RNA polymerase activity in E. nieschulzi correlated with the presence of unknown nucleic acid species that were absent in the two other species of Eimeria. The novel nucleic acid species also served as templates for RNA-polymerase activity in in vitro synthesis of full-length labelled transcripts. These nucleic acid species were shown to be RNAse-sensitive and were suspected to represent the genomic RNA of a putative virus.