REPLICATION PROPERTIES OF DUTPASE-DEFICIENT MUTANTS OF CAPRINE AND OVINE LENTIVIRUSES

The virion-associated dUTPase activities of caprine arthritis-encephal itis virus (CAEV) and visna virus were determined by using an assay wh ich measures the actual ability of the dUTPase to prevent the dUTP mis incorporations into cDNA during reverse transcription. We showed that the CAEV molecular clone from the Cork isolate was dUTPase defective a s a result of a single amino acid substitution. Using this point mutan t and deletion mutants of CAEV as well as a deletion mutant of visna v irus, we demonstrated that dUTPase-deficient viruses replicate similar ly to wild-type viruses in dividing cells but show delayed replication in nondividing primary macrophages.