We have been studying the specific biochemical mechanisms involved in the replication of the autonomous parvovirus, KRV in a rat nephroma cell line. The virus contains one molecule of linear single-stranded DNA and three capsid proteins. Ongoing studies involve the mechanisms of viral DNA replication, the intermediates in this replication, and the proteins associated with and possibly influencing DNA replication. We are also studying the viral-specific mRNAs and their transcription. BIBLIOGRAPHIC REFERENCES: Salzman, L. A.: Evidence for terminal S1-nuclease resistant regions on single-stranded linear DNA. Virology 76: 454-458, 1977. Salzman, L. A. and F. Koczot. Isolation of nucleoprotein from the parvovirus, KRV. Virology 1977 (in press).