OBJECTIVES: (1) The biological function and enzymatic properties of AMV p32 DNA-endonculease. (2) The precursor product relationship between RNase H species associated with murine retroviruses. (3) Identify, isolate, and characterize a reverse transcription complex in the cytoplasm of mouse embryo cells. (4) Perform a detailed analysis of the viral coded and virus-induced cell coded proteins synthesized during synchronous transformation of cells by mammalian sarcoma viruses. (5) Analysis of the integration pattern of Moloney "sarc" in normal and transformed murine cells.