In vitro synthesis of infectious transforming DNA by the avian sarcoma virus reverse transcriptase

Infectious DNA molecules, capable of transforming chicken embryo fibroblasts, can be synthesized by the Rous sarcoma virus-associated reverse transcriptase in vitro. The optimal enzymatic conditions employed for infectious DNA synthesis also facilitate maximum synthesis of genome length DNA. Analysis of the DNA product synthesized by detergent-disrupted Rous sarcoma virus under these conditions indicates that DNA complementary to viral RNA (minus-strand DNA) is genome length in size, whereas DNA complementary to genome length minus-strand DNA (plus-strand DNA) appears as subgenomic-length molecules ranging between 300 and 3,500 nucleotides in length. These features of the DNA product synthesized by the Rous sarcoma virus reverse transcriptase in vitro are similar to those identified in the cytoplasm of cells shortly after infection and lend credence to studies of the mechanism of reverse transcription in vitro and their significance to proviral DNA synthesis in vivo.