Virus-specific sequences in nuclear DNA from non-producer hamster Rous sarcoma

Proviral DNA from non-producer Rous sarcoma in Syrian hamster contains practically all the nucleotide sequences presented in 125I-labeled RNA from Rous sarcoma virus, Carr-Zilber strain. Virus-specific sequences consist of moderately reiterated and unique DNA regions. The amount of Rous sarcoma virus-specific provirus equivalents in hamster Rous sarcoma DNA is equal to 5.2 +/- 0.01. Experiments on transfection show that proviral DNA studied possesses biological activity in respect to cell transformation and virus production. The infectivity of DNA from hamster tumor does not depend on the expression of group-specific (gs) antigen in the recipient cells.