RNA directed DNA polymerase activity in Greene hamster melanoma

As part of a biochemical search for a virus in melanomas preliminary kinetic studies with RNA directed DNA polymerase from avian myeloblastosis virus showed that thymidine labeled triphosphate (TTP) stimulates the enzyme. This stimulatory effect was used as an additional probe in detecting RNA directed DNA polymerase activity in Greene hamster melanoma in vivo. This enzyme activity, however, was not found in the Greene hamster melanoma cells growing in tissue culture under ordinary conditions. When the cells were treated with BUDR the enzyme could be demonstrated and the stimulating effect of TTP was observed.