Synthesis and transmethylation of DNA in polyoma-infected cultures☆

摘要: Abstract The incorporation of label from l -methionine (methyl-H 3 ), sodium formate-C 14 , and thymidine-H into the DNA mouse kidney cultures, labeled 3rd to 36th hour after polyoma virus infection, was increased severalfold over that in uninfected control cultures. Evidence obtained by means several methods showed this synthesis involved cellular addition viral DNA. On basis methyl group methionine 5-methylcytosine both infected it concluded these cultures accompanied direct transmethylation. amount transmethylation proportional synthesized. There no evidence induces hypermethylation experiments on with ) also provided extracted contains 5-methylcytosine. It calculated approximately one-tenth normally present mammalian cell