Cytosine to Thymine Transitions from Decay of Cytosine-5- 3 H in Bacteriophage S13

Decay of cytosine-5-(3)H incorporated into bacteriophage S13 DNA causes a molectular rearrangement of the cytosine molecutle undergoing the decay. The molecular rearrangement produces a cytosine to thyimine coding change with at efficiency approaching one. Decay of either thymidine-(methyl)-(3)H or cytosine-6-(3)H is less than 1 percent as effective in calusing either cytosine to thymine or thymine to cytosine transitions.