[Molecular nature of the mutations in gene ADE2 in Saccharomyces cerevisiae yeasts. III. Determination of the correlation of the GC AT pairs in genes ADE1 and ADE2].

Lethal and mutagenic effects and the nature of mutations induced by decay of 32P incorporated into yeast cell DNA as 32P-deoxyguanosine monophosphate (32PdGMP) and 32P-thymidine monophosphate (32P-TMP), were studied. The lethal efficiency per 32P decay is independent of a labelled nucleotide incorporated into DNA. However, the mutagenic efficiency in ADE1, ADE2 genes per 32P decay is approximately 3 times greater for 32PdGMP than for 32P-TMP. This suggests that ADE1, ADE2 genes contain about 3 times more GC base pairs than AT pairs. Variations in a relative frequencies of GC leads to AT and AT leads to GC transitions were obtained depending upon a nucleotide labelled.