The stalked bacterium Caulobacter bacteroides, which displays a series of developmental changes during its life cycle, was shown to contain the methylated deoxyribonucleic acid (DNA) nucleotide bases N 6-methyladenine and 5-methylcytosine as well as the enzymes required for the synthesis of these bases. A difference in the specific activity of these enzymes was observed between swarmer cells, which are low in activity, and stalked cells, which are high in activity. This difference was not

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... ted in the methylation patterns in the DNA of the two cell types since C. bacteroides DNA is essentially completely methylated with respect to C. bacteroides methylases.