Macromolecular Synthesis in Newly Transformed Cells of Bacillus subtilis

Abstract

The capacity of newly transformed cells of Bacillus subtilis to synthesize deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein has been determined by following the kinetics of suicide after their exposure to tritiated precursors of each of these macromolecules. Competent cells, whether transformed or not, are heterogeneous with respect to DNA synthesis. About 40 to 50% are latent in DNA synthesis. This latency may persist for 2.5 to 3 hr since transformants are resistant to thymineless death for this period after DNA addition. The remainder of the transformants synthesize DNA at one-half the rate of the cells of the total population. Synthesis of stable RNA does not occur at an appreciable rate in newly transformed cells. Newly transformed cells, however, do synthesize protein extensively, as demonstrated by the lethality of incorporated tritiated amino acids. Either chloramphenicol or actinomycin D treatment during the time of exposure to the tritiated amino acid prevented the suicide of transformants.