THE SYNTHESIS OF DNA, RNA, AND NUCLEAR PROTEIN IN NORMAL AND TUMOR STRAIN CELLS

Abstract

Interferometric and and photometric measurements have been made on replicating mouse ascites tumor cell cultures. From a study of the relations between successive physical measurements on individual cells, it was found that whereas the net syntheses of nuclear RNA (ribonucleic acid) and nuclear protein are closely associated during interphase, they are dissociated from DNA (deoxyribonucleic acid) replication to a significant extent. These results agree with others reported in replicating cell strains derived from tumors. In auxilliary experiments an attempt was made to block the initiation of DNA synthesis by X-irradiation: although large amounts of nuclear protein accumulated in some cells in the absence of DNA synthesis, the inability to hold the DNA block for an interphase time prevented a quantitative analysis of the results.