DNA BIOSYNTHESIS IN MITOCHONDRIA - DIFFERENTIAL INHIBITION OF MITOCHONDRIAL AND NUCLEAR DNA POLYMERASES BY MUTAGENIC DYES ETHIDIUM BROMIDE AND ACRIFLAVIN

The DNA-intercalating dyes ethidium bromide and acriflavin strongly inhibit the enzymatic synthesis of DNA catalyzed by rat liver mitochondrial DNA polymerase. When compared with the nuclear polymerase, the mitochondrial enzyme is much more sensitive to these dyes. These observations are in accord with the well known effects of these dyes in producing cytoplasmic (mitochondrial) but not nuclear mutations in yeast and trypanosomes. A possible mechanism for the mutagenic effect of the dyes is discussed. © 1969.