Effect of Acriflavine and Ethidium Bromide on the Synthesis of RNA of the Peripheral Nerve in the Chick during Development

The effect of the trypanocidal dyes acriflavine and ethidium bromide on the sedimentation pattern of tritium-labelled RNA of the sciatic nerve of chicks was studied. Tissues from 14-day embryos, 17-day embryos, and 3-day chicks were incubated with [5-3H]uridine in organ culture, in the presence and in the absence of the inhibitors. Acriflavine and especially ethidium bromide caused a selective inhibition of the labelling of the RNA species which sedimented between the 17.2 S and 5.8 S components of the bulk RNA in the older animals. The labelling of the RNA with sedimentation values higher than 17.2 S was not decreased by ethidium bromide during a 1.5 h incubation period, indicating that rRNA, rRNA precursors, or heterogeneous nuclear RNA was not affected by the drug.