The Effects of Inhibitors of Macromolecular Biosynthesis upon the Persistent Rhythm of Luminescence in Gonyaulax

Certain inhibitors of nucleic acid and protein synthesis, namely actinomycin D, mitomycin C, and puromycin, have been found to block the expression of a persistent daily rhythm of bioluminescence. The action does not inhibit luminescence per se but rather the rhythmicity. Exposure of the cells to these inhibitors for only a few hours, which might be expected to thereby delay the rhythm by a few hours, does not in fact have this effect. Chloramphenicol and amethopterin do not inhibit the rhythm. It is proposed that the functioning of the clock-like rhythmic mechanism depends upon the cell's normal ability to synthesize RNA.