The Effects of Some Inhibitors of RNA Synthesis and Proteolysis on Morphogenesis in Acetabularia mediterranea )

Abstract

Summary The effects of a number of inhibitors of RNA synthesis and proteolysis on morphogenesis in Acetabularia have been studied. While camptothecin had no effect, cordycepin acted like actinomycin D: it did not inhibit cap formation in anucleate halves, but stopped growth in nucleate ones. Two inhibitors of trypsin-like protease, TLCK and TAME, arrested morphogenesis and growth in both kinds of fragments; inhibition was reversible in nucleate halves; in anucleate halves, it was irreversible after TLCK, partially reversible after TAME treatment. No binding sites for Con A coud be detected with fluorescent lectin. Two organomercurials (PCMB, PCMBS) inhibited strongly growth and morphogenesis in both kinds of fragment; reversibility is much better in nucleate halves than in anucleate ones. The significance of these results is discussed.