Inhibition of regeneration of Acetabularia mediterranea enucleated posterior stalk segments by electrical isolation

In 1959, J. and Ch. Hämmerling have shown that posterior stalk segments (EPSS) of Acetabularia mediterranea are able to regenerate in the light after enucleation, if they have been previously kept for more than 5 days in the dark in the presence of the nucleus. This experiment was repeated but with a modification which isolated electrically the apical and basal ends of the EPSS segments during their illumination. The modification consisted in separating the culture medium (artificial sea water -ASW) into compartments in such a way that the apical end of the EPSS was dipping in one compartment, while its basal end was dipping in another compartment. In this case the regeneration was inhibited. When establishing an electrical connection between the compartments by addition of an agar-ASW bridge a normal regeneration was obtained, in conformity to the Hämmerling's result. © 1975.