Membrane response to 1-methyladenine requires the presence of the nucleus

Abstract
Meiosis is re-initiated in starfish oocytes by the action of the hormone 1-methyladenine (1-MA)1. It is thought that the primary trigger is localised at the plasma membrane2,3, and early changes reported are the activation of a Na+ pump4 and variation in membrane potential and conductance5,6. We report here that external application of 1-MA results in an irreversible switching of the starfish oocyte membrane from one stable electrical state to another. This induced change requires the presence of the germinal vesicle.