Electrophoretic introduction of calcium ions into the cortex of Xenopus laevis oocytes triggers meiosis reinitiation

Abstract
Meiosis reinitiation has been triggered via electrophoretic driving of Ca++ into the cortex of Xenopus laevis oocytes freed from functional follicle cells by collagenase treatment. Mg++ could not be substituted for Ca++. Ca++ induced maturation resembles progester-one induced maturation in so far both are inhibited by cycloheximide, give rise to amplifiable MPF in the cytoplasm of treated oocytes and allow chromosome condensation and the formation of a normal meiotic spindle.