The dynamics and functions of cytoskeleton during meiotic resumption induced by parthenogenetic activation in mouse oocytes

The completion of meiosis requires the spatial and temporal coordination of cytokinesis and karyokinesis. Cytoskeleton system is important for regulating a series of events during meiotic maturation. M II stage mouse oocytes were induced to resume meiosis by parthenogenetic activation, and part of them were treated with cytochalasin B and nocodazole, drugs against cytoskeleton. In order to study functions of microtubules and microfilaments in meiosis, the dynamic changes of microtubules, microfilaments and chromosomes were observed by fluorescent confocal microscopy, and the following results were obtained. Meiotic spindle made up of microtubules is essential to location, separation and movement of chromosomes. The spindle rotation from parallel to vertical with respect to plasmalemma is a premise of polar body extrusion. Microfilaments play a crucial role in regulating spindle rotation. After fulfilling the rotation, microfilaments depolymerize immediately, and therefore do not participate in final extruding of polar body. After forming the pronuclei, microfilaments will assemble again, so as to control the migration of pronuclei.