Translator Disclaimer
1 March 2003 Rotation of Meiotic Spindle Is Controlled by Microfilaments in Mouse Oocytes
Author Affiliations +

The completion of meiosis requires the spatial and temporal coordination of cytokinesis and karyokinesis. During meiotic maturation, many events, such as formation, location, and rotation of the meiotic spindle as well as chromosomal movement, polar body extrusion, and pronuclear migration, are dependent on regulation of the cytoskeleton system. To study functions of microfilaments in meiosis, we induced metaphase II (MII) mouse oocytes to resume meiosis by in vitro fertilization or parthenogenetic activation, and we treated such oocytes with cytochalasin B (CB). The changes of the meiotic spindle, as visualized in preparations stained for β-tubulin and chromatin, were observed by fluorescent confocal microscopy. The meiotic spindle of MII oocytes was observed to be parallel to the plasmalemma. After meiosis had resumed, the spindle rotated to the vertical position so that the second polar body could be extruded into the perivitelline space. When meiosis resumed and oocytes were treated with 10 μg/ml of CB, the spindle rotation was inhibited. Consequently, the oocyte formed an extra pronucleus instead of extruding a second polar body. These results indicate that spindle rotation is essential for polar body extrusion; it is the microfilaments that play a crucial role in regulating rotation of the meiotic spindle.

Zi-Yu Zhu, Da-Yuan Chen, Jin-Song Li, Li Lian, Lei Lei, Zhi-Ming Han, and Qing-Yuan Sun "Rotation of Meiotic Spindle Is Controlled by Microfilaments in Mouse Oocytes," Biology of Reproduction 68(3), 943-946, (1 March 2003).
Received: 1 August 2002; Accepted: 1 September 2002; Published: 1 March 2003

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top