Abstract
In order to understand the mechanism of unequal division, polar body formation was investigated using the oocytes of the starfish, Asterina pectinifera. Cortical actin filaments were quantitatively measured after staining the maturing oocytes with fluorescently labeled phalloidin using a computer and image-processing software. Before polar body formation, at first the actin filaments at the animal pole decreased and subsequently the animal pole bulged. On the other hand, actin filaments surrounding the animal pole increased gradually and made a cleavage furrow around the animal pole as the bulge grew. Then the furrow ingressed and finally a polar body formed. When the surface force was calculated according to the cell shape, the surface force decreased at the animal pole but the force at the contractile ring increased. When by micromanipulation the mitotic apparatus was detached and translocated to the cortex other than the animal pole, polar body formation occurred all over the cortex of the oocyte, which indicates that the response of the whole cortex to the mitotic apparatus is equal. These results indicate that the decrease in the actin filaments and surface force near the centrosome of the mitotic apparatus as well as the increase in the actin filaments and surface force at some distance of the centrosome is important for cytokinesis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
