Roles of microtubules and microfilaments in spindle movements during rat oocyte meiosis.
Spindle movements, including spindle migration from the center to the cortex of oocytes during first meiosis and spindle rotation during second meiosis, are required for asymmetric meiotic divisions in many species. However, little is currently known in relation to the rat oocyte. To explore how spindles move and the mechanism controlling spindle movements in rat oocytes, we observed the spindle dynamics during the two meiotic divisions in the rat oocyte by confocal microscopy. Drugs that depolymerize microtubules or microfilaments were employed to further determine the roles of these two cytoskeletons in spindle movements. The results showed that peripheral spindle migration took place during first meiosis and spindle rotation took place during second meiosis in the rat oocytes. Microfilament inhibitor inhibited both spindle migration and spindle rotation, and depolymerization of microtubules inhibited spindle rotation. Severe depolymerization of microtubules inhibited spindle migration, while migration was achieved by partial but not complete depolymerization of microtubules. We thus conclude that microfilaments are important for both spindle migration and spindle rotation and that spindle microtubules are essential for spindle movements in rat oocytes.
Ai
Jun-Shu
JS
State Key Laboratory of Reproductive Biology, Institute of Zoology, China.
Wang
Qiang
Q
Li
Mo
M
Shi
Li-Hong
LH
Ola
Safiriyu Idowu
SI
Xiong
Bo
B
Yin
Shen
S
Chen
Da-Yuan
DY
Sun
Qing-Yuan
QY
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D003571:Cytochalasin B / Q000494:pharmacology; D005260:Female; D008540:Meiosis / Q000187:drug effects / Q000502:physiology*; D008870:Microtubules / Q000187:drug effects / Q000502:physiology*; D009068:Movement / Q000502:physiology; D015739:Nocodazole / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012399:Rotation; D008941:Spindle Apparatus / Q000187:drug effects / Q000502:physiology*; D050257:Tubulin Modulators / Q000494:pharmacology
D050257:Tubulin Modulators; D003571:Cytochalasin B; D015739:Nocodazole