Localization of gamma-tubulin in mouse eggs during meiotic maturation, fertilization, and early embryonic development.
Gamma-tubulin, a member of the tubulin superfamily, is a peri-centriolar component which is considered to be essential for microtubule nucleation. The dynamics of gamma-tubulin during mouse oocyte meiotic maturation, fertilization, and early cleavage as well as the co-localization of gamma-tubulin and alpha-tubulin during the formation of the meiotic I spindle were studied by confocal microscopy. We found that gamma-tubulin was evenly distributed in the germinal vesicle (GV) stage oocyte. After germinal vesicle breakdown (GVBD) gamma-tubulin dots were localized in both the cytoplasm and the vicinity of the condensed chromosomes, and aligned at both poles of the meiotic spindle at prometaphase I and metaphase I. At anaphase I and telophase I, gamma-tubulin was detected between the separating chromosomes, while it was absent in the midbody. At the MII stage, gamma-tubulin was again accumulated at the spindle poles. Alpha-tubulin had a similar distribution pattern as gamma-tubulin in the cytoplasm and radiated from gamma-tubulin foci close to the chromosomes during the meiotic spindle formation. After fertilization, gamma-tubulin was translocated from spindle poles to the area between separating chromatids and distributed around the pronuclei. It aggregated into some dots during the interphase, but was distributed on the mitotic spindle poles in early embryos. Our results suggest that gamma-tubulin is essential for microtubule nucleation and spindle formation during mouse oocyte meiosis, fertilization, and early embryo cleavage.
Meng
Xiao-Qian
XQ
State Key Laboratory of Reproductive Biology, Institute of Zoology, The Chinese Academy of Sciences, Beijing 100-080, PR China.
Fan
Heng-Yu
HY
Zhong
Zhi-Sheng
ZS
Zhang
Gang
G
Li
Yun-Long
YL
Chen
Da-Yuan
DY
Sun
Qing-Yuan
QY
D000818:Animals; D002455:Cell Division / Q000502:physiology; D005314:Embryonic and Fetal Development; D005260:Female; D005306:Fertilization / Q000502:physiology*; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D018613:Microscopy, Confocal; D009865:Oocytes / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism*; D015053:Zygote / Q000378:metabolism
D014404:Tubulin