Aurora-A is a critical regulator of microtubule assembly and nuclear activity in mouse oocytes, fertilized eggs, and early embryos.
Aurora-A is a serine/threonine protein kinase that plays a role in cell-cycle regulation. The activity of this kinase has been shown to be required for regulating multiple stages of mitotic progression in somatic cells. In this study, the changes in aurora-;A expression were revealed in mouse oocytes using Western blotting. The subcellular localization of aurora-A during oocyte meiotic maturation, fertilization, and early cleavages as well as after antibody microinjection or microtubule assembly perturbance was studied with confocal microscopy. The quantity of aurora-A protein was high in the germinal vesicle (GV) and metaphase II (MII) oocytes and remained stable during other meiotic maturation stages. Aurora-A concentrated in the GV before meiosis resumption, in the pronuclei of fertilized eggs, and in the nuclei of early embryo blastomeres. Aurora-A was localized to the spindle poles of the meiotic spindle from the metaphase I (MI) stage to metaphase II stage. During early embryo development, aurora-A was found in association with the mitotic spindle poles. Aurora-A was not found in the spindle region when colchicine or staurosporine was used to inhibit microtubule organization, while it accumulated as several dots in the cytoplasm after taxol treatment. Aurora-A antibody microinjection decreased the rate of germinal vesicle breakdown (GVBD) and distorted MI spindle organization. Our results indicate that aurora-A is a critical regulator of cell-cycle progression and microtubule organization during mouse oocyte meiotic maturation, fertilization, and early embryo cleavage.
Yao
Li-Juan
LJ
State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 10080, People's Republic of China.
Zhong
Zhi-Sheng
ZS
Zhang
Li-Sheng
LS
Chen
Da-Yuan
DY
Schatten
Heide
H
Sun
Qing-Yuan
QY
D000818:Animals; D000906:Antibodies / Q000008:administration & dosage / Q000494:pharmacology; D064096:Aurora Kinase A; D064127:Aurora Kinases; D002467:Cell Nucleus / Q000502:physiology*; D016922:Cellular Senescence; D004622:Embryo, Mammalian / Q000502:physiology*; D047108:Embryonic Development; D005306:Fertilization / Q000502:physiology; D051379:Mice; D008815:Mice, Inbred Strains; D008845:Microinjections; D008870:Microtubules / Q000502:physiology*; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D008941:Spindle Apparatus / Q000187:drug effects / Q000502:physiology; D013347:Subcellular Fractions / Q000378:metabolism; D015053:Zygote / Q000502:physiology*
D000906:Antibodies; C576918:Aurka protein, mouse; D064096:Aurora Kinase A; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases