The distribution and possible role of ERK8 in mouse oocyte meiotic maturation and early embryo cleavage.
It is well known that extracellular signal-regulated kinase 8 (ERK8) plays pivotal roles in various mitotic events. But its physiological roles in oocyte meiotic maturation remain unclear. In this study, we found that although no specific ERK8 signal was detected in oocyte at the germinal vesicle stage, ERK8 began to migrate to the periphery of chromosomes shortly after germinal vesicle breakdown. At prometaphase I, metaphase I (MI), anaphase I, telophase I, and metaphase II (MII) stages, ERK8 was stably detected at the spindles. By taxol treatment, we clarified that the ERK8 signal was stained on the spindle fibers as well as microtubule asters in MI and MII oocytes. In fertilized eggs, the ERK8 signal was not observed in the two pronuclei stages. At prometaphase, metaphase, and anaphase of the first mitosis, ERK8 was detected on the mitotic spindle. ERK8 knock down by antibody microinjection and specific siRNA caused abnormal spindles, failed chromosome congression, and decreased first polar body extrusion. Taken together, our results suggest that ERK8 plays an important role in spindle organization during mouse oocyte meiotic maturation and early embryo cleavage.
Center for Reproductive Medicine, Department of Ob/Gy, Nanfang Hospital, Southern Medical University, Guangzhou City, Guangdong Province, China.
Shang-Wu
SW
Yang
Hao
H
Huang
Chen
C
Gao
Lei
L
Chen
Shu-Tao
ST
Qi
Fei
F
Lin
Jian-Xin
JX
Wang
Yi
Y
Hou
Fu-Qi
FQ
Xing
Qing-Yuan
QY
Sun
D000818:Animals; D004622:Embryo, Mammalian / Q000166:cytology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D008540:Meiosis; D051379:Mice; D009865:Oocytes / Q000254:growth & development*; D008941:Spindle Apparatus / Q000737:chemistry / Q000378:metabolism*
D048049:Extracellular Signal-Regulated MAP Kinases