丝裂原活化蛋白激酶(MAPK)参与调节斑马鱼卵母细胞第一次减数分裂的恢复

旨在阐明MAPK的激活在斑马鱼(Danio rerio)卵母细胞第一次减数分裂恢复中的作用。用17α,20β双羟孕酮(17α,20β-DHP)单独作用及17α,20β-DHP与U0126(MAPK上游信号MEK阻断剂)共同作用两种方法,分别培养斑马鱼卵母细胞。采集不同培养时间的卵母细胞,经裂解变性后利用SDS-PAGE电泳和Western Blot蛋白质免疫印迹技术,检测MAPK磷酸化变化,并且观察生发泡破裂(GVBD)发生情况。结果表明,斑马鱼卵母细胞在17α,20β-DHP诱发下6h基本发生GVBD,MAPK活性在2h明显升高,一直到6h都保持在较高水平。而加入U0126后,斑马鱼卵母细胞MAPK活性受到明显抑制,同一时间GVBD发生率均低于对照组斑马鱼卵母细胞。以上结果表明,MAPK参与调节斑马鱼卵母细胞第一次减数分裂的恢复,是斑马鱼卵母细胞GVBD正常发生所必需的。

Mitogen-Activated Protein Kinase Participates in the Reinitiation of the First Meiosis in Danio rerio Oocytes

The purpose of this study is to clarify the function of mitogen-activated protein kinase (MAPK) activity in the reinitiation of the first meiosis in Zebra Fish (Danio rerio) oocytes. The oocyte maturation of D. rerio was induced in vitro by 17α, 20β-dihydroxy-4-pregnen-3-one ( 17α,2β-DHP). Another group of oocytes were treated by 17α, 20β-DHP with U0126, the inhibitor of MAPK phosphorylation. MAPK phosphorylation in oocytes obtained at different culture time points was analyzed with Western Blot, and germinal vesicle breakdown (GVBD) of oocytes was observed. The results showed that MAPK activity in oocytes in response to the 17α, 20β-DHP induction (without U01266) was significantly increased at 2 h of culture and was maintained at a high level until 6 h, and GVBD also almost completed at 6 h. In contrast, U0126 completely blocked MAPK phosphorylation in oocytes exposed to 17α,20β-DHP. GVBD rate of oocytes cultured with both of 17α,20β-DHP and U0126 was lower than that of oocytes cultured with only 17α,20β-DHP. The results suggest that MAPK participates in the resumption of the first meiosis in D. rerio oocytes.