Fig. 7

Ectopic RAC1 expression in Net1-depleted oocytes rescued meiotic defects. (A) Western blotting analysis showed that exogenous Myc-Rac1 protein was efficiently overexpressed by blotting with anti-RAC1 antibody. Bands of endogenous and exogenous RAC1 protein are indicated. (B) Representative images of control, Net1-KD and Net1-KD + Rac1-OE oocytes. Red arrowheads denote oocytes with apparent symmetrical division and blue arrowheads indicate oocytes that fail to extrude polar bodies (scale bar, 80 μm). (C) The percentage of oocytes with large polar bodies in the control, Net1-siRNA and Net1-siRNA + Rac1 mRNA injection (7.6 ± 1.02% vs. 29.1 ± 3.05% vs. 18.7 ± 2.33%). (D) Proposed model for the role of NET1 in spindle assembly and actin dynamics in mouse oocytes. When the NET1 level was reduced in oocytes, increased HACE1 activity promoted RAC1 degradation and precipitated meiotic abnormalities in mouse oocytes