Fig. 4.

PP2Ac accumulation mediates the axon abnormality following Mid1 down-regulation. (A) Mid1 negatively regulates the protein level of PP2Ac. Cortical neurons electroporated with the constructs indicated were harvested and subjected to immunoblotting at 4 DIV. For quantification, GAPDH was used as the loading control. n = 3 in each group. *P < 0.05, Student t test. (B) Mid1 and PP2Ac interact in cultured neurons. Cortical neurons were harvested at 4 DIV, and immunoprecipitation was performed with the antibodies indicated. Mid1 and PP2Ac were detected with specific antibodies. (C) Representative images of neurons transfected with different constructs at 4 DIV. GFP was amplified by immunostaining to visualize the cell morphology. (D) Quantitative analysis of the total axonal length and number of axonal terminals. Results are shown as mean ± SEM. More than 100 neurons from four independent experiments were analyzed in each group. ***P < 0.001, Student t test. (E) Representative images of brain slices at the level of Bregma −1.58 mm from P14 animals transfected with indicated constructs. The projection patterns of callosal axons were shown by GFP staining. (F) The axon distribution index of brain slices from P14 mice in different groups. n = 6–7 in each group. ***P < 0.001, compared with Mid1 RNAi, t test. (Scale bar: C, 20 μm; E, 500 μm.)