Figure 1. Overexpression of Ascl1 and Dlx2 in the ventral telencephalon promotes tangential migration.

Four days after electroporation, brains of E19.5 rats were dissected and sectioned in the coronal plane. Electroporated cells were labeled with anti-GFP in green; nuclear DNA was stained with DAPI in blue. Red dashed lines indicate the electroporation region in (A–G). (A) A confocal image of brain section; red dashed lines mark the electroporated region and a red square indicate the area for (B–D). ST: striatum, LV: lateral ventricle. (B–D) GFP-positive cells were distributed in the ST adjacent to the LV. (E) In the control group, some GFP-positive cells were distributed in the VZ/SVZ (white arrows) of the dorsal telencephalon, while most remained in the ventral telencephalon. (F) In Ascl1 group, GFP-positive cells were distributed in both the VZ/SVZ (white arrows) and IZ (white arrowheads) of the dorsal telencephalon. (G) In Dlx2 group, many GFP-positive cells were distributed in the VZ/SVZ (white arrow). Red squares indicate the zoom-in areas for 1E’ to G’. Length of the scale bar is 40 μm in (B–D) and (E’–G’), 250 μm in (E–G). (H) Quantification of GFP-positive cell density in the dorsal telencephalon. (I) Quantification of GFP-positive cells in the VZ/SVZ, IZ, or non-tangentially migrating cells in the dorsal telencephalon. Data were presented as mean ± standard error of the mean (SEM) with all data points and analyzed by Student’s t-test, n = 3. *p < 0.05; **p < 0.01 compared to the control group.