Figure 2
From: Ascl1 is a required downstream effector of Gsx gene function in the embryonic mouse telencephalon
Expansion of Gsx1 in the Gsx2EGFP/EGFPlateral ganglionic eminence (LGE) occurs in only a subset of cells at the ventricular zone (VZ)/subventricular zone (SVZ) border. (A-C) Control embryos (Gsx2EGFP/+) express Gsx2 and enhanced green fluorescent protein (EGFP) throughout the VZ of the LGE at E16.5. In addition, the Gsx1/2 antibody labels scattered cells in the SVZ (B) where EGFP expression is observed in the majority of the SVZ (A, C). Asterisks in (A, C) mark Gsx1/2 staining in the remnant of the medial ganglionic eminence. Because EGFP expression from the Gsx2 locus is not found in this region, it is likely that the staining reflects Gsx1 expression. (G) The expansion of Gsx1 in Gsx2EGFP/EGFPembryos is throughout the LGE at E16.5. (F, H) Note that Gsx1 expression in Gsx2EGFP/EGFPembryos is observed only at the VZ/SVZ border in the LGE (arrows in merged image in (H)) whereas EGFP expression (labeling Gsx2 mutant cells) is observed throughout the VZ and the SVZ (F, H). (D, E) Control embryos (Gsx2EGFP/+) express Ascl1 at highest levels near the VZ/SVZ border (D) and only in scattered cells of the VZ (merged image with EGFP in (E)). (I) By E16.5, Ascl1 is recovered in the LGE of Gsx2EGFP/EGFPembryos predominately at the VZ/SVZ border (arrows in (J)), which is similar to the expansion of Gsx1 expression in these mutants (G).