Figure 3. GSK-3 signaling is dispensable for tangential migration, but required for radial hippocampal migration.
(A–A') E19.5 coronal sections showing EYFP-expressing interneurons in heterozygous control and Gsk3:Dlx5/6 mutants crossed with the Ai3 reporter line. Gsk3-deleted interneurons (green) enter the cortex in two streams in both controls and mutants (arrowheads). Mutants showed no overt migration defect. Nuclei were counterstained with Hoechst. (n = 3). (B–B') E19 coronal sections of control and Gsk3:Neurod6 mutants showing CTIP2 (green) expressing neurons in the hippocampus. In the Gsk3:Neurod6 mutants, the pyramidal cell layer (green) does not extend laterally into a compact CA1 region and remains dispersed (yellow arrowheads). Fimbrial axonal projections appear normal in Gsk3:Neurod6 mutants (orange arrow). Nuclei were counterstained with DRAQ5. Scale bar = 500 μm. (n = 3). (C–C') Higher magnification of hippocampal area shown in (B). The Gsk3:Neurod6 mutants show disrupted cytoarchitecture. In the mutants, DRAQ5-labeled cells are mislocalized and diffuse (arrowheads) and fail to form clearly defined CA1/CA3 regions of the hippocampus. The Gsk3:Neurod6 mutant mice also lack a clearly defined hippocampal sulcus (green bars) and dentate gyrus (DG). (D) Representative Western blot of E18 MGE lysates confirm strongly reduced GSK-3β protein after recombination with Dlx5/6-Cre. (E) Quantification of protein knockdown in D (n = 3 WT, n = 3 CKO, unpaired t-test).
Figure 3—figure supplement 1. No apparent migration defect in Gsk3:Dlx5/6 mice.
