Figure 1.

Clonal Analysis of Neocortical Excitatory Neuron Genesis and Organization Using MADM

(A) Serial sectioning and 3D reconstruction of a MADM-labeled P21 brain treated with TM at E10. Colored lines indicate the contours of the brain and colored dots represent the cell bodies of labeled neurons. The x/y/z axes indicate the spatial orientation of the clone with the y axis parallel to the brain midline and pointing dorsally. Similar display is used in subsequent 3D reconstruction images. Hip, hippocampus; Ncx, neocortex.

(B) Confocal images of the green/red G₂-X clone. Consecutive brain sections were stained with the antibodies against EGFP (green) and tdTomato (red) and with DAPI (blue). Layers are shown to the left. Arrow indicates an excitatory pyramidal neuron with a prominent apical dendrite, and open arrowhead indicates an excitatory stellate neuron. Arrowheads indicate glial cells. High-magnification images of their dendrites with numerous spines are shown in insets. Scale bars, 200 μm and 10 μm.

(C) High-magnification 3D reconstruction image of the green/red G₂-X clone. Colored lines indicate the layer boundary. WM, white matter.

(D) NND analysis of MADM-labeled neurons in the P21-30 neocortex treated with TM at E10. Data are presented as mean ± SEM.

(E) Quantification of MADM clone size (P7–P10: E10, n = 24; E11, n = 69; E12, n = 48; E13, n = 28; P21–P30: E10, n = 22; E11, n = 38; E12, n = 47; E13, n = 25).

Data are presented as mean ± SEM. (^∗p < 0.05, ^∗∗∗p < 0.001, and ^∗∗∗∗p < 0.0001). See also Figures S1 and S2 and Movies S1 and S2.