Figure 7.

Conserved Function of Robo/Dll1 in Snake and Human Cortex to Regulate the Balance between Direct Neurogenesis and Basal Progenitor Formation

(A) Simplified phylogenic tree of amniotes with approximate reference to relative brain size and layout.

(B and C) Dorsal cortex of snake embryo at 6 dpo with neurons in the VZ (arrowheads) and apical but not basal mitoses (red).

(D and E) ISH against snake Robo2 and Dll1 in snake dorsal cortex (DC) at 6 dpo. These panels are tiled images.

(F–H) Experimental design for in ovo genetic manipulation of snake DC, representative examples and quantifications (n = 3–4 embryos per group; t tests). White arrowheads indicate basal mitoses, green arrowheads indicate GFP+ cells, typically sparse. Details in (G’) are examples of basal mitoses in GFP− cells. Right plot in (H) shows the location of PH3+ nuclei (circles) relative to the apical-basal extent of the VZ.

(I–K) Experimental design for genetic manipulation of human cerebral organoids, examples, and quantifications (n = 3–4 organoids per group; t tests). Arrowheads indicate NeuN+ neurons in the VZ. Red shadowing in (H) and (K) indicates values within group corresponding to GFP- cells.

Values are mean + SEM; ^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001; ns, not significant. MZ, mantle zone. Scale bars: 150 μm (B, D, and E), 75 μm (C and G), 50 μm (J).

See also Figure S6.