Fig. 5

Spinal cord radial glial mutants. A-O: Lateral views of the trunk, anterior left. A: Wild-type spinal cord showing axon bundles (green) and radial glia (red) observed in a full maximum intensity projection (superficial, left panel). The typical placement and number of Gfap-labeled radial glial cell bodies at the ventricular zone (arrowheads) is seen in a projection of optical slices encompassing the full ventricular zone (“VZ”, right panel). B:rrm2 mutants had axonal and astroglial phenotypes characteristic of nonspecific defects that are likely caused by ubiquitous cell death. Right half shows only the channel for αGfap labeling (red), while the left half also includes αAT labeling for axons. C-O: Mutants with altered numbers of αGfap-labeled cell bodies within the spinal cord. C,D:ppp1r12a and pou5f1 mutants had reduced numbers of αGfap-labeled cell bodies (arrowheads) near the ventricular zone (A; see also Fig. 1E). E-H:gnl3, twistnb, utp11 and mak16 mutants had no αGfap-labeled cell bodies in the ventricular zone. I-L: In contrast, arnt2 mutants had ectopic Gfap+ cell bodies in the floorplate (I), and wnt5b, kif11, and esco2 mutants had increased numbers of Gfap+ cell bodies in the ventricular zone (J-L). M-O:mib, ppp1r12a, and smo mutants all had fewer or no αGfap-labeled cell bodies and radial glial processes. mib mutants had no radial glial processes except in the regions of the roof- and floorplates (M, brackets). N: In ppp1r12a mutants, aberrant axons projections were associated with ectopic dorsal clusters of radial processes (arrows). O: smoothened mutants had no αGfap-labeled cell bodies and generally disorganized radial glial processes.