Quantitative analysis of the migration pattern of NSPCs expressing mutant forms of Rho GTPases after transplantation. (A) Schematic representation of the compartments defined by their distance from the injection site. Cells were grouped by their localization either within the white matter or the gray matter. Spinal cords were further subdivided into the proximal compartment, rostral distal compartment, and caudal distal compartment. The proximal compartment is the area within 250 μm from the injection sites. (B) Number of cells in the white matter or the gray matter. Preferential localization of transplanted cells in the white matter was observed in all NSPCs expressing CA or DN forms of Rho GTPases, except NSPCs expressing RhoCA. No surviving cells were detected in transplantation of NSPCs expressing RhoCA. (C-F) Migratory profiles of transplanted NSPCs expressing reporter genes (C) or mutant forms of Rho GTPases cdc42 (D), rac1 (E), and rhoA (F). In spite of the differences in the total number of surviving cells, the overall profiles of cell migration were similar in cells expressing mutant Rho GTPases. (G) Mean migratory distance of surviving NSPCs 7 days after transplantation. Cells expressing mutant forms of Rho GTPases showed a similar extent of migration along the rostrocaudal axis except for RhoCA. (H) Morphology and differentiated phenotype of transplanted cells expressing both RhoDN and RacDN. Ramified processes extended from the GFP-positive cell bodies and these structures were immunopositive with an oligodendrocyte marker RIP (arrows). Bar, 20 μm.