MIG-2, but not INA-1, polarizes migrating Q neuroblasts. (A–C) The morphology of migrating QL.ap cell visualizing from the left/right lateral side of C. elegans L1 larva expressing soluble GFP in WT (A), mig-2(rh17) (B), and ina-1(gm144) mutants (C). This GFP marker stains the Q cell periphery and the nucleus. The top panels show the first frames of QL.ap migration from Videos 7–9. Numbers 1, 2, and 3 indicate the QL.ap positions at 0 (1; the first frame), 30 (2), or 60 min (3) during migration from Videos 7–9. QL.ap in mig-2(rh17) (B) or ina-1(gm144) (C) migrates slower and shorter than its migration in WT (A). The bottom three panels show the magnified views of cell morphology of migrating QL.ap paired with schematic diagrams from the top panels or frames in Videos 7–9. Migrating QL.ap properly polarizes the lamellae toward the posterior in WT (A; 100%, n = 15) and in ina-1(gm144) (C; 92%, n = 12). However, in mig-2(rh17), QL.ap forms protrusions in random directions, marked by red asterisks. The anterior (A)–posterior (P) axis is the left to right. Light green, cytoplasm; dark green, nuclei. Bars, 5 µm.