The lateral LGN complex is required for planar cell division. (a) Spindle orientation in anaphase was measured at E3 in transverse sections of the neural tube 24 h after electroporation. Knockdowns of LGN, NuMA, and Gαi1/2 result in defects in spindle orientation compared with a control RNAi construct targeting luciferase. (b) Top: treatment with the pertussis toxin catalytic subunit (PTx-A) randomizes spindle orientation compared with electroporation with a control Myc-tag expressing vector. Bottom: representative cells with spindle orientation defects in anaphase. H2B-GFP (green) reveals the parting chromosomes in anaphase, β-catenin (red) shows the cell outline and apical surface. (c) Overexpression of Gαi-GDP (Gαi-G203A) results in spindle randomization, whereas Gαolf-GDP (Gαolf-G213A) has no effect. Solid red line in graphs: median angle. Significance was assessed using the Kolmogorov-Smirnov test. There was no significant difference between control conditions (Myc, miLuc, and Gαolf-G213A). All other conditions differed significantly from the controls. n represents the number of measured cells. Data are collected from at least five embryos for each condition. Lightning arrows indicate the electroporated product(s). Bar, 5 µm.