UNC-5 and UNC-6 but not UNC-40 are required for dorsal F-actin polarity. (A) VAB-10ABD::GFP accumulation at the dorsal edge of a wild-type VD growth cone (arrows). Ventral region of the growth cone with little VAB-10ABD::GFP accumulation (arrowheads). (B) mCherry growth cone volume marker. (C) Merge. Dorsal is up and anterior is left. (D–G) A representative line plot of a wild-type VD growth cone as previously described (Norris and Lundquist 2011). (D) A graph representing the pixel intensity ratio (arbitrary units) of GFP/mCherry (y-axis) against the distance from the dorsal growth cone edge. (E) For each growth cone, five lines were drawn as shown and the pixel intensity ratios were averaged (error bars represent SD). (F) The average dorsal-to-ventral ratio of GFP/mCherry in wild-type from multiple growth cones (≥15). Error bars represent the SEM of the ratios from different growth cones. (G) Growth cones were divided into dorsal and ventral halves, and the average intensity ratio of VAB-10ABD::GFP/mCherry was determined for each half and represented in (F). (H) The average dorsal-to-ventral ratio of GFP/mCherry from multiple growth cones (≥12) from different genotypes. Asterisks (*) indicate the significance of difference between wild-type and the mutant phenotype (* P < 0.05) (two-tailed t-test with unequal variance between the ratios of multiple growth cones of each genotype). Error bars represent the SEM (I–K) Representative merged images of VD growth cones with cytoplasmic mCherry in red (a volumetric marker) and the VAB-10ABD::GFP in green. Areas of overlap are yellow. Dashed lines indicate the perimeter of the growth cone. Bar, 5 μm.