Microtubule orientation in ddaE neurons of DSas-4 mutants is normal. (A) EB1-GFP was expressed in neurons of yw and DSas-4 mutants using 109(2)80 Gal4. Movies of EB1-GFP movement were taken with a confocal microscope. For yw controls, a maximum projection of 41 frames into a single image was performed for the dendrite (top left), and a maximum projection of 7 frames was performed for the axon (top right). For DSas-4 mutants, a maximum projection of 59 frames into a single image was performed for the dendrite (bottom left), and a maximum projection of 18 frames was performed for the axon (bottom right). Arrows show the directionality of EB1-GFP movement. Additional files 7, 8, 9 and 10 show the data from which these figures originate. (B) The directionality of EB1-GFP comets was quantified in class 1 ddaE neurons. The 'n' values are the number of EB1-GFP comets analyzed. In all cases, P > 0.05 (Fisher's exact test), which indicates that the neurons retain their polarity despite loss of DSas-4. (C) DSas-4 mutants exhibit no changes in cell morphology. Live imaging was performed on control and DSas-4 larvae expressing heterozygous EB1-GFP,109(2)80. Dendritic and axonal structures remain similar in both cases. Blue arrows point to the cell body of the ddaE neuron.