Effects of dhc1b-3 on phototaxis, swimming speed, and flagellar beat frequency. Phototaxis direction of wild-type, agg1, dhc1b-3, and bbs4-1 strains at 21 and 34°C, measured by the bulk migration of cells in dish assays (A) and the swimming trajectory of individual cells (B). For A and B, green light illumination is directed from the right. The compass plots in B indicate the percentage of cells swimming in a particular direction relative to the light source, grouped into 30-degree bins. Swimming speed (C) and flagellar beat frequency (D) of wild-type and dhc1b-3 cells at 21 and 34°C. Reactivated cell models are fixed permeabilized cells that have been treated with ATP, reinitiating flagellar beating (Kamiya and Witman, 1984). Error bars indicate standard deviation.