Fig. 5. Behavior of mutant worms on a temperature gradient. Wild-type N2 (CGC) or mutant worms were fed at 20°C and transferred onto a temperature gradient. (A) Population distribution after 1 h or (B) means of instantaneous velocities (filled circles) and their elements in gradient directions (open circles; positive values indicate upward movement; negative values indicate downwards movement) at each position of the gradient observed during 10 min were determined. In A, the following alleles were used, and results of 2-4 experiments were combined: tax-2(ks10), tax-4(p678) (solid line); tax-4(ks11) (broken line); egl-4(ks61), eat-4(ad572) (solid line); eat-4(ky5) (dashed line); ttx-3(ks5) (solid line); ttx-3(tm268) (dashed line); and tax-6(p675) (solid line). In B, the total numbers of analysed intervals were as follows: N2, 3743; tax-2(ks10), 723; tax-4(p678), 2607; eat-4(ad572), 984; ttx-3(ks5), 2337; tax-6(p675), 1724; lin-11(n389);him-5(e1467), 731.