Fig. 3. Distribution and movement of starved animals on a temperature gradient. (A) N2 worms were starved for 6 h (upper and middle panels) or overnight (lower panel) and examined for distribution on the temperature gradient. Upper panel, N2 (lab line) starved at 20°C (filled circles; N=83 worms, 3 experiments) or 15°C (open circles; N=84 worms, 3 experiments); middle panel, N2 (CGC line) starved at 20°C (filled circles; N=48 worms, 2 experiments) or 15°C (open circles; N=58 worms, 2 experiments); lower panel, N2 (CGC line) starved at 20°C (N=77 worms, 3 experiments). (B) N2 worms (CGC line) starved at 20°C for 6 h were put on a temperature gradient and movement was observed for about 10 min. Instantaneous velocities and their elements in gradient directions (dots; positive values indicate upward movement; negative values indicate downwards movement) are plotted with their means in each area of the gradient (lines). Results of 2759 points are shown. (C) Examples of traces observed in B are shown with starting points (filled circles), and positions on the temperature gradient (broken lines).