Figure 2.

Changes in temperature affect the locomotor behavior of flies. Two groups of flies, one Canton S (wild type) and one para^ts1 (temperature sensitive paralytic mutant) are corralled under small petri dish lids resting on top of the metal block of a thermocycler. For each condition, a sequence of four images from the same dish is followed by a composite image created by sliding_window.pl. Canton S flies showed very little movement at 20°C (a) and greatly increased their movement when the heat block heated up to 40°C (b). Para^ts1, on the other hand, moved around at 20°C (c) and, after the paralysis began, showed zero movement at 40°C (d).