Fig. 1

Muscles and motor neurons that drive various locomotor behaviors. Schematic of Drosophila larva side view, anterior to left. Mouthhooks far left, black; CNS with anterior brain lobes and ventral nerve cord, grey. Nerves contain sensory input from abdominal segments (small circles) and motor neuron output to muscles (red/green/blue rectangles). The red/green/blue territories represent muscle functional groups containing ~ 10 individual muscles each: red is dorsal longitudinal muscles, green is transverse muscles, and blue is ventral longitudinal muscles. Some of these individual muscles are shown in the same color code in more posterior segments. This larva shows only seven segments for clarity; wild type larvae contain three thoracic segments and eight abdominal segments