Fig. 4.

Postsynaptic, but not presynaptic, SDN causes larval mobility defects. Average crawling speeds for control and SDN-expressing third-instar larvae. Speed decreases by 58% in Sh⁷ larvae (n = 12 vs. CS) and by 68% in larvae expressing SDN panmuscularly (n = 9 vs. CS). Sh⁷ and panmuscular SDN-expressing larvae were indistinguishable (P > 0.2). The motility defect is absent in uninduced MHC-GS SDN controls (n = 11, P > 0.05 vs. CS). When SDN is induced in neurons, no effect on crawling speed is observed (n = 11, P > 0.1 vs. CS or uninduced controls). For all controls, crawling speeds are not significantly different (P > 0.5). All data are mean ± SD. RU, RU-486. **, P < 0.001.