Fig. 2: MooSEZ gains its rotational functionality following metamorphosis.

A Example trajectories of mosaic larvae (top) and their matched adult flies (bottom) during optogenetic activation (larvae, 9-s; adults, 2-s) of CsChrimson in right (purple), left (yellow), or both MooSEZs (black). CsChrimson was expressed unilaterally or bilaterally using the SPARC “intermediate” effector and under the control of the GH146^II-GAL4 driver line. MooSEZ unilateral activation drives straight backward locomotion in larvae but ipsilateral backward rotation in adult flies. B Single traces (light) of cumulative angular change and their respective means (dark) of larvae (top) and their matched adult flies (bottom) in which MooSEZs were optogenetically activated (larvae, 9-s; adults, 2-s) unilaterally (right, purple; left, yellow) or bilaterally (black). The light pulse is labeled in light red. CsChrimson was expressed unilaterally or bilaterally using the SPARC “intermediate” effector and under the control of the GH146^II-GAL4 driver line. C Mean angular velocity during optogenetic stimulation (larvae, 9-s; adults, 2-s) of the right (purple), left (yellow), or both MooSEZs (black) for the single larvae and their matched adult flies presented in (B). Rotational backward locomotion upon MooSEZ unilateral activation is observed only following metamorphosis. D Left, angular speed ± SEM (shading) of larvae (light blue) and adult flies (dark blue) following a 9-s long bilateral optogenetic stimulation of CsChrimson in MooSEZs driven by GH146^II-GAL4 with subtracted GH146-QF. GH146-QF was used to drive QUAS-GAL80 to limit the expression pattern of GH146^II-GAL4 driving UAS-CsChrimson. The light pulse is labeled by light red. Continuous symmetric MooSEZ activation evokes rotational movements only among adult flies. Right, mean angular speed during the 9-s light pulse obtained from traces on the left. A significant difference is observed between the mean angular speed of larvae and adult flies upon prolonged bilateral light stimulation (n for larva, adult: 8, 18, respectively, ****p < 0.0001, Mann-Whitney test). E Single fly (dark blue) and larva (light blue) traces (light) of absolute cumulative angular change and their respective means (dark) following a 9-s long bilateral optogenetic stimulation of CsChrimson in MooSEZs driven by GH146^II-GAL4 with subtracted GH146-QF. GH146-QF was used to drive QUAS-GAL80 to limit the expression pattern of GH146^II-GAL4 driving UAS-CsChrimson. The light pulse is labeled by light red. Prolonged bilateral MooSEZ activation elicits sustained adult-specific backward rotation. Right, absolute total angular change at the end of the 9-s light pulse obtained from traces on the left. A significant difference is observed between the absolute total angular change of larvae and adult flies (n for larva, adult: 8, 18, respectively, ****p < 0.0001, Mann-Whitney test). For details of statistical analysis, see Supplementary Data 1.