Fig. 3

Development of the antennal olfactory sensory neurons (OSNs). Volume renderings from confocal image stacks of the reporter signal in the antenna at different developmental stages within the Orco-GAL4xUAS-DsRed line. The dashed lines depict the outline of the antenna based on the autofluorescence of the cuticula. A, B In the last larval instar (LL), OSNs innervate the placoid and the distal trichoid sensillum. C The OSNs retract from the larval antenna during the prepupa (PP) and are with the onset of metamorphosis found at the distal end of the adult antenna. E–G Their number rises until P50% when their distribution already resembles the adult antenna. Scale bars A, B 25 μm; C–G 100 μm. Two time-lapse videos of approx. the first 30 h of OSN-development are available as Additional file 3: Video S1 and Additional file 4: Video S2