Extended Data Fig. 9: The F-Cell is associated with the tactile bristle of the adult fly.

(a) 3D morphology of the tactile bristle at 88-90 hAPF. The F-Cell shows extensive contacts with the socket cell and reduced contact with the shaft cell at this stage. The shaft cell cytoplasm (arrow) is retracting from the dendrite tip (arrowhead). See Supplementary Video 7. (b) 3D morphology of the tactile organ at 95 hAPF (that is, immediately before eclosion of the adult fly). The F-Cell shows extensive contacts with the socket cell and reduced contact with the shaft cell at this stage. The shaft cell cytoplasm (arrow) has retracted further away from the dendrite tip (arrowhead) and is displaying an apoptotic morphology. See Supplementary Video 8. (c) Time course of the death of the shaft cell. Cells are marked by the expression of neur > RFP. Inverted time-lapse confocal images showing condensation and fragmentation of the shaft cell nucleus (arrowhead). Note that the F-Cell is detectable next to the socket cell also at 96 hAPF. (d) SBF-SEM images of the adult bristle. Note that the F-Cell is ensheathing the socket cell. Results are representative of two (a,b) and three (c,d) independent experiments. See Supplementary Video 9. Scale bar is 5 μm. Full genotypes are listed in Supplementary Table 1.