Imaging of the terminal cell of the trachea in Drosophila larva. (A) Segmentation of the hollow space inside the tracheal tube (yellow) visualized with a raw image of the FIB-SEM acquisition (gray scale). (B) Overlay of the segmentation of the tracheal tube obtained from the confocal dataset (green) and from the FIB-SEM data (yellow). (C and D) Volume rendering of the inside of the tracheal tube, showing the aECM structures formed in sites of tube branching. (E) FIB-SEM image showing the organization of the basal membranes surrounding the muscle cells (segmentation shown in transparency in magenta) and the tracheal cell (segmented in green). (F) FIB-SEM image showing a cross section of a tracheal cell. Arrowheads point at invaginations of the basal plasma membrane consistent with membrane trafficking activity. (G) 3D visualization of a putative site of fusion of a carrier vesicle containing electron-scattering structures (arrowhead) with the apical plasma membrane of a trachea cell.