Fig. 4

Adult salivary gland cellular architecture of Drosophila melanogaster. Maximum intensity projection (MIP) or single slice confocal images of female (a) or male (b-c) Drosophila melanogaster adult SGs stained with DAPI, Phalloidin, and WGA. Shown in Ai is an entire female adult SG. Cropped images are shown for the duct/proximal SG (Aii), central region (Aiii), and the distal coiled region (Aiv). Actin signal is less well organized in much of this SG (Aiii), compared to Fig. 4b. Large WGA stained granules are seen in many SG cells (Aiv), and the apical face of the cells, which defines the lumen, stains weaker and appears disorganized and/or not present in the distal coiled region (Av, compare yellow and white arrows). Bi shows a nearly complete male Drosophila SG. Nuclei are in close proximity to the duct in the ID, and taenidial rings are visible (inset). The proximal end of the SG appears to be constricted due to a muscle wrapping around it (Bii). The salivary lumen (WGA) appears wider near the proximal end (Biii). Five cells were consistently seen surrounding the lumen in cross-sections over the full length of the gland (Biv). Bv highlights the distal coiled region, where phalloidin appears enriched, and is seen in fibers running mostly apico-basally within each cell. Some cells show less actin filament organization. WGA (chitin) nicely illustrates the apical surface/lumen (Bvii, white arrow). In the image of a SG attached to the head (c), the green structure labeled muscle (Bi) was confirmed to be muscle based on the striated actin pattern and multiple nuclei not separated by cell membranes (c, white arrows). Scale bar lengths are: 50 microns—Ai, Av, Bi, Bii, C; 20 microns—Aii, Aiii, Biv; 10 microns—Bi-inset, Biii, Bv