(A–G) High-magnification optical sections through secretory cells. (A–E) Immunohistochemical staining of CpMRP (green) in fixed secretory cells. CpMRP staining was confined to intracellular Bodipy-stained membrane structures and displayed a distinct reticular pattern. (B) Extracted cutouts of (A and C) optical section through the nucleus, (D) optical section above the nucleus of the secretory cell, (E) 3D stack displaying CpMRPs primarily spherical distribution. (F and G) CDCFDA staining for vacuolar esterase activity (green) in live cells. A multitude of vacuoles are present that vary in their enzyme content. Bi = basal infoldings, C1 and C2 = canal cells, Cc = cuticular canal, Mv = microvilli, Nc1, Nc2 = nucleus of canal cells, Nep = nuclei of epithelium cells, Re = extracellular room, V = vacuole, Blue, nuclear staining; Red, Bodipy-stained intracellular membrane; Magenta, false color-coded autofluorescence. Scale bars, 20 µm or 5 µm (insets).