Fig. 4. Immunolabelling of the V₁ complex in midgut goblet cells from Manduca sexta. Cryosections from feeding (A; fifth-instar, days 2-3), starving (B; fifth-instar, day 2-3), moulting (C; fourth- to fifth-instar, moulting stage D) and 20-hydroxyecdysone-treated (D; fifth-instar, days 2-3, 24h after hormone injection) larvae were stained with monoclonal antibody 221-9 to V-ATPase subunit A (Klein et al., 1991). Scale bar, 30µm; a, apical; b, basal; g, goblet cell cavity; asterisks indicate goblet cell apical membranes; arrows point to goblet cell nuclei.