Figure 6. COPI is required for PSG tube expansion.

(A) Western blotting of second-instar silkworm larvae injected with GFP dsRNA (left two lanes) or γ-COP dsRNA (right three lanes). Relative protein expression levels of γ-COP, with tubulin as a reference control, are shown as the column. (B) Second-instar silkworm PSG microphotographs, with arrows indicating the glandular luminal diameter. Calculated diameters of PSG lumen in silkworms injected with GFP or γ-COP dsRNAs are shown in the right bar graph. (C) Western blotting shows suppressed expression of the α-COP (left) and β′-COP (right) by RNAi in third-instar silkworm larvae. Relative protein expression levels of α- and β′-COP, with tubulin as a reference control, are shown. (D) Silkworm PSG microphotographs in third-instar silkworms injected with GFP, α-COP, or β′-COP dsRNAs. Arrows indicate glandular luminal diameter. Statistical calculation of PSG luminal diameters are shown in the right bar graph. Scale bars represent 100 µm.