Complex Interactions between GSK3 and aPKC in Drosophila Embryonic Epithelial Morphogenesis
Figure 1
Apical-basal components display asymmetric distribution.
(A) Stage 15 epithelium with junctions in green (Arm) and denticle precursors in red (pTyr). Note the rectangular cell shapes of denticle-secreting cells, versus the squamous, irregular shape of cells that do not secrete denticles. Notice also the asymmetric Arm distribution, and actin-based denticle precursors localized to the posterior of cells. (B) A stage 15 ventral epithelium showing polarity protein aPKC enriched at the D/V margins of cells. (C) Schema of a stage 15 embryonic ventral epithelium. The apical components and adherens junction components are asymmetrically distributed to the D/V margins of cells. The baso-lateral components are asymmetrically distributed to the A/P margins of cells. Rectangular cells produce an actin-based precursor at the posterior edge of cells. (D-E) Cuticle of wild-type denticles, with denticle rows properly aligned. (F) Denticle belt of an aPKC mutant, which has very slightly misaligned denticle rows. (G) An embryo overexpressing aPKC also shows little to no phenotype, with very mild denticle misalignment. (H) Ventral epithelium of an aPKC mutant showing that the aPKC protein is still present at cell membranes in the mutant embryo. Anterior to posterior (A/P) and dorsal to ventral (D/V) directions are shown in the schematic (C) and this orientation is maintained in all figures. Scale bar = 20 µm.