FIGURE 7:

Csk is in close proximity with overexpressed Gliotactin at the AJ. High-magnification images (60×) from the wing pouch with transgenes or RNAi lines expressed by the apterous-GAL4 (ap>) driver. PLA signals between Gliotactin and Csk (red), immunolabeling for Mcr (green), and labeling for DAPI (blue) or Ecad (blue). Dashed lines mark the apterous boundary where the apterous side (dorsal compartment) is on the left. Each panel represents a single Z slice at the septate junction level. Scale bars: 15 µm. n = 10 except n = 12 disks in A. (A) ap>Gli-WT. PLA signals for Gliotactin + Csk were increased compared with the control side (A and A″). A single Z slice at the level of the AJ is shown with some peripodial membrane immunolabeling from apical layers present (asterisk). (B) In the corresponding side projections, the PLA signals were concentrated at the apical side at the level of the AJ (arrow) (B″) with a smaller degree of PLA in the basal side. (C) ap>Gli-WT, Csk-WT. Coexpression of Csk-WT increased the Gliotactin+Csk PLA in the apterous side (C and C″). A single Z slice at the level of the AJ is shown with some peripodial membrane immunolabeling from apical layers present (asterisk). (D) Corresponding side projections. PLA signals were concentrated in the apical side at the level of the AJ (arrow) (D″) with a smaller degree of PLA in the basal side. (E) ap>Gli-WT, Csk-RNAi. PLA signals between Gliotactin+Csk is decreased when the Csk was knocked down (E and E″). The apterous boundary is in these disks is hard to determine and was not marked. Note that this panel is a single Z stack taken from the columnar epithelium at the septate junction level. (F) Corresponding side projections. (G) Statistical analysis of the Gliotactin+Csk PLA signal intensities in ap>Gli-WT and ap>Gli-WT, Csk-WT. The mean ratios of PLA intensities in the apterous side vs. WT side are shown. n = 12 disks in ap>Gli-WT and n = 10 disks in ap>Gli-WT, Csk-WT (****p < 0.0001). Error bars represent the SD.