Fig. 5. Activation of the Hh pathway is revealed with the phospho-Cos2 antibody. All pictures are wild-type embryos at stage 10-11. (A) En is in red and S572P-Cos2 is revealed in green. Notice that the phospho-Cos2 labelling is only present in Hh-producing cells (in red) and in adjacent cells. (B) Staining with the antibody recognising the heptad repeats of Cos2 (red, single channel in D); S572P-Cos2 is green (single channel in C). (E) Magnification (x1260) of one abdominal segment (delimited in by the square in B) showing the complementary Cos2 (red) and S572P Cos2 (green) staining. (F-H) Confocal x/y sub-apical sections (magnification x1890) of one segment from wild-type stage 11 embryos. S572P-Cos2 (F-H) is green, Ci (G) is red, Smo (H) is pink and Nrt (F) is blue. No overlap of S572P-Cos2 with Ci (G), Smo (H) or with the plasma membrane marker Nrt (F) could be detected. S572P-Cos2 labelling is mainly cytoplasmic. White line delimits the Hh-expressing and -receiving cells.