Fig. 6.

A specialized membrane domain in mesodermal cells. (A, B) Confocal images of the ventral furrows in hand-sectioned wild-type embryos stained for aPKC (green), Dlg (red), Par6 (red), and Ptyr (green) proteins. The panels on the right show a set of ectodermal cells from the same embryo. aPKC (A), Dlg (A′), and Par6 (B) localize to a broad apical region in mesodermal cells, while an unidentified phosphotyrosine epitope (B′) is concentrated apically in a similar manner as Armadillo. A′′ and B′′ are merged images of panels A and A′ and B and B′, respectively. Magnification, ×63; scale bar, 12 μm. (C, D) Distribution of E-cadherin (ECad) (green) in comparison to the evenly distributed membrane protein neurotactin (NRT) (red). (C) Confocal image in a hand-sectioned embryo costained for E-cadherin and neurotactin used for the measurement of line profiles shown in panel D. The images were inverted in Photoshop, and the bottom panel shows a merged image. (D) Thirty-nine fluorescence intensity line profiles for E-cadherin (blue) and neurotactin (red) were measured along the membrane of mesodermal cells on confocal sections of 7 different embryos from apical to basal (measured length = 20 μm, total cell length = 40 μm). The average of single-pixel intensities (y axis, 1 pixel = 102.899 nm) is plotted against distance (x axis, μm). Magnification, ×60; scale bar, 12 μm.