Fig. 4. Lrp6 localizes in a polarized distribution in cells that undergo convergent extension and is adjacent to actin-rich regions in cellular processes. (A) Animal cap cells show uniform distribution of injected VSVG-lrp6 (VSVG-LRP6; 2 ng). In Activin-treated caps the staining of VSVG-Lrp6 is polarized. (B) DMZ explants from VSVG-Lrp6-injected embryos show preferential localization of Lrp6 at the posterior cell edge. High magnification views of cells in the DMZ are shown in the bottom panels. Injection of myristoylated, plasma membrane localized GFP (mGFP; 500 pg) or anti-actin staining was performed as controls for animal cap and DMZ experiments, respectively. Explants are outlined with solid lines to make their borders readily identifiable. (C) Lrp6 is adjacent to actin-rich regions of cellular extensions. DMZ cells injected with VSVG-Lrp6 were dissociated, plated on fibronectin, immediately fixed, and stained with anti-VSVG (green) and phalloidin (red). Scale bars: animal caps, 30 µm; DMZ (40x), 200 µm; high-magnification DMZ (75x), 50 µm; dissociated cells (200x), 20 µm; high-magnification dissociated cells (350x), 5 µm.