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Fig. 2
Proteins Associated with Lamellipodia and Filopodia, Detected in Apical and Basolateral Locations of the Radial Glia
(A) Hierarchical clustering for proteins associated with lamellipodia and filopodia, revealing that some of them display age-related changes.
(B–V′) Lipofections in vivo were performed and imaged after fixation as whole-mount preparations or as sections (Q–S). (B–D) Overview of one telencephalic hemisphere visualized from the top onto the dorsal surface as a maximum-intensity projection. (B) Cell bodies of the radial glia are labeled by the gfap:GFP transgene. (C) A small, variable number of cells per brain were labeled by the in vivo lipofection (maximum 12 cells per brain); their somata and branched radial processes into the parenchyme are visible (inset is a higher magnification), revealing the soma at the top (apical side) and the radial process in the parenchyme with numerous branches. All lipofected cells displayed this radial process, but it is not visible on all pictures. (D) Merged channels. (E–G) Apical surface of one radial glia, viewed from the top, depicting the existence of lamellipodia extending laterally (arrow in F and G). (H–J) Apical surface of one radial glia, depicting the existence of filopodia (arrow in I and J). (K–M) Filopodia are also extending from the basolateral cell surface toward apical locations on neighboring cells (arrow in L and M). (N–P) The longest filopodia span below 4 cell diameters. (Q–S) lipofection with Lifeact-RFP also reveals basolateral extensions (arrows in R and S). (T–V) Apical view on a cell co-lipofected with the membrane-localized Lyn-GFP (T) and the F-actin localized Lifeact-RFP (U) revealing the presence of filopodial extensions with F-actin (yellow arrows) or without (white arrow). (V′) Lateral view of the same cell. Green lines in (K), (N), and (Q) depict the ventricular surface. Scale bars, 100 μm (D) and 10 μm (G, J, M, P, S, and V).