1. Interior cells are frequently migratory and protrusive within the multilayer.
Interior cells are frequently migratory and protrusive within the multilayer. All cells were labeled with Cell Tracker Red and a subset of cells were labeled with an adenovirally delivered cytoplasmic GFP. Images depict 3D reconstructions of the cytoplasm in individual GFP-positive cells. (A) Interior cells were frequently highly migratory and could move in directions opposite to the direction of ductal elongation. (B) Interior cells extended and retracted cytoplasmic protrusions within the multilayer, but not into the lumen or ECM. (C) Individual cells migrated from the interior to basal positions in contact with the ECM, a process termed radial intercalation. (D,E) Cells in contact with the basal tissue surface (D) or both apical and basal tissue surfaces (D,E) extended cytoplasmic protrusions from all lateral surfaces. The movies used to generate A–E are presented in supplementary material Movies 1–5, respectively.
Andrew J. Ewald et al. J Cell Sci 2012;125:
© 2012.