Cell and fibronectin dynamics during branching morphogenesis
Open Access
- 15 August 2006
- journal article
- Published by The Company of Biologists in Journal of Cell Science
- Vol. 119 (16), 3376-3384
- https://doi.org/10.1242/jcs.03079
Abstract
Branching morphogenesis is a dynamic developmental process shared by many organs, but the mechanisms that reorganize cells during branching morphogenesis are not well understood. We hypothesized that extensive cell rearrangements are involved, and investigated cell migration using two-color confocal time-lapse microscopy to image cell and extracellular-matrix dynamics in developing salivary glands. We labeled submandibular salivary gland (SMG) epithelial cells with green fluorescent protein and matrix with fluorescent fibronectin. Surprisingly, we observed substantial, rapid and relatively random migration of individual epithelial cells during branching morphogenesis. We predicted that cell migration would decrease after formation of acini and, indeed, found that rapid cell movements do not occur in SMG from newborn mice. However, in embryonic SMG epithelial cells, we observed an absence of choreographed cell migration, indicating that patterned cell migration alone cannot explain the highly ordered process of branching morphogenesis. We therefore hypothesized a role for directional fibronection assembly in branching. Washout and pulse-chase experiments revealed that older fibronectin accumulates at the base of the clefts and translocates inwards as a wedge, with newer fibronectin assembling behind it. These findings identify a new mechanism for branching morphogenesis involving directional fibronectin translocation superimposed on individual cell dynamics.Keywords
This publication has 29 references indexed in Scilit:
- Watching tubules glow and branchCurrent Opinion in Genetics & Development, 2005
- The Role of GDNF/Ret Signaling in Ureteric Bud Cell Fate and Branching MorphogenesisDevelopmental Cell, 2005
- Spatiotemporal regulation of morphogenetic molecules during in vitro branching of the isolated ureteric bud: toward a model of branching through budding in the developing kidneyDevelopmental Biology, 2004
- Cell Migration: Integrating Signals from Front to BackScience, 2003
- Fibronectin requirement in branching morphogenesisNature, 2003
- Building epithelial architecture: insights from three-dimensional culture modelsNature Reviews Molecular Cell Biology, 2002
- Regulation of cadherin junctions during mouse submandibular gland developmentDevelopmental Dynamics, 2002
- In Vivo Imaging Reveals Different Cellular Functions for FGF and Dpp Signaling in Tracheal Branching MorphogenesisDevelopmental Cell, 2002
- EGF-dependent lobule formation and FGF7-dependent stalk elongation in branching morphogenesis of mouse salivary epithelium in vitroDevelopmental Dynamics, 1999
- Purification of FibronectinCurrent Protocols in Cell Biology, 1999