Biology Open (Sep 2022)

Focal sources of FGF-10 promote the buckling morphogenesis of the embryonic airway epithelium

  • Kara E. Peak,
  • Shelby R. Mohr-Allen,
  • Jason P. Gleghorn,
  • Victor D. Varner

DOI
https://doi.org/10.1242/bio.059436
Journal volume & issue
Vol. 11, no. 9

Abstract

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During airway branching morphogenesis, focal regions of FGF-10 expression in the pulmonary mesenchyme are thought to provide a local guidance cue, which promotes chemotactically the directional outgrowth of the airway epithelium. Here, however, we show that an ectopic source of FGF-10 induces epithelial buckling morphogenesis and the formation of multiple new supernumerary buds. FGF-10-induced budding can be modulated by altered epithelial tension and luminal fluid pressure. Increased tension suppresses the formation of ectopic branches, while a collapse of the embryonic airway promotes more expansive buckling and additional FGF-10-induced supernumerary buds. Our results indicate that a focal source of FGF-10 can promote epithelial buckling and suggest that the overall branching pattern cannot be explained entirely by the templated expression of FGF-10. Both FGF-10-mediated cell behaviors and exogenous mechanical forces must be integrated to properly shape the bronchial tree.

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