Signals beneath the ectoderm: Mesodermal FGF signaling keeps the dorsally closing epithelium in shape

Loss of mesodermal FGF signaling in Drosophila disrupts dorsal closure, transforming straight dorsal seams and epidermis into highly distorted, dynamically changing zigzags.

• Why it matters: Dorsal closure depends on coordinated signaling and mechanics, but how mesodermal FGFR activity stabilizes the ectodermal epithelium during morphogenesis is unclear.
• What they did: The authors examined embryos lacking Pyramus or Thisbe, Heartless, or Stumps, then tested rescue by expressing Heartless in mesoderm versus ectoderm and used mesoderm ablation to intensify seam defects.
• The result: Mesodermal Heartless expression restores epithelial stability in heartless mutants, while ectodermal expression does not; mesoderm ablation causes more extensive distortions that persist past closure, yet closure still completes.

AI summary of the abstract · may contain errors · not medical advice · read the paper.