Single mesodermal cells guide outgrowth of ectodermal tubular structures in Drosophila.
The Drosophila tracheal system, a tubular network, is formed from isolated ectodermal metameres by guided branch outgrowth and branch fusion. Branch outgrowth is triggered by the localized and transient activity of Branchless (Bnl/dFGF). Here, we report the discovery of a mesodermal cell that links the leading cells of outgrowing main branches 2.5 hr before they fuse. This bridge-cell serves as an essential guidance post and needs Hunchback (Hb) activity to exert its function. The bridge-cell provides cues acting in concert with Bnl/dFGF signaling to mediate directed branch outgrowth that ultimately leads to position-specific branch fusion.
Wolf
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Max Planck Institut für biophysikalische Chemie, Abteilung Molekulare Entwicklungsbiologie, Am Fassberg, D-37077 Göttingen, Germany.
Schuh
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D000818:Animals; D017209:Apoptosis; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D004330:Drosophila / Q000166:cytology / Q000196:embryology*; D029721:Drosophila Proteins; D004475:Ectoderm / Q000166:cytology*; D005346:Fibroblast Growth Factors; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D019476:Insect Proteins / Q000096:biosynthesis; D008648:Mesoderm / Q000166:cytology*; D018613:Microscopy, Confocal; D016296:Mutagenesis; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014132:Trachea / Q000196:embryology; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D001616:beta-Galactosidase / Q000378:metabolism
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D016376:Oligonucleotides, Antisense; D014157:Transcription Factors; C102644:bnl protein, Drosophila; C061245:hb protein, Drosophila; D005346:Fibroblast Growth Factors; D001616:beta-Galactosidase