spalt-induced specification of distinct dorsal and ventral domains is required for Drosophila tracheal patterning.
Morphogenesis of the Drosophila tracheal system relies on different signalling pathways that have distinct roles in specifying both the migration of the tracheal cells and the particular morphological features of the primary branches. The current view is that the tracheal cells are initially specified as an equivalent group of cells whose diversification depends on signals from the surrounding cells. In this work, we show that the tracheal primordia are already specified as distinct dorsal and ventral cell populations. This subdivision depends on the activity of the spalt (sal) gene and occurs prior to the activity of the signalling pathways that dictate the development of the primary branches. Finally, we show that the specification of these two distinct cell populations, which are not defined by cell lineage, are critical for proper tracheal patterning. These results indicate that tracheal patterning depends not only on signalling from surrounding cells but also in the different response of the tracheal cells depending on their allocation to the dorsal or ventral domains.
Franch-Marro
Xavier
X
Institut de Biologia Molecular de Barcelona (CSIC), C/Jordi Girona 18-26, 08034 Barcelona, Spain.
Casanova
Jordi
J
D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning / Q000235:genetics; D004330:Drosophila / Q000196:embryology* / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D018398:Homeodomain Proteins / Q000235:genetics*; D007763:Lac Operon; D008954:Models, Biological; D015398:Signal Transduction; D014132:Trachea / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*
D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; C085793:salm protein, Drosophila; C098131:unpg protein, Drosophila