The canonical Wg and JNK signaling cascades collaborate to promote both dorsal closure and ventral patterning.
Elaboration of the Drosophila body plan depends on a series of cell-identity decisions and morphogenetic movements regulated by intercellular signals. For example, Jun N-terminal kinase signaling regulates cell fate decisions and morphogenesis during dorsal closure, while Wingless signaling regulates segmental patterning of the larval cuticle via Armadillo. wingless or armadillo mutant embryos secrete a lawn of ventral denticles; armadillo mutants also exhibit dorsal closure defects. We found that mutations in puckered, a phosphatase that antagonizes Jun N-terminal kinase, suppress in a dose-sensitive manner both the dorsal and ventral armadillo cuticle defects. Furthermore, we found that activation of the Jun N-terminal kinase signaling pathway suppresses armadillo-associated defects. Jun N-terminal kinase signaling promotes dorsal closure, in part, by regulating decapentaplegic expression in the dorsal epidermis. We demonstrate that Wingless signaling is also required to activate decapentaplegic expression and to coordinate cell shape changes during dorsal closure. Together, these results demonstrate that MAP-Kinase and Wingless signaling cooperate in both the dorsal and ventral epidermis, and suggest that Wingless may activate both the Wingless and the Jun N-terminal kinase signaling cascades.
McEwen
D G
DG
Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, Department of Biology, The University of North Carolina, Chapel Hill, NC 27599-3280, USA.
Cox
R T
RT
Peifer
M
M
D000818:Animals; D051186:Armadillo Domain Proteins; D019521:Body Patterning / Q000502:physiology*; D004330:Drosophila / Q000196:embryology* / Q000235:genetics / Q000502:physiology; D029721:Drosophila Proteins; D004789:Enzyme Activation; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D016296:Mutagenesis; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D015534:Trans-Activators; D014157:Transcription Factors; D051155:Wnt1 Protein
C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D051155:Wnt1 Protein; C064196:dpp protein, Drosophila; C074622:wg protein, Drosophila; C117694:Hep protein, Drosophila; D020929:Mitogen-Activated Protein Kinase Kinases; C110854:puc protein, Drosophila; D010749:Phosphoprotein Phosphatases