Wingless signaling leads to an asymmetric response to decapentaplegic-dependent signaling during sense organ patterning on the notum of Drosophila melanogaster.
Wnt and Decapentaplegic cell signaling pathways act synergistically in their contribution to macrochaete (sense organ) patterning on the notum of Drosophila melanogaster. The Wingless-signaling pathway was ectopically activated by removing Shaggy activity (the homologue of vertebrate glycogen synthase kinase 3) in mosaics. Proneural activity is asymmetric within the Shaggy-deficient clone of cells and shows a fixed "polarity" with respect to body axis, independent of the precise location of the clone. This asymmetric response indicates the existence in the epithelium of a second signal, which we suggest is Decapentaplegic. Ectopic expression of Decapentaplegic induces extra macrochaetes only in cells which also receive the Wingless signal. Activation of Hedgehog signaling generates a long-range signal which can promote macrochaete formation in the Wingless activity domain. This signal depends upon decapentaplegic function. Autonomous activation of the Wingless signal response in cells causes them to attenuate or sequester this signal. Our results suggest a novel patterning mechanism which determines sense organ positioning in Drosophila.
School of Biological Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom. bafp8@sussex.ac.uk
R G
RG
Phillips
N L
NL
Warner
J R
JR
Whittle
D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D038362:Glycogen Synthase Kinase 3; D053823:Hedgehog Proteins; D007150:Immunohistochemistry; D019476:Insect Proteins / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012679:Sense Organs / Q000196:embryology* / Q000254:growth & development; D015398:Signal Transduction / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics; D051155:Wnt1 Protein
D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D019476:Insect Proteins; D011518:Proto-Oncogene Proteins; D051155:Wnt1 Protein; C047663:cuticle proteins, insects; C064196:dpp protein, Drosophila; C074622:wg protein, Drosophila; C077245:hh protein, Drosophila; D017346:Protein Serine-Threonine Kinases; C080335:Sgg protein, Drosophila; D038362:Glycogen Synthase Kinase 3