Differential activities of the core planar polarity proteins during Drosophila wing patterning.
During planar polarity patterning of the Drosophila wing, a "core" group of planar polarity genes has been identified which acts downstream of global polarity cues to locally coordinate cell polarity and specify trichome production at distal cell edges. These genes encode protein products that assemble into asymmetric apicolateral complexes that straddle the proximodistal junctional region between adjacent cells. We have carried out detailed genetic analysis experiments, analysing the requirements of each complex component for planar polarity patterning. We find that the three transmembrane proteins at the core of the complex, Frizzled, Strabismus and Flamingo, are required earliest in development and are the only components needed for intercellular polarity signalling. Notably, cells that lack both Frizzled and Strabismus are unable to signal, revealing an absolute requirement for both proteins in cell-cell communication. In contrast the cytoplasmic components Dishevelled, Prickle and Diego are not needed for intercellular communication. These factors contribute to the cell-cell propagation of polarity, most likely by promotion of intracellular asymmetry. Interestingly, both local polarity propagation and trichome placement occur normally in mutant backgrounds where asymmetry of polarity protein distribution is undetectable, suggesting such asymmetry is not an absolute requirement for any of the functions of the core complex.
Strutt
David
D
Centre for Developmental and Biomedical Genetics, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, UK. d.strutt@sheffield.ac.uk
Strutt
Helen
H
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002450:Cell Communication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D000072261:Dishevelled Proteins; D004330:Drosophila / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005123:Eye / Q000254:growth & development; D051157:Frizzled Receptors / Q000235:genetics / Q000378:metabolism; D060588:LIM Domain Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D011679:Pupa / Q000254:growth & development; D015398:Signal Transduction; D014921:Wings, Animal / Q000254:growth & development* / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C492998:Dgo protein, Drosophila; D000072261:Dishevelled Proteins; D029721:Drosophila Proteins; D051157:Frizzled Receptors; D060588:LIM Domain Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; C111638:Vang protein, Drosophila; C000606588:dsh protein, Drosophila; C121600:pk protein, Drosophila