Dominant enhancers of Egfr in Drosophila melanogaster: genetic links between the Notch and Egfr signaling pathways.
The Drosophila epidermal growth factor receptor (EGFR) is a key component of a complex signaling pathway that participates in multiple developmental processes. We have performed an F1 screen for mutations that cause dominant enhancement of wing vein phenotypes associated with mutations in Egfr. With this screen, we have recovered mutations in Hairless (H), vein, groucho (gro), and three apparently novel loci. All of the E(Egfr)s we have identified show dominant interactions in transheterozygous combinations with each other and with alleles of N or Su(H), suggesting that they are involved in cross-talk between the N and EGFR signaling pathways. Further examination of the phenotypic interactions between Egfr, H, and gro revealed that reductions in Egfr activity enhanced both the bristle loss associated with H mutations, and the bristle hyperplasia and ocellar hypertrophy associated with gro mutations. Double mutant combinations of Egfr and gro hypomorphic alleles led to the formation of ectopic compound eyes in a dosage sensitive manner. Our findings suggest that these E(Egfr)s represent links between the Egfr and Notch signaling pathways, and that Egfr activity can either promote or suppress Notch signaling, depending on its developmental context.
Price
J V
JV
Institute of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada. jprice@sfu.ca
Savenye
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ED
Lum
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Breitkreutz
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A
D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D002874:Chromosome Mapping; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases; D006579:Heterozygote; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D016296:Mutagenesis; D010641:Phenotype; D051880:Receptors, Notch; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014921:Wings, Animal / Q000254:growth & development
D029721:Drosophila Proteins; D019476:Insect Proteins; D008565:Membrane Proteins; C497759:N protein, Drosophila; D051880:Receptors, Notch; D012097:Repressor Proteins; C088731:Su(H) protein, Drosophila; D066246:ErbB Receptors; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; C086795:rl protein, Drosophila