Antagonistic and cooperative actions of the EGFR and Dpp pathways on the iroquois genes regulate Drosophila mesothorax specification and patterning.
In Drosophila, restricted expression of the Iroquois complex (Iro-C) genes in the proximal region of the wing imaginal disc contributes to its territorial subdivision, specifying first the development of the notum versus the wing hinge, and subsequently, that of the lateral versus medial notum. Iro-C expression is under the control of the EGFR and Dpp signalling pathways. To analyze how both pathways cooperate in the regulation of Iro-C, we isolated several wing disc-specific cis-regulatory elements of the complex. One of these (IroRE(2)) integrates competing inputs of the EGFR and Dpp pathways, mediated by the transcription factors Pointed (downstream of EGFR pathway) and Pannier/U-shaped and Mothers against Dpp (Mad), in the case of Dpp. By contrast, a second element (IroRE(1)) mediates activation by both the EGFR and Dpp pathways, thus promoting expression of Iro-C in a region of elevated levels of Dpp signalling, the prospective lateral notum near the anterior-posterior compartment boundary. These results help define the molecular mechanisms of the interplay between the EGFR and Dpp pathways in the specification and patterning of the notum.
Letizia
Annalisa
A
Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Cantoblanco, 28049 Madrid, Spain.
Barrio
Rosa
R
Campuzano
Sonsoles
S
D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism; D004330:Drosophila / Q000196:embryology* / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D016296:Mutagenesis; D009419:Nerve Tissue Proteins / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D018010:Receptors, Invertebrate Peptide / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000502:physiology*; D013909:Thorax / Q000196:embryology*; D014157:Transcription Factors / Q000378:metabolism
D017931:DNA Primers; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; C112506:MAD protein, Drosophila; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D018010:Receptors, Invertebrate Peptide; D014157:Transcription Factors; C099258:caup protein, Drosophila; C064196:dpp protein, Drosophila; C109259:pnr protein, Drosophila; C083884:pnt protein, Drosophila; D011494:Protein Kinases; C066532:Egfr protein, Drosophila; D066246:ErbB Receptors