Wingless and Hedgehog pattern Drosophila denticle belts by regulating the production of short-range signals.
The secreted proteins Wingless and Hedgehog are essential to the elaboration of the denticle pattern in the epidermis of Drosophila embryos. We show that signaling by Wingless and Hedgehog regulates the expression of veinlet (rhomboid) and Serrate, two genes expressed in prospective denticle belts. Thus, Serrate and veinlet (rhom) partake in the last layer of the segmentation cascade. Ultimately, Wingless, Hedgehog, Veinlet (an indirect activator of the Egfr) and Serrate (an activator of Notch) are expressed in non-overlapping narrow stripes. The interface between any two stripes allows a reliable prediction of individual denticle types and polarity suggesting that contact-dependent signaling modulates individual cell fates. Attributes of a morphogen can be ascribed to Hedgehog in this system. However, no single morphogen organises the whole denticle pattern.
Alexandre
C
C
National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
Lecourtois
M
M
Vincent
J
J
D000818:Animals; D019521:Body Patterning; D002135:Calcium-Binding Proteins; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins; D019476:Insect Proteins / Q000235:genetics*; D036341:Intercellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D051155:Wnt1 Protein
D002135:Calcium-Binding Proteins; D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; C081481:Rho protein, Drosophila; C000606278:Ser protein, Drosophila; D000072099:Serrate-Jagged Proteins; C472498:Stet protein, Drosophila; D051155:Wnt1 Protein; C074622:wg protein, Drosophila; C077245:hh protein, Drosophila