Editors' ChoiceDevelopment

Cell Fate in Fly Wings Specified by DER

Science's STKE  07 Dec 1999:
Vol. 1999, Issue 11, pp. tw1
DOI: 10.1126/stke.1999.11.tw1

The spatially and temporally restricted expression pattern of the Drosophila epidermal growth factor receptor (DER) during wing development has implicated this receptor in the specification of vein cell fate. Martin-Blanco et al. report that activity of the DER-specific Ras-Raf-Map kinase (MAPK) pathway correlated with the expression pattern of DER, and that a switch in DER signaling is necessary for normal wing development. By interfering with DER signaling activity through the expression of mutant proteins, the authors found that in the early larval stage, the DER pathway is activated in regions destined to become vein cells. Then, in the early pupal stage, DER expression and MAPK activity decreased in this putative vein region. This reduction was necessary for the cells to differentiate into vein cells. In parallel, DER expression and MAPK activity increased in adjacent intervein regions of the wing. DER signaling was required for the production of Argos, a secreted inhibitory ligand for DER. The authors propose that Argos diffuses from the putative vein region to the adjacent intervein region of the wing and suppresses vein cell fate. In addition, during pupal stages, reduced MAPK activity was required for expression of decapentaplegic, a transforming growth factor β-like protein that is required for vein cell differentiation. Hence, suppression of the DER signal transduction pathway appears necessary for determining vein cell identity.

Martin-Blanco, E., Roch, F., Noll, E., Baonza, A., Duffy, J.B., and Perrimon, N. (1999) A temporal switch in DER signaling controls the specification and differentiation of veins and interveins in the Drosophila wing. Development 126: 5739-5747. [Online Journal]