Wing disc development in the fly: the early stages

The establishment of the wing anlage in Drosophila is dependent on the pres ence of two organizing centers located at the boundaries of the dorsoventra l and anteroposterior compartments. How these boundaries are defined was no t understood until recently. Furthermore, nothing was known about how the h inge region of the wing is defined. Recent data have now started to provide some insight in the molecular processes required for the definition of the major boundaries and subdivision of the wing anlage into the hinge and bla de region.