Fig. 2. Expression of Dll in the embryonic Drosophila brain. Dorsal view of a late stage Drosophila embryo stained for Dll (green), the glial marker RK2 (red) and the axonal marker Fasciclin 2 (blue). (A) Low-magnification view of entire embryo with the two lobes of the brain indicated by arrows. (B,B') High magnification views of the brain where Dll is expressed in neurons (n) in the brain, as well as some of the glia lining a transverse axon commissure. These glia, indicated by arrowheads, also express RK2 and therefore are yellow in B.