Fig. 2. REPO activates the expression of the ftz HDS reporter gene in glial cells. (A,D) Wild-type embryos; (B,E) repo mutant embryos; (C,F) ectopic expression of repo in scabrous-GAL4/UAS-repo. (A-C) Stage 16 embryonic PNS preparations. (A) In wild-type embryos, expression of the ftz HDS reporter gene is detected in glial cells of the peripheral nervous system, including the support cells of the bipolar dendritic neuron, peripheral glia, ligament cells of the chordotonal organ and exit glia. (B) In the repo mutant, the expression of the ftz HDS reporter gene in the PNS was absent or dramatically reduced. (C) In response to the ectopic expression of REPO, many cells in the dorsal epidermis expressed the ftz HDS reporter. (D-F) Dissected stage 16 embryonic CNS preparations. (D) In the wild-type CNS, the ftz HDS reporter gene is expressed in a subset of longitudinal glia, the A glia, B glia and intersegmental nerve root glia. (E) In the repo mutant, the expression of the ftz HDS reporter gene in the CNS glia was greatly reduced, as it was in the PNS. (F) Ectopic expression of REPO did not induce ectopic expression of the ftz HDS reporter gene within the CNS, although many cells showed ectopic expression in the periphery. Anterior is leftwards.