In adults, enhancer trap expression is observed in glia of the laminal and medullar regions of the optic lobes. The laminar glia appear to correspond to the marginal glia, epithelial glia, satellite glia, and subretinal cells. In third instar larvae, expression is also restricted to glial cells and is observed in the eye disc and in a region that develops into the optic lobe in the larval brain. In embryos, enhancer trap expression was observed in many of the glia of the CNS and PNS but not in the midline glia. Expressing cells include the longitudinal glia, exit glia, peripheral glia, and nerve root glia.