Glial architecture in a wild type adult optic lobe.
Image shows serial sections through an adult optic lobe of a wild type animal of genotype:-
nrv2GAL UAS-mCD8:GFP / +
The nrv2GAL4 line (Sun et al, 1999) drives expression of GFP (green) in glial cells in the adult. The expression pattern of endogenous Ogre protein (Ogre in the optic lobe) overlaps with the nrv2GAL4 pattern and Ogre may be essential for the development/survival of these cells - ogre mutants exhibit extremely small optic lobes lacking nearly all internal nrv2GAL4 directed GFP staining (ogre mutant optic lobe). It's not yet known whether the loss of optic lobe glia is due to the cell proliferation defect in the optic lobe proliferation centers that is reported to underlie the small optic lobes phenotype (Lipshitz and Kankel, 1985)....or whether the loss of glia is another, separate, phenotype arising from loss of Ogre activity in glia after they have been born and established their glial identity. Expression of UAS-ogre in a nrv2GAL4 pattern in ogre mutant flies can partially rescue the optic lobe size and structure phenotypes (see related images below).