Fig. 2. Characterization of the optic lobe phenotypes of Drosophila babo mutants. (A) A wild-type yw white prepupa showed a large cap structure of lamina neurons (arrowheads) and lamina neuron precursor cells in the lamina cartridge (arrow). (B) The strongest babo^32/52 mutants have a very reduced number of lamina cap (arrowheads) and cartridge neurons (arrows), as revealed by Dachshund antibody (green) and Elav antibody (red) staining. (C) A wild-type yw wandering third-instar larva stained for Robo (green) and Elav (red). The arrowheads point to the lamina cap neurons, whereas the arrow points to the medulla neuropil (bracket of white dots). (D) A babo^32/52 mutant displayed a small lamina cap (arrowheads) and an aberrant medulla neuropil (arrow and white dots). (E) Normal distribution of glial cells labeled by repo antibody (green) in a brain lobe of a wild-type white prepupa. (F) A brain lobe of a babo^32/52 white prepupa, showing a reduced number of glial cells at both the lamina and medulla. (G,H) N-Cadherin (red) and 24B10 (photoreceptors green) staining of the optic lobe region from a yw white prepupae (G) and a babo^26/32 mutant (H). (I,J) The same images as G and H but red channel (N-Cadherin) only. Arrows mark photoreceptors and arrowheads the medulla neuropil. Note that overall intensity of N-Cadherin is not changed in either the photoreceptors or medulla neuropil, but the medulla neuropil is much smaller. la-g, glial cells at lamina; me-g, glial cells at medulla.