Fig. 4. Neural injury-associated glial cell division. (A) Schematic of the antennal ablation. An antenna on the right side was ablated from the first antennal segment. (B) Antennae were ablated soon after eclosion, and the flies were fed BrdU for 3 days. Antennal ablation induced BrdU incorporation into glial cells (REPO-positive, arrowhead) even though neuronal PCD was inhibited by p35. (C) Percentage of the antennal nerves with BrdU-positive cells. Colour coding indicates the percentage of antennal nerves with the indicated numbers of labelled cells. int, antennal nerves with intact antennae; abl, antennal nerves with antennae ablated just after eclosion. elav-p35, 3-day BrdU treatment; +/+, wild type (CS), 5-day BrdU treatment; eiger¹, homozygous eiger mutant, 5-day BrdU treatment. ^**, P<0.01 (Fisher's exact test). The sample number (n) is indicated above each bar. (D) Schematic of the needle stab. After feeding the flies with BrdU for 1 day, a needle was inserted into the brain, and the flies were fed BrdU for another day before fixation. (E) Projection of confocal optical sections of the frontal half of the brain. Dashed lines outline the brain. BrdU-positive cells were found around the region of injury. (F) An optical section of the area indicated in E (boxed). A montage of confocal bright-field and immunostaining images. BrdU-positive cells were REPO-positive but ELAV-negative, showing that they were glia (arrowheads). Asterisk indicates the site of injury. Scale bars: 50 µm in E; 10 µm in B,F.