Fig. 9

Asymmetric divisions, cell cycle aspects and BrdU clearing time of VO cells in Ph. femoratum. a, c: Walking leg ganglion 4 of last postlarval instar. b, b’, d: Walking leg ganglion 4 of first juvenile instar. Stippled ovals highlight the internal VOs of one body half. Stars indicate the central cavity around which tubulin-rich cell processes converge. a, b: Horizontal optical sections showing phalloidin-F-actin staining (red) in combination with PH3 labeling (yellow) and nuclear counterstain (blue). Black arrows point to mitotic cells with asymmetrically positioned metaphase plates. Black arrowhead marks later stage of an asymmetric division. b’: Higher magnification of a PH3-labeled metaphase plate with distinct shift towards one pole of the cell (the same metaphase is highlighted in b). c, d: Horizontal optical sections showing EdU staining (4 h exposure, red) in combination with acetylated tubulin (white) and PH3 (yellow) labeling and nuclear counterstain (blue). The PH3-positive mitotic cells show no co-labeling for EdU. The white arrow indicates the anterior fibrous strand extending dorsally from the VO. e: VO of last postlarval instar, extended optical section (5 μm) through one hemisphere of walking leg ganglion 3 after double-nucleoside labeling (6 h BrdU, 12 h sea water, 3 h EdU, sacrifice). Detection of BrdU (green) and EdU (red) combined with acetylated tubulin (white) and nuclear counterstain (blue). Black arrows mark selected BrdU+/EdU+ nuclei. White arrowheads highlight some BrdU+/EdU− nuclei. Black arrowheads indicate BrdU−/EdU+ nuclei