Whole-mount in vitro mitotic labeling of explanted maxillary barbel buds. Nuclei are stained blue; cells in S-phase (EdU+) are also red. Panels A and B are depth-sensitive full-thickness image renderings, in which superficial nuclei appear brighter than deeper ones. Panel C is a similar rendering; for clarity, the membrane-GFP signal has been removed from the superficial layers.
A) Mitotic labeling of a wildtype juvenile barbel (~300 μm). Dividing cells are scattered throughout the appendage.
B) Mitotic labeling of a slightly longer barbel appendage (~500 μm). Clusters of dividing cells on the ventral side of the barbel correspond to the developing taste buds.
C) Mitotic labeling of an elongated juvenile barbel (~1 mm) from a membrane-EGFP transgenic zebrafish. Labeled nuclei are found in both the epithelial and mesenchymal layers throughout the appendage.