Fig. 1. Proliferation in non-regenerating caudal fin. Zebrafish (n=5) were incubated in BrdU-containing water for 18 hours and BrdU was detected using immunolabeling (red). Posterior is at left and anterior is at right. (A) Whole-mount caudal fin shows abundant labeling concentrated at the posterior end of the fin. Rectangles indicate the approximate site of longitudinal sections. (B) Longitudinal section from the posterior end of intact caudal fin. Note positive labeling of both epithelial and mesenchymal cells (arrowheads). (C) Longitudinal section through the middle of the caudal fin. Note that both epithelial and mesenchymal cells are labeled (arrowheads). e, epithelium; l, lepidotrichia; m, mesenchyme.
