Figure 7

Semithin sections and whole mounts of 72 hour tail plate blastemas. Schemes are indicating the orientation of the animal in the respective subpanels. (A-E) Stained after Heidenhain, all pictures from the same series. (A) A regenerated duo-gland adhesive system dg is visible (double arrowhead). Arrowheads denote the regenerated tip of the male genital apparatus mg, consecutive sections showing the composition of this organ in (B-E). (F-H) BrdU pulse, all pictures from the same animal. (F) Whole mount. No accumulation of labeled cells. (G) Section in the area of the regenerating mg (densely blue stained area at the top). No labeled cells (brown) are present in the mg. (H) Section showing a number of labeled cells aside from the mg. (J-L) BrdU pulse-chase. (J) Whole mount, arrowhead points at a labeled epidermal cell. The accumulation of neoblasts in the blastema is evident. (K) Same animal as (J), note the labeled epidermal cells (arrowheads, inset) and the labeled nuclei of the dg (arrow). The regenerating mg is located at the top and shows freckled label in many cells (also see right inset). (L) Horizontal section of a different animal, arrowhead points at the tip of the regenerating mg. (G, H, K, L) stained with methylene blue. Scale bars are 20 μm, (B-E) same scale bar.