Figure 9.

Stage VI of tail regeneration. Stage VI of tail regeneration. Eublepharis macularius. (A,B) Gross morphology of regenerating tail in lateral (A) and dorsal view (B). The regenerating tail is tapering cone with a diameter: length approaching 1.0. Serial sections (dorsal toward the top) stained with Masson's trichrome (C,D,H), Alcian blue (E), immunostained with Sox9 (F) or stained with hematoxylin and eosin (G). (C) Sagittal section of tail. Note that most tissues have fully differentiated and an aggregation of blastema cells is no longer apparent. The cartilaginous cone is anchored to the remnant of original vertebra. (D) Closer view of the region identified in panel (C) taken from a different section. By this stage of regeneration the integument of includes the newly formed dermis. (E,F) Closer view of the region identified in panel (C) taken from a different section. The cartilaginous cone is cell-rich and stains strongly positive for Alcian blue. Differentiating chondrocytes are immunostained (brown) for Sox9. (G) Sagittal section through the distal tip of the tail demonstrating the ependymal tube (stained red) passing through the cartilage cone (stained pink). (H) Longitudinal section through the caudal artery (stained red) of the original tail and regenerate tail. Arrowheads indicate the transition from the original (on the left) to the regenerate caudal artery (on the right). ca, caudal artery; cc, cartilage cone; em, epaxial muscle; et, ependymal tube; hm, hypaxial muscle; no, notochord; ra, regenerated adipose tissue; rd, dermis; sc, spinal cord; sp, arterial sphincter. Scale bars: c = 500 μm; d,e = 20 μm; f,g = 100 μm; h = 50 μm.