Meeting Abstract

78.4  Wednesday, Jan. 6  Reparative regeneration in a novel amniote model MCLEAN, K.E.*; VICKARYOUS, M.K.; Univ. of Guelph, Guelph ON; Univ. of Guelph, Guelph ON kmclean@uoguelph.ca

Reparative regeneration is a dramatic phenomenon in which lost or injured structures and tissues are redeveloped. In extreme cases, reparative regeneration can reproduce entire appendages. We investigated the tissue level events that occur throughout redevelopment of the tail in the leopard gecko, Eublepharis macularius. Changes in tissue structure and composition of the regenerating tail were investigated at various times throughout regeneration using histochemistry and immunohistochemistry. Tail regeneration begins with a latent period during which time wound healing takes place. Once the wound is capped by epithelium proliferation begins, forming an aggregation of mesenchymal-like cells known as the regeneration blastema. Continued growth of the blastema is matched with angiogenesis, and regeneration of the nervous system (e.g., the ependymal tube and peripheral nerve axons). The skeleton is one of the last organ systems to form, although vertebrae are never redeveloped. Instead a cone-shaped cell condensation forms around the regenerating ependymal tube. This condensation matures into a cell-rich, matrix-poor cartilage that continues to proliferate during tail growth, primarily along the periphery and distal end of the cone. Our findings indicate that while the initial events of reparative regeneration are highly conserved among tetrapods, subsequent patterning gives rise to a functionally similar but structurally distinct appendage.