A histochemical and immunohistochemical investigation of epimorphic regeneration in the representative lizard, Eublepharis macularius

Abstract

Epimorphic regeneration involves cell proliferation and the formation of a regeneration blastema to replace lost or damaged tissues. Although well described for teleosts and urodeles, this type of regeneration is also characteristic of many lizards. The objective of this study was to investigate the events that characterize epimorphic tail regeneration in the leopard gecko, Eublepharis macularius using both histochemistry and immunohistochemistry. Changes in tissue structure and composition of the regenerating tail were examined at various times post‐tail loss. A phase of wound healing follows immediately after tail loss during which time basal cells of the epidermis proliferate and migrate across the wound site. Once the wound is capped proliferation begins deep to the wound epithelium, giving rise to a localized mass of undifferentiated cells, the regeneration blastema. Blastema formation coincides with the onset of angiogenesis and redevelopment of axons and the ependymal tube of the spinal cord. Skeletal tissues differentiate somewhat later during tail regeneration, matching with the expression of Sox9. We also observe Sox9 expression in both mesenchymal and ependymal cells. Our findings demonstrate the utility of lizard tails as a model system for ongoing studies of epimorphic regeneration.Grant Funding Source: NSERC