A histological comparison of the original and regenerated tail in the green anole, Anolis carolinensis.

This study provides a histological comparison of the mature regenerated and original tail of the lizard Anolis carolinensis. These data will provide a framework for future studies of this emerging model organism whose genome was recently published. This study demonstrated that the cartilage skeleton of the regenerated tail enclosed a spinal cord with an ependymal core, but there was no evidence that dorsal root ganglia or peripheral nerves are regenerated. The cartilage tube contained foramina that allowed the vasculature to cross, but was otherwise a rigid structure. The original tail has muscle groups arranged in quadrants in a regular pattern that attach to the vertebral column. The regenerated tail has irregular muscle bundles of variable number that form unusual attachments to each other and to the cartilage tube. Furthermore, the data show that there was increased connective tissue within the muscle bundles. Implications for functionality of the regenerated tail and for future biomechanical studies are discussed.