Aided by stem cells, a lizard regenerates a perfect tail for the first time in 250 million years

Regenerated lizard tail — Histology of a fully regenerated mourning gecko tail. Muscle is colored in white, cartilage in red, proliferating cells in green, and cell nuclei in blue. (Image by Lozito Lab)

Lizards can regrow severed tails, making them the closest relative to humans that can regenerate a lost appendage. But in lieu of the original tail that includes a spinal column and nerves, the replacement structure is an imperfect cartilage tube. Now, for the first time, a USC-led study in Nature Communications describes how stem cells can help lizards regenerate better tails.

“This is one of the only cases where the regeneration of an appendage has been significantly improved through stem cell-based therapy in any reptile, bird or mammal, and it informs efforts to improve wound healing in humans,” said the study’s corresponding author Thomas Lozito, an assistant professor of orthopaedic surgery and stem cell biology and regenerative medicine at the Keck School of Medicine of USC.