Leopard gecko

The leopard gecko is a small reptile, well known for its remarkable ability to regenerate its tail. While it cannot regrow limbs or major internal organs, the gecko's tail regeneration capability is biologically significant.

When threatened or grabbed by a predator, the leopard gecko can voluntarily detach (autotomize) its tail, a defensive strategy known as autotomy. Remarkably, it can completely regenerate the lost tail within several weeks to months. This newly grown tail restores much of the original appearance and functionality, although it often differs slightly in structure from the original, notably lacking the vertebral bones, replaced instead by a cartilage rod.

Tail regeneration in leopard geckos involves a clear and structured biological response. Immediately after tail loss, a wound epithelium quickly forms to cover and protect the exposed tissue. Beneath this protective layer, cells at the injury site begin rapid proliferation, forming a regenerative structure called a blastema. This blastema, composed of various proliferating progenitor cells, gradually differentiates into the multiple tissues required for a complete tail, including cartilage, muscle, skin, blood vessels, and nerves.

Beyond tail regeneration, leopard geckos have shown other regenerative abilities that make them even more fascinating as research models. Notably, they can regenerate skin without forming scars, and even show the capacity to regenerate neurons within the brain. This scarless regeneration in particular has attracted attention from scientists aiming to understand how vertebrates manage tissue repair without fibrosis, a major challenge in human wound healing.

An important area of current research involves understanding how regeneration is affected by age. Leopard geckos are relatively long-lived reptiles, capable of reaching up to 28 years of age. This longevity provides a unique opportunity to study how regeneration changes across the lifespan, an area that remains largely unexplored. In mammals, aging often leads to increased scarring and reduced regenerative capacity, linked with an increase in fibrosis. Whether older leopard geckos retain their remarkable ability to regenerate scar-free skin and other tissues, similar to younger geckos, remains an open and intriguing question. Answering this could help scientists discover fundamental biological processes that prevent fibrosis and preserve regenerative abilities across age, which would have significant implications for human medicine.

The leopard gecko genome has recently been sequenced and assembled, further enhancing its utility as a model organism. With a fully characterized genome, it becomes possible to explore regeneration at the genetic and molecular levels. Researchers can now identify specific genes involved in regenerative responses, compare them across different ages, and understand how their activity changes during the aging process.