Regeneration: Lessons from the Lizard

Abstract

While regeneration of appendages is observed in a number of vertebrates, including teleost fish, amphibians, and squamate reptiles, birds and mammals, including humans, have very limited capacity. The combination of cellular and tissue-based studies together with high throughput sequencing technologies now permit investigations into the molecular mechanisms underlying regeneration of appendages in vertebrates. As the first squamate reptile with a fully sequenced and annotated genome, the green anole lizard, Anolis carolinensis, has yielded insights into both the cellular and molecular programs for regeneration. RNA-Seq based studies have identified both developmental and repair mechanisms in anole tail regeneration, particularly pathways regulating formation of the wound epithelium, modulation of the immune response, musculoskeletal development, remodeling of the extracellular matrix, and activation of Wnt/β-catenin and FGF signaling pathways. Additionally, both conserved and novel microRNAs have been identified in tail regeneration in the anole, giving insights into upstream regulators of the regenerative process. Ongoing comparative studies of lizard regeneration could potentially be translated into future regenerative therapeutics for appendage biological prosthetics.