Abstract

Crustacean limb regeneration relies on committed progenitor cells, including satellite-like muscle precursors. Many animals are able to regenerate amputated or damaged body parts, but it is unclear whether different taxa rely on similar strategies. Planarians and vertebrates use different strategies, based on pluripotent versus committed progenitor cells, respectively, to replace missing tissues. In most animals, however, we lack the experimental tools needed to determine the origin of regenerated tissues. Here, we present a genetically tractable model for limb regeneration, the crustacean Parhyale hawaiensis. We demonstrate that regeneration in Parhyale involves lineage-committed progenitors, as in vertebrates. We discover Pax3/7-expressing muscle satellite cells, previously identified only in chordates, and show that these cells are a source of regenerating muscle in Parhyale. These similarities point to a common cellular basis of regeneration, dating back to the common ancestors of bilaterians. Limb Regeneration Flatworms possess pluripotent stem cells that can regenerate any cell type in the body, whereas vertebrates mobilize committed progenitor cells whose fate is predetermined. Investigating limb regeneration in a crustacean, Konstantinides and Averof (p. 788, published online 2 January) found that arthropods use committed progenitor cells to regenerate missing tissues, including satellite-like cells to regenerate muscle. The study reveals similarities between arthropod and vertebrate muscle regeneration, pointing to a common basis for muscle regeneration that may date back to the common ancestors of all bilaterian animals.