Regeneration of fins and limbs relies on a shared cellular playbook Skip to content Subscribe today Every print subscription comes with full digital access Subscribe Now Menu All Topics Health Humans Anthropology Health & Medicine Archaeology Psychology View All Life Animals Plants Ecosystems Paleontology Neuroscience Genetics Microbes View All Earth Agriculture Climate Oceans Environment View All Physics Materials Science Quantum Physics Particle Physics View All Space Astronomy Planetary Science Cosmology View All Magazine Menu All Stories Multimedia Reviews Puzzles Collections Educator Portal Century of Science Unsung characters Coronavirus Outbreak Newsletters Investors Lab About SN Explores Our Store SIGN IN Donate Home INDEPENDENT JOURNALISM SINCE 1921 SIGN IN Search Open search Close search Home INDEPENDENT JOURNALISM SINCE 1921 All Topics Earth Agriculture Climate Oceans Environment Humans Anthropology Health & Medicine Archaeology Psychology Life Animals Plants Ecosystems Paleontology Neuroscience Genetics Microbes Physics Materials Science Quantum Physics Particle Physics Space Astronomy Planetary Science Cosmology Tech Computing Artificial Intelligence Chemistry Math Science & Society All Topics Health Humans Humans Anthropology Health & Medicine Archaeology Psychology Recent posts in Humans Artificial Intelligence Real-world medical questions stump AI chatbots By Tina Hesman SaeyFebruary 17, 2026 Health & Medicine A simple shift in schedule could make cancer immunotherapy work better By Elie DolginFebruary 12, 2026 Health & Medicine This baby sling turns sunlight into treatment for newborn jaundice By Elie DolginFebruary 12, 2026 Life Life Animals Plants Ecosystems Paleontology Neuroscience Genetics Microbes Recent posts in Life Animals Some dog breeds carry a higher risk of breathing problems By Jake Buehler2 hours ago Animals Regeneration of fins and limbs relies on a shared cellular playbook By Elizabeth Pennisi4 hours ago Animals How tracking golden eagles in Nevada revealed a desert ‘death vortex’ By Martin J. 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It also can regrow entire fins, making it a good case study for understanding the origins of limb regeneration. blickwinkel/Alamy By Elizabeth Pennisi 4 hours ago Share this:Share Share via email (Opens in new window) Email Share on Facebook (Opens in new window) Facebook Share on Reddit (Opens in new window) Reddit Share on X (Opens in new window) X Print (Opens in new window) Print In the 2012 movie The Amazing Spider-Man, a key character regrows his missing arm by imbibing reptilian DNA — but then turns into a monster lizard that Spider-Man must foil. While humans outside the Marvel Cinematic Universe can’t regrow limbs, a new study has uncovered a shared genetic and cellular toolkit for regenerating appendages in fish and salamanders. The work, reported January 22 in Nature Communications, reveals clues about how far back in evolutionary time regeneration appeared in vertebrates. Interested in how vertebrates evolved — and often lost — the ability to regrow body parts, evolutionary developmental biologist Igor Schneider of Louisiana State University in Baton Rouge has focused on understanding regeneration in the Senegal bichir (Polypterus senegalus). This fish can regrow an entire lost fin. And because it sits at the base of the family tree of modern bony fish, the bichir is considered a living fossil. Sign up for our newsletter We summarize the week's scientific breakthroughs every Thursday. Studying this fish “helps fill a big gap in the story of how regeneration evolved,” says developmental biologist Ji-Feng Fei of the Guangdong Academy of Medical Sciences in Guangzhou, China, who was not involved with the work. For the new study, Schneider’s team cut fins off bichirs and tracked gene activity at the wound site after one, three and seven days, which revealed the types of cells present and their activity. The team compared those data to similar new and existing data about the axolotl, a salamander that regrows limbs, and the zebrafish, a modern bony fish that can regrow the bony tips of its fins. In all three species, the team found that immune cells rushed to the scene. There, they first fended off bacteria, a typical response to wounding found even in humans. But in the bichir and axolotl, the immune system quickly switched tactics, dampening any further inflammatory response that would otherwise cause scar tissue to form. Typically, blood supply — and consequently oxygen flow — is disrupted in wounds. The new data clarified how these three animals compensated: Many types of cells in the wound began producing energy using a chemical pathway that did not require oxygen. This energy fueled the production of more cells and of proteins and other materials needed for regeneration. In the two fish species, myoglobin, which muscles depend on for oxygen storage, appeared in skin cells covering the wounds. Unexpectedly, red blood cells also rushed to the amputation site in the bichir and axolotl, eventually making up to 20 percent of all the cells at the wound site. Typically, red blood cells represent less than 2 percent of the cells in that part of a fin or limb. “The red blood cell thing blew my mind,” Fei says. In humans, red blood cells lose their nuclei as they mature, but in both the bichir and axolotl these cells retain nuclei. Inside these nuclei, genes for controlling immune responses and for monitoring oxyg
Regeneration of fins and limbs relies on a shared cellular playbook
