Study
Cells keep a memory of their tissue origin during axolotl limb regeneration
Kragl, Martin; Knapp, Dunja; Nacu, Eugeniu; Khattak, Shahryar; Maden, Malcolm; Epperlein, Hans-Henning; Tanaka, Elly M.
Nature, 2009
Tissues from axolotls engineered to express green fluorescent protein were grafted into ordinary animals, so that every descendant of a known starting tissue could be followed by its glow. The limb was then amputated and the origin of the cells building each tissue of the regenerate traced directly.
- Studied in
- Ambystoma mexicanum
- Sample size
- grafted transgenic tissue tracked through regeneration
Blastema cells overwhelmingly rebuilt the tissue type they came from: grafted muscle produced muscle, cartilage produced cartilage, and so on. The blastema is not a pool of pluripotent stem cells but a mixed population of lineage-restricted progenitors. Dermal and cartilage lineages showed some interchange; muscle did not.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Limb regeneration proceeds through partial dedifferentiation into lineage-restricted progenitors that remember their origin, rather than through reversion to a pluripotent state.
How NatureHQ reads it
This overturns the intuitive picture and is the single most useful fact for a reader who wants to know why humans cannot do it. The obvious guess is that the axolotl turns cells back into something embryonic and starts again. It does not. Cells relax their identity just enough to divide and move, and each one keeps knowing what it is. That makes regeneration a coordination problem rather than a stem-cell problem, which is a much harder thing to borrow — the missing ingredient is not a cell type we lack but an instruction system we do not run.
- Grafting itself is a perturbation and may influence lineage behaviour.
- Small proportions of cells crossing lineage boundaries are hard to exclude at these sample sizes.
- One species; the extent to which this generalises to other regenerating animals is not established here.
Following individual cells through a regrowing limb
When an axolotl regrows a limb, does it turn cells back into stem cells and start over?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Nature PortfolioPublished in a Nature Portfolio journal.
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NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-11.