“I-cells in the cnidarian Hydractinia and their role in development and regeneration
Hydractinia is a cnidarian (a close relative of jellyfish, sea anemones and corals) that has an unusual ability to regenerate. This is based on a population of stem cells, called i-cells, that are similar to our own embryonic cells in their plasticity, but in Hydractinia they are maintained throughout adult life. Hence, the adult animal retains embryonic-like features that enable it to replace any lost body part. Hydractinia outperforms humans in its regenerative ability, and understanding how it does so could explain why we do not perform that well and provide out-of-the-box ideas to improve human tissue renewal following injury or disease.