Philip Ball in Aeon:
In one of the most dramatic demonstrations to date that cells are capable of more than we had imagined, the biologist Michael Levin of Tufts University in Medford, Massachusetts and his colleagues have shown that frog cells liberated from their normal developmental path can organise themselves in distinctly un-froglike ways. The researchers separated cells from frog embryos that were developing into skin cells, and simply watched what the free cells did.
Culturing cells – growing them in a dish where they are fed the nutrients they need – is a mature technology. In general, such cells will form an expanding colony as they divide. But the frog skin cells had other plans. They clustered into roughly spherical clumps of up to several thousand cells each, and the surface cells developed little hairlike protrusions called cilia (also present on normal frog skin). The cilia waved in coordinated fashion to propel the clusters through the solution, much like rowing oars. These cell clumps behaved like tiny organisms in their own right, surviving for a week or more – sometimes several months – if supplied with food. The researchers called them xenobots, derived from Xenopus laevis, the Latin name of the African clawed frog from which the cells were taken.