Nine cell types to re-grow a fin
Understanding regeneration in model organisms gives hope that it may one day be possible for amputees to regrow limbs, or for heart attack patients to regrow healthy heart muscle.
If zebrafish lose a fin a special group of cells form on the stump. These cells regrow the new fin and it was assumed they were stem cells. Now a recent study has shown that the group of cells that form on the stump are actually composed of nine different cell types and, as the new fin develops, each cell-type gives rise to more cells of the same type. So skin cells give rise to more skin cells and nerve cells give rise to more nerve cells and so on.
There was no evidence of one type of cell transforming into another. In fact, different cell-types that are already present on the stump work together to re-grow a limb – in this case a fin. This suggests a different and more complex strategy will be required to initiate and manage limb regeneration in other organisms. Simply adding generalised stem cells will not be sufficient.