VIDEO | 1:00
In animal tissues, different cell types are able to sense cell and/or barrier damage and participate in protective responses. Among them are white blood cells that rush to injury sites to kill invading pathogens. Amazingly, these cells are able to detect the position of a wound from hundreds of micrometers away within just seconds to minutes after injury. In the thin and translucent tail fins of larval zebrafish this dramatic process can be readily followed by light microscopy.