Credit: Image: Courtesy of Dr. Otto C. Guedelhoefer, IV, University of California, Berkeley
After transplantation of healthy tissue and subsequent decapitation, planarian stem cells (shown in blue, top panel) leave the graft (shown in green, middle panel) and migrate towards the amputation site while proliferating and producing progeny (magenta). This wound-induced migration rescues the lethally irradiated host animal and eventually the stem cell compartment is completely repopulated with fully functional stem cells (shown in blue, bottom panel).