Figure 4.

In vivo migration of stem cells in planarians. (a) Neoblasts labeled with the stem cell marker Smed-piwi-1 (purple) in a partially irradiated, unamputated (intact) animal. (b) Migrating neoblasts in a decapitated, partially irradiated animal. Arrow points to neoblasts at or near the site of amputation. (c) A decapitated, partially irradiated animal in which cells are visualized via fluorescent in situ hybridization. Neoblasts are in green (Smed-piwi-1) and post-mitotic progeny in magenta (Prog-1). (a,b) Arrowheads denote the boundary between irradiated (top) and unirradiated (bottom) tissues. Modified from [22].