Poison frogs help solve a stem cell mystery!

Our poison frogs help solve an evolutionary mystery about where stem cells are made. In all mammals, stem cells and blood are made in bones - by why is that? This study showed that all aquatic animals have a melanocyte umbrella above their stem cell niche. Our frogs came into the story with first author Friedrich called Lauren up (when she was a Bauer Fellow at Harvard) to ask for some frog samples. Friedrich was interested in what happened to the stem cell niche during amphibian metamorphosis. They first looked at Xenopus, but those frogs are aquatic and never move their stem cell niche into their bones. Enter hero Dendrobates tinctorius - we used a developmental series of D. tinctorius tadpoles to show that the location of where the frogs make stem cells moves from the kidney to the bones as the frogs move from water to land during metamorphosis. This fit with a hypothesis that land animals make stem cells in their bones to protect fro UV-damage. Thus the poison frogs taught us a little bit about ourselves - and why we make stem cells in our bones.