A recent study led by HSCI Principal Faculty member Leonard Zon showed that the location of blood stem cells in the body -- their niche -- evolved to protect them against sunlight.
- What they observed: The zebrafish kidney, where its blood stem cells are located, is covered in a layer of pigmented cells called melanocytes.
- What they found: The melanocytes protected the blood stem cells from UV radiation, a component of sunlight. This was true in fish species all across the evolutionary tree of life. In a species of frog, the blood stem cells were protected from UV light throughout development thanks to the tadpole's melanocyte-covered kidney and the adult's bones.