USC faculty member Krzysztof Kobielak and his team used a system to make all of the sweat gland cells in a mouse easy to spot: labeling them with green fluorescent protein (GFP), which is visible under ultraviolet light.
Over time, the GFP became dimmer as it was diluted among dividing sweat gland cells. After four weeks, the only cells that remained fluorescent were the ones that did not divide or divided very slowly - a known property among stem cells of certain tissues, including the hair follicle and cornea.
Therefore, these slow-dividing, fluorescent cells in the sweat gland's coiled lower region were likely also stem cells.
Then, the first author of this paper, graduate student Yvonne Leung, tested whether these fluorescent cells could do what stem cells do best - differentiate into multiple cell types.
To the researchers' surprise, these glowing cells generated not only sweat glands, but also hair follicles when placed in the skin of a mouse without GFP.
The study has been published in journal Public Library of Science One (PLOS ONE).