University of Texas (UT) Southwestern Medical Center scientists collaborating with University of Michigan researchers have found a previously unidentified mechanism that helps explain why stem cells undergo self-renewing divisions but their offspring do not. Adult stem cells provide a ready supply of new cells needed for tissue homeostasis throughout the life of an organism. Specialized environments called “niches” help to maintain stem cells in an undifferentiated and self-renewing state. Cells that comprise the niche produce signals and growth factors essential for stem cell maintenance. The mechanisms that allow for reception of these signals exclusively by stem cells and not their more specialized progeny remain poorly understood. “This finding stands to change the way we think about how stem cells and their neighbors communicate with one another,” said Dr. Michael Buszczak (at right in photo), Associate Professor in the Department of Molecular Biology and with the Hamon Center for Regenerative Science and Medicine at UT Southwestern. The findings were published online on July 1, 2015 in Nature. The article is titled “Nanotubes Mediate Niche–Stem-Cell Signalling in the Drosophila Testis.” Scientists have been working to understand how the signaling between niches and stem cells works. “These signals act over a short range, so only stem cells − but not their differentiating progeny − receive the self-renewing signals,” said Dr. Buszczak, E.E. and Greer Garson Fogelson Scholar in Medical Research. “The mechanics of this communication were not known. What we discovered was that the stem cells form microtubule-based nanotubes, which extend into the niche.Login Or Register To Read Full Story