October 13, 2000 - Researchers have discovered a set of regulatory cells that governs the behavior of stem cells in the fruit fly Drosophila. Stem cells retain the capability to divide and to develop into many types of adult cells. These studies suggest that the special properties of these regulatory cells allow stem cells to replenish themselves indefinitely.
In an article published in the October 13, 2000, issue of the journal Science, Howard Hughes Medical Institute investigator Allan C. Spradling and colleague Ting Xie report that they have identified the types of cells that make up the niche - a specialized cellular environment that provides stem cells with the support needed for self-renewal. Spradling and Xie characterized the niche cells that govern the production of Drosophila embryonic germline stem cells - those cells in the ovary that are the earliest precursors to eggs. According to the scientists, their findings offer a potentially valuable model to explore how stem cells are regulated in vivo.
"The idea that stem cells require niches - local environments of surrounding cells that are important for their regulation - has been around for a long time," said Spradling, who is at the Carnegie Institution of Washington. "The problem has been that mammalian stem cells have been studied by purifying them and trying to grow them in culture. So, it has been difficult to study in vivo the niches that surround the stem cells and to deduce the regulatory mechanisms that make these niches work."
According to Spradling, the niche environment may constitute a primary regulatory force that may be capable of reprogramming somatic cells to become stem cells. The Drosophila ovary represents a useful model system for studying the role of the niche in stem cell regulation, said Spradling. "Its anatomy is particularly favorable because there
Contact: Jim Keeley
Howard Hughes Medical Institute