Regulatory Mechanisms of the Germline Stem Cell Niche in Drosophila melanogaster
Stem cells possess the unique ability to produce both self-renewing and differentiating daughter cells continuously throughout an animal’s lifespan. Understanding the mechanisms that regulate proper stem cell maintenance is a central issue in basic biology and medical science. Since the stem cell niche hypothesis arose in the late 1970s, it has been widely believed that stem cells are maintained within a specialized extracellular microenvironment known as the niche. Germline stem cells (GSCs) in the fruit fly, Drosophila melanogaster, provide an excellent model for study of the stem cell niche in vivo. The first molecular components constituting the Drosophila ovarian GSC niche were identified in 1998. Since that time, identification of niche components and our understanding of how the niche maintains stem cells have continued to progress. In this review, we introduce how the niche maintains GSCs, as well as how the niche itself is precisely formed in the tissue. In addition, we discuss recent findings showing that the state of the host organism, including nutrient status and aging, affects niche function and stem cell maintenance.
KeywordsGermline stem cell Drosophila melanogaster Stem cell niche Extracellular matrix Heparan sulfate proteoglycan Glypican Aging Nutrient condition
The authors apologize to researchers whose pertinent work could not be cited due to space limitations. Research in our laboratory is supported by a Grant-in-Aid for Scientific Research (KAKENHI) on Innovative Areas (#26116730), KAKENHI for Young Scientists (A) (#25711020) to Y.H., and KAKENHI on Innovative Areas (#25114002) to S. K.