Wingless signaling regulates the maintenance of ovarian somatic stem cells in Drosophila.
Identifying the signals involved in maintaining stem cells is critical to understanding stem cell biology and to using stem cells in future regenerative medicine. In the Drosophila ovary, Hedgehog is the only known signal for maintaining somatic stem cells (SSCs). Here we report that Wingless (Wg) signaling is also essential for SSC maintenance in the Drosophila ovary. Wg is expressed in terminal filament and cap cells, a few cells away from SSCs. Downregulation of Wg signaling in SSCs through removal of positive regulators of Wg signaling, dishevelled and armadillo, results in rapid SSC loss. Constitutive Wg signaling in SSCs through the removal of its negative regulators, Axin and shaggy, also causes SSC loss. Also, constitutive wg signaling causes over-proliferation and abnormal differentiation of somatic follicle cells. This work demonstrates that wg signaling regulates SSC maintenance and that its constitutive signaling influences follicle cell proliferation and differentiation. In mammals, constitutive beta-catenin causes over-proliferation and abnormal differentiation of skin cells, resulting in skin cancer formation. Possibly, mechanisms regulating proliferation and differentiation of epithelial cells, including epithelial stem cells, is conserved from Drosophila to man.
Song
Xiaoqing
X
Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA. tgx@stowers-institute.org
Xie
Ting
T
D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D015536:Down-Regulation; D029721:Drosophila Proteins / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009154:Mutation; D010053:Ovary / Q000166:cytology* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology*; D051155:Wnt1 Protein
D029721:Drosophila Proteins; D011518:Proto-Oncogene Proteins; D051155:Wnt1 Protein; C074622:wg protein, Drosophila