title: Centrosome misorientation mediates slowing of the cell cycle under limited nutrient conditions in Drosophila male germline stem cells.
abstract: Drosophila male germline stem cells (GSCs) divide asymmetrically, balancing self-renewal and differentiation. Although asymmetric stem cell division balances between self-renewal and differentiation, it does not dictate how frequently differentiating cells must be produced. In male GSCs, asymmetric GSC division is achieved by stereotyped positioning of the centrosome with respect to the stem cell niche. Recently we showed that the centrosome orientation checkpoint monitors the correct centrosome orientation to ensure an asymmetric outcome of the GSC division. When GSC centrosomes are not correctly oriented with respect to the niche, GSC cell cycle is arrested/delayed until the correct centrosome orientation is reacquired. Here we show that induction of centrosome misorientation upon culture in poor nutrient conditions mediates slowing of GSC cell proliferation via activation of the centrosome orientation checkpoint. Consistently, inactivation of the centrosome orientation checkpoint leads to lack of cell cycle slowdown even under poor nutrient conditions. We propose that centrosome misorientation serves as a mediator that transduces nutrient information into stem cell proliferation, providing a previously unappreciated mechanism of stem cell regulation in response to nutrient conditions.
authors.affiliation: Life Sciences Institute, Center for Stem Cell Biology, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Therese M
authors.initials: TM
authors.lastname: Roth
authors.forename: C-Y Ason
authors.initials: CY
authors.lastname: Chiang
authors.forename: Mayu
authors.initials: M
authors.lastname: Inaba
authors.forename: Hebao
authors.initials: H
authors.lastname: Yuan
authors.forename: Viktoria
authors.initials: V
authors.lastname: Salzmann
authors.forename: Caitlin E
authors.initials: CE
authors.lastname: Roth
authors.forename: Yukiko M
authors.initials: YM
authors.lastname: Yamashita
mesh_terms: D000818:Animals; D060049:Asymmetric Cell Division / Q000502:physiology*; D002453:Cell Cycle; D002455:Cell Division; D018385:Centrosome / Q000502:physiology*; D004330:Drosophila / Q000166:cytology* / Q000502:physiology; D029721:Drosophila Proteins / Q000378:metabolism / Q000502:physiology; D005854:Germ Cells / Q000166:cytology / Q000502:physiology*; D008297:Male; D009752:Nutritional Status; D008941:Spindle Apparatus / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D025521:Tumor Suppressor Proteins / Q000502:physiology
chemical_list: C467323:APC2 protein, Drosophila; D029721:Drosophila Proteins; D025521:Tumor Suppressor Proteins