title: Conversion of quiescent niche cells to somatic stem cells causes ectopic niche formation in the Drosophila testis.
abstract: Adult stem cells reside in specialized regulatory microenvironments, or niches, where local signals ensure stem cell maintenance. The Drosophila testis contains a well-characterized niche wherein signals from postmitotic hub cells promote maintenance of adjacent germline stem cells and somatic cyst stem cells (CySCs). Hub cells were considered to be terminally differentiated; here, we show that they can give rise to CySCs. Genetic ablation of CySCs triggers hub cells to transiently exit quiescence, delaminate from the hub, and convert into functional CySCs. Ectopic Cyclin D-Cdk4 expression in hub cells is also sufficient to trigger their conversion into CySCs. In both cases, this conversion causes the formation of multiple ectopic niches over time. Therefore, our work provides a model for understanding how oncogenic mutations in quiescent niche cells could promote loss of quiescence, changes in cell fate, and aberrant niche expansion.
authors.affiliation: Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
authors.forename: Phylis
authors.initials: P
authors.lastname: Hétié
authors.affiliation: Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
authors.forename: Margaret
authors.initials: M
authors.lastname: de Cuevas
authors.affiliation: Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA. Electronic address: matunis@jhmi.edu.
authors.forename: Erika
authors.initials: E
authors.lastname: Matunis
mesh_terms: D000818:Animals; D056741:Cyclin D / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins / Q000378:metabolism; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism; D008297:Male; D055153:Stem Cell Niche; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013737:Testis / Q000166:cytology*
chemical_list: D056741:Cyclin D; D029721:Drosophila Proteins; C495896:Cdk4 protein, Drosophila; D051358:Cyclin-Dependent Kinase 4
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