title: Somatic cell encystment promotes abscission in germline stem cells following a regulated block in cytokinesis.
abstract: In many tissues, the stem cell niche must coordinate behavior across multiple stem cell lineages. How this is achieved is largely unknown. We have identified delayed completion of cytokinesis in germline stem cells (GSCs) as a mechanism that regulates the production of stem cell daughters in the Drosophila testis. Through live imaging, we show that a secondary F-actin ring is formed through regulation of Cofilin activity to block cytokinesis progress after contractile ring disassembly. The duration of this block is controlled by Aurora B kinase. Additionally, we have identified a requirement for somatic cell encystment of the germline in promoting GSC abscission. We suggest that this non-autonomous role promotes coordination between stem cell lineages. These findings reveal the mechanisms by which cytokinesis is inhibited and reinitiated in GSCs and why such complex regulation exists within the stem cell niche.
authors.affiliation: Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-6058, USA.
authors.forename: Kari F
authors.initials: KF
authors.lastname: Lenhart
authors.affiliation: Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-6058, USA; Institute for Regenerative Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-6058, USA. Electronic address: sdinardo@mail.med.upenn.edu.
authors.forename: Stephen
authors.initials: S
authors.lastname: DiNardo
mesh_terms: D051339:Actin Depolymerizing Factors / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D064107:Aurora Kinase B / Q000378:metabolism*; D048749:Cytokinesis / Q000502:physiology*; D004330:Drosophila; D029721:Drosophila Proteins / Q000378:metabolism*; D005854:Germ Cells / Q000166:cytology*; D054461:Lim Kinases / Q000378:metabolism; D008297:Male; D010766:Phosphorylation; D055153:Stem Cell Niche / Q000502:physiology; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000254:growth & development; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D029721:Drosophila Proteins; C576957:AurB protein, Drosophila; D064107:Aurora Kinase B; D054461:Lim Kinases; C000599872:limk1 protein, Drosophila; D054460:rho-Associated Kinases