title: Endoreplication controls cell fate maintenance.
abstract: Cell-fate specification is typically thought to precede and determine cell-cycle regulation during differentiation. Here we show that endoreplication, also known as endoreduplication, a specialized cell-cycle variant often associated with cell differentiation but also frequently occurring in malignant cells, plays a role in maintaining cell fate. For our study we have used Arabidopsis trichomes as a model system and have manipulated endoreplication levels via mutants of cell-cycle regulators and overexpression of cell-cycle inhibitors under a trichome-specific promoter. Strikingly, a reduction of endoreplication resulted in reduced trichome numbers and caused trichomes to lose their identity. Live observations of young Arabidopsis leaves revealed that dedifferentiating trichomes re-entered mitosis and were re-integrated into the epidermal pavement-cell layer, acquiring the typical characteristics of the surrounding epidermal cells. Conversely, when we promoted endoreplication in glabrous patterning mutants, trichome fate could be restored, demonstrating that endoreplication is an important determinant of cell identity. Our data lead to a new model of cell-fate control and tissue integrity during development by revealing a cell-fate quality control system at the tissue level.
authors.affiliation: Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, Strasbourg, France.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bramsiepe
authors.forename: Katja
authors.initials: K
authors.lastname: Wester
authors.forename: Christina
authors.initials: C
authors.lastname: Weinl
authors.forename: Farshad
authors.initials: F
authors.lastname: Roodbarkelari
authors.forename: Remmy
authors.initials: R
authors.lastname: Kasili
authors.forename: John C
authors.initials: JC
authors.lastname: Larkin
authors.forename: Martin
authors.initials: M
authors.lastname: Hülskamp
authors.forename: Arp
authors.initials: A
authors.lastname: Schnittger
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics* / Q000254:growth & development; D002453:Cell Cycle; D002454:Cell Differentiation; D004261:DNA Replication; D008855:Microscopy, Electron, Scanning; D008957:Models, Genetic; D009154:Mutation