title: Specification of differentiated adult progenitors via inhibition of endocycle entry in the Drosophila trachea.
abstract: A population of Drosophila adult tracheal progenitor cells arises from differentiated cells of the larval main trachea that retain the ability to reenter the cell cycle and give rise to the multiple adult tracheal cell types. These progenitors are unique to the second tracheal metamere as homologous cells from other segments, express fizzy-related (fzr), the Drosophila homolog of CDH1 protein of the APC complex, and enter endocycle and do not contribute to adult trachea. Here, we examine the mechanisms for their quiescence and show that they reenter the cell cycle by expression of string/cdc25 through ecdysone. Furthermore, we show that preventing endocycle entry is both necessary and sufficient for these tracheal cells to exhibit markers of adult progenitors, thus modifying their genetic program. Finally, we show that Hox-mediated regulation of fzr expression is responsible for progenitor identity and thus specifies a group of differentiated cells with facultative stem cell features.
authors.affiliation: Institut de Biología Molecular de Barcelona (CSIC), Carrer de Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain; Institut de Recerca Biomèdica de Barcelona, Carrer de Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain.
authors.forename: Nareg J-V
authors.initials: NJ
authors.lastname: Djabrayan
authors.affiliation: Institut de Biologia Evolutiva (CSIC-UPF), Platja de la Barceloneta 37, 08003 Barcelona, Catalonia, Spain.
authors.forename: Josefa
authors.initials: J
authors.lastname: Cruz
authors.affiliation: Institut de Biología Molecular de Barcelona (CSIC), Carrer de Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain; Institut de Biologia Evolutiva (CSIC-UPF), Platja de la Barceloneta 37, 08003 Barcelona, Catalonia, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: de Miguel
authors.affiliation: Institut de Biologia Evolutiva (CSIC-UPF), Platja de la Barceloneta 37, 08003 Barcelona, Catalonia, Spain. Electronic address: xavier.franch@ibe.upf-csic.es.
authors.forename: Xavier
authors.initials: X
authors.lastname: Franch-Marro
authors.affiliation: Institut de Biología Molecular de Barcelona (CSIC), Carrer de Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain; Institut de Recerca Biomèdica de Barcelona, Carrer de Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain. Electronic address: jcrbmc@ibmb.csic.es.
authors.forename: Jordi
authors.initials: J
authors.lastname: Casanova
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology*; D005260:Female; D008297:Male; D014132:Trachea / Q000166:cytology*
chemical_list: D029721:Drosophila Proteins