title: Polycomb controls gliogenesis by regulating the transient expression of the Gcm/Glide fate determinant.
abstract: The Gcm/Glide transcription factor is transiently expressed and required in the Drosophila nervous system. Threshold Gcm/Glide levels control the glial versus neuronal fate choice, and its perdurance triggers excessive gliogenesis, showing that its tight and dynamic regulation ensures the proper balance between neurons and glia. Here, we present a genetic screen for potential gcm/glide interactors and identify genes encoding chromatin factors of the Trithorax and of the Polycomb groups. These proteins maintain the heritable epigenetic state, among others, of HOX genes throughout development, but their regulatory role on transiently expressed genes remains elusive. Here we show that Polycomb negatively affects Gcm/Glide autoregulation, a positive feedback loop that allows timely accumulation of Gcm/Glide threshold levels. Such temporal fine-tuning of gene expression tightly controls gliogenesis. This work performed at the levels of individual cells reveals an undescribed mode of Polycomb action in the modulation of transiently expressed fate determinants and hence in the acquisition of specific cell identity in the nervous system.
authors.affiliation: Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UDS, Illkirch, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Popkova
authors.forename: Roberto
authors.initials: R
authors.lastname: Bernardoni
authors.forename: Celine
authors.initials: C
authors.lastname: Diebold
authors.forename: Véronique
authors.initials: V
authors.lastname: Van de Bor
authors.forename: Bernd
authors.initials: B
authors.lastname: Schuettengruber
authors.forename: Inma
authors.initials: I
authors.lastname: González
authors.forename: Ana
authors.initials: A
authors.lastname: Busturia
authors.forename: Giacomo
authors.initials: G
authors.lastname: Cavalli
authors.forename: Angela
authors.initials: A
authors.lastname: Giangrande
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage / Q000235:genetics; D002843:Chromatin / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D009420:Nervous System / Q000254:growth & development / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics*; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D063150:Polycomb Repressive Complex 1 / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C102805:GCM protein, Drosophila; C066770:Pc protein, Drosophila; D014157:Transcription Factors; C512571:trx protein, Drosophila; D063150:Polycomb Repressive Complex 1