title: The ecdysone receptor signalling regulates microvilli formation in follicular epithelial cells.
abstract: Epithelial morphogenesis contributes greatly to the development and homeostasis of the organs and body parts. Here, we analysed the consequences of impaired ecdysone receptor (EcR) signalling in the Drosophila follicular epithelium. Besides governing cell growth, the three EcR isoforms act redundantly in controlling follicle cell positioning. Flattening of the microvilli and an aberrant actin cytoskeleton arise from defective EcR signalling in follicle cells, and these defects impact on the organisation of the oocyte membrane. We found that this signalling governs a complex molecular network since its impairment affects key molecules as atypical protein kinase C and activated Moesin. Interestingly, the activity of the transcription factor Tramtrack69 isoform is required for microvilli and their actin core morphogenesis as well as for follicle cell positioning. In conclusion, our findings provide evidence of novel roles for EcR signalling and Tramtrack69 transcription factor in controlling stage-specific differentiation events that take place in the follicular epithelium.
authors.affiliation: Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, Via Selmi, 3, 40126, Bologna, Italy. patrizia.romani@unibo.it.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Romani
authors.affiliation: Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, Via Selmi, 3, 40126, Bologna, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gargiulo
authors.affiliation: Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, Via Selmi, 3, 40126, Bologna, Italy. valeria.cavaliere@unibo.it.
authors.forename: Valeria
authors.initials: V
authors.lastname: Cavaliere
mesh_terms: D000818:Animals; D004330:Drosophila / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000378:metabolism*; D005260:Female; D008871:Microvilli / Q000378:metabolism* / Q000648:ultrastructure; D009865:Oocytes / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D009866:Oogenesis; D006080:Ovarian Follicle / Q000166:cytology* / Q000254:growth & development* / Q000648:ultrastructure; D011987:Receptors, Steroid / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029721:Drosophila Proteins; D011987:Receptors, Steroid; D012097:Repressor Proteins; C055469:ecdysone receptor; C075878:ttk protein, Drosophila
keywords: Cad99C; EcR dominant negative; Ecdysone signalling; Oogenesis