Top-DER- and Dpp-dependent requirements for the Drosophila fos/kayak gene in follicular epithelium morphogenesis.
The Drosophila fos (Dfos)/kayak gene has been previously identified as a key regulator of epithelial cell morphogenesis during dorsal closure of the embryo and fusion of the adult thorax. We show here that it is also required for two morphogenetic movements of the follicular epithelium during oogenesis. Firstly, it is necessary for the proper posteriorward migration of main body follicle cells during stage 9. Secondly, it controls, from stage 11 onwards, the morphogenetic reorganization of the follicle cells that are committed to secrete the respiratory appendages. We demonstrate that DER pathway activation and a critical level of Dpp/TGFbeta signalling are required to pattern a high level of transcription of Dfos at the anterior and dorsal edges of the two groups of cells that will give rise to the respiratory appendages. In addition, we provide evidence that, within the dorsal-anterior territory, the level of paracrine Dpp/TGFbeta signalling controls the commitment of follicle cells towards either an operculum or an appendage secretion fate. Finally, we show that Dfos is required in follicle cells for the dumping of the nurse cell cytoplasm into the oocyte and the subsequent apoptosis of nurse cells. This suggests that in somatic follicle cells, Dfos controls the expression of one or several factors that are necessary for these processes in underlying germinal nurse cells.
Dequier
E
E
Department of Developmental Biology, Institut Jacques Monod, UMR 7592, CNRS, Université Paris 7 Denis-Diderot and Université Paris 6 Pierre et Marie Curie, 2, Place Jussieu, F-75251 Cedex 05, Paris, France.
Souid
S
S
Pál
M
M
Maróy
P
P
Lepesant
J A
JA
Yanicostas
C
C
D000818:Animals; D002465:Cell Movement; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D004847:Epithelial Cells / Q000502:physiology; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology*; D009024:Morphogenesis; D009866:Oogenesis; D006080:Ovarian Follicle / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D019899:Paracrine Communication; D011494:Protein Kinases; D018010:Receptors, Invertebrate Peptide / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D016212:Transforming Growth Factor beta / Q000378:metabolism
C102117:Br protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; D018010:Receptors, Invertebrate Peptide; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; C064196:dpp protein, Drosophila; C435749:kay protein, Drosophila; D011494:Protein Kinases; C066532:Egfr protein, Drosophila; D066246:ErbB Receptors