title: FGF signaling supports Drosophila fertility by regulating development of ovarian muscle tissues.
abstract: The thisbe (ths) gene encodes a Drosophila fibroblast growth factor (FGF), and mutant females are viable but sterile suggesting a link between FGF signaling and fertility. Ovaries exhibit abnormal morphology including lack of epithelial sheaths and muscle tissues that surround ovarioles. Here we investigated how FGF influences Drosophila ovary morphogenesis and identified several roles. Heartless (Htl) FGF receptor was found to be expressed within somatic cells at the larval and pupal stages, and phenotypes were uncovered using RNAi. Differentiation of terminal filament cells was affected, but this effect did not alter the ovariole number. In addition, proliferation of epithelial sheath progenitors, the apical cells, was decreased in both htl and ths mutants, while ectopic expression of the Ths ligand led to these cells' over-proliferation suggesting that FGF signaling supports ovarian muscle sheath formation by controlling apical cell number in the developing gonad. Additionally, live imaging of adult ovaries was used to show that htl RNAi mutants, hypomorphic mutants in which epithelial sheaths are present, exhibit abnormal muscle contractions. Collectively, our results demonstrate that proper formation of ovarian muscle tissues is regulated by FGF signaling in the larval and pupal stages through control of apical cell proliferation and is required to support fertility.
authors.affiliation: Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States.
authors.forename: Jihyun
authors.initials: J
authors.lastname: Irizarry
authors.affiliation: Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States. Electronic address: angelike@caltech.edu.
authors.forename: Angelike
authors.initials: A
authors.lastname: Stathopoulos
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000254:growth & development* / Q000378:metabolism; D005260:Female; D005298:Fertility; D005346:Fibroblast Growth Factors / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D038081:Organogenesis; D010053:Ovary / Q000254:growth & development / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029721:Drosophila Proteins; D017468:Receptors, Fibroblast Growth Factor; C543523:ths protein, Drosophila; D005346:Fibroblast Growth Factors; D011505:Protein-Tyrosine Kinases; C102667:htl protein, Drosophila
keywords: Apical cells; Drosophila; Epithelial sheath; FGF signaling; Fertility; Heartless; Muscles; Ovary morphogenesis; Proliferation; Pyramus; Thisbe