Jak-Stat pathway induces Drosophila follicle elongation by a gradient of apical contractility

Elife. 2018 Feb 8:7:e32943. doi: 10.7554/eLife.32943.


Tissue elongation and its control by spatiotemporal signals is a major developmental question. Currently, it is thought that Drosophila ovarian follicular epithelium elongation requires the planar polarization of the basal domain cytoskeleton and of the extra-cellular matrix, associated with a dynamic process of rotation around the anteroposterior axis. Here we show, by careful kinetic analysis of fat2 mutants, that neither basal planar polarization nor rotation is required during a first phase of follicle elongation. Conversely, a JAK-STAT signaling gradient from each follicle pole orients early elongation. JAK-STAT controls apical pulsatile contractions, and Myosin II activity inhibition affects both pulses and early elongation. Early elongation is associated with apical constriction at the poles and with oriented cell rearrangements, but without any visible planar cell polarization of the apical domain. Thus, a morphogen gradient can trigger tissue elongation through a control of cell pulsing and without a planar cell polarity requirement.

Keywords: D. melanogaster; developmental biology; dynamics; morphogen; morphogenesis; stem cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila / physiology*
  • Drosophila Proteins / metabolism*
  • Female
  • Janus Kinases / metabolism*
  • Morphogenesis*
  • Ovarian Follicle / growth & development*
  • STAT Transcription Factors / metabolism*
  • Signal Transduction*
  • Transcription Factors / metabolism*


  • Drosophila Proteins
  • STAT Transcription Factors
  • Transcription Factors
  • Janus Kinases
  • hop protein, Drosophila

Grants and funding

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.