A gradient of JAK pathway activity patterns the anterior-posterior axis of the follicular epithelium

Dev Cell. 2003 Feb;4(2):167-77. doi: 10.1016/s1534-5807(02)00412-4.


The Drosophila egg develops through closely coordinated activities of associated germline and somatic cells. An essential aspect of egg development is the differentiation of the somatic follicle cells into several distinct subpopulations with specific functions. Here we demonstrate that the graded activity of the Janus kinase (JAK) pathway, stimulated by the Unpaired ligand, patterns the anterior-posterior axis of the follicular epithelium. Different levels of JAK activity instruct adoption of distinct anterior cell fates. Further, the coordinated activities of the JAK/STAT and epidermal growth factor receptor (EGFR) pathways are required to specify the posterior terminal cell fate. We propose that Upd secreted from the polar cells may act as a morphogen to stimulate A/P-derived follicular fates through JAK pathway activation.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Cell Differentiation
  • Cell Polarity
  • DNA-Binding Proteins / metabolism
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / embryology*
  • Drosophila melanogaster / genetics
  • Embryo, Nonmammalian / physiology*
  • Enzyme Activation
  • Epithelial Cells / cytology*
  • ErbB Receptors / metabolism
  • Female
  • Gene Expression Regulation, Developmental
  • Glycoproteins / metabolism
  • Janus Kinase 1
  • Mutation
  • Oogenesis / physiology*
  • Ovarian Follicle / cytology
  • Ovarian Follicle / physiology*
  • Phenotype
  • Protein-Tyrosine Kinases / metabolism*
  • STAT3 Transcription Factor
  • Signal Transduction / physiology*
  • Trans-Activators / metabolism
  • Transcription Factors*


  • DNA-Binding Proteins
  • Drosophila Proteins
  • Glycoproteins
  • STAT3 Transcription Factor
  • Trans-Activators
  • Transcription Factors
  • upd1 protein, Drosophila
  • ErbB Receptors
  • Protein-Tyrosine Kinases
  • Janus Kinase 1