Competitiveness for the niche and mutual dependence of the germline and somatic stem cells in the Drosophila testis are regulated by the JAK/STAT signaling

J Cell Physiol. 2010 May;223(2):500-10. doi: 10.1002/jcp.22073.


In many tissues, two or more types of stem cells share a niche, and how the stem cells coordinate their self-renewal and differentiation is poorly understood. In the Drosophila testis, germ line stem cells (GSCs) and somatic cyst progenitor cells (CPCs) contact each other and share a niche (the hub). The hub expresses a growth factor unpaired (Upd) that activates the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway in GSCs to regulate the stem cell self-renewal. Here, we demonstrate that the JAK/STAT signaling also regulates CPCs self-renewal. We also show that a negative regulator, the suppressor of cytokine signaling 36E (SOCS36E), suppresses JAK/STAT signaling in somatic cells, preventing them from out-competing the GSCs. Furthermore, through selectively manipulating the JAK/STAT signaling level in either CPCs or GSCs, we demonstrate that the somatic JAK/STAT signaling is essential for self-renewal and maintenance of both CPCs and GSCs. These data suggest that a single JAK/STAT signal from the niche orchestrate the competitive and dependent co-existence of GSCs and CPCs in the Drosophila testis niche.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Cell Communication / physiology
  • Cell Differentiation / physiology
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism*
  • Gene Expression Regulation, Developmental / physiology
  • Germ Cells / cytology
  • Germ Cells / metabolism*
  • Germ-Line Mutation / genetics
  • Janus Kinases / genetics
  • Janus Kinases / metabolism*
  • Male
  • STAT Transcription Factors / genetics
  • STAT Transcription Factors / metabolism*
  • Signal Transduction / physiology
  • Spermatogenesis / physiology
  • Stem Cell Niche / physiology*
  • Stem Cells / cytology
  • Stem Cells / metabolism*
  • Suppressor of Cytokine Signaling Proteins / genetics
  • Suppressor of Cytokine Signaling Proteins / metabolism
  • Testis / cytology
  • Testis / embryology
  • Testis / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Drosophila Proteins
  • STAT Transcription Factors
  • Socs36E protein, Drosophila
  • Suppressor of Cytokine Signaling Proteins
  • Transcription Factors
  • Janus Kinases
  • hop protein, Drosophila