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.
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.
Mouse Cancer Genetics Program, National Institutes of Health, National Cancer Institute at Frederick, Frederick, Maryland 21702, USA. singhshr@mail.nih.gov
Shree Ram
SR
Singh
Zhiyu
Z
Zheng
Hong
H
Wang
Su-Wan
SW
Oh
Xiu
X
Chen
Steven X
SX
Hou
D000818:Animals; D002450:Cell Communication / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism*; D018095:Germ-Line Mutation / Q000235:genetics; D053612:Janus Kinases / Q000235:genetics / Q000378:metabolism*; D008297:Male; D050791:STAT Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013091:Spermatogenesis / Q000502:physiology; D055153:Stem Cell Niche / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D029721:Drosophila Proteins; D050791:STAT Transcription Factors; C460659:Socs36E protein, Drosophila; D050826:Suppressor of Cytokine Signaling Proteins; D014157:Transcription Factors; D053612:Janus Kinases; C085845:hop protein, Drosophila