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

• Published in: Journal of cellular physiology 2010-05, Vol.223 (2), p.500-510
• Main Authors: Singh, Shree Ram, Zheng, Zhiyu, Wang, Hong, Oh, Su-Wan, Chen, Xiu, Hou, Steven X.
• Format: Article
• Language: English
• Subjects: Animals; Cell Communication - physiology; Cell Differentiation - physiology; Drosophila melanogaster - embryology; Drosophila melanogaster - genetics; Drosophila melanogaster - metabolism; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Gene Expression Regulation, Developmental - physiology; Germ Cells - cytology; Germ Cells - metabolism; Germ-Line Mutation - genetics; Janus Kinases - genetics; Janus Kinases - metabolism; Male; Signal Transduction - physiology; Spermatogenesis - physiology; STAT Transcription Factors - genetics; STAT Transcription Factors - metabolism; 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
• ISSN: 0021-9541; 1097-4652
• 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. J. Cell. Physiol. 223: 500–510, 2010. © 2010 Wiley‐Liss, Inc.