Coordinated niche-associated signals promote germline homeostasis in the Drosophila ovary.
Stem cell niches provide localized signaling molecules to promote stem cell fate and to suppress differentiation. The Drosophila melanogaster ovarian niche is established by several types of stromal cells, including terminal filament cells, cap cells, and escort cells (ECs). Here, we show that, in addition to its well-known function as a niche factor expressed in cap cells, the Drosophila transforming growth factor β molecule Decapentaplegic (Dpp) is expressed at a low level in ECs to maintain a pool of partially differentiated germline cells that may dedifferentiate to replenish germline stem cells upon their depletion under normal and stress conditions. Our study further reveals that the Dpp level in ECs is modulated by Hedgehog (Hh) ligands, which originate from both cap cells and ECs. We also demonstrate that Hh signaling exerts its function by suppressing Janus kinase/signal transducer activity, which promotes Dpp expression in ECs. Collectively, our data suggest a complex interplay of niche-associated signals that controls the development of a stem cell lineage.
Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604.
Zhong
Z
Liu
Laboratory of Insect Toxicology, South China Agriculture University, Guangzhou, PR China 510642.
Guohua
G
Zhong
Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604.
Phing Chian
PC
Chai
Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117543.
Lichao
L
Luo
Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604.
Sen
S
Liu
Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117543.
Ying
Y
Yang
Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597.
Gyeong-Hun
GH
Baeg
Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117543 caiyu@tll.org.sg.
Yu
Y
Cai
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000254:growth & development*; D005260:Female; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D006706:Homeostasis; D053612:Janus Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D010053:Ovary / Q000166:cytology / Q000254:growth & development*; D034622:RNA Interference; D034741:RNA, Small Interfering; D050791:STAT Transcription Factors / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D055153:Stem Cell Niche / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology*; D014157:Transcription Factors / Q000235:genetics
C093752:Bric-a-brac protein 1, Drosophila; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C557617:GAL4 protein, Drosophila; D053823:Hedgehog Proteins; D034741:RNA, Small Interfering; D050791:STAT Transcription Factors; D014157:Transcription Factors; C064196:dpp protein, Drosophila; C077245:hh protein, Drosophila; D053612:Janus Kinases