title: Stem cell self-renewal specified by JAK-STAT activation in response to a support cell cue.
abstract: Stem cells generate many differentiated, short-lived cell types, such as blood, skin, and sperm, throughout adult life. Stem cells maintain a long-term capacity to divide, producing daughter cells that either self-renew or initiate differentiation. Although the surrounding microenvironment or "niche" influences stem cell fate decisions, few signals that emanate from the niche to specify stem cell self-renewal have been identified. Here we demonstrate that the apical hub cells in the Drosophila testis act as a cellular niche that supports stem cell self-renewal. Hub cells express the ligand Unpaired (Upd), which activates the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway in adjacent germ cells to specify self-renewal and continual maintenance of the germ line stem cell population.
authors.affiliation: Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Kiger
authors.forename: D L
authors.initials: DL
authors.lastname: Jones
authors.forename: C
authors.initials: C
authors.lastname: Schulz
authors.forename: M B
authors.initials: MB
authors.lastname: Rogers
authors.forename: M T
authors.initials: MT
authors.lastname: Fuller
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D019070:Cell Lineage; D003463:Cues; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins / Q000378:metabolism*; D005854:Germ Cells / Q000502:physiology*; D006023:Glycoproteins / Q000378:metabolism*; D053612:Janus Kinases; D008024:Ligands; D008297:Male; D009154:Mutation; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D050791:STAT Transcription Factors; D015398:Signal Transduction; D013090:Spermatocytes / Q000166:cytology / Q000502:physiology; D013091:Spermatogenesis; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D013737:Testis / Q000166:cytology / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006023:Glycoproteins; D008024:Ligands; D050791:STAT Transcription Factors; C105675:Stat92E protein, Drosophila; D015534:Trans-Activators; D014157:Transcription Factors; C115570:upd1 protein, Drosophila; D011505:Protein-Tyrosine Kinases; D053612:Janus Kinases; C085845:hop protein, Drosophila