title: Sox1 marks an activated neural stem/progenitor cell in the hippocampus.
abstract: The dentate gyrus of the hippocampus continues generating new neurons throughout life. These neurons originate from radial astrocytes within the subgranular zone (SGZ). Here, we find that Sox1, a member of the SoxB1 family of transcription factors, is expressed in a subset of radial astrocytes. Lineage tracing using Sox1-tTA;tetO-Cre;Rosa26 reporter mice shows that the Sox1-expressing cells represent an activated neural stem/progenitor population that gives rise to most if not all newly born granular neurons, as well as a small number of mature hilar astrocytes. Furthermore, a subpopulation of Sox1-marked cells have long-term neurogenic potential, producing new neurons 3 months after inactivation of tetracycline transactivator. Remarkably, after 8 weeks of labeling and a 12-week chase, as much as 44% of all granular neurons in the dentate gyrus were derived from Sox1 lineage-traced adult neural stem/progenitor cells. The fraction of Sox1-positive cells within the radial astrocyte population decreases with age, correlating with a decrease in neurogenesis. However, expression profiling shows that these cells are transcriptionally stable throughout the lifespan of the mouse. These results demonstrate that Sox1 is expressed in an activated stem/progenitor population whose numbers decrease with age while maintaining a stable molecular program.
authors.affiliation: Department of Urology, University of California, San Francisco, CA 94143,  USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Venere
authors.forename: Young-Goo
authors.initials: YG
authors.lastname: Han
authors.forename: Robert
authors.initials: R
authors.lastname: Bell
authors.forename: Jun S
authors.initials: JS
authors.lastname: Song
authors.forename: Arturo
authors.initials: A
authors.lastname: Alvarez-Buylla
authors.forename: Robert
authors.initials: R
authors.lastname: Blelloch
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D058953:Neural Stem Cells / Q000378:metabolism*; D055748:SOXB1 Transcription Factors / Q000378:metabolism*
chemical_list: D055748:SOXB1 Transcription Factors; C098693:Sox1 protein, mouse