Figure 3. Ependymal Cells Display Neural Stem Cell Properties In Vitro.

(A) Schematic depiction of tamoxifen administration paradigm and (B) analysis of neural stem cell properties and in vivo and in vitro recombination frequency.

(C) The high proportion of recombined (rec.) neurospheres (mean + SD, n = 6 mice for each transgenic mouse line) demonstrates that the majority derives from ependymal cells.

(D) Estimate of the proportion of neurospheres that derive from ependymal cells by normalization to the recombination rate in tissue sections of the spinal cords that were used to initiate the cultures (mean ± SD).

(E) Recombined primary neurospheres from FoxJ1-CreER mice on R26R background visualized by X-gal staining (arrow points to one unrecombined neurosphere).

(F) Differentiation of a clonally derived recombined neurosphere into neurons (βIIItub), astrocytes (GFAP), and oligodendrocytes (O4).

(G) Flow cytometric isolation of GFP⁺ cells from the spinal cord of adult FoxJ1-CreER mice based on the IRES-GFP signal (GFP gate). 7-AAD labels dead cells, which were excluded.

(H–K) Brightfield (BF) and fluorescent images (I and K) of a single GFP⁺ sorted cell and a neurosphere (J) formed from such a cell, which is GFP⁻ due to the lack of FoxJ1 expression (K).

Scale bars indicate 400 μm in (E), 20 μm in (F), 100 μm in (H) and (I), and 50 μm in (J) and (K).