Figure 1

Characterization of 129/Ola murine ES cells and of ES-derived neurospheres . (A) Phase contrast image of ES cell colonies with the characteristic compact morphology. (B) ES cells colonies show a high expression of the stem cell marker alkaline phosphatase. Calibration bars = 25 μm. (C) Phase contrast micrograph of ES-derived neurospheres (ES-NS) after 7 days in culture in serum-free medium supplemented with growth factors (NB27 + GF) and (D) immunofluorescence analysis showing the expression of the neural stem cell markers nestin (red). Nuclei are counterstained with DAPI (blue). Calibration bars = 25 μm. (E) Western blot analysis of nestin expression in ES-NS compared to ES cells grown under regular conditions. n = 3 ** P < 0.01 One Sample T test. (F-I) Immunofluorescence analysis of ES-NS showing the expression of the neural crest stem cell marker p75 (red); of the neuronal progenitor marker βIII-tubulin (red); and the lack of expression of the neuronal marker PGP9.5 (green) and of the glial marker GFAP (red). Nuclei are stained with DAPI and are shown in blue. Calibration bars = 25 μm. (J) Western blot analysis of ES-NS.