Notch controls proliferation and differentiation of stem cells in a dose-dependent manner
In the recently published paper of Guentchev & McKay (2006), on page 2291, the first three parts (a, b and c) of Fig. 1 were missing. The corrected Fig. 1 is reproduced here, with its original legend for completeness.
Density-dependent effects on the cell cycle in central nervous system (CNS) stem cells. (a) Low cell density correlates with a very slow rate of BrdU incorporation. An increase in density primarily results in an increase in the proliferation rate. When the peak is reached at 1.25 × 104 cells/cm2 any further increase of density leads to reduction of the proliferation rate. Differences between conditions 0.47 and 5.00 on one side and 1.25 on the other were highly statistically significant [P < 0.0001; Mann.Whitney U-test; confidence interval (CI) 95%]. (b) Density-dependent p21WAF1/CIP1 expression in CNS stem cells. Increase of cell density correlates with a boost of p21WAF1/CIP1 expression. There is also an increase of p21WAF1/CIP1 expression in the very low-density cultures. Differences between data points 0.47 and 5.00 on one side and 1.25 on the other were statistically significant (P = 0.0026 and P = 0.0007, respectively; Mann.Whitney U-test; CI 95%). (c) Notch, bone morphogenetic protein receptor (BMPR)1A, BMPR1B, βIII-tubulin and glial fibrillary acidic protein expression in CNS stem cells plated at different densities. Lanes: (1) 0.63 × 104, (2) 1.25 × 104, (3) 2.50 × 104 and (4) 5.0 × 104 cells/cm2 grown for 36 h in the presence of bFGF. Protein loading was normalized to α-tubulin expression. (d) Phase-contrast images of the biological assay and immunofluorescent staining of nucleostemin and phospho-SMAD1/5/8 at different plating densities.
The authors apologize for any confusion that this may have caused.
