Table 1.
Summary of the effects of p21 loss on in vivo and in vitro neural stem cell function (all effects are p21−/− relative to p21+/+
| 60-d p21−/− | 480-d p21−/− | |
|---|---|---|
| In vivo neural stem cell function | ||
| Primary neurosphere number in SE | Increased | Decreased |
| Long-term BrdU-labeled cells in SE | Increased | Decreased |
| Ki67-labeled cells in SE | No change | Decreased |
| Neurogenesis in OB | No change | Decreased |
| Primary neurosphere culture | ||
| Rate of BrdU incorporation | Increased | Decreased |
| Cell expansion | Increased | Decreased |
| Neurosphere volume | Increased | Decreased |
| Cell death | No change | No changea |
| Multipotentiality | No change | No change |
| Neurosphere passaging | ||
| Exhaustion (passage number) | 5 | 4 |
| Decline in symmetric divisions | Yes | Yes |
| Decline in cell expansion | Yes | Yes |
| Decline in BrdU incorporation | Yes | nd |
| Increase in cell death | No | Noa |
| Change in multipotentiality | No | No |
(BrdU) bromo-deoxy-uridine; (SE) subependyma; (OB) olfactory bulb; (nd) not determined.
a
data not shown.