Effects of p57Kip2 induction/repression on OPC cell cycle and morphology
| Average OPC clone size | Hours/division | % OL clones | Average OL clone sizes | |
|---|---|---|---|---|
| Young OPCs, p57 increase | ||||
| -T3 GFP only | 16.7 ± 1.5 | 23.6 ± 2.1 | 1.3 ± 1.3% | 1.0 ± 0.0 |
| -T3 CMV-p57 | 6.0 ± 0.6 | 37.0 ± 3.8 | 14.1 ± 3.9% | 3.1 ± 0.8 |
| +T3 GFP only | 12.6 ± 1.4 | 26.2 ± 3.0 | 11.7 ± 3.7% | 4.3 ± 0.8 |
| +T3 CMV-p57 | 4.9 ± 0.6 | 41.8 ± 5.5 | 41.0 ± 5.6% | 2.1 ± 0.2 |
| Young OPCs, p57 knock-down | ||||
| -T3 siControl | 13.9 ± 1.5 | 25.3 ± 2.7 | 11.1 ± 4.3% | 3.7 ± 1.3 |
| -T3 sip57 | 21.9 ± 2.3 | 21.6 ± 2.2 | 0.0 ± 0.0% | - |
| +T3 siControl | 7.1 ± 0.8 | 33.9 ± 3.7 | 25.5 ± 6.1% | 3.4 ± 1.0 |
| +T3 sip57 | 17.8 ± 1.8 | 23.1 ± 2.3 | 7.4 ± 3.6% | 3.3 ± 0.9 |
| Older OPCs, p57 knock-down | ||||
| -T3 siControl | 2.9 ± 0.2 | 63.2 ± 5.2 | 15.4 ± 5.0% | 1.8 ± 0.4 |
| -T3 sip57 | 6.1 ± 0.6 | 36.9 ± 3.6 | 1.9 ± 1.9% | 1.0 ± 0.0 |
| +T3 siControl | 2.8 ± 0.3 | 64.8 ± 7.3 | 54.7 ± 6.8% | 1.6 ± 0.2 |
| +T3 sip57 | 4.0 ± 0.4 | 48.2 ± 4.6 | 23.1 ± 5.8% | 2.3 ± 0.4 |
Tabulated results of clonal size and morphology assays described in Figure 3, A and B, and Figure 4 A–D. In all conditions, only clones containing transfected (GFP+) cells were counted; 50–80 clones were counted per condition. Young OPCs were transfected after 7 DIV in +PDGF -T3 medium; older OPCs were transfected after 28 DIV in +PDGF -T3 medium and then cultured 4 DIV +PDGF ±T3. ″OPC clones″ contain <50% OLs (by morphology); ″OL clones″ contain ≥50% morphologically complex OL-like cells. Hours per division are calculated as 96 h/log2 (average OPC clone size). All data presented are ± SEM or SE of the proportion in percentage of OL clones.