Table 2. Expansion of SSCs during long-term culture.
| Days to transplant 1 | Passage | Colonies/105 (n) | Increase in total cell number (fold) 2 | Increase in SSC number (fold) 3 | |
|---|---|---|---|---|---|
| DBA | 0 | 0 | 275.0 ± 52.0 (4) | 1 | 1 |
| 43 | 8 | 275.0 ± 75.0 (4) | 5.022 × 107 | 5.022 × 107 | |
| 91 | 18 | 225.0 ± 76.1 (6) | 1.736 × 1016 | 1.420 × 1016 | |
| 140 | 30 | 160.0 ± 43.0 (5) | 5.030 × 1024 | 2.92 × 1024 | |
| B6-MHY | 0 | 0 | 58.3 ± 37.5 (6) | 1 | 1 |
| 43 | 8 | 300.0 ± 167.1 (4) | 6.010 × 106 | 3.090 × 107 | |
| 91 | 16 | 558.3 ± 126.8 (6) | 4.947 × 1013 | 4.737 × 1014 | |
| 140 | 28 | 620.0 ± 131.0 (5) | 3.806 × 1021 | 4.048 × 1022 | |
GS cells established from Green mice were cultured on MEFs. In each experiment, 2.0–8.0 × 103 cells were microinjected into the seminiferous tubules of infertile recipient testes. The results are presented as means ± SEMs. 1 The number of days from initiation of culture to transplantation. 2, 3 The increase in the total cell (2) or SSC number (3) from the initial transplantation.