Age-related sites for hematopoiesis in normal mice
| Factor . | Cells from . | No. of colonies . | |
|---|---|---|---|
| Per 105 . | Per femur or spleen . | ||
| Bone marrow | |||
| IL-3 | 2-day-old | 281.5 ± 17.5 | 2083 ± 128 |
| IL-3 | 8-week-old | 551.5 ± 56.0 | 45 499 ± 4620 |
| IL-7 | 2-day-old | 208.5 ± 27.5 | 1543 ± 204 |
| IL-7 | 8-week-old | 158.5 ± 13.0 | 13 077 ± 1073 |
| Spleen | |||
| IL-3 | 2-day-old | 361.5 ± 47.5 | 19 087 ± 2508 |
| IL-3 | 8-week-old | 10.0 ± 5.0 | 10 300 ± 5150 |
| IL-7 | 2-day-old | 43.5 ± 17.5 | 2297 ± 924 |
| IL-7 | 8-week-old | 0 | <343 |
| Factor . | Cells from . | No. of colonies . | |
|---|---|---|---|
| Per 105 . | Per femur or spleen . | ||
| Bone marrow | |||
| IL-3 | 2-day-old | 281.5 ± 17.5 | 2083 ± 128 |
| IL-3 | 8-week-old | 551.5 ± 56.0 | 45 499 ± 4620 |
| IL-7 | 2-day-old | 208.5 ± 27.5 | 1543 ± 204 |
| IL-7 | 8-week-old | 158.5 ± 13.0 | 13 077 ± 1073 |
| Spleen | |||
| IL-3 | 2-day-old | 361.5 ± 47.5 | 19 087 ± 2508 |
| IL-3 | 8-week-old | 10.0 ± 5.0 | 10 300 ± 5150 |
| IL-7 | 2-day-old | 43.5 ± 17.5 | 2297 ± 924 |
| IL-7 | 8-week-old | 0 | <343 |
Freshly prepared bone marrow cells and spleen cells were cultured in methylcellulose semi-solid medium with IL-3 or IL-7 for 7 days. The numbers of cells recovered per femur were 0.74 × 106 and 8.25 × 106 from 2-day-old and 8-week-old mice, respectively. The numbers of cells recovered per spleen were 5.28 × 106 and 103.0 × 106 from 2-day-old and 8-week-old mice, respectively. Data are expressed as the mean ± SD of triplicate cultures.