TABLE 1.
Development of oocytes injected with sperm from caput vs. caudal epididymis.
| Sperm source | Mouse strain | Sperm treatment | Oocytes surviving injection (%) | 2-cell embryos at 24 h (% surviving) | No. embryos transferred (no. recipients)a | No. live offspring (% implantations) |
| Caput | B6D2 | Freezing/thawing | 167/192 (86.9) | 134 (80.2) | 134 (5) | 15 (11.2) |
| Cauda | B6D2 | Freezing/thawing | 90/116 (77.6) | 78 (86.7) | 78 (4) | 19 (24.4) |
| Caput | B6D2 | DWG T syringe | 46/53 (86.8) | 35 (76.1) | 35 (2) | 3 (8.6) |
| Cauda | B6D2 | DWG T syringe | 44/60 (73.3) | 36 (81.8) | 36 (3) | 6 (16.7) |
| Caput | B6 | DWG T syringe | 39/50 (78) | 32 (76.9) | 32 (2) | 2 (6.3) |
| Cauda | B6 | DWG T syringe | 38/50 (76) | 31 (81.6) | 31 (2) | 5 (16.7) |
Four independent experiments were conducted. B6D2 = C57/BL/6 JxDBA/2 J; B6 = C57BL/6NHsd; DWG T syringe = Drawing through syringe. aAll recipients were pregnant. P > 0.05 Chi-square analysis.