Table 1.
Production of offspring from ground or space-preserved spermatozoa injected into BDF1 oocytes
| Mouse strain | Condition of preservation | No. of oocytes | No. of oocytes surviving after ICSI | No. (%) of fertilized embryos | No. (%) of two-cell embryos at 24 h | No. of transferred embryos (no. of recipients) | No. (%) of offspring |
| C57BL/6 | Original | 111 | 89 | 74 (83) | 68 (76) | 68 (4) | 20 (29)* |
| Ground | 267 | 216 | 208 (96) | 165 (76) | 165 (8) | 19 (12)** | |
| Space | 452 | 367 | 359 (98) | 262 (71) | 262 (12) | 24 (9)** | |
| BDF1 | Original | 110 | 98 | 98 (100) | 74 (76) | 74 (4) | 23 (31)* |
| Ground | 572 | 423 | 366 (87) | 278 (66) | 278 (14) | 10 (4)** | |
| Space | 345 | 282 | 256 (91) | 182 (65) | 182 (10) | 15 (8)** | |
| BCF1 | Original | 78 | 49 | 48 (98) | 38 (78) | 38 (3) | 16 (42)* |
| Ground | 270 | 242 | 231 (95) | 213 (88) | 213 (10) | 27 (13)** | |
| Space | 400 | 341 | 327 (96) | 279 (82) | 279 (12) | 24 (9)** | |
| 129B6F1-GFP | Original | 102 | 75 | 75 (100) | 55 (73) | 55 (3) | 17 (31)* |
| Ground | 180 | 140 | 133 (95) | 97 (69) | 97 (4) | 15 (15)** | |
| Space | 120 | 86 | 75 (87) | 61 (71) | 61 (3) | 10 (10)** |
Original: When samples were prepared, some ampules were used to check the quality of each lot. These data were used as the original control. Ground: At the same times and for the same durations as when launching and storing the sample case, a control sample case was exposed to room temperature, then frozen at –95 °C and stored in a freezer at the Tsukuba Space Center in Japan. These are referred to as ground control sperm samples. Space: Samples were launched and stored on the ISS for 9 mo. (* vs. **: P < 0.05.)