Table 1.

Production of offspring from ground or space-preserved spermatozoa injected into BDF1 oocytes

Mouse strainCondition of preservationNo. of oocytesNo. of oocytes surviving after ICSINo. (%) of fertilized embryosNo. (%) of two-cell embryos at 24 hNo. of transferred embryos (no. of recipients)No. (%) of offspring
C57BL/6Original1118974 (83)68 (76)68 (4)20 (29)*
Ground267216208 (96)165 (76)165 (8)19 (12)**
Space452367359 (98)262 (71)262 (12)24 (9)**
BDF1Original1109898 (100)74 (76)74 (4)23 (31)*
Ground572423366 (87)278 (66)278 (14)10 (4)**
Space345282256 (91)182 (65)182 (10)15 (8)**
BCF1Original784948 (98)38 (78)38 (3)16 (42)*
Ground270242231 (95)213 (88)213 (10)27 (13)**
Space400341327 (96)279 (82)279 (12)24 (9)**
129B6F1-GFPOriginal1027575 (100)55 (73)55 (3)17 (31)*
Ground180140133 (95)97 (69)97 (4)15 (15)**
Space1208675 (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.)