Space-frozen sperm give birth to healthy offspring

if NASA wants to send humans to Mars, the trip has an indispensable must-have: sperm. A wide variety of human sperm will ensure the genetic diversity of the new colony, which is important for healthy animal populations. But no one knows whether reproductive cells can withstand the destruction of cosmic radiation.
, however, researchers say sperm from laboratory mice that have been frozen and dried for nine months on the International Space Station (ISS) not only produce healthy "space rats" through artificial insemination, but also give birth to healthy offspring.
" study is important. Steven Peck, a biologist at Brigham Young University in Utah who was not involved in the study, said.
2013, Teluhiko Wakayama, a professor at Yamanashi University in Japan, and colleagues sent sperm from 12 mice to ISS after it had dried. The astronauts stored the specimens in a freezer at minus 95 degrees Celsius for 288 days. On Earth, the team also took sperm from the same mice and stored it at the same temperature for the same time.
samples were brought back to Earth in May 2014. Since the amount of cosmic ray radiation exposed to ISS is about 100 times that of Earth, most of the sperm in these laboratory mice has DNA damage. The researchers used the sperm brought back from space to grow fertilized eggs, resulting in 73 "space rats" with little difference in reproductive success rates from those of laboratory mice that had been preserved on Earth for the same time.
addition, Wakayama et al. reported in the U.S.
Web edition that the appearance and life span of "space rats" are no different from that of ordinary laboratory mice, and that "space rats" can reproduce normally, producing healthy great-grandchildren. The genes of all "space rats" and their offspring are no different from those of ordinary laboratory mice.
results show that DNA damage is repaired after fertilization. The researchers say it may be that DNA repair functions from eggs play a role, but damage caused by longer-term preservation in space may be difficult to repair. In the future, they will use sperm stored in space for three to five years to carry out the same experiments, and even try to grow fertilized eggs in space. (Source: Science Network Tang 1 Dust)