To test this possibility, Japanese researchers sent freeze - dried mouse sperm up to the space station, where the sperm spent nine months. (sciencenews.org)
Further, they noticed that this RNA found its way into mouse sperm. (scientificamerican.com)
A team in Japan made mouse sperm in the lab in 2011, but the French researchers claim they are the first to do this in humans. (newscientist.com)