Mice have been used to produce viable monkey sperm using tissue transplanted from the testes of macaques.
The US scientists involved say their work might one day help to conserve animals that are facing extinction.
It might also be possible to grow human sperm in mice, although the team agree this would be a controversial move.
The researchers, from the universities of Pennsylvania and California, report their studies in the latest issue of the journal Biology of
Reproduction.
In 2002, the same team produced goat and pig sperm from mice. It was the first time that sperm had been produced outside the original animal.