Scientists in Japan successfully produced living sperm from mice stem cells.
The research, published in an online academic journal Cell, sheds hope as it is a crucial step in treating human infertility.
The experiment was conducted by researchers at Kyoto University by inducing the mice stem cells to create sperm precursors, which were then transplanted into infertile male mice that successfully produced sperm.
The sperm was used to fertilize eggs in vitro, and eventually produced healthy and fertile offspring.
Research team leader Mitinori Saitou told AP "We have high hopes" when it comes to treating infertility in humans, "but it's not that easy" as there are "many difficult issues ahead in applying this to humans. But it is a first step."
Likewise, biology experts not involved in the research agree that while there is still a long road ahead in finding a cure for human infertility, it is certainly an important development.
According to The Telegraph, fertility expert Dr. Allen Pacey commented regarding the research: "This is quite a step forward in developing a process by which sperm could be made for infertile men, perhaps by taking as a starting point a cell from their skin or from something like bone marrow.
"Clearly more work needs to be done to refine this process, but it's hugely exciting."