Similar to how researchers recently developed a process for growing heart tissue from stem cells, the paper's lead author Katsuhiko Hayashi and his team first turned skin cells from the tails of female mice into stem cells using a Nobel Prize-winning process developed in 2007. The stem cells then became sex cells using a process Hayashi developed back in 2012. Finally, the immature sex cells were placed in a petri dish alongside cells from mouse ovaries, which essentially tricked them into growing as mature egg cells that could be fertilized to produce offspring. Hayashi's team was also able to create the egg cells using skin cells from male mice, meaning it could one day lead to offspring with two biological fathers.

While the same process could theoretically work with human stem cells, that sort of research and experimentation definitely won't be happening anytime soon due to high failure rates and ethical concerns. Until then, the next step for Hayashi's team is to recreate the experiment with primate subjects.