Scientists Turn Stem Cells Into Working Sperm

Researchers have managed to produce sperm cells from embryonic stem cells—and for the first time, the sperm worked, resulting in healthy baby mice. Researchers in Japan mixed the embryonic stem cells with certain proteins and hormones. They converted the resulting cells into germ cells, which they implanted in the testes of mice. There, they developed into working sperm, Discover reports. Researchers hope the discovery will lead to male infertility treatments, notes ScienceNow.

Scientists had previously created sperm-like cells, but they didn’t function. Though the experiment was a success, “very difficult” issues remain—both physical and ethical, says a researcher. For one thing, the scientists would like to generate the sperm cells in the lab, without having to involve the mice at all. They hope to generate eggs, too. But questions remain over whether the process used for mice will work on humans. (More sperm stories.)