Scientists at Stanford University claim they've found a way to make human embryonic stem cells turn into the types of cells that ultimately form sperm and eggs.
Nature, may shed light on human reproduction, development and infertility.
CBS News medical correspondent Dr. Jennifer Ashton explained how the scientists did it: "They took unused embryonic stem cells ... and then they put them in a lab, gave them some special cocktail of nutrients, proteins, some chemicals, and coaxed them into developing into early sperm and early eggs."
However, the sperm weren't perfect.
"They had little, short tails," Ashton said, "and the eggs were much earlier than those that could actually be fertilized. But they are hailing this as a major breakthrough because it was really the first time that stem cells were used to achieve this purpose."
"Early Show" co-anchor Maggie Rodriguez pointed out, there are ethical concerns with this possible fertility development. The stem cells, for instance, were used from embryos that were discarded and not used for fertility treatments.
Ashton added there are biological questions, as well, because this is the first time anything like this has been done.
"It will lend a lot more information, not only into the treatment of fertility problems, but also just overall human development," she said. "But of course, there are moral and ethical issues that are sure to be causing quite a commotion."
How could this actually play out for people seeking help with fertility?
"One-in-six couples suffers from infertility," Ashton said. "And while there are a lot of causes, ranging from infections like STDs, to problems with anatomy, a large percentage of couples are infertile because there are actual problems with either the sperm and/or the eggs. So potentially, this is a major therapeutic breakthrough -- with a lot of issues attached, of course."
As for putting this development into practice for patients, Ashton said it's going to take a while. "Just because something is done in a lab means, of course, it could be years, if not decades, until it could be brought to an actual patient," she said.
Rodriguez also mentioned possible quirks of the development, asking, "If you take the stem cells from a female embryo, you get an egg. If you take it from a male embryo and make a sperm, babies that come from those sperm and eggs will be the biological children of that embryo?"
Ashton said that's right, adding, "The big thing here is that, in order to create an egg right now, you need female DNA and with a sperm, you need male DNA," she said. "So, again, in the future, this is going to be very complicated, but there's the potential to develop an egg from a man's DNA. And that's what they're going to be looking at."