[10/18/16] Scientists have successfully turned mouse skin cells into egg cells and used them to create viable offspring without the use of actual eggs for the first time.
Just a small percentage of the mouse cells created in the lab led to live births, researchers reported Monday in Nature, but the healthy pups that resulted from these sci-fi pregnancies provide hope that similar techniques might one day aid human reproduction.
The new study is the culmination of years of incremental progress: Researchers began by coaxing cells from female mouse tails into pluripotent stem cells using a technique that won Shinya Yamanaka a Nobel Prize in 2007. Pluripotent cells have the potential to divide indefinitely and become any kind of body tissue, and they are the type of cells found in embryos. The next step was to turn those pliable cells into sex cells. Katsuhiko Hayashi, a reproductive biologist at Kyushu University and lead author of the new study, helped to develop a technique for doing so while at the University of Kyoto in 2012.
But that previous work produced the kinds of sex cells that exist in an embryo, not mature eggs that could actually be fertilized and used to create offspring. Until now, researchers had been able to mature those cells only by implanting them back into an ovary. A study published in September was widely reported as involving the creation of embryos without eggs, but this was not actually the case – an egg was used, albeit in an unconventional fashion.
