Professor Katsuhiko Hayashi of Osaka University Graduate School of Medicine has been selected as one of the 2023 "10 People of the Year" by the British scientific journal Nature. This work was highly praised for being the first in the world to succeed in producing eggs from male mouse iPS cells and birthing a child using only male cells.
According to Osaka University, the sex of mice is determined by the combination of X and Y chromosomes, just like humans, with males having one X and one Y chromosome, and females having two X chromosomes. Professor Hayashi cultivated iPS cells made from males, extracted cells from which the Y chromosome had naturally disappeared and only had one X chromosome, and then selected cells that had become two X chromosomes through cell division. .
The eggs produced by culturing these cells were fertilized with the sperm of another male, and when the fertilized eggs were implanted into the uterus of a female surrogate mother, seven mice were born. All mice were born with normal fertility.
This research result, born from an original idea, has paved the way for the rescue of rare animals on the brink of extinction, and by applying it to humans, it has been possible to treat male-male couples and cases in which one of the two X chromosomes is missing. It is thought that it will be technically possible for women with Turner syndrome to have children.
In a news feature on its website, Nature quotes comments from biologists from Japan, the United States, and the United Kingdom, calling the research results groundbreaking and rewriting the rules of sexual reproduction.
