A research group from Osaka University and others is making an egg from iPS cells of a male mouse and fertilizing it with the sperm of another mouse to give birth to a child. This is the first time in the world that eggs have been produced from male mice, and the group hopes to help conserve animals that are at risk of extinction.
In mammals such as humans and mice, the biological sex is determined by the sex chromosomes "X" and "Y" in the cells, and males have one X and one Y, and females have two X.