Mice born of two parents is a fascinating process which ultimately gives rise to the little creatures that have become so beloved by many people today. The combination of genes provided by both the male and female ensure that the offspring of a pair of mice will be as healthy and diverse as can be. Through selective breeding, researchers can even increase the overall desirable characteristics of a type of mouse, making them more and more adapted to their environment and more interesting to study.
The feat was accomplished in Japan. Cells from two male mice were used to implant into female mice. Thus mice born from two parents were obtained. The finding was announced during the Third International Summit on Human Genome Editing.
It is a possible alternative for severe infertility problems. And it raises the possibility of same-sex couples being able to have a biological child in the future. “It has important potential applications,” said Keith Latham. He is a developmental biologist at Michigan State University.
Low survival
Researchers have been working for years to achieve the result. The possibility of working these cells to make them functional has been studied before. Katsuhiko Hayashi, from Osaka University, took the lead. He started a project to create eggs using cells taken from an adult male mouse.
They cultured them until some of them spontaneously lost their Y chromosomes. Then they treated the cells with a compound called reversin. And they looked for cells that were chromosomally female, with two copies of the X chromosome. Then they fertilized the eggs with mouse sperm. And they transferred the resulting embryos into the uterus of a female mouse.
The survival rate was low. Of 630 embryos transferred, only 7 developed into offspring. However, the offspring grew normally and were fertile as adults. This is still a long way from having applications in humans. But already the achievement is astonishing.
Ethical issues
Says bioethicist Tetsuya Ishii of Hokkaido University in Sapporo, Japan. The ramifications of Hayashi’s work could take human reproduction into new territory.
If applied to humans, this research could help male couples have biological children together. Although it would always be with the help of surrogate mothers. “It also suggests that an unmarried man could have a biological child in the distant future,” he envisioned.
Mice born to two parents are just the beginning. Although this calls for a wide-ranging debate about its possible application. “I don’t know if this kind of technology can really be adapted to human society,” Hayashi posited.
