This Mouse Has Two Biological Dads?!

In a lab in Japan, scientists transformed cells from the tails of male mice into eggs. They fertilized the eggs with ordinary mouse sperm and implanted them in surrogate mouse moms. The experiment was repeated 630 times. Although most of the pregnancies failed, seven healthy mice were born. 

Each of those seven baby mice had two biological dads.

The experiment has staggering implications for the future of human reproduction. Biologist Katsuhiko Hayashi, who led the project, predicts that within a decade, a human skin cell could be used to create a viable human egg. The biotech companies Conception Bio and Gameto are already working on this technology.

This would allow same-sex couples to have natural offspring. Perhaps even solo reproduction will be possible, with one man generating both the sperm and the egg.

Some conservatives are alarmed. "The global fertility industry seeks to erase women from procreation one manufactured egg at a time," Jordan Boyd wrote at The Federalist.

Actually, this technology would be empowering for women who want to have children but can't produce viable eggs—or for older women who have already gone through menopause.

Younger women would also benefit. If a piece of skin can be turned into a viable egg, women doing IVF will be saved from daily hormone injections and from needles in their vaginas, both of which are part of the standard retrieval process today.

Ben Hurlbut, a bioethicist at Arizona State University, told USA Today that this technology is "a perversion of the sanctity of procreation as a fundamental aspect of human life."

It's not a perversion of anything. Procreation is a fundamental aspect of human life—and with this technology, more people would be able to take part. Just ask the 9 percent of men and 11 percent of women of reproductive age in the United States who have experienced fertility problems.

Marcy Darnovsky, head of the left-wing Center for Genetics and Society, warned on NPR that this technology could have dystopian consequences, noting that "this could take us into kind of a Gattaca world."

Darnovsky was referencing the 1997 sci-fi movie in which a eugenicist state is ruled by people born with genetically enhanced abilities.

It's true that this technology could allow parents to test their embryos before implantation and select the traits of their future offspring. But IVF already makes this possible. Today, parents routinely test embryos for heritable conditions and for gender. In the future, they may be able to select for more qualities. And there's nothing wrong with that.

As Stanford University bioethicist Hank Greely correctly observes, we should rely on "parental choices to make decisions about how people wish to create families."

This follows from the reasonable presumption that parents generally seek to provide the best lives for their kids. The sorry history of eugenics in the U.S., where tens of thousands were forcibly sterilized during the 20th century, should make anyone cautious about government meddling in people's reproductive choices.

The ability to turn mouse tails into mouse babies could become the latest technology to give humans more freedom to have the lives they choose with the families of their dreams.

This video is based on the essay "What if Men Could Produce Their Own Eggs?," from our February 2024 issue.

Photo credits: K. Hardy (CC BY 4.0), National Institute of Arthritis and Musculoskeletal and Skin Diseases NIH (CC BY-NC-SA 2.0), Atdoan0 (CC BY-SA 4.0), Internet Archive Book Images (CC0 1.0), Bada Bing (CC BY-NC-SA 2.0), Peter Hermes Furian, Zurijeta, 7active Studio, Srckomkrit

Music credits: "Movements," by Skygaze. Licensed by Artlist.

• Graphics Producer: Lex Villena
• Narration: Katherine Mangu-Ward