April 14, 2024

“Virgin birth” mouse rewrites textbook on reproduction

Kaguya with kids

Scientists at the Tokyo University of Agriculture have created a mouse from two eggs without the involvement of sperm or other male cells. Their experiment is being hailed as important as the birth of Dolly the cloned sheep in 1996. Until now, it was believed that two mammals of the same sex cannot combine their genomes to produce viable offspring.

Although the news instantly prompted speculation about the redundancy of men, it is unlikely that the procedure could ever be used to create children for two women. For one thing, it is enormously wasteful: about 600 eggs yielded a single healthy adult mouse. However, it will have an enormous impact upon reproductive science as it gives an insight into the poorly understood process of genetic imprinting. The Japanese scientists were able to alter the expression of two imprinted genes and this had a ripple effect upon the rest of the genome. Their work will eventually help scientists to understand many genetic abnormalities and to optimise fertility techniques.

According to the bioethicist most quoted by the US media, the “virgin birth” also has implications for the stem cell debate. Writing in the San Jose Mercury, Dr Arthur Caplan, and a colleague from Stanford University argue that the development of an egg into a mature individual makes a nonsense of the notion that “potentiality” is the foundation of personhood. Although eggs have now been shown to be potential embryos, everyone would agree that it is absurd to mourn the death of eggs as if they were persons, they claim. Dr Caplan has consistently criticised the idea that an embryo is a person and has rights.

In any case, asexual reproduction may not be good idea for the species. According to research by evolutionary biologist Dr Joel Peck of the University of Sussex it could lead to extinction. “My theory predicts that, if a species becomes asexual, then it will also become progressively nastier so that helpful behaviour almost never occurs… If humans became an asexual population, then it seems very likely that we would quickly wipe ourselves out through sheer antagonism,” he says.