Are men redundant? Baby mice created using two mothers and no father

Scientists in China have managed to combine genetic material from two female mice to successfully create offspring. The ground-breaking experiment saw researchers from the Chinese Academy of Sciences' Institute of Biochemistry and Cell Biology genetically modify an ovum-derived embryonic stem cell – the female sex gamete – and inject it into an ova to successfully produce a litter of baby mice.

"The entire process does not require any male involvement," said Professor Li Jinsong, the lead author of the study. "Sperm is replaceable – that's clear from the experiment. All we need are a pair of eggs, and from these eggs we can create a family, a colony, even a kingdom of healthy pups."

The team had initially set out to identify the generic similarities between stem cells in ova and sperm, and then curiosity got the better of them when they were intrigued to see what would happen if they injected an ovum-derived embryonic stem cell into an egg, according to the research paper published in the journal Cell Research. After a period of trial and error, they found that two genes known as H19 and Gtl2 could affect the "bad impression" that the female cells had on one another.

Li said: "The first impression is always important. Natural eggs have a bad impression on each other, so they never combine," according to a report in the South China Morning Post. By quashing the mechanisms of how the two genes interact with the egg-derived stem cell, they were able to introduce it to another egg.

However, Li said that there was only a 15% success rate and this shows that it is unethical to use on humans. "However well we improve the technology, it cannot be 100% safe," he said. "We should therefore never use it on humans. Nature has created men and women, and the difference must be for good reasons. Cheating on that will not only generate an ethical crisis but lead to unpredictable consequences such as bad mutations and diseases."

Li said that it was impossible to create offspring using two sperm. "Two sperms will not create a baby," he said. "You always need an egg. Sperm is much smaller and simpler than an egg. It is possible to turn an egg into sperm, but the opposite direction is much more difficult."