The study, published in the Proceedings of the National Academy of Sciences (PNAS), marks a milestone in reproductive science, opening the door to potential future applications in fertility medicine and genetic research.
The team, led by Professor Yanchang Wei, achieved this result by injecting sperm from two male mice into an egg cell that had been stripped of its maternal DNA. Crucially, they applied a method known as epigenome editing, which reprograms gene activity without altering the DNA sequence itself.
“We attempted to improve the development of androgenetic embryos by restoring the epigenetic status of these ICRs [imprinting control regions],” the researchers wrote.
Out of 259 embryos implanted into surrogate female mice, only three pups were born, and two survived into adulthood. Despite the low 0.8% success rate, both surviving mice were able to reproduce normally, proving their fertility and general health.
“Our efforts enabled us to generate androgenetic mice that can develop to adulthood and are fertile, using the genetic materials derived from two sperm cells,” the scientists noted.
This research is based on overcoming genetic imprinting, a process in which chemical labels on DNA determine which genes are active in a given embryo. Normally, imprinting is balanced between maternal and paternal chromosomes, but this balance is disrupted when both sets of chromosomes come from the same sex, often leading to developmental failure.
While scientists managed to generate viable embryos from two female mice as early as 2004, replicating this process with two male mice had remained elusive due to the complexity of correcting paternal imprinting patterns. Wei’s team solved this by targeting and modifying seven key ICRs known to be essential for development.
Despite the promising results in mice, the road to human application remains long and uncertain. “Although the efficiency is low at present, this finding may be an important step toward achieving mammalian androgenesis,” the authors acknowledged. Experts also caution that the low success rate, ethical concerns, and regulatory restrictions make it unlikely that similar techniques will be applied to human embryos in the near future.
Earlier, it was reported that an American scientist achieved a significant breakthrough in understanding how axolotls – Mexican salamanders known for their remarkable regenerative abilities – are able to regrow limbs and organs.