A team of researchers in China has successfully created and raised mice with two biological fathers, marking a significant breakthrough in genetic engineering. Led by Zhi-Kun Li at the Chinese Academy of Sciences, the team employed CRISPR gene-editing technology to circumvent the natural barriers of imprinting, a process that typically requires genetic contributions from both male and female parents. By targeting 20 key imprinted genes, the scientists manipulated sperm-derived stem cells and combined them to create embryos containing DNA from two male mice. These embryos were then implanted into surrogate mothers, resulting in live births for the first time using this method. While only a small fraction of the embryos survived, those that did reached adulthood, albeit with notable abnormalities, including oversized organs, shortened lifespans, and infertility.
The implications of this research extend beyond mice, raising profound questions about the future of reproductive biology. While human applications remain far from reality due to ethical and technical constraints, this study contributes to a growing body of work exploring alternative pathways for mammalian reproduction. Scientists are now investigating whether similar techniques could be used to create primates with two biological fathers, and in the long term, whether they could one day allow humans to produce offspring without the need for egg or sperm donors. However, the study also underscores the risks involved, as imprinting errors could lead to severe developmental disorders. As genetic science advances, society may need to redefine traditional notions of parenthood and grapple with the ethical dilemmas posed by such radical innovations in reproduction.
