"It has been a weird project, but we wanted to see if it could be done," said Richard Behringer, lead author of a bizarre new study that has used stem cells to produce a living offspring from two male mice, according to the Wall Street Journal.
Some might call it mad science, but the successful production of two-father offspring in a species of mammal could eventually open the door to wondrous things, such as preserving endangered species, improving livestock breeds, and even allowing same-sex couples the possibility of parenting their own genetic children.
To pull off the experiment, researchers had to get creative with stem cells. First they took cells from a male mouse and transformed them into a line of induced pluripotent stem cells. Since the mouse was a male, the new batch of stem cells had, as should be expected, X and Y sex chromosomes. But a few of the cells (just 1 percent of them) dropped the Y chromosome due to mistakes during cell division.
The scientists then took these Y-less cells (technically called XO cells, since they still retain their X chromosomes) and injected them into early stage mouse embryos which had been produced normally. The injected embryos were then implanted into a mouse mother, which eventually gave birth to offspring, some male and some female, which retained some cells from the original XO line.
The next and final step involved breeding females from this last generation of offspring with normal male mice. Since some of those females retained egg cells which derived from the XO line from the original male mouse, they gave birth to babies that had genetic material from both the original male mouse and their natural father.
Thus, abracadabra! A mouse is born, in a roundabout way, from two fathers.
"It may also be possible to generate sperm from a female donor and produce viable male and female progeny with two mothers," the researchers added.
The process is still a bit crude to be used with humans, but it at least opens the door to some wild possibilities. Same-sex couples could actually produce children, and it would be a major breakthrough for human-assisted reproductive technology.
For endangered species, it could allow scientists to preserve genetic diversity and produce new offspring even when few or no females of the species remain. Furthermore, preferred traits from livestock animals could be selected for without the need to outcross to females with diverse traits.
The technology could ultimately mean a lot more than just an advance in reproductive science. In a vague sense, you could even say that this research has created a new form of mammalian reproduction entirely.