Researchers in China were able to create mice offspring using DNA from mice parents of the same gender using gene-editing technology.

Conducted by researchers at the Chinese Academy of Sciences in Beijing, the study is now being seen as a huge breakthrough, especially for gay couples who want to have their own biological children.

Using embryonic stem cells, the scientists made egg-like and sperm-like structures, according to Nature. They then edited the cells to remove parts of DNA that normally block reproduction using only male or female genes.

In creating the “mothers only” mice, the researchers simply injected edited stem cells directly into the egg, which was then implanted into another female mouse.

As for the “fathers only” mice, they did a more complicated procedure which involved injecting edited embryonic stem cells from one father into an egg cell alongside sperm from a second father.

To ensure that no female genes made it into the eventual offspring, the DNA from the egg cells were removed.

Combining genes from two females, the research team was able to produce 29 healthy mice, without sperm from a father. The offspring eventually grew into healthy adults and even had their own healthy children.

Meanwhile, using DNA from two males resulted in the birth of 12 mice which died just 48 hours after they were born. Some even resulted in “gruesome genetic mutations” such as longer tongues and abnormally large bodies.

Despite the discouraging results from the male-only unions, the scientists are confident that such a technique could one day also be used in creating humans whose biological parents are both women or both men.

Study author Qi Zhou, a developmental biologist, said their findings showed “a new and clear way to produce offspring between same-sex mammals.”

Featured image via Science Direct/Leyun Wang