How far can stem cells and gene editing take us? A recent study shows how scientists were able to create healthy mice broods from same-sex parents.
Having parents of the same sex is not impossible in the animal kingdom. In fact, this has been observed in several species of reptiles, fish, and amphibians. In mammals, however, it is much trickier even with the help of current fertilization technology. This is because mammal offspring that do not receive genetic material from the mother and the father in the process of genetic imprinting may develop abnormalities or may not even be viable at all.
In a recently published study in the journal Cell Stem Cell, scientists from the Chinese Academy of Sciences describe how they were able to successfully develop a healthy brood of mice from same-sex parents with the help of stem cells and gene editing. Specifically, the scientists produced normal mice from same-sex parents using haploid embryonic stem cells with gene deletions.
Two Mothers And Two Fathers
To do this with two mouse mothers, the researchers deleted three imprinting regions of the genome from haploid embryonic stem cells (ESC) from a female mouse and injected it into another female mouse’s egg cell. Amazingly, they were able to give birth to 29 live, normal mice that lived to adulthood and even had their own broods.
The process was a bit trickier and less successful in male mice, however, as the researchers had to inject the haploid ESC together with sperm cells into an egg cell that has had its female genetic material removed and then injected into surrogate mothers. This process was able to produce a dozen two-male mice babies, but they lived for just 48 hours after birth.
Even so, the researchers hope to study the techniques further in the future using other research animals.
“This research shows us what’s possible,” said study co-author Wei Li, also noting that their study could be useful in future studies of genomic imprinting and animal cloning.
Naturally, such genetic manipulation brings to light certain ethical considerations among experts, particularly when it comes to the eventual health of the offspring, as shown in how the two-male babies ended up not living for very long after birth.
Some experts are concerned about how gene editing could lead to inadvertent negative side effects that could be passed on from generation to generation, while others are concerned about the implications of the study, stating that humans should think about what the threshold for this kind of research should be.