A group of scientists have been able to create a mouse using only male DNA. No female was involved in the creation of this animal apart from them being used as incubators for the all-male created offspring. The scientists used stem cells from two adult male mice and created embryos which were later placed into surrogate mothers.
Since the female genes are missing, the embryos had to be genetically modified in order to grow enough to be born. Sadly, these pups created only by using male DNA died a short few days after birth. On the other hand, some mice that used only their mothers DNA were able to reach adulthood and some even had offspring of their own.
Scientists performed these tests in order to determine why mammals only reproduce sexually, and when two parents of the opposite sex are present. Other vertebrates though are sometimes able to reproduce even when only one parent is present. This group so far contains sharks, turkeys, and snakes. In females of those species, there is a chance that an unfertilized egg produces fully functional offspring.
Until now, researchers were never able to achieve androgenesis, male-only reproduction in mammals. There has been a case where researchers were able to make a zebrafish with only a father’s DNA sample, but, until now, no such experiment worked on mammals.
In the most recent experiment, where only a mother’s DNA was used, the mouse pups were somewhat smaller than usual. This happens due to the fact that some genes that are inherited from the mother are imprinted, and imprinting causes some genes to be more or less active than usual.
To combat this, scientists used CRISPR to remove three imprinted regions near genes important when it comes to the production of an embryo. The pups that came from these genes grew up normally and achieved normal fertility.
For the all-male pups, the results are much less promising as only one percent of the 1,023 embryos produced pups. In these cases, the scientists had to cut out six regions of DNA in order to create genes that were able to produce a functioning embryo. But the pups were born too big and died soon after birth. Cutting an additional region created smaller pups, but they lived only 48 hours at best.
This research offers great insight into how the imprinted regions affect normal gene development. If scientists are able to better understand how this works they may even be able to save some endangered species. The last northern white rhinoceros died earlier this year and if we were able to produce offspring from only male specimens that might not have happened.
The process is expensive but well worth looking into.