Instead of using and egg as nature does, scientists have succeeded to produce live baby mice by injecting sperm into a modified inactive mouse embryo. The little mice were healthy at a rate of 24 percent, and it is the first time full-term live mice are born from something different than an egg. This finding could mean a new era for endangered animals and fertility treatments.
The study proves that eggs are not the only cells that can form embryos with sperm, and skin cells and other could replace the egg when it comes to fertility. The research was published Tuesday in the Journal Nature Communications and its lead author, Tony Perry, said this work challenges the embryologist’s dogma born in the 1800s.
Perry is an embryologist at Bath University, where he lead the research and stated embryologists have believed since they first observed mammalian eggs, around 1827, and 50 years later, that only an egg cell fertilized by sperm cell can result in live mammalian birth.
Scientists involved in the study explain how they took mouse eggs and used a chemical to trick them into developing as if they had been fertilized. This process was discovered in the past, and the unfertilized, slightly produce embryos are called parthenogenotes. But because they do not have sperm, these immature embryos die soon from developmental processes. The inactive embryos behave similarly to skin and other cells in the body.
Creating mouse pups
After creating the peculiar embryo, scientists injected sperm into them. What they discovered was that rather than dying, the inactive cell develops normally. Then, they were transferred to female mice, and the experiment showed the efforts led to apparently healthy mouse pups.
The study created 30 pups from parthenogenotes with a success rate up to 24 percent. And amazingly, some of the mice born in the latest study had their own puppies, and some of them have had offspring too. During the study, the animals show no signs of harm by the procedure.
Paul Colville-Nash from the Medical Research Council, which funded the study, stated the new research might help the scientific community to understand more about how human life begins and what controls the viability of embryos, which are essential, so far, in fertility. He continued and said that even one day this research might have implications for treating infertility.
Unfortunately, the study discovered that mice, even when they seem healthy, and their life expectancies were similar to those of the control group, they have different DNA codes than those bred traditionally.
The mice born from the parthenogenetic experiment had different epigenetic signatures in their DNA, which could lead to developmental processes. Epigenetic signatures are chemical modifications that are made to a DNA code but not directly to it. Instead, the changes happen outside the DNA “data.” Researchers concluded that these modifications could cause developmental destination.
Perry said he hopes to study the potential for skin cells to replace eggs in future works. As experiments continue, reproduction techniques using parthenogenotes and sperm could be the solution to endangered species and the opportunity for couples of the same sex to have children without the egg of another person.