Nature contains many different types of reproduction, ranging from sexual reproduction between males and females to asexual reproduction, in which a single organism is capable of generating progeny, such as spores, to a combination of both. The latter includes a type of reproduction known as partogenesis, in which a female is capable of producing offspring only through the use of her ovules, without the use of sex or the use of fertilized eggs. Certain fish, reptiles, amphibians, bees, scorpions, and mites reproduce in this manner, as do some other animals. Science has been attempting to artificially reproduce it in animals for quite some time (with the goal of applying it in disciplines such as research or medicine), but until recently it was thought to be impossible. Now, thanks to genetic manipulation, a group of Chinese scientists has successfully accomplished this feat in mice.

In the journal Proceedings of the National Academies of Sciences (PNAS), the researchers published their findings (PNAS).

The most significant barrier to this sort of reproduction in animals is a process known as genetic imprinting, which occurs when particular genes are expressed in a specific way depending on the sex of the parent who delivers them to the offspring. However, in order for an unfertilized egg to develop into an embryo, it must contain two sets of DNA, one from the egg's mother and the other from the egg's father. Furthermore, because the imprinting pattern is the same in both sets, some genes are unable to function properly or are turned off entirely.

Using two females as part of the process, Japanese researchers were able to produce a mouse in 2004. One of the eggs acted as if it had been supplied by Kaguya's 'father,' and the offspring was given the name Kaguya. This new procedure, on the other hand, has allowed for a conception that is almost 'virgin.' The research team at Shanghai Jiao Tong University in China succeeded in producing unfertilized mouse eggs with double the normal number of chromosomes by inserting DNA that is expelled early in the egg's development. Yanchang Wei and companions Following that, scientists employed the gene editing tool CRISPR to target seven imprinted gene areas that had previously been identified as being critical in embryo development and alter epigenetic imprinting, as previously reported. This resulted in the second copy of the mother's genetic code appearing as if it were that of a male, resulting in the ovum being tricked into developing into a viable embryo.

Wei and her team modified 227 unfertilized eggs, which resulted in the creation of 192 embryos in the process. Only 14 of these embryos made it to term, and of those, only three were still alive. One mouse eventually reached maturity and was able to procreate normally, while the other mice died. 'When compared to normal mouse pups, the living pups were underweight, and they also had specific genetic anomalies. This suggests that there are still imprinting regions involved in the development of the embryo that we do not fully understand, and that more research is needed "According to Tony Perry, a professor at the University of Bath (United Kingdom) who was not involved in the study, according to 'NewScientist' According to the researchers, "another possibility is that gene editing hasn't worked as well as it should."

It is unavoidable to consider the implications for human beings; nonetheless, while many scientists believe that this is a significant step forward in genome editing, it will be some time before a similar procedure is used to human newborns. "We know far less about imprinted genes in humans than we do about imprinted genes in mice," says Perry. "We know significantly less about imprinted genes in mice than we do about imprinted genes in humans." We are unable to conduct tests on them in the same manner that we can with mice."

CRISPR gene therapies are still considered to be "in their early stages," with the first human clinical trials testing cancer immunotherapy treatments for two common blood diseases (sickle cell anemia and beta -thalassemia), as well as for the deadly condition transthyretin amyloidosis, having taken place only recently (in 2015). While this is going on, there are dozens of studies that are awaiting approval before being tested on volunteers.