Female sperm, male eggs

After the Japanese scientists created eggs and sperm in the laboratory, experts are trying to find ways to use these cells safely.

Since October last year, molecular biologist Katsuhiko Hayashi of Kyoto University (Japan) has received countless letters from couples, mostly middle-aged, desperately looking forward to their children. A menopausal woman in England wanted to go to the specialist's laboratory in Tokyo in the hope that he would help her fulfill the only expectation: a child.

These requests were sent after Hayashi published a new study showing that in the future, male and female reproductive cells could be raised from different genders. In other words, it is easier to understand, scientists can create sperm from women and eggs from men. According to a report published by Scientific American, Katsuhiko Hayashi and Professor Mitinori Saitou of Kyoto University presented how to use mouse skin cells to form primitive germ cells of the sperm, or PGC .

Can make cells reproduce from skin cells - (Photo: Nature)

These cells, which are precursors to both male and female sex cells, are then developed into eggs and sperm. The results showed that the products produced in the process were still successfully used to create embryos in the experimental environment and the pups born through IVF.

Although related techniques are still in the early stages, experts highly appreciate the potential of application in the field of reproductive support. Hayashi's research not only allows infertile women to have babies by creating eggs from their skin cells, but also opens up the prospect of creating egg and sperm cells from men or women. This process begins by extracting pluripotent stem cells from early embryonic cells and somatic cells, then using 'signaling molecules' to turn them into PGC. The skin cells are transplanted into the ovaries and testes of mice to grow. Once they reach adulthood, they are removed and used in vitro fertilization.

The initial study took place in October 2012, and the pups born in this process were only 'side effects' to prove that the creation of PGCs was successful. Since then, scientists around the world have begun to realize the real potential of the study, and the team of researchers in the first study is evaluating the potential of human use. According to the Scientific American report, other researchers have repeated the PGC production process, but have not been able to create the final product as a living organism. Experts have encountered many obstacles in the process, including the risk of creating fragile and distorted eggs. However, the biggest challenge is to repeat the successful experiment in mice in case of people. This is because the signaling molecules used to create PGC in humans are much more complex than mice. In addition, access to human embryos is also limited by national laws.

Currently, a team of Japanese experts led by Saituou and Hayashi are using monkey embryos as a stepping stone when switching from rat studies to primates. Hayashi predicts that they can succeed with primates within 5 to 10 years, and the creation of human PGC will soon be deployed later. However, even if the process is successfully done in monkeys, there are still too many dangers that take years to analyze.

Experts have known that the original embryonic stem cells developed in the laboratory often gather many types of gene mutations and epigenetic abnormalities. Even if a healthy descendant has been created from this method, scientists still wonder how many generations to observe before concluding that the new technique is "safe" genetically.