This breakthrough could have significant implications for same-sex couples looking to have biological children.
Japanese scientists have created a mice with two biological fathers, according to a report from The Guardian. This breakthrough could have significant implications for same-sex couples looking to have biological children. Additionally, the technique may also be useful in treating severe forms of infertility, including Turner’s syndrome, a condition where one copy of the X chromosome is missing or partially missing, which was the primary motivation of the research, according to the scientists.
“This is the first case of making robust mammal oocytes from male cells,” said Katsuhiko Hayashi, who led the work at Kyushu University in Japan.
While scientists have previously used complex genetic engineering techniques to create mice with two biological fathers, a significant headway has now been achieved. For the first time, viable eggs have been successfully cultivated from male cells, making the process less complicated and more accessible.
Process of the birth
In order to produce viable eggs from male cells, the study required a series of complex procedures. The first step involved reprogramming male skin cells into a state similar to that of stem cells, known as induced pluripotent stem (iPS) cells.
The Y chromosome of these cells was then removed, and an X chromosome from another cell was inserted, resulting in iPS cells that possessed two identical X chromosomes. This technique allowed the researchers to create viable eggs with an XX chromosome combination, despite starting with male XY cells.
“The trick of this, the biggest trick, is the duplication of the X chromosome,” said Hayashi. “We really tried to establish a system to duplicate the X chromosome.”
After undergoing the complex process of transforming male skin cells into viable eggs, the cells were grown in a specialized culture system called an ovary organoid. This system was designed to mimic the conditions present in a mouse ovary. When the eggs were fertilized with normal sperm, the researchers were able to obtain approximately 600 embryos, which were then implanted into surrogate mice.
This resulted in the successful birth of seven mouse pups. However, the efficiency of the process was found to be lower than that achieved using normal female-derived eggs, with only around 1% of the embryos resulting in a live birth compared to around 5% with traditional eggs.
Possible with humans?
The study noted that human cells require longer periods of cultivation to produce a mature egg, which can increase the risk of acquiring unwanted genetic changes. The translation of this technique to human cells would require a substantial leap in research, especially considering that scientists are still working to create lab-grown human eggs from female cells.
Professor Amander Clark of the University of California, Los Angeles, who works on lab-grown gametes, said that translating the work into human cells would be a “huge leap” because scientists have yet to create lab-grown human eggs from female cells.
Scientists have created human egg precursors, but the cells have stopped developing before meiosis, a critical step in cell division required for the development of mature eggs and sperm.“We’re poised at this bottleneck at the moment,” Clark said
She stressed that the next steps are an engineering challenge and getting through that could be 10 years or 20 years.
Source : Hindustantimes