Scientists are getting closer to making IVF eggs from skin cells

Scientists are one step closer to creating IVF eggs from patients’ skin cells after adapting the procedure that created Dolly the sheep, the first cloned mammal, more than two decades ago.

The work offers the possibility that older women could have children who share their DNA, and overcome common forms of infertility caused by a woman’s eggs being damaged by disease or cancer treatment.

The radical procedure, which could take a decade to perfect and adopt in humans, would also allow male couples to have genetically related children because the man’s DNA could be combined in the fertilized egg and delivered by a surrogate mother. can be accomplished.

“Should this technology become clinically viable in the future, it has the potential to revolutionize IVF and offer hope to many infertile patients who have lost gametes due to disease, aging or cancer treatments,” says Aleksei Mikhalchenko, the first author of the study. at Oregon Health and Science University in Portland, USA. Gametes are sperm and egg cells.

Shoukhrat Mitalipov, a senior author of the study, said that over the past two decades his laboratory has developed fertility treatments for patients who do not have healthy sperm or eggs. The existing options, he said, forced people to use donated sperm or eggs and have genetically unrelated children. “Our technology would allow infertile patients to have genetically related children, providing a path to parenthood that is currently unavailable even with IVF,” he said.

Scientists around the world are working on different ways to create eggs and sperm in the laboratory. Last year, Japanese researchers created eggs from the skin cells of male mice, leading to the birth of mouse pups with two fathers. Other teams hope to create sperm and eggs from embryonic stem cells, which are versatile enough to form any tissue in the body.

While many countries, including Britain, are banning the use of artificial sperm and eggs in the treatment of infertile couples, developments in coming years could prompt calls to allow the procedures if they are deemed safe and effective .

The latest experiments, published in Science Advances, were performed in mice and took a different, much faster approach to creating IVF eggs. The researchers start with a donor egg and remove its nucleus. They are then transferred to the nucleus of a mouse skin cell. The egg is then grown so that it naturally discards half of its chromosomes. This crucial step ensures that the egg contains the correct number of chromosomes – half from each parent – ​​once it is fertilized with a sperm. “Eggs can be made in two to three hours using our approach,” Mikhalchenko said.

Dolly the sheep was created in 1996 through a similar process known as somatic cell nuclear transfer, or SCNT. Prof. Ian Wilmut and his team from the Roslin Institute in Edinburgh extracted the nucleus from a mammary gland cell from a Finn Dorset ewe and fused it with an egg, creating an embryo that carried all of the ewe’s DNA.

Mitalipov’s team announced the birth of 2022 three live mice of their experiments, but the success rate was less than 1%. Their latest research focuses on how the eggs throw away half of their chromosomes, which is necessary to develop into a healthy embryo. “Our current goal is to increase the success rate at every stage of the process,” said Mitalipov.

Paula Amato, professor of obstetrics and gynecology, and co-author of the study, said the advantage of the team’s technique was that it avoided the long culture times used by other approaches that reprogram cells. “Many harmful genetic and epigenetic changes can take place over several months,” she said.

“Although the clinical applications of this technology may still be a decade away and will require thorough evaluation of its safety, efficacy and ethical aspects, its potential to address fertility-related issues offers promising prospects for future reproductive medicine, ” added Mikhalchenko.