Scientists are one step closer to making 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 raises the prospect that older women could have children who share their DNA, and to 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 approve in humans, will also allow male couples to have genetically related children, as the men’s DNA can be combined in the fertilized egg and transferred through a surrogate mother can be carried.
“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,” said Aleksei Mikhalchenko, first author of the study. , said. at Oregon Health and Science University in Portland, USA. Gametes are sperm and egg cells.
Shoukhrat Mitalipov, a senior author of the study, said his lab has spent the past 20 years developing fertility treatments for patients who lack healthy sperm or eggs. Existing options, he said, forced people to use donated sperm or eggs and have genetically unrelated children. “Our technology will enable 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 various approaches to create eggs and sperm in the laboratory. Last year, Japanese researchers created eggs from the skin cells of male mice, which led to the birth of mouse puppies with two fathers. Other teams hope to create sperm and eggs from embryonic stem cellswhich is versatile enough to form any tissue in the body.
While many countries, including the UK, ban the use of artificial sperm and eggs to treat infertile couples, advances in the coming years could fuel calls to allow the procedures if they are deemed safe and effective.
The latest experiments, published in Science Advances, was 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 into the nucleus from a mouse skin cell. The egg is then cultivated in such a way that it naturally discards half of its chromosomes. This important step ensures that the egg contains the correct number of chromosomes – half from each parent – once it is fertilized by a sperm. “Eggs can be made by our approach in a matter of two to three hours,” 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 at the Roslin Institute in Edinburgh extracted the nucleus from a mammary gland cell of a Finn Dorset ewe and fused it with an egg, producing an embryo that carried all of the ewe’s DNA.
Mitalipov’s team has in 2022 the birth of three live mice of their experiments, but the success rate was less than 1%. Their latest study focuses on how the eggs discard half of their chromosomes, which are necessary for them to develop into a healthy embryo. “Our current goal is to improve the success rate at every stage of the process,” Mitalipov said.
Paula Amato, a professor of obstetrics and gynecology and a co-author of the study, said the advantage of the team’s technique is that it avoids the long culture times used by other approaches that reprogram cells. “Over a few months, many harmful genetic and epigenetic changes can occur,” she said.
“While the clinical applications of this technology may still be a decade away and will require thorough evaluation of safety, efficacy, and ethical aspects, its potential to address fertility-related issues offers promising prospects for future reproductive medicine,” Mikhalchenko said. added.
