Scientists create human eggs via in vitro gametogenesis : NPR

This image shows a human egg after its original DNA has been replaced by the DNA of an adult skin cell.

Mitalipov laboratory

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Mitalipov laboratory

Scientists have created human eggs containing genes from adult skin cells, a step that could one day help infertile women or homosexual couples have babies with their own genes, but also raised difficult ethical, social and legal problems.

“It’s an important step forward,” said Shoukhrat Mitalipov from Oregon Health & Science University in Portland, which led the research published in the journal Nature communications.

Millions of women cannot have children using their own eggs because of their age or other reasons. Scientists have therefore tried to create human eggs in the laboratory that carry the genes of people who find it difficult to have children. The field is known as Gametogenesis in vitro and involves researchers from around the world, including in Japan, as well as in American biotechnology companies.

“This technology would allow many of these women to genetically have their own eggs and have a genetically linked child,” said Mitalipov.

Mitalipov and his colleagues used a technique different from most researchers who pursue this goal.

The most common approach consists in converting adult cells, such as skin or blood, into cells known as induced or IPS pluripotent cells. Scientists then tried to coax these IPS cells by becoming eggs or sperm. The closest whoever succeeded in eggs was very primitive human egg cells which are too immature to be fertilized.

The Mitalipov team has used the technique that was used to clone Dolly the sheep: scientists have removed most of the DNA from a healthy donor egg and replaced it with most DNA from another woman’s skin cell.

Then, the researchers essentially deceived the reconstituted egg to jump normal forms of cell division known as mitosis and meiosis. Instead, they have pulled the eggs to go through a different process that they nicknamed “Mitomeiosis”. This produced 82 functional eggs, the researchers reported.

Scientists then fertilized the eggs with sperm to see if they could turn into embryos. And that seems to have worked, at least in a small number of tests, report the researchers. Nine percent of the resulting embryos have been developed at the blastocyst stage, that is to say when the embryos would be transferred to a woman’s uterus, the researchers reported.

Delicate problems with promising technology

However, none of the embryos would have been adapted to the establishment in a uterus to develop more. Indeed, all embryos still had genetic anomalies that would prevent healthy development.

Mitalipov, however, hopes that he will end up solving this problem. And other scientists aggressively pursue other approaches to achieve the same objective.

Some other scientists have praised the new research.

“I think this is a very significant step in terms of passing to the ability to use skin cells to make egg cells for human reproduction at one point in the future, once we can prove that this is safe and effective,” explains Dr. Sigal Klipstin, an endocrinologist reproduced by the American Society of Reproductive Medicine. “Proof of concept is fascinating.”

If Ivg is never perfected, technology could have applications beyond helping infertile women. Abortion could, for example, allow gay couples to have babies genetically linked to both partners. Scientists could create eggs from a skin cell from a male partner and fertilize it with sperm from the other male partner.

“The implications are enormous,” says Mitalipov.

But some scientists warn that genetic anomalies in Mitalipov’s embryos raise questions to find out if this approach could ever work.

“It is not clear if skipping meiosis in half of the genome is compatible with human development,” said Amander Clark, professor of molecular biology and development at the University of California in Los Angeles. “Time and more fundamental research will say.”

Ethical concerns abound

And even if it worked, technology would create a lot of delicate problems. Some fear that this can help create “baby babies”, where parents can choose the features of their children.

“We could see more efforts to try to use it for so -called improvement purposes – to try to obtain embryos that would be stronger or more athletic or more musical or better in mathematics or more intelligent,” explains Hank Greely, a Bioethician from the University of Stanford who wrote who wrote The end of sex and the future of human reproduction. “Some people consider it a terrible perspective. Some people consider it a wonderful perspective.”

Another concern is that it could allow people to steal a skin cell to another person, such as a celebrity, and to make a baby with their DNA without their knowledge or their authorization.

“We could have babies Taylor Swift all over the world. It is a theoretical possibility, but not crazy,” explains Ronald Green, bioethicist of the Dartmouth College. “It is a very promising technology. But it raises a number of intimidating ethical questions.”

Another possibility is to use this technology to create a “uni-baby”, a child containing only the genetic equipment of a single person.

“It’s a very strange possibility,” explains Greely. “Anyone would like to do that? Well, there are 8 billion people around the world and some of them have very strong Egos and some are very rich. I therefore do not guarantee that no one would like to do that.”

Although all these possibilities must be debated, Greely and others maintain that technology deserves to be monitored.

“If he was sure, that would offer relief to millions of people around the world who desperately want to have children who are genetically theirs,” said Greely.