Scientists in Oregon have taken a significant step toward developing lab-grown eggs and sperm to one day help people conceive, by using human skin cells to create fertilisable eggs.
The experiment, conducted by a team at Oregon Health and Science University (OHSU), revealed chromosome abnormalities in the resulting cells. This prompted the researchers to caution that it could take a decade of additional research before such a technique is ready for trials in people. The work, which was published in Nature Communications on Tuesday, offers valuable lessons as scientists pursue ways to create eggs and sperm in a lab—a goal that could aid the infertile or help same-sex couples have children genetically related to both partners.
The experimental process and challenges
The OHSU team began by removing the nucleus from a human egg cell and replacing it with the nucleus from a human skin cell. A skin cell contains two sets of chromosomes, while eggs and sperm are each meant to contain only one set that combines during fertilisation. The researchers therefore had to induce the egg-like cells to discard extra chromosomes. They then injected donated sperm and jumpstarted post-fertilisation development.
Approximately 9 per cent of the cells lasted for six days in lab dishes, reaching the blastocyst stage of early embryo development before the experiment was halted.
The main issue, however, was that the resulting cells showed multiple chromosome abnormalities.
"We kind of developed this new cell division that can reduce chromosome number," explained Shoukhrat Mitalipov, the study's senior author and OHSU's embryonic cell and gene therapy director. "It's still not good enough to make embryos or eggs genetically normal". He described the initial findings as a proof-of-concept and stated that his team is actively working on improvements.
Expert reaction
Scientists not involved in the work had mixed reactions. Dietrich Egli, a stem cell researcher at Columbia University, expressed concern about the abnormalities. However, Dr. Eve Feinberg agreed that the chromosome problems were critical but said it "seems like this team figured out how to reduce the number, just not well yet. But it's an important step and very exciting".
ALSO READ: Google Gemini AI image prompts for girls: Top prompts to create unique images with sports car
