On Wednesday, scientists announced they have transformed human skin cells into eggs and successfully fertilized them with sperm in a laboratory setting for the first time. This groundbreaking achievement holds the potential to enable infertile individuals to have children in the future.
The technology is still several years away from being accessible to potential parents, according to the team of US-led scientists.
External experts believe this pioneering research could redefine infertility, which affects one in six people globally.
If proven successful, the technology known as in-vitro gametogenesis (IVG) could allow older women or those lacking eggs for various reasons to reproduce genetically, explained Paula Amato, co-author of the study. She shared this insight with AFP.
“It could also enable same-sex couples to have a child genetically linked to both partners,” added Amato, a researcher at Oregon Health & Science University in the US.
Significant strides have been made in this field recently, with Japanese scientists revealing in July that they created mice with two biological fathers.
The latest study, featured in the journal Nature Communications, represents a major leap forward by utilizing human DNA instead of that from mice.
Initially, scientists removed the nucleus from standard skin cells and inserted them into a donor egg with its nucleus extracted. This process, known as somatic cell nuclear transfer, was famously used to clone Dolly the sheep in 1996.
However, a challenge remained: skin cells contain 46 chromosomes, whereas eggs have 23.
Researchers successfully removed the extra chromosomes through a method they termed “mitomeiosis,” which emulates the natural cell division process.
They generated 82 developing eggs, referred to as oocytes, and fertilized them with sperm using in vitro fertilization (IVF).
After six days, fewer than nine percent of the embryos developed to a stage where they could theoretically be transferred to the uterus for a conventional IVF procedure.
Despite this, the embryos exhibited various abnormalities, leading to the experiment’s conclusion.
Although the nine-percent success rate was low, researchers highlighted that only about one-third of embryos reach the IVF-ready “blastocyst” stage during natural reproduction.
Amato estimated that the technology is at least a decade away from becoming widely available.
“The main challenge is producing genetically normal eggs with the correct number and structure of chromosomes,” she stated.
– Breakthrough –
Ying Cheong, a reproductive medicine researcher at the University of Southampton in the UK, praised the “exciting” breakthrough.
“For the first time, scientists demonstrated that DNA from normal body cells can be inserted into an egg, activated, and prompted to halve its chromosomes, imitating the unique steps that naturally generate eggs and sperm,” she remarked.
“Although this remains early-stage lab work, it could revolutionize our understanding of infertility and miscarriage in the future, potentially paving the way to create egg- or sperm-like cells for those with no other options,” she added.
Other researchers aim to create lab-grown eggs using a different approach. This involves reprogramming skin cells into induced pluripotent stem cells, which can develop into any cell type, and then turning them into eggs.
“It’s too soon to determine which method will prove more successful,” Amato commented. “Regardless, we are still years away.”
The researchers adhered to existing US ethical guidelines governing embryo use, as noted in the study.
