Baby Without Sperm Or Egg? Scientists Develop Synthetic Embryos Using Stem Cells

International

oi-Prakash KL

In a major development that has stunned the medical field, a team of researchers in the USA and UK have, for the first time, created synthetic human embryos using stem cells.

These model embryos offer valuable insights into the effects of genetic disorders and the biological factors contributing to repeated miscarriages, scientists say.

The artificial embryos lack a functioning heart or brain, but they consist of cells responsible for forming the placenta, yolk sac, and embryo. Currently, there are no immediate plans to use these synthetic embryos in clinical settings, and it is against the law to implant them into a patient’s womb. It remains uncertain whether these structures possess the ability to progress further in development beyond the initial stages.

However, this research is yet to be published in a journal and the research was first reported by The Guardian.

“We can create human embryo-like models by the reprogramming of [embryonic stem] cells,” Aljazeera quoted Professor Magdalena Zernicka-Goetz, of the University of Cambridge and the California Institute of Technology, as saying in an address on Wednesday at the International Society for Stem Cell Research annual meeting in Boston.

It also raises legal and ethical questions, even as many countries currently lack regulations looking at the creation and manipulation of synthetic embryos.

“Unlike human embryos arising from in vitro fertilisation (IVF), where there is an established legal framework, there are currently no clear regulations governing stem cell-derived models of human embryos. There is an urgent need for regulations to provide a framework for the creation and use of stem cell-derived models of human embryos,” CNN reported James Briscoe, associate research director at the Francis Crick Institute, saying in a statement.

Zernicka-Goetz and her research team, alongside a competing team in Israel, had previously documented the generation of model embryo-like structures using mouse stem cells. These “embryoids” exhibited the early formations of a brain, heart, and intestinal tract after approximately eight days of growth.

The embryo-like structures were grown from single human embryonic stem cells, Zernicka-Goetz stated and that was coaxed to develop into three distinct tissue layers. She also pointed out that the structures were first to have germ cells that would go on to develop into egg and sperm. “I just wish to stress that they are not human embryos,” Zernicka-Goetz said.

She continued, “They are embryo models, but they are very exciting because they are very looking similar to human embryos and very important path towards discovery of why so many pregnancies fail, as the majority of the pregnancies fail around the time of the development at which we build these embryo-like structures.”

As per her knowledge, it was the first time a human model embryo had been created with three tissue layers.

Currently, the synthetic model human embryos are limited to laboratory test tubes. Implanting them into a womb would be deemed illegal, and previous attempts using stem cells from mice and monkeys in animal research have demonstrated their inability to survive. This outcome is likely attributed to the incomplete replication of pregnancy conditions, indicating that researchers have yet to fully comprehend the intricacies involved.

Zernicka-Goetz claims that the aim of her research wasn’t to create life but to prevent its loss. “We know remarkably little about this step in human development, but it is a time where many pregnancies are lost, especially in an IVF setting,” Roger Sturmey, senior research fellow in maternal and fetal health at the University of Manchester in the UK, said in a statement.

“Currently, we can say that these ‘synthetic embryos’ share a number of features with blastocysts, but it is important to recognise that the way that synthetic embryos are formed is different to what happens when a normal embryo forms a blastocyst,” he added.

Sturmey claims that much work needs to be done to determine the similarities and differences between synthetic embryos and embryos that form from “the union of an egg and a sperm.”

Story first published: Thursday, June 15, 2023, 21:18 [IST]