Artificial Human Embryo from Human Skin Cells: A Pair of Studies Spoils Common Belief About Life's Beginning

A week ago, a pair of studies published in Nature spoiled the common belief of the beginning of life--- specifically the stages of a developing human embryo.

A SingularityHub article specified that it is common knowledge that human reproduction works this way: sperm meets egg, then fertilized eggs are kicking off its journey, transforming into a human embryo, then, eventually turning out as a fetus, and ultimately, a baby.

Two independent groups coaxed ordinary skin cells into a living cluster resembling a fertilized human egg and the initial stages of a developing human embryo.

But, as asked in the article, what if 'boy meets girl' is not the only way?

The research teams did not engineer an artificial embryo that could develop into a 'feasible' baby to get some clarification.

ALSO READ: Human Egg Cells Can Get Picky Over Which Sperm Gets to Penetrate Them: Study

The 'Blastocyst' Stage

They simulated what's occurring during the initial four days following an egg's fertilization. It then develops into a ball of eggs, also known as a blastocyst, the first towards a completely formed baby.

Even though they did not go beyond the blastocyst stage, both prototypes are, by far, the most complete models of an early human embryo today.

They don't just consist of cells growing into a baby, but all of the supporting structures, as well. Within only 10 days, like a Jello-like incubator inside, the reverse-engineered cells exhibited characteristics surprisingly akin to their natural counterparts.

For example, the artificial embryos generated cells that form the placenta, which is critical for a viable embryo that could theoretically develop further or even until birth.

The University of Michigan's Dr. Jianping Fu said this is the human early embryo's first complete prototype. Dr. Fu, who was not part of the study but wrote an accompanying perspective article, added an essential milestone.

Mysteries of Human Development

The studies suggest a new window into the initial days of pregnancy and may offer understanding into formerly mysterious infertility or pregnancy loss minus investigating human embryos.

Yet, these cells' sophistication is raising apprehensions. For now, since artificial embryos differ from natural ones in many ways, scientists are not expecting them to have the capability of growing into full-blown embryos.

As the technologies refine further, nevertheless, it may turn out to be possible to develop artificial human embryos for longer periods, positioning technology on a collision course with a database about life's beginning.

The first 14 days of building a human are said to be a mystery. Researchers are aware that a fertilized egg is developing into a blastocyst by the fourth day during pregnancy, and it then implants roughly on the eighth day.

By this time, what's described as something 'magical' happens within a blastocyst, such that it tosses out cells, eventually developing into the placenta, as well as others giving rise to a fetus.

How It's Done

The pair of studies represent the first time researchers have developed blastocyst-like structures from human cells.

In one of the studies, Monash University's Dr. Jose Polo started with a formerly published recipe. Here, skin cells gently scraped off and bathed in a chemical soup that goes back to them to a stem cell-like condition. This means that they are regaining the ability to make other types of cells.

From there, iPSCs or pseudo stem cells are cleansed in what's described as a nutritious liquid in a Petri dish. The team's spark of insight came when they realized that after three weeks, the cell began branching out into a potpourri of three different types of cells found in early human embryos, something unusually observed in the past.

Inspired, the research team then transferred the cells into a 3D jello-like culture system for support. Oddly, the cells started to self-assemble with a mind of their own.

What was completely shocking, explained Polo, is that they are self-organizing when they are put together. The strange cells are assembling, a moment that prompted the team to assess their genetics.

To the scientists' surprise, they discovered that these early embryo-like structures, called 'iBlastoids,' had the same organization and component of cells as their natural counterparts.

Related information is shown on California Center for Reproductive Medicine - CACRM's YouTube video below: