Rat embryo with beating heart was cultured entirely in a Petri dish.

Few things in the world are more incredible than pregnancy. It doesn’t matter if it’s a human mommy or any other kind of animal. The animal kingdom is more curious than the human. This is because of the diversity of species. However, even though some characteristics are different between animal and human species, one thing in common is that the embryo develops in the uterus until the moment of its birth.

However, recently, scientists have managed to create the most complex life forms ever developed in Petri dishes. They can pump blood through tiny beating hearts, and scholars have gradually increased nerves and muscles in a laboratory.

The small collections of mammalian cells were rudimentary mouse embryos . They were built from scratch from stem cells, which have the potential to grow any other type of cell in the body.


While for some time scientists have been able to successfully create synthetic organs called organoids, they don’t have many of the cell types that are found in real organs. This constructed mouse embryo is much more complex.

“Watching an embryo develop is a wonderful thing to see.

The embryoid is not a complete mouse and cannot fully develop because it still lacks key parts, such as a giant piece of the brain. However, the complexity of this experiment made the researchers take a big step towards being able to build fully functional organs in the laboratory.


“Human organs are made up of various types of cells that originate from different parts of the growing embryo. The intestine, for example, is made up of cells that form a hollow tube. Models of this tube in a dish have already been made and are called intestinal organoids,” said developmental biologist Bernard Thisse.

“However, this tube is not enough to make a functioning intestine because this organ contains other components, such as smooth muscles, blood vessels and nerves that control the function of the intestine and which are made up of cells from different origins. The only way to have the full range of cells necessary for the formation of functional organs is to develop systems in which all the precursor cells are present. The embryo-like entities we’ve created using stem cells are providing just that,” he continued.

For these fully functioning biological systems to be created, a number of things need to be right. For example, the right cell type, spatial location and timing of cell signals to achieve the desired result. Recreating these processes is possible because of the generations of research in biology that are underway. Including the team’s own previous research on zebrafish.


This most recent work by the team has resulted in these mouse embryos working miraculously, with all the layers of normal embryonic tissue. In addition, the cells and tissues were correctly organized around the embryoid spinal cord precursor.

However, the embryoid still lacks parts of the brain. The team suspects that this may be because the chemical signal that tells cells they are at the far end has spread too far.

“With the techniques we’ve developed, we should be able, at some point, to manipulate the molecular signals that control embryo formation, and this should lead to the generation of embryo-like entities containing all tissues and organs, including the forebrain” , ponders Bernard Thisse.

The researchers’ goal is to be able to learn how to fully control and manipulate the development of the embryo. And they believe this can be a very powerful tool for studying disease.

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