They discover mechanisms of contraction of cells that form human embryos

Paris. A group of researchers has revealed the mechanisms by which the first cells amalgamate to form embryos, a discovery that sheds new light on the first stages of human life.

Its about first analysis on the mechanics of human embryo morphogenesissummarizes the work, published in the magazine Nature.

A few days after fertilization, when the encounter between the sperm and the egg has already given rise to a stem cell, which has divided into about 10 more, these come together and agglutinate to form a single unit: the embryo in its earliest phase.

Only after that moment will the cells differentiate, gradually giving rise to organs and then to a human form.

Hallazgo crucial

This first stage, called compaction, it’s crucial. It is the subject of this study, carried out mainly by Julie Firmin, in which the French National Center for Scientific Research, the National Institute for Health and Medicine Research and the Curie Institute participated.

Until now, it was thought that the main mechanism of embryo formation was that by which cells stick together through the adhesion of their walls. However, according to research, this factor only plays a secondary role.

The most crucial thing is the contraction capacity of each cell, the mechanism by which they pull towards each other. You have to imagine a circle of people holding hands which is closing little by little, explains researcher Jean-Léon Maître, supervisor of the analysis, to AFP.

To reach this conclusion, the cells of several embryos left over from fertilizations were examined. in vitro and frozen in different phases between three and five days. The more advanced its state, the greater the contraction capacity of its cells, while the degree of adhesion of the walls remained stable. What makes cells stick to each other is not the amount of glue, but these contraction effortsMaster subrayed.

In the last 20 years, several works have revealed similar mechanisms in flies and mammals, such as mice, although the details vary between animal species and humans.

The new research allows us to better understand the human embryo, although very specific consequences cannot be expected immediately.

It is conceivable that this knowledge will one day facilitate the formation of embryos for fertilization in vitro.

Currently, the decision is made to implement some that have successfully passed this training phase.

The new analysis also marks an important advance in the knowledge of the beginning of human life, an area of ​​research that has accelerated in recent years, which also includes the recent production of embryo-like structures in the laboratory by several teams.

These structures, sometimes called synthetic embryos Although the term is controversial, they should allow us to study how cells and then organs differentiate during the first weeks of gestation.