Embryology: very premature cellular differentiation

A study published in the journal Cell shows that the differentiation of embryo cells begins very early in the development. Already at the stage of 4 cells, the second day following conception, differences can be observed according to Cell sources, researchers at the Physiology, Development and Neurosciences Department of Cambridge University.

The experiment was carried out on mouse embryos by using DNA screening and sequencing techniques. The researchers compared the activity of certain genes in each cell and were able to show different behavior for some of them, thus predisposing certain cells to produce embryonic extensions, such as the placenta for example.

For Cambridge professor, Magdalena Zernicka-Goetz, “Life begins when a sperm cell goes into the ovum, but it is interesting to know when the major determining decisions for our future development take place. We now know that from the early embryonic stage of 4 cells – only two days after conception – the embryo is guided in a particular direction and its cells aren’t already identical anymore.”

But what actually activates cellular differentiation is another mystery, as specifies Janet Rossant from the University of Toronto.

Cambridge researchers are trying to solve this mystery. They wish to improve knowledge in the use of stem cells to make body tissues and organs for regenerative medicine. For Zernicka-Goetz, these studies could also be useful for recognizing the most viable embryos during embryo culture phases in the context of in vitro fertilizations.