Magic embryology: control over placental growth (Introduction)

by David Turell , Monday, June 13, 2022, 19:42 (894 days ago) @ David Turell

One specific protein is involved:

https://phys.org/news/2022-06-black-embryonic.html

:DNA regulation is a critical process in a cell that allows it to fulfill its function. This process is key during pregnancy, when embryonic cells must develop into all cell types needed to form an embryo. An international team of researchers from KU Leuven, Babraham Institute, Radboud University, Ghent University and IMBA, have discovered that the first cell fate decision of embryonic development is regulated by a protein known as PRC2. This new insight into human development could help us to understand early pregnancy loss in the future.

"All human beings start their existence as a sperm cell and egg cell. By the fifth or sixth day, the fertilized egg has become a blastocyst, a rapidly dividing cluster of cells, consisting of an inner and outer group of cells. The outer group will form the placenta; the inner cells will develop into an embryo. This development is a complex process whereby every step is critical, and the slightest mistake may end embryonic development.

***

"As early embryonic cells eventually form all cells, researchers have always assumed that early embryonic cells could easily switch genes on and off during development. "The first decision that cells need to take during human embryonic development is if they will form the embryo itself or the placenta. Our results show that this first decision is not as easy as we first thought," explains Professor Vincent Pasque (KU Leuven). "To form the placenta, the outer cells of the blastocyst must turn the correct switches on at the right time. We discovered that cells need to overcome barriers to turn placenta genes on," adds Hendrik Marks, group leader from Radboud University.

***

"'Using this embryo model, we could see that when we remove the protein PRC2, an increased number of placenta cells are present in blastoids. These results show that PRC2 is a barrier for the placenta cells to appear," explains Ph.D. researcher Irene Talon (KU Leuven).

"'Our research opens up the ability to better control stem cell specialization and blastoid development, which is useful for studying in the laboratory how the initial placental cells are formed. In the longer term, the new knowledge might improve our understanding of how embryos successfully implant in the uterus at the earliest stages of pregnancy, and why this can sometimes go wrong," concludes Professor Peter Rugg-Gunn."

Comment: one small step in understanding embryo developemnt automatic controls. How many controlled steps yet to find?