Embryos become "independent" at an early stage of development

When does a human embryo stop using genes from the ovule and spermatozoid and instead use its own? Scientists with the IRB Barcelona Functional Genomics Platform, headed by Herbert Auer, in collaboration with researchers at the Center of Regenerative Medicine in Barcelona (CMRB), have revealed the genetic program of human embryos that is activated early in development when embryos comprise only two cells. The results of this study have been published in the most recent issue of the journal Development.

One of the limitations of embryo research is the difficulty to obtain sufficient amounts of biological material. To overcome this problem, the scientists have used the “Pico Profiling” method, developed by Auer and published recently in the journal PLoS ONE, to study in a reliable manner the genetic activity of individual embryos formed by only a few cells.

Contrasting with what has commonly been believed for the last thirty years, the results of this study demonstrate the embryos activate their genetic program when they are formed by only two cells. From this point onwards, embryos also activate stem cells, which later go on to form the organs and tissues of the late embryo.

“These results may have important implications in biomedicine because they may contribute to the development of new markers that allow a better selection of embryos fertilized “in vitro”. Furthermore, these findings suggest that research on embryonic stem cell development should be performed at very early stages before these cells appear in the embryo”, added Rita Vassena, first author of the article.

Reference article:
Waves of early transcriptional activation and pluripotency program initiation during human preimplantation development.
Rita Vassena, Stéphanie Boué, Eva González-Roca, Begoña Aran, Herbert Auer, Anna Veiga and Juan Carlos Izpisua Belmonte.
Development (2011). [doi:10.1242/dev.064741]