Figure 5: Diagram showing how ES cells communicate with trophoblasts to promote embryo implantation.

In the blastocyst stage embryo, the ES cells reside in the ICM and are surrounded by trophoblasts (left image). While it is known that the trophoblasts in the blastocyst respond to signals emanating from the mother to migrate and invade into the uterus (implantation), we have discovered that ES cells also contribute to this process by generating MVs (right image). The MVs are capable of activating signalling events in trophoblasts that enhance their ability to migrate.