3D blastocystOne of life’s most endearing moments occurs when a new parent gives a first hug to a newborn baby. Countless medical studies have documented the nurturing value of the human touch. New research indicates the most important hug of all may be performed by the developing embryo itself, when it’s only eight cells big. This one act may also become instrumental in determining which embryos are the best candidates for in vitro fertilization (IVF) implantation.

This embryonic hug is described as “a completely unanticipated mechanism” by Dr. Nicolas Plachta, one member of a three-person team of researchers using live imaging technology and fluorescent markers to track changes made in mice embryos. Plachta’s research team at the Monash University Australian Regenerative Medicine Institute (ARMI) in Melbourne includes Dr. Melanie White and Dr. Juan Carlos Fierro-Gonzalez.

The Monash research team watched as an embryo divided until eight cells were created. They expected to see cellular division continue as before but were surprised to see microscopic arm-like structures called filopodia reach out from the eight cells, grab hold of the adjacent cells, and squeeze until the eight round cells became elongated and densely compacted against each other. After this group hug, the filopodia retreated back into the cells and cellular division resumed. No cellular division occurred as the filopodia squeeze was in progress.

Furthermore, embryos that did not undergo this hug and subsequent compaction were less likely to survive.

Plachta said, “We can apply that knowledge to human IVF treatments.” The researchers are already working on ways to watch mouse embryos divide and develop in real time and are working with the Monash School of Engineering to develop ways the process can be used to improve the rate of successful embryo implants in humans.

By using non-invasive imaging methods to watch human embryonic filopodia form, squeeze, and compact the cells, fertility specialists in the future may have the means to determine which embryos would be most successfully implanted.

The findings of the Monash study are published online and in the print version of the medical journal, Nature Cell Biology.

Source: Fierro-Gonzales, Juan Carlos, et al. “Cadherin-dependent filopodia control preimplantation embryo compaction (abstract).” Nature Cell Biology. Nature Publishing Group / Macmillan Publishers Limited. Nov 24, 2013. Web. Dec 18, 2013.