Researcher Finds ‘Head-to-Tail’ Axis Development Trigger in Human Embryo

During days seven and fourteen of the developing human embryo, one of the most secretive yet vital stages of our development, researchers have discovered significant chemical events.

An important period in the development or embryogenesis of the embryo occurs in the second week of pregnancy. One of the main causes of extremely early pregnancy loss is failure of development during this period. Knowing more about it will undoubtedly aid researchers in understanding how problems can arise and in taking activities to be able to fix issues.

The pre-implantation stage in human embryos has been thoroughly investigated in laboratory settings before the developing embryo embeds directly into the woman’s womb. The embryo must enter the womb by the seventh day in order to survive and grow. Since the human embryo cannot be studied once it embeds, very little is known about how it develops.

Researchers led by Professor Magdalena Zernicka-Goetz developed a method to culture human embryos outside of the female body after implantation, which was published in 2016. This made it possible to conduct the first-ever research on human embryos up to day 14 of growth.

The group recently worked with associates at the Wellcome Sanger Institute to reveal what transpires at the molecular level during this initial period of embryogenesis. Their findings provide the first concrete proof that the hypoblast, a collection of cells located external to the embryo, communicates with it in a way that triggers the formation of the head-to-tail body axis.

The embryo’s proportionate foundation begins to shift as the body axis develops. One end commits to growing into the head end, and the other throughout the “tail.”

Although significant changes in the location and structure of the cells, the new findings, which were published today in the journal Nature Communications, show that the molecular signals involved in the development of the body axis show parallels to those in mammals.

As the senior author of the study and Professor Magdalena Zernicka-Goetz at the University of Cambridge’s Department of Physiology, Development, and Neuroscience, she stated, “We have exposed the patterns of gene expression in the developing embryo after it implants in the womb, which show the numerous discussions taking place in between various cell kinds as the embryo develops through these early stages.”

“Ultimately, we were looking for the gene interaction that will certainly permit the head to start developing in the embryo and found that it was initiated by cells in the hypoblast, a disc of cells outside the embryo,” she continued. They communicate this to neighboring embryo cells, which respond by saying, “OK, just now we will separate to form the head conclusion.

Through the sequencing of the hundreds of messenger RNA molecules that each cell produces, the study was able to identify the gene debates occurring in the developing embryo. After implantation in the womb, they monitored the developing molecular profile of the developing embryo, revealing the increasing loss of pluripotency (the capacity of the embryonic cells to give rise to any type of cell of the future creature) as different cells’ fates are selected.

Our objective has always been to make it possible to appreciate the very early stages of human embryonic development in a dish and how our lives begin. We have delved further into the crucial changes that occur at this incredible stage of human development, when many pregnancies, however, fail, by fusing our brand-new technology with unique sequencing approaches,” stated Zernicka-Goetz.

Originally published on Phys.org. Read the original article.