Serotonin, wnt are in charge of asymmetrical right-left development in embryos

Dec 16 2011

Spleen to the left, appendix to the right: In order for the body to sort itself out properly, two substances have to trigger a complex chain reaction, according to the latest findings at the University of Hohenheim. The international scientific journal Current Biology published the findings on dec. 15th under www.cell.com/current-biology/newarticles.

It's all a matter of communication: Studies with frogs have shown zoologists at the University of Hohenheim that two chemical messengers are responsible for cell communication in the embryo, a fact that was unknown until now. Only when these two substances cooperate do the heart, liver and spleen move into their correct positions. Both substances are also vital to the bodies of fully-grown adults.  A disturbance of their interplay could potentially lead to cancer. The international scientific journal Current Biology published the findings on dec. 15th under www.cell.com/current-biology/newarticles.

The chemical messenger serotonin is generally known as an endorphin, or "happy hormone". In fact, the substance actually is responsible for regulating many bodily functions, such as in the brain, the nerves in the stomach and the entire intestinal tract.  

A similar kind of multitalented chemical messenger is wnt. This substance is responsible for the development of the head-tail axis in frogs and for the growth of a fly's wings.   

Now a project team working under the auspices of Prof. Dr. Martin Blum, specialist for developmental biology, has found out that both of these substances are in charge of the asymmetrical right-left development in embryos. In the early stages of an embryo's development, they are partly in charge of the communication between cells and thus ensure that all organs find their way to their proper locations. 

The river that moves embryos

Serotonin and wnt trigger a rather complex process. After fertilisation, the egg cell begins and then continues to divide in symmetrical fashion. Even after only a few hours, serotonin and wnt command special cells to grow very fine hairs which rotate quickly, acting like a propeller.

This coordinated movement brings the fluid on the surface of the cells into motion, causing a determined flow from right to left.

It is this stimulus that activates the genes which are responsible for directing the body's organs to their proper location. This can only happen when both messengers, serotonin and wnt, are allowed to interact freely. "If one or the other is lacking, then the process doesn't even get started, resulting in defects in the embryo."

Possible starting point for new form of cancer treatment

Adults also seem to require the perfect and uninhibited interplay between serotonin and wnt. If this is not the case, then "cells divide which shouldn't divide", Prof. Dr. Blum explains. One possible result: cancer. 

This new discovery on the basic research level by scientists in Hohenheim might, therefore, be the starting point for new methods of treating cancer, a topic which the members of Prof. Dr. Blum's team want to explore in-depth with colleagues from the University of Heidelberg.