During embryonal development of vertebrates, signaling molecules inform each cell at what position it is located. In this way, the cell can develop its special structure and function. For the first time now, researchers of Karlsruhe Institute of Technology (KIT) have shown that these signaling molecules are transmitted in bundles via long filamentary cell projections. Studies of zebrafish by the scientists of the European Zebrafish Resource Center (EZRC) of KIT revealed how the transport of the signaling molecules influences signaling properties. An article published online on January 5, 2015 in the Nature Communications journal presents the results. Organisms, organs, and tissues are complex three-dimensional systems that consist of thousands of cells of various types. During embryonal development of vertebrates, each cell requires information on the position at which it is located in the tissue. This position information enables the cell to develop a certain cell type for later execution of the correct function. This information is transmitted via signaling molecules, so-called morphogens. These morphogens are not homogeneously distributed in the tissue; their concentration varies. Various concentrations activate various genes in the target cell. The cells in the developing central nervous system receive their position information from signal molecules belonging to the family of Wnt proteins. The concentration of Wnt proteins determines whether a cell differentiates to a cell of the forebrain or of the afterbrain. “Distribution of these signal molecules has to be controlled precisely,” Dr. Steffen Scholpp, head of a research group of the KIT Institute of Toxicology and Genetics (ITG), explains.Login Or Register To Read Full Story