2 min readNew Insight into the Development of the Central Nervous System of Vertebrates
Karlsruhe, Germany — During embryonal development of vertebrates, signalling molecules inform each cell at which 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 signalling molecules are transmitted in bundles via long filamentary cell projections. Studies of zebrafish of the scientists of the European Zebrafish Resource Center (EZRC) of KIT revealed how the transport of the signalling molecules influences signalling properties. A publication 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 signal molecules, so-called morphogenes. These morphogenes are not homogenously 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. “Smallest changes of the concentration or the transport direction may cause severe damage, such as massive malformations during embryonal development or formation of cancer.”
For the first time now, the working group of Dr. Steffen Scholpp has shown that the Wnt proteins are transmitted specifically via long cell projections, so-called filopodia. In the Nature Communications journal, the scientists report that the signalling factors are loaded on the tips of the filopodia only. In this way, signalling can start immediately upon contacting. The signalling factors bind to the corresponding receptors of the target cell and induce the correct cell response. “Now, the source cell can decide precisely which target cell receives how much signalling protein at which time,” Scholpp explains. The KIT researchers study zebrafish and human cell lines and succeeded in reproducing or reducing the filopodia and analyzing the resulting changes of signalling properties of the Wnt morphogenes.
Article adapted from a Karlsruher Institut für Technologie (KIT) news release.
Publication: Filopodia-based Wnt transport during vertebrate tissue patterning. Eliana Stanganello, Anja I.H. Hagemann, Benjamin Mattes, Claude Sinner, Dana Meyen, Sabrina Weber, Alexander Schug, Erez Raz & Steffen Scholpp. Nature Communications (January 05, 2015): Click here to view.