Feb 15 2011
New and complex life can only develop if single cells in an organism know how to develop and which exact position to take.
This orientation is supported by a sort of cellular GPS system which transmits unambiguous information about their position and destiny. So far it could not be demonstrated how the cells analyze the information and react accordingly. For the first time, Dresden scientists were now able to monitor how cells interpret the tracking signals of a certain signal protein and make use of them for further development in a zebrafish.
During an organism’s development, different types of tissues unfold from only a handful of cells. For years have scientists been interested in decoding the fascinating processes that are vital for the evolution of life. Signal molecules determine in concentration gradients which sort of tissue develops from which cell and where exactly. However, this “cellular GPS system’s” signals need to be assessed by the cells in order to use this information purposefully. The molecular mechanisms behind this interpretation have remained mostly unclear. Now scientists from the DFG Center for Regenerative Therapies in Dresden and the Biotechnological Center at TU Dresden (BIOTEC) have shed some light on the issue with a study published in the Nature Cell Biology journal. In living zebrafish, they monitored how cells can change their formation and positioning by interpreting the tracking signal without changing the “GPS Signal” itself.
Focus of interest for the scientists from the research group directed by Prof. Michael Brand, was the signal protein FGF8. It holds a key function for the development of vertebrates as well the early formation of brains, hearts and limbs – without FGF8, deformations will occur. Aided by Fluorescence correlation spectroscopy, a highly sensitive quantitative measuring method, the scientists were able to show that the intake of substances into the cell (Endocytosis) is responsible for the correct encoding of FGF8 signals.
Therefore, the signal as well as the signal recording and the interpretation within the cell were measured within a living, still developing organism. “The quite surprising result was that the way cells handle incoming signals will also influence the following cells’ reaction to the signal. Whereas the signal remains the same outside the cell, the cells’ behaviour will change depending how the signal is being handled – as if a GPS-receiver, in this case the cell, is being reprogrammed”, says Dr. Matthias Nowak, one of Prof. Brand’s staff members.
Source: http://www.kompetenznetze.de/