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BP: Fachverband Biologische Physik
BP 19: Multi-cellular systems
BP 19.8: Vortrag
Dienstag, 17. März 2015, 11:45–12:00, H 1058
Dynamics and precision of mouse neural tube patterning — •Marcin Zagórski1, Anna Kicheva2, Gašper Tkačik1, James Briscoe2, and Tobias Bollenbach1 — 1Institute of Science and Technology (IST) Austria, Klosterneuburg — 2Medical Research Council (MRC), National Institute for Medical Research, London, UK
Early in vertebrate development, different neuronal subtypes are generated from neural progenitor cells arrayed along the dorsal-ventral axis of the neural tube. This pattern of neural progenitors is established by morphogens - signaling molecules secreted by cells in restricted source regions at the tissue boundaries. In the neural tube, the morphogens Shh and BMP form opposing concentration profiles which provide positional information to cells and induce the expression of target genes, such as Nkx6.1 and Pax3, at defined positions. It is not understood how the two morphogen signals and the regulatory interactions between target genes together determine the target gene pattern. To address this issue, we measured the two signaling gradients. We quantified the positional information available to the cells with both direct and Gaussian approximation techniques. Early in development, positional information is high, enabling patterning at a precision of three cell diameters; after 20h, however, precision declines significantly in the middle region. Still, after 30h, the expression boundary between Pax3 and Nkx6.1 is precisely specified in the middle. These results suggest that cells in the central neural tube integrate positional information from two opposing morphogen gradients early in development to achieve precise target gene boundary positions at later stages.