Morphogene substanzen ausHydra

We use hydra as a model system to understand how growth and differentiation and, as a consequence of this, pattern formation are controlled at the molecular level. We have found that four substances control head and foot formation in hydra: an activator and an inhibitor of head formation and an activator and an inhibitor of foot formation. The two activators are peptides with molecular weights around 1000 daltons, the inhibitors are smaller in molecular weight (<500), have an overall positive charge and do not contain peptide bonds. In normal animals all four substances are present and most likely produced by nerve cells. We hope to understand how these substances act and interact to create the spatial and temporal pattern of growth and differentiation typical for hydra.     

Reception of particle oscillation in a medium — an unorthodox sensory capacity

The oscillation of particles in a medium is the adequate stimulus for specialized receptors. Such receptors can be found in nearly all phyla in the animal kingdom. Specialized sensory hairs in arthropods are used here as an example to show conditions and limits of vibration reception in a medium. The use of this sensory capacity in biologically relevant situations is shown on some well-known examples.