|DAPT treated animal|
Hydra vulgaris is a member of the ancient phylum Cnidaria. We want to know how multicellular animals may have evolved from single celled protozoans and complex bilaterian animals from simply built non-bilaterians. Whole genome and EST sequencing of Hydra have shown that the major signalling pathways that are indispensable for development were already present in Cnidarians. The Notch signalling pathway is essential for cell specification and patterning in bilaterians. Similar processes are also influenced by Notch signalling in Hydra, e.g. stem cell differentiation and boundary formation. We have found interesting parallels in signalling events at the bud-parent boundary and boundaries that are formed during embryogenesis for organ formation in bilaterians. This might have implications for our understanding of the evolution of bilaterian body plans.
Multicellularity needs sophisticated mechanisms to maintain the equilibrium between different cell types within the organism. Apoptosis that is regulated by caspases and Bcl-2 family proteins is an important developmental mechanism to achieve such homeostasis in animals. We study the function of the surprisingly complex families of apoptotic proteins in Hydra in order to understand the evolutionary origins of apoptosis and how it is controlled by death and survival signals.