Dr. Arndt Siekmann


Dr. Arndt Siekmann
Dr. Arndt Siekmann
CiM-Logo-standard-RGB-60 Our lab is part of the Cluster of Excellence "Cells in Motion" (CiM).


Funded by the European Research Council (ERC), Deutsche Forschungsgemeinschaft (DFG).
Member of the 'Cells in Motion' Cluster of Excellence.
Member of the SFB629.

Laboratory for Cardiovascular Patterning


The goal of our lab is to understand the processes that are important for the proper formation of the cardiovascular system, which is the first organ system to form during development. It consists of an elaborately branched blood vessel tree, providing nutrients and oxygen to all parts of the body. Until 10 years ago, it was thought that the two main blood vessel types, arteries and veins differ solely in terms of their physiological properties: arteries carry oxygenated blood away from the heart and experience higher blood pressure, while veins have lower blood pressure and transport blood back to the heart. Since then it has become clear that arteries and veins are molecularly distinct even before the onset of blood flow and many arterial and venous specific marker genes have been identified. In addition, we begin to understand which signalling pathways help to pattern the cardiovascular system. Among these, the Notch and VEGF (Vascular Endothelial Growth Factor) signalling pathways have been shown to function in arterial differentiation and during the sprouting of new blood vessels from pre-existing ones, a process called angiogenesis.

Despite these recent advances, many open questions remain as of how endothelial cells coordinate their behaviours during the formation of the cardiovascular system. In order to better understand these processes, we utilize zebrafish as a model organism. The embryos of these fish offer unique advantages for the study of forming blood vessels. Available transgenic lines, marking endothelial cells with fluorescent proteins allow the in vivoobservation of the developing vascular system. In addition, forward and reverse genetic tools permit a detailed analysis of the genes important for endothelial development. Moving forward, an increased understanding of the mechanisms that pattern the cardiovascular system will help us in developing strategies for curing diseases with a vascular component, such as diabetes, stroke and cancer.

loading content