Using the sequencing information provided by other research groups, Andreas Hejnol and his team then examine, for instance, the genes involved in the formation of the nervous system of both the fly and the human – two very distantly related creatures. They then compare these observations with the function of these genes in more closely related animals – and also in animals that are even more distantly related. The scientists use these studies to understand the evolutionary role of molecules. In concrete terms, they are trying to find out how the function of molecules has changed within the course of evolution and the effects this has had on the structure of the nervous system. The nervous system is a good example of the development process of an organ system. In the course of evolution a neural network, which jellyfish, for example, still have today, has developed into a condensed bundle of nerve fibers in the form of the human spinal cord.
Microscopy plays a key role in the work of the “Comparative Developmental Biology” research group. First, Andreas Hejnol and his team use basic stereomicroscopes like the Leica M60 and M80 to identify the animal species. Under the Leica M165 with fluorescence filters, the scientists can establish transgenic lines, for example. “This process always takes a bit longer for animals taken from their natural habitat, explains Hejnol. “But with the Leica M165 we can also examine gene expression under the stereomicroscope – using markers like GFP.”