In a paper published on 19 April 2022 in the renowned journal Nature Communications, the research group of Prof. Dr. Gerd Walz, Medical Director of the Department of Internal Medicine IV at the University Medical Centre Freiburg, was able to show that small labyrinth-like membrane protrusions on the cell surface are necessary to anchor motile cilia to the cell. The findings, which were made within the framework of the Cluster of Exellence CIBSS – Centre for Integrative Biological Signalling Studies at the University of Freiburg and the CRC NephGen, can help to better understand defects in cilia and the cause of associated diseases.

One focus of the research group led by CIBSS member Walz is to find out how so-called cilia are formed during development. This is the name given to hair-like structures on cells that are of central importance, for example, for transport of particles in the lungs, kidneys and brain. They are also important for the development of cells and tissues. Disorders of cilia function or structure lead to serious diseases, including polycystic kidneys, brain and heart malformations, obesity, blindness and liver fibrosis. The scientists in Walz's team are investigating this in clawed frogs, among others, and are using a state-of-the-art infrastructure at the University Medical Centre Freiburg for this purpose: the central unit of IMITATE for research into aquatic organisms called AquaCore. 

Learning about humans from African clawed frogs

Humans and African clawed frogs are both vertebrates and share about 21,000 of a total of 23,000 genes. This enables researchers to understand a lot about human development and diseases by studying this frog. Another advantage: "The animals lay a lot of transparent eggs whose development can be observed very easily in a Petri dish or with a light microscope. In addition, it is relatively easy to intervene in gene activity and function and thus understand the significance of individual genes," says Dr. Peter Walentek from the Cluster of Excellence CIBSS, that is part of Walze’s team. At the same time, the investigation of fish and frog eggs takes into account the 3-R principle, hence,. reducing the number of experimental animals, replacing them with other organisms or methods or refining the experiments. Thus, the study of the clawed frog can partially replace studies on mammals.

At the IMITATE Institute, the central unit AquaCore was opened, which enables complex studies of aquatic animal models.

State-of-the-art equipment, large capacities and collegial support in conducting experiments: This is what the newly established AquaCore unit at the Institute for Disease Modelling and Targeted Medicine (IMITATE) offers. In particular, the study of clawed frogs (Xenopus laevis, X. tropicalis) and zebrafish (Danio rerio) are the focus of research here. The AquaCore Facility team led by Walentek and PD Dr. Toma Yakulov from the Department of Internal Medicine IV at the University Hospital will support interested parties in planning and implementing their studies. In addition, researchers are also provided with the entire infrastructure of the unit, including places for microscopy, microinjection and cold preservation (cryopreservation). "The rooms and equipment at the AquaCore Facility are probably among the absolute best in the world," Walentek is pleased to say. The training and further education of researchers are also among the unit's central goals.

https://www.uniklinik-freiburg.de/aquacore.html

Original Publication:
Yasunaga, T., Wiegel, J., Bergen, M.D. et al. Microridge-like structures anchor motile cilia. Nat Commun13, 2056 (2022). doi.org/10.1038/s41467-022-29741-3