AG Molecular Ecology (Kristina Sefc)

Our research focusses on the diversity of animal organisms at different levels, from individual plasticity to macroevolutionary processes.
Kristina Sefc's taxonomic focus is on cichlid species of the East African Lake Tanganyika, which are characterised by extraordinary diversity in behaviour, appearance and ecological intermixing. This enables comparative studies of mating systems, brood care behaviour and population structure, taking into account biotic and abiotic environmental conditions and environmental changes. Projects on mating and social systems utilise data collection under natural conditions as well as field and laboratory experiments, often combined with genetic relationship analyses. Another focus is on the evolution of one of the most important means of communication in cichlids, namely their body colouration. Experiments on their function are combined with analyses of the molecular basis of body colouration in order to get to the bottom of the remarkable evolvability of the colour patterns of cichlids.

Christoph Hahn investigates the fundamentals and consequences of evolutionary processes, such as adaptation, diversification and speciation, in the genome. He mostly, but not exclusively, uses aquatic organisms such as parasitic flatworms, rotifers, East African cichlids and other fish as models. In his work, Christoph mainly relies on bioinformatic analyses of "large" genomic and transcriptomic data sets.
A current research focus is the evolution of parasitism. Parasitic flatworms, and in particular hookworms (Monogenea), a relatively unknown but very species-rich (~100,000) and globally distributed group of vertebrate parasites, serve as a model here. Our research focusses on the reconstruction of the early evolutionary history of parasitism within flatworms, which probably goes back to the origin of vertebrates, as well as our understanding of the molecular genetic basis of the interaction between parasite and host and the expression of different forms of parasitism, e.g. ecto- vs. endoparasites or simple vs. complex life cycles. We generate and interpret genomic and transcriptomic data together with a large number of international co-operation partners.
As part of the ABOL (Austrian Barcode of Life) initiative, Christoph Hahn is also researching hook-sucking worms of the genus Gyrodactylus in Austria. From 2017 to 2019, the research led to the first records of around 20 species, some of which are potentially new to science. For the research and monitoring of aquatic biodiversity, especially of fish, we are increasingly using data generated from so-called environmental DNA (eDNA), in particular from water samples that contain the smallest amounts of organismic DNA, either free-floating or still bound in cells. A particular focus here is the development of robust and reproducible methods for the bioinformatic analysis of these data.