The major interest of my studies is the aspect of phylogenetic interaction between symbiotically associated taxa. As a model system I work with a lichenized group of ascomycetes and their photobionts. These are the Physciaceae and Trebouxia. Initially, separate phylogenies are elaborated for both bionts and subsequently compared. The genetic marker primarily analysed in both bionts, is the nrITS region. In an early phase of my work I also sequenced the nrSSU of the Physciaceae and it turned out that these fungi are exceptionally rich in group I and splicosomal introns. To extend this aspect, I had the chance to work in Francois´ lab for three months.