Research interest
        I am fascinated by the tremendous biological diversity in nature and especially interested in the never ending dynamics of host-parasite co-evolution and the molecular mechanisms that have evolved in vertebrate hosts to resist their pathogens. I am intrigued by the fact that hosts can cope with the vast spectrum of pathogens that they face in their natural environment, all of which are constantly evolving new tricks and tweats to best expoit their host's resources. Even intruders that they have never encountered before are recognized as foreign and fought against.

 Never-ending coevolution
MHC molecule
        In vertebrates - apart from the first defence line of the innate immune system - the backbone of the ability to recognize foreign, or better, non-self antigens of invading pathogens is the Major Histocompatibility Complex (MHC). MHC molecules present these antigens at the cell-surface and thus play a critical part in the initation of the adaptive immune response. However, every individual can only carry a restricted number of different MHC alleles and is therefore vitaly dependent on having the most successful genotype, i.e. the allele combination that guarantees the broadest antigen presentation of the predominating pathogens. The MHC region, in fact, exhibits some of the highest polymorphism in the vertebrate genome, comprising a large number of alleles and high allele divergence at the population level as well as high heterozygosity and a variable number of loci at the individual level. This polymorphism evolved and has been maintained by balancing selection, presumably driven by the never-ending selection of coevolving pathogens.

        Over the years, I have studied several model and non-model organisms to unravel the molecular depths of this astounding gene complex and the evolutionary forces maintaining its polymorphism. Associations of MHC diversity and fitness parameters observed in natural populations were complemented by experimental approaches in the lab. This work has contributed to our general understanding of the evolution of MHC genes, but also opened up new avenues of research and is still ongoing. In addition, I have recently started to apply some of the new insighty obtained from work with natural populations and non-model organisms to human populations. Here I am using computational tools to investigate the evolutionary significance of HLA (the human MHC) diversity at the population level and at the individual level. This work is greatly facilitated by the advent of next generation sequencing data and partly inspired by the growing interest in evolutionary medicine.