Colloquium of the Faculty of Biology and Pharmacy

Genomic parasites of social amoebae - How to survive in a compact genome?"

Prof. Dr. Thomas Winckler

Institute of Pharmacy, FSU Jena

Transposable elements are found in virtually all organisms and play central roles in shaping their host's genomes. The amplification of these genomic parasites is a constant threat to host fitness due to the intrinsic process of integration into the genomic DNA that can cause mutagenesis of genes and force illegitimate recombinations between distant transposon copies. Haploid and gene-dense genomes like those of the Dictyostelid social amoebae are nice models to study the coevolution of host cells with their genomic parasites. Because transposons are confronted with a high risk of jeopardizing host genome stability and eliminating themselves along with their host, they are under selective pressure to invent strategies to avoid direct damage to the host by insertional mutagenesis. A process of convergent evolution is observed in the genome of the model species Dictyostelium discoideum that has repeatedly generated the selection of tRNA genes as probable "safe homes" for retrotransposons. In my talk I will summarize what we have learned so far about the molecular mechanims that Dictyostelium retrotransposons use to identify tRNA genes as integration sites. From the perspective of pharmaceutical drug development, studying molecular mechanisms of site-specific integration in non-human model organisms may promote human gene therapy through the design of specifically integrating gene transfer vectors with low intrinsic genotoxic potential.