Lay summary

Genomes evolve through mutations, deletions and duplications of sequences. Several molecular mechanisms that drive these re-arrangements have been unraveled in recent years, but many questions are still not answered. Transposable elements (TEs) are mobile genetic units which can move around in the genome and/or make copies of themselves. Some TE are extremely successful colonisers which can reach thousands of copies in a genome. When the excise from or insert into the genome they can create double-strand breaks in the DNA that have to be repaired by the cell. This repair process is often not perfect and can lead to the loss or the duplication of DNA fragments. Recent results indicate that TEs are a major source of genetic variability and therefore probably one of the main driving force of genome evolution.

By comparing the complete genome sequences of three rice genomes we will study how often these TEs move and replicate in the genome. This will allows us to trace how much of their activity leads to DNA damage and what kind of rearrangements follow during the DNA repair process. Especially, we will investigate the frequency with which gene sequences are duplicated and moved across the genome in this process. Performing the same type of analysis also in animal (e.g. Drosophila) and fungal (e.g. yeast) genomes will reveal if the same mechanisms are at work in all eukaryotic genomes.