Director of studies: Dr. Remo Sanges
Department of Biology and Evolution of Marine Organisms
There is a battle going on in our genomes. This battle is present in an overwhelming portion of the tree of life. A transposable element (TE) is a genomic sequence that can duplicate itself in a different position within the genome. During a wave of transposition insertions, a specific TE invades a specific genome having a limited range of time to amplify itself until the assaulted genome evolve the epigenetic competence to silence it. This control is not always complete, some TE copies might retain limited activity to perpetuate their amplification. In this way they bypass their extinction as a consequence of the accumulation of mutations, but do not retain the potential to completely destroy the invaded genome. At this stage, TEs are defined "domesticated" and they should not be considered anymore mere barbarian parasites. A growing body of evidences suggests they should be better regarded as "symbionts". Indeed, although mutagenic, they provide fresh genomic matter that can be shaped by the host genome to evolve genetic novelties. The genomes of living organisms contain a high percentage of TEs. This can vary substantially among different species, but researchers are beginning to demonstrate that the more an organism is complex (it presents many different kind of cells), the higher is the percentage of such elements into the genome. Therefore, understanding the evolution of these elements would allow us to better understand how complexity evolved. We propose to develop specific bioinformatics pipelines to evaluate how these features of the genome are evolutionary related and how they shaped the eukaryotic genomes and complexity. This project departs from interesting outcomes recently gained in our research projects focusing around the sequencing of transcriptomes from diverse marine organisms and the development of related bioinformatics pipelines. Analyzing the genome and the transcriptome from many sequenced species, at different level of complexity, we aim at understand whether the expansion of TEs, in relation to the evolution of complexity, is a basic principle of biology. Finally, the better understanding of the evolution and the functional impact of these element is also important from a biotechnological perspective, indeed the unique characteristic of these elements, to specifically bind, edit and modify any genome, make them an attractive system for a vast repertoire of molecular applications.
