DeNovo-HGT · The domestication, evolution, and adaptive role of horizontal gene transfer in eukaryotes.

The emergence and acquisition of new genes play a crucial role in the evolution of eukaryotes, providing new functions that contribute to adapting to changing environments and conquering unexplored niches through cellular innovations. Horizontal gene transfer (HGT), defined as the acquisition of genetic material from different species, has been shown to play a key role in eukaryotic genome evolution. HGT, particularly from bacteria and viruses, provides unprecedented adaptive potential by introducing novel functions into eukaryotic cells. However, new genes are often quickly lost because important constraints and evolutionary barriers need to be overcome for successful integration into the host genome. Despite the importance of HGT for eukaryotic biology, how this process works is still unclear and the mechanisms that contribute to the domestication of foreign genes, especially at the early stages, are unexplored. This project aims to develop a new experimental model for investigating HGT in eukaryotes using the green alga Chlamydomonas reinhardtii. For this, a bacterial antibiotic resistance gene (aphVIII) will be randomly integrated into the C. reinhardtii genome and its real-time functionalisation and evolutionary trajectories will be tracked. Using experimental evolution, I will identify genomic features that have a major impact on the control and stability of new genes. Additionally, I will analyze how HGT contributes to adaptation and impacts evolutionary flexibility in different scenarios. Finally, I will survey green algal diversity to understand how HGT contributed to the evolution of chlorophytes. Hence, this interdisciplinary project, combining molecular biology, experimental evolution, and computational methods, will offer unprecedented insights into the mechanisms of HGT in eukaryotes and answer fundamental questions in evolutionary biology, many of which have important implications for genome engineering and biotechnology.