Resurrecting LUCA - Engineering of RNA-encoded Cellular Life Using Dual Evolution and Intergenomic Transplantation

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Modern cellular life strictly depends on DNA as genetic material. However, a large body of evidence infers the existence of a previous, more primitive biology in which RNA also stored information in cellular entities. Recreating a living cellular fossil representing this transition from an ancient RNA world to modern DNA-based life would fundamentally advance our understanding of our biology’s history, and enable us to explore its biological properties experimentally. However, the reengineering of existing molecular systems into a viable doppelganger of the Last Universal Common Ancestor (LUCA) or one of its precursors is extremely challenging. I propose to use a novel, combined top-down and bottom-up approach to create a modern-day doppelganger of LUCA by engineering bacterial hybrids with core cellular functions encoded on RNA. Using Darwinian Evolution as driver, my team and I will prototype and refine synthetic RNA-replicons through alternating replication in both cell-free and intracellular environments. This “dual evolution” approach will shape increasingly complex RNA networks capable of encoding complex genetic information. Following this, we will use these networks to create information-rich RNA chromosomes, enabling the transfer of essential genomic information from DNA to RNA. Finally, we will address this intergenomic transplantation by combining a novel RNA-delivery strategy with iterative rounds of genome deletion and complementation using state-of-the art CRISPR-Cas9 assisted genome editing. The proposed research will fundamentally advance synthetic biology, and could positively answer the transformative questions: Can we create, program and evolve life-like systems that can survive in both cell-free and intracellular environments? Can we use these entities to construct an alternative biology in which central cellular activities are encoded on genomes not made of DNA?