The Long Road to a Synthetic Self-Replicating Central Dogma

Abstract

The construction of a biochemical system capable of self-replication is a key objective in bottom-up synthetic biology. Throughout the past two decades, a rapid progression in the design of in vitro cell-free systems has provided valuable insight into the requirements for the development of a minimal system capable of self-replication. The main limitations of current systems can be attributed to their macromolecular composition and how the individual macromolecules use the small molecules necessary to drive RNA and protein synthesis. In this Perspective, we discuss the recent steps that have been taken to generate a minimal cell-free system capable of regenerating its own macromolecular components and maintaining the homeostatic balance between macromolecular biogenesis and consumption of primary building blocks. By following the flow of biological information through the central dogma, we compare the current versions of these systems to date and propose potential alterations aimed at designing a model system for self-replicative synthetic cells.

Leveraging Active Learning to Establish Efficient In Vitro Transcription and Translation from Bacterial Chromosomal DNA

“…Our results prove that high gene expression can be achieved at lower concentrations of template DNA and cell lysate. This narrows the gap between the amount of proteins required to carry out gene expression and the amount that is synthesized de novo , an aspect that will be crucial for building a sustainable replicating system in vitro . However, it is evident that there is much room for improvement of the protein synthesis efficiency in cell-free systems.…”

“…This narrows the gap between the amount of proteins required to carry out gene expression and the amount that is synthesized de novo , an aspect that will be crucial for building a sustainable replicating system in vitro. 44 However, it is evident that there is much room for improvement of the protein synthesis efficiency in cell-free systems. An intuitive way to achieve this would be to avoid synthesizing excess mRNA, but our experiments show that transcription is already limiting in our system, and hence, this cannot be the solution.…”

Emergent Information Processing: Observations, Experiments, and Future Directions

“…John von Neumann's self-replicator (the seminal work) [16] and Langton's minimal self-replicator [17] are the prominent examples. Self-replication in biology and chemistry [69][70][71][72].…”