Roadmap to Building a Cell: An Evolutionary Approach

Abstract

Laboratory synthesis of an elementary biological cell from isolated components may aid in understanding of the fundamental principles of life and will provide a platform for a range of bioengineering and medical applications. In essence, building a cell consists in the integration of cellular modules into system's level functionalities satisfying a definition of life. To achieve this goal, we propose in this perspective to undertake a semirational, system's level evolutionary approach. The strategy would require iterative cycles of genetic integration of functional modules, diversification of hereditary information, compartmentalized gene expression, selection/screening, and possibly, assistance from open-ended evolution. We explore the underlying challenges to each of these steps and discuss possible solutions toward the bottom-up construction of an artificial living cell.

Towards a synthetic cell cycle

“…2a) 14 . Compartmentalised selfreplication is an essential step towards synthetic life, as well as a suitable approach for in vitro evolution of other modules 5 .…”

“…Even though ϕ29 DNA replication is currently the best developed system for eventually driving replication in a synthetic cell, there are relevant bottlenecks that need to be addressed. Firstly, the DNA amplification rates of the ϕ29 system in IVTT conditions should be optimised 17 , through adjusting the standard composition of IVTT reaction mixtures (PURE), and/or through laboratory evolution of the ϕ29 system itself 5,18 . Secondly, it is important to consider that the natural function of this phage system is to replicate a linear genome.…”

“…Another bottleneck of the ϕ29 system may be that the processivity of its DNAP (responsible for replicating its 20 kb genome) is not sufficient to enable replication of a single chromosome of the size needed for a synthetic cell 13,14 . As splitting the genome into multiple smaller chromosomes is not preferred (see below; DNA segregation), a potential solution could be to improve the processivity of ϕ29 DNAP by laboratory evolution 5 . As another route, replicase systems from known viruses with larger, circular dsDNA genomes (250-500 kb) might be suitable candidates for replicating the genome of a synthetic cell.…”

“…In this Perspective, we discuss major challenges and potential approaches to create a synthetic cell cycle. For comprehensive information about natural cell cycles, metabolic modules as well as general engineering and evolution strategies towards a synthetic cell, we refer to some excellent recent reviews [3][4][5] . Below, a comparison is made of promising modules for DNA replication, DNA segregation, and cell division.…”

Ciencia ficción de hoy, ciencia de mañana: construir una vida

“…Por lo tanto, se pueden utilizar diferentes modelos, pero el que más se parece a las células naturales es el liposoma, una vesícula acuosa encapsulada por una capa doble de fosfolípidos. Al ser biocompatible, se puede integrar más fácilmente con otros componentes, como proteínas de membrana y polisacáridos (Abil & Danelon, 2020).…”