What Is Synthetic Biology?
While origin of life research generally pertains to figuring out the pathways of chemical systems that produced the earliest protocells (in a geochemically plausible scenario), there is a different yet overlapping field that is constantly approaching new frontiers - Synthetic Biology. Synthetic biology is directly concerned with building artificial life, whether it be in the form of protocells/cells, organisms with expanded or reduced genetic codes, synthetic DNA and genomes, hybrid biological systems, artificial organelles, and more.
Synthetic biology relies upon multiple scientific fields in order to expand its horizons, including but not limited to - bioengineering, biotechnology, molecular biology, genetics, nanotechnology, systems biology, chemical biology, and more. Although synthetic biology has seemingly limitless potential world-changing capabilities, from gaming to medicine, I am most interested in it's ability to build artificial protocells in order to further understand the origin of life. That is what this blog post will focus on.
Synthetic biologists can be categorized into two main groups. One group uses unnatural molecules to mimic emergent behaviors from natural biology, aiming to create artificial life. The other group seeks to use interchangeable parts from natural biology to construct systems that function in novel ways. In both approaches, pursuing synthetic goals compels scientists to explore uncharted territories, addressing problems that are not easily encountered through traditional analysis. This exploration leads to the development of new paradigms that analysis alone cannot readily achieve.
Building Artificial Life
In 2010, leading genomic scientist Craig Venter and his research team essentially constructed a synthetic copy of a bacterium's DNA that, once transplanted into an organism, took control of its functions. Obviously, this is different than creating a complete living synthetic organism, but nevertheless, it was a massive leap for the field of synthetic biology.
Cells are not only the building blocks of biological complexity; they are complex systems maintained by the coordinated interaction of multiple biochemical networks. Their replication, adaptation, and computational abilities arise from appropriate molecular feedback mechanisms. As recent decades have showcased the transition from the description-driven biology to the synthesis-driven biology, it has presented a common challenge to the fields of bioengineering and the origin of life - what are the proper conditions that lead to the emergence and persistence of living cellular structures?
Although self-replication and evolution are important abilities of cells, they do not necessarily need to be end goals of protocells constructed via synthetic biology. The artificial cell (Acell) could replicate but not evolve, or even be completely unable to self-replicate. Either way, a simple self-sustaining Acell could persist under specific conditions, exchanging energy and matter with its surroundings without growing. Although this might seem like a limited scenario, it is quite intriguing: one could design or guide the self-assembly of a protocell capable of performing certain functions or computations in predefined ways.
This article is meant as a general overview of synthetic biology. I will delve deeper into the actual methods that scientists employ in protocell construction in future blog posts.
References:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9788358/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2442389/
https://ntrs.nasa.gov/api/citations/20020043286/downloads/20020043286.pdf
