Synthetic Biology: From Molecules to Artificial Evolving Chemical Systems

Steven Benner

Many languages have words, called contranyms, that have two opposite meanings. For example, a "citation" from Harvard University is good, but a "citation" from the Harvard University police is bad. If you run "fast", you are moving at great speed; if you hold "fast", you are not moving at all.

"Synthetic biology" is a contranym. In a version popular today among engineers, "synthetic biology" seeks to use natural parts of biological systems (like DNA fragments or protein "biobricks") to create assemblies that do things that are not done by natural biology (such as digital computation or specialty chemical manufacture). Among chemists, "synthetic biology" means the opposite. Chemist's "synthetic biology" seeks to use unnatural molecular parts to do things that are done by natural biology. Chemists believe that if they can reproduce biological behavior without making an exact molecular replica of a natural living system, then they have demonstrated an understanding of the intimate connection between molecular structure and biological behavior, under the dictum of Richard Feynman, in the phrase: "What I cannot create, I do not understand".

This talk will address one of the "grand challenges" in synthetic biology, an attempt to create an artificial assembly of organic molecules that reproduces Darwinian evolution, the archetypal feature of living systems. We will focus on synthetic genetic systems that resemble natural DNA in many ways, but have 12 independently replicating nucleotide "letters" in their genetic "alphabet". We will show the fundamentals of the chemistry behind genetic systems, how they can be manipulated, and how unnatural systems can mimic biological behaviors. We will then discuss how synthetic genetics can be applied, in diagnostics and research, to personalize patient care, to explore human genetic diversity, and to construct unusual nanostructures.