Synthetic Biology: A New Frontier

Synthetic biology is a new field that combines engineering principles, mathematical modeling, and molecular biology techniques to design and construct novel biological parts, de- vices, and systems with applications in energy, medicine, environmental science, and technol- ogy. We discuss examples of mathematical models aiding in biological investigations, biology aiding in mathematical investigations, and the two fields working together in synthetic biology to attack some of the world's biggest problems. Opportunities abound for mathematicians to contribute to this budding field. 1. INTRODUCTION. In 1975, 140 scientists and ethicists convened a summit at Asilomar to discuss guidelines for research in the cutting-edge field of genetic engi- neering. Recombinant DNA technology had suddenly made it possible to fundamen- tally and permanently modify organisms by inserting functional elements from other organisms. Today, the methods of recombinant DNA technology are the foundation for another emerging field with the potential to revolutionize science on a similar scale. Synthetic biology is a diverse and rapidly growing field, only about a decade old, and all practitioners do not necessarily agree on a definition for the field. For our pur- poses, synthetic biology is the application of engineering principles and mathematical modeling to the design and construction of biological parts, devices, and systems with applications in medicine, environmental science, technology, and energy. Synthetic biology is distinguished from the related foundational field of genetics by its broad, systems-level approach, and from systems biology by its focus on building new systems rather than studying existing ones. Synthetic biologists often think like engineers, using the principles of abstraction and modularity to guide the design of new parts, devices, and systems. Modular designs are supported by standardization of assembly methods, so that DNA parts built according to the standards are inter- changeable. Descriptions of these parts are listed in an online catalog (16), and the parts themselves are freely available. Mathematical tools from a spectrum of subfields play an important part in synthetic biology research. As expected in mathematical biology, mathematical modeling and analysis can help scientists understand biological processes. Perhaps surprisingly, in synthetic biology, the converse is also true: Biological models and representations can help scientists solve mathematical problems. In this article we discuss some examples of each direction of this interaction between mathematics and biology. Finally, we highlight a number of recent synthetic biology projects in which many disciplines, including mathematics and computer science, have come together to attack some of the world's biggest problems. 2. MATHEMATICAL MODELING IN THE DESIGN OF SYNTHETIC BIOLOGICAL SYSTEMS. Our knowledge about biological systems has increased dramatically in the so-called genomic era, when it became possible to sequence entire organisms. But knowing the sequence of A's, C's, G's, and T's that make up a bac- terium, or a mouse, or a human, is just one step in understanding how genes function