Solving Puzzles With Missing Pieces: The Power of Systems Biology

Life is a program written in DNA. Starting in 1995, genome sequences detailing this program have ushered in a new point of view in biology: a true systems-level, or genome-scale, perspective. The genome sequence for an organism is analogous to having a component list for a circuit, except that many connections between components, and even some of the component functions themselves, are unknown. So how do we solve a puzzle when there are pieces missing? Enter systems biology. The combination of full genome sequences with over half a century of research in genetics, molecular biology, and biochemistry has enabled the genome-scale reconstruction of networks underlying well-studied cellular functions, such as metabolism. A quality-controlled reconstruction process effectively produces a circuit diagram of the metabolic network encoded in an organism's genome that can be modeled mathematically. Thus, a first principles ``bottom-up'' approach to systems biology rooted in fundamental mechanisms has arisen, and the quest to reveal the program that DNA encodes is underway. This article will familiarize you with some of the engineering concepts, methods, and applications in systems biology.