title: The nature of systems biology.
abstract: The advent of functional genomics has enabled the molecular biosciences to come a long way towards characterizing the molecular constituents of life. Yet, the challenge for biology overall is to understand how organisms function. By discovering how function arises in dynamic interactions, systems biology addresses the missing links between molecules and physiology. Top-down systems biology identifies molecular interaction networks on the basis of correlated molecular behavior observed in genome-wide "omics" studies. Bottom-up systems biology examines the mechanisms through which functional properties arise in the interactions of known components. Here, we outline the challenges faced by systems biology and discuss limitations of the top-down and bottom-up approaches, which, despite these limitations, have already led to the discovery of mechanisms and principles that underlie cell function.
authors.affiliation: Molecular Cell Physiology, Institute for Molecular Cell Biology, BioCentrum Amsterdam, Faculty for Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam, The Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Bruggeman
authors.forename: Hans V
authors.initials: HV
authors.lastname: Westerhoff
mesh_terms: D002468:Cell Physiological Phenomena; D023281:Genomics / Q000639:trends; D008967:Molecular Biology / Q000379:methods*; D049490:Systems Biology / Q000379:methods* / Q000639:trends*