In biology, scientists typically conduct experiments first, and then develop mathematical or computer models afterward to show how the collected data fit with theory. In his work, Rob Phillips flips that practice on its head. The Caltech biophysicist tackles questions in cellular biology as a physicist wouldby first formulating a model that can make predictions and then testing those predictions. Using this strategy, Phillips and his group have recently developed a mathematical model that accounts for the way genes compete with each other for the proteins that regulate their expression.
A paper describing the work appears in the current issue of the journal Cell. The lead authors on the paper are Robert Brewster and Franz Weinert, postdoctoral scholars in Phillips's lab.
"The thing that makes this study really interesting is that we did our calculations before we ever did any experiments," says Phillips, the Fred and Nancy Morris Professor of Biophysics and Biology at Caltech and principal investigator on the study. "Just as it is amazing that we have equations for the orbits of planets around stars, I think it's amazing that we are beginning to be able to write equations that predict the complex behaviors of a living cell."
A number of research teams are interested in modeling gene expressionaccurately describing all the processes involved in going from a gene to the protein or other product encoded by that DNA. For simplicity's sake, though, most such models do not take competition into consideration. Instead, they assume that each gene has plenty of whatever it needs in order to be expressedincluding the regulatory proteins called transcription factors. However, Phillips points out, there often is not enough transcription factor around to regulate all of the genes in a cell. For one thing, multiple copies of a gene can exist within the same cell. For example, in the case of genes expressed on circular pieces of DNA kn
|Contact: Deborah Williams-Hedges|
California Institute of Technology