center for systems

& synthetic biology

an NIGMS national systems biology center


Not all noise is created equal

September 28, 2012

Intrinsic noise in gene expression can come from two main sources: promoter fluctuations and mRNA birth/death fluctuations. Now Center investigator Leor Weinberger and colleagues present a perturbation method in Molecular Systems Biology that can distinguish between these sources of noise by measuring transient changes in protein variance. The authors apply their method to HIV-1 gene expression, and demonstrate that promoter fluctuations are the primary source of noise in that system.