PT  - JOURNAL ARTICLE
AU  - Elowitz, Michael B.
AU  - Levine, Arnold J.
AU  - Siggia, Eric D.
AU  - Swain, Peter S.
TI  - Stochastic Gene Expression in a Single Cell
AID  - 10.1126/science.1070919
DP  - 2002 Aug 16
TA  - Science
PG  - 1183--1186
VI  - 297
IP  - 5584
4099  - http://science.sciencemag.org/content/297/5584/1183.short
4100  - http://science.sciencemag.org/content/297/5584/1183.full
SO  - Science2002 Aug 16; 297
AB  - Clonal populations of cells exhibit substantial phenotypic variation. Such heterogeneity can be essential for many biological processes and is conjectured to arise from stochasticity, or noise, in gene expression. We constructed strains of Escherichia coli that enable detection of noise and discrimination between the two mechanisms by which it is generated. Both stochasticity inherent in the biochemical process of gene expression (intrinsic noise) and fluctuations in other cellular components (extrinsic noise) contribute substantially to overall variation. Transcription rate, regulatory dynamics, and genetic factors control the amplitude of noise. These results establish a quantitative foundation for modeling noise in genetic networks and reveal how low intracellular copy numbers of molecules can fundamentally limit the precision of gene regulation.