Single-Cell Biophysics: Measurement, Modulation, and Modeling

Single-Cell Biophysics: Measurement, Modulation, and Modeling

Poster Abstracts

84-POS Board 42 The Observer Effect in Cell Biology: Gene Expression Noise, Genetic Reporters and the Problem of Measurement in Live Cells Rosanna C. Smith 1,3 , Patrick S. Stumpf 1,3 , Sonya J. Ridden 2 , Aaron Sim 4 , Sarah Filippi 5 , Heather A. Harrington 6 , Ben D. MacArthur 1,2,3 . 1 University of Southampton, Southampton, United Kingdom, 2 University of Southampton, Southampton, United Kingdom, 3 University of Southampton, Southampton, United Kingdom, 4 Imperial College, London, United Kingdom, 5 University of Oxford, Oxford, United Kingdom, 6 University of Oxford, Oxford, United Kingdom. Fluoresence reporters allow investigation of temporal changes in protein expression in live cells and are consequently an essential measurement tool in modern molecular biology. However, their utility is dependent on their accuracy, and the effects of reporter constructs on endogenous gene expression kinetics are not well understood. Here, using a combination of mathematical modelling and experiment, we show that widely used reporter strategies can systematically disturb the dynamics they are designed to monitor, sometimes giving profoundly misleading results. We illustrate these results by considering the dynamics of the pluripotency regulator Nanog in embryonic stem cells, and show how reporters can induce heterogeneous Nanog expression patterns in reporter cell lines that are not representative of the wild-type. These findings help explain the range of published observations of Nanog variability and highlight the problem of measurement in cell biology in relation to genetic reporters.

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