Single-Cell Biophysics: Measurement, Modulation, and Modeling

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Single-Cell Biophysics: Measurement, Modulation, and Modeling Poster Abstracts
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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. Smith1,3, Patrick S. Stumpf1,3, Sonya J. Ridden2, Aaron Sim4, Sarah Filippi5 ,
Heather A. Harrington6, Ben D. MacArthur1,2,3.
1University of Southampton, Southampton, United Kingdom, 2University of Southampton,
Southampton, United Kingdom, 3University of Southampton, Southampton, United
Kingdom, 4Imperial College, London, United Kingdom, 5University of Oxford, Oxford, United
Kingdom, 6University 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.