Biophysical Society Thematic Meeting| Santa Cruz 2018

Genome Biophysics: Integrating Genomics and Biophysics to Understand Structural and Functional Aspects of Genomes

Thursday Speaker Abstracts

What Gene Expression Noise Tells About the Spatiotemporal Organization of Gene Regulatory Networks Alexander Wood 1 ; Ruud Stoof 1 ; Angel Goni-Moreno 1 ; 1 Newcastle University, School of Computing, Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom Gene expression noise is not only the consequence of mere random fluctuations, but also a signal that reflects physical dynamics of upstream regulatory machinery.Many bacteria exploit such noisy signals to deploy metabolic bet-hedging and/or division of biochemical labor, permitting clonal cells to exhibit different phenotypes and thus making populations more resistant to environmental shocks. This suggests that each gene and each protein of a given genetic network might need a specific location within the volume of a cell for optimal performance – an issue that has received relatively little attention. We studied promoter activity in regard to its distance to its regulating transcription factor source. Experiments with engineered bacteria in which that distance is minimized or enlarged highlighted the implication of spatial effects in gene expression patterns. In particular, it was found that gene expression noise was greater when the controlling transcription factor expression site was moved a greater distance from the promoter.Computational analysis suggested that the information about the geometrical architecture of genetic networks is finely encoded in gene expression signals. This approach allowed deconvolution of experimental data into spatial mechanistic information of gene regulation and provided a basis for selecting programmable noise levels in synthetic regulatory circuits.

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