Is stochastic gene expression linked to persistence in bacteria? A combined fluorescence and 'tip enhanced Raman scattering (TERS) study.

Recently it has become clear that non-genetically determined individual properties could be the result of small stochastic fluctuations in transcription and translation processes. Cellular biochemical processes in which a small number of (macro)molecules are involved, are intrinsically stochastic. This noise in gene expression can effect the coordination of the cell activity, but allows for a conscious indeterminism which can cause phenotypic heterogeneity. Persistence is the phenomena whereby a fraction of an isogenic bacterial population can withstand high doses of antibiotics. Recently, it was shown that the protein PerA is involved in the persistence of E. coli. An obvious hypothesis is that stochastic variation of the cellular PerA concentration gives rise to persistence in bacteria that have reached a PerA threshold value. In this research project we wish to investigate this hypothesis via a combined fluorescence and Raman analysis of gene expression on the single cell level. By linking stochastic gene expression to a phenotype and applying a combination of single molecule fluorescence microscopy, single cell Raman microscopy and tip enhanced Raman spectroscopy (TERS), this can lead to important new discoveries in this research area.

Keywords:Stochastic gene expression, Raman, TERS, Persistence

Disciplines:Biophysics, Physical chemistry, Sustainable chemistry