KENBIKYO Vol.50▶No.2 2015
■Feature Articles: ‌Novel Insights and Perspectives in Microbiology Obtained from Time-Lapse and Spatial Serial Observation of Single Bacterial and Yeast Cells

Visualization of Gene Expression Dynamics in Single Living Cells Using Single-Molecule Fluorescence Microscopy

Yuichi Taniguchi

Quantitative Biology Center, RIKEN

Abstract: Because of stochasticity in the gene expression process, protein and mRNA copy numbers in a single cell vary among a population of cells and fluctuate by time. However, quantification of heterogeneity and fluctuation of gene expression products, especially in low copy genes, was difficult because of lack of sensitivity. To approach this problem, we utilized single molecule fluorescence microscopy to quantify heterogeneity and dynamics of gene expressions in single cells with single molecule sensitivity. Measurements on 1,018 genes in model organism Escherichia coli show that distributions of protein copy numbers among a cell population are generally described with gamma distributions, whose parameters are controlled by transcription and translation rates. Furthermore, simultaneous measurements of protein and mRNA expression indicate that both copy numbers in a single cell are uncorrelated.

Key words: Single molecule fluorescence imaging, Gene expression noise, Genome-wide analysis, Large-scale data analysis, Microprocessing