FACS-seq profiling of endogenous promoters of E.coli and a combination of 300 promoters and 13 RBSs

Research into phenotypic heterogeneity - the phenotypic differences found among a population of cells with the same genetic background and extracellular environmental conditions - has been greatly restricted by current low-throughput characterization approaches. To overcome this, we here propose a data processing pipeline for fluorescence-activated cell sorting and high-throughput DNA sequencing (FACS-seq) that profiles the gene expression distribution of thousands of variants simultaneously. As a proof of concept, we demonstrated the algorithm's ability to precisely characterize the expression properties of independent datasets. To analyze noise production, we used our method to investigate the expression characteristics of (1) 3,804 Escherichia coli MG1655 endogenous promoters and (2) a combination of 300 promoters and 13 ribosome binding sites (RBSs) in E. coli.