Genetic properties underlying transcriptional variability in Escherichia coli

The rate and direction of phenotypic evolution depend on the availability of phenotypic variants induced genetically or environmentally for selection. It is widely accepted that organisms do not display uniform phenotypic variation, where certain variants arise more frequently than others in response to genetic or environmental perturbations. Previous studies have suggested that gene regulatory networks governing phenotypes may channel both environmental and genetic influences. However, the properties of gene regulation that determine the rate and direction of phenotypic variation remain unknown. To address this issue, we characterized transcriptional variations in Escherichia coli in response to environmental and genetic perturbations. Based on the current understanding of transcriptional regulatory networks, we identified common genetic properties that account for gene-to-gene differences in the magnitude and directionality of transcriptional variation in both environmental and genetic causes. Our findings support the relevance of gene regulatory networks in shaping the phenotypic variability shared by different perturbations. This study provides insights into ability of gene regulatory network to learn about past environments in order to generalize to new environments.