View Program - 2022 Population, Evolutionary, and Quantitative Genetics Conference

Gene expression noise refers to variation in gene expression among genetically identical cells. It can arise from diffusion, growth, or a particular combination of transcription factor, promoter, enhancer, or 3d position in the genome. Although originally thought to be detrimental, recent studies have highlighted that gene expression noise may confer a selective advantage in stressful or changing environments by producing heterogeneous phenotypes. Noise levels of genes should be determined by the structure of the gene regulatory network, and we expect promoters to play important roles in the propagation of expression noise of their target genes. However, only noise plasticity increases with the number of regulatory inputs of the promoter, without any change in mean expression. Here we study features of noisy genes within the E. coli regulatory network. We show that, whereas some noisy genes are generalists, most can be grouped into biological modules in a condition-specific manner. Finally, we compare the evolutionary and expression features of generalist and condition-specific noisy genes, providing insight into the forces driving gene expression noise in E. coli.

Gene expression noise in a pathway is condition-specific