Cis-Regulatory Logic Produces Gene-Expression Noise Describing Phenotypic Heterogeneity in Bacteria

Abstract

Gene transcriptional process is random. It occurs in bursts and follows single-molecular kinetics. Intermittent bursts are measured based on their frequency and size. They influence temporal fluctuations in the abundance of total mRNA and proteins by generating distinct transcriptional variations referred to as “noise”. Noisy expression induces uncertainty because the association between transcriptional variation and the extent of gene expression fluctuation is ambiguous. The promoter architecture and remote interference of different cis-regulatory elements are the crucial determinants of noise, which is reflected in phenotypic heterogeneity. An alternative perspective considers that cellular parameters dictating genome-wide transcriptional kinetics follow a universal pattern. Research on noise and systematic perturbations of promoter sequences reinforces that both gene-specific and genome-wide regulation occur across species ranging from bacteria and yeast to animal cells. Thus, deciphering gene-expression noise is essential across different genomics applications. Amidst the mounting conflict, it is imperative to reconsider the scope, progression, and rational construction of diversified viewpoints underlying the origin of the noise. Here, we have established an indication connecting noise, gene expression variations, and bacterial phenotypic variability. This review will enhance the understanding of gene-expression noise in various scientific contexts and applications.

Evaluation of Azithromycin and Fenugreek Oil as Anti-virulence Agents against Stenotrophomonas maltophilia MultiDrug Resistant Clinical Isolates

“…In contrast, protease gene expression upregulation in the presence of AZM or FO provides a discrepancy with the absence of phenotypic protease activity in the absence of either agent. Upregulated gene expression that corresponds to absent phenotypic characteristics may be explained through phenotypic heterogeneity phenomenon; due to different genetic or epigenetic factors (Darja, 2007;Magdanova & Golyasnaya, 2013;Chowdhury et al, 2021). Another probable explanation for this discrepancy is the presence of macromolecular crowding and aggregation of mRNAs and proteins forming complexes that are immobile or slowly mobile, contributing to slow diffusion and localization of mRNAs and hence greatly affecting translation (Zhdanov, 2014).…”