Computational modeling of differences in the quorum sensing induced luminescence phenotypes of \textit{Vibrio harveyi} and \textit{Vibrio cholerae}

TL;DR

This study develops a computational model to explain the contrasting luminescence phenotypes of Vibrio harveyi and Vibrio cholerae, revealing how a key parameter influences sRNA interactions and phenotypic outcomes.

Contribution

The paper introduces a unified model that explains differences in quorum sensing-induced luminescence phenotypes between V. harveyi and V. cholerae based on sRNA interactions and a critical protein concentration parameter.

Findings

The model identifies a key parameter controlling additive or redundant sRNA effects.

Differences in this parameter can explain mutant phenotype variations.

The model predicts testable outcomes for future experiments.

Abstract

\textit{Vibrio harveyi} and \textit{Vibrio cholerae} have quorum sensing pathways with similar design and highly homologous components including multiple small RNAs (sRNAs). However, the associated luminescence phenotypes of strains with sRNA deletions differ dramatically: in \textit{V. harveyi}, the sRNAs act additively; however, in \textit{V. cholerae}, the sRNAs act redundantly. Furthermore, there are striking differences in the luminescence phenotypes for different pathway mutants in \textit{V. harveyi} and \textit{V. cholerae}. However these differences have not been connected with the observed differences for the sRNA deletion strains in these bacteria. In this work, we present a model for quorum sensing induced luminescence phenotypes focusing on the interactions of multiple sRNAs with target mRNA. Within our model, we find that one key parameter -- the fold-change in protein concentration necessary for luminescence activation -- can control whether the sRNAs appear to act additively or redundantly. For specific parameter choices, we find that differences in this key parameter can also explain hitherto unconnected luminescence phenotypes differences for various pathway mutants in \textit{V. harveyi} and \textit{V. cholerae}. The model can thus provide a unifying explanation for observed differences in luminescence phenotypes and can also be used to make testable predictions for future experiments.