Gene network robustness as a multivariate character

TL;DR

This study investigates how different aspects of gene network robustness to genetic and environmental disturbances can evolve independently, revealing correlations and variability in robustness components through theoretical modeling and simulations.

Contribution

The paper introduces a theoretical framework and simulations to analyze the independent evolution of multiple robustness measurements in gene regulatory networks.

Findings

Robustness measurements are substantially correlated.

Robustness components can evolve differently under selection.

Robustness to mutations and environment can have distinct evolutionary paths.

Abstract

Robustness to genetic or environmental disturbances is often considered as a key property of living systems. Yet, in spite of being discussed since the 1950s, how robustness emerges from the complexity of genetic architectures and how it evolves still remains unclear. In particular, whether or not robustness is independent to various sources of perturbations conditions the range of adaptive scenarios that can be considered. For instance, selection for robustness to heritable mutations is likely to be modest and indirect, and its evolution might result from indirect selection on a pleiotropically-related character (e.g., homeostasis). Here, I propose to treat various robustness measurements as quantitative characters, and study theoretically, by individual-based simulations, their propensity to evolve independently. Based on a simple evolutionary model of a gene regulatory network, I showed that five measurements of the robustness of gene expression to genetic or non-genetic disturbances were substantially correlated. Yet, robustness was mutationally variable in several dimensions, and robustness components could evolve differentially under direct selection pressure. Therefore, the fact that the sensitivity of gene expression to mutations and environmental factors rely on the same gene networks does not preclude distinct evolutionary histories of robustness components. This article has been peer-reviewed and recommended by Peer Community In Evolutionary Biology Posted: 30th March 2022 (https://doi.org/10.24072/pci.evolbiol.100138)