Coherent regulation in yeast cell cycle network

TL;DR

This paper introduces a measure of coherence in gene regulatory networks, demonstrating that yeast cell-cycle regulation exhibits exceptionally high coherence likely due to evolutionary optimization for energy efficiency.

Contribution

It proposes a new measure of regulatory coherence and applies it to yeast cell-cycle networks, revealing their high level of coordinated activity compared to random networks.

Findings

Yeast cell-cycle network shows higher coherence than random networks.

Coherence correlates with network size, connectivity, and interaction types.

High coherence suggests evolutionary selection for efficient regulation.

Abstract

We define a measure of coherent activity for gene regulatory networks, a property that reflects the unity of purpose between the regulatory agents with a common target. We propose that such harmonious regulatory action is desirable under a demand for energy efficiency and may be selected for under evolutionary pressures. We consider two recent models of the cell-cycle regulatory network of the budding yeast, Saccharomyces cerevisiae, as a case study and calculate their degree of coherence. A comparison with random networks of similar size and composition reveals that the yeast's cell-cycle regulation is wired to yield and exceptionally high level of coherent regulatory activity. We also investigate the mean degree of coherence as a function of the network size, connectivity and the fraction of repressory/activatory interactions.