Role of signal degradation in directional chemosensing

TL;DR

This paper investigates how signal degradation, coupled with diffusion, can paradoxically enhance directional chemosensing, challenging traditional views and showing that degradation can sometimes improve sensory information in biological systems.

Contribution

The study introduces a reaction-diffusion model revealing that signal degradation can increase information, identifying a non-Markovian mechanism that evades the data processing inequality.

Findings

Degradation can improve sensory information in diffusion-based systems.

Mating yeast operate in a regime where degradation benefits sensing.

A reaction-diffusion model demonstrates nonlocal effects in chemosensing.

Abstract

Directional chemosensing is ubiquitous in cell biology, but some cells such as mating yeast paradoxically degrade the signal they aim to detect. While the data processing inequality suggests that such signal modification cannot increase the sensory information, we show using a reaction-diffusion model and an exactly solvable discrete-state reduction that it can. We identify a non-Markovian step in the information chain allowing the system to evade the data processing inequality, reflecting the nonlocal nature of diffusion. Our results apply to any sensory system in which degradation couples to diffusion. Experimental data suggest that mating yeast operate in the beneficial regime where degradation improves sensing.