Efficient pheromone navigation via antagonistic detectors in Caenorhabditis elegans male

TL;DR

C. elegans males use opposing signals from head and tail sensors to navigate toward mates by interpreting pheromone gradients.

Contribution

The study reveals a novel antagonistic sensory strategy in C. elegans males for pheromone-based navigation.

Findings

AWA neurons promote forward movement while PHD neurons induce reversals in response to pheromone gradients.

An antagonistic integration of head and tail sensory inputs enables reliable mate tracking in dynamic environments.

Abstract

Chemotaxis to a moving potential mate that emits a volatile sex pheromone poses a navigation challenge requiring rapid, precise responses to maximize reproductive success. Volatile chemicals form gradients that differ from soluble compounds, potentially making navigation based on comparisons between spatially separated sensors unreliable for small-bodied animals. Here we show that, rather than a simple spatial comparison, Caenorhabditis elegans males employ an antagonistic strategy, comparing inputs from sex-shared head (AWA) and male-specific tail (PHD) sensory neurons with distinct response properties. Despite sharing a receptor, SRD-1, these detectors play different roles: AWAs promote forward movement and acceleration, while PHDs induce reversals and deceleration. In rising pheromone gradients, AWA activity dominates; in falling gradients, AWA inactivates, allowing PHD to correct trajectories. AWAs are essential for mate-searching, while PHDs are crucial for complex tasks. A minimal computational model reproduces these behaviors and infers how head–tail signals are combined. Thus, a sexually dimorphic, antagonistic sensory system enables adaptive navigation in dynamic environments

In this study, the authors show C. elegans males locate moving mates by weighing pheromone cues sensed in the head and tail that trigger opposite movements, enabling an antagonistic integration for reliable tracking in dynamic environments.

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