Work

Orsay virus infection is associated with reduced locomotion and alters cue-dependent food choice in Caenorhabditis elegans

Year: 2026

Type: preprint

Abstract: Behavioral responses are an important component of host defense; however, most evidence in Caenorhabditis elegans comes from bacterial pathogens. Here, we tested whether infection with Orsay virus (OrV) alters host dispersal and food choice and whether these responses involve the RNA-processing factor EOL-1. When measuring distance travelled over a certain period of time in control and infected wild-type animals, we observed that OrV infection was associated with lower locomotion. Moreover, when presenting infected and control animals with food choices, we observed that infected animals preferred OrV infected food sources only when the alternative was a pure food source, preferring a non-inoculated food source when both control and viral food sources contained a C. elegans filtrate. Moreover, loss of EOL-1 altered baseline locomotion and attenuated the infection-associated reduction detected in the earlier motility assay, while also modifying the food choice response, suggesting that eol-1 contributes to the motility and behavioral changes induced by OrV infection. Collectively, these results support an overall association between OrV infection and reduced host dispersal, whereas its effect on food choice depends on the sensory context. These findings extend infection-associated behavioral responses to a natural viral pathogen and identify eol-1 as a modulator of their expression. IMPORTANCE This study advances our understanding of the interplay between viruses and host behavior by demonstrating that natural infection with OrV is associated with reduced motility and alters food choice in C. elegans in a cue context-dependent manner. In addition, it identifies eol-1 as a genetic modulator of these responses, linking infection status to sensory processing and behavior. Taken together, these findings extend the concept of behavioral immunity beyond bacterial pathogens and establish the C. elegans -OrV system as a valuable model for investigating the neurogenetic basis of behavioral changes induced by viral infections.

Source: bioRxiv (Cold Spring Harbor Laboratory)

DOI: 10.64898/2026.11.04.764174