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

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.