Charissa de Bekker, Utrecht University

Behavioural manipulators: unravelling the molecular mysteries of real-life zombie-making fungi

The evolutionary arms race between parasites and hosts can culminate into complex extended phenotypes that benefit disease progression and transmission. The fungus-adaptive changes in behaviour as seen in Ophiocordyceps-infected carpenter ants are a prime example. These “zombie ants” demonstrate behaviours that are thought to circumvent the social immune responses of the colony. Subsequently, the hijacked ant attaches itself at an elevated position that benefits fungal spore development and dispersal. The precise mechanisms involved are unknown. To unravel them, we have developed “zombie ants” into an integrative model system. By combining fungal culturing and lab infections with behavioural assays and multi-omics, we propose several hypotheses about the fungal proteins and ant receptors involved. To determine the function of presumed fungal “manipulation” effectors, the host behaviours they elicit, and the host pathways that underly those phenotypes, we are currently, for the first time, integrating functional genetics. Our results are providing some of the first insights into parasitic hijacking of animal behaviour.