Leveraging the zombie-making strategies of Ophiocordyceps fungi to understand animal behaviour

Introduction

Reminiscent of zombies in pop culture, some parasites hijack host behaviours. Our understanding of this parasite strategy to improve transmission is minimal, despite its convergent evolution across major taxa. Functional genetics studies would advance our knowledge of the molecular underpinnings of “zombie behaviour.” Additionally, learning how behaviour can be altered would elucidate how “normal” phenotypes are maintained.

Challenges in Research

However, most zombie-making parasites and their hosts are not classic model organisms, which complicates mechanistic interrogation.

Case Study: Zombie Ants

The so-called “zombie ants” can be used to study parasite hijacking of animal behaviour in more detail. Zombie ants are infected by Ophiocordyceps fungi that cause summit disease. Infected ants ascend vegetation that they bite into as they die to ensure fungal spore dispersal.

Methodology Development

My lab developed fungal culturing techniques, infection methods, and behavioural assays to detail infection-related changes in daily ant foraging, communication, and locomotion. Additionally, by integrating multi-omics tools, we identified candidate fungal products and ant host pathways that might underlie the behavioural changes observed. However, to move from correlation to causation, these candidates need to be functionally tested.

Proposed Research

By leveraging my lab’s pioneering work and my training in molecular microbiology, I aim to elucidate the molecular genetics underlying parasite hijacking of host behaviour. I propose to:

1. Adopt molecular genetics tools to characterise fungal products that induce altered host behavioural phenotypes.
2. Use RNASeq and RNAi to investigate the affected ant pathways that give rise to those phenotypes.
3. Further establish the involvement of these behavioural pathways through integration of the animal model Drosophila melanogaster.

Impact of the Research

The proposed work will be transformative in our understanding of parasite manipulation strategies and spark novel research into sustainable pest control strategies and fungus-derived drugs.