I’ve written about mind-controlling parasites and I’ve also written about ants a couple of times, but for some reason I still haven’t written about the famous “zombie ants“. These fascinating, macabre little wonders are ants that have been infected by a fungus (Ophiocordyceps unilateralis) which manipulates their behaviour. The fungus makes the ant climb up at plant stalk and bite into the underside of a leaf, clinging to it in a death grip. The fungus then kills the ant, consuming its innards before sending a reproductive stalk out through the corpse’s head.
I recently found out about an exciting research project looking into how the fungus manages its manipulation of the ant. Charissa de Bekker, a post-doc at Penn State University, is using Microryza to crowdfund her project, which will investigate what genes are active in the fungus’ manipulation of the ant. Since I think it’s an awesome project, I invited her to answer a few questions about herself and her work. Read on to find out what she has to say, and if you think the project sounds interesting or useful, consider backing it on Microryza — she’s got 11 days left to reach her goal!
Could you briefly introduce yourself and tell us about your research project?
My name is Charissa de Bekker and I am from the Netherlands. That’s where I studied biology, did a Master’s in Biomolecular Sciences and finally went on to obtain a PhD Degree in Biology. After my PhD, I moved to Pennsylvania to start working on Ophiocordyceps fungi that are parasites of ants and as part of their life cycle manipulate the behavior of their hosts. In our lab (at PSU) we make use of various disciplines to study this phenomenon ranging from field biology, to behavioral ecology to molecular microbiology. It’s so much fun to work in a lab in which we all have different scientific backgrounds and interests! Coming from the field of fungal genetics, I have been developing tools and techniques to study this system from the parasite’s point of view in controlled laboratory conditions. Now, for my Microryza project I want to start looking at the Ophiocrodyceps genes that are involved in the manipulated biting behavior we see in infected ants right before they die. I aim to do this by making sections of the heads of infected ants and use laser capture microdissection to cut out the fungal cells that are manipulating the brain tissue. From these cells I will isolate the RNA for analysis to discover which genes are of importance.
How did you get interested in Cordyceps and what do you find exciting about it?
During my college years I became more and more interested in microbes (especially fungi) and the biotechnological approaches researchers employ to study them and make them useful in all kinds of applications. Microbes are generally seen as these lower forms of life, but can they can do very complex things. The theme of my PhD was therefore to show how complex even “boring” molds grown in a petri dish can be and how their cells can be very heterogeneous in their gene expression. For someone interested in fungal complexity parasites are, of course, even more interesting, since they have to go through different phases of infection and deal with the different tissues in their host. It was during my PhD I learned about the different Cordyceps species and how some of them are able to not only infect their hosts, but also do something as remarkably complex as manipulating their behavior. This just blew my mind so when I (by coincidence actually) met David Hughes, who has extensively studied this phenomenon in the field, I decided to go work with him when he offered me a postdoc position. Now in his lab I am making the first strides into figuring out the mechanisms underlying this phenomenon by studying how these fungi heterogeneously deal with the different tissues they encounter within their hosts. It’s very exciting, since we know so little about this system or about other parasite-host interactions in which behavioral manipulation plays an important role in transmission.
Can you share any of the results you’ve found so far to whet people’s appetite?
Studying the interactions between parasites and their hosts is a difficult thing to do, so we developed a technique in which we are able to look at how fungal insect pathogens react to different ant tissues ex vivo. In short, we separate and keep ant tissues alive outside of the ant’s body and grow the fungus next to it to measure the metabolites the fungus secretes as a reaction to these different tissues. This way we were able to identify novel cyclic depsipeptides, for instance, which are killing compounds made by fungal insect pathogens. These compounds are fairly well studied for the species Beauveria and Metarhizium but with our new approach we were able to report a couple of new ones (in this PLoS ONE paper from 2013). We are now using this technique as well for Ophiocordyceps and found some interesting looking metabolites.
Why did you decide to use Microryza for funding?
From a financial perspective: since this system is still in its early stages, as is the field of parasitic brain manipulation, it is hard to persuade bigger funding programs to fund our projects with budgets getting tighter and therefore more people applying for the same bag of money. Trying to crowdfund a smaller project, like the one I am campaigning for, to get the very valuable first datasets that will prove that this system really has a wealth of information to offer will thus improve our chances to fund the bigger picture as well. Next to that, this dataset will be immensely informative for future hypotheses and projects.
Next to that, I have to say crowdfunding is a great way to reach the people out there that are interested in our work. Not only other researchers, but also teachers and general science enthusiasts. You of course reach those people by publishing open access papers but in those papers the language is more formal. Science journalists and bloggers fill in that gap really well by reporting about the research they think is interesting. This is also how I educate myself about other fields in the first place (going to the actual research paper next if something really grabbed my interest). However, people still don’t get to see to process behind the publication. Microryza provides the possibility to keep your backers up to date through online lab notes so you can tell people about the progress you are making to get to your research goal. And it can be more interactive. Questions can be asked and comments can be made. These are also very important reasons for me to try and get my project funded through the crowd.
I also find Cordyceps really fascinating, which was enough to make me want to back your project. What would say to someone who was more concerned with practical benefits? What do we gain from learning about fungi that manipulate ants?
One of the reasons for studying this interesting parasite-host interaction is the useful applications it harbors. Next to this research just being fascinating, we expect to find compounds that are interesting for medicine. In fact, the (Ophio)cordyceps fungi are famous for the medicinally interesting compounds they secrete. For example, Cyclosporin A is a drug used to help prevent rejection of transplanted organs and was originally isolated from the fungus Tolypocladium inflatum, which is closely related to the fungi we study since it is within the same family. Also, if we learn more about how parasites change behavior we could apply this in neuromedicine approaches. In fact, if we knew how these parasites co-opt behavioral plasticity of their host, we could learn more about how behavior is regulated chemically in general. The first data (which is the data we are generating right now together with the important data generated in the Microryza project) will push us in the right direction with this.
Last but not least, the insect infecting fungi are widely used in natural pest control applications. By learning more about the brain manipulating species, we will thus learn if these fungi might be good candidates for those type of applications as well.