Meeting Abstract

S7.3-3  Monday, Jan. 6 14:30  Heterogeneous mechanisms underlying behavioral manipulation by a fungal parasite DE BEKKER, C.*; QUEVILLON, L.E.; SMITH, P.B.; PATTERSON, A.D.; HUGHES, D.P.; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University c.debekker@psu.edu

Parasite-host co-evolution has driven parasites to evolve strategies to invade, overcome the immune system, and exploit their hosts for their own survival and dispersal. Some parasites also interact with the host’s nervous system, changing behavior. One of the most dramatic examples is the fungus Ophiocordyceps unilateralis s.l. infecting Camponotus species, where ants bite into vegetation before dying to facilitate spore dispersal. To establish this, the fungus not only overcomes the immune system, but also manipulates the brain and atrophies the muscles. We recently succeeded in moving this model system into the lab, allowing us to start unraveling the proximate mechanisms underlying this phenomenon. By combining metabolite profiling with ex vivo insect tissue culturing, compounds secreted in different areas of the host were studied. Using this technique we established that generalist and specialist fungal entomopathogens react differently to the same insect tissues. Next to that, these entomopathogens react heterogeneously to brain and muscle tissue by secreting a significantly different array of metabolites. Furthermore, about 70% of the metabolites O. unilateralis significantly employs when presented with brains differ when they are derived from different ant species. This is in line with infection studies performed under laboratory conditions: while some ant species display the manipulated biting behavior prior to death, other species do not. As part of this interdisciplinary dataset, we also identified two metabolites that are possibly involved in establishing manipulation. We are now developing the protocols to move towards fungal gene expression of cells surrounding ant brains during manipulated biting behavior.