Abstract
Many microbes induce striking behavioral changes in their animal hosts, but how they achieve these effects is poorly understood, especially at the molecular level. This is due in large part to the lack of a robust system amenable to modern molecular manipulation. We recently discovered a strain of the behavior-manipulating fungal fly pathogen Entomophthora muscae infecting wild adult Drosophila in Northern California, and developed methods to reliably propagate the infection in lab.-reared Drosophila melanogaster. Our lab.- infected flies manifest the moribund behaviors characteristic of E. muscae infections: on their final day of life they climb to a high location, extend their proboscides and become affixed to the substrate, then finally raise their wings to strike a characteristic death pose that clears a path for spores that are forcibly ejected from their abdomen to land on and infect other flies. Using a combination of descriptive, histological, molecular and genomic techniques, we have carefully characterized the progress of infection in lab.-reared flies in both the fungus and host. Enticingly, we reveal that E. muscae invades the fly nervous system early in infection, suggesting a direct means by which the fungus could induce behavioral changes. Given the vast toolkit of molecular and neurobiological tools available for D. melanogaster, we believe this newly established E. muscae system will permit rapid progress in understanding how microbes manipulate animal behavior.
