Soil-transmitted parasitic worms infect over a billion people, primarily in the world’s most socioeconomically disadvantaged communities, causing devastating and sometimes fatal illness. Despite this massive health burden, we lack basic knowledge about the neural adaptations that enable parasitic worms to locate and infect human hosts. Although they exhibit unique host-seeking behaviors, including robust attraction to mammalian body heat, the nervous systems of parasitic worms are quite similar to those of the non-parasitic nematode C. elegans. Our goal is to leverage the wealth of knowledge about C. elegans to identify the specific molecular and neural adaptations that shape the unique thermosensory behaviors of parasitic nematodes.

I have developed Strongyloides stercoralis, a human parasite that infects around 680 million people and can be fatal, as a powerful new model for performing mechanistic studies of human parasitism and the evolution of sensory behaviors. We combine phylogenetic comparisons, CRISPR/Cas9 mutagenesis pipelines, neural imaging, and ectopic expression strategies to identify the molecular and cellular substrates of parasite-specific thermosensory responses across evolutionarily distinct nematode lineages. Our results provide insight into how common sensory abilities, such as temperature-driven host seeking, evolved multiple times independently in nematodes; a first step towards designing novel and broadly effective anti-parasitic drugs capable of disrupting infections.