DeMarco, Stephanie

Stephanie is in the Immunity, Microbes & Molecular Pathogenesis home area of the MBIDP.  She joined the CMB training program in 2015.  Her research mentor is Dr. Kent Hill.  She received a B.A. degree in 2013 from UC Berkeley.

Mentor: Dr. Kent Hill

Research project:

Microbial social behavior greatly influences life on earth, from nutrient cycling to microbial pathogenesis.  The Hill lab recently discovered a novel social behavior in the tsetse-fly transmission stage of the protozoan parasite, Trypanosoma brucei.  T. brucei is the causative agent of sleeping sickness in humans and related diseases in animals in sub-Saharan Africa.  While normally considered as individual cells and studied in suspension cultures, in their natural environment, the parasites live and move on tissue surfaces within their insect vector.  When cultivated on semi-solid surfaces, individual T. brucei parasites actively assemble into groups of cells that coordinate their movements to eventually form one large group.  A subset of cells then decide to migrate radially away from the group, forming projections of parasites.  Previous work in the lab has shown that T. brucei social motility is mediated by cAMP signaling systems in the parasite flagellum.  Loss of a subset of receptor-type adenylate cyclases, localized along the surface of the flagellar membrane, results in a hypersocial phenotype where many more projections are made.  However, when a cAMP-specific phosphodiesterase is knocked down, the cells do not form any projections.  My research focuses on further elucidating the molecular mechanism of T. brucei social motility and identifying novel regulators of this process.