Abstract
AbstractCrithidia bombiis a trypanosomatid parasite that infects several species of bumble bees (Bombusspp.), by adhering to their intestinal tract.Crithidia bombiinfection impairs learning and reduces survival of workers and overwintering queens. Although there is extensive research on the ecology of this host-pathogen system, we understand far less about the mechanisms that mediate internal infection dynamics.Crithidia bombiinfects hosts by attaching to the hindgut via the flagellum, and one previous study found that a nectar secondary compound removed the flagellum, preventing attachment. However, approaches that allow more detailed observation of parasite attachment and growth would allow us to better understand factors mediating this host-pathogen relationship. We established techniques for genetic manipulation and visualization of culturedC. bombi. Using constructs established forCrithidia fasciculata, we successfully generatedC. bombicells expressing ectopic fluorescent transgenes using two different selectable markers. To our knowledge, this is the first genetic modification of this species. We also introduced constructs that label the mitochondrion and nucleus of the parasite, showing that subcellular targeting signals can function across parasite species to highlight specific organelles. Finally, we visualized fluorescently tagged parasitesin vitroin both their swimming and attached forms, andin vivoin bumble bee (Bombus impatiens) hosts. Expanding our cell and molecular toolkit forC. bombiwill help us better understand how factors such as host diet, immune system, and physiology mediate outcomes of infection by these common parasites.
Publisher
Cold Spring Harbor Laboratory