Authors

Discussion

Trypanosoma carassii is a freshwater fish parasite that infects a variety of cyprinids (carp family). The prevalence approaches 100% in densely populated fish farms. Here, the procedures for long term culture and transgenesis of T. carassii are described as the first step in developing a model to study host-pathogen interaction in zebrafish. We show that T. carassii can be genetically modified using approaches developed in T. brucei and these have been used to make T. carassii cell lines expressing mNeonGreen and Ruby fluorescent protein transgenes driven by either RNA pol II, RNA pol I and T7 polymerase. These cell lines have been used to infect transparent zebrafish larvae, facilitating the tracking of all trypanosomes infecting a host. The infection in zebrafish larvae has been followed by fluorescence quantification and the distribution by fluorescence microscopy over the course of an infection.