Transcriptomic analysis validates the use of culture-derived Trypanosoma brucei and provides new markers for mammalian and insect life-cycle stages

RNA-Seq was performed on biological replicates of each life-cycle stage. These constitute the first datasets for culture-derived pleomorphic bloodstream forms and early and late procyclic forms. Expression profiles confirmed that genes known to be stage-regulated in the animal and insect hosts were also regulated in culture. Sequence reads of 100-125 bases provided sufficient precision to uncover differential expression of closely related genes. More than 100 transcripts showed peak expression in stumpy forms. Early and late procyclic forms showed differential expression of 74 transcripts, a number of which encoded proteins that were previously shown to be stage-regulated. Moreover, two adenylate cyclases previously shown to reduce social motility are up-regulated in late procyclic forms. This study validates the use of cultured bloodstream forms as an alternative to animal-derived parasites and yields new markers for all four stages. In addition to underpinning recent findings that early and late procyclic forms are distinct life-cycle stages, it could provide insights into the reasons for their different biological properties.