Beyond Blood: African Trypanosomes on the Move.

While the African trypanosomes are among the best-studied parasites, almost everything we know about them is based on the brucei group, which includes the human-infective sleeping sickness parasites and the causative agent of the cattle plague nagana. The past decades have seen an ever-more detailed molecular dissection of Trypanosoma brucei, which today is an accepted cell biological model system. Therefore, recent work on some fundamental aspects of trypanosome biology surprises, as we realise that our knowledge about parasite motility and tropism in the changing host microenvironments is far from definitive. In this review, we highlight a few examples of neglected parasitological questions, which may open (or reopen) a new chapter of trypanosome research.