Fred R. Opperdoes of the Christian de Duve Institute of Cellular Pathology in Belgium and his colleagues analyzed the genomes of two types of trypanosomatids, the group of bugs behind sleeping sickness, Chagas' disease and leishmaniasis. The team found that the genomes of Trypanosoma brucei (see image) and Leishmania mexicana contain 16 genes closely related to genes found in plants. The corresponding plant genes contribute to photosynthesis. Trypanosomatids lack the ability to photosynthesis but the scientists did detect proteins produced by these genes in the microbes' glycosomes, which help them extract energy from food. The researchers thus posit that a small algal organism used to live inside trypanosomatids, and was eliminated by evolution save for some of its genes.
The findings could point to new ways to combat parasitic diseases, the authors conclude, because the effects of a variety of agricultural herbicides on trypanosomes and leishmaniasis can easily be tested.