The diversity of insect and plant trypanosomatids: molecular (PCR) and morphology data

The most unreliable part in the taxonomic system of the trypanosomatids is the domain of trypanosomatids from insects and plants. The relationships within insect trypanosomatids are still obscure. Twenty-two isolates from insects (both reference strains and recent isolates) and four isolates from plants were, investigated by RAPD, UP-PCR and cross dot-blot hybridization of UP-PCR products. Ultrastructure and some additional characters (polymorphism of colonies on solid medium, DNA content by flow cytometry etc.) were also examined. It was concluded that: I. The main clusters on dendrograms derived from PCR are supported by ultrastructural data; 2. Leptomonas-like isolates are very heterogeneous by all methods used thus confirming the view of Leptomonas as an artificial group; 3. The number of current genera of trypanosomatids is not enough to demonstrate the real diversity of these parasites and new genera have to be established. (Résumé d'auteur