Classification of trypanosomatids from insects and plants by the UP-PCR (Universally primed PCR) technique and cross dot blot hybridization of PCR products

For the first time the UP-PCR technique with its hybridization assay was ap plied to trypanosomatids isolated from insects and plants. 13 isolates of t rypanosomatids from insects (eight isolates from Russia, one from Czech Rep ublic and four reference cultures) and three plant isolates were analyzed. By the cross dot blot hybridization of UP-PCR products it was demonstrated that most trypanosomatids except for Wallaceina branch and two species of L eptomonas genera are quite distant from each other and the degree of relati onship cannot be resolved by PCR with random primers. The methods used allo wed segregation of all trypanosomatids tested into 12 separate genospecies (natural groups) with very different genomic structure. Wallaceina together with two others isolates and two Leptomonas formed separate groups. Theref ore, separate taxon status for Wallaceina and two Leptomonas species as wel l as heterogeneity of Leptomonas, Herpetomonas and Crithidia genera are pro posed. The low host specificity of insect trypanosomatids has been demonstr ated - two isolates of parasites from different insect orders are more simi lar than isolates from the same insect species. Isolation of occasional par asite or mixed parasite populations in laboratory culture is discussed. It may be proposed from the data obtained that the genera existing now do not reflect the real biodiversity of trypanosomatids and the current generic sy stematics of trypanosomatids have to be reviewed. Additional experiments in volving a large number of new isolates are necessary to resolve this proble m.