In our previous work we established a T7 polymerase-driven Tetracycline-inducible protein expression system in Leishmania mexicana (Biagi, 1953). We used this system to analyse gene expression profiles during development of L. mexicana in procyclic and metacyclic promastigotes and amastigotes. The transcription of the gene of interest and the T7 polymerase genes was significantly reduced upon cell differentiation. This regulation is not locus-specific. It depends on untranslated regions flanking open reading frames of the genes analysed. In this paper, we report that the previously established conventional inducible protein expression system may not be suitable for studies on differentiation of species of Leishmania Ross, 1903 and protein expression systems might have certain limitations., Aygul Ishemgulova, Natalya Kraeva, Drahomíra Faktorová, Lucie Podešvová, Julius Lukeš, Vyacheslav Yurchenko., and Obsahuje bibliografii
Four new species of monoxenous kinetoplastid parasites are described from Brachycera flies, namely Wallaceina raviniae Votýpka et Lukeš, 2014 and Crithidia otongatchiensis Votýpka et Lukeš, 2014 from Ecuador, Leptomonas moramango Votýpka et Lukeš, 2014 from Madagascar, and Crithidia pragensis Votýpka, Klepetková et Lukeš, 2014 from the Czech Republic. The new species are described here based on sequence analysis of their spliced leader (SL) RNA, glycosomal glyceraldehyde 3-phosphate dehydrogenase (gGAPDH) and small subunit (SSU) rRNA genes, as well as their morphology and ultrastructure. High-pressure freezing and Bernhard's EDTA regressive staining, used for the first time for monoxenous (one host) trypanosomatids, revealed the presence of viral particles with cytosolic localization in one and unique mitochondrial localization in another species. In accordance with previous observations, our results emphasize a discrepancy between morphology and molecular taxonomy of the family Trypanosomatidae. All four newly described species are represented by typical morphotypes (mainly choano- and promastigotes) and are virtually indistinguishable from other monoxenous trypanosomatids by morphology. Nevertheless, they all differ in their phylogenetic affinities. Whereas three of them grouped within the recently defined subfamily Leishmaniinae, which includes numerous representatives of the genera Leishmania Ross, 1903, Crithidia Léger, 1902 and Leptomonas Kent, 1880, the fourth species clusters together with the ''collosoma'' clade (named after ''Leptomonas'' collosoma Wallace, Clark, Dyer et Collins, 1960). Here we demonstrate that the ''collosoma'' group represents the elusive genus Wallaceina Podlipaev, Frolov et Kolesnikov, 1999. We redefine this genus in molecular terms based on similarities of the respective molecular markers and propose to use this taxon name for the group of species of the ''collosoma'' clade.