Catalase is one of the most abundant enzymes on Earth. It decomposes hydrogen peroxide, thus protecting cells from dangerous reactive oxygen species. The catalase-encoding gene is conspicuously absent from the genome of most representatives of the family Trypanosomatidae. Here, we expressed this protein from the Leishmania mexicana Β-TUBULIN locus using a novel bicistronic expression system, which relies on the 2A peptide of Teschovirus A. We demonstrated that catalase-expressing parasites are severely compromised in their ability to develop in insects, to be transmitted and to infect mice, and to cause clinical manifestation in their mammalian host. Taken together, our data support the hypothesis that the presence of catalase is not compatible with the dixenous life cycle of Leishmania, resulting in loss of this gene from the genome during the evolution of these parasites.

• Klíčová slova
• Leishmania, catalase, dixeny, evolution, virulence,
• MeSH
• faktory virulence genetika   metabolismus   MeSH
• katalasa genetika   metabolismus   MeSH
• kultivované buňky MeSH
• Leishmania mexicana genetika   růst a vývoj   patogenita   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• protozoální proteiny genetika   MeSH
• Psychodidae parazitologie   MeSH
• stadia vývoje genetika   MeSH
• Teschovirus genetika   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• faktory virulence MeSH
• katalasa MeSH
• protozoální proteiny MeSH

Many high-quality genomes are available for dixenous (two hosts) trypanosomatid species of the genera Trypanosoma, Leishmania, and Phytomonas, but only fragmentary information is available for monoxenous (single-host) trypanosomatids. In trypanosomatids, monoxeny is ancestral to dixeny, thus it is anticipated that the genome sequences of the key monoxenous parasites will be instrumental for both understanding the origin of parasitism and the evolution of dixeny. Here, we present a high-quality genome for Leptomonas pyrrhocoris, which is closely related to the dixenous genus Leishmania. The L. pyrrhocoris genome (30.4 Mbp in 60 scaffolds) encodes 10,148 genes. Using the L. pyrrhocoris genome, we pinpointed genes gained in Leishmania. Among those genes, 20 genes with unknown function had expression patterns in the Leishmania mexicana life cycle suggesting their involvement in virulence. By combining differential expression data for L. mexicana, L. major and Leptomonas seymouri, we have identified several additional proteins potentially involved in virulence, including SpoU methylase and U3 small nucleolar ribonucleoprotein IMP3. The population genetics of L. pyrrhocoris was also addressed by sequencing thirteen strains of different geographic origin, allowing the identification of 1,318 genes under positive selection. This set of genes was significantly enriched in components of the cytoskeleton and the flagellum.

• MeSH
• druhová specificita MeSH
• energetický metabolismus genetika   MeSH
• fylogeneze MeSH
• genom protozoální genetika   MeSH
• genová ontologie MeSH
• Leishmania klasifikace   genetika   patogenita   MeSH
• molekulární evoluce * MeSH
• protozoální geny genetika   MeSH
• stanovení celkové genové exprese metody   MeSH
• Trypanosomatina klasifikace   genetika   patogenita   MeSH
• virulence genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Trypanosomes and leishmanias are widely known parasites of humans. However, they are just two out of several phylogenetic lineages that constitute the family Trypanosomatidae. Although dixeny - the ability to infect two hosts - is a derived trait of vertebrate-infecting parasites, the majority of trypanosomatids are monoxenous. Like their common ancestor, the monoxenous Trypanosomatidae are mostly parasites or commensals of insects. This review covers recent advances in the study of insect trypanosomatids, highlighting their diversity as well as genetic, morphological and biochemical complexity, which, until recently, was underappreciated. The investigation of insect trypanosomatids is providing an important foundation for understanding the origin and evolution of parasitism, including colonization of vertebrates and the appearance of human pathogens.

• Klíčová slova
• diversity, endosymbiosis, phylogeny, trypanosomatids, virus,
• MeSH
• biodiverzita MeSH
• biologická evoluce * MeSH
• hmyz parazitologie   MeSH
• interakce hostitele a parazita MeSH
• lidé MeSH
• Trypanosomatina klasifikace   genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH