Analyzing ambiguities in trypanosomatids taxonomy by barcoding

BACKGROUND: Biodiversity screens and phylogenetic studies are dependent on reliable DNA sequences in public databases. Biological collections possess vouchered specimens with a traceable history. Therefore, DNA sequencing of samples available at institutional collections can greatly contribute to taxonomy, and studies on evolution and biodiversity. METHODS: We sequenced part of the glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) and the SSU rRNA (V7/V8) genes from 102 trypanosomatid cultures, which are available on request at www.colprot.fiocruz.br. OBJECTIVE: The main objective of this work was to use phylogenetic inferences, using the obtained DNA sequences and those from representatives of all Trypanosomatidae genera, to generate phylogenetic trees that can simplify new isolates screenings. FINDINGS: A DNA sequence is provided for the first time for several isolates, the phylogenic analysis allowed the classification or reclassification of several specimens, identification of candidates for new genera and species, as well as the taxonomic validation of several deposits. MAIN CONCLUSIONS: This survey aimed at presenting a list of validated species and their associated DNA sequences combined with a short historical overview of each isolate, which can support taxonomic and biodiversity research and promote culture collections

Exploring the environmental diversity of kinetoplastid flagellates in the high-throughput DNA sequencing era

International audienceThe class Kinetoplastea encompasses both free-living and parasitic species from a wide range of hosts. Several representatives of this group are responsible for severe human diseases and for economic losses in agriculture and livestock. While this group encompasses over 30 genera, most of the available information has been derived from the vertebrate pathogenic genera Leishmania and Trypanosoma. Recent studies of the previously neglected groups of Kinetoplastea indicated that the actual diversity is much higher than previously thought. This article discusses the known segment of kinetoplastid diversity and how gene-directed Sanger sequencing and next-generation sequencing methods can help to deepen our knowledge of these interesting protists

Molecular mechanisms of thermal resistance of the insect trypanosomatid <i>Crithidia thermophila</i>

<div><p>In the present work, we investigated molecular mechanisms governing thermal resistance of a monoxenous trypanosomatid <i>Crithidia luciliae thermophila</i>, which we reclassified as a separate species <i>C</i>. <i>thermophila</i>. We analyzed morphology, growth kinetics, and transcriptomic profiles of flagellates cultivated at low (23°C) and elevated (34°C) temperature. When maintained at high temperature, they grew significantly faster, became shorter, with genes involved in sugar metabolism and mitochondrial stress protection significantly upregulated. Comparison with another thermoresistant monoxenous trypanosomatid, <i>Leptomonas seymouri</i>, revealed dramatic differences in transcription profiles of the two species with only few genes showing the same expression pattern. This disparity illustrates differences in the biology of these two parasites and distinct mechanisms of their thermotolerance, a prerequisite for living in warm-blooded vertebrates.</p></div

Molecular mechanisms of thermal resistance of the insect trypanosomatid Crithidia thermophila

In the present work, we investigated molecular mechanisms governing thermal resistance of a monoxenous trypanosomatid Crithidia luciliae thermophila, which we reclassified as a separate species C. thermophila. We analyzed morphology, growth kinetics, and transcriptomic profiles of flagellates cultivated at low (23°C) and elevated (34°C) temperature. When maintained at high temperature, they grew significantly faster, became shorter, with genes involved in sugar metabolism and mitochondrial stress protection significantly upregulated. Comparison with another thermoresistant monoxenous trypanosomatid, Leptomonas seymouri, revealed dramatic differences in transcription profiles of the two species with only few genes showing the same expression pattern. This disparity illustrates differences in the biology of these two parasites and distinct mechanisms of their thermotolerance, a prerequisite for living in warm-blooded vertebrates

Species, strains and isolates analyzed in this study.

<p>Species, strains and isolates analyzed in this study.</p

Light microscopy of the isolate COLPROT 054.

<p><b>(A)</b> Giemsa-stained pro- and choanomastigotes are shown. Differential interference contrast <b>(B)</b> and fluorescent <b>(C)</b> microscopy of the DAPI-stained slides demonstrate presence of the nucleus and kinetoplast. Scale bars are 2.5 μm.</p