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- Fagundes Macedo, Diego, et al.
(författare)
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Diversity of RNA viruses in the cosmopolitan monoxenous trypanosomatid Leptomonas pyrrhocoris
- 2023
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Ingår i: BMC Biology. - 1741-7007. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Trypanosomatids are parasitic flagellates well known because of some representatives infecting humans, domestic animals, and cultural plants. Many trypanosomatid species bear RNA viruses, which, in the case of human pathogens Leishmania spp., influence the course of the disease. One of the close relatives of leishmaniae, Leptomonas pyrrhocoris, has been previously shown to harbor viruses of the groups not documented in other trypanosomatids. At the same time, this species has a worldwide distribution and high prevalence in the natural populations of its cosmopolitan firebug host. It therefore represents an attractive model to study the diversity of RNA viruses.Results We surveyed 106 axenic cultures of L. pyrrhocoris and found that 64 (60%) of these displayed 2-12 double-stranded RNA fragments. The analysis of next-generation sequencing data revealed four viral groups with seven species, of which up to five were simultaneously detected in a single trypanosomatid isolate. Only two of these species, a tombus-like virus and an Ostravirus, were earlier documented in L. pyrrhocoris. In addition, there were four new species of Leishbuviridae, the family encompassing trypanosomatid-specific viruses, and a new species of Qinviridae, the family previously known only from metatranscriptomes of invertebrates. Currently, this is the only qinvirus with an unambiguously determined host. Our phylogenetic inferences suggest reassortment in the tombus-like virus owing to the interaction of different trypanosomatid strains. Two of the new Leishbuviridae members branch early on the phylogenetic tree of this family and display intermediate stages of genomic segment reduction between insect Phenuiviridae and crown Leishbuviridae.Conclusions The unprecedented wide range of viruses in one protist species and the simultaneous presence of up to five viral species in a single Leptomonas pyrrhocoris isolate indicate the uniqueness of this flagellate. This is likely determined by the peculiarity of its firebug host, a highly abundant cosmopolitan species with several habits ensuring wide distribution and profuseness of L. pyrrhocoris, as well as its exposure to a wider spectrum of viruses compared to other trypanosomatids combined with a limited ability to transmit these viruses to its relatives. Thus, L. pyrrhocoris represents a suitable model to study the adoption of new viruses and their relationships with a protist host.
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| 2. |
- Mohammed, Mubasher, Msc, et al.
(författare)
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Single-cell transcriptomics reveals transcriptional programs underlying male and female cell fate during Plasmodium falciparum gametocytogenesis
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The Apicomplexa constitute a large phylum of parasitic protozoa with complex life cycles that typically include meiotic sex. The life cycle of the malaria parasite, Plasmodium falciparum, includes obligate transition and stage development between a human and mosquito host. Asexual parasite replication in the human erythrocytes is followed by differentiation which leads to the formation of a precursor gamete stage, referred to as gametocytes. The gametocyte stage is solely responsible for malaria transmission into the mosquito vector where gamete fusion followed by meiosis occurs. How the parasite differentiates into male and female gametocytes in the absence of sex chromosomes largely remains an open question. Here we combine FACS-based cell enrichment of a gametocyte reporter line followed by single-cell RNA-seq, to enable targeted characterization of the entire gametocyte developmental stage. Our data defines differential transcriptional programs during male and female gametocyte development and highlights a bifurcation point for sexual cell fate. We perform prediction analyses of novel candidate driver genes underlying P. falciparum male and female lineage development. Our data indicate that a large panel of genes linked to the inner membrane complex, known to be involved in morphological life cycle changes, appears to be uniquely expressed in the female gametocyte lineage. Additionally, we delineate the timing of expression of members of the ApiAP2 family of transcription factors and predict their specificity in male and female P. falciparum gametocyte development. A motif-driven gene regulatory network analysis indicates a major role for AP2-G5 in downstream gene regulation along the male lineage developmental trajectory. In total, we anticipate that this study provides the malaria community with an important resource for the development of transmission-blocking intervention strategies.
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