scholarly journals De novo profiling of RNA viruses in Anopheles malaria vector mosquitoes from forest ecological zones in Senegal and Cambodia

2018 ◽  
Author(s):  
Eugeni Belda ◽  
Ferdinand Nanfack Minkeu ◽  
Karin Eiglmeier ◽  
Guillaume Carissimo ◽  
Inge Holm ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Small Rna ◽  
De Novo ◽  
Rna Viruses ◽  
Sequence Similarity ◽  
Anopheles Coluzzii ◽  
Anopheles Dirus ◽  
Virus Family ◽  
Human Malaria ◽  
Redundant Contigs

AbstractBackgroundMosquitoes are colonized by a large but mostly uncharacterized natural virome of RNA viruses. Anopheles mosquitoes are efficient vectors of human malaria, and the composition and distribution of the natural RNA virome may influence the biology and immunity of Anopheles malaria vector populations.ResultsAnopheles vectors of human malaria were sampled in forest village sites in Senegal and Cambodia, including Anopheles funestus, Anopheles gambiae group sp., and Anopheles coustani in Senegal, and Anopheles hyrcanus group sp., Anopheles maculatus group sp., and Anopheles dirus in Cambodia. Small and long RNA sequences were depleted of mosquito host and de novo assembled to yield non-redundant contigs longer than 500 nucleotides. Analysis of the assemblies by sequence similarity to known virus families yielded 125 novel virus sequences, 39 from Senegal Anopheles and 86 from Cambodia. Important monophyletic virus clades in the Bunyavirales and Mononegavirales orders are found in these Anopheles from Africa and Asia. Small RNA size and abundance profiles were used to cluster non-host RNA assemblies that were unclassified by sequence similarity. 39 unclassified non-redundant contigs >500 nucleotides strongly matched a pattern of classic RNAi processing of viral replication intermediates, and 1566 unclassified contigs strongly matched a pattern consistent with piRNAs. Analysis of piRNA expression in Anopheles coluzzii after infection with O’nyong nyong virus (family Togaviridae) suggests that virus infection can specifically alter abundance of some piRNAs.ConclusionsRNA viruses ubiquitously colonize Anopheles vectors of human malaria worldwide. At least some members of the mosquito virome are monophyletic with other arthropod viruses. However, high levels of collinearity and similarity of Anopheles viruses at the peptide level is not necessarily matched by similarity at the nucleotide level, indicating that Anopheles from Africa and Asia are colonized by closely related but clearly diverged virome members. The interplay between small RNA pathways and the virome may represent an important part of the homeostatic mechanism maintaining virome members in a commensal or nonpathogenic state, and host-virome interactions could influence variation in malaria vector competence.

scholarly journals Salivary gland proteins of the human malaria vector, Anopheles dirus B (Diptera: Culicidae)

2007 ◽  
Vol 49 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Narissara Jariyapan ◽  
Wej Choochote ◽  
Atchariya Jitpakdi ◽  
Thasaneeya Harnnoi ◽  
Padet Siriyasatein ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Malaria Vector ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Specific Protein ◽  
Proximal Region ◽  
Differential Distribution ◽  
Anopheles Dirus ◽  
Human Malaria

Salivary gland proteins of the human malaria vector, Anopheles dirus B were determined and analyzed. The amount of salivary gland proteins in mosquitoes aged between 3 - 10 days was approximately 1.08 ± 0.04 µg/female and 0.1 ± 0.05 µg/male. The salivary glands of both sexes displayed the same morphological organization as that of other anopheline mosquitoes. In females, apyrase accumulated in the distal regions, whereas alpha-glucosidase was found in the proximal region of the lateral lobes. This differential distribution of the analyzed enzymes reflects specialization of different regions for sugar and blood feeding. SDS-PAGE analysis revealed that at least seven major proteins were found in the female salivary glands, of which each morphological region contained different major proteins. Similar electrophoretic protein profiles were detected comparing unfed and blood-fed mosquitoes, suggesting that there is no specific protein induced by blood. Two-dimensional polyacrylamide gel analysis showed the most abundant salivary gland protein, with a molecular mass of approximately 35 kilodaltons and an isoelectric point of approximately 4.0. These results provide basic information that would lead to further study on the role of salivary proteins of An. dirus B in disease transmission and hematophagy.

scholarly journals De novo profiling of RNA viruses in Anopheles malaria vector mosquitoes from forest ecological zones in Senegal and Cambodia

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Eugeni Belda ◽  
Ferdinand Nanfack-Minkeu ◽  
Karin Eiglmeier ◽  
Guillaume Carissimo ◽  
Inge Holm ◽  
...  
Keyword(s):  
Malaria Vector ◽  
De Novo ◽  
Rna Viruses ◽  
Ecological Zones

scholarly journals Correction to: De novo profiling of RNA viruses in Anopheles malaria vector mosquitoes from forest ecological zones in Senegal and Cambodia

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Eugeni Belda ◽  
Ferdinand Nanfack-Minkeu ◽  
Karin Eiglmeier ◽  
Guillaume Carissimo ◽  
Inge Holm ◽  
...  
Keyword(s):  
Malaria Vector ◽  
De Novo ◽  
Rna Viruses ◽  
Ecological Zones

scholarly journals Comprehensive Ecological and Geographic Characterization of Eukaryotic and Prokaryotic Microbiomes in African Anopheles

2021 ◽  
Vol 12 ◽  
Author(s):  
Eugeni Belda Cuesta ◽  
Boubacar Coulibaly ◽  
Tullu Bukhari ◽  
Karin Eiglmeier ◽  
Raymond Kone ◽  
...  
Keyword(s):  
Species Richness ◽  
West Africa ◽  
De Novo ◽  
Sequence Similarity ◽  
Pathogen Transmission ◽  
Anopheles Coluzzii ◽  
Taxonomic Assignment ◽  
Breeding Sites ◽  
Microbiome Composition ◽  
Laboratory Colonies

Exposure of mosquitoes to numerous eukaryotic and prokaryotic microbes in their associated microbiomes has probably helped drive the evolution of the innate immune system. To our knowledge, a metagenomic catalog of the eukaryotic microbiome has not been reported from any insect. Here we employ a novel approach to preferentially deplete host 18S ribosomal RNA gene amplicons to reveal the composition of the eukaryotic microbial communities of Anopheles larvae sampled in Kenya, Burkina Faso and Republic of Guinea (Conakry). We identified 453 eukaryotic operational taxonomic units (OTUs) associated with Anopheles larvae in nature, but an average of 45% of the 18S rRNA sequences clustered into OTUs that lacked a taxonomic assignment in the Silva database. Thus, the Anopheles microbiome contains a striking proportion of novel eukaryotic taxa. Using sequence similarity matching and de novo phylogenetic placement, the fraction of unassigned sequences was reduced to an average of 4%, and many unclassified OTUs were assigned as relatives of known taxa. A novel taxon of the genus Ophryocystis in the phylum Apicomplexa (which also includes Plasmodium) is widespread in Anopheles larvae from East and West Africa. Notably, Ophryocystis is present at fluctuating abundance among larval breeding sites, consistent with the expected pattern of an epidemic pathogen. Species richness of the eukaryotic microbiome was not significantly different across sites from East to West Africa, while species richness of the prokaryotic microbiome was significantly lower in West Africa. Laboratory colonies of Anopheles coluzzii harbor 26 eukaryotic OTUs, of which 38% (n = 10) are shared with wild populations, while 16 OTUs are unique to the laboratory colonies. Genetically distinct An. coluzzii colonies co-housed in the same facility maintain different prokaryotic microbiome profiles, suggesting a persistent host genetic influence on microbiome composition. These results provide a foundation to understand the role of the Anopheles eukaryotic microbiome in vector immunity and pathogen transmission. We hypothesize that prevalent apicomplexans such as Ophryocystis associated with Anopheles could induce interference or competition against Plasmodium within the vector. This and other members of the eukaryotic microbiome may offer candidates for new vector control tools.

scholarly journals Interaction of RNA viruses of the natural virome with the African malaria vector, Anopheles coluzzii

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ferdinand Nanfack-Minkeu ◽  
Christian Mitri ◽  
Emmanuel Bischoff ◽  
Eugeni Belda ◽  
Isabelle Casademont ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Rna Viruses ◽  
Anopheles Coluzzii

scholarly journals Structure Unveils Relationships between RNA Virus Polymerases

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 313
Author(s):  
Heli A. M. Mönttinen ◽  
Janne J. Ravantti ◽  
Minna M. Poranen
Keyword(s):  
Phylogenetic Tree ◽  
Rna Viruses ◽  
Rna Virus ◽  
Sequence Similarity ◽  
Protein Structures ◽  
Structural Similarity ◽  
Functional Differentiation ◽  
Comparison Method ◽  
Homologous Structure ◽  
Biological Entities

RNA viruses are the fastest evolving known biological entities. Consequently, the sequence similarity between homologous viral proteins disappears quickly, limiting the usability of traditional sequence-based phylogenetic methods in the reconstruction of relationships and evolutionary history among RNA viruses. Protein structures, however, typically evolve more slowly than sequences, and structural similarity can still be evident, when no sequence similarity can be detected. Here, we used an automated structural comparison method, homologous structure finder, for comprehensive comparisons of viral RNA-dependent RNA polymerases (RdRps). We identified a common structural core of 231 residues for all the structurally characterized viral RdRps, covering segmented and non-segmented negative-sense, positive-sense, and double-stranded RNA viruses infecting both prokaryotic and eukaryotic hosts. The grouping and branching of the viral RdRps in the structure-based phylogenetic tree follow their functional differentiation. The RdRps using protein primer, RNA primer, or self-priming mechanisms have evolved independently of each other, and the RdRps cluster into two large branches based on the used transcription mechanism. The structure-based distance tree presented here follows the recently established RdRp-based RNA virus classification at genus, subfamily, family, order, class and subphylum ranks. However, the topology of our phylogenetic tree suggests an alternative phylum level organization.

scholarly journals Transcriptomic and Proteomic Analyses Reveal the Diversity of Venom Components from the Vaejovid Scorpion Serradigitus gertschi

Toxins ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 359 ◽  
Author(s):  
Maria Romero-Gutiérrez ◽  
Carlos Santibáñez-López ◽  
Juana Jiménez-Vargas ◽  
Cesar Batista ◽  
Ernesto Ortiz ◽  
...  
Keyword(s):  
Serine Proteases ◽  
De Novo ◽  
Sequence Similarity ◽  
Scorpion Venom ◽  
Secretory Proteins ◽  
Host Defense Peptides ◽  
The Family ◽  
Pathogenesis Related ◽  
Molecular Masses

To understand the diversity of scorpion venom, RNA from venomous glands from a sawfinger scorpion, Serradigitus gertschi, of the family Vaejovidae, was extracted and used for transcriptomic analysis. A total of 84,835 transcripts were assembled after Illumina sequencing. From those, 119 transcripts were annotated and found to putatively code for peptides or proteins that share sequence similarities with the previously reported venom components of other species. In accordance with sequence similarity, the transcripts were classified as potentially coding for 37 ion channel toxins; 17 host defense peptides; 28 enzymes, including phospholipases, hyaluronidases, metalloproteases, and serine proteases; nine protease inhibitor-like peptides; 10 peptides of the cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 protein superfamily; seven La1-like peptides; and 11 sequences classified as “other venom components”. A mass fingerprint performed by mass spectrometry identified 204 components with molecular masses varying from 444.26 Da to 12,432.80 Da, plus several higher molecular weight proteins whose precise masses were not determined. The LC-MS/MS analysis of a tryptic digestion of the soluble venom resulted in the de novo determination of 16,840 peptide sequences, 24 of which matched sequences predicted from the translated transcriptome. The database presented here increases our general knowledge of the biodiversity of venom components from neglected non-buthid scorpions.

scholarly journals Microbial Functional Responses to Cholesterol Catabolism in Denitrifying Sludge

mSystems ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Sean Ting-Shyang Wei ◽  
Yu-Wei Wu ◽  
Tzong-Huei Lee ◽  
Yi-Shiang Huang ◽  
Cheng-Yu Yang ◽  
...  
Keyword(s):  
16S Rrna ◽  
De Novo ◽  
Anthropogenic Impacts ◽  
Sequence Similarity ◽  
Community Level ◽  
Model Organisms ◽  
Substrate Uptake ◽  
Functional Responses ◽  
Content Type ◽  
Rare Biosphere

ABSTRACTThe 2,3-secopathway, the pathway for anaerobic cholesterol degradation, has been established in the denitrifying betaproteobacteriumSterolibacterium denitrificans. However, knowledge of how microorganisms respond to cholesterol at the community level is elusive. Here, we applied mesocosm incubation and 16S rRNA sequencing to reveal that, in denitrifying sludge communities, three betaproteobacterial operational taxonomic units (OTUs) with low (94% to 95%) 16S rRNA sequence similarity toStl. denitrificansare cholesterol degraders and members of the rare biosphere. Metatranscriptomic and metabolite analyses show that these degraders adopt the 2,3-secopathway to sequentially catalyze the side chain and sterane of cholesterol and that two molybdoenzymes—steroid C25 dehydrogenase and 1-testosterone dehydrogenase/hydratase—are crucial for these bioprocesses, respectively. The metatranscriptome further suggests that these betaproteobacterial degraders display chemotaxis and motility toward cholesterol and that FadL-like transporters may be the key components for substrate uptake. Also, these betaproteobacteria are capable of transporting micronutrients and synthesizing cofactors essential for cellular metabolism and cholesterol degradation; however, the required cobalamin is possibly provided by cobalamin-de novo-synthesizing gamma-, delta-, and betaproteobacteria via the salvage pathway. Overall, our results indicate that the ability to degrade cholesterol in sludge communities is reserved for certain rare biosphere members and that C25 dehydrogenase can serve as a biomarker for sterol degradation in anoxic environments.IMPORTANCESteroids are ubiquitous and abundant natural compounds that display recalcitrance. Biodegradation via sludge communities in wastewater treatment plants is the primary removal process for steroids. To date, compared to studies for aerobic steroid degradation, the knowledge of anaerobic degradation of steroids has been based on only a few model organisms. Due to the increase of anthropogenic impacts, steroid inputs may affect microbial diversity and functioning in ecosystems. Here, we first investigated microbial functional responses to cholesterol, the most abundant steroid in sludge, at the community level. Our metagenomic and metatranscriptomic analyses revealed that the capacities for cholesterol approach, uptake, and degradation are unique traits of certain low-abundance betaproteobacteria, indicating the importance of the rare biosphere in bioremediation. Apparent expression of genes involved in cofactorde novosynthesis and salvage pathways suggests that these micronutrients play important roles for cholesterol degradation in sludge communities.

scholarly journals Structure of SPH (self-incompatibility protein homologue) proteins: a widespread family of small, highly stable, secreted proteins

2019 ◽  
Vol 476 (5) ◽  
pp. 809-826
Author(s):  
Karthik V. Rajasekar ◽  
Shuangxi Ji ◽  
Rachel J. Coulthard ◽  
Jon P. Ride ◽  
Gillian L. Reynolds ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Analytical Ultracentrifugation ◽  
De Novo ◽  
Learning Algorithm ◽  
Sequence Similarity ◽  
Homology Modelling ◽  
3D Structure ◽  
Large Family ◽  
Secreted Proteins ◽  
Self Incompatibility

Abstract SPH (self-incompatibility protein homologue) proteins are a large family of small, disulfide-bonded, secreted proteins, initially found in the self-incompatibility response in the field poppy (Papaver rhoeas), but now known to be widely distributed in plants, many containing multiple members of this protein family. Using the Origami strain of Escherichia coli, we expressed one member of this family, SPH15 from Arabidopsis thaliana, as a folded thioredoxin fusion protein and purified it from the cytosol. The fusion protein was cleaved and characterised by analytical ultracentrifugation, circular dichroism and nuclear magnetic resonance (NMR) spectroscopy. This showed that SPH15 is monomeric and temperature stable, with a β-sandwich structure. The four strands in each sheet have the same topology as the unrelated proteins: human transthyretin, bacterial TssJ and pneumolysin, with no discernible sequence similarity. The NMR-derived structure was compared with a de novo model, made using a new deep learning algorithm based on co-evolution/correlated mutations, DeepCDPred, validating the method. The DeepCDPred de novo method and homology modelling to SPH15 were then both used to derive models of the 3D structure of the three known PrsS proteins from P. rhoeas, which have only 15–18% sequence homology to SPH15. The DeepCDPred method gave models with lower discreet optimised protein energy scores than the homology models. Three loops at one end of the poppy structures are postulated to interact with their respective pollen receptors to instigate programmed cell death in pollen tubes.

scholarly journals A Novel Bipartite Double-Stranded RNA Mycovirus from the White Root Rot Fungus Rosellinia necatrix: Molecular and Biological Characterization, Taxonomic Considerations, and Potential for Biological Control

2009 ◽  
Vol 83 (24) ◽  
pp. 12801-12812 ◽  
Author(s):  
Sotaro Chiba ◽  
Lakha Salaipeth ◽  
Yu-Hsin Lin ◽  
Atsuko Sasaki ◽  
Satoko Kanematsu ◽  
...  
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Sequence Similarity ◽  
Peptide Mass Fingerprinting ◽  
Dsrna Virus ◽  
Rosellinia Necatrix ◽  
Virus Family ◽  
White Root Rot ◽  
Double Stranded Rna ◽  
Peptide Mass

ABSTRACT White root rot, caused by the ascomycete Rosellinia necatrix, is a devastating disease worldwide, particularly in fruit trees in Japan. Here we report on the biological and molecular properties of a novel bipartite double-stranded RNA (dsRNA) virus encompassing dsRNA-1 (8,931 bp) and dsRNA-2 (7,180 bp), which was isolated from a field strain of R. necatrix, W779. Besides the strictly conserved 5′ (24 nt) and 3′ (8 nt) terminal sequences, both segments show high levels of sequence similarity in the long 5′ untranslated region of approximately 1.6 kbp. dsRNA-1 and -2 each possess two open reading frames (ORFs) named ORF1 to -4. Although the protein encoded by 3′-proximal ORF2 on dsRNA-1 shows sequence identities of 22 to 32% with RNA-dependent RNA polymerases from members of the families Totiviridae and Chrysoviridae, the remaining three virus-encoded proteins lack sequence similarities with any reported mycovirus proteins. Phylogenetic analysis showed that the W779 virus belongs to a separate clade distinct from those of other known mycoviruses. Purified virions ∼50 nm in diameter consisted of dsRNA-1 and -2 and a single major capsid protein of 135 kDa, which was shown by peptide mass fingerprinting to be encoded by dsRNA-1 ORF1. We developed a transfection protocol using purified virions to show that the virus was responsible for reduction of virulence and mycelial growth in several host strains. These combined results indicate that the W779 virus is a novel bipartite dsRNA virus with potential for biological control (virocontrol), named Rosellinia necatrix megabirnavirus 1 (RnMBV1), that possibly belongs to a new virus family.

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