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Parasites & Vectors Sep 2021Despite the medical importance of mosquitoes of the genus Anopheles in the transmission of malaria and other human diseases, its phylogenetic relationships are not...
BACKGROUND
Despite the medical importance of mosquitoes of the genus Anopheles in the transmission of malaria and other human diseases, its phylogenetic relationships are not settled, and the characteristics of mitochondrial genome (mitogenome) are not thoroughly understood.
METHODS
The present study sequenced and analyzed the complete mitogenomes of An. peditaeniatus and An. nitidus, investigated genome characteristics, and inferred the phylogenetic relationships of 76 Anopheles spp.
RESULTS
The complete mitogenomes of An. peditaeniatus and An. nitidus are 15,416 and 15,418 bp long, respectively, and both include 13 PCGs, 22 tRNAs, two tRNAs and one control region (CR). Mitogenomes of Anopheles spp. are similar to those of other insects in general characteristics; however, the trnR and trnA have been reversed to "trnR-trnA," as has been reported in other mosquito genera. Genome variations mainly occur in CR length (493-886 bp) with six repeat unit types identified for the first time that demonstrate an evolutionary signal. The subgenera Lophopodomyia, Stethomyia, Kerteszia, Nyssorhynchus, Anopheles and Cellia are inferred to be monophyletic, and the phylogenetic analyses support a new phylogenetic relationship among the six subgenera investigated, in that subgenus Lophopodomyia is the sister to all other five subgenera, and the remaining five subgenera are divided into two clades, one of which is a sister-taxon subgenera Stethomyia + Kerteszia, and the other consists of subgenus Nyssorhynchus as the sister to a sister-group subgenera Anopheles + Cellia. Four series (Neomyzomyia, Pyretophorus, Neocellia and Myzomyia) of the subgenus Cellia, and two series (Arribalzagia and Myzorhynchus) of the subgenus Anopheles were found to be monophyletic, whereas three sections (Myzorhynchella, Argyritarsis and Albimanus) and their subdivisions of the subgenus Nyssorhynchus were polyphyletic or paraphyletic.
CONCLUSIONS
The study comprehensively uncovered the characteristics of mitogenome and the phylogenetics based on mitogenomes in the genus Anopheles, and provided information for further study on the mitogenomes, phylogenetics and taxonomic revision of the genus.
Topics: Animals; Anopheles; Base Sequence; Evolution, Molecular; Genome, Mitochondrial; Phylogeny; Sequence Analysis, DNA; Species Specificity
PubMed: 34488869
DOI: 10.1186/s13071-021-04963-4 -
PloS One 2023Bacterial content of mosquitoes has given rise to the development of innovative tools that influence and seek to control malaria transmission. This study identified the...
Bacterial content of mosquitoes has given rise to the development of innovative tools that influence and seek to control malaria transmission. This study identified the bacterial microbiota in field-collected female adults of the Anopheles hyrcanus group and three Anopheles species, Anopheles nivipes, Anopheles philippinensis, and Anopheles vagus, from an endemic area in the southeastern part of Ubon Ratchathani Province, northeastern Thailand, near the Lao PDR-Cambodia-Thailand border. A total of 17 DNA libraries were generated from pooled female Anopheles abdomen samples (10 abdomens/ sample). The mosquito microbiota was characterized through the analysis of DNA sequences from the V3-V4 regions of the 16S rRNA gene, and data were analyzed in QIIME2. A total of 3,442 bacterial ASVs were obtained, revealing differences in the microbiota both within the same species/group and between different species/group. Statistical difference in alpha diversity was observed between An. hyrcanus group and An. vagus and between An. nivipes and An. vagus, and beta diversity analyses showed that the bacterial community of An. vagus was the most dissimilar from other species. The most abundant bacteria belonged to the Proteobacteria phylum (48%-75%) in which Pseudomonas, Serratia, and Pantoea were predominant genera among four Anopheles species/group. However, the most significantly abundant genus observed in each Anopheles species/group was as follows: Staphylococcus in the An. hyrcanus group, Pantoea in the An. nivipes, Rosenbergiella in An. philippinensis, and Pseudomonas in An. vagus. Particularly, Pseudomonas sp. was highly abundant in all Anopheles species except An. nivipes. The present study provides the first study on the microbiota of four potential malaria vectors as a starting step towards understanding the role of the microbiota on mosquito biology and ultimately the development of potential tools for malaria control.
Topics: Animals; Female; Anopheles; RNA, Ribosomal, 16S; Thailand; Mosquito Vectors; Malaria; Pantoea; Pseudomonas
PubMed: 37590198
DOI: 10.1371/journal.pone.0289733 -
Medical and Veterinary Entomology Sep 2020Species of the genus Anopheles vary with regard to their vector capacity for Plasmodium spp., the causative agent of malaria, and their accurate identification is often...
Species of the genus Anopheles vary with regard to their vector capacity for Plasmodium spp., the causative agent of malaria, and their accurate identification is often required. Loop-mediated isothermal amplification (LAMP) is a rapid, simple and low-cost method for specific DNA amplification. Primers for LAMP assays specific for the Anopheles funestus group and Anopheles gambiae complex species as well as for the species Anopheles arabiensis, An. funestus, An. gambiae s.s/Anopheles coluzzii (major vectors) and Anopheles rivulorum (minor vector) were designed targeting specific genome or rDNA internal transcribed spacer regions. Reaction conditions (buffer composition, primer concentrations, incubation time) were evaluated and the specificities of the assays confirmed with DNA from non-target Anopheles species. DNA release from the mosquitoes is achieved simply by heating them for 5 min in water. An aliquot of the DNA solutions is transferred to the reaction tube using disposable inoculation loops. The outcome of the LAMP amplifications after 1 h incubation at 65 °C can easily be visualized by a colour change visible to the naked eye. The assays are operable under field conditions requiring only basic equipment (portable heat block programmable at 65 and 80 °C, cooler for master mixes).
Topics: Animals; Anopheles; Molecular Diagnostic Techniques; Mosquito Vectors; Nucleic Acid Amplification Techniques
PubMed: 32154608
DOI: 10.1111/mve.12437 -
PLoS Neglected Tropical Diseases Jun 2022Mayaro virus (MAYV) is an arboviral pathogen in the genus Alphavirus that is circulating in South America with potential to spread to naïve regions. MAYV is also one of...
Mayaro virus (MAYV) is an arboviral pathogen in the genus Alphavirus that is circulating in South America with potential to spread to naïve regions. MAYV is also one of the few viruses with the ability to be transmitted by mosquitoes in the genus Anopheles, as well as the typical arboviral transmitting mosquitoes in the genus Aedes. Few studies have investigated the infection response of Anopheles mosquitoes. In this study we detail the transcriptomic and small RNA responses of An. stephensi to infection with MAYV via infectious bloodmeal at 2, 7, and 14 days post infection (dpi). 487 unique transcripts were significantly regulated, 78 putative novel miRNAs were identified, and an siRNA response is observed targeting the MAYV genome. Gene ontology analysis of transcripts regulated at each timepoint shows a number of proteases regulated at 2 and 7 dpi, potentially representative of Toll or melanization pathway activation, and repression of pathways related to autophagy and apoptosis at 14 dpi. These findings provide a basic understanding of the infection response of An. stephensi to MAYV and help to identify host factors which might be useful to target to inhibit viral replication in Anopheles mosquitoes.
Topics: Alphavirus; Alphavirus Infections; Animals; Anopheles; Arboviruses; MicroRNAs; Transcriptome
PubMed: 35763539
DOI: 10.1371/journal.pntd.0010507 -
Microbial Genomics Apr 2022is a genus of obligate bacterial endosymbionts that infect a diverse range of arthropod species as well as filarial nematodes, with its single described species, ,...
is a genus of obligate bacterial endosymbionts that infect a diverse range of arthropod species as well as filarial nematodes, with its single described species, , divided into several ‘supergroups’ based on multilocus sequence typing. strains in mosquitoes have been shown to inhibit the transmission of human pathogens, including malaria parasites and arboviruses. Despite their large host range, strains within the major malaria vectors of the and complexes appear at low density, established solely on PCR-based methods. Questions have been raised as to whether this represents a true endosymbiotic relationship. However, recent definitive evidence for two distinct, high-density strains of supergroup B within and has opened exciting possibilities to explore naturally occurring endosymbionts in for biocontrol strategies to block transmission. Here, we utilize genomic analyses to demonstrate that both strains have retained all key metabolic and transport pathways despite their smaller genome size, with this reduction potentially attributable to degenerated prophage regions. Even with this reduction, we confirmed the presence of cytoplasmic incompatibility (CI) factor genes within both strains, with AnD maintaining intact copies of these genes while the gene was interrupted in AnM, so functional analysis is required to determine whether AnM can induce CI. Additionally, phylogenetic analysis indicates that these strains may have been introduced into these two species via horizontal transmission events, rather than by ancestral acquisition and subsequent loss events in the species complex. These are the first genomes, to our knowledge, that enable us to study the relationship between natural strain malaria parasites and their anopheline hosts.
Topics: Animals; Anopheles; Prophages; Symbiosis; Wolbachia
PubMed: 35446252
DOI: 10.1099/mgen.0.000805 -
Scientific Reports Jan 2022Using high-depth whole genome sequencing of F0 mating pairs and multiple individual F1 offspring, we estimated the nuclear mutation rate per generation in the malaria...
Using high-depth whole genome sequencing of F0 mating pairs and multiple individual F1 offspring, we estimated the nuclear mutation rate per generation in the malaria vectors Anopheles coluzzii and Anopheles stephensi by detecting de novo genetic mutations. A purpose-built computer program was employed to filter actual mutations from a deep background of superficially similar artifacts resulting from read misalignment. Performance of filtering parameters was determined using software-simulated mutations, and the resulting estimate of false negative rate was used to correct final mutation rate estimates. Spontaneous mutation rates by base substitution were estimated at 1.00 × 10 (95% confidence interval, 2.06 × 10-2.91 × 10) and 1.36 × 10 (95% confidence interval, 4.42 × 10-3.18 × 10) per site per generation in A. coluzzii and A. stephensi respectively. Although similar studies have been performed on other insect species including dipterans, this is the first study to empirically measure mutation rates in the important genus Anopheles, and thus provides an estimate of µ that will be of utility for comparative evolutionary genomics, as well as for population genetic analysis of malaria vector mosquito species.
Topics: Animals; Anopheles; Female; Humans; Insect Proteins; Malaria; Male; Mosquito Vectors; Mutation Rate; Whole Genome Sequencing
PubMed: 34996998
DOI: 10.1038/s41598-021-03943-z -
PLoS Neglected Tropical Diseases Jun 2023West Nile virus (WNV) and Usutu virus (USUV) are two arthropod-borne viruses that circulate in mainland France. Assessing vector competence has only been conducted so...
West Nile virus (WNV) and Usutu virus (USUV) are two arthropod-borne viruses that circulate in mainland France. Assessing vector competence has only been conducted so far with mosquitoes from southern France while an increasingly active circulation of WNV and USUV has been reported in the last years. The main vectors are mosquitoes of the Culex genus and the common mosquito Culex pipiens. Here, we measure the vector competence of five mosquito species (Aedes rusticus, Aedes albopictus, Anopheles plumbeus, Culex pipiens and Culiseta longiareolata) present in northeastern France. Field-collected populations were exposed to artificial infectious blood meal containing WNV or USUV and examined at different days post-infection. We show that (i) Cx. pipiens transmitted WNV and USUV, (ii) Ae. rusticus only WNV, and (iii) unexpectedly, Ae. albopictus transmitted both WNV and USUV. Less surprising, An. plumbeus was not competent for both viruses. Combined with data on distribution and population dynamics, these assessments of vector competence will help in developing a risk map and implementing appropriate prevention and control measures.
Topics: Animals; West Nile virus; Flavivirus; Culex; Aedes; France; Mosquito Vectors; West Nile Fever
PubMed: 37276229
DOI: 10.1371/journal.pntd.0011144 -
Scientific Reports Aug 2023We present a new and innovative identification method based on deep learning of the wing interferential patterns carried by mosquitoes of the Anopheles genus to classify...
We present a new and innovative identification method based on deep learning of the wing interferential patterns carried by mosquitoes of the Anopheles genus to classify and assign 20 Anopheles species, including 13 malaria vectors. We provide additional evidence that this approach can identify Anopheles spp. with an accuracy of up to 100% for ten out of 20 species. Although, this accuracy was moderate (> 65%) or weak (50%) for three and seven species. The accuracy of the process to discriminate cryptic or sibling species is also assessed on three species belonging to the Gambiae complex. Strikingly, An. gambiae, An. arabiensis and An. coluzzii, morphologically indistinguishable species belonging to the Gambiae complex, were distinguished with 100%, 100%, and 88% accuracy respectively. Therefore, this tool would help entomological surveys of malaria vectors and vector control implementation. In the future, we anticipate our method can be applied to other arthropod vector-borne diseases.
Topics: Animals; Humans; Anopheles; Deep Learning; Mosquito Vectors; Arthropods; Siblings
PubMed: 37626130
DOI: 10.1038/s41598-023-41114-4 -
Viruses Aug 2023The diversity and circulation of arboviruses are not much studied in Madagascar. The fact is that arboviral emergences are rarely detected. The existing surveillance...
The diversity and circulation of arboviruses are not much studied in Madagascar. The fact is that arboviral emergences are rarely detected. The existing surveillance system primarily relies on serological detection and records only a few human infections annually. The city of Mahajanga, however, experienced a confirmed dengue fever epidemic in 2020 and 2021. This study aimed to characterize and analyze the virome of mosquitoes collected in Mahajanga, near patients with dengue-like syndromes to detect known and unknown viruses as well as investigate the factors contributing to the relative low circulation of arboviruses in the area. A total of 4280 mosquitoes representing at least 12 species from the , , and genera were collected during the dry and the rainy seasons from three sites, following an urbanization gradient. The virome analysis of 2192 female mosquitoes identified a diverse range of viral families and genera and revealed different patterns that are signatures of the influence of the mosquito genus or the season of collection on the composition and abundance of the virome. Despite the absence of known human or veterinary arboviruses, the identification and characterization of viral families, genera, and species in the mosquito virome contribute to our understanding of viral ecology and diversity within mosquito populations in Madagascar. This study serves as a foundation for ongoing surveillance efforts and provides a basis for the development of preventive strategies against various mosquito-borne viral diseases, including known arboviruses.
PubMed: 37766259
DOI: 10.3390/v15091852 -
Frontiers in Genetics 2020Malaria remains a major healthcare risk to growing economies like India, and a chromosome-level reference genome of is critical for successful vector management and...
Malaria remains a major healthcare risk to growing economies like India, and a chromosome-level reference genome of is critical for successful vector management and understanding of vector evolution using comparative genomics. We report chromosome-level assemblies of an Indian strain, STE2, and a Pakistani strain SDA-500 by combining draft genomes of the two strains using a homology-based iterative approach. The resulting assembly IndV3/PakV3 with L50 of 9/12 and N50 6.3/6.9 Mb had scaffolds long enough for building 90% of the euchromatic regions of the three chromosomes, IndV3s/PakV3s, using low-resolution physical markers and enabled the generation of the next version of genome assemblies, IndV4/PakV4, using HiC data. We have validated these assemblies using contact maps against publicly available HiC raw data from two strains including STE2 and another lab strain of from UCI and compare the quality of the assemblies with other assemblies made available as preprints since the submission of the manuscript. We show that the IndV3s and IndV4 assemblies are sensitive in identifying a homozygous 2Rb inversion in the UCI strain and a 2Rb polymorphism in the STE2 strain. Multiple tandem copies of CYP6a14, 4c1, and 4c21 genes, implicated in insecticide resistance, lie within this inversion locus. Comparison of assembled genomes suggests a variation of 1 in 81 positions between the UCI and STE2 lab strains, 1 in 82 between SDA-500 and UCI strain, and 1 in 113 between SDA-500 and STE2 strains of , which are closer than 1 in 68 variations among individuals from two other lab strains sequenced and reported here. Based on the developmental transcriptome and orthology of all the 54 olfactory receptors (ORs) to those of other species, we identify an OR with the potential for host recognition in the genus . A comparative analysis of genomes with the completed genomes of a few other species suggests limited inter-chromosomal gene flow and loss of synteny within chromosomal arms even among the closely related species.
PubMed: 33312190
DOI: 10.3389/fgene.2020.565626