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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 -
Toxins Jun 2023Malaria is an infectious disease caused by spp. and it is mainly transmitted to humans by female mosquitoes of the genus . Malaria is an important global public health... (Review)
Review
Malaria is an infectious disease caused by spp. and it is mainly transmitted to humans by female mosquitoes of the genus . Malaria is an important global public health problem due to its high rates of morbidity and mortality. At present, drug therapies and vector control with insecticides are respectively the most commonly used methods for the treatment and control of malaria. However, several studies have shown the resistance of to drugs that are recommended for the treatment of malaria. In view of this, it is necessary to carry out studies to discover new antimalarial molecules as lead compounds for the development of new medicines. In this sense, in the last few decades, animal venoms have attracted attention as a potential source for new antimalarial molecules. Therefore, the aim of this review was to summarize animal venom toxins with antimalarial activity found in the literature. From this research, 50 isolated substances, 4 venom fractions and 7 venom extracts from animals such as anurans, spiders, scorpions, snakes, and bees were identified. These toxins act as inhibitors at different key points in the biological cycle of and may be important in the context of the resistance of to currently available antimalarial drugs.
Topics: Female; Humans; Animals; Antimalarials; Venoms; Mosquito Vectors; Plasmodium; Malaria; Toxins, Biological; Anopheles; Plasmodium falciparum
PubMed: 37368676
DOI: 10.3390/toxins15060375 -
Mitochondrial DNA. Part B, Resources 2022We present the complete mitochondrial genome of a Malaria vector Mosquito Wiedemann, 1828 from South Korea. The mitochondrial genome is about 15,421 bp long and...
We present the complete mitochondrial genome of a Malaria vector Mosquito Wiedemann, 1828 from South Korea. The mitochondrial genome is about 15,421 bp long and contains 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and an A-T rich region. The present data were compared with those from China with respect to PCG sequence differences, tRNA structure, gene order, and control region (CR) structure. mitochondrial genomes from northeast Asia share identical gene composition and gene order. In contrast, they have distinct differences in the CR within the range 8.75% (51/583 bp) to 9.95% (58/583 bp). The phylogenetic analysis showed that from South Korea was clustered together with those from China, but there existed distinct genetic distance between the two. Likewise, mitochondrial genome sequences from other species were employed to infer phylogenetic relationships among the members of the genus . This study further promotes the enrichment of mitochondrial genome data, providing useful information for their mitochondrial genetic differences along with geographical distances in northeast Asia.
PubMed: 35692711
DOI: 10.1080/23802359.2022.2077665 -
Travel Medicine and Infectious Disease 2013Travellers are confronted with a variety of vector-borne threats. Is one type of repellent effective against all biting vectors? The aim of this review is to examine the... (Review)
Review
BACKGROUND
Travellers are confronted with a variety of vector-borne threats. Is one type of repellent effective against all biting vectors? The aim of this review is to examine the literature, up to December 31st, 2012, regarding repellent efficacy.
METHODS
We searched PubMed for relevant papers. Repellents of interest were DEET, Icaridin as well as other piperidine-derived products (SS220), Insect Repellent (IR) 3535 (ethyl-butylacetyl-amino-propionat, EBAAP) and plant-derived products, including Citriodora (para-menthane-3,8-diol). As vectors, we considered the mosquito species Anopheles, Aedes and Culex as well as the tick species Ixodes. We selected only studies evaluating the protective efficacy of repellents on human skin.
RESULTS
We reviewed a total of 102 publications. Repellents were evaluated regarding complete protection time or as percentage efficacy [%] in a time interval. We found no standardized study for tick bite prevention.
CONCLUSIONS
Regarding Aedes, DEET at concentration of 20% or more, showed the best efficacy providing up to 10 h protection. Citriodora repellency against this mosquito genus was lower compared to the other products. Also between subspecies a difference could be observed: Ae. aegypti proved more difficult to repel than Ae. Albopictus. Fewer studies have been conducted on mosquito species Anopheles and Culex. The repellency profile against Anopheles species was similar for the four principal repellents of interest, providing on average 4-10 h of protection. Culex mosquitoes are easier to repel and all four repellents provided good protection. Few studies have been conducted on the tick species Ixodes. According to our results, the longest protection against Ixodes scapularis was provided by repellents containing IR3535, while DEET and commercial products containing Icaridin or PMD showed a better response than IR3535 against Ixodes ricinus. Many plant-based repellents provide only short duration protection. Adding vanillin 5% to plant-based repellents and to DEET repellents increased the protection by about 2 h.
Topics: Animals; Culicidae; Insect Repellents; Ixodes
PubMed: 24201040
DOI: 10.1016/j.tmaid.2013.10.005 -
Malaria Journal Jun 2021Genus Anopheles mosquitoes are the primary vectors of human malaria, which is a serious threat to public health worldwide. To reduce the spread of malaria and identify...
BACKGROUND
Genus Anopheles mosquitoes are the primary vectors of human malaria, which is a serious threat to public health worldwide. To reduce the spread of malaria and identify the malaria infection rates in mosquitoes, accurate species identification is needed. Malaria re-emerged in 1993 in the Republic of Korea (ROK), with numbers peaking in 2004 before decreasing to current levels. Eight Anopheles species (Anopheles sinensis, Anopheles pullus, Anopheles belenrae, Anopheles lesteri, Anopheles kleini, Anopheles sineroides, Anopheles koreicus, Anopheles lindesayi) are distributed throughout Korea. Members of the Anopheles Hyrcanus group currently cannot be identified morphologically. The other species of Anopheles can be identified morphologically, except when specimens are damaged in traps. The purpose of this study was to develop a rapid and accurate method for simultaneous molecular identification of the eight Anopheles species present in the ROK.
METHODS
Anopheles spp. used in this study were collected near/in the demilitarized zone in ROK, where most malaria cases are reported. DNA from 165 of the Anopheles specimens was used to develop a multiplex PCR assay. The internal transcribed spacer 2 (ITS2) region of each species was sequenced and analysed for molecular identification.
RESULTS
DNA from a total of 165 Anopheles specimens was identified to species using a multiplex diagnostic system. These included: 20 An. sinensis, 21 An. koreicus, 17 An. lindesayi, 25 An. kleini, 11 An. lesteri, 22 An. sineroides, 23 An. belenrae, and 26 An. pullus. Each species was clearly distinguished by electrophoresis as follows: 1,112 bp for An. sinensis; 925 bp for An. koreicus; 650 bp for An. lindesayi; 527 bp for An. kleini; 436 bp for An. lesteri; 315 bp for An. sineroides; 260 bp for An. belenrae; and, 157 bp for An. pullus.
CONCLUSION
A multiplex PCR assay was developed to identify Anopheles spp. distributed in ROK. This method can be used to accurately identify Anopheles species that are difficult to identify morphologically to determine species distributions and malaria infection rates.
Topics: Animals; Anopheles; Mosquito Vectors; Multiplex Polymerase Chain Reaction; Republic of Korea
PubMed: 34183006
DOI: 10.1186/s12936-021-03808-w -
Verhandelingen - Koninklijke Academie... 2011Malaria is a global tropical disease causing more than 1 million deaths and 300 million clinical cases every year. It is caused by parasites from the genus Plasmodium... (Review)
Review
Malaria is a global tropical disease causing more than 1 million deaths and 300 million clinical cases every year. It is caused by parasites from the genus Plasmodium and is transmitted by Anopheles mosquitoes. Approximately 3 billion people live in malaria-endemic regions and a majority of them are infected. In this review, we discuss the life cycle of the parasite, the complex interactions with the human host and the ensuing immune reactions and complications. The immune system plays a dual role in malaria, by providing life-saving immunity against the parasite, but also by causing often lethal complications in a number of patients. Cytokines, chemokines and proteases are key players in the immunopathological complications, and we propose immunomodulation with dexamethasone as a promising strategy for the therapy of malaria-associated acute respiratory distress syndrome.
Topics: Animals; Anopheles; Antimalarials; Host-Parasite Interactions; Humans; Insect Vectors; Malaria; Plasmodium
PubMed: 22276399
DOI: No ID Found -
PloS One 2020Malaria is a life-threatening disease, caused by Apicomplexan parasites of the Plasmodium genus. The Anopheles mosquito is necessary for the sexual replication of these...
Malaria is a life-threatening disease, caused by Apicomplexan parasites of the Plasmodium genus. The Anopheles mosquito is necessary for the sexual replication of these parasites and for their transmission to vertebrate hosts, including humans. Imaging of the parasite within the insect vector has been attempted using multiple microscopy methods, most of which are hampered by the presence of the light scattering opaque cuticle of the mosquito. So far, most imaging of the Plasmodium mosquito stages depended on either sectioning or surgical dissection of important anatomical sites, such as the midgut and the salivary glands. Optical projection tomography (OPT) and light sheet fluorescence microscopy (LSFM) enable imaging fields of view in the centimeter scale whilst providing micrometer resolution. In this paper, we compare different optical clearing protocols and present reconstructions of the whole body of Plasmodium-infected, optically cleared Anopheles stephensi mosquitoes and their midguts. The 3D-reconstructions from OPT imaging show detailed features of the mosquito anatomy and enable overall localization of parasites in midguts. Additionally, LSFM imaging of mosquito midguts shows detailed distribution of oocysts in extracted midguts. This work was submitted as a pre-print to bioRxiv, available at https://www.biorxiv.org/content/10.1101/682054v2.
Topics: Animals; Anopheles; Imaging, Three-Dimensional; Insect Vectors; Microscopy, Fluorescence; Plasmodium; Tomography, Optical
PubMed: 32936796
DOI: 10.1371/journal.pone.0238134 -
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 -
Parasites & Vectors Nov 2020The worldwide genus Anopheles Meigen, 1918 is the only genus containing species evolved as vectors of human and simian malaria. Morbidity and mortality caused by...
BACKGROUND
The worldwide genus Anopheles Meigen, 1918 is the only genus containing species evolved as vectors of human and simian malaria. Morbidity and mortality caused by Plasmodium Marchiafava & Celli, 1885 is tremendous, which has made these parasites and their vectors the objects of intense research aimed at mosquito identification, malaria control and elimination. DNA tools make the identification of Anopheles species both easier and more difficult. Easier in that putative species can nearly always be separated based on DNA data; more difficult in that attaching a scientific name to a species is often problematic because morphological characters are often difficult to interpret or even see; and DNA technology might not be available and affordable. Added to this are the many species that are either not yet recognized or are similar to, or identical with, named species. The first step in solving Anopheles identification problem is to attach a morphology-based formal or informal name to a specimen. These names are hypotheses to be tested with further morphological observations and/or DNA evidence. The overarching objective is to be able to communicate about a given species under study. In South America, morphological identification which is the first step in the above process is often difficult because of lack of taxonomic expertise and/or inadequate identification keys, written for local fauna, containing the most consequential species, or obviously, do not include species described subsequent to key publication.
METHODS
Holotypes and paratypes and other specimens deposited in the Coleção Entomológica de Referência, Faculdade de Saúde Pública (FSP-USP), Museo de Entomología, Universidad del Valle (MUSENUV) and the US National Mosquito Collection, Smithsonian Institution (USNMC) were examined and employed to illustrate the identification keys for female, male and fourth-instar larvae of Anopheles.
RESULTS
We presented, in four concurrent parts, introduction and three keys to aid the identification of South American Anopheles based on the morphology of the larvae, male genitalia and adult females, with the former two keys fully illustrated.
CONCLUSIONS
Taxonomic information and identification keys for species of the genus Anopheles are updated. The need for further morphology-based studies and description of new species are reinforced.
Topics: Animals; Anopheles; Female; Genitalia; Larva; Malaria; Male; Mosquito Vectors; South America
PubMed: 33208196
DOI: 10.1186/s13071-020-04298-6 -
BMC Genomics Apr 2015Long non-coding RNAs (lncRNAs) have been defined as mRNA-like transcripts longer than 200 nucleotides that lack significant protein-coding potential, and many of them...
BACKGROUND
Long non-coding RNAs (lncRNAs) have been defined as mRNA-like transcripts longer than 200 nucleotides that lack significant protein-coding potential, and many of them constitute scaffolds for ribonucleoprotein complexes with critical roles in epigenetic regulation. Various lncRNAs have been implicated in the modulation of chromatin structure, transcriptional and post-transcriptional gene regulation, and regulation of genomic stability in mammals, Caenorhabditis elegans, and Drosophila melanogaster. The purpose of this study is to identify the lncRNA landscape in the malaria vector An. gambiae and assess the evolutionary conservation of lncRNAs and their secondary structures across the Anopheles genus.
RESULTS
Using deep RNA sequencing of multiple Anopheles gambiae life stages, we have identified 2,949 lncRNAs and more than 300 previously unannotated putative protein-coding genes. The lncRNAs exhibit differential expression profiles across life stages and adult genders. We find that across the genus Anopheles, lncRNAs display much lower sequence conservation than protein-coding genes. Additionally, we find that lncRNA secondary structure is highly conserved within the Gambiae complex, but diverges rapidly across the rest of the genus Anopheles.
CONCLUSIONS
This study offers one of the first lncRNA secondary structure analyses in vector insects. Our description of lncRNAs in An. gambiae offers the most comprehensive genome-wide insights to date into lncRNAs in this vector mosquito, and defines a set of potential targets for the development of vector-based interventions that may further curb the human malaria burden in disease-endemic countries.
Topics: Animals; Anopheles; Conserved Sequence; Drosophila melanogaster; Epigenesis, Genetic; Gene Expression Regulation; Humans; Nucleic Acid Conformation; RNA, Long Noncoding; RNA, Messenger
PubMed: 25903279
DOI: 10.1186/s12864-015-1507-3