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result(s) for
"Troco, Arlete D."
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The V410L knockdown resistance mutation occurs in island and continental populations of Aedes aegypti in West and Central Africa
by
Monteiro, Inilça
,
Troco, Arlete D.
,
Pinto, João
in
Aedes - drug effects
,
Aedes - genetics
,
Aedes - metabolism
2020
The extensive use of insecticides for vector control has led to the development of insecticide resistance in Aedes aegypti populations on a global scale, which has significantly compromised control actions. Insecticide resistance, and its underlying mechanisms, has been investigated in several countries, mostly in South American and Asian countries. In Africa, however, studies reporting insecticide resistance are rare and data on resistance mechanisms, notably knockdown resistance (kdr) mutations, is scarce. In this study, the recently described V410L kdr mutation is reported for the first time in old world Ae. aegypti populations, namely from Angola and Madeira island. Two additional kdr mutations, V1016I and F1534C, are also reported for the first time in populations from Angola and Cape Verde. Significant associations with the resistance phenotype were found for both V410L and V1016I individually as well as for tri-locus genotypes in the Angolan population. However, no association was found in Madeira island, probably due to the presence of a complex pattern of multiple insecticide resistance mechanisms in the local Ae. aegypti population. These results suggest that populations carrying the same kdr mutations may respond differently to the same insecticide, stressing the need for complementary studies when assessing the impact of kdr resistance mechanisms in the outcome of insecticide-based control strategies.
Journal Article
Population structure of a vector of human diseases: Aedes aegypti in its ancestral range, Africa
2018
Aedes aegypti, the major vector of dengue, yellow fever, chikungunya, and Zika viruses, remains of great medical and public health concern. There is little doubt that the ancestral home of the species is Africa. This mosquito invaded the New World 400‐500 years ago and later, Asia. However, little is known about the genetic structure and history of Ae. aegypti across Africa, as well as the possible origin(s) of the New World invasion. Here, we use ~17,000 genome‐wide single nucleotide polymorphisms (SNPs) to characterize a heretofore undocumented complex picture of this mosquito across its ancestral range in Africa. We find signatures of human‐assisted migrations, connectivity across long distances in sylvan populations, and of local admixture between domestic and sylvan populations. Finally, through a phylogenetic analysis combined with the genetic structure analyses, we suggest West Africa and especially Angola as the source of the New World's invasion, a scenario that fits well with the historic record of 16th‐century slave trade between Africa and Americas. We have detected distinct genetic structuring of populations of the major vector of human diseases Aedes aegypti in its native range, Africa. Both isolation by distance and long‐range anthropogenic migration are observed. Strong evidence indicates Angola populations gave rise to the species outside Africa.
Journal Article
Genetic diversity of the African malaria vector Anopheles gambiae
2017
Genome sequencing analyses from 765 specimens of
Anopheles gambiae
and
Anopheles coluzzii
from 15 locations across Africa characterize patterns of gene flow and variations in population size, and provide a resource for studying the evolution of natural malaria vector populations.
Mosquito genetic diversity dataset
Anopheles gambiae
is the primary mosquito vector responsible for the transmission of malaria in most of sub-Saharan Africa. Alistair Miles, Dominic Kwiatkowski and colleagues report analyses from the
Anopheles gambiae
1000 Genomes Project (Ag1000G), including low-coverage genome sequences of 765 specimens of
Anopheles gambiae
and
Anopheles coluzzii
, caught in the wild at 15 locations across 8 countries in Africa. The authors analyse genetic variation, finding a high level of genetic diversity in these populations, and characterize patterns of gene flow and variations in population size. These datasets provide a resource for studies into the evolution of malaria vector populations that could guide control strategies and be used to address problems such as the evolution of insecticide resistance.
The sustainability of malaria control in Africa is threatened by the rise of insecticide resistance in
Anopheles
mosquitoes, which transmit the disease
1
. To gain a deeper understanding of how mosquito populations are evolving, here we sequenced the genomes of 765 specimens of
Anopheles gambiae
and
Anopheles coluzzii
sampled from 15 locations across Africa, and identified over 50 million single nucleotide polymorphisms within the accessible genome. These data revealed complex population structure and patterns of gene flow, with evidence of ancient expansions, recent bottlenecks, and local variation in effective population size. Strong signals of recent selection were observed in insecticide-resistance genes, with several sweeps spreading over large geographical distances and between species. The design of new tools for mosquito control using gene-drive systems will need to take account of high levels of genetic diversity in natural mosquito populations.
Journal Article
Resistance to pirimiphos-methyl in West African Anopheles is spreading via duplication and introgression of the Ace1 locus
by
Kwiatkowski, Dominic
,
Essandoh, John
,
Lucas, Eric
in
Acetylcholinesterase - genetics
,
Africa, Western
,
Animals
2021
Vector population control using insecticides is a key element of current strategies to prevent malaria transmission in Africa. The introduction of effective insecticides, such as the organophosphate pirimiphos-methyl, is essential to overcome the recurrent emergence of resistance driven by the highly diverse Anopheles genomes. Here, we use a population genomic approach to investigate the basis of pirimiphos-methyl resistance in the major malaria vectors Anopheles gambiae and A . coluzzii . A combination of copy number variation and a single non-synonymous substitution in the acetylcholinesterase gene, Ace1 , provides the key resistance diagnostic in an A . coluzzii population from Côte d’Ivoire that we used for sequence-based association mapping, with replication in other West African populations. The Ace1 substitution and duplications occur on a unique resistance haplotype that evolved in A . gambiae and introgressed into A . coluzzii , and is now common in West Africa primarily due to selection imposed by other organophosphate or carbamate insecticides. Our findings highlight the predictive value of this complex resistance haplotype for phenotypic resistance and clarify its evolutionary history, providing tools to for molecular surveillance of the current and future effectiveness of pirimiphos-methyl based interventions.
Journal Article
Genome variation and population structure among 1,142 mosquitoes of the African malaria vector species Anopheles gambiae and Anopheles coluzzii
by
Mbogo, Charles
,
Jeffreys, Anna E
,
Essandoh, John
in
Anopheles coluzzii
,
Anopheles gambiae
,
Copy number
2020
Mosquito control remains a central pillar of efforts to reduce malaria burden in sub-Saharan Africa. However, insecticide resistance is entrenched in malaria vector populations, and countries with high malaria burden face a daunting challenge to sustain malaria control with a limited set of surveillance and intervention tools. Here we report on the second phase of a project to build an open resource of high quality data on genome variation among natural populations of the major African malaria vector species Anopheles gambiae and Anopheles coluzzii. We analysed whole genomes of 1,142 individual mosquitoes sampled from the wild in 13 African countries, and a further 234 individuals comprising parents and progeny of 11 lab crosses. The data resource includes high confidence single nucleotide polymorphism (SNP) calls at 57 million variable sites, genome-wide copy number variation (CNV) calls, and haplotypes phased at biallelic SNPs. We used these data to analyse genetic population structure and characterise genetic diversity within and between populations. We illustrate the utility of these data by investigating species differences in isolation by distance, genetic variation within proposed gene drive target sequences, and patterns of resistance to pyrethroid insecticides. This data resource provides a foundation for developing new operational systems for molecular surveillance, and for accelerating research and development of new vector control tools. Footnotes * Figure 2 has been updated to replace a PCA analysis with a UMAP analysis, and the PCA analysis has been moved to a supplementary figure. Minor corrections and improvements to figures and text. * https://www.malariagen.net/resource/27