Ecology and genetics of insecticide resistance inHelicoverpa armigera: Interactions between selection and gene flow

Genetica ◽  
1993 ◽  
Vol 90 (2-3) ◽  
pp. 217-226 ◽  
Author(s):  
J. C. Daly
Keyword(s):  
Gene Flow ◽  
Insecticide Resistance

scholarly journals A differential expression of pyrethroid resistance genes in the malaria vector Anopheles funestus across Uganda is associated with patterns of gene flow

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0240743
Author(s):  
Maurice Marcel Sandeu ◽  
Charles Mulamba ◽  
Gareth D. Weedall ◽  
Charles S. Wondji
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Insecticide Resistance ◽  
Pyrethroid Resistance ◽  
Anopheles Funestus ◽  
Metabolic Resistance ◽  
Transcription Analysis ◽  
Genome Wide

Background Insecticide resistance is challenging the effectiveness of insecticide-based control interventions to reduce malaria burden in Africa. Understanding the molecular basis of insecticides resistance and patterns of gene flow in major malaria vectors such as Anopheles funestus are important steps for designing effective resistance management strategies. Here, we investigated the association between patterns of genetic structure and expression profiles of genes involved in the pyrethroid resistance in An. funestus across Uganda and neighboring Kenya. Methods Blood-fed mosquitoes An. funestus were collected across the four localities in Uganda and neighboring Kenya. A Microarray-based genome-wide transcription analysis was performed to identify the set of genes associated with permethrin resistance. 17 microsatellites markers were genotyped and used to establish patterns of genetic differentiation. Results Microarray-based genome-wide transcription profiling of pyrethroid resistance in four locations across Uganda (Arua, Bulambuli, Lira, and Tororo) and Kenya (Kisumu) revealed that resistance was mainly driven by metabolic resistance. The most commonly up-regulated genes in pyrethroid resistance mosquitoes include cytochrome P450s (CYP9K1, CYP6M7, CYP4H18, CYP4H17, CYP4C36). However, expression levels of key genes vary geographically such as the P450 CYP6M7 [Fold-change (FC) = 115.8 (Arua) vs 24.05 (Tororo) and 16.9 (Kisumu)]. In addition, several genes from other families were also over-expressed including Glutathione S-transferases (GSTs), carboxylesterases, trypsin, glycogenin, and nucleotide binding protein which probably contribute to insecticide resistance across Uganda and Kenya. Genotyping of 17 microsatellite loci in the five locations provided evidence that a geographical shift in the resistance mechanisms could be associated with patterns of population structure throughout East Africa. Genetic and population structure analyses indicated significant genetic differentiation between Arua and other localities (FST>0.03) and revealed a barrier to gene flow between Arua and other areas, possibly associated with Rift Valley. Conclusion The correlation between patterns of genetic structure and variation in gene expression could be used to inform future interventions especially as new insecticides are gradually introduced.

scholarly journals Insecticide resistance and genetic structure of Aedes aegypti populations from Rio de Janeiro State, Brazil

2021 ◽  
Vol 15 (2) ◽  
pp. e0008492 ◽  
Author(s):  
Rafi Ur Rahman ◽  
Luciano Veiga Cosme ◽  
Monique Melo Costa ◽  
Luana Carrara ◽  
José Bento Pereira Lima ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Aedes Aegypti ◽  
Insecticide Resistance ◽  
Vector Control ◽  
Rio De Janeiro ◽  
Control Program ◽  
Positive Control ◽  
World Health ◽  
Janeiro State

Vector control largely relies on neurotoxic chemicals, and insecticide resistance (IR) directly threatens their effectiveness. In some cases, specific alleles cause IR, and knowledge of the genetic diversity and gene flow among mosquito populations is crucial to track their arrival, rise, and spread. Here we evaluated Aedes aegypti populations’ susceptibility status, collected in 2016 from six different municipalities of Rio de Janeiro state (RJ), to temephos, pyriproxyfen, malathion, and deltamethrin. We collected eggs of Ae. aegypti in Campos dos Goytacazes (Cgy), Itaperuna (Ipn), Iguaba Grande (Igg), Itaboraí (Ibr), Mangaratiba (Mgr), and Vassouras (Vsr). We followed the World Health Organization (WHO) guidelines and investigated the degree of susceptibility/resistance of mosquitoes to these insecticides. We used the Rockefeller strain as a susceptible positive control. We genotyped the V1016I and F1534C knockdown resistance (kdr) alleles using qPCR TaqMan SNP genotyping assay. Besides, with the use of Ae. aegypti SNP-chip, we performed genomic population analyses by genotyping more than 15,000 biallelic SNPs in mosquitoes from each population. We added previous data from populations from other countries to evaluate the ancestry of RJ populations. All RJ Ae. aegypti populations were susceptible to pyriproxyfen and malathion and highly resistant to deltamethrin. The resistance ratios for temephos was below 3,0 in Cgy, Ibr, and Igg populations, representing the lowest rates since IR monitoring started in this Brazilian region. We found the kdr alleles in high frequencies in all populations, partially justifying the observed resistance to pyrethroid. Population genetics analysis showed that Ae. aegypti revealed potential higher migration among some RJ localities and low genetic structure for most of them. Future population genetic studies, together with IR data in Ae aegypti on a broader scale, can help us predict the gene flow within and among the Brazilian States, allowing us to track the dynamics of arrival and changes in the frequency of IR alleles, and providing critical information to improving vector control program.

scholarly journals Evaluating Gene Flow Using Selected Markers: A Case Study

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1383-1392 ◽  
Author(s):  
Thomas Lenormand ◽  
Thomas Guillemaud ◽  
Denis Bourguet ◽  
Michel Raymond
Keyword(s):  
Gene Flow ◽  
Insecticide Resistance ◽  
Local Adaptation ◽  
Culex Pipiens ◽  
Selection Pressure ◽  
Fitness Costs ◽  
Southern France ◽  
Culex Pipiens Pipiens ◽  
Selection Intensities

Abstract The extent to which an organism is locally adapted in an environmental pocket depends on the selection intensities inside and outside the pocket, on migration, and on the size of the pocket. When two or more loci are involved in this local adaptation, measuring their frequency gradients and their linkage disequilbria allows one to disentangle the forces—migration and selection—acting on the system. We apply this method to the case of a local adaptation to organophosphate insecticides in the mosquito Culex pipiens pipiens in southern France. The study of two different resistance loci allowed us to estimate with support limits gene flow as well as selection pressure on insecticide resistance and the fitness costs associated with each locus. These estimates permit us to pinpoint the conditions for the maintenance of this pocket of adaptation as well as the effect of the interaction between the two resistance loci.

scholarly journals Liaisons dangereuses: cross-border gene flow and dispersal of insecticide resistance-associated genes in the mosquito Aedes aegypti from Brazil and French Guiana

2019 ◽  
Vol 114 ◽  
Author(s):  
Patrícia Salgueiro ◽  
Johana Restrepo-Zabaleta ◽  
Monique Costa ◽  
Allan Kardec Ribeiro Galardo ◽  
João Pinto ◽  
...  
Keyword(s):  
Gene Flow ◽  
Aedes Aegypti ◽  
Insecticide Resistance ◽  
French Guiana ◽  
Cross Border

scholarly journals “Genetic structure and sodium channel gene mutation analysis related to pyrethroid insecticide toxicity in sylvatic Andean Triatoma infestans from Bolivia”

2019 ◽  
Author(s):  
Paula L. Marcet ◽  
Pablo Santo-Orihuela ◽  
Louisa A. Messenger ◽  
Claudia V. Vassena
Keyword(s):  
Gene Flow ◽  
Insecticide Resistance ◽  
Sodium Channel ◽  
Vector Control ◽  
Population Distribution ◽  
Pyrethroid Resistance ◽  
Triatoma Infestans ◽  
Insecticide Susceptibility ◽  
Channel Gene ◽  
Sodium Channel Gene

ABSTRACTBACKGROUNDSylvatic populations of Triatoma infestans represent a challenge for vector control as these populations are not targeted by control activities and could play a key role in post-spraying house re-infestation. Improved understanding of sylvatic foci, population distribution, dispersion patterns, gene flow between sylvatic and domestic populations, as well as characterization of insecticide resistance profiles, is crucial to optimize vector control interventions.METHODSWe analyzed the genetic relationship of five Andean populations from Bolivia from localities with distinct insecticide susceptibility profiles (sylvatic: 20 de Octubre, Illicuni, Kirus Mayu and Mataral and one domestic from Mataral). Individual multilocus genotypes based on 8 microsatellites and the DNA sequence of a fragment of the cytochrome B (cytB) gene were obtained for 92 individuals. We compared the cytB haplotypes with previously reported Andean T. infestans haplotypes and evaluated the directionality and possibly history of gene flow among populations. Each specimen was screened for 2 nucleotide mutations (L1014 and L9251) of the sodium channel gene (kdr), described for T. infestans and related to pyrethroid resistance.RESULTSSignificant genetic differentiation was observed among all populations, reflecting current genetic isolation among them. However, individuals of admixed origin were detected in four populations, especially between the sylvatic and domestic populations from Mataral. Historical analysis of gene flow suggests that insecticide resistance is conferred by ancient trait(s) in T. infestans sylvatic populations that are capable of invading domiciles. The kdr mutation L1014 was identified in one individual from Mataral, while the L9251 mutation was not detected in any population. The low frequency of kdr mutations in these populations suggests this mechanism is unlikely to be the primary cause of the observed altered insecticide susceptibility. However, the resistance conferring mutation is present in the area and with the potential to be selected under insecticidal pressure.CONCLUSIONSThese results emphasize the need for stronger entomological surveillance in the region, including early detection of house invasion, particularly post-spraying, monitoring for resistance to pyrethroids and the design of integrative control actions that consider both sylvatic foci around domestic settings as well as the bug dispersion dynamics.

Great Wall blocks gene flow

Nature ◽  
2003 ◽  
Author(s):  
HelenR. Pilcher
Keyword(s):  
Gene Flow ◽  
Great Wall
Sign in / Sign up

Export Citation Format

Share Document