English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Background  Malaria mortality rates in sub-Saharan Africa have declined significantly in recent years as a result of increased insecticide-treated bed net (ITN) usage. A major challenge to further progress is the emergence and spread of insecticide resistance alleles in the  Anopheles  mosquito vectors, like  An. coluzzii . A non-synonymous mutation in the  para  voltage-gated sodium channel gene reduces pyrethroid-binding affinity, resulting in knockdown resistance ( kdr ). Metabolic mechanisms of insecticide resistance involving detoxification genes like cytochrome P450 genes, carboxylesterases, and glutathione S-transferases are also important. As some gene activity is tissue-specific and/or environmentally induced, gene regulatory variation may be overlooked when comparing expression from whole mosquito bodies under standard rearing conditions.    Results  We detected complex insecticide resistance in a 2014  An. coluzzii  colony from southern Mali using bottle bioassays. Additional bioassays involving recombinant genotypes from a cross with a relatively susceptible 1995  An. coluzzii  colony from Mali confirmed the importance of  kdr  and associated increased permethrin resistance to the  CYP9K1  locus on the X chromosome. Significant differential expression of  CYP9K1  was not observed among these colonies in Malpighian tubules. However, the P450 gene  CYP6Z1  was overexpressed in resistant individuals following sublethal permethrin exposure and the carboxylesterase gene  COEAE5G  was constitutively overexpressed .Conclusions  The significant P450-related insecticide resistance observed in the 2014  An. coluzzii  colony indicates that ITNs treated with the P450 inhibitor piperonyl butoxide (PBO) would be more effective in this region. The known insecticide resistance gene  CYP6Z1  was differentially expressed exclusively in the context of sublethal permethrin exposure, highlighting the importance of tissue-specificity and environmental conditions in gene expression studies. The increased activity of the carboxylesterase  COEAE5G  in the resistant  An. coluzzii  colony suggests resistance to other insecticides like organophosphates. Additional gene expression studies involving other tissues (e.g. fat body) would provide a more comprehensive view of genes underlying metabolic insecticide resistance in  An. coluzzii  from Mali. Identifying genetic markers linked to these regulatory alleles is an important next step that would substantially improve insecticide resistance surveillance and population genetic studies in this important vector species.    Electronic supplementary material  The online version of this article (10.1186/s13071-018-2817-5) contains supplementary material, which is available to authorized users.

Genetic variation associated with increased insecticide resistance in the malaria mosquito, Anopheles coluzzii