Detection and quantitation of copy number variation in the voltage-gated sodium channel gene of the mosquito Culex quinquefasciatus

Insecticide resistance is typically associated with alterations to the insecticidal target-site or with gene expression variation at loci involved in insecticide detoxification. In some species copy number variation (CNV) of target site loci (e.g. the Ace-1 target site of carbamate insecticides) or detoxification genes has been implicated in the resistance phenotype. We show that field-collected Ugandan Culex quinquefasciatus display CNV for the voltage-gated sodium channel gene (Vgsc), target-site of pyrethroid and organochlorine insecticides. In order to develop field-applicable diagnostics for Vgsc CN, and as a prelude to investigating the possible association of CN with insecticide resistance, three assays were compared for their accuracy in CN estimation in this species. The gold standard method is droplet digital PCR (ddPCR), however, the hardware is prohibitively expensive for widespread utility. Here, ddPCR was compared to quantitative PCR (qPCR) and pyrosequencing. Across all platforms, CNV was detected in ≈10% of mosquitoes, corresponding to three or four copies (per diploid genome). ddPCR and qPCR-Std-curve yielded similar predictions for Vgsc CN, indicating that the qPCR protocol developed here can be applied as a diagnostic assay, facilitating monitoring of Vgsc CN in wild populations and the elucidation of association between the Vgsc CN and insecticide resistance

Whole-Genome Expression Analysis in the Third Instar Larval Midgut of Drosophila melanogaster

Survival of insects on a substrate containing toxic substances such as plant secondary metabolites or insecticides is dependent on the metabolism or excretion of those xenobiotics. The primary sites of xenobiotic metabolism are the midgut, Malpighian tubules, and fat body. In general, gene expression in these organs is reported for the entire tissue by online databases, but several studies have shown that gene expression within the midgut is compartmentalized. Here, RNA sequencing is used to investigate whole-genome expression in subsections of third instar larval midguts of Drosophila melanogaster. The data support functional diversification in subsections of the midgut. Analysis of the expression of gene families that are implicated in the metabolism of xenobiotics suggests that metabolism may not be uniform along the midgut. These data provide a starting point for investigating gene expression and xenobiotic metabolism and other functions of the larval midgut

High-Quality Assemblies for Three Invasive Social Wasps from the Vespula Genus

Social wasps of the genus Vespula have spread to nearly all landmasses worldwide and have become significant pests in their introduced ranges, affecting economies and biodiversity. Comprehensive genome assemblies and annotations for these species are required to develop the next generation of control strategies and monitor existing chemical control. We sequenced and annotated the genomes of the common wasp (Vespula vulgaris), German wasp (Vespula germanica), and the western yellowjacket (Vespula pensylvanica). Our chromosome-level Vespula assemblies each contain 176-179 Mb of total sequence assembled into 25 scaffolds, with 10-200 unanchored scaffolds, and 16,566-18,948 genes. We annotated gene sets relevant to the applied management of invasive wasp populations, including genes associated with spermatogenesis and development, pesticide resistance, olfactory receptors, immunity and venom. These genomes provide evidence for active DNA methylation in Vespidae and tandem duplications of venom genes. Our genomic resources will contribute to the development of next-generation control strategies, and monitoring potential resistance to chemical control

Erratum: High-quality assemblies for three invasive social wasps from the vespula genus (G3: Genes, Genomes, Genetics (2020) 10 (3479-3488) DOI: 10.1534/g3.120.401579)

In the originally published version of this manuscript, funding information and disclosures were omitted. The following information should have been included after the Acknowledgments section. Funding This project was supported by Genomics Aotearoa (to PKD) and the Biological Heritage National Science Challenge (to PJL) both funded by the Ministry of Business Innovation and Employment (Hı¯kina Whakatutuki), Government of New Zealand, as well as US National Science Foundation Grant #1655963 and UC Riverside Seed Grant to JP and EWR; Dovetail Genomics Matching Funds Grant to JP. Availability of data and materials Raw reads are hosted in the NCBI Sequence Read Archive under accession PRJNA643352. The version of the assemblies and annotations described in this paper is hosted on Zenodo under DOI 10.5281/zenodo.4001020. The genomes and annotations have also been uploaded to GenBank under accessions JACSDY000000000 (Vespula pensylvanica), JACSDZ000000000 (Vespula germanica) and JACSEA000000000 (Vespula vulgaris). The annotations used in this paper and the annotations hosted by GenBank differ because records were removed to pass NCBI validation. Authors' contributions PJL and PKD conceived and designed the project. All authors aided in obtaining and analysing the genomic data. PJL, PKD, TWRH, JG, EJR and EJD wrote the manuscript draft, and all authors participated in the revision of the final version. All authors read and approved the final manuscript. Ethics approval and consent to participate Common wasps (V. vulgaris) were collected under the permit National Authorisation Number 38337-RES from the Department of Conservation in New Zealand. Samples of other wasps were collected from private land where no permit was required. No other ethical approval was required. Competing interests The authors declare that they have no competing interests. The above information has now been updated in the online article