Mosquito-borne diseases, the most well known of which is malaria, are among the leading causes of human deaths worldwide. Vector control is a very important part of the global strategy for management of mosquito-associated diseases, and insecticide application is the most important component in this effort. However, mosquito-borne diseases are now resurgent, largely because of the insecticide resistance that has developed in mosquito vectors and the drug resistance of pathogens. A large number of studies have shown that multiple, complex resistance mechanisms-in particular, increased metabolic detoxification of insecticides and decreased sensitivity of the target proteins-or genes are likely responsible for insecticide resistance. Gene overexpression and amplification, and mutations in protein-coding-gene regions, have frequently been implicated as well. However, no comprehensive understanding of the resistance mechanisms or regulation involved has yet been developed. This article reviews current knowledge of the molecular mechanisms, genes, gene interactions, and gene regulation governing the development of insecticide resistance in mosquitoes and discusses the potential impact of the latest research findings on the basic and practical aspects of mosquito resistance research.

Culex quinquefasciatus (the Southern house mosquito) is an important mosquito vector of viruses such as West Nile virus and St. Louis encephalitis virus as well of nematodes that cause lymphatic filariasis. It is one species within the Culex pipiens species complex and enjoys a distribution throughout tropical and temperate climates of the world. The ability of C. quinquefasciatus to take blood meals from birds, livestock and humans contributes to its ability to vector pathogens between species. We describe the genomic sequence of C. quinquefasciatus, its repertoire of 18,883 protein-coding genes is 22% larger than Ae. aegypti and 52% larger than An. gambiae with multiple gene family expansions including olfactory and gustatory receptors, salivary gland genes, and genes associated with xenobiotic detoxification.

BackgroundAdult house flies, Musca domestica L., are mechanical vectors of more than 100 devastating diseases that have severe consequences for human and animal health. House fly larvae play a vital role as decomposers of animal wastes, and thus live in intimate association with many animal pathogens.ResultsWe have sequenced and analyzed the genome of the house fly using DNA from female flies. The sequenced genome is 691 Mb. Compared with Drosophila melanogaster, the genome contains a rich resource of shared and novel protein coding genes, a significantly higher amount of repetitive elements, and substantial increases in copy number and diversity of both the recognition and effector components of the immune system, consistent with life in a pathogen-rich environment. There are 146 P450 genes, plus 11 pseudogenes, in M. domestica, representing a significant increase relative to D. melanogaster and suggesting the presence of enhanced detoxification in house flies. Relative to D. melanogaster, M. domestica has also evolved an expanded repertoire of chemoreceptors and odorant binding proteins, many associated with gustation.ConclusionsThis represents the first genome sequence of an insect that lives in intimate association with abundant animal pathogens. The house fly genome provides a rich resource for enabling work on innovative methods of insect control, for understanding the mechanisms of insecticide resistance, genetic adaptation to high pathogen loads, and for exploring the basic biology of this important pest. The genome of this species will also serve as a close out-group to Drosophila in comparative genomic studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-014-0466-3) contains supplementary material, which is available to authorized users.

Integrating biological components into artificial devices establishes an interface to understand and imitate the superior functionalities of the living systems. One challenge in developing biohybrid nanosystems mimicking the gating function of the biological ion channels is to enhance the gating efficiency of the man-made systems. Herein, we demonstrate a DNA supersandwich and ATP gated nanofluidic device that exhibits high ON-OFF ratios (up to 10(6)) and a perfect electric seal at its closed state (~GΩ). The ON-OFF ratio is distinctly higher than existing chemically modified nanofluidic gating systems. The gigaohm seal is comparable with that required in ion channel electrophysiological recording and some lipid bilayer-coated nanopore sensors. The gating function is implemented by self-assembling DNA supersandwich structures into solid-state nanochannels (open-to-closed) and their disassembly through ATP-DNA binding interactions (closed-to-open). On the basis of the reversible and all-or-none electrochemical switching properties, we further achieve the IMPLICATION logic operations within the nanofluidic structures. The present biohybrid nanofluidic device translates molecular events into electrical signals and indicates a built-in signal amplification mechanism for future nanofluidic biosensing and modular DNA computing on solid-state substrates.

The weak van der Waals interactions enable ion‐intercalation‐type hosts to be ideal pseudocapacitive materials for energy storage. Here, a methodology for the preparation of hydrated vanadium dioxide nanoribbon (HVO) with moderate transport pathways is proposed. Out of the ordinary, the intercalation pseudocapacitive reaction mechanism is discovered for HVO, which powers high‐rate capacitive charge storage compared with the battery‐type intercalation reaction. The main factor is that the defective crystalline structure provides suitable ambient spacing for rapidly accommodating and transporting cations. As a result, the HVO delivers a fast Zn2+ ion diffusion coefficient and a low Zn2+ diffusion barrier. The electrochemical results with intercalation pseudocapacitance demonstrate a high reversible capacity of 396 mAh g−1 at 0.05 A g−1, and even maintain 88 mAh g−1 at a high current density of 50 A g−1.

SummaryImprovement of grain yield is an essential long-term goal of maize (Zea mays) breeding to meet continual and increasing food demands worldwide, but the genetic basis remains unclear.We used 10 different recombination inbred line (RIL) populations genotyped with highdensity markers and phenotyped in multiple environments to dissect the genetic architecture of maize ear traits.Three methods were used to map the quantitative trait loci (QTLs) affecting ear traits. We found 17-34 minor-or moderate-effect loci that influence ear traits, with little epistasis and environmental interactions, totally accounting for 55.4-82% of the phenotypic variation. Four novel QTLs were validated and fine mapped using candidate gene association analysis, expression QTL analysis and heterogeneous inbred family validation.The combination of multiple different populations is a flexible and manageable way to collaboratively integrate widely available genetic resources, thereby boosting the statistical power of QTL discovery for important traits in agricultural crops, ultimately facilitating breeding programs.

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Here we report a study of the 204 P450 genes in the whole genome sequence of larvae and adult Culex quinquefasciatus mosquitoes. The expression profiles of the P450 genes were compared for susceptible (S-Lab) and resistant mosquito populations, two different field populations of mosquitoes (HAmCq and MAmCq), and field parental mosquitoes (HAmCq G0 and MAmCqG0) and their permethrin selected offspring (HAmCq G8 and MAmCqG6). While the majority of the P450 genes were expressed at a similar level between the field parental strains and their permethrin selected offspring, an up- or down-regulation feature in the P450 gene expression was observed following permethrin selection. Compared to their parental strains and the susceptible S-Lab strain, HAmCqG8 and MAmCqG6 were found to up-regulate 11 and 6% of total P450 genes in larvae and 7 and 4% in adults, respectively, while 5 and 11% were down-regulated in larvae and 4 and 2% in adults. Although the majority of these up- and down-regulated P450 genes appeared to be developmentally controlled, a few were either up- or down-regulated in both the larvae and adult stages. Interestingly, a different gene set was found to be up- or down-regulated in the HAmCqG8 and MAmCqG6 mosquito populations in response to insecticide selection. Several genes were identified as being up- or down-regulated in either the larvae or adults for both HAmCqG8 and MAmCqG6; of these, CYP6AA7 and CYP4C52v1 were up-regulated and CYP6BY3 was down-regulated across the life stages and populations of mosquitoes, suggesting a link with the permethrin selection in these mosquitoes. Taken together, the findings from this study indicate that not only are multiple P450 genes involved in insecticide resistance but up- or down-regulation of P450 genes may also be co-responsible for detoxification of insecticides, insecticide selection, and the homeostatic response of mosquitoes to changes in cellular environment.