Online insomnia treatment and the reduction of anxiety symptoms as a secondary outcome in a randomised controlled trial: The role of cognitive-behavioural factors.

OBJECTIVE: Insomnia and anxiety commonly co-occur, yet the mechanisms underlying this remain unclear. The current paper describes the impact of an Internet-based intervention for insomnia on anxiety, and explores the influence of two cognitive-behavioural constructs - dysfunctional beliefs about sleep and sleep-threat monitoring. METHODS: A large-scale, 9-week, two-arm randomised controlled trial ( N = 1149) of community-dwelling Australian adults with insomnia and elevated yet subclinical depression symptoms was conducted, comparing a cognitive behavioural therapy-based online intervention for insomnia (Sleep Healthy Using The Internet) with an attention-matched online control intervention (HealthWatch). Symptoms of anxiety were assessed at pretest, posttest, and 6-month follow-up. Dysfunctional beliefs about sleep and sleep threat monitoring were assessed only at pretest. RESULTS: Sleep Healthy Using The Internet led to a greater reduction in anxiety symptoms at both posttest ( t724.27 = -6.77, p < 0.001) and at 6-month follow-up ( t700.67 = -4.27, p < 0.001) than HealthWatch. At posttest and follow-up, this effect was found to moderated by sleep-threat monitoring ( t713.69 = -2.39, p < 0.05 and t694.77 = -2.98, p < 0.01 respectively) but not by dysfunctional beliefs about sleep at either posttest or follow-up ( t717.53 = -0.61, p = 0.55 and t683.79 = 0.22, p = 0.83 respectively). Participants in the Sleep Healthy Using The Internet condition with higher levels of sleep-threat monitoring showed a greater reduction in anxiety than those with lower levels from pretest to posttest, ( t724.27 = -6.77, p < 0.001) and through to 6-month follow-up ( t700.67 = -4.27, p < 0.001). This result remained after controlling for baseline anxiety levels. CONCLUSION: The findings suggest that online cognitive behavioral therapy interventions for insomnia are beneficial for reducing anxiety regardless of people's beliefs about their sleep and insomnia, and this is particularly the case for those with high sleep-threat monitoring. This study also provides further evidence for cognitive models of insomnia.

Evolution of genes and genomes on the Drosophila phylogeny.

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.

In vivo functional analysis of the Drosophila melanogaster nicotinic acetylcholine receptor Dα6 using the insecticide spinosad.

The vinegar fly, Drosophila melanogaster, has been used to identify and manipulate insecticide resistance genes. The advancement of genome engineering technology and the increasing availability of pest genome sequences has increased the predictive and diagnostic capacity of the Drosophila model. The Drosophila model can be extended to investigate the basic biology of the interaction between insecticides and the proteins they target. Recently we have developed an in vivo system that permits the expression and study of key insecticide targets, the nicotinic acetylcholine receptors (nAChRs), in controlled genetic backgrounds. Here this system is used to study the interaction between the insecticide spinosad and a nAChR subunit, Dα6. Reciprocal chimeric subunits were created from Dα6 and Dα7, a subunit that does not respond to spinosad. Using the in vivo system, the Dα6/Dα7 chimeric subunits were tested for their capacity to respond to spinosad. Only the subunits containing the C-terminal region of Dα6 were able to respond to spinosad, thus confirming the importance this region for spinosad binding. A new incompletely dominant, spinosad resistance mechanism that may evolve in pest species is also examined. First generated using chemical mutagenesis, the Dα6(P146S) mutation was recreated using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 system, the first use of this technology to introduce a resistant mutation into a controlled genetic background. Both alleles present with the same incompletely dominant, spinosad resistance phenotype, proving the P146S replacement to be the causal mutation. The proximity of the P146S mutation to the conserved Cys-loop indicates that it may impair the gating of the receptor. The results of this study enhance the understanding of nAChR structure:function relationships.

The Wiggle Index: An Open Source Bioassay to Assess Sub-Lethal Insecticide Response in Drosophila melanogaster.

Toxicological assays measuring mortality are routinely used to describe insecticide response, but sub-lethal exposures to insecticides can select for resistance and yield additional biological information describing the ways in which an insecticide impacts the insect. Here we present the Wiggle Index (WI), a high-throughput method to quantify insecticide response by measuring the reduction in motility during sub-lethal exposures in larvae of the vinegar fly Drosophila melanogaster. A susceptible wild type strain was exposed to the insecticides chlorantraniliprole, imidacloprid, spinosad, and ivermectin. Each insecticide reduced larval motility, but response times and profiles differed among insecticides. Two sets of target site mutants previously identified in mortality studies on the basis of imidacloprid or spinosad resistance phenotypes were tested. In each case the resistant mutant responded significantly less than the control. The WI was also able to detect a spinosad response in the absence of the primary spinosad target site. This response was not detected in mortality assays suggesting that spinosad, like many other insecticides, may have secondary targets affecting behaviour. The ability of the WI to detect changes in insecticide metabolism was confirmed by overexpressing the imidacloprid metabolizing Cyp6g1 gene in digestive tissues or the central nervous system. The data presented here validate the WI as an inexpensive, generic, sub-lethal assay that can complement information gained from mortality assays, extending our understanding of the genetic basis of insecticide response in D. melanogaster.

Translational asymmetry as a sensitive indicator of cadmium stress in plants: a laboratory test with wild-type and mutant Arabidopsis thaliana.

• Translational and bilateral asymmetry have been proposed as sensitive measures of stress in plants, but few studies have addressed the asymmetry-stress association for individuals grown under strictly defined conditions. Here, we assess the impact of cadmium (Cd) stress on various asymmetry measures in a wild-type and mutant strain of Arabidopsis thaliana. • Fitness measures (fresh weight, pod count and shoot length) and developmental stability (DS) measures (bilateral asymmetry and translational asymmetry (TA)) were compared between plants grown under different cadmium concentrations. • Cadmium stress sharply increased TA in both strains but had inconsistent effects on bilateral asymmetry. The TA effects were detected at a Cd concentration when effects on growth and reproduction were not yet evident. • Translational asymmetry, but not bilateral asymmetry, may therefore act as a sensitive indicator of cadmium stress and could be used to assess soil contamination in transplanted A. thaliana.

Copper homeostasis gene discovery in Drosophila melanogaster.

Recent studies have shown a high level of conservation between Drosophila melanogaster and mammalian copper homeostasis mechanisms. These studies have also demonstrated the efficiency with which this species can be used to characterize novel genes, at both the cellular and whole organism level. As a versatile and inexpensive model organism, Drosophila is also particularly useful for gene discovery applications and thus has the potential to be extremely useful in identifying novel copper homeostasis genes and putative disease genes. In order to assess the suitability of Drosophila for this purpose, three screening approaches have been investigated. These include an analysis of the global transcriptional response to copper in both adult flies and an embryonic cell line using DNA microarray analysis. Two mutagenesis-based screens were also utilized. Several candidate copper homeostasis genes have been identified through this work. In addition, the results of each screen were carefully analyzed to identify any factors influencing efficiency and sensitivity. These are discussed here with the aim of maximizing the efficiency of future screens and the most suitable approaches are outlined. Building on this information, there is great potential for the further use of Drosophila for copper homeostasis gene discovery.