Heat Tolerance Assays Using the Drosophila Activity Monitor System: A Guide to an Executable Application for Data Analysis.

The study of heat tolerance in Drosophila melanogaster has been of particular interest to researchers for decades, with a common approach to assessing heat tolerance being to monitor the time to knockdown (TKD) after exposure to an elevated temperature. Classically, flies are housed in individual vials and placed inside a heated water bath. TKD is then monitored manually by researchers.

HoTDAM! An easy-to-use automated assay expands the inducible thermotolerance phenotype in Drosophila melanogaster: Heat hardening reduces motility.

To quantify heat tolerance in insects, two manual observation measures are typically implemented: the time to physiological collapse at a static noxious temperature (time to knockdown; TKD) or the temperature at which collapse occurs as temperature increases (critical thermal maximum; CT). Both assay modalities focus on physiological collapse, neglecting the prior behavioral processes. In this study, the locomotion response of Drosophila melanogaster to relatively high temperature (39 and 40.

Lipidomic Profiling Reveals Concerted Temporal Patterns of Functionally Related Lipids in Females Following Blood Feeding.

We conducted a lipidomic analysis of the whole body of female mosquitoes at different time points over the course of feeding and reproduction. There were temporal biphasic increases of more than 80% of lipids identified at the time of feeding and from 16 h to 30 h post blood meal (PBM). During these two increases, the abundance of many lipids dropped while body weight remained stable, probably reflecting blood lipid digestion and the synthesis of vitellogenin in this period.

Changes in lipid classes of Drosophila melanogaster in response to selection for three stress traits.

Laboratory selection on environmental stress traits is an evolutionary approach that is informative in the context of understanding stress adaptation. Here we characterize changes in a lipidome of Drosophila melanogaster in lines selected for increased heat (elevated heat knockdown refractoriness), cold (decreased time to recover from chill-coma) and desiccation survival. Selection for desiccation resistance resulted in changes in multiple lipid classes used to characterize a lipidome.

Pyrethroid Susceptibility Has Been Maintained in the Dengue Vector, Aedes aegypti (Diptera: Culicidae), in Queensland, Australia.

Although pesticide resistance is common in insect vectors of human diseases, the evolution of resistance might be delayed if management practices are adopted that limit selection of resistance alleles. Outbreaks of dengue fever have occurred in Queensland, Australia, since the late 1800s, leading to ongoing attempts to control the mosquito vector, Aedes aegypti (L.).

A dataset for assessing temporal changes in gene expression during the aging process of adult Drosophila melanogaster.

A Drosophila melanogaster genome-wide transcriptome dataset is available for studies on temporal patterns of gene expression. Gene expression was measured using two-dye color oligonucleotide arrays derived from Version 2 of the Drosophila Genomics Resource Center. A total of 15,158 oligonucleotide probes corresponded to a high proportion of the coding genes in the genome.

Genome-Wide Gene Expression in relation to Age in Large Laboratory Cohorts of Drosophila melanogaster.

Aging is a complex process characterized by a steady decline in an organism's ability to perform life-sustaining tasks. In the present study, two cages of approximately 12,000 mated Drosophila melanogaster females were used as a source of RNA from individuals sampled frequently as a function of age. A linear model for microarray data method was used for the microarray analysis to adjust for the box effect; it identified 1,581 candidate aging genes.

Methionine restriction extends lifespan of Drosophila melanogaster under conditions of low amino-acid status.

Reduced methionine (Met) intake can extend lifespan of rodents; however, whether this regimen represents a general strategy for regulating aging has been controversial. Here we report that Met restriction extends lifespan in both fruit flies and yeast, and that this effect requires low amino-acid status. Met restriction in Drosophila mimicks the effect of dietary restriction and is associated with decreased reproduction.

Heritability and inter-population differences in lipid profiles of Drosophila melanogaster.

Characterizing and understanding the complex spectrum of lipids in higher organisms lags far behind our analysis of genome and transcriptome sequences. Here we generate and evaluate comprehensive lipid profiles (>200 lipids) of 92 inbred lines from five different Drosophila melanogaster populations. We find that the majority of lipid species are highly heritable, and even lipids with odd-chain fatty acids, which cannot be generated by the fly itself, also have high heritabilities.

Drosophila melanogaster Selection for Survival after Infection with Bacillus cereus Spores: Evolutionary Genetic and Phenotypic Investigations of Respiration and Movement.

Laboratory populations of D. melanogaster have been subjected to selection for survival after live spores of B. cereus were introduced as a pathogenic agent.

Drosophila melanogaster Selection for Survival of Bacillus cereus Infection: Life History Trait Indirect Responses.

To study evolved resistance/tolerance in an insect model, we carried out an experimental evolution study using D. melanogaster and the opportunistic pathogen B. cereus as the agent of selection.

Environmental and genetic perturbations reveal different networks of metabolic regulation.

Progress in systems biology depends on accurate descriptions of biological networks. Connections in a regulatory network are identified as correlations of gene expression across a set of environmental or genetic perturbations. To use this information to predict system behavior, we must test how the nature of perturbations affects topologies of networks they reveal.

Increased transsulfuration mediates longevity and dietary restriction in Drosophila.

The mechanisms through which dietary restriction enhances health and longevity in diverse species are unclear. The transsulfuration pathway (TSP) is a highly conserved mechanism for metabolizing the sulfur-containing amino acids, methionine and cysteine. Here we show that Drosophila cystathionine β-synthase (dCBS), which catalyzes the rate-determining step in the TSP, is a positive regulator of lifespan in Drosophila and that the pathway is required for the effects of diet restriction on animal physiology and lifespan.

Analyses of fruit flies that do not express selenoproteins or express the mouse selenoprotein, methionine sulfoxide reductase B1, reveal a role of selenoproteins in stress resistance.

Selenoproteins are essential in vertebrates because of their crucial role in cellular redox homeostasis, but some invertebrates that lack selenoproteins have recently been identified. Genetic disruption of selenoprotein biosynthesis had no effect on lifespan and oxidative stress resistance of Drosophila melanogaster. In the current study, fruit flies with knock-out of the selenocysteine-specific elongation factor were metabolically labeled with (75)Se; they did not incorporate selenium into proteins and had the same lifespan on a chemically defined diet with or without selenium supplementation.

Bioassays of compounds with potential juvenoid activity on Drosophila melanogaster: juvenile hormone III, bisepoxide juvenile hormone III and methyl farnesoates.

Metabolites of the 6,7,10,11 bisepoxide juvenile hormone III (JHB(3)), and other potential juvenoids, were tested for juvenile hormone activity using early instar or early stage pupae of Drosophila melanogaster. Importantly, methyl farnesoates were tested as they might have JH-like activity on Dipteran juveniles. Larvae were exposed to compounds in medium, or the compounds were applied to white puparia.

A hierarchical Bayesian model for a novel sparse partial diallel crossing design.

Partial diallel crossing designs are in common use among evolutionary geneticists, as well as among plant and animal breeders. When the goal is to make statements about populations represented by a given set of lines, it is desirable to maximize the number of lines sampled given a set number of crosses among them. We propose an augmented round-robin design that accomplishes this.

Overexpression of methionine-R-sulfoxide reductases has no influence on fruit fly aging.

Methionine sulfoxide reductases (Msrs) are enzymes that repair oxidized methionine residues in proteins. This function implicated Msrs in antioxidant defense and the regulation of aging. There are two known Msr types in animals: MsrA specific for the reduction of methionine-S-sulfoxide, and MsrB that catalyzes the reduction of methionine-R-sulfoxide.

Natural genetic variation in transcriptome reflects network structure inferred with major effect mutations: insulin/TOR and associated phenotypes in Drosophila melanogaster.

Background: A molecular process based genotype-to-phenotype map will ultimately enable us to predict how genetic variation among individuals results in phenotypic alterations. Building such a map is, however, far from straightforward. It requires understanding how molecular variation re-shapes developmental and metabolic networks, and how the functional state of these networks modifies phenotypes in genotype specific way.

An evolutionary expressed sequence tag analysis of Drosophila spermatheca genes.

This study investigates genes enriched for expression in the spermatheca, the long-term sperm storage organ (SSO) of female Drosophila. SSO genes are likely to play an important role in processes of sexual selection such as sperm competition and cryptic female choice. Although there is keen interest in the mechanisms of sexual selection at the molecular level, very little is known about the female genes that are involved.

Longevity-fertility trade-offs in the tephritid fruit fly, Anastrepha ludens, across dietary-restriction gradients.

Although it is widely known that dietary restriction (DR) not only extends the longevity of a wide range of species but also reduces their reproductive output, the interrelationship of DR, longevity extension and reproduction is not well understood in any organism. Here we address the question: 'Under what nutritional conditions do the longevity-enhancing effects resulting from food restriction either counteract, complement or reinforce the mortality costs of reproduction? To answer this question we designed a fine-grained DR study involving 4800 individuals of the tephritid fruit fly, Anastrepha ludens, in which we measured sex-specific survival and daily reproduction in females in each of 20 different treatments (sugar : yeast ratios) plus 4 starvation controls. The database generated from this 3-year study consisted of approximately 100 000 life-days for each sex and 750 000 eggs distributed over the reproductive lives of 2400 females.

Feeding Drosophila a biotin-deficient diet for multiple generations increases stress resistance and lifespan and alters gene expression and histone biotinylation patterns.

Energy restriction increases stress resistance and lifespan in Drosophila melanogaster and other species. The roles of individual nutrients in stress resistance and longevity are largely unknown. The vitamin biotin is a potential candidate for mediating these effects, given its known roles in stress signaling and gene regulation by epigenetic mechanisms, i.

Superoxide dismutase activities in long-lived Drosophila melanogaster females: chico1 genotypes and dietary dilution.

Superoxide dismutase (SOD) activities were determined for dietary dilution conditions that extend the life span of Drosophila melanogaster. The hypothesis motivating this research was that elevated SOD activity is associated with increased life span resulting from flies being held on a restricted diet. SOD activities were also measured for chico (1) which is a mutation in the insulin receptor substrate protein gene associated with life span extension.

The cost of reproduction: the devil in the details.

The cost of reproduction is of fundamental importance in life-history evolution. However, our understanding of its mechanistic basis has been limited by a lack of detailed functional information at all biological levels. Here, we identify, evaluate and integrate recent studies in five areas examining the proximate mechanisms underlying the cost of reproduction.

Environmental stress and reproduction in Drosophila melanogaster: starvation resistance, ovariole numbers and early age egg production.

Background: The Y model of resource allocation predicts a tradeoff between reproduction and survival. Environmental stress could affect a tradeoff between reproduction and survival, but the physiological mechanisms underlying environmental mediation of the tradeoff are largely unknown. One example is the tradeoff between starvation resistance and early fecundity.