Project description:<p>Chronic sleep loss profoundly impacts metabolic health and shortens lifespan, but studies of the mechanisms involved have focused largely on acute sleep deprivation. To identify metabolic consequences of chronically reduced sleep, we conducted unbiased metabolomics on heads of three adult Drosophila short-sleeping mutants with very different mechanisms of sleep loss: fumin (fmn), redeye (rye), and sleepless (sss). Common features included elevated ornithine and polyamines, with lipid, acyl-carnitine, and TCA cycle changes suggesting mitochondrial dysfunction. Studies of excretion demonstrate inefficient nitrogen elimination in adult sleep mutants, likely contributing to their polyamine accumulation. Increasing levels of polyamines, particularly putrescine, promote sleep in control flies but poison sleep mutants. This parallels the broadly enhanced toxicity of high dietary nitrogen load from protein in chronically sleep-restricted Drosophila, including both sleep mutants and flies with hyper-activated wake-promoting neurons. Together, our results implicate nitrogen stress as a novel mechanism linking chronic sleep loss to adverse health outcomes-and perhaps for linking food and sleep homeostasis at the cellular level in healthy organisms.</p>
Project description:A method for the long-term maintenance of germ-free flies was established using aseptic isolators. The methodology effectively and reliably yields large numbers of germ-free flies in homogeneous cultures. Germ-free flies exhibited increased lifespan (only female flies) and decreased egg production, markedly reduced fat storage, less midday sleep, and enhanced aggressiveness (male flies). Fructilactobacillus—a species of fly intestinal microbes—was re-colonized in germ-free flies, and these gnotobiotic flies were successfully maintained for numerous generations. The proteome of those flies were analyzed.
Project description:Genome-wide profiling of rhythmic gene expression has offered new avenues for studying the contribution of circadian clock to diverse biological processes. Sleep has been considered one of the most important physiological processes that are regulated by the circadian clock, however, the effects of chronic sleep loss on rhythmic gene expression remain poorly understood. In the present study, we exploited Drosophila sleep mutants insomniac1 (inc1) and wide awakeD2 (wakeD2) as models for chronic sleep loss. We profiled the transcriptomes of heads collected from 4-week-old wild type flies, inc1 and wakeD2 at timepoints around the clock. Analysis of gene oscillation revealed a substantial loss of rhythmicity in inc1 and wakeD2 compared to wild type flies, with most of the affected genes common to both mutants. The disruption of gene oscillation was not due to changes in average gene expression levels. We also identified a subset of genes whose loss of rhythmicity was shared among animals with chronic sleep loss and old flies, suggesting a contribution of aging to chronic, sleep-loss-induced disruption of gene oscillation.
Project description:Because pink1-mutant flies exhibit a global shutdown of protein synthesis, we decided to measure the levels of individual proteins in adult flies through quantitative proteomics.
Project description:HPLC MS/MS confirmation of lipids found to be heterogeneously distributed between rested and sleep-deprived Drosophila melanogaster brain samples by MALDI MSI. Data belongs to publication "Kv Channels Integrate Sleep Pressure in a Voltage-Gated Lipid Peroxidation Memory"
Project description:Long noncoding RNAs (lncRNAs) are a diverse class of RNAs that are critical for gene regulation, DNA repair and splicing, and have been implicated in cancer, stress response, and development. However, the function of many lncRNAs remains unknown. In Drosophila melanogaster, U snoRNA host gene 4 (Uhg4) encodes an antisense long noncoding RNA that is host to seven small nucleolar RNAs (snoRNAs). Uhg4 is expressed ubiquitously during development and in all adult fly tissues with maximal expression in ovaries; however, it has no annotated function(s). Here, we used CRISPR-Cas9 germline gene editing to generate multiple deletions spanning the promoter region and first exon of Uhg4. Mutant flies were sterile, showed delayed development and decreased viability, and changes in sleep and responses to stress. Whole genome RNA sequencing of Uhg4 deletion flies and their controls identified coregulated genes and genetic interaction networks. Gene ontology analyses highlighted a broad spectrum of biological processes, including morphogenesis, stress response, and regulation of transcription and translation. Thus, Uhg4 is a lncRNA essential for reproduction with pleiotropic effects on multiple fitness traits.