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Dietary restriction (DR) is a potent method to enhance lifespan and healthspan, but individual responses are influenced by genetic variations. Understanding how metabolism-related genetic differences impact longevity and healthspan are unclear. To investigate this, we used metabolites as markers to reveal how different genotypes respond to diet to influence longevity and healthspan traits. We analyzed data from Drosophila Genetic Reference Panel (DGRP) strains raised under AL and DR conditions, combining metabolomic, phenotypic, and genome-wide information. We employed two computational and complementary methods across species-random forest modeling within the DGRP as our primary analysis and Mendelian randomization in human cohorts as a secondary analysis. We pinpointed key traits with cross-species relevance as well as underlying heterogeneity and pleiotropy that influence lifespan and healthspan. Notably, orotate was linked to parental age at death in humans and blocked the DR lifespan extension in flies, while threonine supplementation extended lifespan, in a strain- and sex-specific manner. Thus, utilizing natural genetic variation data from flies and humans, we employed a systems biology approach to elucidate potential therapeutic pathways and metabolomic targets for diet-dependent changes in lifespan and healthspan.

Cells employ diverse strategies to repair double-strand breaks (DSBs), a dangerous form of DNA damage that threatens genome integrity. Eukaryotic nuclei consist of different chromatin environments, each displaying distinct molecular and biophysical properties that can significantly influence the DSB-repair process. DSBs arising in the compact and silenced heterochromatin domains have been found to move to the heterochromatin periphery in mouse and Drosophila to prevent aberrant recombination events. However, it is poorly understood how chromatin components, such as histone post-translational modifications, contribute to these DSB movements within heterochromatin. Using irradiation as well as locus-specific DSB induction in Drosophila tissues and cultured cells, we find enrichment of histone H3 lysine 9 acetylation (H3K9ac) at DSBs in heterochromatin but not euchromatin. We find this increase is mediated by the histone acetyltransferase dGcn5, which rapidly localizes to heterochromatic DSBs. Moreover, we demonstrate that in the absence of dGcn5, heterochromatic DSBs display impaired recruitment of the SUMO E3 ligase Nse2/Qjt and fail to relocate to the heterochromatin periphery to complete repair. In summary, our results reveal a previously unidentified role for dGcn5 and H3K9ac in heterochromatic DSB repair and underscore the importance of differential chromatin responses at heterochromatic and euchromatic DSBs to promote safe repair.

Tumors can induce systemic disturbances in distant organs, leading to physiological changes that enhance host morbidity. In Drosophila cancer models, tumors have been known for decades to cause hypervolemic "bloating" of the abdominal cavity. Here we use allograft and transgenic tumors to show that hosts display fluid retention associated with autonomously defective secretory capacity of fly renal tubules, which function analogous to those of the human kidney. Excretion from these organs is blocked by abnormal cells that originate from inappropriate activation of normally quiescent renal stem cells (RSCs). Blockage is initiated by IL-6-like oncokines that perturb renal water-transporting cells and trigger a damage response in RSCs that proceeds pathologically. Thus, a chronic inflammatory state produced by the tumor causes paraneoplastic fluid dysregulation by altering cellular homeostasis of host renal units.

The fruit fly Drosophila melanogaster has emerged as a key model organism in neuroscience, in large part due to the concentration of collaboratively generated molecular, genetic and digital resources available for it. Here we complement the approximately 140,000 neuron FlyWire whole-brain connectome1 with a systematic and hierarchical annotation of neuronal classes, cell types and developmental units (hemilineages). Of 8,453 annotated cell types, 3,643 were previously proposed in the partial hemibrain connectome2, and 4,581 are new types, mostly from brain regions outside the hemibrain subvolume. Although nearly all hemibrain neurons could be matched morphologically in FlyWire, about one-third of cell types proposed for the hemibrain could not be reliably reidentified. We therefore propose a new definition of cell type as groups of cells that are each quantitatively more similar to cells in a different brain than to any other cell in the same brain, and we validate this definition through joint analysis of FlyWire and hemibrain connectomes. Further analysis defined simple heuristics for the reliability of connections between brains, revealed broad stereotypy and occasional variability in neuron count and connectivity, and provided evidence for functional homeostasis in the mushroom body through adjustments of the absolute amount of excitatory input while maintaining the excitation/inhibition ratio. Our work defines a consensus cell type atlas for the fly brain and provides both an intellectual framework and open-source toolchain for brain-scale comparative connectomics.

Dendrite defects and loss are early cellular alterations observed across neurodegenerative diseases that play a role in early disease pathogenesis. Dendrite degeneration can be modeled by expressing pathogenic polyglutamine disease transgenes in Drosophila neurons in vivo. Here, we show that we can protect against dendrite loss in neurons modeling neurodegenerative polyglutamine diseases through injury to a single primary dendrite branch. We find that this neuroprotection is specific to injury-induced activation of dendrite regeneration: neither injury to the axon nor injury just to surrounding tissues induces this response. We show that the mechanism of this regenerative response is stabilization of the actin (but not microtubule) cytoskeleton. We also demonstrate that this regenerative response may extend to other neurodegenerative diseases. Together, we provide evidence that activating dendrite regeneration pathways has the potential to slow-or even reverse-dendrite loss in neurodegenerative disease.

Connections between neurons can be mapped by acquiring and analysing electron microscopic brain images. In recent years, this approach has been applied to chunks of brains to reconstruct local connectivity maps that are highly informative1-6, but nevertheless inadequate for understanding brain function more globally. Here we present a neuronal wiring diagram of a whole brain containing 5 × 107 chemical synapses7 between 139,255 neurons reconstructed from an adult female Drosophila melanogaster8,9. The resource also incorporates annotations of cell classes and types, nerves, hemilineages and predictions of neurotransmitter identities10-12. Data products are available for download, programmatic access and interactive browsing and have been made interoperable with other fly data resources. We derive a projectome-a map of projections between regions-from the connectome and report on tracing of synaptic pathways and the analysis of information flow from inputs (sensory and ascending neurons) to outputs (motor, endocrine and descending neurons) across both hemispheres and between the central brain and the optic lobes. Tracing from a subset of photoreceptors to descending motor pathways illustrates how structure can uncover putative circuit mechanisms underlying sensorimotor behaviours. The technologies and open ecosystem reported here set the stage for future large-scale connectome projects in other species.

A catalogue of neuronal cell types has often been called a 'parts list' of the brain1, and regarded as a prerequisite for understanding brain function2,3. In the optic lobe of Drosophila, rules of connectivity between cell types have already proven to be essential for understanding fly vision4,5. Here we analyse the fly connectome to complete the list of cell types intrinsic to the optic lobe, as well as the rules governing their connectivity. Most new cell types contain 10 to 100 cells, and integrate information over medium distances in the visual field. Some existing type families (Tm, Li, and LPi)6-10 at least double in number of types. A new serpentine medulla (Sm) interneuron family contains more types than any other. Three families of cross-neuropil types are revealed. The consistency of types is demonstrated by analysing the distances in high-dimensional feature space, and is further validated by algorithms that select small subsets of discriminative features. We use connectivity to hypothesize about the functional roles of cell types in motion, object and colour vision. Connectivity with 'boundary types' that straddle the optic lobe and central brain is also quantified. We showcase the advantages of connectomic cell typing: complete and unbiased sampling, a rich array of features based on connectivity and reduction of the connectome to a substantially simpler wiring diagram of cell types, with immediate relevance for brain function and development.

Many animals use visual information to navigate1-4, but how such information is encoded and integrated by the navigation system remains incompletely understood. In Drosophila melanogaster, EPG neurons in the central complex compute the heading direction5 by integrating visual input from ER neurons6-12, which are part of the anterior visual pathway (AVP)10,13-16. Here we densely reconstruct all neurons in the AVP using electron-microscopy data17. The AVP comprises four neuropils, sequentially linked by three major classes of neurons: MeTu neurons10,14,15, which connect the medulla in the optic lobe to the small unit of the anterior optic tubercle (AOTUsu) in the central brain; TuBu neurons9,16, which connect the AOTUsu to the bulb neuropil; and ER neurons6-12, which connect the bulb to the EPG neurons. On the basis of morphologies, connectivity between neural classes and the locations of synapses, we identify distinct information channels that originate from four types of MeTu neurons, and we further divide these into ten subtypes according to the presynaptic connections in the medulla and the postsynaptic connections in the AOTUsu. Using the connectivity of the entire AVP and the dendritic fields of the MeTu neurons in the optic lobes, we infer potential visual features and the visual area from which any ER neuron receives input. We confirm some of these predictions physiologically. These results provide a strong foundation for understanding how distinct sensory features can be extracted and transformed across multiple processing stages to construct higher-order cognitive representations.

Eicosanoids are a class of molecules derived from C20 polyunsaturated fatty acids (PUFAs) that play a vital role in mammalian and insect biological systems, including development, reproduction, and immunity. Recent research has shown that insects have significant but lower levels of C20 PUFAs in circulation in comparison to C18 PUFAs. It has been previously hypothesized in insects that eicosanoids are synthesized from C18 precursors, such as linoleic acid (LA), to produce downstream eicosanoids. In this study, we show that introduction of arachidonic acid (AA) stimulates production of cyclooxygenase, lipoxygenase, and cytochrome P450-derived eicosanoids. Downstream immune readouts showed that LA stimulates phagocytosis by hemocytes, while both LA and AA stimulate increased antimicrobial peptide production when D. melanogaster is exposed to a heat-killed bacterial pathogen. In totality, this work identifies PUFAs that are involved in insect immunity and adds evidence to the notion that Drosophila utilizes immunostimulatory lipid signaling to mitigate bacterial infections. Our understanding of immune signaling in the fly and its analogies to mammalian systems will increase the power and value of Drosophila as a model organism in immune studies.

During animal development, the spatiotemporal properties of molecular events largely determine the biological outcomes. Conventional gene analysis methods lack the spatiotemporal resolution for precise dissection of developmental mechanisms. Although optogenetic tools exist for manipulating designer proteins in cultured cells, few have been successfully applied to endogenous proteins in live animals. Here, we report OptoTrap, a light-inducible clustering system for manipulating endogenous proteins of diverse sizes, subcellular locations, and functions in Drosophila. This system turns on fast, is reversible in minutes or hours, and contains variants optimized for neurons and epithelial cells. By using OptoTrap to disrupt microtubules and inhibit kinesin-1 in neurons, we show that microtubules support the growth of highly dynamic dendrites and that kinesin-1 is required for patterning of low- and high-order dendritic branches in differential spatiotemporal domains. OptoTrap allows for precise manipulation of endogenous proteins in a spatiotemporal manner and thus holds promise for studying developmental mechanisms in a wide range of cell types and developmental stages.

To survive adverse environments, many animals enter a dormant state such as hibernation, dauer, or diapause. Various Drosophila species undergo adult reproductive diapause in response to cool temperatures and/or short day-length. While flies are less active during diapause, it is unclear how adverse environmental conditions affect circadian rhythms and sleep. Here we show that in diapause-inducing cool temperatures, Drosophila melanogaster exhibit altered circadian activity profiles, including severely reduced morning activity and an advanced evening activity peak. Consequently, the flies have a single activity peak at a time similar to when nondiapausing flies take a siesta. Temperatures ≤15 °C, rather than photoperiod, primarily drive this behavior. At cool temperatures, flies rapidly enter a deep-sleep state that lacks the sleep cycles of flies at higher temperatures and require high levels of stimulation for arousal. Furthermore, we show that at 25 °C, flies prefer to siesta in the shade, a preference that is virtually eliminated at 10 °C. Resting in the shade is driven by an aversion to blue light that is sensed by Rhodopsin 7 outside of the eyes. Flies at 10 °C show neuronal markers of elevated sleep pressure, including increased expression of Bruchpilot and elevated Ca2+ in the R5 ellipsoid body neurons. Therefore, sleep pressure might overcome blue light aversion. Thus, at the same temperatures that cause reproductive arrest, preserve germline stem cells, and extend lifespan, D. melanogaster are prone to deep sleep and exhibit dramatically altered, yet rhythmic, daily activity patterns.

Organisms adapt to unfavorable seasonal conditions to survive. These seasonal adaptations rely on the correct interpretation of environmental cues such as photoperiod, and temperature. Genetic studies in several organisms, including the genetic powerhouse Drosophila melanogaster, indicate that circadian clock components, such as period and timeless, are involved in photoperiodic-dependent seasonal adaptations, but our understanding of this process is far from complete. In particular, the role of temperature as a key factor to complement photoperiodic response is not well understood. The development of new sequencing technologies has proven extremely useful in understanding the plastic changes that the clock and other cellular components undergo in different environmental conditions, including changes in gene expression and alternative splicing. This article discusses the integration of photoperiod and temperature for seasonal biology as well as downstream molecular and cellular pathways involved in the regulation of physiological adaptations that occur with changing seasons. We focus our discussion on the current understanding of the involvement of the molecular clock and the circadian clock neuronal circuits in these adaptations in D. melanogaster.

Although the effects of genetic and environmental perturbations on multicellular organisms are rarely restricted to single phenotypic layers, our current understanding of how developmental programs react to these challenges remains limited. Here, we have examined the phenotypic consequences of disturbing the bicoid regulatory network in early Drosophila embryos. We generated flies with two extra copies of bicoid, which causes a posterior shift of the networks regulatory outputs and a decrease in fitness. We subjected these flies to EMS mutagenesis, followed by experimental evolution. After only 8-15 generations, experimental populations have normalized patterns of gene expression and increased survival. Using a phenomics approach, we find that populations were normalized through rapid increases in embryo size driven by maternal changes in metabolism and ovariole development. We extend our results to additional populations of flies, demonstrating predictability. Together, our results necessitate a broader view of regulatory network evolution at the systems level.

The mammalian brain implements sophisticated sensory processing algorithms along multilayered (deep) neural networks. Strategies that insects use to meet similar computational demands, while relying on smaller nervous systems with shallow architectures, remain elusive. Using Drosophila as a model, we uncover the algorithmic role of odor preprocessing by a shallow network of compartmentalized olfactory receptor neurons. Each compartment operates as a ratiometric unit for specific odor-mixtures. This computation arises from a simple mechanism: electrical coupling between two differently sized neurons. We demonstrate that downstream synaptic connectivity is shaped to optimally leverage amplification of a hedonic value signal in the periphery. Furthermore, peripheral preprocessing is shown to markedly improve novel odor classification in a higher brain center. Together, our work highlights a far-reaching functional role of the sensory periphery for downstream processing. By elucidating the implementation of powerful computations by a shallow network, we provide insights into general principles of efficient sensory processing algorithms.

In many organisms, most notably Drosophila, homologous chromosomes associate in somatic cells, a phenomenon known as somatic pairing, which takes place without double strand breaks or strand invasion, thus requiring some other mechanism for homologs to recognize each other. Several studies have suggested a "specific button" model, in which a series of distinct regions in the genome, known as buttons, can associate with each other, mediated by different proteins that bind to these different regions. Here, we use computational modeling to evaluate an alternative "button barcode" model, in which there is only one type of recognition site or adhesion button, present in many copies in the genome, each of which can associate with any of the others with equal affinity. In this model, buttons are nonuniformly distributed, such that alignment of a chromosome with its correct homolog, compared with a nonhomolog, is energetically favored; since to achieve nonhomologous alignment, chromosomes would be required to mechanically deform in order to bring their buttons into mutual register. By simulating randomly generated nonuniform button distributions, many highly effective button barcodes can be easily found, some of which achieve virtually perfect pairing fidelity. This model is consistent with existing literature on the effect of translocations of different sizes on homolog pairing. We conclude that a button barcode model can attain highly specific homolog recognition, comparable to that seen in actual cells undergoing somatic homolog pairing, without the need for specific interactions. This model may have implications for how meiotic pairing is achieved.

Salt (NaCl), is an essential nutrient for survival, while excessive salt can be detrimental. In the fruit fly, Drosophila melanogaster, internal taste organs in the pharynx are critical gatekeepers impacting the decision to accept or reject a food. Currently, our understanding of the mechanism through which pharyngeal gustatory receptor neurons (GRNs) sense high salt are rudimentary. Here, we found that a member of the ionotropic receptor family, Ir60b, is expressed exclusively in a pair of GRNs activated by high salt. Using a two-way choice assay (DrosoX) to measure ingestion volume, we demonstrate that IR60b and two co-receptors IR25a and IR76b are required to prevent high salt consumption. Mutants lacking external taste organs but retaining the internal taste organs in the pharynx exhibit much higher salt avoidance than flies with all taste organs but missing the three IRs. Our findings highlight the vital role for IRs in a pharyngeal GRN to control ingestion of high salt.

Pangenome references address biases of reference genomes by storing a representative set of diverse haplotypes and their alignment, usually as a graph. Alternate alleles determined by variant callers can be used to construct pangenome graphs, but advances in long-read sequencing are leading to widely available, high-quality phased assemblies. Constructing a pangenome graph directly from assemblies, as opposed to variant calls, leverages the graph's ability to represent variation at different scales. Here we present the Minigraph-Cactus pangenome pipeline, which creates pangenomes directly from whole-genome alignments, and demonstrate its ability to scale to 90 human haplotypes from the Human Pangenome Reference Consortium. The method builds graphs containing all forms of genetic variation while allowing use of current mapping and genotyping tools. We measure the effect of the quality and completeness of reference genomes used for analysis within the pangenomes and show that using the CHM13 reference from the Telomere-to-Telomere Consortium improves the accuracy of our methods. We also demonstrate construction of a Drosophila melanogaster pangenome.

How a developing organ robustly coordinates the cellular mechanics and growth to reach a final size and shape remains poorly understood. Through iterations between experiments and model simulations that include a mechanistic description of interkinetic nuclear migration, we show that the local curvature, height, and nuclear positioning of cells in the Drosophila wing imaginal disc are defined by the concurrent patterning of actomyosin contractility, cell-ECM adhesion, ECM stiffness, and interfacial membrane tension. We show that increasing cell proliferation via different growth-promoting pathways results in two distinct phenotypes. Triggering proliferation through insulin signaling increases basal curvature, but an increase in growth through Dpp signaling and Myc causes tissue flattening. These distinct phenotypic outcomes arise from differences in how each growth pathway regulates the cellular cytoskeleton, including contractility and cell-ECM adhesion. The coupled regulation of proliferation and cytoskeletal regulators is a general strategy to meet the multiple context-dependent criteria defining tissue morphogenesis.

Aminergic signaling is known to play a critical role in regulating female reproductive processes in both mammals and insects. In Drosophila, the ortholog of noradrenaline, octopamine, is required for ovulation as well as several other female reproductive processes. Two octopamine receptors have already been shown to be expressed in the Drosophila reproductive tract and to be required for egg-laying: OAMB and Octβ2R. The Drosophila genome contains 4 additional octopamine receptors-Octα2R, Octβ1R, Octβ3R, and Oct-TyrR-but their cellular patterns of expression in the reproductive tract and potential contribution(s) to egg-laying are not known. In addition, the mechanisms by which OAMB and Octβ2R regulate reproduction are incompletely understood. Using a panel of MiMIC Gal4 lines, we show that Octα2R, Octβ1R, Octβ3R, and Oct-TyrR receptors are not detectable in either epithelium or muscle but are clearly expressed in neurons within the female fly reproductive tract. Optogenetic activation of neurons that express at least 3 types of octopamine receptors stimulates contractions in the lateral oviduct. We also find that octopamine stimulates calcium transients in the sperm storage organs and that its effects in spermathecal, secretory cells, can be blocked by knock-down of OAMB. These data extend our understanding of the pathways by which octopamine regulates egg-laying in Drosophila and raise the possibility that multiple octopamine receptor subtypes could play a role in this process.

O-linked β-N-acetylglucosamine (O-GlcNAcylation) is a dynamic post-translational modification that regulates thousands of proteins and almost all cellular processes. Aberrant O-GlcNAcylation has been associated with numerous diseases, including cancer, neurodegenerative diseases, cardiovascular diseases, and type 2 diabetes. O-GlcNAcylation is highly nutrient-sensitive since it is dependent on UDP-GlcNAc, the end product of the hexosamine biosynthetic pathway (HBP). We previously observed daily rhythmicity of protein O-GlcNAcylation in a Drosophila model that is sensitive to the timing of food consumption. We showed that the circadian clock is pivotal in regulating daily O-GlcNAcylation rhythms given its control of the feeding-fasting cycle and hence nutrient availability. Interestingly, we reported that the circadian clock also modulates daily O-GlcNAcylation rhythm by regulating molecular mechanisms beyond the regulation of food consumption time. A large body of work now indicates that O-GlcNAcylation is likely a generalized cellular status effector as it responds to various cellular signals and conditions, such as ER stress, apoptosis, and infection. In this review, we summarize the metabolic regulation of protein O-GlcNAcylation through nutrient availability, HBP enzymes, and O-GlcNAc processing enzymes. We discuss the emerging roles of circadian clocks in regulating daily O-GlcNAcylation rhythm. Finally, we provide an overview of other cellular signals or conditions that impact O-GlcNAcylation. Many of these cellular pathways are themselves regulated by the clock and/or metabolism. Our review highlights the importance of maintaining optimal O-GlcNAc rhythm by restricting eating activity to the active period under physiological conditions and provides insights into potential therapeutic targets of O-GlcNAc homeostasis under pathological conditions.

Across internally fertilising species, males transfer ejaculate proteins that trigger wide-ranging changes in female behaviour and physiology. Much theory has been developed to explore the drivers of ejaculate protein evolution. The accelerating availability of high-quality genomes now allows us to test how these proteins are evolving at fine taxonomic scales. Here, we use genomes from 264 species to chart the evolutionary history of Sex Peptide (SP), a potent regulator of female post-mating responses in Drosophila melanogaster. We infer that SP first evolved in the Drosophilinae subfamily and has since followed markedly different evolutionary trajectories in different lineages. Outside of the Sophophora-Lordiphosa, SP exists largely as a single-copy gene with independent losses in several lineages. Within the Sophophora-Lordiphosa, the SP gene family has repeatedly and independently expanded. Up to seven copies, collectively displaying extensive sequence variation, are present in some species. Despite these changes, SP expression remains restricted to the male reproductive tract. Alongside, we document considerable interspecific variation in the presence and morphology of seminal microcarriers that, despite the critical role SP plays in microcarrier assembly in D. melanogaster, appears to be independent of changes in the presence/absence or sequence of SP. We end by providing evidence that SP's evolution is decoupled from that of its receptor, Sex Peptide Receptor, in which we detect no evidence of correlated diversifying selection. Collectively, our work describes the divergent evolutionary trajectories that a novel gene has taken following its origin and finds a surprisingly weak coevolutionary signal between a supposedly sexually antagonistic protein and its receptor.

Hypoxia not only plays a critical role in multiple disease conditions; it also influences the growth and development of cells, tissues and organs. To identify novel hypoxia-related mechanisms involved in cell and tissue growth, studying a precise hypoxia-sensitive time window can be an effective approach. Drosophila melanogaster has been a useful model organism for studying a variety of conditions, and we focused in this study on the life cycle stages of Drosophila to investigate their hypoxia sensitivity. When normoxia-grown flies were treated with 4% O2 at the pupa stage for 3, 2 and 1 day/s, the eclosion rates were 6.1%, 66.7% and 96.4%, respectively, and, when 4% O2 was kept for the whole pupa stage, this regimen was lethal. Surprisingly, when our hypoxia-adapted flies who normally live in 4% O2 were treated with 4% O2 at the pupa stage, no fly eclosed. Within the pupa stage, the pupae at 2 and 3 days after pupae formation (APF), when treated for 2 days, demonstrated 12.5 ± 8.5% and 23.6 ± 1.6% eclosion, respectively, but this was completely lethal when treated for 3 days. We conclude that pupae, at 2 days APF and for a duration of a minimum of 2 days, were the most sensitive to hypoxia. Our data from our hypoxia-adapted flies clearly indicate that epigenetic factors play a critical role in pupa-stage hypoxia sensitivity.

The ability to independently control gene expression in two different tissues in the same animal is emerging as a major need, especially in the context of inter-organ communication studies. This type of study is made possible by technologies combining the GAL4/UAS and a second binary expression system such as the LexA system or QF system. Here, we describe a resource of reagents that facilitate combined use of the GAL4/UAS and a second binary system in various Drosophila tissues. Focusing on genes with well-characterized GAL4 expression patterns, we generated a set of more than 40 LexA-GAD and QF2 insertions by CRISPR knock-in and verified their tissue specificity in larvae. We also built constructs that encode QF2 and LexA-GAD transcription factors in a single vector. Following successful integration of this construct into the fly genome, FLP/FRT recombination is used to isolate fly lines that express only QF2 or LexA-GAD. Finally, using new compatible shRNA vectors, we evaluated both LexA and QF systems for in vivo gene knockdown and are generating a library of such RNAi fly lines as a community resource. Together, these LexA and QF system vectors and fly lines will provide a new set of tools for researchers who need to activate or repress two different genes in an orthogonal manner in the same animal.

Metabolism participates in the control of stem cell function and subsequent maintenance of tissue homeostasis. How this is achieved in the context of adult stem cell niches in coordination with other local and intrinsic signaling cues is not completely understood. The Target of Rapamycin (TOR) pathway is a master regulator of metabolism and plays essential roles in stem cell maintenance and differentiation. In the Drosophila male germline, mTORC1 is active in germline stem cells (GSCs) and early germ cells. Targeted RNAi-mediated downregulation of mTor in early germ cells causes a block and/or a delay in differentiation, resulting in an accumulation of germ cells with GSC-like features. These early germ cells also contain unusually large and dysfunctional autolysosomes. In addition, downregulation of mTor in adult male GSCs and early germ cells causes non-autonomous activation of mTORC1 in neighboring cyst cells, which correlates with a disruption in the coordination of germline and somatic differentiation. Our study identifies a previously uncharacterized role of the TOR pathway in regulating male germline differentiation.

The role of mitochondria in immunity is increasingly recognized, but it is unclear how variation in mitochondrial DNA (mtDNA) contributes to variable infection outcomes. To quantify the effect of mtDNA variation on humoral and cell-mediated innate immune responses, we utilized a panel of fruit fly Drosophila melanogaster cytoplasmic hybrids (cybrids), where unique mtDNAs (mitotypes) were introgressed into a controlled isogenic nuclear background. We observed substantial heterogeneity in infection outcomes within the cybrid panel upon bacterial, viral and parasitoid infections, driven by the mitotype. One of the mitotypes, mtKSA2 protected against bacterial, parasitoid, and to a lesser extent, viral infections. Enhanced survival was not a result of improved bacterial clearance, suggesting mtKSA2 confers increased disease tolerance. Transcriptome sequencing showed that the mtKSA2 mitotype had an upregulation of genes related to mitochondrial respiration and phagocytosis in uninfected flies. Upon infection, mtKSA2 flies exhibited infection type and duration specific transcriptomic changes. Furthermore, uninfected mtKSA2 larvae showed immune activation of hemocytes (immune cells), increased hemocyte numbers and ROS production, and enhanced encapsulation response against parasitoid wasp eggs and larvae. Our results show that mtDNA variation acts as an immunomodulatory factor in both humoral and cell-mediated innate immunity and that specific mitotypes can provide broad protection against infections. Author summary: The strength of immune response and the disease symptoms vary among individuals even when exposed to the same pathogen. Much of this variation is due to the genes directly involved in adaptive and innate immune pathways. In addition, mitochondria are emerging as one of the factors modulating immune responses. Mitochondria are cellular organelles with their own genome (mtDNA) involved in many important processes, including producing ATP, the energy currency of the cells. mtDNA mutations leading to mitochondrial dysfunction are often considered harmful upon exposure to pathogens. Here, we used a fruit fly model where unique mtDNA variants are placed in a controlled nuclear genomic background to find out how mtDNA shapes infection outcomes upon bacterial, viral and parasitoid infections. We found that mtDNA variation alters the efficiency of immune response and describe a mtDNA variant that confers protection against variety of pathogens. This protection was at least partially caused by enhanced cell-mediated innate immunity, including higher numbers of immune cells prior to and during infection. [ABSTRACT FROM AUTHOR]

AbstractThe study of olfaction in Drosophila melanogaster has greatly benefited from genetic reagents such as olfactory receptor mutant lines and GAL4 reporter lines. The CRISPR/Cas9 gene-editing system has been increasingly used to create null receptor mutants or replace coding regions with GAL4 reporters. To further expand this toolkit for manipulating fly olfactory receptor neurons (ORNs), we generated null alleles for 11 different olfactory receptors by using CRISPR/Cas9 to knock in LexA drivers, including multiple lines for receptors which have thus far lacked knock-in mutants. The targeted neuronal types represent a broad range of antennal ORNs from all four morphological sensillum classes. Additionally, we confirmed their loss-of-function phenotypes, assessed receptor haploinsufficiency, and evaluated the specificity of the LexA knock-in drivers. These receptor mutant lines have been deposited at the Bloomington Drosophila Stock Center for use by the broader scientific community. [ABSTRACT FROM AUTHOR]

Glia is pivotal in regulating neuronal stem cell proliferation, functioning, and nervous system homeostasis, significantly influencing neuronal health and disorders. Dysfunction in glial activity is a key factor in the development and progression of brain pathology. However, a deeper understanding of the intricate nature of glial cells and their diverse role in neurological disorders is still required. To this end, we conducted data mining to retrieve literature from PubMed and Google Scholar using the keywords: glia, Drosophila, neurodegeneration, and mammals. The retrieved literature was manually screened and used to comprehensively understand and present the different glial types in Drosophila, i.e., perineurial, subperineurial, cortex, astrocyte-like and ensheathing glia, their relevance with mammalian counterparts, mainly microglia and astrocytes, and their potential to reveal complex neuron-glial molecular networks in managing neurodegenerative processes. [ABSTRACT FROM AUTHOR]

Introduction: Exposure to blue-enriched light from electronic devices is an emergent disruptor of human sleep, especially at particular times of day. Further dissection of this phenomenon necessitates modeling in a tractable model organism. Methods: Thus, we investigated the effects of light color on sleep in Drosophila melanogaster. We measured sleep in red-eyed Canton-S (CS) and white-eyed w 1118 flies in baseline 12:12 light/dark conditions and experimental conditions with light-color (blue, red, or green) exposure for all 12 h of daylight or 3 h in the morning or evening. Results: Blue light reduced daytime and nighttime sleep in CS but not in w 1118, potentially indicating a role for the compound eye in blue light's effects on fruit fly sleep. Red light, especially in the evening, reduced sleep during exposure in both strains. Green light had minimal effects on sleep in CS flies, but evening exposure reduced sleep in w 1118 flies, mimicking red light's effects. Discussion: In conclusion, light's effects on sleep in D. melanogaster are dependent on wavelength and time-of-day. Future studies will aim to dissect these mechanisms genetically. [ABSTRACT FROM AUTHOR]

Intorduction: Pathogens drive the evolution of host defence strategies, with both innate and adaptive immune systems playing key roles. Priming enhances the innate immune system's readiness by functionally reprogramming immune cells after initial exposure to stimuli, like β-glucans. In this sense, Drosophila melanogaster is a valuable model to evaluate the role of innate immunity to control infections. Objectives: In this study we aimed to set light on the immune priming effect of oral treatment with heat-killed M. manresensis and two different heat-killed C. albicans isolates upon systemic infection by C. albicans in the D. melanogaster model. Methods: A clinical and a control ATCC 90028 Candida albicans strain were used. Flies were primed through oral administration of heat-killed C. albicans (hkCa), both clinical and control, and hk- Mycolicibacterium manresensis. After priming, flies were systemically infected with both C. albicans isolates. Host survival, pathogen load, and immune response in response to treatment and infection were evaluated. Results: Both treatments showed a significant capacity to enhance the expression of antimicrobial peptides, in particular Diptericin, and Drosomycin in males. This response had a marked sexual dimorphism due to the difference in Upd3, Nox, and Duox expression. Surprisingly, even when priming was able to avoid the growth of both C. albicans strains, survival was not improved in the case of the clinical isolate, causing an unexpected mortality rate in hours, regardless of the host's sex. Gene expression analysis 24 hours post-infection showed an exacerbated increase in Diptericin, Drosomycin and Upd3 expression upon infection with the clinical strain. Conclusion: Data herein suggests the presence of a strain-specific component in C. albicans as the booster of a "stormy" innate immune response, which must be further investigated, and position D. melanogaster as a useful model for evaluating virulent factors related to the modulation of the innate immunity. [ABSTRACT FROM AUTHOR]

Here, we demonstrate that single strand annealing (SSA) can be co-opted for the precise autocatalytic excision of a drive element. We have termed this technology Repeat Mediated Excision of a Drive Element (ReMEDE). By engineering direct repeats flanking the drive allele and inducing a double-strand DNA break (DSB) at a second endonuclease target site within the allele, we increased the utilization of SSA repair. ReMEDE was incorporated into the mutagenic chain reaction (MCR) gene drive targeting the yellow gene of Drosophila melanogaster, successfully replacing drive alleles with wild-type alleles. Sequencing across the Cas9 target site confirmed transgene excision by SSA after pair-mated outcrosses with yReMEDE females, revealing ~4% inheritance of an engineered silent TcG marker sequence. However, phenotypically wild-type flies with alleles of indeterminate biogenesis also were observed, retaining the TGG sequence (~16%) or harboring a silent gGG mutation (~0.5%) at the PAM site. Additionally, ~14% of alleles in the F2 flies were intact or uncut paternally inherited alleles, indicating limited maternal deposition of Cas9 RNP. Although ReMEDE requires further research and development, the technology has some promising features as a gene drive mitigation strategy, notably its potential to restore wild-type populations without additional transgenic releases or large-scale environmental modifications. Author summary: CRISPR/Cas9-based autonomous homing gene drives have the potential to drastically reduce or eliminate vector-borne diseases, agricultural pests, and invasive species. However, their use raises significant regulatory, ethical, environmental, and sociopolitical concerns, particularly regarding unintended consequences. Responsible application of this powerful technology necessitates the development of control measures to halt or reverse any undesired outcomes. Several mitigation strategies have been proposed and, in some cases, demonstrated in laboratory settings, but their effectiveness in addressing concerns surrounding the use of gene drives in nature still remains uncertain. Therefore, ongoing investigation and consideration of additional control strategies is prudent. This manuscript describes proof-of-concept studies for a novel gene drive mitigation strategy, which we have termed Repeat Mediated Excision of a Drive Element (ReMEDE). While further research and development is required prior to any possible application of this strategy, the ReMEDE concept offers a theoretical potential to restore transgene-free populations with wild-type phenotypes after a well-defined period of efficient gene drive. [ABSTRACT FROM AUTHOR]

Background: Nilaparvata lugens is one of the most destructive pests of rice. RNAi-based N. lugens control offers one alternative strategy to traditional chemical insecticides. However, selection of potential target for RNAi against N. lugens remains a major challenge. Only two target genes for nuclear transgenic N. lugens-resistant plants have been screened. Importantly, only one or few potential target genes against N. lugens were screened every time by knowledge of essential genes from model organisms in previous study. Results: Here, in silico genome-wide selection of potential target genes against N. lugens through homology comparison was performed. Through genome synteny comparisons, about 3.5% of Drosophila melanogaster genome was found to have conserved genomic synteny with N. lugens genome. By using N. lugens proteins to search D. melanogaster homologs defining lethal or sterile phenotype, 358 N. lugens genes were first screened as putative target genes. Transgenic rice lines expressing dsRNA of randomly selected gene (NlRan or NlSRP54) from 358 putative target genes enhanced resistance to N. lugens. After expression check and safety check, 115 N. lugens genes were screened as potential target candidates. Conclusion: The combined efforts in this study firstly provide one in silico genome-wide homology-based screening approach for RNAi-based target genes against N. lugens, which not only offer one new opportunity to batch select potential target candidates in pests of interest, but also will facilitate the selection of RNAi target in many pest species by providing more than one hundred potential target candidates. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are post-transcriptional, non-coding regulatory RNAs that function coordinately with transcription factors (TFs) in gene regulatory networks. TFs and their targets are often co-regulated by miRNAs, forming composite feedforward circuits (cFFCs) with varying degrees of redundancy, primarily mediated by miRNAs. However, the maintenance of miRNA-mediated regulatory redundancy and its impact on gene expression evolution remain elusive. By integrating ChIP-seq data from ENCODE and miRNA targeting from TargetScanFly, we quantified miRNA-mediated cFFC redundancy in Drosophila melanogaster embryos and larvae, revealing more than three quarters of miRNA targets are involved in redundant cFFCs. Higher cFFC redundancy, where more miRNAs target the same gene within a cFFC, is correlated with stronger purifying selection, reduced expression divergence between species, and increased expression stability under heat shock stress. Redundant cFFCs primarily regulate older or broadly expressed young genes. These findings highlight the role of miRNA-mediated cFFC redundancy in enhancing gene expression robustness through natural selection. Network analysis reveals miRNAs mediate high redundancy of composite feedforward circuits (cFFCs) in Drosophila, correlating with strong purifying selection, reduced interspecies expression divergence, and increased stability under stress. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD), a form of neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ), hyperphosphorylated Tau, and neuroinflammation. The increasing population affected by AD urges for the development of effective treatments. The correlation between AD and gut microbiome remains underexplored, potentially providing a better understanding of the disease. Salvianolic acid A (Sal A) and salvianolic acid B (Sal B) are the active components extracted from Salvia miltiorrhiza (Danshen), and their antioxidant, anti-inflammation and Aβ inhibition activities were shown previously. In this study, these compounds were used to investigate their effects on Aβ toxicity, using Drosophila melanogaster expressing human Aβ42 as the model organism, by examining their lifespan and changes in gut bacterial communities. The study used two batches of flies, reared on food with or without methylparaben (MP) supplementation to evaluate the influence of MP on this animal model during pharmacological studies. MP is a common antimicrobial agent used in flies' food. The treatment of Sal A prolonged the lifespan of Aβ-expressing flies reared on MP-supplemented food significantly (P < 0.001), but not those without MP. The lifespan of Sal B-treated flies did not show a significant difference compared to untreated flies for both groups reared on food with and without MP. Sal A-treated flies in the presence of MP exhibited a lower abundance of Corynebacterium and Enterococcus than the untreated flies, while Lactiplantibacillus was the most dominant taxa. Urea cycle was predicted to be predominant in this group compared to the untreated group. The control group, Aβ-expressing flies treated with Sal A and Sal B on MP-supplemented food had improved lifespan compared to their respective groups reared on food without MP, while untreated Aβ-expressing flies was the exception. The gut microbiota composition of flies reared on MP-supplemented food was also significantly different from those without MP (P < 0.001). [ABSTRACT FROM AUTHOR]

The Snail superfamily of transcription factors plays a crucial role in metazoan development; one of the most important vertebrate members of this family is Snai1 which is orthologous to the Drosophila melanogaster esg gene. This review offers a comprehensive examination of the roles of the esg gene in Drosophila development, covering its expression pattern and downstream targets, and draws parallels between the vertebrate Snai1 family proteins on controlling the epithelial‐to‐mesenchymal transition and esg. This gene regulates stemness, ploidy, and pluripontency. esg is expressed in various tissues during development, including the gut, imaginal discs, and neuroblasts. The functions of the esg include the suppression of differentiation in intestinal stem cells and the preservation of diploidy in imaginal cells. In the nervous system development, esg expression also inhibits neuroblast differentiation, thus regulating the number of neurons and the moment in development of neuronal differentiation. Loss of esg function results in diverse developmental defects, including defects in intestinal stem cell maintenance and differentiation, and alters imaginal disc and nervous system development. Expression levels of esg also play a role in regulating longevity and metabolism in adult stages. This review provides an overview of the current understanding of esg's developmental role, emphasizing cellular and tissue effects that arise from its loss of function. The insights gained may contribute to a better understanding of evolutionary conserved developmental mechanisms and certain metabolic diseases. [ABSTRACT FROM AUTHOR]

About two-thirds of the genes in the Drosophila melanogaster genome are also involved in its eye development, making the Drosophila eye an ideal system for genetic studies. We previously developed Flynotyper, a software that uses image processing operations to identify and quantify the degree of roughness by measuring disorderliness of ommatidial arrangement in the fly eye. This software has enabled researchers to quantify morphological defects of thousands of eye images caused by genetic perturbations. Here, we present Flynotyper 2.0, a software that has an updated computer vision library, improved performance, and a streamlined pipeline for high-throughput analysis of multiple eye images. We also tested several batches of Drosophila eye images to ensure robustness and reproducibility of the updated Flynotyper 2.0 software. [ABSTRACT FROM AUTHOR]

Drosophila melanogaster usage has provided substantial insights into the pathogenesis of several nucleotide repeat expansion diseases (NREDs), a group of genetic diseases characterized by the abnormal expansion of DNA repeats. Leveraging the genetic simplicity and manipulability of Drosophila, researchers have successfully modeled close to 15 NREDs such as Huntington's disease (HD), several spinocerebellar ataxias (SCA), and myotonic dystrophies type 1 and 2 (DM1/DM2). These models have been instrumental in characterizing the principal associated molecular mechanisms: protein aggregation, RNA toxicity, and protein function loss, thus recapitulating key features of human disease. Used in chemical and genetic screenings, they also enable us to identify promising small molecules and genetic modifiers that mitigate the toxic effects of expanded repeats. This review summarizes the close to 150 studies performed in this area during the last seven years. The relevant highlights are the achievement of the first fly-based models for some NREDs, the incorporation of new technologies such as CRISPR for developing or evaluating transgenic flies containing repeat expanded motifs, and the evaluation of less understood toxic mechanisms in NREDs such as RAN translation. Overall, Drosophila melanogaster remains a powerful platform for research in NREDs. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are key effector molecules in innate immunity, both systemically and locally. AMPs also play important roles in brain functions such as memory and sleep in the absence of infection. The expression of many AMPs is increased during aging, neurodegeneration, and brain injuries. Overactivation of certain AMPs contributes to neuronal cell death in several neurodegenerative disease models. Antimicrobial peptides (AMPs), a collection of small proteins with important roles in classical innate immunity, have been extensively studied in multiple organisms, particularly in Drosophila melanogaster. Advances in CRISPR/Cas9 genome editing have allowed individual AMP functions to be dissected, revealing specific and selective roles in host defense. Recent findings have also revealed many unexpected contributions of endogenous AMPs to neuronal functions and neurodegenerative diseases, and have shed light on the intersections between innate immunity and neurobiology. We explore the intricate relationships between AMPs and sleep regulation, memory formation, as well as traumatic brain injury and several neurodegenerative diseases such as Alzheimer's disease (AD), frontotemporal dementia (FTD), and Parkinson's disease (PD). Understanding the diverse functions of AMPs opens new avenues for neuroinflammation and neurodegenerative disease research and potential therapeutic development. [ABSTRACT FROM AUTHOR]

We have analyzed the organization of the microtubule system in photoreceptor cells and pigment cells within the adult Drosophila compound eye. Immunofluorescence localization of tubulin and of Short stop, a spectraplakin that has been reported to be involved in the anchorage of microtubule minus ends at the membrane, suggests the presence of non-centrosomal microtubule-organizing centers at the distal tip of the visual cells. Ultrastructural analyses confirm that microtubules emanate from membrane-associated plaques at the site of contact with cone cells and that all microtubules are aligned in distal–proximal direction within the photoreceptor cells. Determination of microtubule polarities demonstrated that about 95% of the microtubules in photoreceptor cells are oriented with their plus end in the direction of the synapse. Pigment cells in the eye contain only microtubules aligned in distal–proximal direction, with their plus end pointing towards the retinal floor. There, two populations of microtubules can be distinguished, single microtubules and bundled microtubules, the latter associated with actin filaments. Whereas microtubules in both photoreceptor cells and pigment cells are acetylated and mono/bi-glutamylated on α-tubulin, bundled microtubules in pigment cells are apparently also mono/bi-glutamylated on β-tubulin, providing the possibility of binding different microtubule-associated proteins. [ABSTRACT FROM AUTHOR]

Living organisms, which are constantly exposed to cyclical variations in their environment, need a high degree of plasticity in their visual system to respond to daily and seasonal fluctuations in lighting conditions. In Drosophila melanogaster, the visual system is a complex tissue comprising different photoreception structures that exhibit daily rhythms in gene expression, cell morphology, and synaptic plasticity, regulated by both the central and peripheral clocks. In this review, we briefly summarize the structure of the circadian clock and the visual system in Drosophila and comprehensively describe circadian oscillations in visual structures, from molecules to behaviors, which are fundamental for the fine‐tuning of visual sensitivity. We also compare some features of the rhythmicity in the visual system with that of the central pacemaker and hypothesize about the differences in the regulatory signals and mechanisms that control these two clocks. [ABSTRACT FROM AUTHOR]

In biomedical research, the fruit fly (Drosophila melanogaster) is among the most effective and flexible model organisms. Through the use of the Drosophila model, molecular mechanisms of human diseases can be investigated and candidate pharmaceuticals can be screened. White rot fungus Inonotus obliquus is a member of the family Hymenochaetaceae. Due to its multifaceted pharmacological effects, this fungus has been the subject of scientific investigation. Nevertheless, the precise mechanisms by which Inonotus obliquus treats diseases remain unclear. In this study, we prepared an aqueous extract derived from Inonotus obliquus and demonstrated that it effectively prevented the negative impacts of inflammatory agents on flies, including overproliferation and overdifferentiation of intestinal progenitor cells and decreased survival rate. Furthermore, elevated reactive oxygen species levels and cell death were alleviated by Inonotus obliquus aqueous extract, suggesting that this extract inhibited intestinal inflammation. Additionally, Inonotus obliquus aqueous extract had an impact on the insulin pathway, as it alleviated growth defects in flies that were fed a high-sugar diet and in chico mutants. In addition, we determined the composition of Inonotus obliquus aqueous extract and conducted a network pharmacology analysis in order to identify prospective key compounds and targets. In brief, Inonotus obliquus aqueous extract exhibited considerable potential as a therapeutic intervention for human diseases. Our research has established a foundational framework that supports the potential clinical implementation of Inonotus obliquus. [ABSTRACT FROM AUTHOR]

Switching from mitotic spermatogonia to meiotic spermatocytes is critical to producing haploid sperms during male germ cell differentiation. However, the underlying mechanisms of this switch remain largely unexplored. In Drosophila melanogaster, the gene RpL38 encodes the ribosomal protein L38, one component of the 60S subunit of ribosomes. We found that its depletion in spermatogonia severely diminished the production of mature sperms and thus led to the infertility of male flies. By examining the germ cell differentiation in testes, we found that RpL38-knockdown blocked the transition from spermatogonia to spermatocytes and accumulated spermatogonia in the testis. To understand the intrinsic reason for this blockage, we conducted proteomic analysis for these spermatogonia populations. Differing from the control spermatogonia, the accumulated spermatogonia in RpL38-knockdown testes already expressed many spermatocyte markers but lacked many meiosis-related proteins, suggesting that spermatogonia need to prepare some important proteins for meiosis to complete their switch into spermatocytes. Mechanistically, we found that the expression of bag of marbles (bam), a crucial determinant in the transition from spermatogonia to spermatocytes, was inhibited at both the mRNA and protein levels upon RpL38 depletion. We also confirmed that the bam loss phenocopied RpL38 RNAi in the testis phenotype and transcriptomic profiling. Strikingly, overexpressing bam was able to fully rescue the testis abnormality and infertility of RpL38-knockdown flies, indicating that bam is the key effector downstream of RpL38 to regulate spermatogonia differentiation. Overall, our data suggested that germ cells start to prepare meiosis-related proteins as early as the spermatogonial stage, and RpL38 in spermatogonia is required to regulate their transition toward spermatocytes in a bam-dependent manner, providing new knowledge for our understanding of the transition process from spermatogonia to spermatocytes in Drosophila spermatogenesis. [ABSTRACT FROM AUTHOR]

Maternal nutrition, including the availability of micronutrients such as zinc, influences the health of the offspring. Using Drosophila melanogaster, we studied the impact of zinc deficiency on development and reproduction, as well as the effects of maternal zinc status on the offspring's expression of zinc transporters across F1 to F3 generations. Zinc deficiency was induced by adding N,N,N′,N′-Tetrakis (2-pyridylmethyl)-ethylenediamine (TPEN) to the diet on which the eggs representing the F0 generation flies were laid. Then, virgin F0 females were mated with control males to produce F1, and subsequently thereafter to generate F2 and F3. Offspring from F1 to F3 were analyzed for body zinc status and zinc transporter mRNA levels. We found that zinc deficiency significantly (p < 0.05) impaired the development of flies, as evidenced by a reduced eclosion rate of zinc-deficient flies. Similarly, zinc deficiency significantly (p < 0.05) reduced the egg-laying rate in F0 flies, highlighting its impact on reproductive functions. Also, zinc levels were consistently lower in the F0 and persisted in subsequent generations for both male and female offspring, indicating transgenerational alterations in zinc status. Furthermore, gene expression analysis revealed significant (p < 0.05) variations in the mRNA levels of dZip42C.1, dZnT63C, dZip71B, and dZnT35C genes across different generations and between male and female offspring. These findings indicate gender-specific dynamics of gene expression in response to zinc deficiency, suggesting potential regulatory mechanisms involved in maintaining zinc homeostasis. Our study emphasizes the detrimental effects of zinc deficiency on development and reproduction in Drosophila and highlights potential implications for offspring and human health. [ABSTRACT FROM AUTHOR]

Consumption of a high-fat diet is accompanied by the risks of obesity and early onset of age-associated complications for which dietary interventions are imperative to combat. α-lipoic acid has been shown to hinder diet-induced obesity and induce lifespan-extending efficacy in model organisms. In this study, α-lipoic acid was investigated for its efficacy in improving lifespan and stress resistance in the Canton-S strain of Drosophila melanogaster fed with a high-fat diet. Furthermore, as mating status significantly impacts survival in fruit flies, flies were reared in two experimental groups—group one, in which males and females were bred together, and group two, in which males and females were bred separately. In group one, α-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 2–2.5 mM, respectively. In group two, α-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 1–2.5 mM, respectively. Improved climbing efficiency was observed with α-lipoic acid at the dose range of 1.5–2.5 mM in flies of group one and 1–2.5 mM in flies of group two, respectively. Administration of α-lipoic acid improved resistance to oxidative stress in only female flies of group one at 2.5 mM, whereas in group two, both male and female flies exhibited enhanced resistance to oxidative stress with α-lipoic acid at a dose range of 2–2.5 mM, respectively. Male and female flies of only group one showed improved resistance to heat shock stress with α-lipoic acid at a dose range of 2–2.5 mM. Only female flies of group two exhibited a slight improvement in recovery time following cold shock with α-lipoic acid only at 2.5 mM. No significant change in resistance to starvation stress was observed with any dose of α-lipoic acid in either group of flies. To summarize, data from this study suggested a probable dose and gender-dependent efficacy of α-lipoic acid in flies fed with a high-fat diet, which was significantly influenced by the mating status of flies due to varied rearing conditions. [ABSTRACT FROM AUTHOR]

Aging entails the progressive decline in the body's self-regulation and functionality over time. Notably, obesity and aging exhibit parallel phenotypes, with obesity further accelerating the aging process across multiple dimensions and diminishing lifespan. In this study, we explored the impact of trans fatty acid (TFA) consumption on the overall health and lifespan of male Drosophila melanogaster under an isocaloric high-sugar and high-fat diet. Our results indicate that TFA intake results in a shortened lifespan, elevated body weight, and increased triglyceride levels in flies fed a high-sugar and high-fat diet with equivalent caloric intake. Additionally, TFA exposure induces oxidative stress, locomotor deficits, and damage to the intestinal barrier in flies. Collectively, chronic TFA consumption expedites the aging process and reduces the lifespan of male Drosophila melanogaster. These results contribute supplementary evidence regarding the adverse health effects associated with TFAs. Trans fatty acid intake results in a shortened lifespan, elevated body weight, and increased triglyceride levels in male Drosophila melanogaster fed a high-sugar and high-fat diet with equivalent caloric intake. Additionally, Trans fatty acid exposure induces oxidative stress, locomotor deficits, and damage to the intestinal barrier in flies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Spinosyns are a group of naturally occurring and semi‐synthetic insecticides with widespread utility in agriculture, including organic production systems. One example is spinetoram (Delegate), which is the only registered insecticide in New York State (for control of Drosophila melanogaster in vineyards) to which vinegar flies have not yet evolved high levels of resistance. However, low levels of resistance have been found in vineyard populations of D. melanogaster, and a highly resistant strain was obtained after only five selections (in the laboratory). We identified the nAChR α6 mutation (G275A) responsible for the resistance and developed a rapid, high‐throughput assay for resistance. RESULTS: Surveys of collections made in 2023 show low levels of the resistance allele in four populations. A correlation was observed between vineyard use of spinetoram and frequency of the resistance allele, but not between county‐wide use of spinosyns and frequency of the resistance allele. CONCLUSIONS: One of the sites we monitored was previously surveyed in 2019 and the frequency of the resistance allele detected in 2023 had increased. Implications of these findings to resistance management of D. melanogaster are discussed. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study investigated the behavioral responses and toxicity of three basic amines: 1‐methylpiperazine, 1‐methylpyrrolidine, and triethylamine (TEA), compounds suggested previously to be anosmic in vapor exposures to caged mosquitoes. RESULTS: These compounds showed repellency of Aedes aegypti mosquitoes, followed by flightlessness, knockdown, and paralysis, all increasing with exposure time and dosage. Electrophysiological experiments showed a blocking effect on nerve discharge of the Drosophila melanogaster larval central nervous system (CNS) with little evidence of hyperexcitation. Blockage of voltage‐gated (Kv2) potassium channel currents under patch clamp occurred at similar concentrations. Involvement of K+ channels in the action of basic amines was supported by behavior and CNS recordings of a Shaker Kv1 mutant exposed to TEA, where instead of blockage, a hyperexcitation of nerve firing was observed. Experiments on cockroach leg mechanoreceptors demonstrated neuronal excitation and on mosquito antennae strong electroantennogram (EAG) signals with an augmentation of blank air responses after a single puff of basic amine. CONCLUSIONS: The neurophysiological effects of basic amines are consistent with K+ channel block, whereas the antennal EAG response was not obviously associated with anosmia. The low‐dose effects of basic amines appear to be repellency and bradykinesia. Overall, the findings provide key insights into the mechanisms underlying the biological activity of basic amines. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Tobacco, a extensively consumed plant recognized for its adverse health effects in humans, comprises various toxic compounds. Previous researches have solely delved into the impact of nicotine exposure on the reproductive and developmental aspects of fruit flies. Consequently, our investigation seeks to broaden the comprehension of the detrimental impacts encompassing all constituents of tobacco extract on the lifespan of fruit flies. Varied concentrations of tobacco extract (0.02, 0.04, 0.06, 0.08, and 0.1 g) were employed to establish a spectrum of exposure levels and the data included the number of fruit flies at each developmental stage in the new generation and the lifespan in each concentration group over the time. Our findings demonstrate a decline in population size within the first and second filial generations when transitioning from a normal condition to a high concentration of tobacco. Furthermore, our results reveal an inverse relationship between pupa size and tobacco concentration, resulting in smaller fruit flies when exposed to higher concentrations of tobacco extract. This suggests a detrimental impact of tobacco toxins on the embryonic development and overall well-being of fruit flies. The implications of our study extend to a broader understanding of potential risks associated with tobacco exposure in various organisms, including humans. [ABSTRACT FROM AUTHOR]

Phosducin-like proteins (PhLP) are thioredoxin domain-containing proteins that are highly conserved across unicellular and multicellular organisms. PhLP family proteins are hypothesized to function as co-chaperones in the folding of cytoskeletal proteins. Here, we present the initial molecular, biochemical, and functional characterization of CG4511 as Drosophila melanogaster PhLP3. We cloned the gene into a bacterial expression vector and produced enzymatically active recombinant PhLP3, which showed similar kinetics to previously characterized orthologues. A fly strain homozygous for a P-element insertion in the 5' UTR of the PhLP3 gene exhibited significant downregulation of PhLP3 expression. We found these male flies to be sterile. Microscopic analysis revealed altered testes morphology and impairment of spermiogenesis, leading to a lack of mature sperm. Among the most significant observations was the lack of actin cones during sperm maturation. Excision of the P-element insertion in PhLP3 restored male fertility, spermiogenesis, and seminal vesicle size. Given the high level of conservation of PhLP3, our data suggests PhLP3 may be an important regulator of sperm development across species. [ABSTRACT FROM AUTHOR]

Drosophila melanogaster exhibits multiple highly sophisticated temperature-sensing systems, enabling its effective response and navigation to temperature changes. Previous research has identified three dorsal organ cool cells (DOCCs) in fly larvae, consisting of two A-type and one B-type cell with distinct calcium dynamics. When subjected to hypertonic conditions, calcium imaging shows that A-type DOCCs maintain their responses to cool temperatures. In contrast, a subset of B-type DOCCs does not exhibit detectable GCaMP baseline signals, and the remaining detectable B-type DOCCs exhibit reduced temperature responses. The activation of both A-type and B-type DOCCs depends on the same members of the ionotropic receptor (IR) family: IR21a, IR93a, and IR25a. A-type DOCCs exhibit a higher somal level of IR93a than B-type DOCCs. Overexpression of Ir93a restores B-type calcium responses to cool temperatures, but not the proportion of B-type cells with a detectable GCaMP baseline, in a hypertonic environment, suggesting a selective role of IR93a in maintaining the temperature responses under hypertonic conditions. Our findings identify a novel function of B-type DOCCs in integrating temperature and tonic stimuli. [ABSTRACT FROM AUTHOR]

AbstractThis study assessed the antioxidative and protective effects of peptide extracts from selected Euphorbia species on Aluminum Chloride (AlCl3)-induced toxicity in Drosophila melanogaster. Euphorbia humifusa (EHU), Euphorbia hirta (EHI), and Euphorbia graminae (EHG) were screened for bioactive peptides. The crude peptide extract and partially purified peptide fractions of all the plants were subjected to preliminary antioxidants activities through 2, 2-diphenyl-1-picrylhyhdrazyl (DPPH), and nitric oxide (NO) scavenging activities. The most active peptide fraction was subjected to biochemical studies using Drosophila melanogaster. Flies were treated with AlCl3 (100 mg/kg diet), peptide fraction (5 and 10 mg/kg diet), and cotreatment of AlCl3 and the fraction, respectively. After treatment, flies were homogenized for the determination of total thiol and Glutathione (non-protein thiol) content, catalase and Glutathione-S-transferase activities, and nitric oxide (nitrite/nitrate) and hydroperoxide levels. The antioxidant screening revealed that the peptide fraction from Euphorbia humifusa (PEHU) was the most significant compared to the control (ascorbic acid). The PEHU (5 and 10 mg/kg diet) maintained the redox status of the flies in the biochemical study. The PEHU significantly counteracted AlCl3-induced reduction in antioxidants (catalase, GST, GSH and Total thiol), increased nitric oxide levels, and acetylcholinesterase activity and prevented behavioral deficits flies. Hence, the peptide fraction of Euphorbia humifusa may shield against the life-threatening effects of free radicals associated with aluminum chloride toxicity. [ABSTRACT FROM AUTHOR]