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Tissue Barriers Apr 2017The role of Slit/Robo signaling has extended from initial axon repulsion in the developing nervous system to organ morphogenesis, cancer development and angiogenesis.... (Review)
Review
The role of Slit/Robo signaling has extended from initial axon repulsion in the developing nervous system to organ morphogenesis, cancer development and angiogenesis. Slit/Robo signaling regulates similar pathways within these processes. Slit/Robo ensures the homeostasis of the dynamic interaction between cell-cell and cell-matrix interactions. The dysregulation of Slit/Robo signaling damages the tissue barrier, resulting in developmental abnormalities or disease. Here, we summarize how Slit/Robo controls kidney morphogenesis and describe the dual roles of Slit/Robo signaling in the regulation of tumorigenesis and angiogenesis.
Topics: Animals; Cell Communication; Drosophila Proteins; Models, Biological; Nerve Tissue Proteins; Receptors, Immunologic; Signal Transduction; Roundabout Proteins
PubMed: 28598714
DOI: 10.1080/21688370.2017.1331155 -
Current Biology : CB Jan 2023Circadian clocks align various behaviors such as locomotor activity, sleep/wake, feeding, and mating to times of day that are most adaptive. How rhythmic information in...
Circadian clocks align various behaviors such as locomotor activity, sleep/wake, feeding, and mating to times of day that are most adaptive. How rhythmic information in pacemaker circuits is translated to neuronal outputs is not well understood. Here, we used brain-wide, 24-h in vivo calcium imaging in the Drosophila brain and searched for circadian rhythmic activity among identified clusters of dopaminergic (DA) and peptidergic neurosecretory (NS) neurons. Such rhythms were widespread and imposed by the PERIOD-dependent clock activity within the ∼150-cell circadian pacemaker network. The rhythms displayed either a morning (M), evening (E), or mid-day (MD) phase. Different subgroups of circadian pacemakers imposed neural activity rhythms onto different downstream non-clock neurons. Outputs from the canonical M and E pacemakers converged to regulate DA-PPM3 and DA-PAL neurons. E pacemakers regulate the evening-active DA-PPL1 neurons. In addition to these canonical M and E oscillators, we present evidence for a third dedicated phase occurring at mid-day: the l-LNv pacemakers present the MD activity peak, and they regulate the MD-active DA-PPM1/2 neurons and three distinct NS cell types. Thus, the Drosophila circadian pacemaker network is a polyphasic rhythm generator. It presents dedicated M, E, and MD phases that are functionally transduced as neuronal outputs to organize diverse daily activity patterns in downstream circuits.
Topics: Animals; Drosophila melanogaster; Motor Activity; Circadian Rhythm; Drosophila; Circadian Clocks; Drosophila Proteins; Dopaminergic Neurons
PubMed: 36610393
DOI: 10.1016/j.cub.2022.12.025 -
Genetics Oct 2021Embryonic patterning is critically dependent on zygotic genome activation (ZGA). In Drosophila melanogaster embryos, the pioneer factor Zelda directs ZGA, possibly in...
Embryonic patterning is critically dependent on zygotic genome activation (ZGA). In Drosophila melanogaster embryos, the pioneer factor Zelda directs ZGA, possibly in conjunction with other factors. Here, we have explored the novel involvement of Chromatin-Linked Adapter for MSL Proteins (CLAMP) during ZGA. CLAMP binds thousands of sites genome-wide throughout early embryogenesis. Interestingly, CLAMP relocates to target promoter sequences across the genome when ZGA is initiated. Although there is a considerable overlap between CLAMP and Zelda binding sites, the proteins display distinct temporal dynamics. To assess whether CLAMP occupancy affects gene expression, we analyzed transcriptomes of embryos zygotically compromised for either clamp or zelda and found that transcript levels of many zygotically activated genes are similarly affected. Importantly, compromising either clamp or zelda disrupted the expression of critical segmentation and sex determination genes bound by CLAMP (and Zelda). Furthermore, clamp knockdown embryos recapitulate other phenotypes observed in Zelda-depleted embryos, including nuclear division defects, centrosome aberrations, and a disorganized actomyosin network. Based on these data, we propose that CLAMP acts in concert with Zelda to regulate early zygotic transcription.
Topics: Animals; Binding Sites; DNA-Binding Proteins; Drosophila Proteins; Drosophila melanogaster; Gene Expression Regulation, Developmental; Nuclear Proteins; Protein Binding; Zygote
PubMed: 34849887
DOI: 10.1093/genetics/iyab107 -
Fly 2019The transgenic technology and fluorescent protein fusions are powerful tools to analyze protein expression patterns, subcellular localization and protein dynamics....
The transgenic technology and fluorescent protein fusions are powerful tools to analyze protein expression patterns, subcellular localization and protein dynamics. Recently, the transgenic technology has been improved by the highly efficient phiC31 site-specific integration system. Many new and improved fluorescent proteins with desirable advantages have been developed. However, the phiC31 system and the newly developed fluorescent proteins have not been systematically applied in transgenic vectors. Here, we have constructed a modular toolset of C-terminal fluorescent protein fusion vectors based on phiC31 site-specific integration system for the generation of transgenic lines. These cloning vectors contain a variety of fluorescent tags, including blue, cyan, green or red fluorescent proteins, photoactivatable or photoswitchable fluorescent proteins, fluorescent timers, photosensitizers and bimolecular fluorescence complementation tags. These vectors provide a range of transcriptional regulation options including UAST, UASP, UASC, LexAop, QUAS, Ubi, αTub67C and αTub84B promoters, and two screening marker options including and gene. The vectors have been tested and can produce fluorescent chimeric proteins that are functional.
Topics: Animals; Animals, Genetically Modified; Cloning, Molecular; Drosophila Proteins; Drosophila melanogaster; Fluorescent Antibody Technique; Gene Expression Regulation, Developmental; Genetic Vectors
PubMed: 30885036
DOI: 10.1080/19336934.2019.1595999 -
ENeuro Sep 2023Recent work in has uncovered several neighboring classes of sleep-regulatory neurons within the central complex. However, the logic of connectivity and network motifs...
Recent work in has uncovered several neighboring classes of sleep-regulatory neurons within the central complex. However, the logic of connectivity and network motifs remains limited by the incomplete examination of relevant cell types. Using a recent genetic-anatomic classification of ellipsoid body ring neurons, we conducted a thermogenetic screen in female flies to assess sleep/wake behavior and identified two wake-promoting drivers that label ER3d neurons and two sleep-promoting drivers that express in ER3m cells. We then used intersectional genetics to refine driver expression patterns. Activation of ER3d cells shortened sleep bouts, suggesting a key role in sleep maintenance. While sleep-promoting drivers from our mini-screen label overlapping ER3m neurons, intersectional strategies cannot rule out sleep regulatory roles for additional neurons in their expression patterns. Suppressing GABA synthesis in ER3m neurons prevents postinjury sleep, and GABAergic ER3d cells are required for thermogenetically induced wakefulness. Finally, we use an activity-dependent fluorescent reporter for putative synaptic contacts to embed these neurons within the known sleep-regulatory network. ER3m and ER3d neurons may receive connections from wake-active Helicon/ExR1 cells, and ER3m neurons likely inhibit ER3d neurons. Together, these data suggest a neural mechanism by which previously uncharacterized circuit elements stabilize sleep-wake states.
Topics: Animals; Female; Drosophila; Sleep; Neurons; Wakefulness; Drosophila melanogaster; Drosophila Proteins
PubMed: 37679041
DOI: 10.1523/ENEURO.0281-23.2023 -
Current Biology : CB Apr 2023Chronic sleep loss profoundly impacts metabolic health and shortens lifespan, but studies of the mechanisms involved have focused largely on acute sleep deprivation. To...
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.
Topics: Animals; Drosophila melanogaster; Drosophila Proteins; Sleep; Drosophila; Polyamines
PubMed: 36965479
DOI: 10.1016/j.cub.2023.03.008 -
Journal of Neurogenetics 2023Circadian rhythms and sleep homeostasis constitute the two-process model for daily sleep regulation. However, evidence for circadian control of sleep-wake cycles has...
Circadian rhythms and sleep homeostasis constitute the two-process model for daily sleep regulation. However, evidence for circadian control of sleep-wake cycles has been relatively short since clock-less animals often show sleep behaviors quantitatively comparable to wild-type. Here we examine sleep behaviors under different light-dark regimes and demonstrate that circadian clocks gate light-induced arousal. Genetic excitation of tyrosine decarboxylase 2 (TDC2)-expressing neurons suppressed sleep more evidently at night, causing nocturnal activity. The arousal effects were likely mediated in part by glutamate transmission from the octopaminergic neurons and substantially masked by light. Application of T12 cycles (6-h light: 6-h dark) further showed that the light-sensitive effects of TDC2 neurons depended on the time of the day. In particular, light-sensing via visual input pathway led to strong sleep suppression at subjective night, and such an effect disappeared in clock-less mutants. Transgenic mapping revealed that light-induced arousal and free-running behavioral rhythms require distinct groups of circadian pacemaker neurons. These results provide convincing evidence that circadian control of sleep is mediated by the dedicated clock neurons for light-induced arousal.
Topics: Animals; Drosophila; Sleep; Circadian Rhythm; Animals, Genetically Modified; Arousal; Drosophila Proteins; Drosophila melanogaster
PubMed: 36457164
DOI: 10.1080/01677063.2022.2151596 -
Frontiers in Immunology 2022Long noncoding RNAs (lncRNAs) are an emerging class of regulators that play crucial roles in regulating the strength and duration of innate immunity. However, little is...
Long noncoding RNAs (lncRNAs) are an emerging class of regulators that play crucial roles in regulating the strength and duration of innate immunity. However, little is known about the regulation of innate immunity-related lncRNAs. In this study, we first revealed that overexpression of could strengthen the expression of the Imd pathway antimicrobial peptide (AMP) genes () and () after infection, and vice versa. Secondly, RNA-seq analysis of -overexpressing flies post Gram-negative bacteria infection confirmed that positively regulated the immune deficiency (Imd) pathway. Mechanistically, we found that interacts and enhances the binding of NF-κB transcription factor Relish to and promoters, thereby facilitating and expression. Relish could also directly promote transcription by binding to its promoter. Finally, rescue experiments and dynamic expression profiling post-infection demonstrated the vital role of the Relish//AMP regulatory axis in enhancing Imd pathway and maintaining immune homeostasis. Our study elucidates novel mechanistic insights into the role of in activating Imd pathway and the complex regulatory interaction during the innate immune response of animals.
Topics: Animals; Antimicrobial Peptides; Drosophila; Drosophila Proteins; Immunity, Innate; RNA, Long Noncoding; Transcription Factors
PubMed: 35720331
DOI: 10.3389/fimmu.2022.905899 -
Proceedings of the National Academy of... Jun 2016Drosophila larval locomotion, which entails rhythmic body contractions, is controlled by sensory feedback from proprioceptors. The molecular mechanisms mediating this...
Drosophila larval locomotion, which entails rhythmic body contractions, is controlled by sensory feedback from proprioceptors. The molecular mechanisms mediating this feedback are little understood. By using genetic knock-in and immunostaining, we found that the Drosophila melanogaster transmembrane channel-like (tmc) gene is expressed in the larval class I and class II dendritic arborization (da) neurons and bipolar dendrite (bd) neurons, both of which are known to provide sensory feedback for larval locomotion. Larvae with knockdown or loss of tmc function displayed reduced crawling speeds, increased head cast frequencies, and enhanced backward locomotion. Expressing Drosophila TMC or mammalian TMC1 and/or TMC2 in the tmc-positive neurons rescued these mutant phenotypes. Bending of the larval body activated the tmc-positive neurons, and in tmc mutants this bending response was impaired. This implicates TMC's roles in Drosophila proprioception and the sensory control of larval locomotion. It also provides evidence for a functional conservation between Drosophila and mammalian TMCs.
Topics: Animals; Animals, Genetically Modified; Cell Line; Drosophila Proteins; Drosophila melanogaster; Larva; Locomotion; Membrane Proteins; Mutation; Neurons
PubMed: 27298354
DOI: 10.1073/pnas.1606537113 -
The EMBO Journal Jun 2023The Hippo pathway is an evolutionarily conserved pathway with crucial roles in development, organ size control, tissue homeostasis and cancer. Over two decades of...
The Hippo pathway is an evolutionarily conserved pathway with crucial roles in development, organ size control, tissue homeostasis and cancer. Over two decades of research have elucidated the core Hippo pathway kinase cascade, but its precise organization has not been fully understood. In this issue of The EMBO Journal, Qi et al (2023) report a new model of two modules for the Hippo kinase cascade, providing new insights into this long-standing question.
Topics: Humans; Hippo Signaling Pathway; Protein Serine-Threonine Kinases; Signal Transduction; Drosophila Proteins; Neoplasms
PubMed: 37073568
DOI: 10.15252/embj.2023113970