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The Drosophila Chromodomain Protein Kismet Activates Steroid Hormone Receptor Transcription to Govern Axon Pruning and Memory In Vivo. iScience 2019; 16:79-93. [PMID: 31153043 PMCID: PMC6543131 DOI: 10.1016/j.isci.2019.05.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 02/08/2019] [Accepted: 05/13/2019] [Indexed: 11/23/2022] Open
Abstract
Axon pruning is critical for sculpting precise neural circuits. Although axon pruning has been described in the literature for decades, relatively little is known about the molecular and cellular mechanisms that govern axon pruning in vivo. Here, we show that the epigenetic reader Kismet (Kis) is required for developmental axon pruning in Drosophila mushroom bodies. Kis binds to cis-regulatory elements of the steroid hormone receptor ecdysone receptor (ecr) gene and is necessary for activating expression of EcR-B1. Kis promotes the active H3K36 di- and tri-methylation and H4K16 acetylation histone marks at the ecr locus. We show that transgenic EcR-B1 can rescue axon pruning and memory defects associated with loss of Kis and that the histone deacetylase inhibitor SAHA also rescues these phenotypes. EcR protein abundance is the cell-autonomous, rate-limiting step required to initiate axon pruning in Drosophila, and our data suggest this step is under the epigenetic control of Kis.
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2
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Nouhaud P, Mallard F, Poupardin R, Barghi N, Schlötterer C. High-throughput fecundity measurements in Drosophila. Sci Rep 2018. [PMID: 29535355 PMCID: PMC5849729 DOI: 10.1038/s41598-018-22777-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Fecundity is probably the most frequently studied fitness component in Drosophila. Nevertheless, currently used methods to measure fecundity are not well-suited for large-scale experiments, with many populations being assayed in parallel. Here we present a standardized pipeline to measure fecundity in many Drosophila population samples with substantially reduced hand on times. Using a high-contrast medium for egg laying, we developed a Java plug-in for ImageJ to quantify the number of eggs by image processing. We show that our method is fast and provides reliable egg counts.
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Affiliation(s)
- Pierre Nouhaud
- Institut für Populationsgenetik, Vetmeduni, Vienna, Austria
| | - François Mallard
- Institut für Populationsgenetik, Vetmeduni, Vienna, Austria.,UMR 8197 IBENS, Paris, France
| | | | - Neda Barghi
- Institut für Populationsgenetik, Vetmeduni, Vienna, Austria
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3
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Ruland C, Berlandi J, Eikmeier K, Weinert T, Lin FJ, Ambree O, Seggewiss J, Paulus W, Jeibmann A. Decreased cerebral Irp-1B limits impact of social isolation in wild type and Alzheimer's disease modeled in Drosophila melanogaster. GENES BRAIN AND BEHAVIOR 2018; 17:e12451. [PMID: 29251829 DOI: 10.1111/gbb.12451] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 12/13/2017] [Accepted: 12/13/2017] [Indexed: 11/27/2022]
Abstract
Environmental factors, such as housing conditions and cognitively stimulating activities, have been shown to affect behavioral phenotypes and to modulate neurodegenerative conditions such as Alzheimer's disease (AD). AD is a progressive neurodegenerative disorder affecting cognitive functions. Epidemiological evidence and experimental studies using rodent models have indicated that social interaction reduces development and progression of disease. Drosophila models of Aβ42-associated AD lead to AD-like phenotypes, such as long-term memory impairment, locomotor and survival deficits, while effects of environmental conditions on AD-associated phenotypes have not been assessed in the fly. Here, we show that single housing reduced survival and motor performance of Aβ42 expressing and control flies. Gene expression analyses of Aβ42 expressing and control flies that had been exposed to different housing conditions showed upregulation of Iron regulatory protein 1B (Irp-1B) in fly brains following single housing. Downregulating Irp-1B in neurons of single-housed Aβ42 expressing and control flies rescued both survival and motor performance deficits. Thus, we provide novel evidence that increased cerebral expression of Irp-1B may underlie worsened behavioral outcome in socially deprived flies and can additionally modulate AD-like phenotypes.
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Affiliation(s)
- C Ruland
- Institute of Neuropathology, University Hospital Münster, Münster, Germany.,Department of Psychiatry, University of Münster, Münster, Germany
| | - J Berlandi
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - K Eikmeier
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - T Weinert
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - F J Lin
- Department of Biology, Coastal Carolina University, Conway, South Carolina
| | - O Ambree
- Department of Psychiatry, University of Münster, Münster, Germany.,Department of Behavioral Biology, University of Osnabrück, Osnabrück, Germany
| | - J Seggewiss
- Institute for Human Genetics, University Hospital Münster, Münster, Germany
| | - W Paulus
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - A Jeibmann
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
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Bademosi AT, Lauwers E, Amor R, Verstreken P, van Swinderen B, Meunier FA. In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal. J Vis Exp 2018. [PMID: 29364242 PMCID: PMC5908646 DOI: 10.3791/56952] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
An increasing number of super-resolution microscopy techniques are helping to uncover the mechanisms that govern the nanoscale cellular world. Single-molecule imaging is gaining momentum as it provides exceptional access to the visualization of individual molecules in living cells. Here, we describe a technique that we developed to perform single-particle tracking photo-activated localization microscopy (sptPALM) in Drosophila larvae. Synaptic communication relies on key presynaptic proteins that act by docking, priming, and promoting the fusion of neurotransmitter-containing vesicles with the plasma membrane. A range of protein-protein and protein-lipid interactions tightly regulates these processes and the presynaptic proteins therefore exhibit changes in mobility associated with each of these key events. Investigating how mobility of these proteins correlates with their physiological function in an intact live animal is essential to understanding their precise mechanism of action. Extracting protein mobility with high resolution in vivo requires overcoming limitations such as optical transparency, accessibility, and penetration depth. We describe how photoconvertible fluorescent proteins tagged to the presynaptic protein Syntaxin-1A can be visualized via slight oblique illumination and tracked at the motor nerve terminal or along the motor neuron axon of the third instar Drosophila larva.
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Affiliation(s)
- Adekunle T Bademosi
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland
| | - Elsa Lauwers
- VIB Centre for Brain and Disease Research, KU Leuven Department of Neurosciences, Leuven Institute for Neurodegenerative Disease (LIND)
| | - Rumelo Amor
- Queensland Brain Institute, The University of Queensland
| | - Patrik Verstreken
- VIB Centre for Brain and Disease Research, KU Leuven Department of Neurosciences, Leuven Institute for Neurodegenerative Disease (LIND)
| | | | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland;
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Burggren W, Souder BM, Ho DH. Metabolic rate and hypoxia tolerance are affected by group interactions and sex in the fruit fly ( Drosophila melanogaster): new data and a literature survey. Biol Open 2017; 6:471-480. [PMID: 28202465 PMCID: PMC5399560 DOI: 10.1242/bio.023994] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Population density and associated behavioral adjustments are potentially important in regulating physiological performance in many animals. In r-selected species like the fruit fly (Drosophila), where population density rapidly shifts in unpredictable and unstable environments, density-dependent physiological adjustments may aid survival of individuals living in a social environment. Yet, how population density (and associated social behaviors) affects physiological functions like metabolism is poorly understood in insects. Additionally, insects often show marked sexual dimorphism (larger females). Thus, in this study on D. melanogaster, we characterized the effects of fly density and sex on both mass-specific routine oxygen consumption (V̇O2) and hypoxia tolerance (PCrit). Females had significantly lower routine V̇O2 (∼4 µl O2 mg−1 h−1) than males (∼6 µl O2 mg−1 h−1) at an average fly density of 28 flies·respirometer chamber−1. However, V̇O2 was inversely related to fly density in males, with V̇O2 ranging from 4 to 11 µl O2 mg−1 h−1 at a density of 10 and 40 flies·chamber−1, respectively (r2=0.58, P<0.001). Female flies showed a similar but less pronounced effect, with a V̇O2 of 4 and 7 µl O2 mg−1 h−1 at a density of 10 and 40 flies·chamber−1, respectively (r2=0.43, P<0.001). PCrit (∼5.5 to 7.5 kPa) varied significantly with density in male (r2=0.50, P<0.01) but not female (r2=0.02, P>0.5) flies, with higher fly densities having a lower PCrit. An extensive survey of the literature on metabolism in fruit flies indicates that not all studies control for, or even report on, fly density and gender, both of which may affect metabolic measurements. Summary: Technical advances allowing oxygen consumption measurement in individual fruit flies actually take them out of their normal highly social context, resulting in higher oxygen consumption rates than in natural groups.
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Affiliation(s)
- Warren Burggren
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - BriAnna M Souder
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Dao H Ho
- Department of Clinical Investigation, Tripler Army Medical Center, Honolulu, HI 96859, USA
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Ghosh R, Vegesna S, Safi R, Bao H, Zhang B, Marenda DR, Liebl FLW. Kismet positively regulates glutamate receptor localization and synaptic transmission at the Drosophila neuromuscular junction. PLoS One 2014; 9:e113494. [PMID: 25412171 PMCID: PMC4239079 DOI: 10.1371/journal.pone.0113494] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 10/24/2014] [Indexed: 12/20/2022] Open
Abstract
The Drosophila neuromuscular junction (NMJ) is a glutamatergic synapse that is structurally and functionally similar to mammalian glutamatergic synapses. These synapses can, as a result of changes in activity, alter the strength of their connections via processes that require chromatin remodeling and changes in gene expression. The chromodomain helicase DNA binding (CHD) protein, Kismet (Kis), is expressed in both motor neuron nuclei and postsynaptic muscle nuclei of the Drosophila larvae. Here, we show that Kis is important for motor neuron synaptic morphology, the localization and clustering of postsynaptic glutamate receptors, larval motor behavior, and synaptic transmission. Our data suggest that Kis is part of the machinery that modulates the development and function of the NMJ. Kis is the homolog to human CHD7, which is mutated in CHARGE syndrome. Thus, our data suggest novel avenues of investigation for synaptic defects associated with CHARGE syndrome.
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Affiliation(s)
- Rupa Ghosh
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Srikar Vegesna
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Ramia Safi
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
| | - Hong Bao
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Bing Zhang
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Daniel R. Marenda
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail: (FLWL); (DRM)
| | - Faith L. W. Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
- * E-mail: (FLWL); (DRM)
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Chi MW, Griffith LC, Vecsey CG. Larval Population Density Alters Adult Sleep in Wild-Type Drosophila melanogaster but Not in Amnesiac Mutant Flies. Brain Sci 2014; 4:453-70. [PMID: 25116571 PMCID: PMC4194033 DOI: 10.3390/brainsci4030453] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 06/27/2014] [Accepted: 06/28/2014] [Indexed: 01/02/2023] Open
Abstract
Sleep has many important biological functions, but how sleep is regulated remains poorly understood. In humans, social isolation and other stressors early in life can disrupt adult sleep. In fruit flies housed at different population densities during early adulthood, social enrichment was shown to increase subsequent sleep, but it is unknown if population density during early development can also influence adult sleep. To answer this question, we maintained Drosophila larvae at a range of population densities throughout larval development, kept them isolated during early adulthood, and then tested their sleep patterns. Our findings reveal that flies that had been isolated as larvae had more fragmented sleep than those that had been raised at higher population densities. This effect was more prominent in females than in males. Larval population density did not affect sleep in female flies that were mutant for amnesiac, which has been shown to be required for normal memory consolidation, adult sleep regulation, and brain development. In contrast, larval population density effects on sleep persisted in female flies lacking the olfactory receptor or83b, suggesting that olfactory signals are not required for the effects of larval population density on adult sleep. These findings show that population density during early development can alter sleep behavior in adulthood, suggesting that genetic and/or structural changes are induced by this developmental manipulation that persist through metamorphosis.
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Affiliation(s)
- Michael W Chi
- National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA.
| | - Leslie C Griffith
- National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA.
| | - Christopher G Vecsey
- National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA.
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Kisiel M, Majumdar D, Campbell S, Stewart BA. Myosin VI contributes to synaptic transmission and development at the Drosophila neuromuscular junction. BMC Neurosci 2011; 12:65. [PMID: 21745401 PMCID: PMC3146895 DOI: 10.1186/1471-2202-12-65] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 07/11/2011] [Indexed: 12/15/2022] Open
Abstract
Background Myosin VI, encoded by jaguar (jar) in Drosophila melanogaster, is a unique member of the myosin superfamily of actin-based motor proteins. Myosin VI is the only myosin known to move towards the minus or pointed ends of actin filaments. Although Myosin VI has been implicated in numerous cellular processes as both an anchor and a transporter, little is known about the role of Myosin VI in the nervous system. We previously recovered jar in a screen for genes that modify neuromuscular junction (NMJ) development and here we report on the genetic analysis of Myosin VI in synaptic development and function using loss of function jar alleles. Results Our experiments on Drosophila third instar larvae revealed decreased locomotor activity, a decrease in NMJ length, a reduction in synaptic bouton number, and altered synaptic vesicle localization in jar mutants. Furthermore, our studies of synaptic transmission revealed alterations in both basal synaptic transmission and short-term plasticity at the jar mutant neuromuscular synapse. Conclusions Altogether these findings indicate that Myosin VI is important for proper synaptic function and morphology. Myosin VI may be functioning as an anchor to tether vesicles to the bouton periphery and, thereby, participating in the regulation of synaptic vesicle mobilization during synaptic transmission.
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Affiliation(s)
- Marta Kisiel
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd, Mississauga, ON L5L1C6, Canada
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Ellis LL, Carney GE. Socially-responsive gene expression in male Drosophila melanogaster is influenced by the sex of the interacting partner. Genetics 2011; 187:157-69. [PMID: 20980240 PMCID: PMC3018301 DOI: 10.1534/genetics.110.122754] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 10/20/2010] [Indexed: 11/18/2022] Open
Abstract
Behavior is influenced by an organism's genes and environment, including its interactions with same or opposite sex individuals. Drosophila melanogaster perform innate, yet socially modifiable, courtship behaviors that are sex specific and require rapid integration and response to multiple sensory cues. Furthermore, males must recognize and distinguish other males from female courtship objects. It is likely that perception, integration, and response to sex-specific cues is partially mediated by changes in gene expression. Reasoning that social interactions with members of either sex would impact gene expression, we compared expression profiles in heads of males that courted females, males that interacted with other males, or males that did not interact with another fly. Expression of 281 loci changes when males interact with females, whereas 505 changes occur in response to male-male interactions. Of these genes, 265 are responsive to encounters with either sex and 240 respond specifically to male-male interactions. Interestingly, 16 genes change expression only when a male courts a female, suggesting that these changes are a specific response to male-female courtship interactions. We supported our hypothesis that socially-responsive genes can function in behavior by showing that egghead (egh) expression, which increases during social interactions, is required for robust male-to-female courtship. We predict that analyzing additional socially-responsive genes will give us insight into genes and neural signaling pathways that influence reproductive and other behavioral interactions.
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Affiliation(s)
| | - Ginger E. Carney
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258
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10
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Mating alters gene expression patterns in Drosophila melanogaster male heads. BMC Genomics 2010; 11:558. [PMID: 20937114 PMCID: PMC3091707 DOI: 10.1186/1471-2164-11-558] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 10/11/2010] [Indexed: 11/28/2022] Open
Abstract
Background Behavior is a complex process resulting from the integration of genetic and environmental information. Drosophila melanogaster rely on multiple sensory modalities for reproductive success, and mating causes physiological changes in both sexes that affect reproductive output or behavior. Some of these effects are likely mediated by changes in gene expression. Courtship and mating alter female transcript profiles, but it is not known how mating affects male gene expression. Results We used Drosophila genome arrays to identify changes in gene expression profiles that occur in mated male heads. Forty-seven genes differed between mated and control heads 2 hrs post mating. Many mating-responsive genes are highly expressed in non-neural head tissues, including an adipose tissue called the fat body. One fat body-enriched gene, female-specific independent of transformer (fit), is a downstream target of the somatic sex-determination hierarchy, a genetic pathway that regulates Drosophila reproductive behaviors as well as expression of some fat-expressed genes; three other mating-responsive loci are also downstream components of this pathway. Another mating-responsive gene expressed in fat, Juvenile hormone esterase (Jhe), is necessary for robust male courtship behavior and mating success. Conclusions Our study demonstrates that mating causes changes in male head gene expression profiles and supports an increasing body of work implicating adipose signaling in behavior modulation. Since several mating-induced genes are sex-determination hierarchy target genes, additional mating-responsive loci may be downstream components of this pathway as well.
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Lorenzo DN, Li MG, Mische SE, Armbrust KR, Ranum LPW, Hays TS. Spectrin mutations that cause spinocerebellar ataxia type 5 impair axonal transport and induce neurodegeneration in Drosophila. ACTA ACUST UNITED AC 2010; 189:143-58. [PMID: 20368622 PMCID: PMC2854382 DOI: 10.1083/jcb.200905158] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
How spectrin mutations caused Purkinje cell death becomes clearer following studies that examined the effect of expressing mutant SCA5 in the fly eye. Mutant spectrin causes deficits in synapse formation at the neuromuscular junction and disrupts vesicular trafficking. Spinocerebellar ataxia type 5 (SCA5) is an autosomal dominant neurodegenerative disorder caused by mutations in the SPBTN2 gene encoding β-III–spectrin. To investigate the molecular basis of SCA5, we established a series of transgenic Drosophila models that express human β-III–spectrin or fly β-spectrin proteins containing SCA5 mutations. Expression of the SCA5 mutant spectrin in the eye causes a progressive neurodegenerative phenotype, and expression in larval neurons results in posterior paralysis, reduced synaptic terminal growth, and axonal transport deficits. These phenotypes are genetically enhanced by both dynein and dynactin loss-of-function mutations. In summary, we demonstrate that SCA5 mutant spectrin causes adult-onset neurodegeneration in the fly eye and disrupts fundamental intracellular transport processes that are likely to contribute to this progressive neurodegenerative disease.
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Affiliation(s)
- Damaris N Lorenzo
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
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12
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Abstract
In vertebrates, sialylated glycans participate in a wide range of biological processes and affect the development and function of the nervous system. While the complexity of glycosylation and the functional redundancy among sialyltransferases provide obstacles for revealing biological roles of sialylation in mammals, Drosophila possesses a sole vertebrate-type sialyltransferase, Drosophila sialyltransferase (DSiaT), with significant homology to its mammalian counterparts, suggesting that Drosophila could be a suitable model to investigate the function of sialylation. To explore this possibility and investigate the role of sialylation in Drosophila, we inactivated DSiaT in vivo by gene targeting and analyzed phenotypes of DSiaT mutants using a combination of behavioral, immunolabeling, electrophysiological, and pharmacological approaches. Our experiments demonstrated that DSiaT expression is restricted to a subset of CNS neurons throughout development. We found that DSiaT mutations result in significantly decreased life span, locomotor abnormalities, temperature-sensitive paralysis, and defects of neuromuscular junctions. Our results indicate that DSiaT regulates neuronal excitability and affects the function of a voltage-gated sodium channel. Finally, we showed that sialyltransferase activity is required for DSiaT function in vivo, which suggests that DSiaT mutant phenotypes result from a defect in sialylation of N-glycans. This work provided the first evidence that sialylation has an important biological function in protostomes, while also revealing a novel, nervous system-specific function of alpha2,6-sialylation. Thus, our data shed light on one of the most ancient functions of sialic acids in metazoan organisms and suggest a possibility that this function is evolutionarily conserved between flies and mammals.
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Kristiansen LV, Hortsch M. Fasciclin II: the NCAM ortholog in Drosophila melanogaster. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 663:387-401. [PMID: 20017035 DOI: 10.1007/978-1-4419-1170-4_24] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Lars V Kristiansen
- Department of Cell and Developmental Biology, University of Michigan, 109 Zina Pitcher Place, 3063 Biomedical Sciences Research Bldg (BSRB), Ann Arbor, MI 48109-2200, USA
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14
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Ueda A, Wu CF. Effects of social isolation on neuromuscular excitability and aggressive behaviors in Drosophila: altered responses by Hk and gsts1, two mutations implicated in redox regulation. J Neurogenet 2009; 23:378-94. [PMID: 19863269 PMCID: PMC3632667 DOI: 10.3109/01677060903063026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Social deprivation is known to trigger a variety of behavioral and physiological modifications in animal species, but the underlying genetic and cellular mechanisms are not fully understood. As we described previously, adult female flies reared in isolation show increased frequency of aggressive behaviors than those reared in a group. Here, we report that isolated rearing also caused significantly altered nerve and muscle excitability and enhanced synaptic transmission at larval neuromuscular junctions (NMJs). We found that mutations of two genes, Hyperkinetic (Hk) and glutathione S-transferase-S1 (gsts1), alter the response to social isolation in Drosophila. Hk and gsts1 mutations increased adult female aggression and larval neuromuscular hyperexcitability, even when reared in a group. Unlike wild type, these behavioral and electrophysiological phenotypes were not further enhanced in these mutants by isolated rearing. Products of these two genes have been implicated in reactive oxygen species (ROS) metabolism. We previously reported in these mutants increased signals from an ROS probe at larval NMJs, and this study revealed distinct effects of isolation rearing on these mutants, compared to the control larvae in ROS-probe signals. Our data further demonstrated modified nerve and muscle excitability by a reducing agent, dithiothreitol. Our results suggest that altered cellular ROS regulation can exert pleiotropic effects on nerve, synapse, and muscle functions and may involve different redox mechanisms in different cell types to modify behavioral expressions. Therefore, ROS regulation may take part in the cellular responses to social isolation stress, underlying an important form of neural and behavioral plasticity.
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Affiliation(s)
- Atsushi Ueda
- Department of Biology, University of Iowa, Iowa City, Iowa 52242, USA.
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15
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Boylan KLM, Mische S, Li M, Marqués G, Morin X, Chia W, Hays TS. Motility screen identifies Drosophila IGF-II mRNA-binding protein--zipcode-binding protein acting in oogenesis and synaptogenesis. PLoS Genet 2008; 4:e36. [PMID: 18282112 PMCID: PMC2242817 DOI: 10.1371/journal.pgen.0040036] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 12/26/2007] [Indexed: 01/27/2023] Open
Abstract
The localization of specific mRNAs can establish local protein gradients that generate and control the development of cellular asymmetries. While all evidence underscores the importance of the cytoskeleton in the transport and localization of RNAs, we have limited knowledge of how these events are regulated. Using a visual screen for motile proteins in a collection of GFP protein trap lines, we identified the Drosophila IGF-II mRNA-binding protein (Imp), an ortholog of Xenopus Vg1 RNA binding protein and chicken zipcode-binding protein. In Drosophila, Imp is part of a large, RNase-sensitive complex that is enriched in two polarized cell types, the developing oocyte and the neuron. Using time-lapse confocal microscopy, we establish that both dynein and kinesin contribute to the transport of GFP-Imp particles, and that regulation of transport in egg chambers appears to differ from that in neurons. In Drosophila, loss-of-function Imp mutations are zygotic lethal, and mutants die late as pharate adults. Imp has a function in Drosophila oogenesis that is not essential, as well as functions that are essential during embryogenesis and later development. Germline clones of Imp mutations do not block maternal mRNA localization or oocyte development, but overexpression of a specific Imp isoform disrupts dorsal/ventral polarity. We report here that loss-of-function Imp mutations, as well as Imp overexpression, can alter synaptic terminal growth. Our data show that Imp is transported to the neuromuscular junction, where it may modulate the translation of mRNA targets. In oocytes, where Imp function is not essential, we implicate a specific Imp domain in the establishment of dorsoventral polarity.
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Affiliation(s)
- Kristin L. M Boylan
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Sarah Mische
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Mingang Li
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Guillermo Marqués
- Department of Cell Biology, The University of Alabama at Birmingham, Alabama, United States of America
| | - Xavier Morin
- Institut de Biologie du Développement de Marseille-Luminy (IBDML), CNRS UMR6216 INSERM-Université de la Méditerrannée, Marseilles, France
| | - William Chia
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
| | - Thomas S Hays
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota, United States of America
- * To whom correspondence should be addressed. E-mail:
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Haines N, Seabrooke S, Stewart BA. Dystroglycan and protein O-mannosyltransferases 1 and 2 are required to maintain integrity of Drosophila larval muscles. Mol Biol Cell 2007; 18:4721-30. [PMID: 17881734 PMCID: PMC2096576 DOI: 10.1091/mbc.e07-01-0047] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Accepted: 09/11/2007] [Indexed: 11/11/2022] Open
Abstract
In vertebrates, mutations in Protein O-mannosyltransferase1 (POMT1) or POMT2 are associated with muscular dystrophy due to a requirement for O-linked mannose glycans on the Dystroglycan (Dg) protein. In this study we examine larval body wall muscles of Drosophila mutant for Dg, or RNA interference knockdown for Dg and find defects in muscle attachment, altered muscle contraction, and a change in muscle membrane resistance. To determine if POMTs are required for Dg function in Drosophila, we examine larvae mutant for genes encoding POMT1 or POMT2. Larvae mutant for either POMT, or doubly mutant for both, show muscle attachment and muscle contraction phenotypes identical to those associated with reduced Dg function, consistent with a requirement for O-linked mannose on Drosophila Dg. Together these data establish a central role for Dg in maintaining integrity in Drosophila larval muscles and demonstrate the importance of glycosylation to Dg function in Drosophila. This study opens the possibility of using Drosophila to investigate muscular dystrophy.
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Affiliation(s)
- Nicola Haines
- Department of Biology, University of Toronto, Mississauga, ON, Canada L5L 1C6.
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Haines N, Stewart BA. Functional roles for beta1,4-N-acetlygalactosaminyltransferase-A in Drosophila larval neurons and muscles. Genetics 2007; 175:671-9. [PMID: 17151241 PMCID: PMC1800592 DOI: 10.1534/genetics.106.065565] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Accepted: 11/07/2006] [Indexed: 11/18/2022] Open
Abstract
Adult Drosophila mutant for the glycosyltransferase beta1,4-N-acetlygalactosaminyltransferase-A (beta4GalNAcTA) display an abnormal locomotion phenotype, indicating a role for this enzyme, and the glycan structures that it generates, in the neuromuscular system. To investigate the functional role of this enzyme in more detail, we turned to the accessible larval neuromuscular system and report here that larvae mutant for beta4GalNAcTA display distinct nerve and muscle phenotypes. Mutant larvae exhibit abnormal backward crawling, reductions in nerve terminal bouton number, decreased spontaneous transmitter-release frequency, and short, wide muscles. This muscle shape change appears to result from hypercontraction since the individual sarcomeres are shorter in mutant muscles. Analysis of muscle calcium signals showed altered calcium handling in the mutant, suggesting a mechanism by which hypercontraction could occur. All of these phenotypes can be rescued by a transgene carrying the beta4GalNAcTA genomic region. Tissue-specific expression, using the Gal4-UAS system, reveals that neural expression rescues the mutant crawling phenotype, while muscle expression rescues the muscle defect. Tissue-specific expression did not appear to rescue the decrease in neuromuscular junction bouton number, suggesting that this defect arises from cooperation between nerve and muscle. Altogether, these results suggest that beta4GalNAcTA has at least three distinct functional roles.
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Affiliation(s)
- Nicola Haines
- Department of Biology, University of Toronto, Mississauga, Ontario L5L 1C6, Canada.
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