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Sample records for drosophila dishevelled segment-polarity

  1. Human homologue sequences to the Drosophila dishevelled segment-polarity gene are deleted in the DiGeorge syndrome

    SciTech Connect

    Pizzuti, A.; Ratti, A.; Penso, D.; Silani, V.; Scarlato, G.

    1996-04-01

    DiGeorge syndrome (DGS) is a developmental defect of some of the neural crest derivatives. Most DGS patients show haploinsufficiency due to interstitial deletions of the proximal long arm of chromosome 22. Deletions of 22q11 have also been reported in patients with the velo-cardio-facial syndrome and familial conotruncal heart defects. It has been suggested that the wide phenotype spectrum associated with 22q11 monosomy is a consequence of contiguous-gene deletions. We report the isolation of human cDNAs homologous to the Drosophila dishevelled (dsh) segment-polarity gene. Sequences homologous to the 3{prime} UTR of these transcripts (DVL-22) were positioned within the DGS critical region and were found to be deleted in DGS patients. Human DVL mRNAs are expressed in several fetal and adult tissues, including the thymus and, at high levels, the heart. Two transcripts, 3.2 and 5 kb, were detected, in Northern blot analysis, with different expression patterns in the surveyed tissues when different cDNAs were used. The isolated cDNAs exhibit high amino acid homology with the mouse and Xenopus Dvl-1 gene, the only other vertebrate dsh homologues so far isolated. The pivotal role of dsh in fly development suggests an analogous key function in vertebrate embryogenesis of its homologue genes. Since DGS may be due to perturbation of differentiation mechanisms at decisive embryological stages, a Dsh-like gene in the small-region overlap (SRO) might be a candidate for the pathogenesis of this disorder. 52 refs., 3 figs.

  2. Human homologue sequences to the Drosophila dishevelled segment-polarity gene are deleted in the DiGeorge syndrome.

    PubMed

    Pizzuti, A; Novelli, G; Mari, A; Ratti, A; Colosimo, A; Amati, F; Penso, D; Sangiuolo, F; Calabrese, G; Palka, G; Silani, V; Gennarelli, M; Mingarelli, R; Scarlato, G; Scambler, P; Dallapiccola, B

    1996-04-01

    DiGeorge syndrome (DGS) is a developmental defect of some of the neural crest derivatives. Most DGS patients show haploinsufficiency due to interstitial deletions of the proximal long arm of chromosome 22. Deletions of 22q11 have also been reported with patients with the velocardio-facial syndrome and familial conotruncal heart defects. It has been suggested that the wide phenotype spectrum associated with 22q11 monosomy is a consequence of contiguous-gene deletions. We report the isolation of human cDNAs homologous to the Drosophila dishevelled (dsh) segment-polarity gene. Sequences homologous to the 3' UTR of these transcripts (DVL-22) were positioned within the DGS critical region and were found to be deleted in DGS patients. Human DVL mRNAs are expressed in several fetal and adult tissues, including the thymus and, at high levels, the heart. Two transcripts, 3.2 and 5kb, were detected, in northern blot analysis, with different expression patterns in the surveyed tissues when different cDNAs were used. The isolated cDNAs exhibit high amino acid homology with the mouse and Xenopus Dvl-1 gene, the only other vertebrate dsh homologues so far isolated. The pivotal role of dsh in fly development suggests an analogous key function in vertebrate embryogenesis of its homologue genes. Since DGS may be due to perturbation of differentiation mechanisms at decisive embryological stages, a Dsh-like gene in the small-region overlap (SRO) might be a candidate for the pathogenesis of this disorder.

  3. Human homologue sequences to the Drosophila dishevelled segment-polarity gene are deleted in the DiGeorge syndrome.

    PubMed Central

    Pizzuti, A.; Novelli, G.; Mari, A.; Ratti, A.; Colosimo, A.; Amati, F.; Penso, D.; Sangiuolo, F.; Calabrese, G.; Palka, G.; Silani, V.; Gennarelli, M.; Mingarelli, R.; Scarlato, G.; Scambler, P.; Dallapiccola, B.

    1996-01-01

    DiGeorge syndrome (DGS) is a developmental defect of some of the neural crest derivatives. Most DGS patients show haploinsufficiency due to interstitial deletions of the proximal long arm of chromosome 22. Deletions of 22q11 have also been reported with patients with the velocardio-facial syndrome and familial conotruncal heart defects. It has been suggested that the wide phenotype spectrum associated with 22q11 monosomy is a consequence of contiguous-gene deletions. We report the isolation of human cDNAs homologous to the Drosophila dishevelled (dsh) segment-polarity gene. Sequences homologous to the 3' UTR of these transcripts (DVL-22) were positioned within the DGS critical region and were found to be deleted in DGS patients. Human DVL mRNAs are expressed in several fetal and adult tissues, including the thymus and, at high levels, the heart. Two transcripts, 3.2 and 5kb, were detected, in northern blot analysis, with different expression patterns in the surveyed tissues when different cDNAs were used. The isolated cDNAs exhibit high amino acid homology with the mouse and Xenopus Dvl-1 gene, the only other vertebrate dsh homologues so far isolated. The pivotal role of dsh in fly development suggests an analogous key function in vertebrate embryogenesis of its homologue genes. Since DGS may be due to perturbation of differentiation mechanisms at decisive embryological stages, a Dsh-like gene in the small-region overlap (SRO) might be a candidate for the pathogenesis of this disorder. Images Figure 1 Figure 2 Figure 3 PMID:8644734

  4. Robustness and modular design of the Drosophila segment polarity network

    PubMed Central

    Ma, Wenzhe; Lai, Luhua; Ouyang, Qi; Tang, Chao

    2006-01-01

    Biomolecular networks have to perform their functions robustly. A robust function may have preferences in the topological structures of the underlying network. We carried out an exhaustive computational analysis on network topologies in relation to a patterning function in Drosophila embryogenesis. We found that whereas the vast majority of topologies can either not perform the required function or only do so very fragilely, a small fraction of topologies emerges as particularly robust for the function. The topology adopted by Drosophila, that of the segment polarity network, is a top ranking one among all topologies with no direct autoregulation. Furthermore, we found that all robust topologies are modular—each being a combination of three kinds of modules. These modules can be traced back to three subfunctions of the patterning function, and their combinations provide a combinatorial variability for the robust topologies. Our results suggest that the requirement of functional robustness drastically reduces the choices of viable topology to a limited set of modular combinations among which nature optimizes its choice under evolutionary and other biological constraints. PMID:17170765

  5. Drosophila RpS3a, a novel Minute gene situated between the segment polarity genescubitus interruptus and dTCF.

    PubMed

    van Beest, M; Mortin, M; Clevers, H

    1998-10-01

    Genetic analysis of the small chromosome 4 of Drosophila has been hampered by the virtual lack of recombination. The segment polarity gene cubitus interruptus (ci) maps to the most intensively studied locus on this chromosome. Up to four complementation groups have been found to be associated with ci. We and others have recently characterized a second segment polarity gene, dTCF or pan, 12 kb upstream of ci, in a head-to-head configuration. During the course of these studies we identified a transcription unit in the intergenic region. We report here the cloning of cDNAs from this transcription unit, which encode the Drosophila homologue of the human ribosomal protein S3a (RpS3a). The RpS3a gene is expressed ubiquitously and throughout development. A Minute allele, M(4)101, linked tightly to ci, was found to harbour an integration of a Doc retroposon in the promotor region of RpS3a. Thus, like other Minute loci, M(4)101 encodes a component of the protein synthesis machinery. These data further unravel the complex genetics surrounding the ci and dTCF loci.

  6. The segment polarity network is a robust developmental module

    NASA Astrophysics Data System (ADS)

    von Dassow, George; Meir, Eli; Munro, Edwin M.; Odell, Garrett M.

    2000-07-01

    All insects possess homologous segments, but segment specification differs radically among insect orders. In Drosophila, maternal morphogens control the patterned activation of gap genes, which encode transcriptional regulators that shape the patterned expression of pair-rule genes. This patterning cascade takes place before cellularization. Pair-rule gene products subsequently `imprint' segment polarity genes with reiterated patterns, thus defining the primordial segments. This mechanism must be greatly modified in insect groups in which many segments emerge only after cellularization. In beetles and parasitic wasps, for instance, pair-rule homologues are expressed in patterns consistent with roles during segmentation, but these patterns emerge within cellular fields. In contrast, although in locusts pair-rule homologues may not control segmentation, some segment polarity genes and their interactions are conserved. Perhaps segmentation is modular, with each module autonomously expressing a characteristic intrinsic behaviour in response to transient stimuli. If so, evolution could rearrange inputs to modules without changing their intrinsic behaviours. Here we suggest, using computer simulations, that the Drosophila segment polarity genes constitute such a module, and that this module is resistant to variations in the kinetic constants that govern its behaviour.

  7. Genetic and Cytogenetic Analysis of the 43a-E Region Containing the Segment Polarity Gene Costa and the Cellular Polarity Genes Prickle and Spiny-Legs in Drosophila Melanogaster

    PubMed Central

    Heitzler, P.; Coulson, D.; Saenz-Robles, M. T.; Ashburner, M.; Roote, J.; Simpson, P.; Gubb, D.

    1993-01-01

    A cytogenetic analysis of the 43A-E region of chromosome 2 in Drosophila melanogaster is presented. Within this interval 27 complementation groups have been identified by extensive F(2) screens and ordered by deletion mapping. The region includes the cellular polarity genes prickle and spiny-legs, the segmentation genes costa and torso, the morphogenetic locus sine oculis and is bounded on its distal side by the eye-color gene cinnabar. In addition 19 novel lethal complementation groups and two semi-lethal complementation groups with morphogenetic escaper phenotypes are described. PMID:8224812

  8. Diego and Prickle regulate Frizzled planar cell polarity signalling by competing for Dishevelled binding.

    PubMed

    Jenny, Andreas; Reynolds-Kenneally, Jessica; Das, Gishnu; Burnett, Micheal; Mlodzik, Marek

    2005-07-01

    Epithelial planar cell polarity (PCP) is evident in the cellular organization of many tissues in vertebrates and invertebrates. In mammals, PCP signalling governs convergent extension during gastrulation and the organization of a wide variety of structures, including the orientation of body hair and sensory hair cells of the inner ear. In Drosophila melanogaster, PCP is manifest in adult tissues, including ommatidial arrangement in the compound eye and hair orientation in wing cells. PCP establishment requires the conserved Frizzled/Dishevelled PCP pathway. Mutations in PCP-pathway-associated genes cause aberrant orientation of body hair or inner-ear sensory cells in mice, or misorientation of ommatidia and wing hair in D. melanogaster. Here we provide mechanistic insight into Frizzled/Dishevelled signalling regulation. We show that the ankyrin-repeat protein Diego binds directly to Dishevelled and promotes Frizzled signalling. Dishevelled can also be bound by the Frizzled PCP antagonist Prickle. Strikingly, Diego and Prickle compete with one another for Dishevelled binding, thereby modulating Frizzled/Dishevelled activity and ensuring tight control over Frizzled PCP signalling.

  9. The cellular story of dishevelleds

    PubMed Central

    Kafka, Anja; Bašić-Kinda, Sandra; Pećina-Šlaus, Nives

    2014-01-01

    Dishevelled (DVL) proteins, three of which have been identified in humans, are highly conserved components of canonical and noncanonical Wnt signaling pathways. These multifunctional proteins, originally discovered in the fruit fly, through their different domains mediate complex signal transduction: DIX (dishevelled, axin) and PDZ (postsynaptic density 95, discs large, zonula occludens-1) domains serve for canonical beta-catenin signaling, while PDZ and DEP (dishevelled, Egl-10, pleckstrin) domains serve for non-canonical signaling. In canonical or beta-catenin signaling, DVL forms large molecular supercomplexes at the plasma membrane consisting of Wnt-Fz-LRP5/6-DVL-AXIN. This promotes the disassembly of the beta-catenin destruction machinery, beta-catenin accumulation, and consequent activation of Wnt signaling. Therefore, DVLs are considered to be key regulators that rescue cytoplasmic beta-catenin from degradation. The potential medical importance of DVLs is in both human degenerative disease and cancer. The overexpression of DVL has been shown to potentiate the activation of Wnt signaling and it is now apparent that up-regulation of DVLs is involved in several types of cancer. PMID:25358879

  10. The cellular story of dishevelleds.

    PubMed

    Kafka, Anja; Bašić-Kinda, Sandra; Pećina-Šlaus, Nives

    2014-10-01

    Dishevelled (DVL) proteins, three of which have been identified in humans, are highly conserved components of canonical and noncanonical Wnt signaling pathways. These multifunctional proteins, originally discovered in the fruit fly, through their different domains mediate complex signal transduction: DIX (dishevelled, axin) and PDZ (postsynaptic density 95, discs large, zonula occludens-1) domains serve for canonical beta-catenin signaling, while PDZ and DEP (dishevelled, Egl-10, pleckstrin) domains serve for non-canonical signaling. In canonical or beta-catenin signaling, DVL forms large molecular supercomplexes at the plasma membrane consisting of Wnt-Fz-LRP5/6-DVL-AXIN. This promotes the disassembly of the beta-catenin destruction machinery, beta-catenin accumulation, and consequent activation of Wnt signaling. Therefore, DVLs are considered to be key regulators that rescue cytoplasmic beta-catenin from degradation. The potential medical importance of DVLs is in both human degenerative disease and cancer. The overexpression of DVL has been shown to potentiate the activation of Wnt signaling and it is now apparent that up-regulation of DVLs is involved in several types of cancer.

  11. Disinhibition of the HECT E3 ubiquitin ligase WWP2 by polymerized Dishevelled

    PubMed Central

    Mund, Thomas; Graeb, Michael; Mieszczanek, Juliusz; Gammons, Melissa; Pelham, Hugh R. B.; Bienz, Mariann

    2015-01-01

    Dishevelled is a pivot in Wnt signal transduction, controlling both β-catenin-dependent transcription to specify proliferative cell fates, and cell polarity and other non-nuclear events in post-mitotic cells. In response to Wnt signals, or when present at high levels, Dishevelled forms signalosomes by dynamic polymerization. Its levels are controlled by ubiquitylation, mediated by various ubiquitin ligases, including NEDD4 family members that bind to a conserved PPxY motif in Dishevelled (mammalian Dvl1–3). Here, we show that Dvl2 binds to the ubiquitin ligase WWP2 and unlocks its ligase activity from autoinhibition. This disinhibition of WWP2 depends on several features of Dvl2 including its PPxY motif and to a lesser extent its DEP domain, but crucially on the ability of Dvl2 to polymerize, indicating that WWP2 is activated in Wnt signalosomes. We show that Notch intracellular domains are substrates for Dvl-activated WWP2 and their transcriptional activity is consequently reduced, providing a molecular mechanism for cross-talk between Wnt and Notch signalling. These regulatory interactions are conserved in Drosophila whose WWP2 orthologue, Suppressor-of-deltex, downregulates Notch signalling upon activation by Dishevelled in developing wing tissue. Attentuation of Notch signalling by Dishevelled signalosomes could be important during the transition of cells from the proliferative to the post-mitotic state. PMID:26701932

  12. PTEN regulates cilia through Dishevelled

    PubMed Central

    Shnitsar, Iryna; Bashkurov, Mikhail; Masson, Glenn R.; Ogunjimi, Abiodun A.; Mosessian, Sherly; Cabeza, Eduardo Aguiar; Hirsch, Calley L.; Trcka, Daniel; Gish, Gerald; Jiao, Jing; Wu, Hong; Winklbauer, Rudolf; Williams, Roger L.; Pelletier, Laurence; Wrana, Jeffrey L.; Barrios-Rodiles, Miriam

    2015-01-01

    Cilia are hair-like cellular protrusions important in many aspects of eukaryotic biology. For instance, motile cilia enable fluid movement over epithelial surfaces, while primary (sensory) cilia play roles in cellular signalling. The molecular events underlying cilia dynamics, and particularly their disassembly, are not well understood. Phosphatase and tensin homologue (PTEN) is an extensively studied tumour suppressor, thought to primarily act by antagonizing PI3-kinase signalling. Here we demonstrate that PTEN plays an important role in multicilia formation and cilia disassembly by controlling the phosphorylation of Dishevelled (DVL), another ciliogenesis regulator. DVL is a central component of WNT signalling that plays a role during convergent extension movements, which we show here are also regulated by PTEN. Our studies identify a novel protein substrate for PTEN that couples PTEN to regulation of cilia dynamics and WNT signalling, thus advancing our understanding of potential underlying molecular etiologies of PTEN-related pathologies. PMID:26399523

  13. Establishment of segment polarity in the ectoderm of the leech Helobdella

    NASA Technical Reports Server (NTRS)

    Seaver, E. C.; Shankland, M.

    2001-01-01

    The segmented ectoderm and mesoderm of the leech arise via a stereotyped cell lineage from embryonic stem cells called teloblasts. Each teloblast gives rise to a column of primary blast cell daughters, and the blast cells generate descendant clones that serve as the segmental repeats of their particular teloblast lineage. We have examined the mechanism by which the leech primary blast cell clones acquire segment polarity - i.e. a fixed sequence of positional values ordered along the anteroposterior axis of the segmental repeat. In the O and P teloblast lineages, the earliest divisions of the primary blast cell segregate anterior and posterior cell fates along the anteroposterior axis. Using a laser microbeam, we ablated single cells from both o and p blast cell clones at stages when the clone was two to four cells in length. The developmental fate of the remaining cells was characterized with rhodamine-dextran lineage tracer. Twelve different progeny cells were ablated, and in every case the ablation eliminated the normal descendants of the ablated cell while having little or no detectable effect on the developmental fate of the remaining cells. This included experiments in which we specifically ablated those blast cell progeny that are known to express the engrailed gene, or their lineal precursors. These findings confirm and extend a previous study by showing that the establishment of segment polarity in the leech ectoderm is largely independent of cell interactions conveyed along the anteroposterior axis. Both intercellular signaling and engrailed expression play an important role in the segment polarity specification of the Drosophila embryo, and our findings suggest that there may be little or no conservation of this developmental mechanism between those two organisms.

  14. Wnt signalling antagonizes stress granule assembly through a Dishevelled-dependent mechanism

    PubMed Central

    Sahoo, Pabitra K.; Murawala, Prayag; Sawale, Pravin T.; Sahoo, Manas R.; Tripathi, Mukesh M.; Gaikwad, Swati R.; Seshadri, Vasudevan; Joseph, Jomon

    2012-01-01

    Summary Cells often respond to diverse environmental stresses by inducing stress granules (SGs) as an adaptive mechanism. SGs are generally assembled as a result of aggregation of mRNAs stalled in a translational pre-initiation complex, mediated by a set of RNA-binding proteins such as G3BP and TIA-1. SGs may serve as triage centres for storage, translation re-initiation or degradation of specific mRNAs. However, the mechanism involved in the modulation of their assembly/disassembly is unclear. Here we report that Wnt signalling negatively regulates SG assembly through Dishevelled (Dvl), a cytoplasmic Wnt effector. Overexpression of Dvl2, an isoform of Dvl, leads to impairment of SG assembly through a DEP domain dependent mechanism. Intriguingly, the Dvl2 mutant K446M, which corresponds to an analogous mutation in Drosophila Dishevelled DEP domain (dsh1) that results in defective PCP pathway, fails to antagonize SG assembly. Furthermore, we show that Dvl2 exerts the antagonistic effect on SG assembly through a mechanism involving Rac1-mediated inhibition of RhoA. Dvl2 interacts with G3BP, a downstream component of Ras signalling involved in SG assembly, and functional analysis suggests a model wherein the Dvl-Rac1-RhoA axis regulates G3BP's SG-nucleating activity. Collectively, these results define an antagonistic effect of Wnt signalling on SG assembly, and reveal a novel role for Wnt/Dvl pathway in the modulation of mRNA functions. PMID:23213403

  15. Genetic analysis of disheveled 2 and disheveled 3 in human neural tube defects.

    PubMed

    De Marco, Patrizia; Merello, Elisa; Consales, Alessandro; Piatelli, Gianluca; Cama, Armando; Kibar, Zoha; Capra, Valeria

    2013-03-01

    Neural tube defects are severe malformations affecting 1/1,000 live births. The planar cell polarity pathway controls the neural tube closure and has been implicated in the pathogenesis of neural tube defects both in animal models and human cohorts. In mouse disruption of Dvl2 alone (Dvl2 (-/-)) or Dvl2 and Dvl3 (Dvl2 (-/-); Dvl3 (+/-), Dvl2 (+/-); Dvl3 (-/-)) results in incomplete neurulation, suggesting a role for Disheveled in neural tube closure. Disheveled is a multifunctional protein that is involved in both the canonical Wnt signaling and the noncanonical planar cell polarity pathway. In this study, we analyzed the role of the human orthologs DVL2 and DVL3 in a cohort of 473 patients with neural tube defects. Rare variants were genotyped in 639 ethnically matched controls. We identified seven rare missense mutations that were absent in all controls analyzed. Two of these mutations, p.Tyr667Cys and p.Ala53Val, identified in DVL2 were predicted to be detrimental in silico. Significantly, a 1-bp insertion (c.1801_1802insG) in exon 15 of DVL2 predicted to lead to the truncation of the protein was identified in a patient with a complex form of caudal agenesis. In summary, we demonstrate a possible role for rare variants in DVL2 gene as risk factors for neural tube defects.

  16. Segment polarity gene expression in a myriapod reveals conserved and diverged aspects of early head patterning in arthropods.

    PubMed

    Janssen, Ralf

    2012-09-01

    Arthropods show two kinds of developmental mode. In the so-called long germ developmental mode (as exemplified by the fly Drosophila), all segments are formed almost simultaneously from a preexisting field of cells. In contrast, in the so-called short germ developmental mode (as exemplified by the vast majority of arthropods), only the anterior segments are patterned similarly as in Drosophila, and posterior segments are added in a single or double segmental periodicity from a posterior segment addition zone (SAZ). The addition of segments from the SAZ is controlled by dynamic waves of gene activity. Recent studies on a spider have revealed that a similar dynamic process, involving expression of the segment polarity gene (SPG) hedgehog (hh), is involved in the formation of the anterior head segments. The present study shows that in the myriapod Glomeris marginata the early expression of hh is also in a broad anterior domain, but this domain corresponds only to the ocular and antennal segment. It does not, like in spiders, represent expression in the posterior adjacent segment. In contrast, the anterior hh pattern is conserved in Glomeris and insects. All investigated myriapod SPGs and associated factors are expressed with delay in the premandibular (tritocerebral) segment. This delay is exclusively found in insects and myriapods, but not in chelicerates, crustaceans and onychophorans. Therefore, it may represent a synapomorphy uniting insects and myriapods (Atelocerata hypothesis), contradicting the leading opinion that suggests a sister relationship of crustaceans and insects (Pancrustacea hypothesis). In Glomeris embryos, the SPG engrailed is first expressed in the mandibular segment. This feature is conserved in representatives of all arthropod classes suggesting that the mandibular segment may have a special function in anterior patterning.

  17. Structure-function dissection of the frizzled receptor in Drosophila melanogaster suggests different mechanisms of action in planar polarity and canonical Wnt signaling.

    PubMed

    Strutt, David; Madder, Daisy; Chaudhary, Varun; Artymiuk, Peter J

    2012-12-01

    Members of the Frizzled family of sevenpass transmembrane receptors signal via the canonical Wnt pathway and also via noncanonical pathways of which the best characterized is the planar polarity pathway. Activation of both canonical and planar polarity signaling requires interaction between Frizzled receptors and cytoplasmic proteins of the Dishevelled family; however, there has been some dispute regarding whether the Frizzled-Dishevelled interactions are the same in both cases. Studies looking at mutated forms of Dishevelled suggested that stable recruitment of Dishevelled to membranes by Frizzled was required only for planar polarity activity, implying that qualitatively different Frizzled-Dishevelled interactions underlie canonical signaling. Conversely, studies looking at the sequence requirements of Frizzled receptors in the fruit fly Drosophila melanogaster for canonical and planar polarity signaling have concluded that there is most likely a common mechanism of action. To understand better Frizzled receptor function, we have carried out a large-scale mutagenesis in Drosophila to isolate novel mutations in frizzled that affect planar polarity activity and have identified a group of missense mutations in cytosolic-facing regions of the Frizzled receptor that block Dishevelled recruitment. Interestingly, although some of these affect both planar polarity and canonical activity, as previously reported for similar lesions, we find a subset that affect only planar polarity activity. These results support the view that qualitatively different Frizzled-Dishevelled interactions underlie planar polarity and canonical Wnt signaling.

  18. Asymmetric colocalization of Flamingo, a seven-pass transmembrane cadherin, and Dishevelled in planar cell polarization.

    PubMed

    Shimada, Y; Usui, T; Yanagawa, S; Takeichi, M; Uemura, T

    2001-06-05

    The Drosophila wing provides an appropriate model system for studying genetic programming of planar cell polarity (PCP) [1-4]. Each wing cell respects the proximodistal (PD) axis; i.e., it localizes an assembly of actin bundles to its distalmost vertex and produces a single prehair. This PD polarization requires the redistribution of Flamingo (Fmi), a seven-pass transmembrane cadherin, to proximal/distal cell boundaries; otherwise, the cell mislocalizes the prehair [5]. Achievement of the biased Fmi pattern depends on two upstream components in the PCP signaling pathway: Frizzled (Fz), a receptor for a hypothetical polarity signal, and an intracellular protein, Dishevelled (Dsh) [6-8]. Here, we visualized endogenous Dsh in the developing wing. A portion of Dsh colocalized with Fmi, and the distributions of both proteins were interdependent. Furthermore, Fz controlled the association of Dsh with cell boundaries, which association was correlated with the presence of hyperphosphorylated forms of Dsh. Our results, together with a recent study on Fz distribution [9], support the possibility that Fz, Dsh, and Fmi constitute a signaling complex and that its restricted localization directs cytoskeletal reorganization only at the distal cell edge.

  19. Dishevelled genes mediate a conserved mammalian PCP pathway to regulate convergent extension during neurulation

    PubMed Central

    Wang, Jianbo; Hamblet, Natasha S.; Mark, Sharayne; Dickinson, Mary E.; Brinkman, Brendan C.; Segil, Neil; Fraser, Scott E.; Chen, Ping; Wallingford, John B.; Wynshaw-Boris, Anthony

    2014-01-01

    The planar cell polarity (PCP) pathway is conserved throughout evolution, but it mediates distinct developmental processes. In Drosophila, members of the PCP pathway localize in a polarized fashion to specify the cellular polarity within the plane of the epithelium, perpendicular to the apicobasal axis of the cell. In Xenopus and zebrafish, several homologs of the components of the fly PCP pathway control convergent extension. We have shown previously that mammalian PCP homologs regulate both cell polarity and polarized extension in the cochlea in the mouse. Here we show, using mice with null mutations in two mammalian Dishevelled homologs, Dvl1 and Dvl2, that during neurulation a homologous mammalian PCP pathway regulates concomitant lengthening and narrowing of the neural plate, a morphogenetic process defined as convergent extension. Dvl2 genetically interacts with Loop-tail, a point mutation in the mammalian PCP gene Vangl2, during neurulation. By generating Dvl2 BAC (bacterial artificial chromosome) transgenes and introducing different domain deletions and a point mutation identical to the dsh1 allele in fly, we further demonstrated a high degree of conservation between Dvl function in mammalian convergent extension and the PCP pathway in fly. In the neuroepithelium of neurulating embryos, Dvl2 shows DEP domain-dependent membrane localization, a pre-requisite for its involvement in convergent extension. Intriguing, the Loop-tail mutation that disrupts both convergent extension in the neuroepithelium and PCP in the cochlea does not disrupt Dvl2 membrane distribution in the neuroepithelium, in contrast to its drastic effect on Dvl2 localization in the cochlea. These results are discussed in light of recent models on PCP and convergent extension. PMID:16571627

  20. Gpr125 modulates Dishevelled distribution and planar cell polarity signaling.

    PubMed

    Li, Xin; Roszko, Isabelle; Sepich, Diane S; Ni, Mingwei; Hamm, Heidi E; Marlow, Florence L; Solnica-Krezel, Lilianna

    2013-07-01

    During vertebrate gastrulation, Wnt/planar cell polarity (PCP) signaling orchestrates polarized cell behaviors underlying convergence and extension (C&E) movements to narrow embryonic tissues mediolaterally and lengthen them anteroposteriorly. Here, we have identified Gpr125, an adhesion G protein-coupled receptor, as a novel modulator of the Wnt/PCP signaling system. Excess Gpr125 impaired C&E movements and the underlying cell and molecular polarities. Reduced Gpr125 function exacerbated the C&E and facial branchiomotor neuron (FBMN) migration defects of embryos with reduced Wnt/PCP signaling. At the molecular level, Gpr125 recruited Dishevelled to the cell membrane, a prerequisite for Wnt/PCP activation. Moreover, Gpr125 and Dvl mutually clustered one another to form discrete membrane subdomains, and the Gpr125 intracellular domain directly interacted with Dvl in pull-down assays. Intriguingly, Dvl and Gpr125 were able to recruit a subset of PCP components into membrane subdomains, suggesting that Gpr125 may modulate the composition of Wnt/PCP membrane complexes. Our study reveals a role for Gpr125 in PCP-mediated processes and provides mechanistic insight into Wnt/PCP signaling.

  1. Gpr125 modulates Dishevelled distribution and planar cell polarity signaling

    PubMed Central

    Li, Xin; Roszko, Isabelle; Sepich, Diane S.; Ni, Mingwei; Hamm, Heidi E.; Marlow, Florence L.; Solnica-Krezel, Lilianna

    2013-01-01

    During vertebrate gastrulation, Wnt/planar cell polarity (PCP) signaling orchestrates polarized cell behaviors underlying convergence and extension (C&E) movements to narrow embryonic tissues mediolaterally and lengthen them anteroposteriorly. Here, we have identified Gpr125, an adhesion G protein-coupled receptor, as a novel modulator of the Wnt/PCP signaling system. Excess Gpr125 impaired C&E movements and the underlying cell and molecular polarities. Reduced Gpr125 function exacerbated the C&E and facial branchiomotor neuron (FBMN) migration defects of embryos with reduced Wnt/PCP signaling. At the molecular level, Gpr125 recruited Dishevelled to the cell membrane, a prerequisite for Wnt/PCP activation. Moreover, Gpr125 and Dvl mutually clustered one another to form discrete membrane subdomains, and the Gpr125 intracellular domain directly interacted with Dvl in pull-down assays. Intriguingly, Dvl and Gpr125 were able to recruit a subset of PCP components into membrane subdomains, suggesting that Gpr125 may modulate the composition of Wnt/PCP membrane complexes. Our study reveals a role for Gpr125 in PCP-mediated processes and provides mechanistic insight into Wnt/PCP signaling. PMID:23821037

  2. The Dishevelled Protein Family: Still Rather a Mystery After Over 20 Years of Molecular Studies

    PubMed Central

    Mlodzik, Marek

    2016-01-01

    Dishevelled (Dsh) is a key component of Wnt-signaling pathways and possibly also has other functional requirements. Dsh appears to be a key factor to interpret Wnt signals coming via the Wnt-receptor family, the Frizzled proteins, from the plasma membrane and route them into the correct intracellular pathways. However, how Dsh is regulated to relay signal flow to specific and distinct cellular responses upon interaction with the same Wnt-receptor family remains very poorly understood. PMID:26969973

  3. Purified Wnt-5a increases differentiation of midbrain dopaminergic cells and dishevelled phosphorylation.

    PubMed

    Schulte, Gunnar; Bryja, Vítezslav; Rawal, Nina; Castelo-Branco, Goncalo; Sousa, Kyle M; Arenas, Ernest

    2005-03-01

    The Wnt family of lipoproteins regulates several aspects of the development of the nervous system. Recently, we reported that Wnt-3a enhances the proliferation of midbrain dopaminergic precursors and that Wnt-5a promotes their differentiation into dopaminergic neurones. Here we report the purification of hemagglutinin-tagged Wnt-5a using a three-step purification method similar to that previously described for Wnt-3a. Haemagglutinin-tagged Wnt-5a was biologically active and induced the differentiation of immature primary midbrain precursors into tyrosine hydroxylase-positive dopaminergic neurones. Using a substantia nigra-derived dopaminergic cell line (SN4741), we found that Wnt-5a, unlike Wnt-3a, did not promote beta-catenin phosphorylation or stabilization. However, both Wnt-5a and Wnt-3a activated dishevelled, as assessed by a phosphorylation-dependent mobility shift. Moreover, the activity of Wnt-5a on dishevelled was blocked by pre-treatment with acyl protein thioesterase-1, indicating that palmitoylation of Wnt-5a is necessary for its function. Thus, our results suggest that Wnt-3a and Wnt-5a, respectively, activate canonical and non-canonical Wnt signalling pathways in ventral midbrain dopaminergic cells. Furthermore, we identify dishevelled as a key player in transducing both Wnt canonical and non-canonical signals in dopaminergic cells.

  4. Planar Cell Polarity Effector Fritz Interacts with Dishevelled and Has Multiple Functions in Regulating PCP.

    PubMed

    Wang, Ying; Naturale, Victor F; Adler, Paul N

    2017-03-03

    The Planar cell Polarity Effector (PPE) genes inturned, fuzzy and fritz are downstream components in the frizzled/starry night signaling pathway, and their function is instructed by upstream Planar Cell Polarity (PCP) core genes such as frizzled and disheveled PPE proteins accumulate asymmetrically in wing cells and function in a protein complex mediated by direct interactions between In and Frtz and In and Fy. How the PCP proteins instruct the accumulation of PPE protein is unknown. We found a likely direct interaction between Dishevelled and Fritz and Dishevelled and Fuzzy that could play a role in this. We previously found that mild over expression of frtz rescued a weak in allele. To determine if this was due to extra Frtz stabilizing mutant In or due to Frtz being able to bypass the need for In we generate a precise deletion of the inturned gene (in(PD) ). We found that mild overexpression of Fritz partially rescued in(PD) , indicating that fritz has In independent activity in PCP. Previous studies of PPE proteins used fixed tissues, and did not provide any insights into the dynamic properties of PPE proteins. We used CRISPR/Cas9 genome editing technology to edit the fritz gene to add a green fluorescent protein tag. fritz(m)(NeonGreen) provides complete rescue activity and works well for in vivo imaging. Our data showed that Fritz is very dynamic in epidermal cells and preferentially distributed to discrete membrane subdomains ("puncta"). Surprisingly, we found it in stripes in developing bristles.

  5. Essential role of the Dishevelled DEP domain in a Wnt-dependent human-cell-based complementation assay

    PubMed Central

    Gammons, Melissa V.; Rutherford, Trevor J.; Steinhart, Zachary; Angers, Stephane

    2016-01-01

    ABSTRACT Dishevelled (DVL) assembles Wnt signalosomes through dynamic head-to-tail polymerisation by means of its DIX domain. It thus transduces Wnt signals to cytoplasmic effectors including β-catenin, to control cell fates during normal development, tissue homeostasis and also in cancer. To date, most functional studies of Dishevelled relied on its Wnt-independent signalling activity resulting from overexpression, which is sufficient to trigger polymerisation, bypassing the requirement for Wnt signals. Here, we generate a human cell line devoid of endogenous Dishevelled (DVL1– DVL3), which lacks Wnt signal transduction to β-catenin. However, Wnt responses can be restored by DVL2 stably re-expressed at near-endogenous levels. Using this assay to test mutant DVL2, we show that its DEP domain is essential, whereas its PDZ domain is dispensable, for signalling to β-catenin. Our results imply two mutually exclusive functions of the DEP domain in Wnt signal transduction – binding to Frizzled to recruit Dishevelled to the receptor complex, and dimerising to cross-link DIX domain polymers for signalosome assembly. Our assay avoids the caveats associated with overexpressing Dishevelled, and provides a powerful tool for rigorous functional tests of this pivotal human signalling protein. PMID:27744318

  6. The Drosophila neurogenin Tap functionally interacts with the Wnt-PCP pathway to regulate neuronal extension and guidance

    PubMed Central

    Yuan, Liqun; Hu, Shu; Okray, Zeynep; Ren, Xi; De Geest, Natalie; Claeys, Annelies; Yan, Jiekun; Bellefroid, Eric; Quan, Xiao-Jiang

    2016-01-01

    The neurogenin (Ngn) transcription factors control early neurogenesis and neurite outgrowth in mammalian cortex. In contrast to their proneural activity, their function in neurite growth is poorly understood. Drosophila has a single predicted Ngn homolog, Tap, of unknown function. Here we show that Tap is not a proneural protein in Drosophila but is required for proper axonal growth and guidance of neurons of the mushroom body, a neuropile required for associative learning and memory. Genetic and expression analyses suggest that Tap inhibits excessive axonal growth by fine regulation of the levels of the Wnt signaling adaptor protein Dishevelled. PMID:27385016

  7. Planar Cell Polarity Effector Fritz Interacts with Dishevelled and Has Multiple Functions in Regulating PCP

    PubMed Central

    Wang, Ying; Naturale, Victor F.; Adler, Paul N.

    2017-01-01

    The Planar cell Polarity Effector (PPE) genes inturned, fuzzy, and fritz are downstream components in the frizzled/starry night signaling pathway, and their function is instructed by upstream Planar Cell Polarity (PCP) core genes such as frizzled and dishevelled. PPE proteins accumulate asymmetrically in wing cells and function in a protein complex mediated by direct interactions between In and Frtz and In and Fy. How the PCP proteins instruct the accumulation of PPE protein is unknown. We found a likely direct interaction between Dishevelled and Fritz and Dishevelled and Fuzzy that could play a role in this. We previously found that mild overexpression of frtz rescued a weak in allele. To determine if this was due to extra Frtz stabilizing mutant In or due to Frtz being able to bypass the need for In we generate a precise deletion of the inturned gene (inPD). We found that mild overexpression of Fritz partially rescued inPD, indicating that fritz has In independent activity in PCP. Previous studies of PPE proteins used fixed tissues, and did not provide any insights into the dynamic properties of PPE proteins. We used CRISPR/Cas9 genome editing technology to edit the fritz gene to add a green fluorescent protein tag. fritzmNeonGreen provides complete rescue activity and works well for in vivo imaging. Our data showed that Fritz is very dynamic in epidermal cells and preferentially distributed to discrete membrane subdomains (“puncta”). Surprisingly, we found it in stripes in developing bristles. PMID:28258110

  8. Expression of segment polarity genes in brachiopods supports a non-segmental ancestral role of engrailed for bilaterians

    PubMed Central

    Vellutini, Bruno C.; Hejnol, Andreas

    2016-01-01

    The diverse and complex developmental mechanisms of segmentation have been more thoroughly studied in arthropods, vertebrates and annelids—distantly related animals considered to be segmented. Far less is known about the role of “segmentation genes” in organisms that lack a segmented body. Here we investigate the expression of the arthropod segment polarity genes engrailed, wnt1 and hedgehog in the development of brachiopods—marine invertebrates without a subdivided trunk but closely related to the segmented annelids. We found that a stripe of engrailed expression demarcates the ectodermal boundary that delimits the anterior region of Terebratalia transversa and Novocrania anomala embryos. In T. transversa, this engrailed domain is abutted by a stripe of wnt1 expression in a pattern similar to the parasegment boundaries of insects—except for the expression of hedgehog, which is restricted to endodermal tissues of the brachiopod embryos. We found that pax6 and pax2/5/8, putative regulators of engrailed, also demarcate the anterior boundary in the two species, indicating these genes might be involved in the anterior patterning of brachiopod larvae. In a comparative phylogenetic context, these findings suggest that bilaterians might share an ancestral, non-segmental domain of engrailed expression during early embryogenesis. PMID:27561213

  9. Dishevelled is a NEK2 kinase substrate controlling dynamics of centrosomal linker proteins

    PubMed Central

    Cervenka, Igor; Valnohova, Jana; Bernatik, Ondrej; Harnos, Jakub; Radsetoulal, Matej; Sedova, Katerina; Hanakova, Katerina; Potesil, David; Sedlackova, Miroslava; Salasova, Alena; Steinhart, Zachary; Angers, Stephane; Schulte, Gunnar; Hampl, Ales; Zdrahal, Zbynek; Bryja, Vitezslav

    2016-01-01

    Dishevelled (DVL) is a key scaffolding protein and a branching point in Wnt signaling pathways. Here, we present conclusive evidence that DVL regulates the centrosomal cycle. We demonstrate that DVL dishevelled and axin (DIX) domain, but not DIX domain-mediated multimerization, is essential for DVL’s centrosomal localization. DVL accumulates during the cell cycle and associates with NIMA-related kinase 2 (NEK2), which is able to phosphorylate DVL at a multitude of residues, as detected by a set of novel phospho-specific antibodies. This creates interfaces for efficient binding to CDK5 regulatory subunit-associated protein 2 (CDK5RAP2) and centrosomal Nek2-associated protein 1 (C-NAP1), two proteins of the centrosomal linker. Displacement of DVL from the centrosome and its release into the cytoplasm on NEK2 phosphorylation is coupled to the removal of linker proteins, an event necessary for centrosomal separation and proper formation of the mitotic spindle. Lack of DVL prevents NEK2-controlled dissolution of loose centrosomal linker and subsequent centrosomal separation. Increased DVL levels, in contrast, sequester centrosomal NEK2 and mimic monopolar spindle defects induced by a dominant negative version of this kinase. Our study thus uncovers molecular crosstalk between centrosome and Wnt signaling. PMID:27486244

  10. Conformational change of Dishevelled plays a key regulatory role in the Wnt signaling pathways

    PubMed Central

    Lee, Ho-Jin; Shi, De-Li; Zheng, Jie J

    2015-01-01

    The intracellular signaling molecule Dishevelled (Dvl) mediates canonical and non-canonical Wnt signaling via its PDZ domain. Different pathways diverge at this point by a mechanism that remains unclear. Here we show that the peptide-binding pocket of the Dvl PDZ domain can be occupied by Dvl's own highly conserved C-terminus, inducing a closed conformation. In Xenopus, Wnt-regulated convergent extension (CE) is readily affected by Dvl mutants unable to form the closed conformation than by wild-type Dvl. We also demonstrate that while Dvl cooperates with other Wnt pathway elements to activate canonical Wnt signaling, the open conformation of Dvl more effectively activates Jun N-terminal kinase (JNK). These results suggest that together with other players in the Wnt signaling pathway, the conformational change of Dvl regulates Wnt stimulated JNK activity in the non-canonical Wnt signaling. DOI: http://dx.doi.org/10.7554/eLife.08142.001 PMID:26297804

  11. Structural basis of the recognition of the dishevelled DEP domain in the Wnt signaling pathway.

    PubMed

    Wong, H C; Mao, J; Nguyen, J T; Srinivas, S; Zhang, W; Liu, B; Li, L; Wu, D; Zheng, J

    2000-12-01

    The DEP domain of Dishevelled (Dvl) proteins transduces signals to effector proteins downstream of Dvl in the Wnt pathway. Here we report that DEP-containing mutants inhibit Wnt-induced, but not Dvl-induced, activation of the transcription factor Lef-1. This inhibitory effect is weakened by a K434M mutation. Nuclear magnetic resonance spectroscopy revealed that the DEP domain of mouse Dvl1 comprises a three-helix bundle, a beta-hairpin 'arm' and two short beta-strands at the C-terminal region. Lys 434 is located at the tip of the beta-hairpin 'arm'. Based on our findings, we conclude that DEP interacts with regulators upstream of Dvl via a strong electric dipole on the molecule's surface created by Lys 434, Asp 445 and Asp 448; the electric dipole and the putative membrane binding site are at two different locations.

  12. Overexpression of Dishevelled-2 contributes to proliferation and migration of human esophageal squamous cell carcinoma.

    PubMed

    Zhou, Guoren; Ye, Jinjun; Sun, Lei; Zhang, Zhi; Feng, Jifeng

    2016-06-01

    Dishevelled-2 (Dvl2) was associated with tumor cell proliferation and migration. We aimed to examine the mechanism of Dvl2 in esophageal squamous cell carcinoma (ESCC). Dvl2 was overexpressed in human ESCC tissues and cell lines ECA109 and TE1 cells. CCK-8 and colony formation assay was performed to evaluate the proliferation in ECA109 cells transfected with Dvl2-shRNA. Wound-healing assay and transwell assay were used to examine the activities of migration and invasion in Dvl2-silenced ESCC cells. Knockdown of Dvl2 significantly reduced ECA109 cell proliferation and migration. Moreover, we demonstrated that the proliferation and migration ability of Dvl2 might through the activation of Wnt pathway by targeting the Cyclin D1 and MMP-9. We came to the conclusion that the proliferation and migration effects of Dvl2 might contribute to malignant development of human ESCC.

  13. Murine Dishevelled 3 Functions in Redundant Pathways with Dishevelled 1 and 2 in Normal Cardiac Outflow Tract, Cochlea, and Neural Tube Development

    PubMed Central

    Etheridge, S. Leah; Ray, Saugata; Li, Shuangding; Hamblet, Natasha S.; Lijam, Nardos; Tsang, Michael; Greer, Joy; Kardos, Natalie; Wang, Jianbo; Sussman, Daniel J.; Chen, Ping; Wynshaw-Boris, Anthony

    2008-01-01

    Dishevelled (Dvl) proteins are important signaling components of both the canonical β-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3 −/− mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3 −/− and LtapLp/+ mutants, Dvl3 +/−;LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant. PMID:19008950

  14. Modulation of Dishevelled and Vangl2 by all-trans-retinoic acid in the developing mouse central nervous system and its relationship to teratogenesis.

    PubMed

    Zhang, Yanping; Liu, Kai; Gao, Yingmao; Li, Shaoling

    2007-09-01

    The response to exposure to all-trans-retinoic acid (RA) during embryogenesis varies from physiologic to severe teratogenic effects and is dependent upon the dose and the stage of development in all species. Vangl2 and Dishevelled genes play key roles in establishing planar cell polarity and regulating convergent extension movements during the neurula period. The effects of RA-mediated teratogenesis might be due to its misregulation of Vangl2 and Dishevelled genes. The aim of this study is to monitor the modulation of Vangl2 and Dishevelled in Kunming mouse embryos following maternal treatment with a single oral dose of 30 mg/(kg body weight) of RA during the neurula period. Exposure of 7.75 d embryos to RA induced characteristic morphological changes. The most obvious external effect was the failure of neural tube closure in the midbrain and forebrain regions in 10 d embryos, resulting in exencephaly in later embryos. RA treatment also led to a pronounced decrease of Vangl2 mRNA at 4 and 18 h and a pronounced increase at 66 h after maternal treatment, as detected by reverse transcription-polymerase chain reaction. Western blot analysis showed a marked decrease of Vangl2 protein at 18 and 42 h and a marked increase at 66 and 90 h after maternal treatment. Dishevelled1/2/3 mRNA was significantly down-regulated at 4 and 18 h and up-regulated at 42 h in the fetus after RA treatment, except for an up-regulation of Dishevelled3 at 66 h. The Dishevelled2 mRNA and its protein matched each other. These results hinted that Vangl2 and Dishevelled genes might take part in RA teratogenesis of mouse embryos.

  15. Dishevelled is essential for neural connectivity and planar cell polarity in planarians.

    PubMed

    Almuedo-Castillo, Maria; Saló, Emili; Adell, Teresa

    2011-02-15

    The Wingless/Integrated (Wnt) signaling pathway controls multiple events during development and homeostasis. It comprises multiple branches, mainly classified according to their dependence on β-catenin activation. The Wnt/β-catenin branch is essential for the establishment of the embryonic anteroposterior (AP) body axis throughout the phylogenetic tree. It is also required for AP axis establishment during planarian regeneration. Wnt/β-catenin-independent signaling encompasses several different pathways, of which the most extensively studied is the planar cell polarity (PCP) pathway, which is responsible for planar polarization of cell structures within an epithelial sheet. Dishevelled (Dvl) is the hub of Wnt signaling because it regulates and channels the Wnt signal into every branch. Here, we analyze the role of Schmidtea mediterranea Dvl homologs (Smed-dvl-1 and Smed-dvl-2) using gene silencing. We demonstrate that in addition to a role in AP axis specification, planarian Dvls are involved in at least two different β-catenin-independent processes. First, they are essential for neural connectivity through Smed-wnt5 signaling. Second, Smed-dvl-2, together with the S. mediterranea homologs of Van-Gogh (Vang) and Diversin (Div), is required for apical positioning of the basal bodies of epithelial cells. These data represent evidence not only of the function of the PCP network in lophotrocozoans but of the involvement of the PCP core elements Vang and Div in apical positioning of the cilia.

  16. Loss of Dishevelleds disrupts planar polarity in ependymal motile cilia and results in hydrocephalus.

    PubMed

    Ohata, Shinya; Nakatani, Jin; Herranz-Pérez, Vicente; Cheng, JrGang; Belinson, Haim; Inubushi, Toshiro; Snider, William D; García-Verdugo, Jose Manuel; Wynshaw-Boris, Anthony; Alvarez-Buylla, Arturo

    2014-08-06

    Defects in ependymal (E) cells, which line the ventricle and generate cerebrospinal fluid flow through ciliary beating, can cause hydrocephalus. Dishevelled genes (Dvls) are essential for Wnt signaling, and Dvl2 has been shown to localize to the rootlet of motile cilia. Using the hGFAP-Cre;Dvl1(-/-);2(flox/flox);3(+/-) mouse, we show that compound genetic ablation of Dvls causes hydrocephalus. In hGFAP-Cre;Dvl1(-/-);2(flox/flox);3(+/-) mutants, E cells differentiated normally, but the intracellular and intercellular rotational alignments of ependymal motile cilia were disrupted. As a consequence, the fluid flow generated by the hGFAP-Cre;Dvl1(-/-);2(flox/flox);3(+/-) E cells was significantly slower than that observed in control mice. Dvls were also required for the proper positioning of motile cilia on the apical surface. Tamoxifen-induced conditional removal of Dvls in adult mice also resulted in defects in intracellular rotational alignment and positioning of ependymal motile cilia. These results suggest that Dvls are continuously required for E cell planar polarity and may prevent hydrocephalus.

  17. Loss of Dishevelleds disrupts planar polarity in ependymal motile cilia and results in hydrocephalus

    PubMed Central

    Ohata, Shinya; Nakatani, Jin; Herranz-Pérez, Vicente; Cheng, JrGang; Belinson, Haim; Inubushi, Toshiro; Snider, William D.; García-Verdugo, Jose Manuel; Wynshaw-Boris, Anthony; Álvarez-Buylla, Arturo

    2014-01-01

    SUMMARY Defects in ependymal (E) cells, which line the ventricle and generate cerebrospinal fluid flow through ciliary beating, can cause hydrocephalus. Dishevelled genes (Dvls) are essential for Wnt signaling and Dvl2 has been shown to localize to the rootlet of motile cilia. Using the hGFAP-Cre;Dvl1−/−;2flox/flox;3+/− mouse, we show that compound genetic ablation of Dvls causes hydrocephalus. In hGFAP-Cre;Dvl1−/−;2flox/flox;3+/− mutants, E cells differentiated normally, but the intracellular and intercellular rotational alignments of ependymal motile cilia were disrupted. As a consequence, the fluid flow generated by the hGFAP-Cre;Dvl1−/−;2flox/flox;3+/− E cells was significantly slower than that observed in control mice. Dvls were also required for the proper positioning of motile cilia on the apical surface. Tamoxifen-induced conditional removal of Dvls in adult mice also resulted in defects in intracellular rotational alignment and positioning of ependymal motile cilia. These results suggest that Dvls are continuously required for E cell planar polarity and may prevent hydrocephalus. PMID:25043421

  18. Epsin is required for Dishevelled stability and Wnt signalling activation in colon cancer development.

    PubMed

    Chang, Baojun; Tessneer, Kandice L; McManus, John; Liu, Xiaolei; Hahn, Scott; Pasula, Satish; Wu, Hao; Song, Hoogeun; Chen, Yiyuan; Cai, Xiaofeng; Dong, Yunzhou; Brophy, Megan L; Rahman, Ruby; Ma, Jian-Xing; Xia, Lijun; Chen, Hong

    2015-03-16

    Uncontrolled canonical Wnt signalling supports colon epithelial tumour expansion and malignant transformation. Understanding the regulatory mechanisms involved is crucial for elucidating the pathogenesis of and will provide new therapeutic targets for colon cancer. Epsins are ubiquitin-binding adaptor proteins upregulated in several human cancers; however, the involvement of epsins in colon cancer is unknown. Here we show that loss of intestinal epithelial epsins protects against colon cancer by significantly reducing the stability of the crucial Wnt signalling effector, dishevelled (Dvl2), and impairing Wnt signalling. Consistently, epsins and Dvl2 are correspondingly upregulated in colon cancer. Mechanistically, epsin binds Dvl2 via its epsin N-terminal homology domain and ubiquitin-interacting motifs and prohibits Dvl2 polyubiquitination and degradation. Our findings reveal an unconventional role for epsins in stabilizing Dvl2 and potentiating Wnt signalling in colon cancer cells to ensure robust colon cancer progression. The pro-carcinogenic role of Epsins suggests that they are potential therapeutic targets to combat colon cancer.

  19. Controversies surrounding segments and parasegments in onychophora: insights from the expression patterns of four "segment polarity genes" in the peripatopsid Euperipatoides rowelli.

    PubMed

    Franke, Franziska Anni; Mayer, Georg

    2014-01-01

    Arthropods typically show two types of segmentation: the embryonic parasegments and the adult segments that lie out of register with each other. Such a dual nature of body segmentation has not been described from Onychophora, one of the closest arthropod relatives. Hence, it is unclear whether onychophorans have segments, parasegments, or both, and which of these features was present in the last common ancestor of Onychophora and Arthropoda. To address this issue, we analysed the expression patterns of the "segment polarity genes" engrailed, cubitus interruptus, wingless and hedgehog in embryos of the onychophoran Euperipatoides rowelli. Our data revealed that these genes are expressed in repeated sets with a specific anterior-to-posterior order along the body in embryos of E. rowelli. In contrast to arthropods, the expression occurs after the segmental boundaries have formed. Moreover, the initial segmental furrow retains its position within the engrailed domain throughout development, whereas no new furrow is formed posterior to this domain. This suggests that no re-segmentation of the embryo occurs in E. rowelli. Irrespective of whether or not there is a morphological or genetic manifestation of parasegments in Onychophora, our data clearly show that parasegments, even if present, cannot be regarded as the initial metameric units of the onychophoran embryo, because the expression of key genes that define the parasegmental boundaries in arthropods occurs after the segmental boundaries have formed. This is in contrast to arthropods, in which parasegments rather than segments are the initial metameric units of the embryo. Our data further revealed that the expression patterns of "segment polarity genes" correspond to organogenesis rather than segment formation. This is in line with the concept of segmentation as a result of concerted evolution of individual periodic structures rather than with the interpretation of 'segments' as holistic units.

  20. Controversies Surrounding Segments and Parasegments in Onychophora: Insights from the Expression Patterns of Four “Segment Polarity Genes” in the Peripatopsid Euperipatoides rowelli

    PubMed Central

    Franke, Franziska Anni; Mayer, Georg

    2014-01-01

    Arthropods typically show two types of segmentation: the embryonic parasegments and the adult segments that lie out of register with each other. Such a dual nature of body segmentation has not been described from Onychophora, one of the closest arthropod relatives. Hence, it is unclear whether onychophorans have segments, parasegments, or both, and which of these features was present in the last common ancestor of Onychophora and Arthropoda. To address this issue, we analysed the expression patterns of the “segment polarity genes” engrailed, cubitus interruptus, wingless and hedgehog in embryos of the onychophoran Euperipatoides rowelli. Our data revealed that these genes are expressed in repeated sets with a specific anterior-to-posterior order along the body in embryos of E. rowelli. In contrast to arthropods, the expression occurs after the segmental boundaries have formed. Moreover, the initial segmental furrow retains its position within the engrailed domain throughout development, whereas no new furrow is formed posterior to this domain. This suggests that no re-segmentation of the embryo occurs in E. rowelli. Irrespective of whether or not there is a morphological or genetic manifestation of parasegments in Onychophora, our data clearly show that parasegments, even if present, cannot be regarded as the initial metameric units of the onychophoran embryo, because the expression of key genes that define the parasegmental boundaries in arthropods occurs after the segmental boundaries have formed. This is in contrast to arthropods, in which parasegments rather than segments are the initial metameric units of the embryo. Our data further revealed that the expression patterns of “segment polarity genes” correspond to organogenesis rather than segment formation. This is in line with the concept of segmentation as a result of concerted evolution of individual periodic structures rather than with the interpretation of ‘segments’ as holistic units. PMID

  1. Crystal structure of the PDZ domain of mouse Dishevelled 1 and its interaction with CXXC5.

    PubMed

    Lee, Inhwan; Choi, Sooho; Yun, Ji-Hye; Seo, Seolhwa; Choi, Sehee; Choi, Kang-Yell; Lee, Weontae

    2016-12-05

    Dishevelled (Dvl) plays a crucial role in Wnt signaling by interacting with membrane-bound receptors and downstream molecules through its PDZ domain. CXXC5 is one of the key molecules that interacts with Dvl and negatively regulates the Wnt/β-catenin pathway in osteoblast differentiation. Recently, the Dvl-CXXC5 interaction has been identified as an excellent target for osteoporosis treatment. Therefore, it is desirable to have detailed structural information for the Dvl-CXXC5 interaction. Although solution structures of the Dvl1 PDZ domain have been reported, a high-resolution crystal structure would provide detailed sidechain information that is essential for drug development. Here, we determined the first crystal structure of the Dvl-1 PDZ domain at a resolution of 1.76 Å, and compared it with its previously reported solution structure. The Dvl1 PDZ domain crystal belonged to the space group H32 with unit-cell parameters a = b = 72.837, c = 120.616, α = ß = 90.00, γ = 120.00. The crystal structure of Dvl1 PDZ shared its topology with the previously reported structure determined by nuclear magnetic resonance (NMR); however, the crystal structure was quite different from the solution structure in both the secondary structural region and the ligand-binding pocket. Molecular modeling based on NMR and X-ray crystallographic data yielded detailed information about the Dvl1/CXXC5 interaction, which will be useful for designing inhibitors.

  2. Mutations that alter the timing and pattern of cubitus interruptus gene expression in Drosophila melanogaster

    SciTech Connect

    Slusarski, D.C.; Motzny, C.K.; Holmgren, R.

    1995-01-01

    The cubitus interruptus (ci) gene is a member of the Drosophila segment polarity gene family and encodes a protein with a zinc finger domain homologous to the vertebrate Gli genes and the nematode tra-1 gene. Three classes of existing mutations in the ci locus alter the regulation of ci expression and can be used to examine ci function during development. The first class of ci mutations causes interruptions in wing veins four and five due to inappropriate expression of the ci product in the posterior compartment of imaginal discs. The second class of mutations eliminates ci protein early in embryogenesis and causes the deletion of structures that are derived from the region including and adjacent to the engrailed expressing cells. The third class of mutations eliminates ci protein later in embryogenesis and blocks the formation of the ventral naked cuticle. The loss of ci expression at these two different stages in embryonic development correlates with the subsequent elimination of wingless expression. Adults heterozygous for the unique ci{sup Ce} mutation have deletions between wing veins three and four. A similar wing defect is present in animals mutant for the segment polarity gene fused that encodes a putative serine/threonine kinase. In ci{sup Ce}/+ and fused mutants, the deletions between wing veins three and four correlate with increased ci protein levels in the anterior compartment. Thus, proper regulation of both the ci mRNA and protein appears to be critical for normal Drosophila development. 47 refs., 9 figs., 1 tab.

  3. Deciphering the onychophoran 'segmentation gene cascade': Gene expression reveals limited involvement of pair rule gene orthologs in segmentation, but a highly conserved segment polarity gene network.

    PubMed

    Janssen, Ralf; Budd, Graham E

    2013-10-01

    The hallmark of the arthropods is their segmented body, although origin of segmentation, however, is unresolved. In order to shed light on the origin of segmentation we investigated orthologs of pair rule genes (PRGs) and segment polarity genes (SPGs) in a member of the closest related sister-group to the arthropods, the onychophorans. Our gene expression data analysis suggests that most of the onychophoran PRGs do not play a role in segmentation. One possible exception is the even-skipped (eve) gene that is expressed in the posterior end of the onychophoran where new segments are likely patterned, and is also expressed in segmentation-gene typical transverse stripes in at least a number of newly formed segments. Other onychophoran PRGs such as runt (run), hairy/Hes (h/Hes) and odd-skipped (odd) do not appear to have a function in segmentation at all. Onychophoran PRGs that act low in the segmentation gene cascade in insects, however, are potentially involved in segment-patterning. Most obvious is that from the expression of the pairberry (pby) gene ortholog that is expressed in a typical SPG-pattern. Since this result suggested possible conservation of the SPG-network we further investigated SPGs (and associated factors) such as Notum in the onychophoran. We find that the expression patterns of SPGs in arthropods and the onychophoran are highly conserved, suggesting a conserved SPG-network in these two clades, and indeed also in an annelid. This may suggest that the common ancestor of lophotrochozoans and ecdysozoans was already segmented utilising the same SPG-network, or that the SPG-network was recruited independently in annelids and onychophorans/arthropods.

  4. Drosophila spermiogenesis

    PubMed Central

    Fabian, Lacramioara; Brill, Julie A.

    2012-01-01

    Drosophila melanogaster spermatids undergo dramatic morphological changes as they differentiate from small round cells approximately 12 μm in diameter into highly polarized, 1.8 mm long, motile sperm capable of participating in fertilization. During spermiogenesis, syncytial cysts of 64 haploid spermatids undergo synchronous differentiation. Numerous changes occur at a subcellular level, including remodeling of existing organelles (mitochondria, nuclei), formation of new organelles (flagellar axonemes, acrosomes), polarization of elongating cysts and plasma membrane addition. At the end of spermatid morphogenesis, organelles, mitochondrial DNA and cytoplasmic components not needed in mature sperm are stripped away in a caspase-dependent process called individualization that results in formation of individual sperm. Here, we review the stages of Drosophila spermiogenesis and examine our current understanding of the cellular and molecular mechanisms involved in shaping male germ cell-specific organelles and forming mature, fertile sperm. PMID:23087837

  5. Structural Analysis of the Interaction between Dishevelled2 and Clathrin AP-2 Adaptor, A Critical Step in Noncanonical Wnt Signaling

    SciTech Connect

    Yu, Anan; Xing, Yi; Harrison, Stephen C.; Kirchhausen, Tomas

    2010-10-14

    Wnt association with its receptor, Frizzled (Fz), and recruitment by the latter of an adaptor, Dishevelled (Dvl), initiates signaling through at least two distinct pathways (canonical and noncanonical). Endocytosis and compartmentalization help determine the signaling outcome. Our previous work has shown that Dvl2 links at least one Frizzled family member (Fz4) to clathrin-mediated endocytosis by interacting with the {mu}2 subunit of the AP-2 clathrin adaptor, through both a classical endocytic tyrosine motif and a so-called DEP domain. We report here the crystal structure of a chimeric protein that mimics the Dvl2-{mu}2 complex. The DEP domain binds at one end of the elongated, C-terminal domain of {mu}2. This domain:domain interface shows that parts of the {mu}2 surface distinct from the tyrosine-motif site can help recruit specific receptors or adaptors into a clathrin coated pit. Mutation of residues at the DEP-{mu}2 contact or in the tyrosine motif reduce affinity of Dvl2 for {mu}2 and block efficient internalization of Fz4 in response to ligation by Wnt5a. The crystal structure has thus allowed us to identify the specific interaction that leads to Frizzled uptake and to downstream, noncanonical signaling events.

  6. Kif26b controls endothelial cell polarity through the Dishevelled/Daam1-dependent planar cell polarity–signaling pathway

    PubMed Central

    Guillabert-Gourgues, Aude; Jaspard-Vinassa, Beatrice; Bats, Marie-Lise; Sewduth, Raj N.; Franzl, Nathalie; Peghaire, Claire; Jeanningros, Sylvie; Moreau, Catherine; Roux, Etienne; Larrieu-Lahargue, Frederic; Dufourcq, Pascale; Couffinhal, Thierry; Duplàa, Cecile

    2016-01-01

    Angiogenesis involves the coordinated growth and migration of endothelial cells (ECs) toward a proangiogenic signal. The Wnt planar cell polarity (PCP) pathway, through the recruitment of Dishevelled (Dvl) and Dvl-associated activator of morphogenesis (Daam1), has been proposed to regulate cell actin cytoskeleton and microtubule (MT) reorganization for oriented cell migration. Here we report that Kif26b—a kinesin—and Daam1 cooperatively regulate initiation of EC sprouting and directional migration via MT reorganization. First, we find that Kif26b is recruited within the Dvl3/Daam1 complex. Using a three-dimensional in vitro angiogenesis assay, we show that Kif26b and Daam1 depletion impairs tip cell polarization and destabilizes extended vascular processes. Kif26b depletion specifically alters EC directional migration and mislocalized MT organizing center (MTOC)/Golgi and myosin IIB cell rear enrichment. Therefore the cell fails to establish a proper front–rear polarity. Of interest, Kif26b ectopic expression rescues the siDaam1 polarization defect phenotype. Finally, we show that Kif26b functions in MT stabilization, which is indispensable for asymmetrical cell structure reorganization. These data demonstrate that Kif26b, together with Dvl3/Daam1, initiates cell polarity through the control of PCP signaling pathway–dependent activation. PMID:26792835

  7. Kif26b controls endothelial cell polarity through the Dishevelled/Daam1-dependent planar cell polarity-signaling pathway.

    PubMed

    Guillabert-Gourgues, Aude; Jaspard-Vinassa, Beatrice; Bats, Marie-Lise; Sewduth, Raj N; Franzl, Nathalie; Peghaire, Claire; Jeanningros, Sylvie; Moreau, Catherine; Roux, Etienne; Larrieu-Lahargue, Frederic; Dufourcq, Pascale; Couffinhal, Thierry; Duplàa, Cecile

    2016-03-15

    Angiogenesis involves the coordinated growth and migration of endothelial cells (ECs) toward a proangiogenic signal. The Wnt planar cell polarity (PCP) pathway, through the recruitment of Dishevelled (Dvl) and Dvl-associated activator of morphogenesis (Daam1), has been proposed to regulate cell actin cytoskeleton and microtubule (MT) reorganization for oriented cell migration. Here we report that Kif26b--a kinesin--and Daam1 cooperatively regulate initiation of EC sprouting and directional migration via MT reorganization. First, we find that Kif26b is recruited within the Dvl3/Daam1 complex. Using a three-dimensional in vitro angiogenesis assay, we show that Kif26b and Daam1 depletion impairs tip cell polarization and destabilizes extended vascular processes. Kif26b depletion specifically alters EC directional migration and mislocalized MT organizing center (MTOC)/Golgi and myosin IIB cell rear enrichment. Therefore the cell fails to establish a proper front-rear polarity. Of interest, Kif26b ectopic expression rescues the siDaam1 polarization defect phenotype. Finally, we show that Kif26b functions in MT stabilization, which is indispensable for asymmetrical cell structure reorganization. These data demonstrate that Kif26b, together with Dvl3/Daam1, initiates cell polarity through the control of PCP signaling pathway-dependent activation.

  8. Initiation of Wnt signaling: control of Wnt coreceptor Lrp6 phosphorylation/activation via frizzled, dishevelled and axin functions

    PubMed Central

    Zeng, Xin; Huang, He; Tamai, Keiko; Zhang, Xinjun; Harada, Yuko; Yokota, Chika; Almeida, Karla; Wang, Jianbo; Doble, Brad; Woodgett, Jim; Wynshaw-Boris, Anthony; Hsieh, Jen-Chieh; He, Xi

    2016-01-01

    Canonical Wnt/β-catenin signaling has central roles in development and diseases, and is initiated by the action of the frizzled (Fz) receptor, its coreceptor LDL receptor-related protein 6 (Lrp6), and the cytoplasmic dishevelled (Dvl) protein. The functional relationships among Fz, Lrp6 and Dvl have long been enigmatic. We demonstrated previously that Wnt-induced Lrp6 phosphorylation via glycogen synthase kinase 3 (Gsk3) initiates Wnt/β-catenin signaling. Here we show that both Fz and Dvl functions are critical for Wnt-induced Lrp6 phosphorylation through Fz-Lrp6 interaction. We also show that axin, a key scaffolding protein in the Wnt pathway, is required for Lrp6 phosphorylation via its ability to recruit Gsk3, and inhibition of Gsk3 at the plasma membrane blocks Wnt/β-catenin signaling. Our results suggest a model that upon Wnt-induced Fz-Lrp6 complex formation, Fz recruitment of Dvl in turn recruits the axin-Gsk3 complex, thereby promoting Lrp6 phosphorylation to initiate β-catenin signaling. We discuss the dual roles of the axin-Gsk3 complex and signal amplification by Lrp6-axin interaction during Wnt/β-catenin signaling. PMID:18077588

  9. Resolution of structure of PIP5K1A reveals molecular mechanism for its regulation by dimerization and dishevelled

    PubMed Central

    Hu, Jian; Yuan, Qianying; Kang, Xue; Qin, Yuanbo; Li, Lin; Ha, Ya; Wu, Dianqing

    2015-01-01

    Type I phosphatidylinositol phosphate kinase (PIP5K1) phosphorylates the head group of phosphatidylinositol 4-phosphate (PtdIns4P) to generate PtdIns4,5P2, which plays important roles in a wide range of cellular functions including Wnt signalling. However, the lack of its structural information has hindered the understanding of its regulation. Here we report the crystal structure of the catalytic domain of zebrafish PIP5K1A at 3.3 Å resolution. This molecule forms a side-to-side dimer. Mutagenesis study of PIP5K1A reveals two adjacent interfaces for the dimerization and interaction with the DIX domain of the Wnt signalling molecule dishevelled. Although these interfaces are located distally to the catalytic/substrate-binding site, binding to these interfaces either through dimerization or the interaction with DIX stimulates PIP5K1 catalytic activity. DIX binding additionally enhances PIP5K1 substrate binding. Thus, this study elucidates regulatory mechanisms for this lipid kinase and provides a paradigm for the understanding of PIP5K1 regulation by their interacting molecules. PMID:26365782

  10. Ror2/Frizzled Complex Mediates Wnt5a-Induced AP-1 Activation by Regulating Dishevelled Polymerization▿ †

    PubMed Central

    Nishita, Michiru; Itsukushima, Sumiyo; Nomachi, Akira; Endo, Mitsuharu; Wang, ZhiChao; Inaba, Daisuke; Qiao, Sen; Takada, Shinji; Kikuchi, Akira; Minami, Yasuhiro

    2010-01-01

    The receptor tyrosine kinase Ror2 acts as a receptor or coreceptor for Wnt5a to mediate Wnt5a-induced activation of the Wnt/JNK pathway and inhibition of the β-catenin-dependent canonical Wnt pathway. However, little is known about how Ror2 cooperates with another receptor component(s) to mediate Wnt5a signaling. We show here that Ror2 regulates Wnt5a-induced polymerization of Dishevelled (Dvl) and that this Ror2-mediated regulation of Dvl is independent of the cytoplasmic region of Ror2. Ror2 can associate with Frizzled7 (Fz7) via its extracellular cysteine-rich domain to form a receptor complex that is required for the regulation of Dvl and activation of the AP-1 promoter after Wnt5a stimulation. Suppressed expression of Fz7 indeed results in the inhibition of Wnt5a-induced polymerization of Dvl and AP-1 activation. Interestingly, both the DIX and the DEP domains of Dvl are indispensable for Dvl polymerization and subsequent AP-1 activation after Wnt5a stimulation. We further show that polymerized Dvl is colocalized with Rac1 and that suppressed expression of Rac1 inhibits Wnt5a-induced AP-1 activation. Collectively, our results indicate that Ror2/Fz receptor complex plays an important role in the Wnt5a/Rac1/AP-1 pathway by regulating the polymerization of Dvl. PMID:20457807

  11. The PCP effector Fuzzy controls cilial assembly and signaling by recruiting Rab8 and Dishevelled to the primary cilium

    PubMed Central

    Zilber, Yulia; Babayeva, Sima; Seo, Jung Hwa; Liu, Jia Jia; Mootin, Steven; Torban, Elena

    2013-01-01

    The planar cell polarity (PCP) pathway controls multiple cellular processes during vertebrate development. Recently the PCP pathway was implicated in ciliogenesis and in ciliary function. The primary cilium is an apically projecting solitary organelle that is generated via polarized intracellular trafficking. Because it acts as a signaling nexus, defects in ciliogenesis or cilial function cause multiple congenital anomalies in vertebrates. Loss of the PCP effector Fuzzy affects PCP signaling and formation of primary cilia; however, the mechanisms underlying these processes are largely unknown. Here we report that Fuzzy localizes to the basal body and ciliary axoneme and is essential for ciliogenesis by delivering Rab8 to the basal body and primary cilium. Fuzzy appears to control subcellular localization of the core PCP protein Dishevelled, recruiting it to Rab8-positive vesicles and to the basal body and cilium. We show that loss of Fuzzy results in inhibition of PCP signaling and hyperactivation of the canonical WNT pathway. We propose a mechanism by which Fuzzy participates in ciliogenesis and affects both canonical WNT and PCP signaling. PMID:23303251

  12. The core planar cell polarity gene prickle interacts with flamingo to promote sensory axon advance in the Drosophila embryo.

    PubMed

    Mrkusich, Eli M; Flanagan, Dustin J; Whitington, Paul M

    2011-10-01

    The atypical cadherin Drosophila protein Flamingo and its vertebrate homologues play widespread roles in the regulation of both dendrite and axon growth. However, little is understood about the molecular mechanisms that underpin these functions. Whereas flamingo interacts with a well-defined group of genes in regulating planar cell polarity, previous studies have uncovered little evidence that the other core planar cell polarity genes are involved in regulation of neurite growth. We present data in this study showing that the planar cell polarity gene prickle interacts with flamingo in regulating sensory axon advance at a key choice point - the transition between the peripheral nervous system and the central nervous system. The cytoplasmic tail of the Flamingo protein is not required for this interaction. Overexpression of another core planar cell polarity gene dishevelled produces a similar phenotype to prickle mutants, suggesting that this gene may also play a role in regulation of sensory axon advance.

  13. Disheveled mediated planar cell polarity signaling is required in the second heart field lineage for outflow tract morphogenesis.

    PubMed

    Sinha, Tanvi; Wang, Bing; Evans, Sylvia; Wynshaw-Boris, Anthony; Wang, Jianbo

    2012-10-01

    Disheveled (Dvl) is a key regulator of both the canonical Wnt and the planar cell polarity (PCP) pathway. Previous genetic studies in mice indicated that outflow tract (OFT) formation requires Dvl1 and 2, but it was unclear which pathway was involved and whether Dvl1/2-mediated signaling was required in the second heart field (SHF) or the cardiac neural crest (CNC) lineage, both of which are critical for OFT development. In this study, we used Dvl1/2 null mice and a set of Dvl2 BAC transgenes that function in a pathway-specific fashion to demonstrate that Dvl1/2-mediated PCP signaling is essential for OFT formation. Lineage-specific gene-ablation further indicated that Dvl1/2 function is dispensable in the CNC, but required in the SHF for OFT lengthening to promote cardiac looping. Mutating the core PCP gene Vangl2 and non-canonical Wnt gene Wnt5a recapitulated the OFT morphogenesis defects observed in Dvl1/2 mutants. Consistent with genetic interaction studies suggesting that Wnt5a signals through the PCP pathway, Dvl1/2 and Wnt5a mutants display aberrant cell packing and defective actin polymerization and filopodia formation specifically in SHF cells in the caudal splanchnic mesoderm (SpM), where Wnt5a and Dvl2 are co-expressed specifically. Our results reveal a critical role of PCP signaling in the SHF during early OFT lengthening and cardiac looping and suggest that a Wnt5a→ Dvl PCP signaling cascade may regulate actin polymerization and protrusive cell behavior in the caudal SpM to promote SHF deployment, OFT lengthening and cardiac looping.

  14. Disheveled Mediated Planar Cell Polarity Signaling is Required in the Second Heart Field Lineage for Outflow Tract Morphogenesis

    PubMed Central

    Sinha, Tanvi; Wang, Bing; Evans, Sylvia; Wynshaw-Boris, Anthony; Wang, Jianbo

    2012-01-01

    Disheveled (Dvl) is a key regulator of both the canonical Wnt and the planar cell polarity (PCP) pathway. Previous genetic studies in mice indicated that outflow tract (OFT) formation requires Dvl1 and 2, but it was unclear which pathway was involved and whether Dvl1/2-mediated signaling was required in the second heart field (SHF) or the cardiac neural crest (CNC) lineage, both of which are critical for OFT development. In this study, we used Dvl1/2 null mice and a set of Dvl2 BAC transgenes that function in a pathway-specific fashion to demonstrate that Dvl1/2-mediated PCP signaling is essential for OFT formation. Lineage-specific gene ablation further indicated that Dvl1/2 function is dispensable in the CNC, but required in the SHF for OFT lengthening to promote cardiac looping. Mutating the core PCP gene Vangl2 and non-canonical Wnt gene Wnt5a recapitulated the OFT morphogenesis defects observed in Dvl1/2 mutants. Consistent with genetic interaction studies suggesting that Wnt5a signals through the PCP pathway, Dvl1/2 and Wnt5a mutants display aberrant cell packing and defective actin polymerization and filopodia formation specifically in SHF cells in the caudal splanchnic mesoderm (SpM), where Wnt5a and Dvl2 are co-expressed specifically. Our results reveal a critical role of PCP signaling in the SHF during early OFT lengthening and cardiac looping and suggest that a Wnt5a→ Dvl PCP signaling cascade may regulate actin polymerization and protrusive cell behavior in the caudal SpM to promote SHF deployment, OFT lengthening and cardiac looping. PMID:22841628

  15. Toward new Drosophila paradigms.

    PubMed

    Andrioli, Luiz Paulo

    2012-08-01

    The fruit fly Drosophila melanogaster is a great model system in developmental biology studies and related disciplines. In a historical perspective, I focus on the formation of the Drosophila segmental body plan using a comparative approach. I highlight the evolutionary trend of increasing complexity of the molecular segmentation network in arthropods that resulted in an incredible degree of complexity at the gap gene level in derived Diptera. There is growing evidence that Drosophila is a highly derived insect, and we are still far from fully understanding the underlying evolutionary mechanisms that led to its complexity. In addition, recent data have altered how we view the transcriptional regulatory mechanisms that control segmentation in Drosophila. However, these observations are not all bad news for the field. Instead, they stimulate further study of segmentation in Drosophila and in other species as well. To me, these seemingly new Drosophila paradigms are very challenging ones.

  16. Nodal Dependent Differential Localisation of Dishevelled-2 Demarcates Regions of Differing Cell Behaviour in the Visceral Endoderm

    PubMed Central

    Trichas, Georgios; Wilkins, Vivienne; Clements, Melanie; Tada, Masazumi; Rodriguez, Tristan A.; Srinivas, Shankar

    2011-01-01

    The anterior visceral endoderm (AVE), a signalling centre within the simple epithelium of the visceral endoderm (VE), is required for anterior-posterior axis specification in the mouse embryo. AVE cells migrate directionally within the VE, thereby properly positioning the future anterior of the embryo and orientating the primary body axis. AVE cells consistently come to an abrupt stop at the border between the anterior epiblast and extra-embryonic ectoderm, which represents an end-point to their proximal migration. Little is known about the underlying basis for this barrier and how surrounding cells in the VE respond to or influence AVE migration. We use high-resolution 3D reconstructions of protein localisation patterns and time-lapse microscopy to show that AVE cells move by exchanging neighbours within an intact epithelium. Cell movement and mixing is restricted to the VE overlying the epiblast, characterised by the enrichment of Dishevelled-2 (Dvl2) to the lateral plasma membrane, a hallmark of Planar Cell Polarity (PCP) signalling. AVE cells halt upon reaching the adjoining region of VE overlying the extra-embryonic ectoderm, which displays reduced neighbour exchange and in which Dvl2 is excluded specifically from the plasma membrane. Though a single continuous sheet, these two regions of VE show distinct patterns of F-actin localisation, in cortical rings and an apical shroud, respectively. We genetically perturb PCP signalling and show that this disrupts the localisation pattern of Dvl2 and F-actin and the normal migration of AVE cells. In Nodal null embryos, membrane localisation of Dvl2 is reduced, while in mutants for the Nodal inhibitor Lefty1, Dvl2 is ectopically membrane localised, establishing a role for Nodal in modulating PCP signalling. These results show that the limits of AVE migration are determined by regional differences in cell behaviour and protein localisation within an otherwise apparently uniform VE. In addition to coordinating global

  17. Overexpression of the human homologue of Drosophila patched (PTCH) in skin tumours: specificity for basal cell carcinoma.

    PubMed

    Nagano, T; Bito, T; Kallassy, M; Nakazawa, H; Ichihashi, M; Ueda, M

    1999-02-01

    The human homologue of the Drosophila segment polarity gene patched (PTCH) has been identified as the gene for the naevoid basal cell carcinoma (BCC) syndrome and has also been shown to be mutated in sporadic BCC. In order to elucidate the specificity of the PTCH abnormality in BCC, we examined normal skin and 12 BCC and 24 other types of tumour from Japanese patients for expression of the PTCH transcript by competitive reverse transcription-polymerase chain reaction, as mutational inactivation of PTCH leads to overexpression of the mutant transcript owing to failure of a negative feedback mechanism. We found a high level of PTCH expression in all 12 BCCs, while 23 of the other tumours and four specimens of normal skin showed no or weak expression of the gene, with the exception of one specimen from a patient with Bowen's disease which had high expression. These results indicate that the PTCH abnormality plays a critical role in the pathogenesis of BCC.

  18. The PDZ Protein Canoe/AF-6 Links Ras-MAPK, Notch and Wingless/Wnt Signaling Pathways by Directly Interacting with Ras, Notch and Dishevelled

    PubMed Central

    Carmena, Ana; Speicher, Stephan; Baylies, Mary

    2006-01-01

    Over the past few years, it has become increasingly apparent that signal transduction pathways are not merely linear cascades; they are organized into complex signaling networks that require high levels of regulation to generate precise and unique cell responses. However, the underlying regulatory mechanisms by which signaling pathways cross-communicate remain poorly understood. Here we show that the Ras-binding protein Canoe (Cno)/AF-6, a PDZ protein normally associated with cellular junctions, is a key modulator of Wingless (Wg)/Wnt, Ras-Mitogen Activated Protein Kinase (MAPK) and Notch (N) signaling pathways cross-communication. Our data show a repressive effect of Cno/AF-6 on these three signaling pathways through physical interactions with Ras, N and the cytoplasmic protein Dishevelled (Dsh), a key Wg effector. We propose a model in which Cno, through those interactions, actively coordinates, at the membrane level, Ras-MAPK, N and Wg signaling pathways during progenitor specification. PMID:17183697

  19. Drosophila Blastorderm Analysis Software

    SciTech Connect

    2006-10-25

    PointCloudMake analyzes 3D fluorescent images of whole Drosophila embryo and produces a table-style "PointCloud" file which contains the coordinates and volumes of all the nuclei, cells, their associated relative gene expression levels along with morphological features of the embryo. See: Luengo Hendrix et at 2006 3D Morphology and Gene Expression in the Drosophila Blastoderm at Cellular Resolution manuscript submitted LBNL # LBNL-60178 Knowles DW, Keranen SVE, Biggin M. Sudar S (2002) Mapping organism expression levels at cellular resolution in developing Drosophila. In: Conchello JA, Cogswell CJ, Wilson T, editors. Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing IX. pp. 57-64

  20. Meiosis in male Drosophila

    PubMed Central

    McKee, Bruce D.; Yan, Rihui; Tsai, Jui-He

    2012-01-01

    Meiosis entails sorting and separating both homologous and sister chromatids. The mechanisms for connecting sister chromatids and homologs during meiosis are highly conserved and include specialized forms of the cohesin complex and a tightly regulated homolog synapsis/recombination pathway designed to yield regular crossovers between homologous chromatids. Drosophila male meiosis is of special interest because it dispenses with large segments of the standard meiotic script, particularly recombination, synapsis and the associated structures. Instead, Drosophila relies on a unique protein complex composed of at least two novel proteins, SNM and MNM, to provide stable connections between homologs during meiosis I. Sister chromatid cohesion in Drosophila is mediated by cohesins, ring-shaped complexes that entrap sister chromatids. However, unlike other eukaryotes Drosophila does not rely on the highly conserved Rec8 cohesin in meiosis, but instead utilizes two novel cohesion proteins, ORD and SOLO, which interact with the SMC1/3 cohesin components in providing meiotic cohesion. PMID:23087836

  1. In focus: spotted wing drosophila, Drosophila suzukii, across perspectives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An effective response to the invasion of spotted wing Drosophila (SWD), Drosophila suzukii, requires proper taxonomic identification at the initial phase, understanding its basic biology and phenology, developing management tools, transferring information and technology quickly to user groups, and e...

  2. New insights into Drosophila vision.

    PubMed

    Dolph, Patrick

    2008-01-10

    Studies of the Drosophila visual system have provided valuable insights into the function and regulation of phototransduction signaling pathways. Much of this work has stemmed from or relied upon the genetic tools offered by the Drosophila system. In this issue of Neuron, Wang and colleagues and Acharya and colleagues have further exploited the Drosophila genetic system to characterize two new phototransduction players.

  3. Hearing regulates Drosophila aggression.

    PubMed

    Versteven, Marijke; Vanden Broeck, Lies; Geurten, Bart; Zwarts, Liesbeth; Decraecker, Lisse; Beelen, Melissa; Göpfert, Martin C; Heinrich, Ralf; Callaerts, Patrick

    2017-02-21

    Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melanogaster to identify hearing as an important sensory modality in the context of intermale aggressive behavior. We demonstrate that neuronal silencing and targeted knockdown of hearing genes in the fly's auditory organ elicit abnormal aggression. Further, we show that exposure to courtship or aggression song has opposite effects on aggression. Our data define the importance of hearing in the control of Drosophila intermale aggression and open perspectives to decipher how hearing and other sensory modalities are integrated at the neural circuit level.

  4. Chemical sensing in Drosophila.

    PubMed

    Benton, Richard

    2008-08-01

    Chemical sensing begins when peripheral receptor proteins recognise specific environmental stimuli and translate them into spatial and temporal patterns of sensory neuron activity. The chemosensory system of the fruit fly, Drosophila melanogaster, has become a dominant model to understand this process, through its accessibility to a powerful combination of molecular, genetic and electrophysiological analysis. Recent results have revealed many surprises in the biology of peripheral chemosensation in Drosophila, including novel structural and signalling properties of the insect odorant receptors (ORs), combinatorial mechanisms of chemical recognition by the gustatory receptors (GRs), and the implication of Transient Receptor Potential (TRP) ion channels as a novel class of chemosensory receptors.

  5. Studying aging in Drosophila.

    PubMed

    He, Ying; Jasper, Heinrich

    2014-06-15

    Drosophila melanogaster represents one of the most important genetically accessible model organisms for aging research. Studies in flies have identified single gene mutations that influence lifespan and have characterized endocrine signaling interactions that control homeostasis systemically. Recent studies have focused on the effects of aging on specific tissues and physiological processes, providing a comprehensive picture of age-related tissue dysfunction and the loss of systemic homeostasis. Here we review methodological aspects of this work and highlight technical considerations when using Drosophila to study aging and age-related diseases.

  6. Transcription Expression and Clinical Significance of Dishevelled-3 mRNA and δ-Catenin mRNA in Pleural Effusions from Patients with Lung Cancer

    PubMed Central

    Li, Xiao-Yan; Liu, Shu-Li; Cha, Na; Zhao, Yu-Jie; Wang, Shao-Cheng; Li, Wei-Nan; Wang, En-Hua; Wu, Guang-Ping

    2012-01-01

    Objective. To evaluate diagnostic utility of Dishevelled-3 (DVL-3) mRNA and δ-catenin mRNA expression in pleural effusions of patients with lung cancer. Methods. DVL-3 mRNA and δ-catenin mRNA levels were assessed by performing RT-PCR on pleural effusion specimens from patients with lung cancer (n = 75) and with lung benign disease (n = 51). Results. The expressions of DVL-3 mRNA and δ-catenin mRNA were significantly higher in malignant than in benign lung disease (P < 0.01) and were obviously higher than cytology in adenocarcinoma (P < 0.01). In single use, DVL-3 mRNA had the highest specificity (94.1%) and PPV (95.7%), whereas δ-catenin mRNA had the highest sensitivity (92.0%) and NPV (88.5%). When combinations of markers were evaluated together, DVL-3 mRNA and δ-catenin mRNA gave a high-diagnostic performance: sensitivity of 100.0%, NPV of 100.0%, and accuracy of 96.0%, respectively. Conclusion. As molecular markers of detecting pleural micrometastasis, DVL-3 mRNA and δ-catenin mRNA are helpful to diagnose the cancer cells in pleural effusions of patients with lung cancer. PMID:22461838

  7. Direct Binding of the PDZ Domain of Dishevelled to a Conserved Internal Sequence in the C-Terminal Region of Frizzled

    PubMed Central

    Wong, Hing-C.; Bourdelas, Audrey; Krauss, Anke; Lee, Ho-Jin; Shao, Youming; Wu, Dianqing; Mlodzik, Marek; Shi, De-Li; Zheng, Jie

    2015-01-01

    Summary The cytoplasmic protein Dishevelled (Dvl) and the associated membrane-bound receptor Frizzled (Fz) are essential in canonical and noncanonical Wnt signaling pathways. However, the molecular mechanisms underlying this signaling are not well understood. By using NMR spectroscopy, we determined that an internal sequence of Fz binds to the conventional peptide binding site in the PDZ domain of Dvl; this type of site typically binds to C-terminal binding motifs. The C-terminal region of the Dvl inhibitor Dapper (Dpr) and Frodo bound to the same site. In Xenopus, Dvl binding peptides of Fz and Dpr/Frodo inhibited canonical Wnt signaling and blocked Wnt-induced secondary axis formation in a dose-dependent manner, but did not block noncanonical Wnt signaling mediated by the DEP domain. Together, our results identify a missing molecular connection within the Wnt pathway. Differences in the binding affinity of the Dvl PDZ domain and its binding partners may be important in regulating signal transduction by Dvl. PMID:14636582

  8. PAR1b Promotes Cell–Cell Adhesion and Inhibits Dishevelled-mediated Transformation of Madin-Darby Canine Kidney Cells

    PubMed Central

    Elbert, Maya; Cohen, David

    2006-01-01

    Mammalian Par1 is a family of serine/threonine kinases comprised of four homologous isoforms that have been associated with tumor suppression and differentiation of epithelial and neuronal cells, yet little is known about their cellular functions. In polarizing kidney epithelial (Madin-Darby canine kidney [MDCK]) cells, the Par1 isoform Par1b/MARK2/EMK1 promotes the E-cadherin–dependent compaction, columnarization, and cytoskeletal organization characteristic of differentiated columnar epithelia. Here, we identify two functions of Par1b that likely contribute to its role as a tumor suppressor in epithelial cells. 1) The kinase promotes cell–cell adhesion and resistance of E-cadherin to extraction by nonionic detergents, a measure for the association of the E-cadherin cytoplasmic domain with the actin cytoskeleton, which is critical for E-cadherin function. 2) Par1b attenuates the effect of Dishevelled (Dvl) expression, an inducer of wnt signaling that causes transformation of epithelial cells. Although Dvl is a known Par1 substrate in vitro, we determined, after mapping the PAR1b-phosphorylation sites in Dvl, that PAR1b did not antagonize Dvl signaling by phosphorylating the wnt-signaling molecule. Instead, our data suggest that both proteins function antagonistically to regulate the assembly of functional E-cadherin–dependent adhesion complexes. PMID:16707567

  9. Direct binding of the PDZ domain of Dishevelled to a conserved internal sequence in the C-terminal region of Frizzled.

    PubMed

    Wong, Hing-C; Bourdelas, Audrey; Krauss, Anke; Lee, Ho-Jin; Shao, Youming; Wu, Dianqing; Mlodzik, Marek; Shi, De-Li; Zheng, Jie

    2003-11-01

    The cytoplasmic protein Dishevelled (Dvl) and the associated membrane-bound receptor Frizzled (Fz) are essential in canonical and noncanonical Wnt signaling pathways. However, the molecular mechanisms underlying this signaling are not well understood. By using NMR spectroscopy, we determined that an internal sequence of Fz binds to the conventional peptide binding site in the PDZ domain of Dvl; this type of site typically binds to C-terminal binding motifs. The C-terminal region of the Dvl inhibitor Dapper (Dpr) and Frodo bound to the same site. In Xenopus, Dvl binding peptides of Fz and Dpr/Frodo inhibited canonical Wnt signaling and blocked Wnt-induced secondary axis formation in a dose-dependent manner, but did not block noncanonical Wnt signaling mediated by the DEP domain. Together, our results identify a missing molecular connection within the Wnt pathway. Differences in the binding affinity of the Dvl PDZ domain and its binding partners may be important in regulating signal transduction by Dvl.

  10. pangolin encodes a Lef-1 homologue that acts downstream of Armadillo to transduce the Wingless signal in Drosophila.

    PubMed

    Brunner, E; Peter, O; Schweizer, L; Basler, K

    1997-02-27

    Members of the Wnt/Wingless (Wg) family of signalling proteins organize many aspects of animal development by regulating the expression of particular target genes in responding cells. Recent biochemical studies indicate that the vertebrate HMG-domain proteins Lef-1 and XTcf-3 can physically interact with beta-catenin, a homologue of Drosophila Armadillo (Arm), the most downstream component known in the Wnt signal transduction pathway. However, these studies do not address whether the endogenous Lef/Tcf family members are required in vivo to transduce Wnt signals. Using genetic methods in Drosophila, we define a new segment polarity gene, pangolin (pan), and show that its product is required in vivo for Wg signal transduction in embryos and in developing adult tissues. In addition, we show that pan encodes a Lef/Tcf homologue and provide evidence that its protein product binds to the beta-catenin homologue Armadillo in vivo. Finally, we demonstrate that Pan functions downstream of Arm to transduce the Wg signal. Thus, our results indicate that Pan is an essential component of the Wg transduction pathway and suggest that it acts directly to regulate gene transcription in response to Wg signalling.

  11. Heritable Endosymbionts of Drosophila

    PubMed Central

    Mateos, Mariana; Castrezana, Sergio J.; Nankivell, Becky J.; Estes, Anne M.; Markow, Therese A.; Moran, Nancy A.

    2006-01-01

    Although heritable microorganisms are increasingly recognized as widespread in insects, no systematic screens for such symbionts have been conducted in Drosophila species (the primary insect genetic models for studies of evolution, development, and innate immunity). Previous efforts screened relatively few Drosophila lineages, mainly for Wolbachia. We conducted an extensive survey of potentially heritable endosymbionts from any bacterial lineage via PCR screens of mature ovaries in 181 recently collected fly strains representing 35 species from 11 species groups. Due to our fly sampling methods, however, we are likely to have missed fly strains infected with sex ratio-distorting endosymbionts. Only Wolbachia and Spiroplasma, both widespread in insects, were confirmed as symbionts. These findings indicate that in contrast to some other insect groups, other heritable symbionts are uncommon in Drosophila species, possibly reflecting a robust innate immune response that eliminates many bacteria. A more extensive survey targeted these two symbiont types through diagnostic PCR in 1225 strains representing 225 species from 32 species groups. Of these, 19 species were infected by Wolbachia while only 3 species had Spiroplasma. Several new strains of Wolbachia and Spiroplasma were discovered, including ones divergent from any reported to date. The phylogenetic distribution of Wolbachia and Spiroplasma in Drosophila is discussed. PMID:16783009

  12. Aging studies in Drosophila melanogaster.

    PubMed

    Sun, Yaning; Yolitz, Jason; Wang, Cecilia; Spangler, Edward; Zhan, Ming; Zou, Sige

    2013-01-01

    Drosophila is a genetically tractable system ideal for investigating the mechanisms of aging and developing interventions for promoting healthy aging. Here we describe methods commonly used in Drosophila aging research. These include basic approaches for preparation of diets and measurements of lifespan, food intake, and reproductive output. We also describe some commonly used assays to measure changes in physiological and behavioral functions of Drosophila in aging, such as stress resistance and locomotor activity.

  13. Aging Studies in Drosophila melanogaster

    PubMed Central

    Sun, Yaning; Yolitz, Jason; Wang, Cecilia; Spangler, Edward; Zhan, Ming; Zou, Sige

    2015-01-01

    Summary Drosophila is a genetically tractable system ideal for investigating the mechanisms of aging and developing interventions for promoting healthy aging. Here we describe methods commonly used in Drosophila aging research. These include basic approaches for preparation of diets and measurements of lifespan, food intake and reproductive output. We also describe some commonly used assays to measure changes in physiological and behavioral functions of Drosophila in aging, such as stress resistance and locomotor activity. PMID:23929099

  14. Isoform-specific interaction of Flamingo/Starry Night with excess Bazooka affects planar cell polarity in the Drosophila wing.

    PubMed

    Wasserscheid, Isabel; Thomas, Ulrich; Knust, Elisabeth

    2007-04-01

    Epithelia display two types of polarity, apical-basal and planar cell polarity (PCP), and both are crucial for morphogenesis and organogenesis. PCP signaling pathways comprise transmembrane proteins, such as Flamingo/Starry Night, and cytoplasmic, membrane-associated proteins such as Dishevelled. During establishment of PCP in the Drosophila wing, PCP proteins accumulate apically in distinct "cortical domains" on proximal and distal plasma membranes. This finding suggests that their localized function depends on prior definition of apicobasal polarity. Here, we show that overexpression of Bazooka, a PDZ-domain protein essential for apicobasal polarity in the embryo, perturbs development of PCP, but has no effect on apicobasal polarity. The PCP phenotype is associated with a failure to restrict Flamingo/Starry night to the proximal and distal plasma membranes of the wing epithelium. We further demonstrate that flamingo expresses two differentially spliced RNAs in wing imaginal discs, which encode two isoforms of the atypical cadherin Flamingo. The predominant Starry night-type form contains a PDZ-binding motif, which mediates binding to Bazooka in vitro. Pull-down assays support the occurrence of such an interaction in wing imaginal discs. The results suggest that interaction between the apicobasal and planar cell polarity systems has to be tightly coordinated to ensure proper morphogenesis of the wing disc epithelium.

  15. Insulin receptor substrate 1/2 (IRS1/2) regulates Wnt/β-catenin signaling through blocking autophagic degradation of dishevelled2.

    PubMed

    Geng, Yongtao; Ju, Yanfang; Ren, Fangli; Qiu, Ying; Tomita, Yasuhiko; Tomoeda, Miki; Kishida, Mioka; Wang, Yinyin; Jin, Lian; Su, Fuqin; Wei, Chunhong; Jia, Baoqing; Li, Yi; Chang, Zhijie

    2014-04-18

    Wnt signaling plays a pivotal role in cell proliferation, tissue homeostasis, and tumorigenesis. Dishevelled (Dvl) is a central node of Wnt signaling. Insulin receptor substrates (IRSs), as a critical component of insulin signaling, are involved in cell proliferation, metabolism, and cancer development. In this study, we report that IRS1/2 promotes Wnt/β-catenin signaling by stabilizing Dvl2. We found that IRS1/2 interacts with Dvl2. Overexpression of IRS1/2 increased the protein level of Dvl2 and promoted canonical Wnt signaling, as evidenced by the increased T cell-specific factor 4 transcriptional activity and the up-regulation of expression of CYCLIN D1 and c-MYC, two Wnt target genes critical for cell growth, whereas depletion of IRS1/2 reduced the level of Dvl2 and attenuated Wnt/β-catenin signaling. Biochemical analyses revealed that IRS1/2 decreased Lys-63-linked ubiquitination of Dvl2 and stabilized Dvl2 protein via suppressing its autophagy-mediated degradation. We further revealed that IRS1/2 blocks autophagy-induced formation of the Dvl2-p62/SQSTM1 complex, resulting in disabled association of Dvl2 to autophagosomes. We demonstrated that IRS1/2 promoted the induction of epithelial-mesenchymal transition (EMT) and cell proliferation in response to Wnt stimulation, whereas depletion of Dvl2 impaired the IRS1/2-mediated EMT and cell growth. Our findings revealed that IRS1/2 promotes EMT and cell proliferation through stabilizing Dvl2.

  16. Insulin Receptor Substrate 1/2 (IRS1/2) Regulates Wnt/β-Catenin Signaling through Blocking Autophagic Degradation of Dishevelled2*

    PubMed Central

    Geng, Yongtao; Ju, Yanfang; Ren, Fangli; Qiu, Ying; Tomita, Yasuhiko; Tomoeda, Miki; Kishida, Mioka; Wang, Yinyin; Jin, Lian; Su, Fuqin; Wei, Chunhong; Jia, Baoqing; Li, Yi; Chang, Zhijie

    2014-01-01

    Wnt signaling plays a pivotal role in cell proliferation, tissue homeostasis, and tumorigenesis. Dishevelled (Dvl) is a central node of Wnt signaling. Insulin receptor substrates (IRSs), as a critical component of insulin signaling, are involved in cell proliferation, metabolism, and cancer development. In this study, we report that IRS1/2 promotes Wnt/β-catenin signaling by stabilizing Dvl2. We found that IRS1/2 interacts with Dvl2. Overexpression of IRS1/2 increased the protein level of Dvl2 and promoted canonical Wnt signaling, as evidenced by the increased T cell-specific factor 4 transcriptional activity and the up-regulation of expression of CYCLIN D1 and c-MYC, two Wnt target genes critical for cell growth, whereas depletion of IRS1/2 reduced the level of Dvl2 and attenuated Wnt/β-catenin signaling. Biochemical analyses revealed that IRS1/2 decreased Lys-63-linked ubiquitination of Dvl2 and stabilized Dvl2 protein via suppressing its autophagy-mediated degradation. We further revealed that IRS1/2 blocks autophagy-induced formation of the Dvl2-p62/SQSTM1 complex, resulting in disabled association of Dvl2 to autophagosomes. We demonstrated that IRS1/2 promoted the induction of epithelial-mesenchymal transition (EMT) and cell proliferation in response to Wnt stimulation, whereas depletion of Dvl2 impaired the IRS1/2-mediated EMT and cell growth. Our findings revealed that IRS1/2 promotes EMT and cell proliferation through stabilizing Dvl2. PMID:24616100

  17. Differential Regulation of Disheveled in a Novel Vegetal Cortical Domain in Sea Urchin Eggs and Embryos: Implications for the Localized Activation of Canonical Wnt Signaling

    PubMed Central

    Peng, ChiehFu Jeff; Wikramanayake, Athula H.

    2013-01-01

    Pattern formation along the animal-vegetal (AV) axis in sea urchin embryos is initiated when canonical Wnt (cWnt) signaling is activated in vegetal blastomeres. The mechanisms that restrict cWnt signaling to vegetal blastomeres are not well understood, but there is increasing evidence that the egg’s vegetal cortex plays a critical role in this process by mediating localized “activation” of Disheveled (Dsh). To investigate how Dsh activity is regulated along the AV axis, sea urchin-specific Dsh antibodies were used to examine expression, subcellular localization, and post-translational modification of Dsh during development. Dsh is broadly expressed during early sea urchin development, but immunolocalization studies revealed that this protein is enriched in a punctate pattern in a novel vegetal cortical domain (VCD) in the egg. Vegetal blastomeres inherit this VCD during embryogenesis, and at the 60-cell stage Dsh puncta are seen in all cells that display nuclear β-catenin. Analysis of Dsh post-translational modification using two-dimensional Western blot analysis revealed that compared to Dsh pools in the bulk cytoplasm, this protein is differentially modified in the VCD and in the 16-cell stage micromeres that partially inherit this domain. Dsh localization to the VCD is not directly affected by disruption of microfilaments and microtubules, but unexpectedly, microfilament disruption led to degradation of all the Dsh pools in unfertilized eggs over a period of incubation suggesting that microfilament integrity is required for maintaining Dsh stability. These results demonstrate that a pool of differentially modified Dsh in the VCD is selectively inherited by the vegetal blastomeres that activate cWnt signaling in early embryos, and suggests that this domain functions as a scaffold for localized Dsh activation. Localized cWnt activation regulates AV axis patterning in many metazoan embryos. Hence, it is possible that the VCD is an evolutionarily conserved

  18. The Drosophila Auditory System

    PubMed Central

    Boekhoff-Falk, Grace; Eberl, Daniel F.

    2013-01-01

    Development of a functional auditory system in Drosophila requires specification and differentiation of the chordotonal sensilla of Johnston’s organ (JO) in the antenna, correct axonal targeting to the antennal mechanosensory and motor center (AMMC) in the brain, and synaptic connections to neurons in the downstream circuit. Chordotonal development in JO is functionally complicated by structural, molecular and functional diversity that is not yet fully understood, and construction of the auditory neural circuitry is only beginning to unfold. Here we describe our current understanding of developmental and molecular mechanisms that generate the exquisite functions of the Drosophila auditory system, emphasizing recent progress and highlighting important new questions arising from research on this remarkable sensory system. PMID:24719289

  19. Drosophila by the dozen

    SciTech Connect

    Celniker, Susan E.; Hoskins, Roger A.

    2007-07-13

    This year's conference on Drosophila research illustratedwell the current focus of Drosophila genomics on the comprehensiveidentification of functional elements in the genome sequence, includingmRNA transcripts arising from multiple alternative start sites and splicesites, a multiplicity of noncoding transcripts and small RNAs,identification of binding sites for transcription factors, sequenceconservation in related species and sequence variation within species.Resources and technologies for genetics and functional genomics aresteadily being improved, including the building of collections oftransposon insertion mutants and hairpin constructs for RNA interference(RNAi). The conference also highlighted progress in the use of genomicinformation by many laboratories to study diverse aspects of biology andmodels of human disease. Here we will review a few highlights of especialinterest to readers of Genome Biology.

  20. Sexual circuitry in Drosophila.

    PubMed

    Auer, Thomas O; Benton, Richard

    2016-06-01

    The sexual behavior of Drosophila melanogaster is an outstanding paradigm to understand the molecular and neuronal basis of sophisticated animal actions. We discuss recent advances in our knowledge of the genetic hardwiring of the underlying neuronal circuitry, and how pertinent sensory cues are differentially detected and integrated in the male and female brain. We also consider how experience influences these circuits over short timescales, and the evolution of these pathways over longer timescales to endow species-specific sexual displays and responses.

  1. The Drosophila melanogaster host model

    PubMed Central

    Igboin, Christina O.; Griffen, Ann L.; Leys, Eugene J.

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed. PMID:22368770

  2. Myc Function in Drosophila

    PubMed Central

    Gallant, Peter

    2013-01-01

    Drosophila contains a single MYC gene. Like its vertebrate homologs, it encodes a transcription factor that activates many targets, including prominently genes involved in ribosome biogenesis and translation. This activity makes Myc a central regulator of growth and/or proliferation of many cell types, such as imaginal disc cells, polyploid cells, stem cells, and blood cells. Importantly, not only does Myc act cell autonomously but it also affects the fate of adjacent cells and tissues. This potential of Myc is harnessed by many different signaling pathways, involving, among others, Wg, Dpp, Hpo, ecdysone, insulin, and mTOR. PMID:24086064

  3. Feeding regulation in Drosophila

    PubMed Central

    Pool, Allan-Hermann; Scott, Kristin

    2014-01-01

    Neuromodulators play a key role in adjusting animal behavior based on environmental cues and internal needs. Here, we review the regulation of Drosophila feeding behavior to illustrate how neuromodulators achieve behavioral plasticity. Recent studies have made rapid progress in determining molecular and cellular mechanisms that translate the metabolic needs of the fly into changes in neuroendocrine and neuromodulatory states. These neuromodulators in turn promote or inhibit discrete feeding behavioral subprograms. This review highlights the links between physiological needs, neuromodulatory states, and feeding decisions. PMID:24937262

  4. Myoblast fusion in Drosophila

    SciTech Connect

    Haralalka, Shruti; Abmayr, Susan M.

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  5. Deconstructing Memory in Drosophila

    PubMed Central

    Margulies, Carla; Tully, Tim; Dubnau, Josh

    2011-01-01

    Unlike most organ systems, which have evolved to maintain homeostasis, the brain has been selected to sense and adapt to environmental stimuli by constantly altering interactions in a gene network that functions within a larger neural network. This unique feature of the central nervous system provides a remarkable plasticity of behavior, but also makes experimental investigations challenging. Each experimental intervention ramifies through both gene and neural networks, resulting in unpredicted and sometimes confusing phenotypic adaptations. Experimental dissection of mechanisms underlying behavioral plasticity ultimately must accomplish an integration across many levels of biological organization, including genetic pathways acting within individual neurons, neural network interactions which feed back to gene function, and phenotypic observations at the behavioral level. This dissection will be more easily accomplished for model systems such as Drosophila, which, compared with mammals, have relatively simple and manipulable nervous systems and genomes. The evolutionary conservation of behavioral phenotype and the underlying gene function ensures that much of what we learn in such model systems will be relevant to human cognition. In this essay, we have not attempted to review the entire Drosophila memory field. Instead, we have tried to discuss particular findings that provide some level of intellectual synthesis across three levels of biological organization: behavior, neural circuitry and biochemical pathways. We have attempted to use this integrative approach to evaluate distinct mechanistic hypotheses, and to propose critical experiments that will advance this field. PMID:16139203

  6. Epigenetic regulation in Drosophila.

    PubMed

    Lyko, F; Beisel, C; Marhold, J; Paro, R

    2006-01-01

    Epigenetic regulation of gene transcription relies on molecular marks like DNA methylation or histone modifications. Here we review recent advances in our understanding of epigenetic regulation in the fruit fly Drosophila melanogaster. In the past, DNA methylation research has primarily utilized mammalian model systems. However, several recent landmark discoveries have been made in other organisms. For example, the interaction between DNA methylation and histone methylation was first described in the filamentous fungus Neurospora crassa. Another example is provided by the interaction between epigenetic modifications and the RNA interference (RNAi) machinery that was first reported in the fission yeast Schizosaccharomyces pombe. Another organism with great experimental power is the fruit fly Drosophila. Epigenetic regulation by chromatin has been extensively analyzed in the fly and several of the key components have been discovered in this organism. In this chapter, we will focus on three aspects that represent the complexity of epigenetic gene regulation. (1) We will discuss the available data about the DNA methylation system, (2) we will illuminate the interaction between DNA methylation and chromatin regulation, and (3) we will provide an overview over the Polycomb system of epigenetic chromatin modifiers that has proved to be an important paradigm for a chromatin system regulating epigenetic programming.

  7. Cytoplasmic myosin from Drosophila melanogaster

    PubMed Central

    1986-01-01

    Myosin is identified and purified from three different established Drosophila melanogaster cell lines (Schneider's lines 2 and 3 and Kc). Purification entails lysis in a low salt, sucrose buffer that contains ATP, chromatography on DEAE-cellulose, precipitation with actin in the absence of ATP, gel filtration in a discontinuous KI-KCl buffer system, and hydroxylapatite chromatography. Yield of pure cytoplasmic myosin is 5-10%. This protein is identified as myosin by its cross-reactivity with two monoclonal antibodies against human platelet myosin, the molecular weight of its heavy chain, its two light chains, its behavior on gel filtration, its ATP-dependent affinity for actin, its characteristic ATPase activity, its molecular morphology as demonstrated by platinum shadowing, and its ability to form bipolar filaments. The molecular weight of the cytoplasmic myosin's light chains and peptide mapping and immunochemical analysis of its heavy chains demonstrate that this myosin, purified from Drosophila cell lines, is distinct from Drosophila muscle myosin. Two-dimensional thin layer maps of complete proteolytic digests of iodinated muscle and cytoplasmic myosin heavy chains demonstrate that, while the two myosins have some tryptic and alpha-chymotryptic peptides in common, most peptides migrate with unique mobility. One-dimensional peptide maps of SDS PAGE purified myosin heavy chain confirm these structural data. Polyclonal antiserum raised and reacted against Drosophila myosin isolated from cell lines cross-reacts only weakly with Drosophila muscle myosin isolated from the thoraces of adult Drosophila. Polyclonal antiserum raised against Drosophila muscle myosin behaves in a reciprocal fashion. Taken together our data suggest that the myosin purified from Drosophila cell lines is a bona fide cytoplasmic myosin and is very likely the product of a different myosin gene than the muscle myosin heavy chain gene that has been previously identified and characterized. PMID

  8. Review: Thermal preference in Drosophila

    PubMed Central

    Dillon, Michael E.; Wang, George; Garrity, Paul A.; Huey, Raymond B.

    2009-01-01

    Environmental temperature strongly affects physiology of ectotherms. Small ectotherms, like Drosophila, cannot endogenously regulate body temperature so must rely on behavior to maintain body temperature within a physiologically permissive range. Here we review what is known about Drosophila thermal preference. Work on thermal behavior in this group is particularly exciting because it provides the opportunity to connect genes to neuromolecular mechanisms to behavior to fitness in the wild. PMID:20161211

  9. Safeguarding genetic information in Drosophila.

    PubMed

    Su, Tin Tin

    2011-12-01

    Eukaryotic cells employ a plethora of conserved proteins and mechanisms to ensure genome integrity. In metazoa, these mechanisms must operate in the context of organism development. This mini-review highlights two emerging features of DNA damage responses in Drosophila: a crosstalk between DNA damage responses and components of the spindle assembly checkpoint, and increasing evidence for the effect of DNA damage on the developmental program at multiple points during the Drosophila life cycle.

  10. Cytokines in Drosophila immunity.

    PubMed

    Vanha-Aho, Leena-Maija; Valanne, Susanna; Rämet, Mika

    2016-02-01

    Cytokines are a large and diverse group of small proteins that can affect many biological processes, but most commonly cytokines are known as mediators of the immune response. In the event of an infection, cytokines are produced in response to an immune stimulus, and they function as key regulators of the immune response. Cytokines come in many shapes and sizes, and although they vary greatly in structure, their functions have been well conserved in evolution. The immune signaling pathways that respond to cytokines are remarkably conserved from fly to man. Therefore, Drosophila melanogaster, provides an excellent platform for studying the biology and function of cytokines. In this review, we will describe the cytokines and cytokine-like molecules found in the fly and discuss their roles in host immunity.

  11. Optogenetics in Drosophila Neuroscience.

    PubMed

    Riemensperger, Thomas; Kittel, Robert J; Fiala, André

    2016-01-01

    Optogenetic techniques enable one to target specific neurons with light-sensitive proteins, e.g., ion channels, ion pumps, or enzymes, and to manipulate their physiological state through illumination. Such artificial interference with selected elements of complex neuronal circuits can help to determine causal relationships between neuronal activity and the effect on the functioning of neuronal circuits controlling animal behavior. The advantages of optogenetics can best be exploited in genetically tractable animals whose nervous systems are, on the one hand, small enough in terms of cell numbers and to a certain degree stereotypically organized, such that distinct and identifiable neurons can be targeted reproducibly. On the other hand, the neuronal circuitry and the behavioral repertoire should be complex enough to enable one to address interesting questions. The fruit fly Drosophila melanogaster is a favorable model organism in this regard. However, the application of optogenetic tools to depolarize or hyperpolarize neurons through light-induced ionic currents has been difficult in adult flies. Only recently, several variants of Channelrhodopsin-2 (ChR2) have been introduced that provide sufficient light sensitivity, expression, and stability to depolarize central brain neurons efficiently in adult Drosophila. Here, we focus on the version currently providing highest photostimulation efficiency, ChR2-XXL. We exemplify the use of this optogenetic tool by applying it to a widely used aversive olfactory learning paradigm. Optogenetic activation of a population of dopamine-releasing neurons mimics the reinforcing properties of a punitive electric shock typically used as an unconditioned stimulus. In temporal coincidence with an odor stimulus this artificially induced neuronal activity causes learning of the odor signal, thereby creating a light-induced memory.

  12. Ubiquitin Ligase HUWE1 Regulates Axon Branching through the Wnt/β-Catenin Pathway in a Drosophila Model for Intellectual Disability

    PubMed Central

    Vandewalle, Joke; Langen, Marion; Zschaetzsch, Marlen; Nijhof, Bonnie; Kramer, Jamie M.; Brems, Hilde; Bauters, Marijke; Lauwers, Elsa; Srahna, Mohammed; Marynen, Peter; Verstreken, Patrik; Schenck, Annette; Hassan, Bassem A.; Froyen, Guy

    2013-01-01

    We recently reported that duplication of the E3 ubiquitin ligase HUWE1 results in intellectual disability (ID) in male patients. However, the underlying molecular mechanism remains unknown. We used Drosophila melanogaster as a model to investigate the effect of increased HUWE1 levels on the developing nervous system. Similar to the observed levels in patients we overexpressed the HUWE1 mRNA about 2-fold in the fly. The development of the mushroom body and neuromuscular junctions were not altered, and basal neurotransmission was unaffected. These data are in agreement with normal learning and memory in the courtship conditioning paradigm. However, a disturbed branching phenotype at the axon terminals of the dorsal cluster neurons (DCN) was detected. Interestingly, overexpression of HUWE1 was found to decrease the protein levels of dishevelled (dsh) by 50%. As dsh as well as Fz2 mutant flies showed the same disturbed DCN branching phenotype, and the constitutive active homolog of β-catenin, armadillo, could partially rescue this phenotype, our data strongly suggest that increased dosage of HUWE1 compromises the Wnt/β-catenin pathway possibly by enhancing the degradation of dsh. PMID:24303071

  13. Genome of Drosophila suzukii, the Spotted Wing Drosophila

    PubMed Central

    Chiu, Joanna C.; Jiang, Xuanting; Zhao, Li; Hamm, Christopher A.; Cridland, Julie M.; Saelao, Perot; Hamby, Kelly A.; Lee, Ernest K.; Kwok, Rosanna S.; Zhang, Guojie; Zalom, Frank G.; Walton, Vaughn M.; Begun, David J.

    2013-01-01

    Drosophila suzukii Matsumura (spotted wing drosophila) has recently become a serious pest of a wide variety of fruit crops in the United States as well as in Europe, leading to substantial yearly crop losses. To enable basic and applied research of this important pest, we sequenced the D. suzukii genome to obtain a high-quality reference sequence. Here, we discuss the basic properties of the genome and transcriptome and describe patterns of genome evolution in D. suzukii and its close relatives. Our analyses and genome annotations are presented in a web portal, SpottedWingFlyBase, to facilitate public access. PMID:24142924

  14. Why Drosophila to Study Phototransduction?

    PubMed Central

    Pak, William L.

    2010-01-01

    This review recounts the early history of Drosophila phototransduction genetics, covering the period between approximately 1966 to 1979. Early in this period, the author felt that there was an urgent need for a new approach in phototransduction research. Through inputs from a number of colleagues, he was led to consider isolating Drosophila mutants that are defective in the electroretinogram. Thanks to the efforts of dedicated associates and technical staff, by the end of this period, he was able to accumulate a large number of such mutants. Particularly important in this effort was the use of the mutant assay protocol based on the “prolonged depolarizing afterpotential.” This collection of mutants formed the basis of the subsequent intensive investigations of the Drosophila phototransduction cascade by many investigators. PMID:20536286

  15. Modelling the Drosophila embryo.

    PubMed

    Jaeger, Johannes

    2009-12-01

    I provide a historical overview on the use of mathematical models to gain insight into pattern formation during early development of the fruit fly Drosophila melanogaster. It is my intention to illustrate how the aims and methodology of modelling have changed from the early beginnings of a theoretical developmental biology in the 1960s to modern-day systems biology. I show that even early modelling attempts addressed interesting and relevant questions, which were not tractable by experimental approaches. Unfortunately, their validation was severely hampered by a lack of specificity and appropriate experimental evidence. There is a simple lesson to be learned from this: we cannot deduce general rules for pattern formation from first principles or spurious reproduction of developmental phenomena. Instead, we must infer such rules (if any) from detailed and accurate studies of specific developmental systems. To achieve this, mathematical modelling must be closely integrated with experimental approaches. I report on progress that has been made in this direction in the past few years and illustrate the kind of novel insights that can be gained from such combined approaches. These insights demonstrate the great potential (and some pitfalls) of an integrative, systems-level investigation of pattern formation.

  16. Micromechanics of Drosophila Audition

    NASA Astrophysics Data System (ADS)

    Göpfert, M. C.; Robert, D.

    2003-02-01

    An analysis is presented of the auditory micromechanics of the fruit fly Drosophila melanogaster. In this animal, the distal part of the antenna constitutes a resonantly tuned sound receiver, the vibrations of which are transduced by a chordotonal sense organ in the antenna's base. Analyzing the mechanical behavior of the antennal receiver by means of microscanning laser Doppler vibrometry, we show that the auditory system of wild-type flies exhibits a hardening stiffness nonlinearity and spontaneously generates oscillations in the absence of external stimuli. According to the deprivation of these mechanical properties in mechanosensory mutants, the receiver's nonlinearity and oscillation activity are introduced by chordotonal auditory neurons. Requiring the mechanoreceptor-specific extracellular linker protein No-mechanoreceptor-potential-A (NompA), NompC mechanosensory transduction channels, Beethoven (Btv), and Touch-insensitive-larva-B (TilB), nonlinearity and oscillation activity of the fly's antennal receiver depend on prominent components of the auditory transduction machinery and seem to originate from motility of auditory receptor cilia.

  17. Iron Absorption in Drosophila melanogaster

    PubMed Central

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-01-01

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

  18. Iron absorption in Drosophila melanogaster.

    PubMed

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-05-17

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration.

  19. Developing a Drosophila Model of Schwannomatosis

    DTIC Science & Technology

    2013-02-01

    scrib–/– animals (Pastor- Pareja et al., 2008). The Drosophila genome encodes a single member of the tumor necrosis factor (TNF) family, named Eiger...activation in Drosophila. Curr. Biol. 16, 1139-1146. Igaki, T., Pastor- Pareja , J. C., Aonuma, H., Miura, M. and Xu, T. (2009). Intrinsic tumor suppression...of high-resolution deletion coverage of the Drosophila melanogaster genome. Nat. Genet. 36, 288-292. Pastor- Pareja , J. C., Wu, M. and Xu. T. (2008

  20. A Drosophila complementary DNA resource

    SciTech Connect

    Rubin, Gerald M.; Hong, Ling; Brokstein, Peter; Evans-Holm, Martha; Frise, Erwin; Stapleton, Mark; Harvey, Damon A.

    2000-03-24

    Collections of nonredundant, full-length complementary DNA (cDNA) clones for each of the model organisms and humans will be important resources for studies of gene structure and function. We describe a general strategy for producing such collections and its implementation, which so far has generated a set of cDNAs corresponding to over 40% of the genes in the fruit fly Drosophila melanogaster.

  1. Drosophila's view on insect vision.

    PubMed

    Borst, Alexander

    2009-01-13

    Within the last 400 million years, insects have radiated into at least a million species, accounting for more than half of all known living organisms: they are the most successful group in the animal kingdom, found in almost all environments of the planet, ranging in body size from a mere 0.1 mm up to half a meter. Their eyes, together with the respective parts of the nervous system dedicated to the processing of visual information, have long been the subject of intense investigation but, with the exception of some very basic reflexes, it is still not possible to link an insect's visual input to its behavioral output. Fortunately for the field, the fruit fly Drosophila is an insect, too. This genetic workhorse holds great promise for the insect vision field, offering the possibility of recording, suppressing or stimulating any single neuron in its nervous system. Here, I shall give a brief synopsis of what we currently know about insect vision, describe the genetic toolset available in Drosophila and give some recent examples of how the application of these tools have furthered our understanding of color and motion vision in Drosophila.

  2. Insulin receptor in Drosophila melanogaster

    SciTech Connect

    Petruzzelli, L.; Herrera, R.; Rosen, O.

    1986-05-01

    A specific, high affinity insulin receptor is present in both adult Drosophila and in Drosophila embryos. Wheat germ lectin-enriched extracts of detergent-solubilized membranes from embryos and adults bind insulin with a K/sub d/ of 15 nM. Binding is specific for insulin; micromolar concentrations of proinsulin, IGFI, and IGFII are required to displace bound /sup 125/I-insulin. Insulin-dependent protein tyrosine kinase activity appears during embryogenesis. It is evident between 6 and 12 hours of development, peaks between 12 and 18 hours and falls in the adult. During 0-6 hours of embryogenesis, and in the adult, a specific protein band (Mr = 135,000) is crosslinked to /sup 125/I-insulin. During 6-12 and 12-18 hours of embryogenesis stages in which insulin-dependent protein tyrosine kinase is high, an additional band (Mr = 100,000) becomes crosslinked to /sup 125/I-insulin. Isolation and DNA sequence analysis of genomic clones encoding the Drosophila insulin receptor will be presented as will the characterization of insulin receptor mRNA's during development.

  3. 'Peer pressure' in larval Drosophila?

    PubMed

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

    2014-06-06

    Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila.

  4. Leigh Syndrome in Drosophila melanogaster

    PubMed Central

    Da-Rè, Caterina; von Stockum, Sophia; Biscontin, Alberto; Millino, Caterina; Cisotto, Paola; Zordan, Mauro A.; Zeviani, Massimo; Bernardi, Paolo; De Pittà, Cristiano; Costa, Rodolfo

    2014-01-01

    Leigh Syndrome (LS) is the most common early-onset, progressive mitochondrial encephalopathy usually leading to early death. The single most prevalent cause of LS is occurrence of mutations in the SURF1 gene, and LSSurf1 patients show a ubiquitous and specific decrease in the activity of mitochondrial respiratory chain complex IV (cytochrome c oxidase, COX). SURF1 encodes an inner membrane mitochondrial protein involved in COX assembly. We established a Drosophila melanogaster model of LS based on the post-transcriptional silencing of CG9943, the Drosophila homolog of SURF1. Knockdown of Surf1 was induced ubiquitously in larvae and adults, which led to lethality; in the mesodermal derivatives, which led to pupal lethality; or in the central nervous system, which allowed survival. A biochemical characterization was carried out in knockdown individuals, which revealed that larvae unexpectedly displayed defects in all complexes of the mitochondrial respiratory chain and in the F-ATP synthase, while adults had a COX-selective impairment. Silencing of Surf1 expression in Drosophila S2R+ cells led to selective loss of COX activity associated with decreased oxygen consumption and respiratory reserve. We conclude that Surf1 is essential for COX activity and mitochondrial function in D. melanogaster, thus providing a new tool that may help clarify the pathogenic mechanisms of LS. PMID:25164807

  5. Optogenetic pacing in Drosophila melanogaster

    PubMed Central

    Alex, Aneesh; Li, Airong; Tanzi, Rudolph E.; Zhou, Chao

    2015-01-01

    Electrical stimulation is currently the gold standard for cardiac pacing. However, it is invasive and nonspecific for cardiac tissues. We recently developed a noninvasive cardiac pacing technique using optogenetic tools, which are widely used in neuroscience. Optogenetic pacing of the heart provides high spatial and temporal precisions, is specific for cardiac tissues, avoids artifacts associated with electrical stimulation, and therefore promises to be a powerful tool in basic cardiac research. We demonstrated optogenetic control of heart rhythm in a well-established model organism, Drosophila melanogaster. We developed transgenic flies expressing a light-gated cation channel, channelrhodopsin-2 (ChR2), specifically in their hearts and demonstrated successful optogenetic pacing of ChR2-expressing Drosophila at different developmental stages, including the larva, pupa, and adult stages. A high-speed and ultrahigh-resolution optical coherence microscopy imaging system that is capable of providing images at a rate of 130 frames/s with axial and transverse resolutions of 1.5 and 3.9 μm, respectively, was used to noninvasively monitor Drosophila cardiac function and its response to pacing stimulation. The development of a noninvasive integrated optical pacing and imaging system provides a novel platform for performing research studies in developmental cardiology. PMID:26601299

  6. Drosophila and Beer: An Experimental Laboratory Exercise

    ERIC Educational Resources Information Center

    Kurvink, Karen

    2004-01-01

    Drosophila melanogaster is a popular organism for studying genetics and development. Maintaining Drosophila on medium prepared with varying concentrations of beer and evaluating the effects on reproduction, life cycle stages and other factors is one of the exercises that is versatile and applicable to many student levels.

  7. Using Drosophila for Studies of Intermediate Filaments.

    PubMed

    Bohnekamp, Jens; Cryderman, Diane E; Thiemann, Dylan A; Magin, Thomas M; Wallrath, Lori L

    2016-01-01

    Drosophila melanogaster is a useful organism for determining protein function and modeling human disease. Drosophila offers a rapid generation time and an abundance of genomic resources and genetic tools. Conservation in protein structure, signaling pathways, and developmental processes make studies performed in Drosophila relevant to other species, including humans. Drosophila models have been generated for neurodegenerative diseases, muscular dystrophy, cancer, and many other disorders. Recently, intermediate filament protein diseases have been modeled in Drosophila. These models have revealed novel mechanisms of pathology, illuminated potential new routes of therapy, and make whole organism compound screens feasible. The goal of this chapter is to outline steps to study intermediate filament function and model intermediate filament-associated diseases in Drosophila. The steps are general and can be applied to study the function of almost any protein. The protocols outlined here are for both the novice and experienced Drosophila researcher, allowing the rich developmental and cell biology that Drosophila offers to be applied to studies of intermediate filaments.

  8. Cryobiological preservation of Drosophila embryos

    SciTech Connect

    Mazur, P.; Schreuders, P.D.; Cole, K.W.; Hall, J.W. ); Mahowald, A.P. )

    1992-12-18

    The inability to cryobiologically preserve the fruit fly Drosophila melanogaster has required that fly stocks be maintained by frequent transfer of adults. This method is costly in terms of time and can lead to loss of stocks. Traditional slow freezing methods do not succeed because the embryos are highly sensitive to chilling. With the procedures described here, 68 percent of precisely staged 15-hour Oregon R (wild-type) embryos hatch after vitrification at -205[degree]C, and 40 percent of the resulting larvae develop into normal adult flies. These embryos are among the most complex organisms successfully preserved by cryobiology.

  9. Chromosome Conformation Capture in Drosophila.

    PubMed

    Li, Hua-Bing

    2016-01-01

    Linear chromatin fiber is packed inside the nuclei as a complex three-dimensional structure, and the organization of the chromatin has important roles in the appropriate spatial and temporal regulation of gene expression. To understand how chromatin organizes inside nuclei, and how regulatory proteins physically interact with genes, chromosome conformation capture (3C) technique provides a powerful and sensitive tool to detect both short- and long-range DNA-DNA interaction. Here I describe the 3C technique to detect the DNA-DNA interactions mediated by insulator proteins that are closely related to PcG in Drosophila, which is also broadly applicable to other systems.

  10. Geotaxis baseline data for Drosophila

    NASA Technical Reports Server (NTRS)

    Schnebel, E. M.; Bhargava, R.; Grossfield, J.

    1987-01-01

    Geotaxis profiles for 20 Drosophila species and semispecies at different ages have been examined using a calibrated, adjustable slant board device. Measurements were taken at 5 deg intervals ranging from 0 deg to 85 deg. Clear strain and species differences are observed, with some groups tending to move upward (- geotaxis) with increasing angles, while others move downward (+ geotaxis). Geotactic responses change with age in some, but not all experimental groups. Sample geotaxis profiles are presented and their application to ecological and aging studies are discussed. Data provide a baseline for future evaluations of the biological effects of microgravity.

  11. Haploidy and androgenesis in Drosophila.

    PubMed Central

    Komma, D J; Endow, S A

    1995-01-01

    Adrogenesis, development from paternal but not maternal chromosomes, can be induced to occur in some organisms, including vertebrates, but has only been reported to occur naturally in interspecific hybrids of the Sicilian stick insect. Androgenesis has not been described previously in Drosophila. We now report the recovery of androgenetic offspring from Drosophila melanogaster females mutant for a gene that affects an oocyte- and embryo-specific alpha-tubulin. The androgenetic exceptions are X,X diploid females that develop from haploid embryos and express paternal markers on all 4 chromosomes. The exceptional females arise by fusion of haploid cleavage nuclei or failure of newly replicated haploid chromosomes to segregate, rather than fusion of two inseminating sperm. The frequency of androgenetic offspring is greatly enhanced by a partial loss-of-function mutant of the NCD (nonclaret disjunctional) microtubule motor protein, suggesting that wild-type NCD functions is pronuclear fusion. Diploidization of haploid paternal chromosome complements results in complete genetic homozygosity, which could facilitate studies of gene variation and mutational load in populations. Images Fig. 2 Fig. 3 PMID:8524868

  12. Automated Tracking of Drosophila Specimens

    PubMed Central

    Chao, Rubén; Macía-Vázquez, Germán; Zalama, Eduardo; Gómez-García-Bermejo, Jaime; Perán, José-Ramón

    2015-01-01

    The fruit fly Drosophila Melanogaster has become a model organism in the study of neurobiology and behavior patterns. The analysis of the way the fly moves and its behavior is of great scientific interest for research on aspects such as drug tolerance, aggression or ageing in humans. In this article, a procedure for detecting, identifying and tracking numerous specimens of Drosophila by means of computer vision-based sensing systems is presented. This procedure allows dynamic information about each specimen to be collected at each moment, and then for its behavior to be quantitatively characterized. The proposed algorithm operates in three main steps: a pre-processing step, a detection and segmentation step, and tracking shape. The pre-processing and segmentation steps allow some limits of the image acquisition system and some visual artifacts (such as shadows and reflections) to be dealt with. The improvements introduced in the tracking step allow the problems corresponding to identity loss and swaps, caused by the interaction between individual flies, to be solved efficiently. Thus, a robust method that compares favorably to other existing methods is obtained. PMID:26258779

  13. Drosophila Genetics in the Classroom

    PubMed Central

    Sofer, W.; Tompkins, L.

    1994-01-01

    Drosophila has long been useful for demonstrating the principles of classical Mendelian genetics in the classroom. In recent years, the organism has also helped students understand biochemical and behavioral genetics. In this connection, this article describes the development of a set of integrated laboratory exercises and descriptive materials--a laborotory module--in biochemical genetics for use by high-school students. The module focuses on the Adh gene and its product, the alcohol dehydrogenase enzyme. Among other activities, students using the module get to measure alcohol tolerance and to assay alcohol dehydrogenase activity in Adh-negative and -postive flies. To effectively present the module in the classroom, teachers attend a month-long Dissemination Institute in the summer. During this period, they learn about other research activities that can be adapted for classroom use. One such activity that has proved popular with teachers and students utilizes Drosophila to introduce some of the concepts of behavioral genetics to the high-school student. By establishing closer interactions between high-school educators and research scientists, the gulf between the two communities can begin to be bridged. It is anticipated that the result of a closer relationship will be that the excitement and creativity of science will be more effectively conveyed to students. PMID:8138175

  14. Drosophila genetics in the classroom.

    PubMed

    Sofer, W; Tompkins, L

    1994-01-01

    Drosophila has long been useful for demonstrating the principles of classical Mendelian genetics in the classroom. In recent years, the organism has also helped students understand biochemical and behavioral genetics. In this connection, this article describes the development of a set of integrated laboratory exercises and descriptive materials--a laboratory module--in biochemical genetics for use by high-school students. The module focuses on the Adh gene and its product, the alcohol dehydrogenase enzyme. Among other activities, students using the module get to measure alcohol tolerance and to assay alcohol dehydrogenase activity in Adh-negative and -positive flies. To effectively present the module in the classroom, teachers attend a month-long Dissemination Institute in the summer. During this period, they learn about other research activities that can be adapted for classroom use. One such activity that has proved popular with teachers and students utilizes Drosophila to introduce some of the concepts of behavioral genetics to the high-school student. By establishing closer interactions between high-school educators and research scientists, the gulf between the two communities can begin to be bridged. It is anticipated that the result of a closer relationship will be that the excitement and creativity of science will be more effectively conveyed to students.

  15. F-actin staining of Drosophila testes.

    PubMed

    Bonaccorsi, Silvia; Giansanti, Maria G; Cenci, Giovanni; Gatti, Maurizio

    2012-01-01

    Preparations of Drosophila testes fixed with paraformaldehyde can be stained for F-actin according to the protocol described here. This staining procedure is particularly suitable for staining the male fusome and the cytokinetic contractile ring.

  16. Gene Regulation Networks for Modeling Drosophila Development

    NASA Technical Reports Server (NTRS)

    Mjolsness, E.

    1999-01-01

    This chapter will very briefly introduce and review some computational experiments in using trainable gene regulation network models to simulate and understand selected episodes in the development of the fruit fly, Drosophila Melanogaster.

  17. The Drosophila cyst stem cell lineage

    PubMed Central

    Zoller, Richard; Schulz, Cordula

    2012-01-01

    In all animals, germline cells differentiate in intimate contact with somatic cells and interactions between germline and soma are particularly important for germline development and function. In the male gonad of Drosophila melanogaster, the developing germline cells are enclosed by somatic cyst cells. The cyst cells are derived from cyst stem cells (CySCs) of somatic origin and codifferentiate with the germline cells. The fast generation cycle and the genetic tractability of Drosophila has made the Drosophila testis an excellent model for studying both the roles of somatic cells in guiding germline development and the interdependence of two separate stem cell lineages. This review focuses on our current understanding of CySC specification, CySC self-renewing divisions, cyst cell differentiation, and soma-germline interactions. Many of the mechanisms guiding these processes in Drosophila testes are similarly essential for the development and function of tissues in other organisms, most importantly for gametogenesis in mammals. PMID:23087834

  18. Ecdysteroid receptors in Drosophila melanogaster adult females

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecdysteroid receptors were identified and partially characterized from total cell extracts of whole animals and dissected tissues from Drosophila melanogaster adult females. Binding studies indicated the presence of two ecdysteroid binding components having high affinity and specificity consistent w...

  19. Gaining insights into diabetic cardiomyopathy from Drosophila

    PubMed Central

    Diop, Soda Balla; Bodmer, Rolf

    2015-01-01

    The high degree of genetic conservation between Drosophila melanogaster and mammals has helped to translate many important findings into new knowledge, and has led to better understanding of many biological processes in vertebrates. For over a century, the Drosophila model has been used in studies aimed at understanding molecular mechanisms implicated in heredity, development, disease progression, and aging. The current epidemic of obesity and associated diabetic cardiomyopathy and heart failure has led to a shift in Drosophila research towards understanding the basic mechanisms leading to metabolic syndrome and associated cardiac risk factors. Here, we discuss recent findings in Drosophila that highlight the importance of this organism as an excellent model to study the effects of metabolic imbalance on cardiac function. PMID:26482877

  20. Progress in understanding the Drosophila dnc locus.

    PubMed

    Nighorn, A; Qiu, Y; Davis, R L

    1994-05-01

    The genetic dissection of learning and memory in Drosophila is two decades old. Recently, a great deal of progress has been made towards isolating new mutants as well as towards a better understanding of the originally isolated ones. This paper reviews the recent developments in the understanding of the structure and function of the gene identified by the first and best-characterized of these mutants, the Drosophila dunce mutant.

  1. Saccadic body turns in walking Drosophila

    PubMed Central

    Geurten, Bart R. H.; Jähde, Philipp; Corthals, Kristina; Göpfert, Martin C.

    2014-01-01

    Drosophila melanogaster structures its optic flow during flight by interspersing translational movements with abrupt body rotations. Whether these “body saccades” are accompanied by steering movements of the head is a matter of debate. By tracking single flies moving freely in an arena, we now discovered that walking Drosophila also perform saccades. Movement analysis revealed that the flies separate rotational from translational movements by quickly turning their bodies by 15 degrees within a tenth of a second. Although walking flies moved their heads by up to 20 degrees about their bodies, their heads moved with the bodies during saccadic turns. This saccadic strategy contrasts with the head saccades reported for e.g., blowflies and honeybees, presumably reflecting optical constraints: modeling revealed that head saccades as described for these latter insects would hardly affect the retinal input in Drosophila because of the lower acuity of its compound eye. The absence of head saccades in Drosophila was associated with the absence of haltere oscillations, which seem to guide head movements in other flies. In addition to adding new twists to Drosophila walking behavior, our analysis shows that Drosophila does not turn its head relative to its body when turning during walking. PMID:25386124

  2. Ectoparasitic mites and their Drosophila hosts.

    PubMed

    Perez-Leanos, Alejandra; Loustalot-Laclette, Mariana Ramirez; Nazario-Yepiz, Nestor; Markow, Therese Ann

    2017-01-02

    Only two parasite interactions are known for Drosophila to date: Allantonematid nematodes associated with mycophagous Drosophilids and the ectoparasitic mite Macrocheles subbadius with the Sonoran Desert endemic Drosophila nigrospiracula. Unlike the nematode-Drosophila association, breadth of mite parasitism on Drosophila species is unknown. As M. subbadius is a generalist, parasitism of additional Drosophilids is expected. We determined the extent and distribution of mite parasitism in nature Drosophilids collected in Mexico and southern California. Thirteen additional species of Drosophilids were infested. Interestingly, 10 belong to the repleta species group of the subgenus Drosophila, despite the fact that the majority of flies collected were of the subgenus Sophophora. In all cases but 2, the associated mites were M. subbadius. Drosophila hexastigma was found to have not only M. subbadius, but another Mesostigmatid mite, Paragarmania bakeri, as well. One D. hydei was also found to have a mite from genus Lasioseius attached. In both choice and no-choice experiments, mites were more attracted to repleta group species than to Sophophoran. The extent of mite parasitism clearly is much broader than previously reported and suggests a host bias mediated either by mite preference and/or some mechanism of resistance in particular Drosophilid lineages.

  3. Ectoparasitic mites and their Drosophila hosts

    PubMed Central

    Perez-Leanos, Alejandra; Loustalot-Laclette, Mariana Ramirez; Nazario-Yepiz, Nestor; Markow, Therese Ann

    2017-01-01

    ABSTRACT Only two parasite interactions are known for Drosophila to date: Allantonematid nematodes associated with mycophagous Drosophilids and the ectoparasitic mite Macrocheles subbadius with the Sonoran Desert endemic Drosophila nigrospiracula. Unlike the nematode-Drosophila association, breadth of mite parasitism on Drosophila species is unknown. As M. subbadius is a generalist, parasitism of additional Drosophilids is expected. We determined the extent and distribution of mite parasitism in nature Drosophilids collected in Mexico and southern California. Thirteen additional species of Drosophilids were infested. Interestingly, 10 belong to the repleta species group of the subgenus Drosophila, despite the fact that the majority of flies collected were of the subgenus Sophophora. In all cases but 2, the associated mites were M. subbadius. Drosophila hexastigma was found to have not only M. subbadius, but another Mesostigmatid mite, Paragarmania bakeri, as well. One D. hydei was also found to have a mite from genus Lasioseius attached. In both choice and no-choice experiments, mites were more attracted to repleta group species than to Sophophoran. The extent of mite parasitism clearly is much broader than previously reported and suggests a host bias mediated either by mite preference and/or some mechanism of resistance in particular Drosophilid lineages. PMID:27540774

  4. Effect of non-nutritive sugars to decrease the survivorship of spotted wing drosophila, Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we investigated the effects of non-nutritive sugars and sugar alcohols on the survivorship of spotted wing drosophila, Drosophila suzukii, and found erythritol and erythrose as potentially toxic to the fly. In a dose-dependent study, erythritol and erythrose significantly reduced fly ...

  5. Behavioral and antennal responses of spotted wing drosophila, drosophila suzukii, to volatiles from fruit extracts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Native to Southeast Asia, the spotted wing drosophila, Drosophila suzukii, has become a serious pest of soft-skinned fruit crops since its introduction into North America and Europe in 2008. Current monitoring strategies use baits based on fermentation products; however, to date, no fruit-based vola...

  6. Invasion biology of Spotted Wing Drosophila (Drosophila suzukii): a global perspective and future priorities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Asian vinegar fly species Drosophila suzukii (spotted-wing Drosophila or SWD) has emerged as an important invasive insect pest of small and stone fruits in both the Americas and Europe since the late 2000’s. While research efforts have rapidly progressed in Asia, North America, and Europe over ...

  7. The susceptibility of small fruits and cherries to Spotted Wing Drosophila, Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: The Spotted Wing Drosophila (SWD), Drosophila suzukii Matsumura, is native to Asia and has been detected in the North American mainland and Europe in 2008-10. SWD is a serious economic pest because it lays eggs within ripening fruit before harvest which can lead to crop loss. The aim ...

  8. Current Recommendations for Managing Spotted Wing Drosophila (SWD), Drosophila suzukii, in PNW Caneberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spotted wing Drosophila (SWD), Drosophila suzukii, was reported in the Pacific Northwest (Oregon, Washington, British Columbia) in 2009. The fly is able to oviposit directly into intact ripe and ripening fruit, so it is of great economic concern to the small fruit industries in region. Fruit i...

  9. Current Recommendations for Managing Spotted Wing Drosophila (SWD), Drosophila suzukii, in PNW Blueberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spotted wing Drosophila (SWD), Drosophila suzukii, was reported in the Pacific Northwest (Oregon, Washington, British Columbia) in 2009. The fly is able to oviposit directly into intact ripe and ripening fruit, so it is of great economic concern to the small fruit industries in region. Fruit i...

  10. Spotted wing drosophila, Drosophila suzukii (Matsumura)(Diptera: drosophilidae), trapped with combinations of wines and vinegars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field trapping experiments evaluated wine and vinegar baits for spotted wing drosophila flies, Drosophila suzukii (Matsumura), and assessed variance in biat attractiveness with wit type, vinegar type, and bait age. A mixture of apple cider vinegar and a Merlot wine attracted more flies than a mixtur...

  11. Molecular neurobiology of Drosophila taste.

    PubMed

    Freeman, Erica Gene; Dahanukar, Anupama

    2015-10-01

    Drosophila is a powerful model in which to study the molecular and cellular basis of taste coding. Flies sense tastants via populations of taste neurons that are activated by compounds of distinct categories. The past few years have borne witness to studies that define the properties of taste neurons, identifying functionally distinct classes of sweet and bitter taste neurons that express unique subsets of gustatory receptor (Gr) genes, as well as water, salt, and pheromone sensing neurons that express members of the pickpocket (ppk) or ionotropic receptor (Ir) families. There has also been significant progress in terms of understanding how tastant information is processed and conveyed to higher brain centers, and modulated by prior dietary experience or starvation.

  12. A Drosophila mechanosensory transduction channel.

    PubMed

    Walker, R G; Willingham, A T; Zuker, C S

    2000-03-24

    Mechanosensory transduction underlies a wide range of senses, including proprioception, touch, balance, and hearing. The pivotal element of these senses is a mechanically gated ion channel that transduces sound, pressure, or movement into changes in excitability of specialized sensory cells. Despite the prevalence of mechanosensory systems, little is known about the molecular nature of the transduction channels. To identify such a channel, we analyzed Drosophila melanogaster mechanoreceptive mutants for defects in mechanosensory physiology. Loss-of-function mutations in the no mechanoreceptor potential C (nompC) gene virtually abolished mechanosensory signaling. nompC encodes a new ion channel that is essential for mechanosensory transduction. As expected for a transduction channel, D. melanogaster NOMPC and a Caenorhabditis elegans homolog were selectively expressed in mechanosensory organs.

  13. Studying Polyglutamine Diseases in Drosophila

    PubMed Central

    Xu, Zhen; Tito, Antonio; Rui, Yan-Ning; Zhang, Sheng

    2015-01-01

    Polyglutamine (polyQ) diseases are a family of dominantly transmitted neurodegenerative disorders caused by an abnormal expansion of CAG trinucleotide repeats in the protein-coding regions of the respective disease-causing genes. Despite their simple genetic basis, the etiology of these diseases is far from clear. Over the past two decades, Drosophila has proven to be successful in modeling this family of neurodegenerative disorders, including the faithful recapitulation of pathological features such as polyQ length-dependent formation of protein aggregates and progressive neuronal degeneration. Additionally, it has been valuable in probing the pathogenic mechanisms, in identifying and evaluating disease modifiers, and in helping elucidate the normal functions of disease-causing genes. Knowledge learned from this simple invertebrate organism has had a large impact on our understanding of these devastating brain diseases. PMID:26257024

  14. Planar cell polarity in Drosophila

    PubMed Central

    Maung, Saw Myat Thanda W

    2011-01-01

    In all multicellular organisms, epithelial cells are not only polarized along the apical-basal axis, but also within the epithelial plane, giving cells a sense of direction. Planar cell polarity (PCP) signaling regulates establishment of polarity within the plane of an epithelium. The outcomes of PCP signaling are diverse and include the determination of cell fates, the generation of asymmetric but highly aligned structures, such as the stereocilia in the human inner ear or the hairs on a fly wing, or the directional migration of cells during convergence and extension during vertebrate gastrulation. In humans, aberrant PCP signaling can result in severe developmental defects, such as open neural tubes (spina bifida), and can cause cystic kidneys. In this review, we discuss the basic mechanism and more recent findings of PCP signaling focusing on Drosophila melanogaster, the model organism in which most key PCP components were initially identified. PMID:21983142

  15. Molecular neurobiology of Drosophila taste

    PubMed Central

    Freeman, Erica Gene; Dahanukar, Anupama

    2015-01-01

    Drosophila is a powerful model in which to study the molecular and cellular basis of taste coding. Flies sense tastants via populations of taste neurons that are activated by compounds of distinct categories. The past few years have borne witness to studies that define the properties of taste neurons, identifying functionally distinct classes of sweet and bitter taste neurons that express unique subsets of gustatory receptor (Gr) genes, as well as water, salt, and pheromone sensing neurons that express members of the pickpocket (ppk) or ionotropic receptor (Ir) families. There has also been significant progress in terms of understanding how tastant information is processed and conveyed to higher brain centers, and modulated by prior dietary experience or starvation. PMID:26102453

  16. The organization of Drosophila genes.

    PubMed

    Maroni, G

    1994-01-01

    This study was designed to examine the range of size variations in the major functional elements of Drosophila genes and to test whether those size variations occur independently of each other. In a sample of 111 genes the following median values occur: leaders, 123 base pairs (bp); coding regions, 1242 bp; 3' untranslated regions (3'UTR), 246 bp; mRNAs, 1803 bp; 3' terminal exons 843 bp; and exons upstream of the last one 233 bp. Introns show a bimodal distribution with medians of 62 and 595 bp. Unexpected size correlations are evident for several of these elements. The size of the leader, for example, is correlated with the sizes of the coding region and the 3'UTR with very high levels of significance, and the size of the first intron is similarly correlated with the sizes of each of the individual components of the mature mRNA.

  17. Resources for Biological Annotation of the Drosophila Genome

    SciTech Connect

    Gerald M. Rubin

    2005-08-08

    This project supported seed money for the development of cDNA and genetic resources to support studies of the Drosophila melanogaster genome. Key publications supported by this work that provide additional detail: (1) ''The Drosophila gene collection: identification of putative full-length cDNAs for 70% of D. melanogaster genes''; and (2) ''The Berkeley Drosophila Genome Project gene disruption project: Single P-element insertions mutating 25% of vital Drosophila genes''.

  18. Phylogenetic Relationships among DROSOPHILA LONGICORNIS, DROSOPHILA PROPACHUCA and DROSOPHILA PACHUCA, a Triad of Sibling Species

    PubMed Central

    Wasserman, Marvin; Koepfer, H. Roberta

    1977-01-01

    Drosophila longicornis, D. propachuca and D. pachuca comprise a triad of sibling species. They are morphologically indistinguishable, sympatric forms that, under laboratory conditions, are capable of exchanging genes through the production of fertile F1 females. However, we have no evidence for introgressive hybridization in nature. The chromosomal constitution of our strains indicates that the ancestral species had the Primitive E gene sequence, and therefore differed from the standard repleta sequence by being Xabc; 2abcg; 3abc. This Primitive E sequence is found in both D. propachuca and D. longicornis. Each of these two species has its own unique rearrangements. D. pachuca is a derived species, which evolved from propachuca. It is cytologically more advanced and has, as its most primitive gene arrangement, one of the more advanced arrangements found in propachuca. PMID:17248778

  19. Enhancing Undergraduate Teaching and Research with a "Drosophila" Virginizing System

    ERIC Educational Resources Information Center

    Venema, Dennis R.

    2006-01-01

    Laboratory exercises using "Drosophila" crosses are an effective pedagogical method to complement traditional lecture and textbook presentations of genetics. Undergraduate thesis research is another common setting for using "Drosophila." A significant barrier to using "Drosophila" for undergraduate teaching or research is the time and skill…

  20. Drosophila chem mutations disrupt epithelial polarity in Drosophila embryos

    PubMed Central

    Zamudio-Arroyo, José M.

    2016-01-01

    Drosophila embryogenesis has proven to be an extremely powerful system for developmental gene discovery and characterization. We isolated five new EMS-induced alleles that do not complement the l(3R)5G83 lethal line isolated in the Nüsslein-Volhard and Wieschaus screens. We have named this locus chem. Lethality of the new alleles as homozygous zygotic mutants is not completely penetrant, and they have an extended phenocritical period. Like the original allele, a fraction of mutant embryos die with cuticular defects, notably head involution and dorsal closure defects. Embryonic defects are much more extreme in germline clones, where the majority of mutant embryos die during embryogenesis and do not form cuticle, implying a strong chem maternal contribution. chem mutations genetically interact with mutations in cytoskeletal genes (arm) and with mutations in the epithelial polarity genes coracle, crumbs, and yurt. chem mutants dorsal open defects are similar to those present in yurt mutants, and, likewise, they have epithelial polarity defects. chem1 and chem3 mutations suppress yurt3, and chem3 mutants suppress crumbs1 mutations. In contrast, chem1 and coracle2 mutations enhance each other. Compared to controls, in chem mutants in embryonic lateral epithelia Crumbs expression is mislocalized and reduced, Coracle is increased and mislocalized basally at embryonic stages 13–14, then reduced at stage 16. Arm expression has a similar pattern but levels are reduced. PMID:27920954

  1. Environmental ethanol as an ecological constraint on dietary breadth of Spotted-Wing Drosophila, Drosophila suzukii Mat. (Diptera: Drosophilidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted-wing Drosophila (SWD), Drosophila suzukii, is a recent fruit pest of the Americas whose destructiveness stems from its subcutaneous insertion of eggs into cultivated berries via a female’s prominent double bladed and serrated ovipositor. Atypical of most other Drosophila, D. suzukii adults a...

  2. Comparison of human and Drosophila atlastin GTPases.

    PubMed

    Wu, Fuyun; Hu, Xiaoyu; Bian, Xin; Liu, Xinqi; Hu, Junjie

    2015-02-01

    Formation of the endoplasmic reticulum (ER) network requires homotypic membrane fusion, which involves a class of atlastin (ATL) GTPases. Purified Drosophila ATL is capable of mediating vesicle fusion in vitro, but such activity has not been reported for any other ATLs. Here, we determined the preliminary crystal structure of the cytosolic segment of Drosophila ATL in a GDP-bound state. The structure reveals a GTPase domain dimer with the subsequent three-helix bundles associating with their own GTPase domains and pointing in opposite directions. This conformation is similar to that of human ATL1, to which GDP and high concentrations of inorganic phosphate, but not GDP only, were included. Drosophila ATL restored ER morphology defects in mammalian cells lacking ATLs, and measurements of nucleotide-dependent dimerization and GTPase activity were comparable for Drosophila ATL and human ATL1. However, purified and reconstituted human ATL1 exhibited no in vitro fusion activity. When the cytosolic segment of human ATL1 was connected to the transmembrane (TM) region and C-terminal tail (CT) of Drosophila ATL, the chimera still exhibited no fusion activity, though its GTPase activity was normal. These results suggest that GDP-bound ATLs may adopt multiple conformations and the in vitro fusion activity of ATL cannot be achieved by a simple collection of functional domains.

  3. 31 Flavors of Drosophila Rab proteins

    SciTech Connect

    Zhang, Jun; Schulze, Karen L.; Hiesinger, P. Robin; Suyama, Kaye; Wang, Stream; Fish, Matthew; Acar, Melih; Hoskins, Roger A.; Bellen, HugoJ.; Scott, Matthew P.

    2007-04-03

    Rab proteins are small GTPases that play important roles intransport of vesicle cargo and recruitment, association of motor andother proteins with vesicles, and docking and fusion of vesicles atdefined locations. In vertebrates, more than 75 Rab genes have beenidentified, some of which have been intensively studied for their rolesin endosome and synaptic vesicle trafficking. Recent studies of thefunctions of certain Rab proteins have revealed specific roles inmediating developmental signal transduction. We have begun a systematicgenetic study of the 33 Rab genes in Drosophila. Most of the fly proteinsare clearly related to specific vertebrate proteins. We report here thecreation of a set of transgenic fly lines that allow spatially andtemporally regulated expression of Drosophila Rab proteins. We generatedfluorescent protein-tagged wild-type, dominant-negative, andconstitutively active forms of 31 Drosophila Rab proteins. We describeDrosophila Rab expression patterns during embryogenesis, the subcellularlocalization of some Rab proteins, and comparisons of the localization ofwild-type, dominant-negative, and constitutively active forms of selectedRab proteins. The high evolutionary conservation and low redundancy ofDrosophila Rab proteins make these transgenic lines a useful toolkit forinvestigating Rab functions in vivo.

  4. Gut-associated microbes of Drosophila melanogaster

    PubMed Central

    Broderick, Nichole; Lemaitre, Bruno

    2012-01-01

    There is growing interest in using Drosophila melanogaster to elucidate mechanisms that underlie the complex relationships between a host and its microbiota. In addition to the many genetic resources and tools Drosophila provides, its associated microbiota is relatively simple (1–30 taxa), in contrast to the complex diversity associated with vertebrates (> 500 taxa). These attributes highlight the potential of this system to dissect the complex cellular and molecular interactions that occur between a host and its microbiota. In this review, we summarize what is known regarding the composition of gut-associated microbes of Drosophila and their impact on host physiology. We also discuss these interactions in the context of their natural history and ecology and describe some recent insights into mechanisms by which Drosophila and its gut microbiota interact. “Workers with Drosophila have been considered fortunate in that they deal with the first multicellular invertebrate to be cultured monoxenically (Delcourt and Guyenot, 1910); the first to be handled axenically on a semisynthetic diet (Guyenot, 1917); and the first to be grown on a defined diet (Schultz et al., 1946). This list of advantages is somewhat embarrassing, since it implies an interest in nutrition that, in reality, was only secondary. The very first studies were concerned with the reduction of variability in genetic experiments (Delcourt and Guyenot, 1910) and standardization of the nutritional environment.” -James Sang, 1959 Ann NY Acad 1 PMID:22572876

  5. Receptor Tyrosine Kinases in Drosophila Development

    PubMed Central

    Sopko, Richelle; Perrimon, Norbert

    2013-01-01

    Tyrosine phosphorylation plays a significant role in a wide range of cellular processes. The Drosophila genome encodes more than 20 receptor tyrosine kinases and extensive studies in the past 20 years have illustrated their diverse roles and complex signaling mechanisms. Although some receptor tyrosine kinases have highly specific functions, others strikingly are used in rather ubiquitous manners. Receptor tyrosine kinases regulate a broad expanse of processes, ranging from cell survival and proliferation to differentiation and patterning. Remarkably, different receptor tyrosine kinases share many of the same effectors and their hierarchical organization is retained in disparate biological contexts. In this comprehensive review, we summarize what is known regarding each receptor tyrosine kinase during Drosophila development. Astonishingly, very little is known for approximately half of all Drosophila receptor tyrosine kinases. PMID:23732470

  6. Live cell imaging in Drosophila melanogaster.

    PubMed

    Parton, Richard M; Vallés, Ana Maria; Dobbie, Ian M; Davis, Ilan

    2010-04-01

    Although many of the techniques of live cell imaging in Drosophila melanogaster are also used by the greater community of cell biologists working on other model systems, studying living fly tissues presents unique difficulties with regard to keeping the cells alive, introducing fluorescent probes, and imaging through thick, hazy cytoplasm. This article outlines the major tissue types amenable to study by time-lapse cinematography and different methods for keeping the cells alive. It describes various imaging and associated techniques best suited to following changes in the distribution of fluorescently labeled molecules in real time in these tissues. Imaging, in general, is a rapidly developing discipline, and recent advances in imaging technology are able to greatly extend what can be achieved with live cell imaging of Drosophila tissues. As far as possible, this article includes the latest technical developments and discusses likely future developments in imaging methods that could have an impact on research using Drosophila.

  7. Axon and dendrite pruning in Drosophila.

    PubMed

    Yu, Fengwei; Schuldiner, Oren

    2014-08-01

    Pruning, a process by which neurons selectively remove exuberant or unnecessary processes without causing cell death, is crucial for the establishment of mature neural circuits during animal development. Yet relatively little is known about molecular and cellular mechanisms that govern neuronal pruning. Holometabolous insects, such as Drosophila, undergo complete metamorphosis and their larval nervous systems are replaced with adult-specific ones, thus providing attractive models for studying neuronal pruning. Drosophila mushroom body and dendritic arborization neurons have been utilized as two appealing systems to elucidate the underlying mechanisms of axon and dendrite pruning, respectively. In this review we highlight recent developments and discuss some similarities and differences in the mechanisms that regulate these two distinct modes of neuronal pruning in Drosophila.

  8. Apoptosis in Drosophila: which role for mitochondria?

    PubMed

    Clavier, Amandine; Rincheval-Arnold, Aurore; Colin, Jessie; Mignotte, Bernard; Guénal, Isabelle

    2016-03-01

    It is now well established that the mitochondrion is a central regulator of mammalian cell apoptosis. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, mainly because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and cell death in Drosophila occurs at the mitochondrial level. Numerous proteins, including RHG proteins and proteins of the Bcl-2 family that are key regulators of Drosophila apoptosis, constitutively or transiently localize in mitochondria. These proteins participate in the cell death process at different levels such as degradation of Diap1, a Drosophila IAP, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. Here, we review these mitochondrial events that might have their counterpart in human.

  9. Developmental Toxicity Assays Using the Drosophila Model

    PubMed Central

    Rand, Matthew D.; Montgomery, Sara L.; Prince, Lisa; Vorojeikina, Daria

    2014-01-01

    The fruit fly (Drosophila melanogaster) has long been a premier model for developmental biologists and geneticists. The utility of Drosophila for toxicology studies has only recently gained broader recognition as a tool to elaborate molecular genetic mechanisms of toxic substances. In this article two practical applications of Drosophila for developmental toxicity assays are described. The first assay takes advantage of newly developed methods to render the fly embryo accessible to small molecules, toxicants and drugs. The second assay engages straightforward exposures to developing larvae and easy to score outcomes of adult development. With the extensive collections of flies that are publicly available and the ease with which to create transgenic flies, these two assays have a unique power for identifying and characterizing molecular mechanisms and cellular pathways specific to the mode of action of a number of toxicants and drugs. PMID:24789363

  10. [When Tribolium complements the genetics of Drosophila].

    PubMed

    Bonneton, François

    2010-03-01

    With its recently sequenced genome, the red flour beetle Tribolium castaneum became one of the few model organisms with all the main genetic tools. As a coleoptera, it belongs to the most species-rich order of animals. Tribolium is also a worldwide pest for stored dried foods. Regarding developmental biology, Tribolium offers a complementary model to the highly derived Drosophila. For example, the function of many gap and pair-rule segmentation genes is different in both species. These differences reveal the evolutionary plasticity between two modes of development, with a long germ band in fly and a short one in Tribolium. This beetle allowed the identification of a new type of ecdysone receptor for holometabolous insects. Finally, in the search for the juvenile hormone receptor, a crucial result was obtained with experiments that could be performed only with Tribolium, and not with Drosophila. Tribolium, in association with Drosophila, should help to understand the general rules of development in insects.

  11. Sexual Behavior of Drosophila suzukii

    PubMed Central

    Revadi, Santosh; Lebreton, Sébastien; Witzgall, Peter; Anfora, Gianfranco; Dekker, Teun; Becher, Paul G.

    2015-01-01

    A high reproductive potential is one reason for the rapid spread of Drosophila suzukii in Europe and in the United States. In order to identify mechanisms that mediate mating and reproduction in D. suzukii we studied the fly’s reproductive behavior, diurnal mating activity and sexual maturation. Furthermore, we studied the change of female cuticular hydrocarbons (CHCs) with age and conducted a preliminary investigation on the role of female-derived chemical signals in male mating behavior. Sexual behavior in D. suzukii is characterized by distinct elements of male courtship leading to female acceptance for mating. Time of day and age modulate D. suzukii mating activity. As with other drosophilids, female sexual maturity is paralleled by a quantitative increase in CHCs. Neither female CHCs nor other olfactory signals were required to induce male courtship, however, presence of those signals significantly increased male sexual behavior. With this pilot study we hope to stimulate research on the reproductive biology of D. suzukii, which is relevant for the development of pest management tools. PMID:26463074

  12. Flavin reduction activates Drosophila cryptochrome.

    PubMed

    Vaidya, Anand T; Top, Deniz; Manahan, Craig C; Tokuda, Joshua M; Zhang, Sheng; Pollack, Lois; Young, Michael W; Crane, Brian R

    2013-12-17

    Entrainment of circadian rhythms in higher organisms relies on light-sensing proteins that communicate to cellular oscillators composed of delayed transcriptional feedback loops. The principal photoreceptor of the fly circadian clock, Drosophila cryptochrome (dCRY), contains a C-terminal tail (CTT) helix that binds beside a FAD cofactor and is essential for light signaling. Light reduces the dCRY FAD to an anionic semiquinone (ASQ) radical and increases CTT proteolytic susceptibility but does not lead to CTT chemical modification. Additional changes in proteolytic sensitivity and small-angle X-ray scattering define a conformational response of the protein to light that centers at the CTT but also involves regions remote from the flavin center. Reduction of the flavin is kinetically coupled to CTT rearrangement. Chemical reduction to either the ASQ or the fully reduced hydroquinone state produces the same conformational response as does light. The oscillator protein Timeless (TIM) contains a sequence similar to the CTT; the corresponding peptide binds dCRY in light and protects the flavin from oxidation. However, TIM mutants therein still undergo dCRY-mediated degradation. Thus, photoreduction to the ASQ releases the dCRY CTT and promotes binding to at least one region of TIM. Flavin reduction by either light or cellular reductants may be a general mechanism of CRY activation.

  13. Flavin reduction activates Drosophila cryptochrome

    PubMed Central

    Vaidya, Anand T.; Top, Deniz; Manahan, Craig C.; Tokuda, Joshua M.; Zhang, Sheng; Pollack, Lois; Young, Michael W.; Crane, Brian R.

    2013-01-01

    Entrainment of circadian rhythms in higher organisms relies on light-sensing proteins that communicate to cellular oscillators composed of delayed transcriptional feedback loops. The principal photoreceptor of the fly circadian clock, Drosophila cryptochrome (dCRY), contains a C-terminal tail (CTT) helix that binds beside a FAD cofactor and is essential for light signaling. Light reduces the dCRY FAD to an anionic semiquinone (ASQ) radical and increases CTT proteolytic susceptibility but does not lead to CTT chemical modification. Additional changes in proteolytic sensitivity and small-angle X-ray scattering define a conformational response of the protein to light that centers at the CTT but also involves regions remote from the flavin center. Reduction of the flavin is kinetically coupled to CTT rearrangement. Chemical reduction to either the ASQ or the fully reduced hydroquinone state produces the same conformational response as does light. The oscillator protein Timeless (TIM) contains a sequence similar to the CTT; the corresponding peptide binds dCRY in light and protects the flavin from oxidation. However, TIM mutants therein still undergo dCRY-mediated degradation. Thus, photoreduction to the ASQ releases the dCRY CTT and promotes binding to at least one region of TIM. Flavin reduction by either light or cellular reductants may be a general mechanism of CRY activation. PMID:24297896

  14. Sexual Behavior of Drosophila suzukii.

    PubMed

    Revadi, Santosh; Lebreton, Sébastien; Witzgall, Peter; Anfora, Gianfranco; Dekker, Teun; Becher, Paul G

    2015-03-09

    A high reproductive potential is one reason for the rapid spread of Drosophila suzukii in Europe and in the United States. In order to identify mechanisms that mediate mating and reproduction in D. suzukii we studied the fly's reproductive behavior, diurnal mating activity and sexual maturation. Furthermore, we studied the change of female cuticular hydrocarbons (CHCs) with age and conducted a preliminary investigation on the role of female-derived chemical signals in male mating behavior. Sexual behavior in D. suzukii is characterized by distinct elements of male courtship leading to female acceptance for mating. Time of day and age modulate D. suzukii mating activity. As with other drosophilids, female sexual maturity is paralleled by a quantitative increase in CHCs. Neither female CHCs nor other olfactory signals were required to induce male courtship, however, presence of those signals significantly increased male sexual behavior. With this pilot study we hope to stimulate research on the reproductive biology of D. suzukii, which is relevant for the development of pest management tools.

  15. Drosophila melanogaster Models of Galactosemia.

    PubMed

    Daenzer, J M I; Fridovich-Keil, J L

    2017-01-01

    The galactosemias are a family of autosomal recessive genetic disorders resulting from impaired function of the Leloir pathway of galactose metabolism. Type I, or classic galactosemia, results from profound deficiency of galactose-1-phosphate uridylyltransferase, the second enzyme in the Leloir pathway. Type II galactosemia results from profound deficiency of galactokinase, the first enzyme in the Leloir pathway. Type III galactosemia results from partial deficiency of UDP galactose 4'-epimerase, the third enzyme in the Leloir pathway. Although at least classic galactosemia has been recognized clinically for more than 100 years, and detectable by newborn screening for more than 50 years, all three galactosemias remain poorly understood. Early detection and dietary restriction of galactose prevent neonatal lethality, but many affected infants grow to experience a broad range of developmental and other disabilities. To date, there is no intervention known that prevents or reverses these long-term complications. Drosophila melanogaster provides a genetically and biochemically facile model for these conditions, enabling studies that address mechanism and open the door for novel approaches to intervention.

  16. Evaluation of Traditional Medicines for Neurodegenerative Diseases Using Drosophila Models

    PubMed Central

    Lee, Soojin; Bang, Se Min; Lee, Joon Woo; Cho, Kyoung Sang

    2014-01-01

    Drosophila is one of the oldest and most powerful genetic models and has led to novel insights into a variety of biological processes. Recently, Drosophila has emerged as a model system to study human diseases, including several important neurodegenerative diseases. Because of the genomic similarity between Drosophila and humans, Drosophila neurodegenerative disease models exhibit a variety of human-disease-like phenotypes, facilitating fast and cost-effective in vivo genetic modifier screening and drug evaluation. Using these models, many disease-associated genetic factors have been identified, leading to the identification of compelling drug candidates. Recently, the safety and efficacy of traditional medicines for human diseases have been evaluated in various animal disease models. Despite the advantages of the Drosophila model, its usage in the evaluation of traditional medicines is only nascent. Here, we introduce the Drosophila model for neurodegenerative diseases and some examples demonstrating the successful application of Drosophila models in the evaluation of traditional medicines. PMID:24790636

  17. Monoclonal Antibodies against the Drosophila Nervous System

    NASA Astrophysics Data System (ADS)

    Fujita, Shinobu C.; Zipursky, Stephen L.; Benzer, Seymour; Ferrus, Alberto; Shotwell, Sandra L.

    1982-12-01

    A panel of 148 monoclonal antibodies directed against Drosophila neural antigens has been prepared by using mice immunized with homogenates of Drosophila tissue. Antibodies were screened immunohistochemically on cryostat sections of fly heads. A large diversity of staining patterns was observed. Some antigens were broadly distributed among tissues; others were highly specific to nerve fibers, neuropil, muscle, the tracheal system, cell nuclei, photoreceptors, or other structures. The antigens for many of the antibodies have been identified on immunoblots. Monoclonal antibodies that identify specific molecules within the nervous system should prove useful in the study of the molecular genetics of neural development.

  18. Genetics and neurobiology of aggression in Drosophila

    PubMed Central

    Zwarts, Liesbeth; Versteven, Marijke; Callaerts, Patrick

    2012-01-01

    Aggressive behavior is widely present throughout the animal kingdom and is crucial to ensure survival and reproduction. Aggressive actions serve to acquire territory, food, or mates and in defense against predators or rivals; while in some species these behaviors are involved in establishing a social hierarchy. Aggression is a complex behavior, influenced by a broad range of genetic and environmental factors. Recent studies in Drosophila provide insight into the genetic basis and control of aggression. The state of the art on aggression in Drosophila and the many opportunities provided by this model organism to unravel the genetic and neurobiological basis of aggression are reviewed. PMID:22513455

  19. Developing a Drosophila Model of Schwannomatosis

    DTIC Science & Technology

    2012-08-01

    found to associate with RasV12;scrib–/– tumors and to reduce tumor growth in scrib–/– animals (Pastor- Pareja et al., 2008). The Drosophila genome...2006). Loss of cell polarity drives tumor growth and invasion through JNK activation in Drosophila. Curr. Biol. 16, 1139-1146. Igaki, T., Pastor- Pareja ...genome. Nat. Genet. 36, 288-292. Pastor- Pareja , J. C., Wu, M. and Xu. T. (2008). An innate immune response of blood cells to tumors and tissue damage in

  20. Asymmetric stem cell division: lessons from Drosophila.

    PubMed

    Wu, Pao-Shu; Egger, Boris; Brand, Andrea H

    2008-06-01

    Asymmetric cell division is an important and conserved strategy in the generation of cellular diversity during animal development. Many of our insights into the underlying mechanisms of asymmetric cell division have been gained from Drosophila, including the establishment of polarity, orientation of mitotic spindles and segregation of cell fate determinants. Recent studies are also beginning to reveal the connection between the misregulation of asymmetric cell division and cancer. What we are learning from Drosophila as a model system has implication both for stem cell biology and also cancer research.

  1. Symmetry Breaking During Drosophila Oogenesis

    PubMed Central

    Roth, Siegfried; Lynch, Jeremy A.

    2009-01-01

    The orthogonal axes of Drosophila are established during oogenesis through a hierarchical series of symmetry-breaking steps, most of which can be traced back to asymmetries inherent in the architecture of the ovary. Oogenesis begins with the formation of a germline cyst of 16 cells connected by ring canals. Two of these 16 cells have four ring canals, whereas the others have fewer. The first symmetry-breaking step is the selection of one of these two cells to become the oocyte. Subsequently, the germline cyst becomes surrounded by somatic follicle cells to generate individual egg chambers. The second symmetry-breaking step is the posterior positioning of the oocyte within the egg chamber, a process mediated by adhesive interactions with a special group of somatic cells. Posterior oocyte positioning is accompanied by a par gene-dependent repolarization of the microtubule network, which establishes the posterior cortex of the oocyte. The next two steps of symmetry breaking occur during midoogenesis after the volume of the oocyte has increased about 10-fold. First, a signal from the oocyte specifies posterior follicle cells, polarizing a symmetric prepattern present within the follicular epithelium. Second, the posterior follicle cells send a signal back to the oocyte, which leads to a second repolarization of the oocyte microtubule network and the asymmetric migration of the oocyte nucleus. This process again requires the par genes. The repolarization of the microtubule network results in the transport of bicoid and oskar mRNAs, the anterior and posterior determinants, respectively, of the embryonic axis, to opposite poles of the oocyte. The asymmetric positioning of the oocyte nucleus defines a cortical region of the oocyte where gurken mRNA is localized, thus breaking the dorsal–ventral symmetry of the egg and embryo. PMID:20066085

  2. Antigenotoxicity studies in Drosophila melanogaster.

    PubMed

    Graf, U; Abraham, S K; Guzmán-Rincón, J; Würgler, F E

    1998-06-18

    The fruit fly Drosophila melangaster with its well developed array of genotoxicity test systems has been used in a number of studies on antigenotoxicity of various compounds and mixtures. In recent years, the newly developed Somatic Mutation and Recombination Tests (SMART) have mainly been employed. These one-generation tests make use of the wing or eye imaginal disc cells in larvae and have proven to be very efficient and sensitive. They are based on the principle that the loss of heterozygosity of suitable recessive markers can lead to the formation of mutant clones of cells that are then expressed as spots on the wings or eyes of the adult flies. We have employed the wing spot test with the two markers multiple wing hairs (mwh,3-0.3) and flare (flr,3-38.8). Three-day-old larvae, trans-heterozygous for these markers, are treated chronically or acutely by oral administration with the test compound(s) or complex mixtures. For antigenotoxicity studies, chronic co-treatments can be used, as well as separate pre-treatments with an antigenotoxic agent followed by a chronic treatment with a genotoxin. After eclosion, the wings of the adult flies are scored for the presence of single and twin spots. These spots can be due to different genotoxic events: either mitotic recombination or mutation (deletion, point mutation, specific types of translocation, etc.). The analysis of two different genotypes (one with structurally normal chromosomes, one with a multiply inverted balancer chromosome) allows for a quantitative determination of the recombinagenic activity of genotoxins. Results of two separate studies presented: (1) instant coffee has antirecombinagenic but not antimutagenic activity in the wing spot test; and (2) ascorbic acid and catechin are able to protect against in vivo nitrosation products of methyl urea in combination with sodium nitrite.

  3. Signaling by Drosophila capa neuropeptides.

    PubMed

    Davies, Shireen-A; Cabrero, Pablo; Povsic, Manca; Johnston, Natalie R; Terhzaz, Selim; Dow, Julian A T

    2013-07-01

    The capa peptide family, originally identified in the tobacco hawk moth, Manduca sexta, is now known to be present in many insect families, with increasing publications on capa neuropeptides each year. The physiological actions of capa peptides vary depending on the insect species but capa peptides have key myomodulatory and osmoregulatory functions, depending on insect lifestyle, and life stage. Capa peptide signaling is thus critical for fluid homeostasis and survival, making study of this neuropeptide family attractive for novel routes for insect control. In Dipteran species, including the genetically tractable Drosophila melanogaster, capa peptide action is diuretic; via elevation of nitric oxide, cGMP and calcium in the principal cells of the Malpighian tubules. The identification of the capa receptor (capaR) in several insect species has shown this to be a canonical GPCR. In D. melanogaster, ligand-activated capaR activity occurs in a dose-dependent manner between 10(-6) and 10(-12)M. Lower concentrations of capa peptide do not activate capaR, either in adult or larval Malpighian tubules. Use of transgenic flies in which capaR is knocked-down in only Malpighian tubule principal cells demonstrates that capaR modulates tubule fluid secretion rates and in doing so, sets the organismal response to desiccation. Thus, capa regulates a desiccation-responsive pathway in D. melanogaster, linking its role in osmoregulation and fluid homeostasis to environmental response and survival. The conservation of capa action between some Dipteran species suggests that capa's role in desiccation tolerance may not be confined to D. melanogaster.

  4. Drosophila Bitter Taste(s)

    PubMed Central

    French, Alice; Ali Agha, Moutaz; Mitra, Aniruddha; Yanagawa, Aya; Sellier, Marie-Jeanne; Marion-Poll, Frédéric

    2015-01-01

    Most animals possess taste receptors neurons detecting potentially noxious compounds. In humans, the ligands which activate these neurons define a sensory space called “bitter”. By extension, this term has been used in animals and insects to define molecules which induce aversive responses. In this review, based on our observations carried out in Drosophila, we examine how bitter compounds are detected and if bitter-sensitive neurons respond only to molecules bitter to humans. Like most animals, flies detect bitter chemicals through a specific population of taste neurons, distinct from those responding to sugars or to other modalities. Activating bitter-sensitive taste neurons induces aversive reactions and inhibits feeding. Bitter molecules also contribute to the suppression of sugar-neuron responses and can lead to a complete inhibition of the responses to sugar at the periphery. Since some bitter molecules activate bitter-sensitive neurons and some inhibit sugar detection, bitter molecules are represented by two sensory spaces which are only partially congruent. In addition to molecules which impact feeding, we recently discovered that the activation of bitter-sensitive neurons also induces grooming. Bitter-sensitive neurons of the wings and of the legs can sense chemicals from the gram negative bacteria, Escherichia coli, thus adding another biological function to these receptors. Bitter-sensitive neurons of the proboscis also respond to the inhibitory pheromone, 7-tricosene. Activating these neurons by bitter molecules in the context of sexual encounter inhibits courting and sexual reproduction, while activating these neurons with 7-tricosene in a feeding context will inhibit feeding. The picture that emerges from these observations is that the taste system is composed of detectors which monitor different “categories” of ligands, which facilitate or inhibit behaviors depending on the context (feeding, sexual reproduction, hygienic behavior), thus

  5. Functional Neuroanatomy of "Drosophila" Olfactory Memory Formation

    ERIC Educational Resources Information Center

    Guven-Ozkan, Tugba; Davis, Ronald L.

    2014-01-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying "Drosophila" learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive…

  6. Organization of descending neurons in Drosophila melanogaster.

    PubMed

    Hsu, Cynthia T; Bhandawat, Vikas

    2016-02-03

    Neural processing in the brain controls behavior through descending neurons (DNs) - neurons which carry signals from the brain to the spinal cord (or thoracic ganglia in insects). Because DNs arise from multiple circuits in the brain, the numerical simplicity and availability of genetic tools make Drosophila a tractable model for understanding descending motor control. As a first step towards a comprehensive study of descending motor control, here we estimate the number and distribution of DNs in the Drosophila brain. We labeled DNs by backfilling them with dextran dye applied to the neck connective and estimated that there are ~1100 DNs distributed in 6 clusters in Drosophila. To assess the distribution of DNs by neurotransmitters, we labeled DNs in flies in which neurons expressing the major neurotransmitters were also labeled. We found DNs belonging to every neurotransmitter class we tested: acetylcholine, GABA, glutamate, serotonin, dopamine and octopamine. Both the major excitatory neurotransmitter (acetylcholine) and the major inhibitory neurotransmitter (GABA) are employed equally; this stands in contrast to vertebrate DNs which are predominantly excitatory. By comparing the distribution of DNs in Drosophila to those reported previously in other insects, we conclude that the organization of DNs in insects is highly conserved.

  7. Drosophila Melanogaster as an Experimental Organism.

    ERIC Educational Resources Information Center

    Rubin, Gerald M.

    1988-01-01

    Discusses the role of the fruit fly in genetics research requiring a multidisciplinary approach. Describes embryological and genetic methods used in the experimental analysis of this organism. Outlines the use of Drosophila in the study of the development and function of the nervous system. (RT)

  8. Isolation of Drosophila egg chambers for imaging.

    PubMed

    Parton, Richard M; Vallés, Ana Maria; Dobbie, Ian M; Davis, Ilan

    2010-04-01

    The fruit fly Drosophila melanogaster is an important model for basic research into the molecular mechanisms underlying cell function and development, as well as a major biomedical research tool. A significant advantage of Drosophila is the ability to apply live cell imaging to a variety of living tissues that can be dissected and imaged in vivo, ex vivo, or in vitro. Drosophila egg chambers, for example, have proven to be a useful model system for studying border cell migration, Golgi unit transport, the rapid movement of mRNA and protein particles, and the role of microtubules in meiosis and oocyte differentiation. A crucial first step before imaging is preparation of the experimental material to ensure physiological relevance and to achieve the best conditions for image quality. Early- to mid-stage egg chambers cannot be mounted in an aqueous-based medium, because this causes a change in microtubule organization and follicle cell morphology. Such egg chambers survive better in Halocarbon oil, which allows free diffusion of oxygen, has low viscosity, and thus prevents dehydration and hypoxia. With a refractive index similar to glycerol, Halocarbon oil also has good optical properties for imaging. It also provides a good environment for injection and is particularly useful for long-term imaging of embryos. However, unlike with aqueous solutions, changes in the medium are not possible. This protocol describes the isolation of Drosophila egg chambers.

  9. Measurement of Cytoplasmic Streaming in Drosophila Melanogaster

    NASA Astrophysics Data System (ADS)

    Ganguly, Sujoy; Williams, Lucy; Palacios, Isabel; Goldstein, Raymond

    2010-11-01

    During stage 9 of Drosophila melanogastor oogenesis flow of the oocyte cytoplasm, driven by kinesin 1 motor protein is observed. This cytoplasmic streaming is analyzed by PIV in both wild type and kinesin light chain mutants, revealing striking statistical differences. Further measurements of the rheology of the oocyte allow for estimations of the mechanical energy needed to generate the observed flows.

  10. Mechanisms of nondisjunction induction in drosophila oocytes.

    PubMed

    Leigh, B

    1979-08-01

    Quantitative and qualitative studies on the induction of no-disjunction and related phenomena can be carried out using the germ cells of Drosophila. X-Irradiation breaks chromosomes and cold-shock disrupts spindles, these two treatments producing different spectra of nondisjunction in oocytes.

  11. Open-Ended Laboratory Investigations with Drosophila.

    ERIC Educational Resources Information Center

    Mertens, Thomas R.

    1983-01-01

    Background information, laboratory procedures (including matings performed), and results are presented for an open-ended investigation using the fruitfly Drosophila melanogaster. Once data are collected, students develop hypotheses to explain results as well as devise additional experiments to test their hypotheses. Calculation of chi-square for…

  12. Second-Order Conditioning in "Drosophila"

    ERIC Educational Resources Information Center

    Tabone, Christopher J.; de Belle, J. Steven

    2011-01-01

    Associative conditioning in "Drosophila melanogaster" has been well documented for several decades. However, most studies report only simple associations of conditioned stimuli (CS, e.g., odor) with unconditioned stimuli (US, e.g., electric shock) to measure learning or establish memory. Here we describe a straightforward second-order conditioning…

  13. The taste response to ammonia in Drosophila

    PubMed Central

    Delventhal, R.; Menuz, K.; Joseph, R.; Park, J.; Sun, J. S.; Carlson, J. R.

    2017-01-01

    Ammonia is both a building block and a breakdown product of amino acids and is found widely in the environment. The odor of ammonia is attractive to many insects, including insect vectors of disease. The olfactory response of Drosophila to ammonia has been studied in some detail, but the taste response has received remarkably little attention. Here, we show that ammonia is a taste cue for Drosophila. Nearly all sensilla of the major taste organ of the Drosophila head house a neuron that responds to neutral solutions of ammonia. Ammonia is toxic at high levels to many organisms, and we find that it has a negative valence in two paradigms of taste behavior, one operating over hours and the other over seconds. Physiological and behavioral responses to ammonia depend at least in part on Gr66a+ bitter-sensing taste neurons, which activate a circuit that deters feeding. The Amt transporter, a critical component of olfactory responses to ammonia, is widely expressed in taste neurons but is not required for taste responses. This work establishes ammonia as an ecologically important taste cue in Drosophila, and shows that it can activate circuits that promote opposite behavioral outcomes via different sensory systems. PMID:28262698

  14. Organization of descending neurons in Drosophila melanogaster

    PubMed Central

    Hsu, Cynthia T.; Bhandawat, Vikas

    2016-01-01

    Neural processing in the brain controls behavior through descending neurons (DNs) - neurons which carry signals from the brain to the spinal cord (or thoracic ganglia in insects). Because DNs arise from multiple circuits in the brain, the numerical simplicity and availability of genetic tools make Drosophila a tractable model for understanding descending motor control. As a first step towards a comprehensive study of descending motor control, here we estimate the number and distribution of DNs in the Drosophila brain. We labeled DNs by backfilling them with dextran dye applied to the neck connective and estimated that there are ~1100 DNs distributed in 6 clusters in Drosophila. To assess the distribution of DNs by neurotransmitters, we labeled DNs in flies in which neurons expressing the major neurotransmitters were also labeled. We found DNs belonging to every neurotransmitter class we tested: acetylcholine, GABA, glutamate, serotonin, dopamine and octopamine. Both the major excitatory neurotransmitter (acetylcholine) and the major inhibitory neurotransmitter (GABA) are employed equally; this stands in contrast to vertebrate DNs which are predominantly excitatory. By comparing the distribution of DNs in Drosophila to those reported previously in other insects, we conclude that the organization of DNs in insects is highly conserved. PMID:26837716

  15. Genomics of Ecological Adaptation in Cactophilic Drosophila

    PubMed Central

    Guillén, Yolanda; Rius, Núria; Delprat, Alejandra; Williford, Anna; Muyas, Francesc; Puig, Marta; Casillas, Sònia; Ràmia, Miquel; Egea, Raquel; Negre, Barbara; Mir, Gisela; Camps, Jordi; Moncunill, Valentí; Ruiz-Ruano, Francisco J.; Cabrero, Josefa; de Lima, Leonardo G.; Dias, Guilherme B.; Ruiz, Jeronimo C.; Kapusta, Aurélie; Garcia-Mas, Jordi; Gut, Marta; Gut, Ivo G.; Torrents, David; Camacho, Juan P.; Kuhn, Gustavo C.S.; Feschotte, Cédric; Clark, Andrew G.; Betrán, Esther; Barbadilla, Antonio; Ruiz, Alfredo

    2015-01-01

    Cactophilic Drosophila species provide a valuable model to study gene–environment interactions and ecological adaptation. Drosophila buzzatii and Drosophila mojavensis are two cactophilic species that belong to the repleta group, but have very different geographical distributions and primary host plants. To investigate the genomic basis of ecological adaptation, we sequenced the genome and developmental transcriptome of D. buzzatii and compared its gene content with that of D. mojavensis and two other noncactophilic Drosophila species in the same subgenus. The newly sequenced D. buzzatii genome (161.5 Mb) comprises 826 scaffolds (>3 kb) and contains 13,657 annotated protein-coding genes. Using RNA sequencing data of five life-stages we found expression of 15,026 genes, 80% protein-coding genes, and 20% noncoding RNA genes. In total, we detected 1,294 genes putatively under positive selection. Interestingly, among genes under positive selection in the D. mojavensis lineage, there is an excess of genes involved in metabolism of heterocyclic compounds that are abundant in Stenocereus cacti and toxic to nonresident Drosophila species. We found 117 orphan genes in the shared D. buzzatii–D. mojavensis lineage. In addition, gene duplication analysis identified lineage-specific expanded families with functional annotations associated with proteolysis, zinc ion binding, chitin binding, sensory perception, ethanol tolerance, immunity, physiology, and reproduction. In summary, we identified genetic signatures of adaptation in the shared D. buzzatii–D. mojavensis lineage, and in the two separate D. buzzatii and D. mojavensis lineages. Many of the novel lineage-specific genomic features are promising candidates for explaining the adaptation of these species to their distinct ecological niches. PMID:25552534

  16. Optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Alex, Aneesh; Li, Airong; Men, Jing; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2016-03-01

    A non-invasive, contact-less cardiac pacing technology can be a powerful tool in basic cardiac research and in clinics. Currently, electrical pacing is the gold standard for cardiac pacing. Although highly effective in controlling the cardiac function, the invasive nature, non-specificity to cardiac tissues and possible tissue damage limits its capabilities. Optical pacing of heart is a promising alternative, which is non-invasive and more specific, has high spatial and temporal precision, and avoids shortcomings in electrical stimulation. Optical coherence tomography has been proved to be an effective technique in non-invasive imaging in vivo with ultrahigh resolution and imaging speed. In the last several years, non-invasive specific optical pacing in animal hearts has been reported in quail, zebrafish, and rabbit models. However, Drosophila Melanogaster, which is a significant model with orthologs of 75% of human disease genes, has rarely been studied concerning their optical pacing in heart. Here, we combined optogenetic control of Drosophila heartbeat with optical coherence microscopy (OCM) technique for the first time. The light-gated cation channel, channelrhodopsin-2 (ChR2) was specifically expressed by transgene as a pacemaker in drosophila heart. By stimulating the pacemaker with 472 nm pulsed laser light at different frequencies, we achieved non-invasive and more specific optical control of the Drosophila heart rhythm, which demonstrates the wide potential of optical pacing for studying cardiac dynamics and development. Imaging capability of our customized OCM system was also involved to observe the pacing effect visually. No tissue damage was found after long exposure to laser pulses, which proved the safety of optogenetic control of Drosophila heart.

  17. FlyBase: the Drosophila database. The Flybase Consortium.

    PubMed Central

    1996-01-01

    FlyBase is a database of genetic and molecular data concerning Drosophila. FlyBase is maintained as a relational database (in Sybase). The scope of FlyBase includes: genes, alleles (and phenotypes), aberrations, pointers to sequence data, clones, stock lists, Drosophila workers and bibliographic references. FlyBase is also available on CD-ROM for Macintosh systems (Encyclopaedia of Drosophila). PMID:8594600

  18. [Research progress of transgenic Drosophila model of Alzheimer disease].

    PubMed

    Tan, Yan; Ji, Yu-Bin; Zhao, Jian

    2013-03-01

    Alzheimer disease (AD) is a common neurodegenerative disease. Drosophila has been regard as one of the ideal models for Alzheimer because of its unique advantage on genetic manipulation. AD transgenic drosophila models not only help to elucidate the pathogenesis of Alzheimer disease, but also provide potential screening models for drugs to treat the disease. In this review, we summarize the recent research progress using AD transgenic drosophila.

  19. The first complete Mag family retrotransposons discovered in Drosophila.

    PubMed

    Glukhov, I A; Kotnova, A P; Stefanov, Y E; Ilyin, Y V

    2016-01-01

    A retrotransposon of the Mag family was found in the Drosophila simulans genome for the first time. We also identified novel transposable elements representing the Mag family in seven Drosophila species. The high similarity between the 3' and 5' long terminal repeats in the found copies of transposable elements indicates that their retrotransposition has occurred relatively recently. Thus, the Mag family of retrotransposons is quite common for the genus Drosophila.

  20. Heat shock proteins and Drosophila aging

    PubMed Central

    Tower, John

    2010-01-01

    Since their discovery in Drosophila, the heat shock proteins (Hsps) have been shown to regulate both stress resistance and life span. Aging is characterized by increased oxidative stress and the accumulation of abnormal (malfolded) proteins, and these stresses induce Hsp gene expression through the transcription factor HSF. In addition, a subset of Hsps is induced by oxidative stress through the JNK signaling pathway and the transcription factor Foxo. The Hsps counteract the toxicity of abnormal proteins by facilitating protein refolding and turnover, and through other mechanisms including inhibition of apoptosis. The Hsps are up-regulated in tissue-specific patterns during aging, and their expression correlates with, and sometimes predicts, life span, making them ideal biomarkers of aging. The tools available for experimentally manipulating gene function and assaying healthspan in Drosophila provides an unparalleled opportunity to further study the role of Hsps in aging. PMID:20840862

  1. The translation factors of Drosophila melanogaster

    PubMed Central

    Marygold, Steven J.; Attrill, Helen; Lasko, Paul

    2017-01-01

    ABSTRACT Synthesis of polypeptides from mRNA (translation) is a fundamental cellular process that is coordinated and catalyzed by a set of canonical ‘translation factors’. Surprisingly, the translation factors of Drosophila melanogaster have not yet been systematically identified, leading to inconsistencies in their nomenclature and shortcomings in functional (Gene Ontology, GO) annotations. Here, we describe the complete set of translation factors in D. melanogaster, applying nomenclature already in widespread use in other species, and revising their functional annotation. The collection comprises 43 initiation factors, 12 elongation factors, 3 release factors and 6 recycling factors, totaling 64 of which 55 are cytoplasmic and 9 are mitochondrial. We also provide an overview of notable findings and particular insights derived from Drosophila about these factors. This catalog, together with the incorporation of the improved nomenclature and GO annotation into FlyBase, will greatly facilitate access to information about the functional roles of these important proteins. PMID:27494710

  2. Development of larval motor circuits in Drosophila.

    PubMed

    Kohsaka, Hiroshi; Okusawa, Satoko; Itakura, Yuki; Fushiki, Akira; Nose, Akinao

    2012-04-01

    How are functional neural circuits formed during development? Despite recent advances in our understanding of the development of individual neurons, little is known about how complex circuits are assembled to generate specific behaviors. Here, we describe the ways in which Drosophila motor circuits serve as an excellent model system to tackle this problem. We first summarize what has been learned during the past decades on the connectivity and development of component neurons, in particular motor neurons and sensory feedback neurons. We then review recent progress in our understanding of the development of the circuits as well as studies that apply optogenetics and other innovative techniques to dissect the circuit diagram. New approaches using Drosophila as a model system are now making it possible to search for developmental rules that regulate the construction of neural circuits.

  3. Quantifying and predicting Drosophila larvae crawling phenotypes

    PubMed Central

    Günther, Maximilian N.; Nettesheim, Guilherme; Shubeita, George T.

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  4. The genome sequence of Drosophila melanogaster.

    PubMed

    Adams, M D; Celniker, S E; Holt, R A; Evans, C A; Gocayne, J D; Amanatides, P G; Scherer, S E; Li, P W; Hoskins, R A; Galle, R F; George, R A; Lewis, S E; Richards, S; Ashburner, M; Henderson, S N; Sutton, G G; Wortman, J R; Yandell, M D; Zhang, Q; Chen, L X; Brandon, R C; Rogers, Y H; Blazej, R G; Champe, M; Pfeiffer, B D; Wan, K H; Doyle, C; Baxter, E G; Helt, G; Nelson, C R; Gabor, G L; Abril, J F; Agbayani, A; An, H J; Andrews-Pfannkoch, C; Baldwin, D; Ballew, R M; Basu, A; Baxendale, J; Bayraktaroglu, L; Beasley, E M; Beeson, K Y; Benos, P V; Berman, B P; Bhandari, D; Bolshakov, S; Borkova, D; Botchan, M R; Bouck, J; Brokstein, P; Brottier, P; Burtis, K C; Busam, D A; Butler, H; Cadieu, E; Center, A; Chandra, I; Cherry, J M; Cawley, S; Dahlke, C; Davenport, L B; Davies, P; de Pablos, B; Delcher, A; Deng, Z; Mays, A D; Dew, I; Dietz, S M; Dodson, K; Doup, L E; Downes, M; Dugan-Rocha, S; Dunkov, B C; Dunn, P; Durbin, K J; Evangelista, C C; Ferraz, C; Ferriera, S; Fleischmann, W; Fosler, C; Gabrielian, A E; Garg, N S; Gelbart, W M; Glasser, K; Glodek, A; Gong, F; Gorrell, J H; Gu, Z; Guan, P; Harris, M; Harris, N L; Harvey, D; Heiman, T J; Hernandez, J R; Houck, J; Hostin, D; Houston, K A; Howland, T J; Wei, M H; Ibegwam, C; Jalali, M; Kalush, F; Karpen, G H; Ke, Z; Kennison, J A; Ketchum, K A; Kimmel, B E; Kodira, C D; Kraft, C; Kravitz, S; Kulp, D; Lai, Z; Lasko, P; Lei, Y; Levitsky, A A; Li, J; Li, Z; Liang, Y; Lin, X; Liu, X; Mattei, B; McIntosh, T C; McLeod, M P; McPherson, D; Merkulov, G; Milshina, N V; Mobarry, C; Morris, J; Moshrefi, A; Mount, S M; Moy, M; Murphy, B; Murphy, L; Muzny, D M; Nelson, D L; Nelson, D R; Nelson, K A; Nixon, K; Nusskern, D R; Pacleb, J M; Palazzolo, M; Pittman, G S; Pan, S; Pollard, J; Puri, V; Reese, M G; Reinert, K; Remington, K; Saunders, R D; Scheeler, F; Shen, H; Shue, B C; Sidén-Kiamos, I; Simpson, M; Skupski, M P; Smith, T; Spier, E; Spradling, A C; Stapleton, M; Strong, R; Sun, E; Svirskas, R; Tector, C; Turner, R; Venter, E; Wang, A H; Wang, X; Wang, Z Y; Wassarman, D A; Weinstock, G M; Weissenbach, J; Williams, S M; WoodageT; Worley, K C; Wu, D; Yang, S; Yao, Q A; Ye, J; Yeh, R F; Zaveri, J S; Zhan, M; Zhang, G; Zhao, Q; Zheng, L; Zheng, X H; Zhong, F N; Zhong, W; Zhou, X; Zhu, S; Zhu, X; Smith, H O; Gibbs, R A; Myers, E W; Rubin, G M; Venter, J C

    2000-03-24

    The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

  5. Transcriptional Memory in the Drosophila Embryo.

    PubMed

    Ferraro, Teresa; Esposito, Emilia; Mancini, Laure; Ng, Sam; Lucas, Tanguy; Coppey, Mathieu; Dostatni, Nathalie; Walczak, Aleksandra M; Levine, Michael; Lagha, Mounia

    2016-01-25

    Transmission of active transcriptional states from mother to daughter cells has the potential to foster precision in the gene expression programs underlying development. Such transcriptional memory has been specifically proposed to promote rapid reactivation of complex gene expression profiles after successive mitoses in Drosophila development [1]. By monitoring transcription in living Drosophila embryos, we provide the first evidence for transcriptional memory in animal development. We specifically monitored the activities of stochastically expressed transgenes in order to distinguish active and inactive mother cells and the behaviors of their daughter nuclei after mitosis. Quantitative analyses reveal that there is a 4-fold higher probability for rapid reactivation after mitosis when the mother experienced transcription. Moreover, memory nuclei activate transcription twice as fast as neighboring inactive mothers, thus leading to augmented levels of gene expression. We propose that transcriptional memory is a mechanism of precision, which helps coordinate gene activity during embryogenesis.

  6. Death Valley, Drosophila, and the Devonian toolkit.

    PubMed

    Dickinson, Michael H

    2014-01-01

    Most experiments on the flight behavior of Drosophila melanogaster have been performed within confined laboratory chambers, yet the natural history of these animals involves dispersal that takes place on a much larger spatial scale. Thirty years ago, a group of population geneticists performed a series of mark-and-recapture experiments on Drosophila flies, which demonstrated that even cosmopolitan species are capable of covering 10 km of open desert, probably in just a few hours and without the possibility of feeding along the way. In this review I revisit these fascinating and informative experiments and attempt to explain how-from takeoff to landing-the flies might have made these journeys based on our current knowledge of flight behavior. This exercise provides insight into how animals generate long behavioral sequences using sensory-motor modules that may have an ancient evolutionary origin.

  7. Ultrastructural Analysis of Myoblast Fusion in Drosophila

    PubMed Central

    Zhang, Shiliang; Chen, Elizabeth H.

    2015-01-01

    Summary Myoblast fusion in Drosophila has become a powerful genetic system with which to unravel the mechanisms underlying cell fusion. The identification of important components of myoblast fusion by genetic analysis has led to a molecular pathway toward our understanding of this cellular process. In addition to the application of immunohistochemistry and live imaging techniques to visualize myoblast fusion at the light microscopic level, ultrastructural analysis using electron microscopy remains an indispensable tool to reveal fusion intermediates and specific membrane events at sites of fusion. In this chapter, we describe conventional chemical fixation and high-pressure freezing/freeze substitution methods for visualizing fusion intermediates during Drosophila myoblast fusion. Furthermore, we describe an immunoelectron microscopic method for localizing specific proteins relative to the fusion apparatus. PMID:18979250

  8. A Drosophila model for alcohol reward.

    PubMed

    Kaun, Karla R; Azanchi, Reza; Maung, Zaw; Hirsh, Jay; Heberlein, Ulrike

    2011-05-01

    The rewarding properties of drugs contribute to the development of abuse and addiction. We developed a new assay for investigating the motivational properties of ethanol in the genetically tractable model Drosophila melanogaster. Flies learned to associate cues with ethanol intoxication and, although transiently aversive, the experience led to a long-lasting attraction for the ethanol-paired cue, implying that intoxication is rewarding. Temporally blocking transmission in dopaminergic neurons revealed that flies require activation of these neurons to express, but not develop, conditioned preference for ethanol-associated cues. Moreover, flies acquired, consolidated and retrieved these rewarding memories using distinct sets of neurons in the mushroom body. Finally, mutations in scabrous, encoding a fibrinogen-related peptide that regulates Notch signaling, disrupted the formation of memories for ethanol reward. Our results thus establish that Drosophila can be useful for understanding the molecular, genetic and neural mechanisms underling the rewarding properties of ethanol.

  9. Studying circadian rhythms in Drosophila melanogaster

    PubMed Central

    Tataroglu, Ozgur; Emery, Patrick

    2014-01-01

    Circadian rhythms have a profound influence on most bodily functions: from metabolism to complex behaviors. They ensure that all these biological processes are optimized with the time-of-day. They are generated by endogenous molecular oscillators that have a period that closely, but not exactly, matches day length. These molecular clocks are synchronized by environmental cycles such as light intensity and temperature. Drosophila melanogaster has been a model organism of choice to understand genetically, molecularly and at the level of neural circuits how circadian rhythms are generated, how they are synchronized by environmental cues, and how they drive behavioral cycles such as locomotor rhythms. This review will cover a wide range of techniques that have been instrumental to our understanding of Drosophila circadian rhythms, and that are essential for current and future research. PMID:24412370

  10. Remembering Components of Food in Drosophila

    PubMed Central

    Das, Gaurav; Lin, Suewei; Waddell, Scott

    2016-01-01

    Remembering features of past feeding experience can refine foraging and food choice. Insects can learn to associate sensory cues with components of food, such as sugars, amino acids, water, salt, alcohol, toxins and pathogens. In the fruit fly Drosophila some food components activate unique subsets of dopaminergic neurons (DANs) that innervate distinct functional zones on the mushroom bodies (MBs). This architecture suggests that the overall dopaminergic neuron population could provide a potential cellular substrate through which the fly might learn to value a variety of food components. In addition, such an arrangement predicts that individual component memories reside in unique locations. DANs are also critical for food memory consolidation and deprivation-state dependent motivational control of the expression of food-relevant memories. Here, we review our current knowledge of how nutrient-specific memories are formed, consolidated and specifically retrieved in insects, with a particular emphasis on Drosophila. PMID:26924969

  11. Counting calories in Drosophila diet restriction.

    PubMed

    Min, Kyung-Jin; Flatt, Thomas; Kulaots, Indrek; Tatar, Marc

    2007-03-01

    The extension of life span by diet restriction in Drosophila has been argued to occur without limiting calories. Here we directly measure the calories assimilated by flies when maintained on full- and restricted-diets. We find that caloric intake is reduced on all diets that extend life span. Flies on low-yeast diet are long-lived and consume about half the calories of flies on high-yeast diets, regardless of the energetic content of the diet itself. Since caloric intake correlates with yeast concentration and thus with the intake of every metabolite in this dietary component, it is premature to conclude for Drosophila that calories do not explain extension of life span.

  12. Maintenance of a Drosophila melanogaster Population Cage.

    PubMed

    Caravaca, Juan Manuel; Lei, Elissa P

    2016-03-15

    Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle.

  13. Peptidoglycan recognition proteins in Drosophila immunity

    PubMed Central

    Kurata, Shoichiro

    2013-01-01

    Innate immunity is the front line of self-defense against infectious non-self in vertebrates and invertebrates. The innate immune system is mediated by germ-line encoding pattern recognition molecules (pathogen sensors) that recognize conserved molecular patterns present in the pathogens but absent in the host. Peptidoglycans (PGN) are essential cell wall components of almost all bacteria, except mycoplasma lacking a cell wall, which provides the host immune system an advantage for detecting invading bacteria. Several families of pattern recognition molecules that detect PGN and PGN-derived compounds have been indentified, and the role of PGRP family members in host defense is relatively well-chacterized in Drosophila. This review focuses on the role of PGRP family members in the recognition of invading bacteria and the activation and modulation of immune responses in Drosophila. PMID:23796791

  14. Studying circadian rhythms in Drosophila melanogaster.

    PubMed

    Tataroglu, Ozgur; Emery, Patrick

    2014-06-15

    Circadian rhythms have a profound influence on most bodily functions: from metabolism to complex behaviors. They ensure that all these biological processes are optimized with the time-of-day. They are generated by endogenous molecular oscillators that have a period that closely, but not exactly, matches day length. These molecular clocks are synchronized by environmental cycles such as light intensity and temperature. Drosophila melanogaster has been a model organism of choice to understand genetically, molecularly and at the level of neural circuits how circadian rhythms are generated, how they are synchronized by environmental cues, and how they drive behavioral cycles such as locomotor rhythms. This review will cover a wide range of techniques that have been instrumental to our understanding of Drosophila circadian rhythms, and that are essential for current and future research.

  15. Maintenance of a Drosophila melanogaster Population Cage

    PubMed Central

    Caravaca, Juan Manuel; Lei, Elissa P.

    2016-01-01

    Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle. PMID:27023790

  16. Quantifying and predicting Drosophila larvae crawling phenotypes.

    PubMed

    Günther, Maximilian N; Nettesheim, Guilherme; Shubeita, George T

    2016-06-21

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly's power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer's disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design.

  17. Exquisite light sensitivity of Drosophila melanogaster cryptochrome.

    PubMed

    Vinayak, Pooja; Coupar, Jamie; Hughes, S Emile; Fozdar, Preeya; Kilby, Jack; Garren, Emma; Yoshii, Taishi; Hirsh, Jay

    2013-01-01

    Drosophila melanogaster shows exquisite light sensitivity for modulation of circadian functions in vivo, yet the activities of the Drosophila circadian photopigment cryptochrome (CRY) have only been observed at high light levels. We studied intensity/duration parameters for light pulse induced circadian phase shifts under dim light conditions in vivo. Flies show far greater light sensitivity than previously appreciated, and show a surprising sensitivity increase with pulse duration, implying a process of photic integration active up to at least 6 hours. The CRY target timeless (TIM) shows dim light dependent degradation in circadian pacemaker neurons that parallels phase shift amplitude, indicating that integration occurs at this step, with the strongest effect in a single identified pacemaker neuron. Our findings indicate that CRY compensates for limited light sensitivity in vivo by photon integration over extraordinarily long times, and point to select circadian pacemaker neurons as having important roles.

  18. The genome sequence of Drosophila melanogaster.

    SciTech Connect

    2000-03-24

    The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the {approximately}120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes {approximately}13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

  19. Progress Towards Drosophila Epithelial Cell Culture

    PubMed Central

    Simcox, Amanda

    2015-01-01

    Drosophila epithelial research is at the forefront of the field; however, there are no well-characterized epithelial cell lines that could provide a complementary in vitro model for studies conducted in vivo. Here, a protocol is described that produces epithelial cell lines. The method uses genetic manipulation of oncogenes or tumor suppressors to induce embryonic primary culture cells to rapidly progress to permanent cell lines. It is, however, a general method and the type of cells that comprise a given line is not controlled experimentally. Indeed, only a small fraction of the lines produced are epithelial in character. For this reason, additional work needs to be done to develop a more robust epithelial cell-specific protocol. It is expected that Drosophila epithelial cell lines will have great utility for in vitro analysis of epithelial biology, particularly high-throughput analyses such as RNAi screens. PMID:23097097

  20. Chitosan nanofiber production from Drosophila by electrospinning.

    PubMed

    Kaya, Murat; Akyuz, Bahar; Bulut, Esra; Sargin, Idris; Eroglu, Fatma; Tan, Gamze

    2016-11-01

    Drosophila melanogaster is one of the important test organisms in genetics thanks to its fast growth rate in a culture. This study demonstrates that the fly D. melanogaster can also be exploited as a source for nanofiber production in biotechnical applications. First, its chitin content was determined (7.85%) and then high molecular weight chitosan (141.4kDa) was synthesized through deacetylation of chitin isolates. Chitosan nanofibers with the diameter of 40.0073±12.347nm were produced by electrospinning of Drosophila chitosan. The physicochemical properties of obtained chitin and chitosan from D. melanogaster were determined by Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). The study demonstrated that the fly D. melanogaster can be utilized for production of chitosan nanofiber concerning its cultivability and low-cost culture requirements.

  1. Predatory cannibalism in Drosophila melanogaster larvae.

    PubMed

    Vijendravarma, Roshan K; Narasimha, Sunitha; Kawecki, Tadeusz J

    2013-01-01

    Hunting live prey is risky and thought to require specialized adaptations. Therefore, observations of predatory cannibalism in otherwise non-carnivorous animals raise questions about its function, adaptive significance and evolutionary potential. Here we document predatory cannibalism on larger conspecifics in Drosophila melanogaster larvae and address its evolutionary significance. We found that under crowded laboratory conditions younger larvae regularly attack and consume 'wandering-stage' conspecifics, forming aggregations mediated by chemical cues from the attacked victim. Nutrition gained this way can be significant: an exclusively cannibalistic diet was sufficient for normal development from eggs to fertile adults. Cannibalistic diet also induced plasticity of larval mouth parts. Finally, during 118 generations of experimental evolution, replicated populations maintained under larval malnutrition evolved enhanced propensity towards cannibalism. These results suggest that, at least under laboratory conditions, predation on conspecifics in Drosophila is a functional, adaptive behaviour, which can rapidly evolve in response to nutritional conditions.

  2. Heat shock proteins and Drosophila aging.

    PubMed

    Tower, John

    2011-05-01

    Since their discovery in Drosophila, the heat shock proteins (Hsps) have been shown to regulate both stress resistance and life-span. Aging is characterized by increased oxidative stress and the accumulation of abnormal (malfolded) proteins, and these stresses induce Hsp gene expression through the transcription factor HSF. In addition, a subset of Hsps is induced by oxidative stress through the JNK signaling pathway and the transcription factor Foxo. The Hsps counteract the toxicity of abnormal proteins by facilitating protein refolding and turnover, and through other mechanisms including inhibition of apoptosis. The Hsps are up-regulated in tissue-specific patterns during aging, and their expression correlates with, and sometimes predicts, life span, making them ideal biomarkers of aging. The tools available for experimentally manipulating gene function and assaying healthspan in Drosophila provides an unparalleled opportunity to further study the role of Hsps in aging.

  3. Overview of Drosophila immunity: a historical perspective.

    PubMed

    Imler, Jean-Luc

    2014-01-01

    The functional analysis of genes from the model organism Drosophila melanogaster has provided invaluable information for many cellular and developmental or physiological processes, including immunity. The best-understood aspect of Drosophila immunity is the inducible humoral response, first recognized in 1972. This pioneering work led to a remarkable series of findings over the next 30 years, ranging from the identification and characterization of the antimicrobial peptides produced, to the deciphering of the signalling pathways activating the genes that encode them and, ultimately, to the discovery of the receptors sensing infection. These studies on an insect model coincided with a revival of the field of innate immunity, and had an unanticipated impact on the biomedical field.

  4. Motor neurons controlling fluid ingestion in Drosophila.

    PubMed

    Manzo, Andrea; Silies, Marion; Gohl, Daryl M; Scott, Kristin

    2012-04-17

    Rhythmic motor behaviors such as feeding are driven by neural networks that can be modulated by external stimuli and internal states. In Drosophila, ingestion is accomplished by a pump that draws fluid into the esophagus. Here we examine how pumping is regulated and characterize motor neurons innervating the pump. Frequency of pumping is not affected by sucrose concentration or hunger but is altered by fluid viscosity. Inactivating motor neurons disrupts pumping and ingestion, whereas activating them elicits arrhythmic pumping. These motor neurons respond to taste stimuli and show prolonged activity to palatable substances. This work describes an important component of the neural circuit for feeding in Drosophila and is a step toward understanding the rhythmic activity producing ingestion.

  5. Flightless Flies: Drosophila models of neuromuscular disease

    PubMed Central

    Lloyd, Thomas E.; Taylor, J. Paul

    2010-01-01

    The fruit fly, Drosophila melanogaster, has a long and rich history as an important model organism for biologists. In particular, study of the fruit fly has been essential to much of our fundamental understanding of the development and function of the nervous system. In recent years, studies using fruit flies have provided important insights into the pathogenesis of neurodegenerative and neuromuscular diseases. Fly models of spinal muscular atrophy, spinobulbar muscular atrophy, myotonic dystrophy, dystrophinopathies and other inherited neuromuscular diseases recapitulate many of the key pathologic features of the human disease. The ability to perform genetic screens holds promise for uncovering the molecular mechanisms of disease, and indeed, for identifying novel therapeutic targets. This review will summarize recent progress in developing fly models of neuromuscular diseases and will emphasize the contribution that Drosophila has made to our understanding of these diseases. PMID:20329357

  6. Quantifying and predicting Drosophila larvae crawling phenotypes

    NASA Astrophysics Data System (ADS)

    Günther, Maximilian N.; Nettesheim, Guilherme; Shubeita, George T.

    2016-06-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design.

  7. The secret lives of Drosophila flies

    PubMed Central

    Markow, Therese Ann

    2015-01-01

    Abstract Flies of the genus Drosophila, and particularly those of the species Drosophila melanogaster, are best known as laboratory organisms. As with all model organisms, they were domesticated for empirical studies, but they also continue to exist as wild populations. Decades of research on these flies in the laboratory have produced astounding and important insights into basic biological processes, but we have only scratched the surface of what they have to offer as research organisms. An outstanding challenge now is to build on this knowledge and explore how natural history has shaped D. melanogaster in order to advance our understanding of biology more generally. DOI: http://dx.doi.org/10.7554/eLife.06793.001 PMID:26041333

  8. Localization and characterization of X chromosome inversion breakpoints separating Drosophila mojavensis and Drosophila arizonae.

    PubMed

    Cirulli, Elizabeth T; Noor, Mohamed A F

    2007-01-01

    Ectopic exchange between transposable elements or other repetitive sequences along a chromosome can produce chromosomal inversions. As a result, genome sequence studies typically find sequence similarity between corresponding inversion breakpoint regions. Here, we identify and investigate the breakpoint regions of the X chromosome inversion distinguishing Drosophila mojavensis and Drosophila arizonae. We localize one inversion breakpoint to 13.7 kb and localize the other to a 1-Mb interval. Using this localization and assuming microsynteny between Drosophila melanogaster and D. arizonae, we pinpoint likely positions of the inversion breakpoints to windows of less than 3000 bp. These breakpoints define the size of the inversion to approximately 11 Mb. However, in contrast to many other studies, we fail to find significant sequence similarity between the 2 breakpoint regions. The localization of these inversion breakpoints will facilitate future genetic and molecular evolutionary studies in this species group, an emerging model system for ecological genetics.

  9. Queuine metabolism and cadmium toxicity in Drosophila

    SciTech Connect

    Farkas, W.R.; Siard, T. ); Jacobson, K.B. )

    1991-03-11

    Queuine is a derivative of guanine found in the first position of the anticodon of the transfer RNAs for Asp, Asn, His and Tyr. The transcripts of these tRNAs contain a guanine in this position. This guanine is enzymatically excised and replaced by queuine. The ratio of queuine-containing or (q+) tRNA to its precursor or (q{minus}) tRNA changes throughout the Drosophila life cycle. in the egg 10% of the tRNA is (q+). During the three larval stages this ratio drops to zero. In the one day old adult it is about 10%. It has previously been shown that when flies are selected for the ability to grow in the presence of cadmium, the tolerant flies had 100% (q+) tRNA at the first day after pupation instead of 10%. However, it was not known whether the elevated level of (q+) tRNA was a coincidence or if the elevated levels of (q+) tRNA was protective. The authors explored this problem using germfree Drosophila. The first thing was to determine if Drosophila can synthesize queuine. Sterilized eggs were seeded onto sterile chemically defined medium. The flies were grown to the adult stage. This study showed that Drosophila like mammals cannot synthesize queuine. A second result of this research was the demonstration that the authors could alter the ratio of (q+) to (q{minus}) tRNA by adding exogenous queuine to the medium e.g. at 0.008 mM queuine the (q+) tRNA was 95% instead of {lt} 5% in the last instar stage. Finally, the authors investigated whether or not queuine gave protection against cadmium. The results were that when the flies were grown in the presence of 0.2 mM cadmium queuine at 0.008 mM gave a statistically significant increase in the number of survivors.

  10. Dimethylnitrosamine demethylase activity in Drosophila melanogaster

    SciTech Connect

    Waters, L.C.; Nix, C.E.; Epler, J.L.

    1982-06-15

    A dimethylnitrosamine (DMN) demethylase with levels of activity comparable to that in uninduced rat liver was demonstrated in both larval and adult forms of the Hikone-R strain of Drosophila. A microsomal enzyme, it has many properties of a cytochrome P-450-containing mixed-function oxidase. Kinetic analysis indicates only a single enzyme with an apparent K/sub m/ of 10.5 mM DMN.

  11. Visual learning in individually assayed Drosophila larvae.

    PubMed

    Gerber, B; Scherer, S; Neuser, K; Michels, B; Hendel, T; Stocker, R F; Heisenberg, M

    2004-01-01

    An understanding of associative learning is facilitated if it can be analyzed in a simple animal like the fruit fly Drosophila. Here, we introduce the first visual associative learning paradigm for larval Drosophila; this is remarkable as larvae have an order of magnitude fewer neurons than adult flies. Larvae were subjected to either of two reciprocal training regimes: Light+/Dark- or Light-/Dark+. Subsequently, all larvae were individually tested for their preference between Light versus Dark. The difference between training regimes was therefore exclusively which visual situation was associated with which reinforcer; differences observed during the test thus reflected exclusively associative learning. For positive reinforcement (+) we used fructose (FRU), and for negative reinforcement (-) either quinine or sodium chloride (QUI, NaCl). Under these conditions, associative learning could be reproducibly observed in both wild-type strains tested. We then compared the effectiveness of training using differential conditioning, with both positive and negative reinforcement, to that using only positive or only negative reinforcement. We found that FRU only, but neither QUI nor NaCl, was in itself effective as a reinforcer. This is the first demonstration of appetitive learning in larval Drosophila. It is now possible to investigate the behavioral and neuronal organization of appetitive visual learning in this simple and genetically easy-to-manipulate experimental system.

  12. Flying Drosophila Orient to Sky Polarization

    PubMed Central

    Weir, Peter T.; Dickinson, Michael H.

    2015-01-01

    Summary Insects maintain a constant bearing across a wide range of spatial scales. Monarch butterflies and locusts traverse continents [1, 2], foraging bees and ants travel hundreds of meters to return to their nest [1, 3, 4], whereas many other insects fly straight for only a few centimeters before changing direction. Despite this variation in spatial scale, the brain region thought to underlie long-distance navigation is remarkably conserved [5, 6], suggesting that the use of celestial cues for navigation is a general and perhaps ancient behavioral capability of insects. Laboratory studies of Drosophila have identified a local search mode in which short straight segments are interspersed with rapid turns [7, 8]. Such flight modes, however, are inconsistent with measures of gene flow between geographically-separated populations [9-11], and individual Drosophila have been observed to travel 10 km across desert terrain in a single night [9, 12, 13] – a feat that would be impossible without prolonged periods of straight flight. To directly examine orientation behavior under outdoor conditions, we built a portable flight arena in which a fly viewed the natural sky through a liquid crystal device that could experimentally rotate the angle of polarization. Our findings indicate that flying Drosophila actively orient using the sky's natural polarization pattern. PMID:22177905

  13. dachshund Potentiates Hedgehog Signaling during Drosophila Retinogenesis

    PubMed Central

    Aerts, Stein; Casares, Fernando; Janody, Florence

    2016-01-01

    Proper organ patterning depends on a tight coordination between cell proliferation and differentiation. The patterning of Drosophila retina occurs both very fast and with high precision. This process is driven by the dynamic changes in signaling activity of the conserved Hedgehog (Hh) pathway, which coordinates cell fate determination, cell cycle and tissue morphogenesis. Here we show that during Drosophila retinogenesis, the retinal determination gene dachshund (dac) is not only a target of the Hh signaling pathway, but is also a modulator of its activity. Using developmental genetics techniques, we demonstrate that dac enhances Hh signaling by promoting the accumulation of the Gli transcription factor Cubitus interruptus (Ci) parallel to or downstream of fused. In the absence of dac, all Hh-mediated events associated to the morphogenetic furrow are delayed. One of the consequences is that, posterior to the furrow, dac- cells cannot activate a Roadkill-Cullin3 negative feedback loop that attenuates Hh signaling and which is necessary for retinal cells to continue normal differentiation. Therefore, dac is part of an essential positive feedback loop in the Hh pathway, guaranteeing the speed and the accuracy of Drosophila retinogenesis. PMID:27442438

  14. The Ran Pathway in Drosophila melanogaster Mitosis

    PubMed Central

    Chen, Jack W. C.; Barker, Amy R.; Wakefield, James G.

    2015-01-01

    Over the last two decades, the small GTPase Ran has emerged as a central regulator of both mitosis and meiosis, particularly in the generation, maintenance, and regulation of the microtubule (MT)-based bipolar spindle. Ran-regulated pathways in mitosis bear many similarities to the well-characterized functions of Ran in nuclear transport and, as with transport, the majority of these mitotic effects are mediated through affecting the physical interaction between karyopherins and Spindle Assembly Factors (SAFs)—a loose term describing proteins or protein complexes involved in spindle assembly through promoting nucleation, stabilization, and/or depolymerization of MTs, through anchoring MTs to specific structures such as centrosomes, chromatin or kinetochores, or through sliding MTs along each other to generate the force required to achieve bipolarity. As such, the Ran-mediated pathway represents a crucial functional module within the wider spindle assembly landscape. Research into mitosis using the model organism Drosophila melanogaster has contributed substantially to our understanding of centrosome and spindle function. However, in comparison to mammalian systems, very little is known about the contribution of Ran-mediated pathways in Drosophila mitosis. This article sets out to summarize our understanding of the roles of the Ran pathway components in Drosophila mitosis, focusing on the syncytial blastoderm embryo, arguing that it can provide important insights into the conserved functions on Ran during spindle formation. PMID:26636083

  15. Olfactory Learning in Individually Assayed Drosophila Larvae

    PubMed Central

    Scherer, Sabine; Stocker, Reinhard F.; Gerber, Bertram

    2003-01-01

    Insect and mammalian olfactory systems are strikingly similar. Therefore, Drosophila can be used as a simple model for olfaction and olfactory learning. The brain of adult Drosophila, however, is still complex. We therefore chose to work on the larva with its yet simpler but adult-like olfactory system and provide evidence for olfactory learning in individually assayed Drosophila larvae. We developed a differential conditioning paradigm in which odorants are paired with positive (“+” fructose) or negative (“-” quinine or sodium chloride) gustatory reinforcers. Test performance of individuals from two treatment conditions is compared—one received odorant A with the positive reinforcer and odorant B with a negative reinforcer (A+/B-); animals from the other treatment condition were trained reciprocally (A-/B+). During test, differences in choice between A and B of individuals having undergone either A+/B- or A-/B+ training therefore indicate associative learning. We provide such evidence for both combinations of reinforcers; this was replicable across repetitions, laboratories, and experimenters. We further show that breaks improve performance, in accord with basic principles of associative learning. The present individual assay will facilitate electrophysiological studies, which necessarily use individuals. As such approaches are established for the larval neuromuscular synapse, but not in adults, an individual larval learning paradigm will serve to link behavioral levels of analysis to synaptic physiology. PMID:12773586

  16. Odor and pheromone detection in Drosophila melanogaster.

    PubMed

    Smith, Dean P

    2007-08-01

    Drosophila melanogaster has proven to be a useful model system to probe the mechanisms underlying the detection, discrimination, and perception of volatile odorants. The relatively small receptor repertoire of 62 odorant receptors makes the goal of understanding odor responses from the total receptor repertoire approachable in this system, and recent work has been directed toward this goal. In addition, new work not only sheds light but also raises more questions about the initial steps in odor perception in this system. Odorant receptor genes in Drosophila are predicted to encode seven transmembrane receptors, but surprising data suggest that these receptors may be inverted in the plasma membrane compared to classical G-protein coupled receptors. Finally, although some Drosophila odorant receptors are activated directly by odorant molecules, detection of a volatile pheromone, 11-cis vaccenyl acetate requires an extracellular adapter protein called LUSH for activation of pheromone sensitive neurons. Because pheromones are used by insects to trigger mating and other behaviors, these insights may herald new approaches to control behavior in pathogenic and agricultural pest insects.

  17. Homolog pairing and segregation in Drosophila meiosis.

    PubMed

    McKee, B D

    2009-01-01

    Pairing of homologous chromosomes is fundamental to their reliable segregation during meiosis I and thus underlies sexual reproduction. In most eukaryotes homolog pairing is confined to prophase of meiosis I and is accompanied by frequent exchanges, known as crossovers, between homologous chromatids. Crossovers give rise to chiasmata, stable interhomolog connectors that are required for bipolar orientation (orientation to opposite poles) of homologs during meiosis I. Drosophila is unique among model eukaryotes in exhibiting regular homolog pairing in mitotic as well as meiotic cells. I review the results of recent molecular studies of pairing in both mitosis and meiosis in Drosophila. These studies show that homolog pairing is continuous between pre-meiotic mitosis and meiosis but that pairing frequencies and patterns are altered during the mitotic-meiotic transition. They also show that, with the exception of X-Y pairing in male meiosis, which is mediated specifically by the 240-bp rDNA spacer repeats, chromosome pairing is not restricted to specific sites in either mitosis or meiosis. Instead, virtually all chromosome regions, both heterochromatic and euchromatic, exhibit autonomous pairing capacity. Mutations that reduce the frequencies of both mitotic and meiotic pairing have been recently described, but no mutations that abolish pairing completely have been discovered, and the genetic control of pairing in Drosophila remains to be elucidated.

  18. Flying Drosophila orient to sky polarization.

    PubMed

    Weir, Peter T; Dickinson, Michael H

    2012-01-10

    Insects maintain a constant bearing across a wide range of spatial scales. Monarch butterflies and locusts traverse continents [1, 2], and foraging bees and ants travel hundreds of meters to return to their nests [1, 3, 4], whereas many other insects fly straight for only a few centimeters before changing direction. Despite this variation in spatial scale, the brain region thought to underlie long-distance navigation is remarkably conserved [5, 6], suggesting that the use of a celestial compass is a general and perhaps ancient capability of insects. Laboratory studies of Drosophila have identified a local search mode in which short, straight segments are interspersed with rapid turns [7, 8]. However, this flight mode is inconsistent with measured gene flow between geographically separated populations [9-11], and individual Drosophila can travel 10 km across desert terrain in a single night [9, 12, 13]-a feat that would be impossible without prolonged periods of straight flight. To directly examine orientation behavior under outdoor conditions, we built a portable flight arena in which a fly viewed the natural sky through a liquid crystal device that could experimentally rotate the polarization angle. Our findings indicate that Drosophila actively orient using the sky's natural polarization pattern.

  19. ‘Peer pressure’ in larval Drosophila?

    PubMed Central

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

    2014-01-01

    ABSTRACT Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on ‘peer pressure’, that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila. PMID:24907371

  20. SPARC–Dependent Cardiomyopathy in Drosophila

    PubMed Central

    Motamedchaboki, Khatereh; Bodmer, Rolf

    2016-01-01

    Background— The Drosophila heart is an important model for studying the genetics underpinning mammalian cardiac function. The system comprises contractile cardiomyocytes, adjacent to which are pairs of highly endocytic pericardial nephrocytes that modulate cardiac function by uncharacterized mechanisms. Identifying these mechanisms and the molecules involved is important because they may be relevant to human cardiac physiology. Methods and Results— This work aimed to identify circulating cardiomodulatory factors of potential relevance to humans using the Drosophila nephrocyte–cardiomyocyte system. A Kruppel-like factor 15 (dKlf15) loss-of-function strategy was used to ablate nephrocytes and then heart function and the hemolymph proteome were analyzed. Ablation of nephrocytes led to a severe cardiomyopathy characterized by a lengthening of diastolic interval. Rendering adult nephrocytes dysfunctional by disrupting their endocytic function or temporally conditional knockdown of dKlf15 led to a similar cardiomyopathy. Proteomics revealed that nephrocytes regulate the circulating levels of many secreted proteins, the most notable of which was the evolutionarily conserved matricellular protein Secreted Protein Acidic and Rich in Cysteine (SPARC), a protein involved in mammalian cardiac function. Finally, reducing SPARC gene dosage ameliorated the cardiomyopathy that developed in the absence of nephrocytes. Conclusions— The data implicate SPARC in the noncell autonomous control of cardiac function in Drosophila and suggest that modulation of SPARC gene expression may ameliorate cardiac dysfunction in humans. PMID:26839388

  1. Neurophysiology of Drosophila Models of Parkinson's Disease

    PubMed Central

    West, Ryan J. H.; Furmston, Rebecca; Williams, Charles A. C.; Elliott, Christopher J. H.

    2015-01-01

    We provide an insight into the role Drosophila has played in elucidating neurophysiological perturbations associated with Parkinson's disease- (PD-) related genes. Synaptic signalling deficits are observed in motor, central, and sensory systems. Given the neurological impact of disease causing mutations within these same genes in humans the phenotypes observed in fly are of significant interest. As such we observe four unique opportunities provided by fly nervous system models of Parkinson's disease. Firstly, Drosophila models are instrumental in exploring the mechanisms of neurodegeneration, with several PD-related mutations eliciting related phenotypes including sensitivity to energy supply and vesicular deformities. These are leading to the identification of plausible cellular mechanisms, which may be specific to (dopaminergic) neurons and synapses rather than general cellular phenotypes. Secondly, models show noncell autonomous signalling within the nervous system, offering the opportunity to develop our understanding of the way pathogenic signalling propagates, resembling Braak's scheme of spreading pathology in PD. Thirdly, the models link physiological deficits to changes in synaptic structure. While the structure-function relationship is complex, the genetic tractability of Drosophila offers the chance to separate fundamental changes from downstream consequences. Finally, the strong neuronal phenotypes permit relevant first in vivo drug testing. PMID:25960916

  2. Juvenile hormone regulation of Drosophila aging

    PubMed Central

    2013-01-01

    Background Juvenile hormone (JH) has been demonstrated to control adult lifespan in a number of non-model insects where surgical removal of the corpora allata eliminates the hormone’s source. In contrast, little is known about how juvenile hormone affects adult Drosophila melanogaster. Previous work suggests that insulin signaling may modulate Drosophila aging in part through its impact on juvenile hormone titer, but no data yet address whether reduction of juvenile hormone is sufficient to control Drosophila life span. Here we adapt a genetic approach to knock out the corpora allata in adult Drosophila melanogaster and characterize adult life history phenotypes produced by reduction of juvenile hormone. With this system we test potential explanations for how juvenile hormone modulates aging. Results A tissue specific driver inducing an inhibitor of a protein phosphatase was used to ablate the corpora allata while permitting normal development of adult flies. Corpora allata knockout adults had greatly reduced fecundity, inhibited oogenesis, impaired adult fat body development and extended lifespan. Treating these adults with the juvenile hormone analog methoprene restored all traits toward wildtype. Knockout females remained relatively long-lived even when crossed into a genotype that blocked all egg production. Dietary restriction further extended the lifespan of knockout females. In an analysis of expression profiles of knockout females in fertile and sterile backgrounds, about 100 genes changed in response to loss of juvenile hormone independent of reproductive state. Conclusions Reduced juvenile hormone alone is sufficient to extend the lifespan of Drosophila melanogaster. Reduced juvenile hormone limits reproduction by inhibiting the production of yolked eggs, and this may arise because juvenile hormone is required for the post-eclosion development of the vitellogenin-producing adult fat body. Our data do not support a mechanism for juvenile hormone control

  3. Susceptibility of cranberries to Drosophila suzukii (Diptera: Drosophilidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii Mastsumura (Diptera: Drosophilidae), commonly referred to as the spotted-wing drosophila, is an exotic species that has proven a troublesome pest of fruit production in the U.S. The fly targets small fruit and thus represents a concern for the U.S. cranberry industry. Two studies ...

  4. Cranberries and Spotted Wing Drosophila (SWD) in Wisconsin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii, commonly known as spotted wing drosophila (SWD), does not appear to like cranberries very much. Following multiple replicated trials using ripe, under-ripe, and over-ripe organic Wisconsin cranberries, SWD females would not (or could not) insert eggs into under-ripe or ripe cranb...

  5. Spotted wing drosophila: a new invasive pest of Mississippi berries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted Wing Drosophila (SWD) Drosophila suzukii, a native fly of Southeast Asia, is a widely reported and highly invasive pest of fruit crops in North America and Mediterranean Europe. Between 2010 and 2011, SWD was confirmed in most States in eastern North America. During this same period, SWD was...

  6. First foreign exploration for asian parasitoids of Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The invasive spotted wing drosophila, Drosophila suzukii Matsumura (Dipt.: Drosophilidae), is a native of East Asia and is now widely established in North America and Europe, where it is a serious pest of small and stone fruit crops. The lack of effective indigenous parasitoids of D. suzukii in the ...

  7. Gene Networks Underlying Chronic Sleep Deprivation in Drosophila

    DTIC Science & Technology

    2014-06-15

    SECURITY CLASSIFICATION OF: Studies of the gene network affected by sleep deprivation and stress in the fruit fly Drosophila have revealed the...transduction pathways are affected. Subseuqent tests of mutants in these pathways demonstrated a strong effect on sleep maintenance. Further...15-Apr-2009 14-Apr-2013 Approved for Public Release; Distribution Unlimited Gene Networks Underlying Chronic Sleep Deprivation in Drosophila The

  8. Drosophila lacks C20 and C22 polyunsaturated fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila melanogaster has been considered an ideal model organism to investigate human diseases and genetic pathways. Whether Drosophila is an ideal model for nutrigenomics, especially for fatty acid metabolism, however, remains to be illustrated. This study was to examine the metabolism of C20 an...

  9. Drosophila suzukii population response to environment and management strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted wing drosophila, Drosophila suzukii, quickly emerged as a devastating invasive pest of small and stone fruits in the Americas and Europe. To better understand the population dynamics of D. suzukii, we reviewed recent work on juvenile development, adult reproduction, and seasonal variation in...

  10. The developmental transcriptome of Drosophila melanogaster

    SciTech Connect

    University of Connecticut; Graveley, Brenton R.; Brooks, Angela N.; Carlson, Joseph W.; Duff, Michael O.; Landolin, Jane M.; Yang, Li; Artieri, Carlo G.; van Baren, Marijke J.; Boley, Nathan; Booth, Benjamin W.; Brown, James B.; Cherbas, Lucy; Davis, Carrie A.; Dobin, Alex; Li, Renhua; Lin, Wei; Malone, John H.; Mattiuzzo, Nicolas R.; Miller, David; Sturgill, David; Tuch, Brian B.; Zaleski, Chris; Zhang, Dayu; Blanchette, Marco; Dudoit, Sandrine; Eads, Brian; Green, Richard E.; Hammonds, Ann; Jiang, Lichun; Kapranov, Phil; Langton, Laura; Perrimon, Norbert; Sandler, Jeremy E.; Wan, Kenneth H.; Willingham, Aarron; Zhang, Yu; Zou, Yi; Andrews, Justen; Bicke, Peter J.; Brenner, Steven E.; Brent, Michael R.; Cherbas, Peter; Gingeras, Thomas R.; Hoskins, Roger A.; Kaufman, Thomas C.; Oliver, Brian; Celniker, Susan E.

    2010-12-02

    Drosophila melanogaster is one of the most well studied genetic model organisms; nonetheless, its genome still contains unannotated coding and non-coding genes, transcripts, exons and RNA editing sites. Full discovery and annotation are pre-requisites for understanding how the regulation of transcription, splicing and RNA editing directs the development of this complex organism. Here we used RNA-Seq, tiling microarrays and cDNA sequencing to explore the transcriptome in 30 distinct developmental stages. We identified 111,195 new elements, including thousands of genes, coding and non-coding transcripts, exons, splicing and editing events, and inferred protein isoforms that previously eluded discovery using established experimental, prediction and conservation-based approaches. These data substantially expand the number of known transcribed elements in the Drosophila genome and provide a high-resolution view of transcriptome dynamics throughout development. Drosophila melanogaster is an important non-mammalian model system that has had a critical role in basic biological discoveries, such as identifying chromosomes as the carriers of genetic information and uncovering the role of genes in development. Because it shares a substantial genic content with humans, Drosophila is increasingly used as a translational model for human development, homeostasis and disease. High-quality maps are needed for all functional genomic elements. Previous studies demonstrated that a rich collection of genes is deployed during the life cycle of the fly. Although expression profiling using microarrays has revealed the expression of, 13,000 annotated genes, it is difficult to map splice junctions and individual base modifications generated by RNA editing using such approaches. Single-base resolution is essential to define precisely the elements that comprise the Drosophila transcriptome. Estimates of the number of transcript isoforms are less accurate than estimates of the number of genes

  11. Rhodopsin 7–The unusual Rhodopsin in Drosophila

    PubMed Central

    2016-01-01

    Rhodopsins are the major photopigments in the fruit fly Drosophila melanogaster. Drosophila express six well-characterized Rhodopsins (Rh1–Rh6) with distinct absorption maxima and expression pattern. In 2000, when the Drosophila genome was published, a novel Rhodopsin gene was discovered: Rhodopsin 7 (Rh7). Rh7 is highly conserved among the Drosophila genus and is also found in other arthropods. Phylogenetic trees based on protein sequences suggest that the seven Drosophila Rhodopsins cluster in three different groups. While Rh1, Rh2 and Rh6 form a “vertebrate-melanopsin-type”–cluster, and Rh3, Rh4 and Rh5 form an “insect-type”-Rhodopsin cluster, Rh7 seem to form its own cluster. Although Rh7 has nearly all important features of a functional Rhodopsin, it differs from other Rhodopsins in its genomic and structural properties, suggesting it might have an overall different role than other known Rhodopsins. PMID:27651995

  12. Drosophila melanogaster as a model organism to study nanotoxicity.

    PubMed

    Ong, Cynthia; Yung, Lin-Yue Lanry; Cai, Yu; Bay, Boon-Huat; Baeg, Gyeong-Hun

    2015-05-01

    Drosophila melanogaster has been used as an in vivo model organism for the study of genetics and development since 100 years ago. Recently, the fruit fly Drosophila was also developed as an in vivo model organism for toxicology studies, in particular, the field of nanotoxicity. The incorporation of nanomaterials into consumer and biomedical products is a cause for concern as nanomaterials are often associated with toxicity in many in vitro studies. In vivo animal studies of the toxicity of nanomaterials with rodents and other mammals are, however, limited due to high operational cost and ethical objections. Hence, Drosophila, a genetically tractable organism with distinct developmental stages and short life cycle, serves as an ideal organism to study nanomaterial-mediated toxicity. This review discusses the basic biology of Drosophila, the toxicity of nanomaterials, as well as how the Drosophila model can be used to study the toxicity of various types of nanomaterials.

  13. Rapid and highly accurate detection of Drosophila suzukii, spotted wing Drosophila (Diptera: Drosophilidae) by loop-mediated isothermal amplification assays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii, the spotted wing drosophila (SWD), is currently a major pest that causes severe economic losses to thin-skinned, small fruit growers in North America and Europe. The monitoring and early detection of SWD in the field is of the utmost importance for its proper management. Althou...

  14. The influence of temperature and photoperiod on the reproductive diapause and cold tolerance of spotted-wing drosophila, Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge regarding the reproductive status of spotted-wing drosophila, Drosophila suzukii (Matsumura)(Diptera: Drosophilidae) is of critical importance in predicting potential infestations of this invasive pest, as eggs are laid in ripe or ripening fruit of several commercially important small frui...

  15. Optimizing postharvest methyl bromide treatments to control spotted wing drosophila, Drosophila suzukii, in sweet cherries from Western USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide (MB) chamber fumigations were evaluated for postharvest control of spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), in fresh sweet cherry exports from Western USA. Sweet cherries were infested with SWD, incubated to maximize numbers of the most M...

  16. New Drosophila P-like elements and reclassification of Drosophila P-elements subfamilies.

    PubMed

    Loreto, Elgion L S; Zambra, Francis M B; Ortiz, Mauro F; Robe, Lizandra J

    2012-07-01

    Genomic searches for P-like transposable elements were performed (1) in silico in the 12 available Drosophila genomes and (2) by PCR using degenerate primers in 21 Neotropical Drosophila species. In silico searches revealed P-like sequences only in Drosophila persimilis and Drosophila willistoni. Sixteen new P-like elements were obtained by PCR. These sequences were added to sequences of previously described P-like elements, and a phylogenetic analysis was performed. The subfamilies of P-elements described in the literature (Canonical, M, O, T, and K) were included in the reconstructed tree, and all were monophyletic. However, we suggest that some subfamilies can be enlarged, other subdivided, and some new subfamilies may be proposed, totalizing eleven subfamilies, most of which contain new P-like sequences. Our analyses support the monophyly of P-like elements in Drosophilidae. We suggest that, once these elements need host-specific factors to be mobilizable, the horizontal transfer (HT) of P-like elements may be inhibited among more distant taxa. Nevertheless, HT among Drosophilidae species appears to be a common phenomenon.

  17. Appetitive associative olfactory learning in Drosophila larvae.

    PubMed

    Apostolopoulou, Anthi A; Widmann, Annekathrin; Rohwedder, Astrid; Pfitzenmaier, Johanna E; Thum, Andreas S

    2013-02-18

    In the following we describe the methodological details of appetitive associative olfactory learning in Drosophila larvae. The setup, in combination with genetic interference, provides a handle to analyze the neuronal and molecular fundamentals of specifically associative learning in a simple larval brain. Organisms can use past experience to adjust present behavior. Such acquisition of behavioral potential can be defined as learning, and the physical bases of these potentials as memory traces. Neuroscientists try to understand how these processes are organized in terms of molecular and neuronal changes in the brain by using a variety of methods in model organisms ranging from insects to vertebrates. For such endeavors it is helpful to use model systems that are simple and experimentally accessible. The Drosophila larva has turned out to satisfy these demands based on the availability of robust behavioral assays, the existence of a variety of transgenic techniques and the elementary organization of the nervous system comprising only about 10,000 neurons (albeit with some concessions: cognitive limitations, few behavioral options, and richness of experience questionable). Drosophila larvae can form associations between odors and appetitive gustatory reinforcement like sugar. In a standard assay, established in the lab of B. Gerber, animals receive a two-odor reciprocal training: A first group of larvae is exposed to an odor A together with a gustatory reinforcer (sugar reward) and is subsequently exposed to an odor B without reinforcement. Meanwhile a second group of larvae receives reciprocal training while experiencing odor A without reinforcement and subsequently being exposed to odor B with reinforcement (sugar reward). In the following both groups are tested for their preference between the two odors. Relatively higher preferences for the rewarded odor reflect associative learning--presented as a performance index (PI). The conclusion regarding the associative

  18. The Drosophila EKC/KEOPS complex

    PubMed Central

    Rojas-Benítez, Diego; Ibar, Consuelo; Glavic, Álvaro

    2013-01-01

    The TOR signaling pathway is crucial in the translation of nutritional inputs into the protein synthesis machinery regulation, allowing animal growth. We recently identified the Bud32 (yeast)/PRPK (human) ortholog in Drosophila, Prpk (p53-related protein kinase), and found that it is required for TOR kinase activity. Bud32/PRPK is an ancient and atypical kinase conserved in evolution from Archeae to humans, being essential for Archeae. It has been linked with p53 stabilization in human cell culture and its absence in yeast causes a slow-growth phenotype. This protein has been associated to KEOPS (kinase, putative endopeptidase and other proteins of small size) complex together with Kae1p (ATPase), Cgi-121 and Pcc1p. This complex has been implicated in telomere maintenance, transcriptional regulation, bud site selection and chemical modification of tRNAs (tRNAs). Bud32p and Kae1p have been related with N6-threonylcarbamoyladenosine (t6A) synthesis, a particular chemical modification that occurs at position 37 of tRNAs that pair A-starting codons, required for proper translation in most species. Lack of this modification causes mistranslations and open reading frame shifts in yeast. The core constituents of the KEOPS complex are present in Drosophila, but their physical interaction has not been reported yet. Here, we present a review of the findings regarding the function of this complex in different organisms and new evidence that extends our recent observations of Prpk function in animal growth showing that depletion of Kae1 or Prpk, in accordance with their role in translation in yeast, is able to induce the unfolded protein response (UPR) in Drosophila. We suggest that EKC/KEOPS complex could be integrating t6A-modified tRNA availability with translational rates, which are ultimately reflected in animal growth. PMID:23823807

  19. Pheromones mediating copulation and attraction in Drosophila

    PubMed Central

    Dweck, Hany K. M.; Ebrahim, Shimaa A. M.; Thoma, Michael; Mohamed, Ahmed A. M.; Keesey, Ian W.; Trona, Federica; Lavista-Llanos, Sofia; Svatoš, Aleš; Sachse, Silke; Knaden, Markus; Hansson, Bill S.

    2015-01-01

    Intraspecific olfactory signals known as pheromones play important roles in insect mating systems. In the model Drosophila melanogaster, a key part of the pheromone-detecting system has remained enigmatic through many years of research in terms of both its behavioral significance and its activating ligands. Here we show that Or47b-and Or88a-expressing olfactory sensory neurons (OSNs) detect the fly-produced odorants methyl laurate (ML), methyl myristate, and methyl palmitate. Fruitless (fruM)-positive Or47b-expressing OSNs detect ML exclusively, and Or47b- and Or47b-expressing OSNs are required for optimal male copulation behavior. In addition, activation of Or47b-expressing OSNs in the male is sufficient to provide a competitive mating advantage. We further find that the vigorous male courtship displayed toward oenocyte-less flies is attributed to an oenocyte-independent sustained production of the Or47b ligand, ML. In addition, we reveal that Or88a-expressing OSNs respond to all three compounds, and that these neurons are necessary and sufficient for attraction behavior in both males and females. Beyond the OSN level, information regarding the three fly odorants is transferred from the antennal lobe to higher brain centers in two dedicated neural lines. Finally, we find that both Or47b- and Or88a-based systems and their ligands are remarkably conserved over a number of drosophilid species. Taken together, our results close a significant gap in the understanding of the olfactory background to Drosophila mating and attraction behavior; while reproductive isolation barriers between species are created mainly by species-specific signals, the mating enhancing signal in several Drosophila species is conserved. PMID:25964351

  20. Sialyltransferase regulates nervous system function in Drosophila

    PubMed Central

    Repnikova, Elena; Koles, Kate; Nakamura, Michiko; Pitts, Jared; Li, Haiwen; Ambavane, Apoorva; Zoran, Mark J.; Panin, Vladislav M.

    2012-01-01

    In vertebrates, sialylated glycans participate in a wide range of biological processes and affect nervous system’s development and function. 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, 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 behavioural, 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 α2,6 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. PMID:20445073

  1. The intimate genetics of Drosophila fertilization

    PubMed Central

    Loppin, Benjamin; Dubruille, Raphaëlle; Horard, Béatrice

    2015-01-01

    The union of haploid gametes at fertilization initiates the formation of the diploid zygote in sexually reproducing animals. This founding event of embryogenesis includes several fascinating cellular and nuclear processes, such as sperm–egg cellular interactions, sperm chromatin remodelling, centrosome formation or pronuclear migration. In comparison with other aspects of development, the exploration of animal fertilization at the functional level has remained so far relatively limited, even in classical model organisms. Here, we have reviewed our current knowledge of fertilization in Drosophila melanogaster, with a special emphasis on the genes involved in the complex transformation of the fertilizing sperm nucleus into a replicated set of paternal chromosomes. PMID:26246493

  2. Regulation of Drosophila lifespan by JNK signaling

    PubMed Central

    Biteau, Benoit; Karpac, Jason; Hwangbo, DaeSung; Jasper, Heinrich

    2010-01-01

    Cellular responses to extrinsic and intrinsic insults have to be carefully regulated to properly coordinate cytoprotection, repair processes, cell proliferation and apoptosis. Stress signaling pathways, most prominently the Jun-N-terminal Kinase (JNK) pathway, are critical regulators of such cellular responses and have accordingly been implicated in the regulation of lifespan in various organisms. JNK signaling promotes cytoprotective gene expression, but also interacts with the Insulin signaling pathway to influence growth, metabolism, stress tolerance and regeneration. Here, we review recent studies in Drosophila that elucidate the tissue-specific and systemic consequences of JNK activation that ultimately impact lifespan of the organism. PMID:21111799

  3. Somatic Instability of a Drosophila Chromosome

    PubMed Central

    Wines, D. R.; Henikoff, S.

    1992-01-01

    A mitotically unstable chromosome, detectable because of mosaic expression of marker genes, was generated by X-ray mutagenesis in Drosophila. Nondisjunction of this chromosome is evident in mitotic chromosome preparations, and premature sister chromatid separation is frequent. The mosaic phenotype is modified by genetic elements that are thought to alter chromatin structure. We hypothesize that the mitotic defects result from a breakpoint deep in the pericentric heterochromatin, within or very near to the DNA sequences essential for centromere function. This unique chromosome may provide a tool for the genetic and molecular dissection of a higher eukaryotic centromere. PMID:1628811

  4. Eye specification in Drosophila: perspectives and implications.

    PubMed

    Kumar, J P; Moses, K

    2001-12-01

    The discovery that Drosophila eyeless is homologous to vertebrate Pax6 produced enormous interest in eye specification and a reappraisal of eye evolution. While the transcription factor Eyeless/Pax6 is necessary and in some circumstances sufficient to induce eye development the simple story of eye specification has become more epic than haiku. At least seven other nuclear proteins act with Eyeless/Pax6 to induce the eye and, furthermore, extrinsic developmental signals are required. Some striking similarities between later events of retinal patterning in vertebrates and insects have led to a deeper debate on the evolutionary path to these apparently quite different organs.

  5. Hypergravity-induced altered behavior in Drosophila

    NASA Astrophysics Data System (ADS)

    Hosamani, Ravikumar; Wan, Judy; Marcu, Oana; Bhattacharya, Sharmila

    2012-07-01

    Microgravity and mechanical stress are important factors of the spaceflight environment, and affect astronaut health and behavior. Structural, functional, and behavioral mechanisms of all cells and organisms are adapted to Earth's gravitational force, 1G, while altered gravity can pose challenges to their adaptability to this new environment. On ground, hypergravity paradigms have been used to predict and complement studies on microgravity. Even small changes that take place at a molecular and genetic level during altered gravity may result in changes in phenotypic behavior. Drosophila provides a robust and simple, yet very reliable model system to understand the complexity of hypergravity-induced altered behavior, due to availability of a plethora of genetic tools. Locomotor behavior is a sensitive parameter that reflects the array of molecular adaptive mechanisms recruited during exposure to altered gravity. Thus, understanding the genetic basis of this behavior in a hypergravity environment could potentially extend our understanding of mechanisms of adaptation in microgravity. In our laboratory we are trying to dissect out the cellular and molecular mechanisms underlying hypergravity-induced oxidative stress, and its potential consequences on behavioral alterations by using Drosophila as a model system. In the present study, we employed pan-neuronal and mushroom body specific knock-down adult flies by using Gal4/UAS system to express inverted repeat transgenes (RNAi) to monitor and quantify the hypergravity-induced behavior in Drosophila. We established that acute hypergravity (3G for 60 min) causes a significant and robust decrease in the locomotor behavior in adult Drosophila, and that this change is dependent on genes related to Parkinson's disease, such as DJ-1α , DJ-1β , and parkin. In addition, we also showed that anatomically the control of this behavior is significantly processed in the mushroom body region of the fly brain. This work links a molecular

  6. Crystal structure of enolase from Drosophila melanogaster.

    PubMed

    Sun, Congcong; Xu, Baokui; Liu, Xueyan; Zhang, Zhen; Su, Zhongliang

    2017-04-01

    Enolase is an important enzyme in glycolysis and various biological processes. Its dysfunction is closely associated with diseases. Here, the enolase from Drosophila melanogaster (DmENO) was purified and crystallized. A crystal of DmENO diffracted to 2.0 Å resolution and belonged to space group R32. The structure was solved by molecular replacement. Like most enolases, DmENO forms a homodimer with conserved residues in the dimer interface. DmENO possesses an open conformation in this structure and contains conserved elements for catalytic activity. This work provides a structural basis for further functional and evolutionary studies of enolase.

  7. A connectionist model of the Drosophila blastoderm

    SciTech Connect

    Reinitz, J. . Dept. of Biological Sciences); Mjolsness, E. . Dept. of Computer Science); Sharp, D.H. . Theoretical Div.)

    1990-11-01

    The authors present a phenomenological modeling framework for development, and apply it to the network of segmentation genes operating in the blastoderm of Drosophila. Their purpose is to provide a systematic method for discovering and expressing correlations in experimental data on gene expression and other developmental processes. The modeling framework is based on a connectionist or neural net dynamics for biochemical regulators, coupled to grammatical rules which describe certain features of the birth, growth, and death of cells, synapses and other biological entities. They present preliminary numerical results regarding regulatory interactions between the genes Kruppel and knirps that demonstrate the potential utility of the model. 14 refs., 5 figs.

  8. Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

    SciTech Connect

    Knecht, Wolfgang; Mikkelsen, Nils Egil; Clausen, Anders Ranegaard; Willer, Mette; Gojkovic, Zoran

    2009-05-01

    Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) can additionally sensitize human cancer cell lines towards the anti-cancer drug gemcitabine. We show that this property is based on the Dm-dNK ability to efficiently phosphorylate gemcitabine. The 2.2 A resolution structure of Dm-dNK in complex with gemcitabine shows that the residues Tyr70 and Arg105 play a crucial role in the firm positioning of gemcitabine by extra interactions made by the fluoride atoms. This explains why gemcitabine is a good substrate for Dm-dNK.

  9. Determination of Blastoderm Cells in Drosophila melanogaster

    PubMed Central

    Chan, L.-N.; Gehring, W.

    1971-01-01

    A method for culturing blastoderm cells of Drosophila in vivo has been developed that allows these cells to differentiate into larval or adult structures. By intermixture of genetically marked cells from bisected and whole embryos, it was shown that blastoderm cells are restricted in their potential for forming adult epidermal structures. Cells isolated from anterior-half embryos are determined for forming head and thoracic structures, whereas cells from posterior-half embryos are determined for forming thoracic and abdominal structures. The specificity of determination and the localization of determinative factors is discussed. Images PMID:5002429

  10. Psychomotor Behavior: A Practical Approach in Drosophila

    PubMed Central

    Iliadi, Konstantin G.; Gluscencova, Oxana B.; Boulianne, Gabrielle L.

    2016-01-01

    Psychomotor behaviors are governed by fine relationships between physical activity and cognitive functions. Disturbances in psychomotor development and performance are a hallmark of many mental illnesses and often appear as observable and measurable behaviors. Here, we describe a new method called an “equilibrist test,” which can be used to quantify psychomotor learning and performance in Drosophila. We also show how this test can be used to quantify motor disturbances at relatively early stages in the development of neurodegenerative diseases. PMID:27630583

  11. Sensitivity and specificity in Drosophila pheromone perception.

    PubMed

    Benton, Richard

    2007-10-01

    How the brain perceives volatile chemicals in the environment to evoke the appropriate behaviour is a fundamental question in sensory neuroscience. The olfactory system of the fruit fly, Drosophila melanogaster, has emerged as a powerful model system to address this problem. Recent analysis of the molecular, neuroanatomical and physiological properties of the olfactory circuits that detect the sex and social aggregation pheromone cis-vaccenyl acetate now provides one of the most comprehensive outlines for the neural basis of odour perception. This review describes these latest advances, discusses what they reveal about where stimulus sensitivity and specificity is encoded in olfactory circuits, and considers future questions.

  12. Circadian Rhythms and Sleep in Drosophila melanogaster.

    PubMed

    Dubowy, Christine; Sehgal, Amita

    2017-04-01

    The advantages of the model organism Drosophila melanogaster, including low genetic redundancy, functional simplicity, and the ability to conduct large-scale genetic screens, have been essential for understanding the molecular nature of circadian (∼24 hr) rhythms, and continue to be valuable in discovering novel regulators of circadian rhythms and sleep. In this review, we discuss the current understanding of these interrelated biological processes in Drosophila and the wider implications of this research. Clock genes period and timeless were first discovered in large-scale Drosophila genetic screens developed in the 1970s. Feedback of period and timeless on their own transcription forms the core of the molecular clock, and accurately timed expression, localization, post-transcriptional modification, and function of these genes is thought to be critical for maintaining the circadian cycle. Regulators, including several phosphatases and kinases, act on different steps of this feedback loop to ensure strong and accurately timed rhythms. Approximately 150 neurons in the fly brain that contain the core components of the molecular clock act together to translate this intracellular cycling into rhythmic behavior. We discuss how different groups of clock neurons serve different functions in allowing clocks to entrain to environmental cues, driving behavioral outputs at different times of day, and allowing flexible behavioral responses in different environmental conditions. The neuropeptide PDF provides an important signal thought to synchronize clock neurons, although the details of how PDF accomplishes this function are still being explored. Secreted signals from clock neurons also influence rhythms in other tissues. SLEEP is, in part, regulated by the circadian clock, which ensures appropriate timing of sleep, but the amount and quality of sleep are also determined by other mechanisms that ensure a homeostatic balance between sleep and wake. Flies have been useful

  13. Research resources for Drosophila: the expanding universe.

    PubMed

    Matthews, Kathleen A; Kaufman, Thomas C; Gelbart, William M

    2005-03-01

    Drosophila melanogaster has been the subject of research into central questions about biological mechanisms for almost a century. The experimental tools and resources that are available or under development for D. melanogaster and its related species, particularly those for genomic analysis, are truly outstanding. Here we review three types of resource that have been developed for D. melanogaster research: databases and other sources of information, biological materials and experimental services. These resources are there to be exploited and we hope that this guide will encourage new uses for D. melanogaster information, materials and services, both by those new to flies and by experienced D. melanogaster researchers.

  14. Assessing senescence in Drosophila using video tracking.

    PubMed

    Ardekani, Reza; Tavaré, Simon; Tower, John

    2013-01-01

    Senescence is associated with changes in gene expression, including the upregulation of stress response- and innate immune response-related genes. In addition, aging animals exhibit characteristic changes in movement behaviors including decreased gait speed and a deterioration in sleep/wake rhythms. Here, we describe methods for tracking Drosophila melanogaster movements in 3D with simultaneous quantification of fluorescent transgenic reporters. This approach allows for the assessment of correlations between behavior, aging, and gene expression as well as for the quantification of biomarkers of aging.

  15. Biases in Drosophila melanogaster protein trap screens

    PubMed Central

    Aleksic, Jelena; Lazic, Ranko; Müller, Ilka; Russell, Steven R; Adryan, Boris

    2009-01-01

    Background The ability to localise or follow endogenous proteins in real time in vivo is of tremendous utility for cell biology or systems biology studies. Protein trap screens utilise the random genomic insertion of a transposon-borne artificial reporter exon (e.g. encoding the green fluorescent protein, GFP) into an intron of an endogenous gene to generate a fluorescent fusion protein. Despite recent efforts aimed at achieving comprehensive coverage of the genes encoded in the Drosophila genome, the repertoire of genes that yield protein traps is still small. Results We analysed the collection of available protein trap lines in Drosophila melanogaster and identified potential biases that are likely to restrict genome coverage in protein trap screens. The protein trap screens investigated here primarily used P-element vectors and thus exhibit some of the same positional biases associated with this transposon that are evident from the comprehensive Drosophila Gene Disruption Project. We further found that protein trap target genes usually exhibit broad and persistent expression during embryonic development, which is likely to facilitate better detection. In addition, we investigated the likely influence of the GFP exon on host protein structure and found that protein trap insertions have a significant bias for exon-exon boundaries that encode disordered protein regions. 38.8% of GFP insertions land in disordered protein regions compared with only 23.4% in the case of non-trapping P-element insertions landing in coding sequence introns (p < 10-4). Interestingly, even in cases where protein domains are predicted, protein trap insertions frequently occur in regions encoding surface exposed areas that are likely to be functionally neutral. Considering the various biases observed, we predict that less than one third of intron-containing genes are likely to be amenable to trapping by the existing methods. Conclusion Our analyses suggest that the utility of P

  16. Drosophila-associated yeast species in vineyard ecosystems.

    PubMed

    Lam, Samuel S T H; Howell, Kate S

    2015-10-01

    Yeast activity during wine fermentation directly contributes to wine quality, but the source and movement of yeasts in vineyards and winery environments have not been resolved. Here, we investigate the yeast species associated with the Drosophila insect vector to help understand yeast dispersal and persistence. Drosophila are commonly found in vineyards and are known to have a mutualistic relationship with yeasts in other ecosystems. Drosophilids were collected from vineyards, grape waste (marc) piles and wineries during grape harvest. Captured flies were identified morphologically, and their associated yeasts were identified. Drosophila melanogaster/D. simulans, D. hydei and Scaptodrosophila lativittata were identified in 296 captured Drosophila flies. These flies were associated with Metschnikowia pulcherrima, Hanseniaspora uvarum, Torulaspora delbrueckii and H. valbyensis yeasts. Yeast and Drosophila species diversity differed between collection locations (vineyard and marc: R = 0.588 for Drosophila and R = 0.644 for yeasts). Surprisingly, the primary wine fermentation yeast, Saccharomyces cerevisiae, was not isolated. Drosophila flies are preferentially associated with different yeast species in the vineyard and winery environments, and this association may help the movement and dispersal of yeast species in the vineyard and winery ecosystem.

  17. Measuring Drosophila (fruit fly) activity during microgravity exposure.

    PubMed

    Miller, M S; Keller, T S

    1999-07-01

    Important advances in the understanding of the aging process could be obtained through comprehension of the changes experienced by Drosophila melanogaster (fruit flies) during microgravity. Previous experiments flown on Cosmos satellites and various Space Shuttle missions have shown a significant decrease in the life span of young male Drosophila after microgravity exposure. Additionally, postflight analysis indicated an accelerated aging of the microgravity exposed male flies since they exhibited a significant decrease in mating ability and a consistently lower negative geotaxis response than the 1 g ground controls. The negative geotaxis response is the Drosophila's reaction to move opposite to the Earth's gravitational vector when disturbed in certain manners. Researchers have hypothesized that the accelerated aging, is due to an increased locomotor activity which causes a subsequent increase in mitochondrial activity. The increased mitochondrial activity, in turn, causes increased aging through accelerated damage to the mitochondrial system. An increase in locomotor activity was indicated by analyzing only a fraction (1/6th of a second) of the 15 minute video recordings of groups of Drosophila taken approximately every two days during a 14-day Space Shuttle flight. The increased locomotor activity may be related to the Drosophila's negative geotaxis response in that the flies may be reacting to the absence of normal gravity by continuously searching for the gravity vector. The aims of this study are to develop methods to accurately measure individual Drosophila activity, use these derived methods in 1 g to create a Drosophila activity baseline, and use the methods during short and long duration microgravity exposure (sounding rockets, parabolic flights, Space Shuttle, International Space Station, etc.) to examine Drosophila activity. The role of the negative geotaxis response on locomotor activity will be examined by using two strains of behaviorally selected

  18. Evidence for horizontal transfer of Wolbachia by a Drosophila mite.

    PubMed

    Brown, Amy N; Lloyd, Vett K

    2015-07-01

    Mites are common ectoparasites of Drosophila and have been implicated in bacterial and mobile element invasion of Drosophila stocks. The obligate endobacterium, Wolbachia, has widespread effects on gene expression in their arthropod hosts and alters host reproduction to enhance its survival and propagation, often with deleterious effects in Drosophila hosts. To determine whether Wolbachia could be transferred between Drosophila melanogaster laboratory stocks by the mite Tyrophagus putrescentiae, mites were introduced to Wolbachia-infected Drosophila vials. These vials were kept adjacent to mite-free and Wolbachia-uninfected Drosophila stock vials. The Wolbachia infection statuses of the infected and uninfected flies were checked from generation 1 to 5. Results indicate that Wolbachia DNA could be amplified from mites infesting Wolbachia-infected fly stocks and infection in the previously uninfected stocks arose within generation 1 or 2, concomitant with invasion of mites from the Wolbachia-infected stock. A possible mechanism for the transfer of Wolbachia from flies to mites and vice versa, can be inferred from time-lapse photography of fly and mite interactions. We demonstrated that mites ingest Drosophila corpses, including Wolbachia-infected corpses, and Drosophila larva ingest mites, providing possible sources of Wolbachia infection and transfer. This research demonstrated that T. putrescentiae white mites can facilitate Wolbachia transfer between Drosophila stocks and that this may occur by ingestion of infected corpses. Mite-vectored Wolbachia transfer allows for rapid establishment of Wolbachia infection within a new population. This mode of Wolbachia introduction may be relevant in nature as well as in the laboratory, and could have a variety of biological consequences.

  19. A novel, tissue-specific, Drosophila homeobox gene.

    PubMed Central

    Barad, M; Jack, T; Chadwick, R; McGinnis, W

    1988-01-01

    The homeobox gene family of Drosophila appears to control a variety of position-specific patterning decisions during embryonic and imaginal development. Most of these patterning decisions determine groups of cells on the anterior-posterior axis of the Drosophila germ band. We have isolated a novel homeobox gene from Drosophila, designated H2.0. H2.0 has the most diverged homeobox so far characterized in metazoa, and, in contrast to all previously isolated homeobox genes, H2.0 exhibits a tissue-specific pattern of expression. The cells that accumulate transcripts for this novel gene correspond to the visceral musculature and its anlagen. Images PMID:2901348

  20. [Regulatory functions of Pax gene family in Drosophila development].

    PubMed

    Li, Li; Yang, Yang; Xue, Lei

    2010-02-01

    The Pax gene family encodes a group of important transcription factors that have been evolutionary conserved from Drosophila to human. Pax genes play pivotal roles in regulating diverse signal transduction pathways and organogenesis during embryonic development through modulating cell proliferation and self-renewal, embryonic precursor cell migration, and the coordination of specific differentiation programs. Ten members of the Pax gene family, which perform crucial regulatory functions during embryonic and postembryonic development, have been identified in Drosophila. In this report, we described the protein structures, expression patterns, and main functions of Drosophila Pax genes.

  1. Insulin/IGF signaling and its regulation in Drosophila.

    PubMed

    Nässel, Dick R; Liu, Yiting; Luo, Jiangnan

    2015-09-15

    Taking advantage of Drosophila as a genetically tractable experimental animal much progress has been made in our understanding of how the insulin/IGF signaling (IIS) pathway regulates development, growth, metabolism, stress responses and lifespan. The role of IIS in regulation of neuronal activity and behavior has also become apparent from experiments in Drosophila. This review briefly summarizes these functional roles of IIS, and also how the insulin producing cells (IPCs) are regulated in the fly. Furthermore, we discuss functional aspects of the spatio-temporal production of eight different insulin-like peptides (DILP1-8) that are thought to act on one known receptor (dInR) in Drosophila.

  2. Spatial control of the actin cytoskeleton in Drosophila epithelial cells.

    PubMed

    Baum, B; Perrimon, N

    2001-10-01

    The actin cytoskeleton orders cellular space and transduces many of the forces required for morphogenesis. Here we combine genetics and cell biology to identify genes that control the polarized distribution of actin filaments within the Drosophila follicular epithelium. We find that profilin and cofilin regulate actin-filament formation throughout the cell cortex. In contrast, CAP-a Drosophila homologue of Adenylyl Cyclase Associated Proteins-functions specifically to limit actin-filament formation catalysed by Ena at apical cell junctions. The Abl tyrosine kinase also collaborates in this process. We therefore propose that CAP, Ena and Abl act in concert to modulate the subcellular distribution of actin filaments in Drosophila.

  3. Genetic effects of plutonium in Drosophila. Final technical report

    SciTech Connect

    1995-07-01

    This three year project, initiated in 1987, involved the genetic effects of alpha radiations on Drosophila. This document represents the final technical report. Plutonium residue was used as the alpha source of radon gas. Spontaneous mutation frequency in the Drosophila stock was very low. In the experiments using alpha radiation from radon gas, radiation doses as low as 20R induced significant numbers of mutations, with higher numbers of mutations at higher doses. If X-ray induced mutation frequencies reported in the literature are used for comparison, it can be concluded that alpha radiation from radon gas induces at least 2 to 3 time more mutations in Drosophila.

  4. The Berkeley Drosophila Genome Project gene disruption project: Single P-element insertions mutating 25% of vital Drosophila genes.

    PubMed Central

    Spradling, A C; Stern, D; Beaton, A; Rhem, E J; Laverty, T; Mozden, N; Misra, S; Rubin, G M

    1999-01-01

    A fundamental goal of genetics and functional genomics is to identify and mutate every gene in model organisms such as Drosophila melanogaster. The Berkeley Drosophila Genome Project (BDGP) gene disruption project generates single P-element insertion strains that each mutate unique genomic open reading frames. Such strains strongly facilitate further genetic and molecular studies of the disrupted loci, but it has remained unclear if P elements can be used to mutate all Drosophila genes. We now report that the primary collection has grown to contain 1045 strains that disrupt more than 25% of the estimated 3600 Drosophila genes that are essential for adult viability. Of these P insertions, 67% have been verified by genetic tests to cause the associated recessive mutant phenotypes, and the validity of most of the remaining lines is predicted on statistical grounds. Sequences flanking >920 insertions have been determined to exactly position them in the genome and to identify 376 potentially affected transcripts from collections of EST sequences. Strains in the BDGP collection are available from the Bloomington Stock Center and have already assisted the research community in characterizing >250 Drosophila genes. The likely identity of 131 additional genes in the collection is reported here. Our results show that Drosophila genes have a wide range of sensitivity to inactivation by P elements, and provide a rationale for greatly expanding the BDGP primary collection based entirely on insertion site sequencing. We predict that this approach can bring >85% of all Drosophila open reading frames under experimental control. PMID:10471706

  5. A Drosophila ABC Transporter Regulates Lifespan

    PubMed Central

    Huang, He; Lu-Bo, Ying; Haddad, Gabriel G.

    2014-01-01

    MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling. PMID:25474322

  6. Homeostatic plasticity at the Drosophila neuromuscular junction.

    PubMed

    Frank, C Andrew

    2014-03-01

    In biology, homeostasis refers to how cells maintain appropriate levels of activity. This concept underlies a balancing act in the nervous system. Synapses require flexibility (i.e. plasticity) to adjust to environmental challenges. Yet there must also exist regulatory mechanisms that constrain activity within appropriate physiological ranges. An abundance of evidence suggests that homeostatic regulation is critical in this regard. In recent years, important progress has been made toward identifying molecules and signaling processes required for homeostatic forms of neuroplasticity. The Drosophila melanogaster third instar larval neuromuscular junction (NMJ) has been an important experimental system in this effort. Drosophila neuroscientists combine genetics, pharmacology, electrophysiology, imaging, and a variety of molecular techniques to understand how homeostatic signaling mechanisms take shape at the synapse. At the NMJ, homeostatic signaling mechanisms couple retrograde (muscle-to-nerve) signaling with changes in presynaptic calcium influx, changes in the dynamics of the readily releasable vesicle pool, and ultimately, changes in presynaptic neurotransmitter release. Roles in these processes have been demonstrated for several molecules and signaling systems discussed here. This review focuses primarily on electrophysiological studies or data. In particular, attention is devoted to understanding what happens when NMJ function is challenged (usually through glutamate receptor inhibition) and the resulting homeostatic responses. A significant area of study not covered in this review, for the sake of simplicity, is the homeostatic control of synapse growth, which naturally, could also impinge upon synapse function in myriad ways. This article is part of the Special Issue entitled 'Homeostatic Synaptic Plasticity'.

  7. Identification of a Drosophila activin receptor.

    PubMed Central

    Childs, S R; Wrana, J L; Arora, K; Attisano, L; O'Connor, M B; Massagué, J

    1993-01-01

    Activins are cytokines of the transforming growth factor beta superfamily that control various events during vertebrate embryo development and cell differentiation in the adult, and act through transmembrane receptors that contain a cytoplasmic protein-serine/threonine kinase domain. We describe the identification, deduced primary structure, and expression pattern of Atr-II, a receptor serine/threonine kinase found in Drosophila. With the exception of the spacing of 10 cysteine residues, the extracellular domain of Atr-II is very dissimilar from those of vertebrate activin receptors, yet it binds activin with high affinity and specificity. The kinase domain sequence of Atr-II is 60% identical to those of activin receptors from vertebrates, suggesting similarities in their signaling mechanisms. Maternal Atr-II transcript and its product are abundant in the oocyte. During development, the highest levels of Atr-II transcript and protein are observed in the mesoderm and gut. The possible role of an activin signaling system in Drosophila development is discussed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8415726

  8. Genetic analysis of glutamatergic function in Drosophila

    SciTech Connect

    Chase, B.A.; Kankel, D.R.

    1987-01-01

    Neurotransmitters are essential for communication between neurons and hence are vital in the overall integrative functioning of the nervous system. Previous work on acetylcholine metabolism in the fruit fly, Drosophila melanogaster, has also raised the possibility that transmitter metabolism may play a prominent role in either the achievement or maintenance of the normal structure of the central nervous system in this species. Unfortunately, acetylcholine is rather poorly characterized as a neurotransmitter in Drosophila; consequently, we have begun an analysis of the role of glutamate (probably the best characterized transmitter in this organism) in the formation and/or maintenance of nervous system structure. We present here the results of a series of preliminary analyses. To suggest where glutamatergic function may be localized, an examination of the spatial distribution of high affinity (/sup 3/H)-glutamate binding sites are presented. We present the results of an analysis of the spatial and temporal distribution of enzymatic activities thought to be important in the regulation of transmitter-glutamate pools (i.e., glutamate oxaloacetic transaminase, glutaminase, and glutamate dehydrogenase). To begin to examine whether mutations in any of these functions are capable of affecting glutamatergic activity, we present the results of an initial genetic analysis of one enzymatic function, glutamate oxaloacetic transaminase (GOT), chosen because of its differential distribution within the adult central nervous system and musculature.

  9. Fascin regulates nuclear actin during Drosophila oogenesis

    PubMed Central

    Kelpsch, Daniel J.; Groen, Christopher M.; Fagan, Tiffany N.; Sudhir, Sweta; Tootle, Tina L.

    2016-01-01

    Drosophila oogenesis provides a developmental system with which to study nuclear actin. During Stages 5–9, nuclear actin levels are high in the oocyte and exhibit variation within the nurse cells. Cofilin and Profilin, which regulate the nuclear import and export of actin, also localize to the nuclei. Expression of GFP-tagged Actin results in nuclear actin rod formation. These findings indicate that nuclear actin must be tightly regulated during oogenesis. One factor mediating this regulation is Fascin. Overexpression of Fascin enhances nuclear GFP-Actin rod formation, and Fascin colocalizes with the rods. Loss of Fascin reduces, whereas overexpression of Fascin increases, the frequency of nurse cells with high levels of nuclear actin, but neither alters the overall nuclear level of actin within the ovary. These data suggest that Fascin regulates the ability of specific cells to accumulate nuclear actin. Evidence indicates that Fascin positively regulates nuclear actin through Cofilin. Loss of Fascin results in decreased nuclear Cofilin. In addition, Fascin and Cofilin genetically interact, as double heterozygotes exhibit a reduction in the number of nurse cells with high nuclear actin levels. These findings are likely applicable beyond Drosophila follicle development, as the localization and functions of Fascin and the mechanisms regulating nuclear actin are widely conserved. PMID:27535426

  10. Drosophila and the hallmarks of cancer.

    PubMed

    Christofi, Theodoulakis; Apidianakis, Yiorgos

    2013-01-01

    : Cancer was the disease of the twentieth century. Today it is still a leading cause of death worldwide despite being intensively investigated. Abundant knowledge exists regarding the pathological and molecular mechanisms that drive healthy cells to become malignant and form metastatic tumors. The relation of oncogenes and tumor suppressors to the genetic trigger of carcinogenesis is unquestionable. However, the development of the disease requires many characteristics that due to their proven role in cancer are collectively described as the "hallmarks of cancer." We highlight here the historic discoveries made using the model organism Drosophila melanogaster and its contributions to biomedical and cancer research. Flies are utilized as a model organism for the investigation of each and every aspect of cancer hallmarks. Due to the significant conservation between flies and mammals at the signaling and tissue physiology level it is possible to explore the genes and mechanisms responsible for cancer pathogenesis in flies. Recent Drosophila studies suggest novel aspects of therapeutic intervention and are expected to guide cancer research in the twenty-first century.

  11. Functional nonequivalence of sperm in Drosophila pseudoobscura.

    PubMed Central

    Snook, R R; Markow, T A; Karr, T L

    1994-01-01

    We report on a form of sperm polymorphism, termed polymegaly, that occurs in species of the Drosophila obscura group. Individual males of species in this group characteristically produce more than one discrete length of nucleated, motile sperm. Hypotheses suggested to explain the evolutionary significance of sperm polymorphism have been either nonadaptive or adaptive, with the latter focusing on sperm competition or nutrient provisioning. These hypotheses assume all sperm types fertilize eggs; however, no data have been gathered to test this assumption. We found that two size classes of sperm are produced and transferred to females in approximately equal numbers by the male; only long sperm persist in significant numbers in female sperm storage organs. Furthermore, we used a DNA-specific dye (bisbenzimide) and sperm-specific antibodies to ask if both sperm types fertilize eggs in Drosophila pseudoobscura. Confocal microscopy and immunofluorescent analyses of fertilized eggs using anti-sperm polyclonal antisera demonstrated that only long sperm participate in fertilization. These data falsify those hypotheses in which all sperm types are assumed to be functionally equivalent (fertilize eggs). Any remaining or new hypotheses for the evolutionary significance of polymegaly must incorporate these findings. Several new areas of research are suggested. Images PMID:7972038

  12. Cellular Mechanisms of Drosophila Heart Morphogenesis

    PubMed Central

    Vogler, Georg; Bodmer, Rolf

    2015-01-01

    Many of the major discoveries in the fields of genetics and developmental biology have been made using the fruit fly, Drosophila melanogaster. With regard to heart development, the conserved network of core cardiac transcription factors that underlies cardiogenesis has been studied in great detail in the fly, and the importance of several signaling pathways that regulate heart morphogenesis, such as Slit/Robo, was first shown in the fly model. Recent technological advances have led to a large increase in the genomic data available from patients with congenital heart disease (CHD). This has highlighted a number of candidate genes and gene networks that are potentially involved in CHD. To validate genes and genetic interactions among candidate CHD-causing alleles and to better understand heart formation in general are major tasks. The specific limitations of the various cardiac model systems currently employed (mammalian and fish models) provide a niche for the fly model, despite its evolutionary distance to vertebrates and humans. Here, we review recent advances made using the Drosophila embryo that identify factors relevant for heart formation. These underline how this model organism still is invaluable for a better understanding of CHD. PMID:26236710

  13. Hox genes and brain development in Drosophila.

    PubMed

    Reichert, Heinrich; Bello, Bruno

    2010-01-01

    Hox genes are prominently expressed in the developing brain and ventral ganglia of Drosophila. In the embryonic brain, the Hox genes labial and Deformed are essential for the establishment of regionalized neuronal identity; in their absence cells are generated in the brain but fail to acquire appropriate neuronal features. Genetic analyses reveal that Hox proteins are largely equivalent in their action in embryonic brain development and that their expression is under the control of cross-regulatory interactions among Hox genes that are similar to those found in embryogenesis of trunk segments. Hox genes have a different role in postembryonic brain development. During the larval phase of CNS development, reactivation of specific Hox genes terminates neural proliferation by induction of apoptotic cell death in neural stem cell-like progenitors called neuroblasts. This reactivation process is tightly controlled by epigenetic mechanisms requiring the Polycomb group of genes. Many features of Hox gene action in Drosophila brain development are evolutionarily conserved and are manifest in brain development of vertebrates.

  14. Acid sensing by the Drosophila olfactory system.

    PubMed

    Ai, Minrong; Min, Soohong; Grosjean, Yael; Leblanc, Charlotte; Bell, Rati; Benton, Richard; Suh, Greg S B

    2010-12-02

    The odour of acids has a distinct quality that is perceived as sharp, pungent and often irritating. How acidity is sensed and translated into an appropriate behavioural response is poorly understood. Here we describe a functionally segregated population of olfactory sensory neurons in the fruitfly, Drosophila melanogaster, that are highly selective for acidity. These olfactory sensory neurons express IR64a, a member of the recently identified ionotropic receptor (IR) family of putative olfactory receptors. In vivo calcium imaging showed that IR64a+ neurons projecting to the DC4 glomerulus in the antennal lobe are specifically activated by acids. Flies in which the function of IR64a+ neurons or the IR64a gene is disrupted had defects in acid-evoked physiological and behavioural responses, but their responses to non-acidic odorants remained unaffected. Furthermore, artificial stimulation of IR64a+ neurons elicited avoidance responses. Taken together, these results identify cellular and molecular substrates for acid detection in the Drosophila olfactory system and support a labelled-line mode of acidity coding at the periphery.

  15. Past1 Modulates Drosophila Eye Development

    PubMed Central

    Dorot, Orly; Steller, Hermann; Segal, Daniel; Horowitz, Mia

    2017-01-01

    Endocytosis is a multi-step process involving a large number of proteins, both general factors, such as clathrin and adaptor protein complexes, and unique proteins, which modulate specialized endocytic processes, like the EHD proteins. EHDs are a family of Eps15 Homology Domain containing proteins that consists of four mammalian homologs, one C. elegans, one Drosophila melanogaster and two plants orthologs. These membrane-associated proteins are involved in different steps of endocytic trafficking pathways. We have previously shown that the Drosophila EHD ortholog, PAST1, associates predominantly with the plasma membrane. Mutations in Past1 result in defects in endocytosis, male sterility, temperature sensitivity and premature death of the flies. Also, Past1 genetically interacts with Notch. In the present study, we investigated the role of PAST1 in the developing fly eye. In mutant flies lacking PAST1, abnormal differentiation of photoreceptors R1, R6 and R7 was evident, with partial penetrance. Likewise, five cone cells were present instead of four. Expression of transgenic PAST1 resulted in a dominant negative effect, with a phenotype similar to that of the deletion mutant, and appearance of additional inter-ommatidial pigment cells. Our results strongly suggest a role for PAST1 in differentiation of photoreceptors R1/R6/R7 and cone cells of the fly ommatidia. PMID:28060904

  16. A Protein Complex Network of Drosophila melanogaster

    PubMed Central

    Guruharsha, K. G.; Rual, J. -F.; Zhai, B.; Mintseris, J.; Vaidya, P.; Vaidya, N.; Beekman, C.; Wong, C.; Rhee, D. Y.; Cenaj, O.; McKillip, E.; Shah, S.; Stapleton, M.; Wan, K. H.; Yu, C.; Parsa, B.; Carlson, J. W.; Chen, X.; Kapadia, B.; VijayRaghavan, K.; Gygi, S. P.; Celniker, S. E.; Obar, R. A.; Artavanis-Tsakonas, S.

    2011-01-01

    SUMMARY Determining the composition of protein complexes is an essential step towards understanding the cell as an integrated system. Using co-affinity purification coupled to mass spectrometry analysis, we examined protein associations involving nearly five thousand individual, FLAG-HA epitope-tagged Drosophila proteins. Stringent analysis of these data, based on a novel statistical framework to define individual protein-protein interactions, led to the generation of a Drosophila Protein interaction Map (DPiM) encompassing 556 protein complexes. The high quality of DPiM and its usefulness as a paradigm for metazoan proteomes is apparent from the recovery of many known complexes, significant enrichment for shared functional attributes and validation in human cells. DPiM defines potential novel members for several important protein complexes and assigns functional links to 586 protein-coding genes lacking previous experimental annotation. DPiM represents, to our knowledge, the largest metazoan protein complex map and provides a valuable resource for analysis of protein complex evolution. PMID:22036573

  17. Drosophila roadblock and Chlamydomonas Lc7

    PubMed Central

    Bowman, Aaron B.; Patel-King, Ramila S.; Benashski, Sharon E.; McCaffery, J. Michael; Goldstein, Lawrence S.B.; King, Stephen M.

    1999-01-01

    Eukaryotic organisms utilize microtubule-dependent motors of the kinesin and dynein superfamilies to generate intracellular movement. To identify new genes involved in the regulation of axonal transport in Drosophila melanogaster, we undertook a screen based upon the sluggish larval phenotype of known motor mutants. One of the mutants identified in this screen, roadblock (robl), exhibits diverse defects in intracellular transport including axonal transport and mitosis. These defects include intra-axonal accumulations of cargoes, severe axonal degeneration, and aberrant chromosome segregation. The gene identified by robl encodes a 97–amino acid polypeptide that is 57% identical (70% similar) to the 105–amino acid Chlamydomonas outer arm dynein–associated protein LC7, also reported here. Both robl and LC7 have homology to several other genes from fruit fly, nematode, and mammals, but not Saccharomyces cerevisiae. Furthermore, we demonstrate that members of this family of proteins are associated with both flagellar outer arm dynein and Drosophila and rat brain cytoplasmic dynein. We propose that roadblock/LC7 family members may modulate specific dynein functions. PMID:10402468

  18. Imaging fictive locomotor patterns in larval Drosophila

    PubMed Central

    Bayley, Timothy G.; Taylor, Adam L.; Berni, Jimena; Bate, Michael; Hedwig, Berthold

    2015-01-01

    We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca2+ indicators. The Ca2+ signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca2+ signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca2+ signals were normally initiated did not eliminate production of Ca2+ waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques. PMID:26311188

  19. Contribution of Drosophila TRPA1 to Metabolism

    PubMed Central

    Lee, Jung-Eun; Kim, Yunjung; Kim, Kyoung Heon

    2016-01-01

    Transient receptor potential (TRP) cation channels are highly conserved in humans and insects. Some of these channels are expressed in internal organs and their functions remain incompletely understood. By direct knock-in of the GAL4 gene into the trpA1 locus in Drosophila, we identified the expression of this gene in the subesophageal ganglion (SOGs) region. In addition, the neurites present in the dorsal posterior region as well as the drosophila insulin-like peptide 2 (dILP2)-positive neurons send signals to the SOGs. The signal is sent to the crop, which is an enlarged organ of the esophagus and functions as a storage place for food in the digestive system. To systematically investigate the role of TRPA1 in metabolism, we applied non-targeted metabolite profiling analysis together with gas-chromatography/time-of-flight mass spectrometry, with an aim to identify a wide range of primary metabolites. We effectively captured distinctive metabolomic phenotypes and identified specific metabolic dysregulation triggered by TRPA1 mutation based on reconstructed metabolic network analysis. Primarily, the network analysis pinpointed the simultaneous down-regulation of intermediates in the methionine salvation pathway, in contrast to the synchronized up-regulation of a range of free fatty acids. The gene dosage-dependent dynamics of metabolite levels among wild-type, hetero- and homozygous mutants, and their coordinated metabolic modulation under multiple gene settings across five different genotypes confirmed the direct linkages of TRPA1 to metabolism. PMID:27055172

  20. Molecular Evolution of Phosphoprotein Phosphatases in Drosophila

    PubMed Central

    Miskei, Márton; Ádám, Csaba; Kovács, László; Karányi, Zsolt; Dombrádi, Viktor

    2011-01-01

    Phosphoprotein phosphatases (PPP), these ancient and important regulatory enzymes are present in all eukaryotic organisms. Based on the genome sequences of 12 Drosophila species we traced the evolution of the PPP catalytic subunits and noted a substantial expansion of the gene family. We concluded that the 18–22 PPP genes of Drosophilidae were generated from a core set of 8 indispensable phosphatases that are present in most of the insects. Retropositons followed by tandem gene duplications extended the phosphatase repertoire, and sporadic gene losses contributed to the species specific variations in the PPP complement. During the course of these studies we identified 5, up till now uncharacterized phosphatase retrogenes: PpY+, PpD5+, PpD6+, Pp4+, and Pp6+ which are found only in some ancient Drosophila. We demonstrated that all of these new PPP genes exhibit a distinct male specific expression. In addition to the changes in gene numbers, the intron-exon structure and the chromosomal localization of several PPP genes was also altered during evolution. The G−C content of the coding regions decreased when a gene moved into the heterochromatic region of chromosome Y. Thus the PPP enzymes exemplify the various types of dynamic rearrangements that accompany the molecular evolution of a gene family in Drosophilidae. PMID:21789237

  1. The biology of vision of Drosophila.

    PubMed Central

    Zuker, C S

    1996-01-01

    Phototransduction systems in vertebrates and invertebrates share a great deal of similarity in overall strategy but differ significantly in the underlying molecular machinery. Both are rhodopsin-based G protein-coupled signaling cascades displaying exquisite sensitivity and broad dynamic range. However, light activation of vertebrate photoreceptors leads to activation of a cGMP-phosphodiesterase effector and the generation of a hyperpolarizing response. In contrast, activation of invertebrate photoreceptors, like Drosophila, leads to stimulation of phospholipase C and the generation of a depolarizing receptor potential. The comparative study of these two systems of phototransduction offers the opportunity to understand how similar biological problems may be solved by different molecular mechanisms of signal transduction. The study of this process in Drosophila, a system ideally suited to genetic and molecular manipulation, allows us to dissect the function and regulation of such a complex signaling cascade in its normal cellular environment. In this manuscript I review some of our recent findings and the strategies used to dissect this process. Images Fig. 1 Fig. 4 PMID:8570597

  2. Chromatin signatures of the Drosophila replication program.

    PubMed

    Eaton, Matthew L; Prinz, Joseph A; MacAlpine, Heather K; Tretyakov, George; Kharchenko, Peter V; MacAlpine, David M

    2011-02-01

    DNA replication initiates from thousands of start sites throughout the Drosophila genome and must be coordinated with other ongoing nuclear processes such as transcription to ensure genetic and epigenetic inheritance. Considerable progress has been made toward understanding how chromatin modifications regulate the transcription program; in contrast, we know relatively little about the role of the chromatin landscape in defining how start sites of DNA replication are selected and regulated. Here, we describe the Drosophila replication program in the context of the chromatin and transcription landscape for multiple cell lines using data generated by the modENCODE consortium. We find that while the cell lines exhibit similar replication programs, there are numerous cell line-specific differences that correlate with changes in the chromatin architecture. We identify chromatin features that are associated with replication timing, early origin usage, and ORC binding. Primary sequence, activating chromatin marks, and DNA-binding proteins (including chromatin remodelers) contribute in an additive manner to specify ORC-binding sites. We also generate accurate and predictive models from the chromatin data to describe origin usage and strength between cell lines. Multiple activating chromatin modifications contribute to the function and relative strength of replication origins, suggesting that the chromatin environment does not regulate origins of replication as a simple binary switch, but rather acts as a tunable rheostat to regulate replication initiation events.

  3. Associations of yeasts with spotted-wing Drosophila (Drosophila suzukii; Diptera: Drosophilidae) in cherries and raspberries.

    PubMed

    Hamby, Kelly A; Hernández, Alejandro; Boundy-Mills, Kyria; Zalom, Frank G

    2012-07-01

    A rich history of investigation documents various Drosophila-yeast mutualisms, suggesting that Drosophila suzukii similarly has an association with a specific yeast species or community. To discover candidate yeast species, yeasts were isolated from larval frass, adult midguts, and fruit hosts of D. suzukii. Terminal restriction fragment length polymorphism (TRFLP) technology and decimal dilution plating were used to identify and determine the relative abundance of yeast species present in fruit juice samples that were either infested with D. suzukii or not infested. Yeasts were less abundant in uninfested than infested samples. A total of 126 independent yeast isolates were cultivated from frass, midguts, and fruit hosts of D. suzukii, representing 28 species of yeasts, with Hanseniaspora uvarum predominating. This suggests an association between D. suzukii and H. uvarum that could be utilized for pest management of the highly pestiferous D. suzukii.

  4. Associations of Yeasts with Spotted-Wing Drosophila (Drosophila suzukii; Diptera: Drosophilidae) in Cherries and Raspberries

    PubMed Central

    Hernández, Alejandro; Zalom, Frank G.

    2012-01-01

    A rich history of investigation documents various Drosophila-yeast mutualisms, suggesting that Drosophila suzukii similarly has an association with a specific yeast species or community. To discover candidate yeast species, yeasts were isolated from larval frass, adult midguts, and fruit hosts of D. suzukii. Terminal restriction fragment length polymorphism (TRFLP) technology and decimal dilution plating were used to identify and determine the relative abundance of yeast species present in fruit juice samples that were either infested with D. suzukii or not infested. Yeasts were less abundant in uninfested than infested samples. A total of 126 independent yeast isolates were cultivated from frass, midguts, and fruit hosts of D. suzukii, representing 28 species of yeasts, with Hanseniaspora uvarum predominating. This suggests an association between D. suzukii and H. uvarum that could be utilized for pest management of the highly pestiferous D. suzukii. PMID:22582060

  5. Antibody staining of the central nervous system in adult Drosophila.

    PubMed

    Sweeney, Sean T; Hidalgo, Alicia; de Belle, J Steven; Keshishian, Haig

    2012-02-01

    The Drosophila nervous system provides a valuable model for studying various aspects of brain development and function. The postembryonic Drosophila brain is especially useful, because specific neuron types derive from specific progenitors at specific times. Elucidating the means by which diverse neuron types derive from a limited number of progenitors can contribute significantly to our understanding of the genetic and molecular mechanisms involved in developmental neurobiology. Antibody-labeling techniques are particularly useful for examining the Drosophila brain. These methods generally use primary antibodies specific to a protein or a structure of interest and a fluorescently labeled or enzyme-coupled secondary antibody to detect the primary antibodies. Immunofluorescence methods allow for simultaneous probing for multiple antigens using different fluorophores, as well as high-resolution confocal examination of deep structures. This protocol describes general procedures for antibody labeling of neural tissue from Drosophila, as well as visualization techniques for fluorescent and enzyme-linked probes.

  6. Metallothionein genes in Drosophila melanogaster constitute a dual system.

    PubMed Central

    Mokdad, R; Debec, A; Wegnez, M

    1987-01-01

    We have selected a metallothionein (MT) cDNA clone from a cadmium-resistant Drosophila melanogaster cell line. This clone includes an open reading frame coding for a 43-amino acid protein whose characteristics are a high cysteine content (12 cysteines, 28% of all residues) and a lack of aromatic amino acids. This protein differs markedly from the Drosophila MT (Mtn gene) previously reported [Lastowski-Perry, D., Otto, E. & Maroni, G. (1985) J. Biol. Chem. 260, 1527-1530). The MT system of Drosophila thus consists of at least two distantly related genes, in sharp contrast with vertebrate MT systems, in which the different members of MT gene families display high similarity. The gene corresponding to our MT cDNA (Mto) is inducible in Drosophila cell lines and in both larval and adult flies. Images PMID:3106973

  7. Insights From Natural Host-Parasite Interactions: The Drosophila Model

    PubMed Central

    Keebaugh, Erin S.; Schlenke, Todd A.

    2013-01-01

    Immune responses against opportunistic pathogens have been extensively studied in Drosophila, leading to a detailed map of the genetics behind innate immunity networks including the Toll, Imd, Jak-Stat, and JNK pathways. However, immune mechanisms of other organisms, particularly plants, have primarily been investigated using natural pathogens. It was the use of natural pathogens in plant research that revealed the plant R/Avr system, a specialized immune response derived from antagonistic coevolution between plant immune proteins and their natural pathogens’ virulence proteins. Thus, we recommend that researchers begin to use natural Drosophila pathogens to identify novel immune mechanisms that may have arisen through antagonistic coevolution with common natural pathogens. In this review, we address the benefits of using natural pathogens in research, describe the known natural pathogens of Drosophila, and discuss exciting prospects for future research on select natural pathogens of Drosophila. PMID:23764256

  8. Functional Gustatory Role of Chemoreceptors in Drosophila Wings.

    PubMed

    Raad, Hussein; Ferveur, Jean-François; Ledger, Neil; Capovilla, Maria; Robichon, Alain

    2016-05-17

    Neuroanatomical evidence argues for the presence of taste sensilla in Drosophila wings; however, the taste physiology of insect wings remains hypothetical, and a comprehensive link to mechanical functions, such as flight, wing flapping, and grooming, is lacking. Our data show that the sensilla of the Drosophila anterior wing margin respond to both sweet and bitter molecules through an increase in cytosolic Ca(2+) levels. Conversely, genetically modified flies presenting a wing-specific reduction in chemosensory cells show severe defects in both wing taste signaling and the exploratory guidance associated with chemodetection. In Drosophila, the chemodetection machinery includes mechanical grooming, which facilitates the contact between tastants and wing chemoreceptors, and the vibrations of flapping wings that nebulize volatile molecules as carboxylic acids. Together, these data demonstrate that the Drosophila wing chemosensory sensilla are a functional taste organ and that they may have a role in the exploration of ecological niches.

  9. Conservation of Olfactory Avoidance in Drosophila Species and Identification of Repellents for Drosophila suzukii

    PubMed Central

    Krause Pham, Christine; Ray, Anandasankar

    2015-01-01

    Flying insects use olfaction to navigate towards fruits in complex odor environments with remarkable accuracy. Some fruits change odor profiles substantially during ripening and related species can prefer different stages. In Drosophila species attractive odorants have been studied extensively, but little is understood about the role of avoidance pathways. In order to examine the role of the avoidance cue CO2 emitted from fruit on behavior of two species with different ripening stage preferences, we investigated the CO2-detection pathway in Drosophila melanogaster and Drosophila suzukii, a harmful pest of fruits. Avoidance to CO2 is not conserved in D. suzukii suggesting a behavioral adaptation that could facilitate attraction to younger fruit with higher CO2 emission levels. We investigated known innate avoidance pathways from five species at different evolutionary distances: D. melanogaster, D. yakuba, D. suzukii, D. pseudoobscura and D. virilis. Surprisingly, only DEET shows strong repellency across all species, whereas CO2, citronellal and ethyl 3-hydroxybutyrate show only limited conservation. These findings guide us to test recently discovered safe DEET substitutes, and we identify one that protects fruits from D. suzukii thus providing a new behavioral strategy for controlling agricultural pests. PMID:26098542

  10. Invasive Drosophila suzukii facilitates Drosophila melanogaster infestation and sour rot outbreaks in the vineyards

    PubMed Central

    Guilhot, R.; Xuéreb, A.; Benoit, L.; Chapuis, M. P. ; Gibert, P.

    2017-01-01

    How do invasive pests affect interactions between members of pre-existing agrosystems? The invasive pest Drosophila suzukii is suspected to be involved in the aetiology of sour rot, a grapevine disease that otherwise develops following Drosophila melanogaster infestation of wounded berries. We combined field observations with laboratory assays to disentangle the relative roles of both Drosophila in disease development. We observed the emergence of numerous D. suzukii, but no D. melanogaster flies, from bunches that started showing mild sour rot symptoms days after field collection. However, bunches that already showed severe rot symptoms in the field mostly contained D. melanogaster. In the laboratory, oviposition by D. suzukii triggered sour rot development. An independent assay showed the disease increased grape attractiveness to ovipositing D. melanogaster females. Our results suggest that in invaded vineyards, D. suzukii facilitates D. melanogaster infestation and, consequently, favours sour rot outbreaks. Rather than competing with close species, the invader subsequently permits their reproduction in otherwise non-accessible resources and may cause more frequent, or more extensive, disease outbreaks.

  11. Loss of Drosophila pheromone reverses its role in sexual communication in Drosophila suzukii.

    PubMed

    Dekker, Teun; Revadi, Santosh; Mansourian, Suzan; Ramasamy, Sukanya; Lebreton, Sebastien; Becher, Paul G; Angeli, Sergio; Rota-Stabelli, Omar; Anfora, Gianfranco

    2015-04-07

    The Drosophila pheromone cis-11-octadecenyl acetate (cVA) is used as pheromone throughout the melanogaster group and fulfils a primary role in sexual and social behaviours. Here, we found that Drosophila suzukii, an invasive pest that oviposits in undamaged ripe fruit, does not produce cVA. In fact, its production site, the ejaculatory bulb, is atrophied. Despite loss of cVA production, its receptor, Or67d, and cognate sensillum, T1, which are essential in cVA-mediated behaviours, were fully functional. However, T1 expression was dramatically reduced in D. suzukii, and the corresponding antennal lobe glomerulus, DA1, minute. Behavioural responses to cVA depend on the input balance of Or67d neurons (driving cVA-mediated behaviours) and Or65a neurons (inhibiting cVA-mediated behaviours). Accordingly, the shifted input balance in D. suzukii has reversed cVA's role in sexual behaviour: perfuming D. suzukii males with Drosophila melanogaster equivalents of cVA strongly reduced mating rates. cVA has thus evolved from a generic sex pheromone to a heterospecific signal that disrupts mating in D. suzukii, a saltational shift, mediated through offsetting the input balance that is highly conserved in congeneric species. This study underlines that dramatic changes in a species' sensory preference can result from rather 'simple' numerical shifts in underlying neural circuits.

  12. Drosophila GRAIL: An intelligent system for gene recognition in Drosophila DNA sequences

    SciTech Connect

    Xu, Ying; Einstein, J.R.; Uberbacher, E.C.; Helt, G.; Rubin, G.

    1995-06-01

    An AI-based system for gene recognition in Drosophila DNA sequences was designed and implemented. The system consists of two main modules, one for coding exon recognition and one for single gene model construction. The exon recognition module finds a coding exon by recognition of its splice junctions (or translation start) and coding potential. The core of this module is a set of neural networks which evaluate an exon candidate for the possibility of being a true coding exon using the ``recognized`` splice junction (or translation start) and coding signals. The recognition process consists of four steps: generation of an exon candidate pool, elimination of improbable candidates using heuristic rules, candidate evaluation by trained neural networks, and candidate cluster resolution and final exon prediction. The gene model construction module takes as input the clustered exon candidates and builds a ``best`` possible single gene model using an efficient dynamic programming algorithm. 129 Drosophila sequences consisting of 441 coding exons including 216358 coding bases were extructed from GenBank and used to build statistical matrices and to train the neural networks. On this training set the system recognized 97% of the coding messages and predicted only 5% false messages. Among the ``correctly`` predicted exons, 68% match the actual exon exactly and 96% have at least one edge predicted correctly. On an independent test set consisting of 30 Drosophila sequences, the system recognized 96% of the coding messages and predicted 7% false messages.

  13. FlyBase: a Drosophila database. Flybase Consortium.

    PubMed Central

    1998-01-01

    FlyBase (http://flybase.bio.indiana.edu/) is a comprehensive database of genetic and molecular data concerning Drosophila . FlyBase is maintained as a relational database (in Sybase) and is made available as html documents and flat files. The scope of FlyBase includes: genes, alleles (with phenotypes), aberrations, transposons, pointers to sequence data, gene products, maps, clones, stock lists, Drosophila workers and bibliographic references. PMID:9399806

  14. Molecular mechanisms of metabolic regulation by insulin in Drosophila.

    PubMed

    Teleman, Aurelio A

    2009-12-14

    The insulin signalling pathway is highly conserved from mammals to Drosophila. Insulin signalling in the fly, as in mammals, regulates a number of physiological functions, including carbohydrate and lipid metabolism, tissue growth and longevity. In the present review, I discuss the molecular mechanisms by which insulin signalling regulates metabolism in Drosophila, comparing and contrasting with the mammalian system. I discuss both the intracellular signalling network, as well as the communication between organs in the fly.

  15. Drosophila larvae: Thermal ecology in changing environments

    NASA Astrophysics Data System (ADS)

    Wang, George

    Temperature affects almost all aspects of life. Although much work has been done to assess the impact of temperature on organismal performance, relatively little is known about how organisms behaviorally regulate temperature, how these behaviors effect population fitness, or how changing climate may interact with these behaviors. I explore these questions with the model system Drosophila larvae. Larvae are small, with a low thermal mass and limited capacity for physiological thermoregulation. Mortality is generally high in larvae, with large potential impacts on population growth rate. Thus behavioral thermoregulation in larvae should be of critical selective importance. I present a review of the current knowledge of Drosophila thermal preference. I describe quantifiable thermoregulatory behaviors ( TMV and TW) unique to larvae. I show interspecific variation of these behaviors in Drosophila melanogaster and several close relatives, and intraspecific variation between populations collected from different environments. I also investigate these behaviors in two mutant lines, ssa and biz, to investigate the genetic basis of these behaviors. I show that larval thermoregulatory systems are independent of those of adults. Further these thermoregulatory behaviors differ between two sister species, D. yakuba and D. santomea. Although these two species readily hybridize in laboratory conditions, very few hybrids are observed in the field. The surprising result that hybrids of D. yakuba and D. santomea seem to inherit TMV from D. yakuba suggests a novel extrinsic isolation mechanism between the two species. I explore how fitness is the result of the interaction between genetics and the environment. I utilize Monte Carlo simulation to show how non-linear norms of reaction generate variation in populations even in the absence of behavior or epigenetic evolutionary mechanisms. Finally I investigate the global distribution of temperatures in which these organisms exist using

  16. Functional requirements driving the gene duplication in 12 Drosophila species

    PubMed Central

    2013-01-01

    Background Gene duplication supplies the raw materials for novel gene functions and many gene families arisen from duplication experience adaptive evolution. Most studies of young duplicates have focused on mammals, especially humans, whereas reports describing their genome-wide evolutionary patterns across the closely related Drosophila species are rare. The sequenced 12 Drosophila genomes provide the opportunity to address this issue. Results In our study, 3,647 young duplicate gene families were identified across the 12 Drosophila species and three types of expansions, species-specific, lineage-specific and complex expansions, were detected in these gene families. Our data showed that the species-specific young duplicate genes predominated (86.6%) over the other two types. Interestingly, many independent species-specific expansions in the same gene family have been observed in many species, even including 11 or 12 Drosophila species. Our data also showed that the functional bias observed in these young duplicate genes was mainly related to responses to environmental stimuli and biotic stresses. Conclusions This study reveals the evolutionary patterns of young duplicates across 12 Drosophila species on a genomic scale. Our results suggest that convergent evolution acts on young duplicate genes after the species differentiation and adaptive evolution may play an important role in duplicate genes for adaption to ecological factors and environmental changes in Drosophila. PMID:23945147

  17. The bacterial communities of Drosophila suzukii collected from undamaged cherries.

    PubMed

    Chandler, James Angus; James, Pamela M; Jospin, Guillaume; Lang, Jenna M

    2014-01-01

    Drosophila suzukii is an introduced pest insect that feeds on undamaged, attached fruit. This diet is distinct from the fallen, discomposing fruits utilized by most other species of Drosophila. Since the bacterial microbiota of Drosophila, and of many other animals, is affected by diet, we hypothesized that the bacteria associated with D. suzukii are distinct from that of other Drosophila. Using 16S rDNA PCR and Illumina sequencing, we characterized the bacterial communities of larval and adult D. suzukii collected from undamaged, attached cherries in California, USA. We find that the bacterial communities associated with these samples of D. suzukii contain a high frequency of Tatumella. Gluconobacter and Acetobacter, two taxa with known associations with Drosophila, were also found, although at lower frequency than Tatumella in four of the five samples examined. Sampling D. suzukii from different locations and/or while feeding on different fruits is needed to determine the generality of the results determined by these samples. Nevertheless this is, to our knowledge, the first study characterizing the bacterial communities of this ecologically unique and economically important species of Drosophila.

  18. Sensorimotor structure of Drosophila larva phototaxis.

    PubMed

    Kane, Elizabeth A; Gershow, Marc; Afonso, Bruno; Larderet, Ivan; Klein, Mason; Carter, Ashley R; de Bivort, Benjamin L; Sprecher, Simon G; Samuel, Aravinthan D T

    2013-10-01

    The avoidance of light by fly larvae is a classic paradigm for sensorimotor behavior. Here, we use behavioral assays and video microscopy to quantify the sensorimotor structure of phototaxis using the Drosophila larva. Larval locomotion is composed of sequences of runs (periods of forward movement) that are interrupted by abrupt turns, during which the larva pauses and sweeps its head back and forth, probing local light information to determine the direction of the successive run. All phototactic responses are mediated by the same set of sensorimotor transformations that require temporal processing of sensory inputs. Through functional imaging and genetic inactivation of specific neurons downstream of the sensory periphery, we have begun to map these sensorimotor circuits into the larval central brain. We find that specific sensorimotor pathways that govern distinct light-evoked responses begin to segregate at the first relay after the photosensory neurons.

  19. Mechanosensory neurons control sweet sensing in Drosophila

    PubMed Central

    Jeong, Yong Taek; Oh, Soo Min; Shim, Jaewon; Seo, Jeong Taeg; Kwon, Jae Young; Moon, Seok Jun

    2016-01-01

    Animals discriminate nutritious food from toxic substances using their sense of taste. Since taste perception requires taste receptor cells to come into contact with water-soluble chemicals, it is a form of contact chemosensation. Concurrent with that contact, mechanosensitive cells detect the texture of food and also contribute to the regulation of feeding. Little is known, however, about the extent to which chemosensitive and mechanosensitive circuits interact. Here, we show Drosophila prefers soft food at the expense of sweetness and that this preference requires labellar mechanosensory neurons (MNs) and the mechanosensory channel Nanchung. Activation of these labellar MNs causes GABAergic inhibition of sweet-sensing gustatory receptor neurons, reducing the perceived intensity of a sweet stimulus. These findings expand our understanding of the ways different sensory modalities cooperate to shape animal behaviour. PMID:27641708

  20. Sleep restores behavioral plasticity to Drosophila mutants.

    PubMed

    Dissel, Stephane; Angadi, Veena; Kirszenblat, Leonie; Suzuki, Yasuko; Donlea, Jeff; Klose, Markus; Koch, Zachary; English, Denis; Winsky-Sommerer, Raphaelle; van Swinderen, Bruno; Shaw, Paul J

    2015-05-18

    Given the role that sleep plays in modulating plasticity, we hypothesized that increasing sleep would restore memory to canonical memory mutants without specifically rescuing the causal molecular lesion. Sleep was increased using three independent strategies: activating the dorsal fan-shaped body, increasing the expression of Fatty acid binding protein (dFabp), or by administering the GABA-A agonist 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridine-3-ol (THIP). Short-term memory (STM) or long-term memory (LTM) was evaluated in rutabaga (rut) and dunce (dnc) mutants using aversive phototaxic suppression and courtship conditioning. Each of the three independent strategies increased sleep and restored memory to rut and dnc mutants. Importantly, inducing sleep also reverses memory defects in a Drosophila model of Alzheimer's disease. Together, these data demonstrate that sleep plays a more fundamental role in modulating behavioral plasticity than previously appreciated and suggest that increasing sleep may benefit patients with certain neurological disorders.

  1. Diversity and dynamics of the Drosophila transcriptome

    PubMed Central

    Boley, Nathan; Eisman, Robert; May, Gemma E.; Stoiber, Marcus H.; Duff, Michael O.; Booth, Ben W.; Wen, Jiayu; Park, Soo; Suzuki, Ana Maria; Wan, Kenneth H.; Yu, Charles; Zhang, Dayu; Carlson, Joseph W.; Cherbas, Lucy; Eads, Brian D.; Miller, David; Mockaitis, Keithanne; Roberts, Johnny; Davis, Carrie A.; Frise, Erwin; Hammonds, Ann S.; Olson, Sara; Shenker, Sol; Sturgill, David; Samsonova, Anastasia A.; Weiszmann, Richard; Robinson, Garret; Hernandez, Juan; Andrews, Justen; Bickel, Peter J.; Carninci, Piero; Cherbas, Peter; Gingeras, Thomas R.; Hoskins, Roger A.; Kaufman, Thomas C.; Lai, Eric C.; Oliver, Brian; Perrimon, Norbert

    2014-01-01

    Animal transcriptomes are dynamic, each cell type, tissue and organ system expressing an ensemble of transcript isoforms that give rise to substantial diversity. We identified new genes, transcripts, and proteins using poly(A)+ RNA sequence from Drosophila melanogaster cultured cell lines, dissected organ systems, and environmental perturbations. We found a small set of mostly neural-specific genes has the potential to encode thousands of transcripts each through extensive alternative promoter usage and RNA splicing. The magnitudes of splicing changes are larger between tissues than between developmental stages, and most sex-specific splicing is gonad-specific. Gonads express hundreds of previously unknown coding and long noncoding RNAs (lncRNAs) some of which are antisense to protein-coding genes and produce short regulatory RNAs. Furthermore, previously identified pervasive intergenic transcription occurs primarily within newly identified introns. The fly transcriptome is substantially more complex than previously recognized arising from combinatorial usage of promoters, splice sites, and polyadenylation sites. PMID:24670639

  2. Studying cytokinesis in Drosophila epithelial tissues.

    PubMed

    Pinheiro, D; Bellaïche, Y

    2017-01-01

    Epithelial tissue cohesiveness is ensured through cell-cell junctions that maintain both adhesion and mechanical coupling between neighboring cells. During development, epithelial tissues undergo intensive cell proliferation. Cell division, and particularly cytokinesis, is coupled to the formation of new adhesive contacts, thereby preserving tissue integrity and propagating cell polarity. Remarkably, the geometry of the new interfaces is determined by the combined action of the dividing cell and its neighbors. To further understand the interplay between the dividing cell and its neighbors, as well as the role of cell division for tissue morphogenesis, it is important to analyze cytokinesis in vivo. Here we present methods to perform live imaging of cell division in Drosophila epithelial tissues and discuss some aspects of image processing and analysis.

  3. Sexual deprivation increases ethanol intake in Drosophila.

    PubMed

    Shohat-Ophir, G; Kaun, K R; Azanchi, R; Mohammed, H; Heberlein, U

    2012-03-16

    The brain's reward systems reinforce behaviors required for species survival, including sex, food consumption, and social interaction. Drugs of abuse co-opt these neural pathways, which can lead to addiction. Here, we used Drosophila melanogaster to investigate the relationship between natural and drug rewards. In males, mating increased, whereas sexual deprivation reduced, neuropeptide F (NPF) levels. Activation or inhibition of the NPF system in turn reduced or enhanced ethanol preference. These results thus link sexual experience, NPF system activity, and ethanol consumption. Artificial activation of NPF neurons was in itself rewarding and precluded the ability of ethanol to act as a reward. We propose that activity of the NPF-NPF receptor axis represents the state of the fly reward system and modifies behavior accordingly.

  4. Sensorimotor structure of Drosophila larva phototaxis

    PubMed Central

    Kane, Elizabeth A.; Gershow, Marc; Afonso, Bruno; Larderet, Ivan; Klein, Mason; Carter, Ashley R.; de Bivort, Benjamin L.; Sprecher, Simon G.; Samuel, Aravinthan D. T.

    2013-01-01

    The avoidance of light by fly larvae is a classic paradigm for sensorimotor behavior. Here, we use behavioral assays and video microscopy to quantify the sensorimotor structure of phototaxis using the Drosophila larva. Larval locomotion is composed of sequences of runs (periods of forward movement) that are interrupted by abrupt turns, during which the larva pauses and sweeps its head back and forth, probing local light information to determine the direction of the successive run. All phototactic responses are mediated by the same set of sensorimotor transformations that require temporal processing of sensory inputs. Through functional imaging and genetic inactivation of specific neurons downstream of the sensory periphery, we have begun to map these sensorimotor circuits into the larval central brain. We find that specific sensorimotor pathways that govern distinct light-evoked responses begin to segregate at the first relay after the photosensory neurons. PMID:24043822

  5. Antioxidants, metabolic rate and aging in Drosophila

    NASA Technical Reports Server (NTRS)

    Miquel, J.; Fleming, J.; Economos, A. C.

    1982-01-01

    The metabolic rate-of-living theory of aging was investigated by determining the effect of several life-prolonging antioxidants on the metabolic rate and life span of Drosophila. The respiration rate of groups of continuously agitated flies was determined in a Gilson respirometer. Vitamin E, 2,4-dinitrophenol, nordihydroguaiaretic acid, and thiazolidine carboxylic acid were employed as antioxidants. Results show that all of these antioxidants reduced the oxygen consumption rate and increased the mean life span, and a significant negative linear correlation was found between the mean life span and the metabolic rate. It is concluded that these findings indicate that some antioxidants may inhibit respiration rate in addition to their protective effect against free radical-induced cellular damage.

  6. Control of apoptosis by Drosophila DCAF12.

    PubMed

    Hwangbo, Dae-Sung; Biteau, Benoit; Rath, Sneha; Kim, Jihyun; Jasper, Heinrich

    2016-05-01

    Regulated Apoptosis (Programmed Cell Death, PCD) maintains tissue homeostasis in adults, and ensures proper growth and morphogenesis of tissues during development of metazoans. Accordingly, defects in cellular processes triggering or executing apoptotic programs have been implicated in a variety of degenerative and neoplastic diseases. Here, we report the identification of DCAF12, an evolutionary conserved member of the WD40-motif repeat family of proteins, as a new regulator of apoptosis in Drosophila. We find that DCAF12 is required for Diap1 cleavage in response to pro-apoptotic signals, and is thus necessary and sufficient for RHG (Reaper, Hid, and Grim)-mediated apoptosis. Loss of DCAF12 perturbs the elimination of supernumerary or proliferation-impaired cells during development, and enhances tumor growth induced by loss of neoplastic tumor suppressors, highlighting the wide requirement for DCAF12 in PCD.

  7. Phosphoproteome Analysis of Drosophila melanogaster Embryos

    PubMed Central

    Zhai, Bo; Villén, Judit; Beausoleil, Sean A.; Mintseris, Julian; Gygi, Steven P.

    2011-01-01

    Protein phosphorylation is a key regulatory event in most cellular processes and development. Mass spectrometry-based proteomics provides a framework for the large-scale identification and characterization of phosphorylation sites. Here, we used a well-established phosphopeptide enrichment and identification strategy including the combination of strong cation exchange chromatography, immobilized metal affinity chromatography, and high-accuracy mass spectrometry instrumentation to study phosphorylation in developing Drosophila embryos. In total, 13 720 different phosphorylation sites were discovered from 2702 proteins with an estimated false-discovery rate (FDR) of 0.63% at the peptide level. Because of the large size of the data set, both novel and known phosphorylation motifs were extracted using the Motif-X algorithm, including those representative of potential ordered phosphorylation events. PMID:18327897

  8. Drosophila Genotype Influences Commensal Bacterial Levels

    PubMed Central

    Shanmugarajah, Niroshan; Buchon, Nicolas; Clark, Andrew G.

    2017-01-01

    Host genotype can influence the composition of the commensal bacterial community in some organisms. Composition, however, is only one parameter describing a microbial community. Here, we test whether a second parameter—abundance of bacteria—is a heritable trait by quantifying the presence of four commensal bacterial strains within 36 gnotobiotic inbred lines of Drosophila melanogaster. We find that D. melanogaster genotype exerts a significant effect on microbial levels within the fly. When introduced as monocultures into axenic flies, three of the four bacterial strains were reliably detected within the fly. The amounts of these different strains are strongly correlated, suggesting that the host regulates commensal bacteria through general, not bacteria-specific, means. While the correlation does not appear to be driven by simple variation in overall gut dimensions, a genetic association study suggests that variation in commensal bacterial load may largely be attributed to physical aspects of host cell growth and development. PMID:28095502

  9. Cytoplasmic Streaming in the Drosophila Oocyte.

    PubMed

    Quinlan, Margot E

    2016-10-06

    Objects are commonly moved within the cell by either passive diffusion or active directed transport. A third possibility is advection, in which objects within the cytoplasm are moved with the flow of the cytoplasm. Bulk movement of the cytoplasm, or streaming, as required for advection, is more common in large cells than in small cells. For example, streaming is observed in elongated plant cells and the oocytes of several species. In the Drosophila oocyte, two stages of streaming are observed: relatively slow streaming during mid-oogenesis and streaming that is approximately ten times faster during late oogenesis. These flows are implicated in two processes: polarity establishment and mixing. In this review, I discuss the underlying mechanism of streaming, how slow and fast streaming are differentiated, and what we know about the physiological roles of the two types of streaming.

  10. Mechanosensory neurons control sweet sensing in Drosophila.

    PubMed

    Jeong, Yong Taek; Oh, Soo Min; Shim, Jaewon; Seo, Jeong Taeg; Kwon, Jae Young; Moon, Seok Jun

    2016-09-19

    Animals discriminate nutritious food from toxic substances using their sense of taste. Since taste perception requires taste receptor cells to come into contact with water-soluble chemicals, it is a form of contact chemosensation. Concurrent with that contact, mechanosensitive cells detect the texture of food and also contribute to the regulation of feeding. Little is known, however, about the extent to which chemosensitive and mechanosensitive circuits interact. Here, we show Drosophila prefers soft food at the expense of sweetness and that this preference requires labellar mechanosensory neurons (MNs) and the mechanosensory channel Nanchung. Activation of these labellar MNs causes GABAergic inhibition of sweet-sensing gustatory receptor neurons, reducing the perceived intensity of a sweet stimulus. These findings expand our understanding of the ways different sensory modalities cooperate to shape animal behaviour.

  11. Genetic control of Drosophila nerve cord development

    NASA Technical Reports Server (NTRS)

    Skeath, James B.; Thor, Stefan

    2003-01-01

    The Drosophila ventral nerve cord has been a central model system for studying the molecular genetic mechanisms that control CNS development. Studies show that the generation of neural diversity is a multistep process initiated by the patterning and segmentation of the neuroectoderm. These events act together with the process of lateral inhibition to generate precursor cells (neuroblasts) with specific identities, distinguished by the expression of unique combinations of regulatory genes. The expression of these genes in a given neuroblast restricts the fate of its progeny, by activating specific combinations of downstream genes. These genes in turn specify the identity of any given postmitotic cell, which is evident by its cellular morphology and choice of neurotransmitter.

  12. Drosophila TRP channels and animal behavior.

    PubMed

    Fowler, Melissa A; Montell, Craig

    2013-03-19

    Multiple classes of cell surface receptors and ion channels participate in the detection of changes in environmental stimuli, and thereby influence animal behavior. Among the many classes of ion channels, Transient Receptor Potential (TRP) cation channels are notable in contributing to virtually every sensory modality, and in controlling a daunting array of behaviors. TRP channels appear to be conserved in all metazoan organisms including worms, insects and humans. Flies encode 13 TRPs, most of which are expressed and function in sensory neurons, and impact behaviors ranging from phototaxis to thermotaxis, gravitaxis, the avoidance of noxious tastants and smells and proprioception. Multiple diseases result from defects in TRPs, and flies provide an excellent animal model for dissecting the mechanisms underlying "TRPopathies." Drosophila TRPs also function in the sensation of botanically derived insect repellents, and related TRPs in insect pests are potential targets for the development of improved repellents to combat insect-borne diseases.

  13. Epigenetic regulation of transcription in Drosophila.

    PubMed

    Swaminathan, Aishwarya; Gajan, Ambikai; Pile, Lori A

    2012-01-01

    Post-translational modification of histones is a major mechanism of epigenetic regulation of eukaryotic transcription. Drosophila has proven to be an important model system for the study of histone modifying enzymes and the cross talk that occurs between the various modifications. Polytene chromosome analysis and genome-wide chromatin immunoprecipitation (ChIP) studies have provided much insight into the location of marks and many of the enzymes that perform the catalytic reactions. Gene specific effects have been determined through study of flies carrying mutations in histone modifying enzymes. This review will highlight classic studies and present recent progress on both the localization data and mutant analyses. This information has been used to assign function to the marks and to the enzymes that place or remove them, critical for the process of transcriptional regulation.

  14. Transplantation of Nuclei in Drosophila melanogaster

    PubMed Central

    Zalokar, Marko

    1971-01-01

    Nuclei surrounded by ooplasm of the syncytial stage of developing eggs of wild-type Drosophila melanogaster were implanted into freshly laid fertilized eggs of females of a y w stock. More than half of the recipient eggs produced larvae, but few of the larvae hatched or developed further. The best sets of experiments gave about twelve percent of imagos, mostly y w in appearance. Several larvae were mosaics with yellow Malpighian tubes, and two flies had part of the abdominal segments of the wild type. Half of the flies were fertile, but they produced only y w offspring, except for two males that had y w appearance, but wild-type gonads. When crossed with y w females, they gave wild-type females and y w males. Images PMID:5283944

  15. Peroxiredoxin 5 modulates immune response in Drosophila

    PubMed Central

    Radyuk, Svetlana N.; Michalak, Katarzyna; Klichko, Vladimir I.; Benes, Judith; Orr, William C.

    2010-01-01

    Background Peroxiredoxins are redox-sensing enzymes with multiple cellular functions. Previously, we reported on the potent antioxidant function of Drosophila peroxiredoxin 5 (dPrx5). Studies with mammalian and human cells suggest that peroxiredoxins can modulate immune-related signaling. Methods Survivorship studies and bacteriological analysis were used to determine resistance of flies to fungal and bacterial infections. RT-PCR and immunoblot analyses determined expression of dPrx5 and immunity factors in response to bacterial challenge. Double mutants for dprx5 gene and genes comprising the Imd/Relish and dTak1/Basket branches of the immune signaling pathways were used in epistatic analysis. Results The dprx5 mutant flies were more resistant to bacterial infection than controls, while flies overexpressing dPrx5 were more susceptible. The enhanced resistance to bacteria was accompanied by rapid induction of the Imd-dependent antimicrobial peptides, phosphorylation of the JNK kinase Basket and altered transcriptional profiling of the transient response genes, puckered, ets21C and relish, while the opposite effects were observed in flies over-expressing dPrx5. Epistatic analysis of double mutants, using attacin D and Puckered as read outs of activation of the Imd and JNK pathways, implicated dPrx5 function in the control of the dTak1-JNK arm of immune signaling. Conclusions Differential effects on fly survivorship suggested a trade-off between the antioxidant and immune functions of dPrx5. Molecular and epistatic analyses identified dPrx5 as a negative regulator in the dTak1-JNK arm of immune signaling. General significance Our findings suggest that peroxiredoxins play an important modulatory role in the Drosophila immune response. PMID:20600624

  16. Modeling Spinal Muscular Atrophy in Drosophila

    PubMed Central

    Mukherjee, Ashim; Kankel, Mark W.; Sen, Anindya; Sridhar, Vasanthi; Fulga, Tudor A.; Hart, Anne C.; Van Vactor, David; Artavanis-Tsakonas, Spyros

    2008-01-01

    Spinal Muscular Atrophy (SMA), a recessive hereditary neurodegenerative disease in humans, has been linked to mutations in the survival motor neuron (SMN) gene. SMA patients display early onset lethality coupled with motor neuron loss and skeletal muscle atrophy. We used Drosophila, which encodes a single SMN ortholog, survival motor neuron (Smn), to model SMA, since reduction of Smn function leads to defects that mimic the SMA pathology in humans. Here we show that a normal neuromuscular junction (NMJ) structure depends on SMN expression and that SMN concentrates in the post-synaptic NMJ regions. We conducted a screen for genetic modifiers of an Smn phenotype using the Exelixis collection of transposon-induced mutations, which affects approximately 50% of the Drosophila genome. This screen resulted in the recovery of 27 modifiers, thereby expanding the genetic circuitry of Smn to include several genes not previously known to be associated with this locus. Among the identified modifiers was wishful thinking (wit), a type II BMP receptor, which was shown to alter the Smn NMJ phenotype. Further characterization of two additional members of the BMP signaling pathway, Mothers against dpp (Mad) and Daughters against dpp (Dad), also modify the Smn NMJ phenotype. The NMJ defects caused by loss of Smn function can be ameliorated by increasing BMP signals, suggesting that increased BMP activity in SMA patients may help to alleviate symptoms of the disease. These results confirm that our genetic approach is likely to identify bona fide modulators of SMN activity, especially regarding its role at the neuromuscular junction, and as a consequence, may identify putative SMA therapeutic targets. PMID:18791638

  17. Genetic effects on heavy ions in drosophila

    NASA Technical Reports Server (NTRS)

    Kale, P. G.

    1986-01-01

    Drosophila sex-linked recessive lethal mutation test was used to study the dose response relation and relative biological effectiveness of heavy ions. The experiments were performed using the heavy ion beams at BEVALAC of Lawrence Berkeley Laboratory. These experiments were undertaken according to the proposed milestones and included Ne-20, A-40 and Fe-65 ions with respective energies of 600 MeV, 840 MeV and 850 MeV. At these energies several doses of these radiations ranging from 20 to 1280 R were used. Space radiation exposure to astronauts is supposed to be quite low and therefore very low dose experiments i.e., 20 R, were also performed for the three ions. The mutation response was measured in all germ cell types i.e., spermatozoa, spermatids, spermatocytes and spermatogonia of treated Drosophila males. A linear dose frequency relation was observed for most of the range except at high doses where the saturation effect was observed. Also, a very significant difference was observed among the sensitivity of the four germ cell stages where spermatozoa and spermatids were more sensitive. At the higher doses of this range, most of the spermatogonia and spermatocytes were killed. Although comparative and identical experiments with X-rays or neutrons have not been performed, the compassion of our data with the ones available in literature suggest that the heavy ions have a high rbe and that they are several times more effective than low LET X-rays. The rbe compared to neutrons however appears to be only slightly higher.

  18. Ancient Anxiety Pathways Influence Drosophila Defense Behaviors.

    PubMed

    Mohammad, Farhan; Aryal, Sameer; Ho, Joses; Stewart, James Charles; Norman, Nurul Ayuni; Tan, Teng Li; Eisaka, Agnese; Claridge-Chang, Adam

    2016-04-04

    Anxiety helps us anticipate and assess potential danger in ambiguous situations [1-3]; however, the anxiety disorders are the most prevalent class of psychiatric illness [4-6]. Emotional states are shared between humans and other animals [7], as observed by behavioral manifestations [8], physiological responses [9], and gene conservation [10]. Anxiety research makes wide use of three rodent behavioral assays-elevated plus maze, open field, and light/dark box-that present a choice between sheltered and exposed regions [11]. Exposure avoidance in anxiety-related defense behaviors was confirmed to be a correlate of rodent anxiety by treatment with known anxiety-altering agents [12-14] and is now used to characterize anxiety systems. Modeling anxiety with a small neurogenetic animal would further aid the elucidation of its neuronal and molecular bases. Drosophila neurogenetics research has elucidated the mechanisms of fundamental behaviors and implicated genes that are often orthologous across species. In an enclosed arena, flies stay close to the walls during spontaneous locomotion [15, 16], a behavior proposed to be related to anxiety [17]. We tested this hypothesis with manipulations of the GABA receptor, serotonin signaling, and stress. The effects of these interventions were strikingly concordant with rodent anxiety, verifying that these behaviors report on an anxiety-like state. Application of this method was able to identify several new fly anxiety genes. The presence of conserved neurogenetic pathways in the insect brain identifies Drosophila as an attractive genetic model for the study of anxiety and anxiety-related disorders, complementing existing rodent systems.

  19. Ancient Anxiety Pathways Influence Drosophila Defense Behaviors

    PubMed Central

    Mohammad, Farhan; Aryal, Sameer; Ho, Joses; Stewart, James Charles; Norman, Nurul Ayuni; Tan, Teng Li; Eisaka, Agnese; Claridge-Chang, Adam

    2016-01-01

    Summary Anxiety helps us anticipate and assess potential danger in ambiguous situations [1, 2, 3]; however, the anxiety disorders are the most prevalent class of psychiatric illness [4, 5, 6]. Emotional states are shared between humans and other animals [7], as observed by behavioral manifestations [8], physiological responses [9], and gene conservation [10]. Anxiety research makes wide use of three rodent behavioral assays—elevated plus maze, open field, and light/dark box—that present a choice between sheltered and exposed regions [11]. Exposure avoidance in anxiety-related defense behaviors was confirmed to be a correlate of rodent anxiety by treatment with known anxiety-altering agents [12, 13, 14] and is now used to characterize anxiety systems. Modeling anxiety with a small neurogenetic animal would further aid the elucidation of its neuronal and molecular bases. Drosophila neurogenetics research has elucidated the mechanisms of fundamental behaviors and implicated genes that are often orthologous across species. In an enclosed arena, flies stay close to the walls during spontaneous locomotion [15, 16], a behavior proposed to be related to anxiety [17]. We tested this hypothesis with manipulations of the GABA receptor, serotonin signaling, and stress. The effects of these interventions were strikingly concordant with rodent anxiety, verifying that these behaviors report on an anxiety-like state. Application of this method was able to identify several new fly anxiety genes. The presence of conserved neurogenetic pathways in the insect brain identifies Drosophila as an attractive genetic model for the study of anxiety and anxiety-related disorders, complementing existing rodent systems. PMID:27020741

  20. Temperature representation in the Drosophila brain

    PubMed Central

    Frank, Dominic D.; Jouandet, Genevieve C.; Kearney, Patrick J.; Macpherson, Lindsey J.; Gallio, Marco

    2015-01-01

    SUMMARY In Drosophila, rapid temperature changes are detected at the periphery by dedicated receptors forming a simple sensory map for hot and cold in the brain1. However, flies show a host of complex innate and learned responses to temperature, indicating that they are able to extract a range of information from this simple input. Here, we define the anatomical and physiological repertoire for temperature representation in the Drosophila brain. First, we use a photolabeling strategy2 to trace the connections that relay peripheral thermosensory information to higher brain centers, and show that they largely converge onto three target regions: the Mushroom Body, Lateral Horn (well-known centers for sensory processing) and the Posterior Lateral Protocerebrum, a region we now define as a major site of thermosensory representation. Then, using in vivo calcium imaging3, we describe the thermosensory projection neurons selectively activated by hot or cold stimuli. Fast-adapting neurons display transient “ON” and “OFF” responses and track rapid temperature shifts remarkably well, while slow-adapting cell responses better reflect the magnitude of simple thermal changes. Unexpectedly, we also find a population of ‘broadly-tuned’ cells that respond to both heating and cooling, and show that they are required for normal behavioral avoidance of both hot and cold in a simple 2-choice temperature preference assay. Taken together, our results uncover a coordinated ensemble of neural responses to temperature in the fly brain, demonstrate that a broadly tuned thermal-line contributes to rapid avoidance behavior, and illustrate how stimulus quality, temporal structure, and intensity can be extracted from a simple glomerular map at a single synaptic station. PMID:25739506

  1. The Evolution of Olfactory Gene Families in Drosophila and the Genomic Basis of chemical-Ecological Adaptation in Drosophila suzukii

    PubMed Central

    Ramasamy, Sukanya; Ometto, Lino; Crava, Cristina M.; Revadi, Santosh; Kaur, Rupinder; Horner, David S.; Pisani, Davide; Dekker, Teun; Anfora, Gianfranco; Rota-Stabelli, Omar

    2016-01-01

    How the evolution of olfactory genes correlates with adaption to new ecological niches is still a debated topic. We explored this issue in Drosophila suzukii, an emerging model that reproduces on fresh fruit rather than in fermenting substrates like most other Drosophila. We first annotated the repertoire of odorant receptors (ORs), odorant binding proteins (OBPs), and antennal ionotropic receptors (aIRs) in the genomes of two strains of D. suzukii and of its close relative Drosophila biarmipes. We then analyzed these genes on the phylogeny of 14 Drosophila species: whereas ORs and OBPs are characterized by higher turnover rates in some lineages including D. suzukii, aIRs are conserved throughout the genus. Drosophila suzukii is further characterized by a non-random distribution of OR turnover on the gene phylogeny, consistent with a change in selective pressures. In D. suzukii, we found duplications and signs of positive selection in ORs with affinity for short-chain esters, and loss of function of ORs with affinity for volatiles produced during fermentation. These receptors—Or85a and Or22a—are characterized by divergent alleles in the European and American genomes, and we hypothesize that they may have been replaced by some of the duplicated ORs in corresponding neurons, a hypothesis reciprocally confirmed by electrophysiological recordings. Our study quantifies the evolution of olfactory genes in Drosophila and reveals an array of genomic events that can be associated with the ecological adaptations of D. suzukii. PMID:27435796

  2. Multi-state Comparison of Attractants for Monitoring Drosophila suzukii (Diptera: Drosophilidae) in Blueberries and Caneberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii, also referred to as the spotted wing drosophila, has recently and dramatically expanded its global range with significant consequences for its primary host crops: blueberries, blackberries, raspberries, cherries, and strawberries. D. suzukii populations can increase quickly, and ...

  3. Inhibition of mitochondrial calcium uptake 1 in Drosophila neurons.

    PubMed

    M'Angale, P G; Staveley, B E

    2017-02-08

    The mitochondrial calcium uptake 1 (MICU1) is a regulatory subunit of the mitochondrial calcium uniporter that plays an important role in calcium sensing. It contains two EF-hand domains that are well conserved across diverse species from protozoa to plants and metazoans. The loss of MICU1 function in mammals is attributed to several neurological disorders that involve movement dysfunction. The CG4495 gene in Drosophila melanogaster was identified as a putative homolog of MICU1 in the HomoloGene database of the National Centre for Biotechnology Information (NCBI). In agreement with previous studies that have shown the development of neurological disorders and movement defects in MICU1 loss-of-function organisms, we attempted to identify the function of CG4495/MICU1 in Drosophila neurons. We analyzed survival and locomotor ability of these flies and additionally performed biometric analysis of the Drosophila developing eye. The inducible RNA interference-mediated inhibition of CG4495/MICU1 in the Ddc-Gal4-expressing neurons of Drosophila presented with reduction in survival coupled with a precocious loss of locomotor ability. Since the pro-survival Bcl-2 family genes have been shown to be protective towards mitochondria, and CG4495/MICU1 has a mitochondrial targeting sequence, we attempted to rescue the phenotypes resulting from the inhibition of CG4495/MICU1 by overexpressing Buffy, the sole Bcl-2 homologue in Drosophila. The co-expression of CG4495/MICU1-RNAi along with Buffy resulted in the suppression of the phenotypes induced by the inhibition of CG4495/MICU1. Subsequently, the inhibition of CG4495/MICU1 in the Drosophila developing eye, a neuron-rich organ, resulted in reduced number of ommatidia and a highly fused ommatidial array. These developmental eye defects were rescued by the overexpression of Buffy. Our study suggests an important role for MICU1 in the normal function of neurons in Drosophila.

  4. The Dopaminergic System in the Aging Brain of Drosophila

    PubMed Central

    White, Katherine E.; Humphrey, Dickon M.; Hirth, Frank

    2010-01-01

    Drosophila models of Parkinson's disease are characterized by two principal phenotypes: the specific loss of dopaminergic (DA) neurons in the aging brain and defects in motor behavior. However, an age-related analysis of these baseline parameters in wildtype Drosophila is lacking. Here we analyzed the DA system and motor behavior in aging Drosophila. DA neurons in the adult brain can be grouped into bilateral symmetric clusters, each comprising a stereotypical number of cells. Analysis of TH > mCD8::GFP and cell type-specific MARCM clones revealed that DA neurons show cluster-specific, stereotypical projection patterns with terminal arborization in target regions that represent distinct functional areas of the adult brain. Target areas include the mushroom bodies, involved in memory formation and motivation, and the central complex, involved in the control of motor behavior, indicating that similar to the mammalian brain, DA neurons in the fly brain are involved in the regulation of specific behaviors. Behavioral analysis revealed that Drosophila show an age-related decline in startle-induced locomotion and negative geotaxis. Motion tracking however, revealed that walking activity, and exploration behavior, but not centrophobism increase at late stages of life. Analysis of TH > Dcr2, mCD8::GFP revealed a specific effect of Dcr2 expression on walking activity but not on exploratory or centrophobic behavior, indicating that the siRNA pathway may modulate distinct DA behaviors in Drosophila. Moreover, DA neurons were maintained between early- and late life, as quantified by TH > mCD8::GFP and anti-TH labeling, indicating that adult onset, age-related degeneration of DA neurons does not occur in the aging brain of Drosophila. Taken together, our data establish baseline parameters in Drosophila for the study of Parkinson's disease as well as other disorders affecting DA neurons and movement control. PMID:21165178

  5. A practical method for culturing and novel biology of the spotted wing Drosophila (Diptera: Drosophilidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The non-saprophagous vinegar fly, Drosophila suzukii (Mats.) or the spotted wing Drosophila (SWD), is a global berry pest that is rearable on a standard Drosophila diet containing the fly’s own natural food: soft-skinned berries. Techniques presented here can help curb bacterial and fungal disease o...

  6. NOVEL ASPECTS OF SPOTTED WING DROSOPHILA BIOLOGY AND IMPROVED METHODS OF REARING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii (Mats.) or the spotted wing Drosophila (SWD), is a global pest of soft fruits that can now be reared on a standard Drosophila diet containing the fly's own natural food: soft-skinned berries. The techniques tested here can thwart bacterial and fungal disease that can destroy more ...

  7. big bang gene modulates gut immune tolerance in Drosophila.

    PubMed

    Bonnay, François; Cohen-Berros, Eva; Hoffmann, Martine; Kim, Sabrina Y; Boulianne, Gabrielle L; Hoffmann, Jules A; Matt, Nicolas; Reichhart, Jean-Marc

    2013-02-19

    Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases.

  8. Intestinal stem cells in the adult Drosophila midgut

    SciTech Connect

    Jiang, Huaqi; Edgar, Bruce A.

    2011-11-15

    Drosophila has long been an excellent model organism for studying stem cell biology. Notably, studies of Drosophila's germline stem cells have been instrumental in developing the stem cell niche concept. The recent discovery of somatic stem cells in adult Drosophila, particularly the intestinal stem cells (ISCs) of the midgut, has established Drosophila as an exciting model to study stem cell-mediated adult tissue homeostasis and regeneration. Here, we review the major signaling pathways that regulate the self-renewal, proliferation and differentiation of Drosophila ISCs, discussing how this regulation maintains midgut homeostasis and mediates regeneration of the intestinal epithelium after injury. -- Highlights: Black-Right-Pointing-Pointer The homeostasis and regeneration of adult fly midguts are mediated by ISCs. Black-Right-Pointing-Pointer Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). Black-Right-Pointing-Pointer EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. Black-Right-Pointing-Pointer Notch signaling regulates ISC self-renewal and differentiation.

  9. Comparative transcriptomic analysis of human and Drosophila extracellular vesicles

    PubMed Central

    Lefebvre, Fabio Alexis; Benoit Bouvrette, Louis Philip; Perras, Lilyanne; Blanchet-Cohen, Alexis; Garnier, Delphine; Rak, Janusz; Lécuyer, Éric

    2016-01-01

    Extracellular vesicles (EVs) are membrane-enclosed nanoparticles containing specific repertoires of genetic material. In mammals, EVs can mediate the horizontal transfer of various cargos and signaling molecules, notably miRNA and mRNA species. Whether this form of intercellular communication prevails in other metazoans remains unclear. Here, we report the first parallel comparative morphologic and transcriptomic characterization of EVs from Drosophila and human cellular models. Electronic microscopy revealed that human and Drosophila cells release similar EVs with diameters ranging from 30 to 200 nm, which contain complex populations of transcripts. RNA-seq identified abundant ribosomal RNAs, related pseudogenes and retrotransposons in human and Drosophila EVs. Vault RNAs and Y RNAs abounded in human samples, whereas small nucleolar RNAs involved in pseudouridylation were most prevalent in Drosophila EVs. Numerous mRNAs were identified, largely consisting of exonic sequences displaying full-length read coverage and enriched for translation and electronic transport chain functions. By analogy with human systems, these sizeable similarities suggest that EVs could potentially enable RNA-mediated intercellular communication in Drosophila. PMID:27282340

  10. Retinoids regulate a developmental checkpoint for tissue regeneration in Drosophila

    PubMed Central

    Halme, Adrian; Cheng, Michelle; Hariharan, Iswar K.

    2010-01-01

    Summary Drosophila melanogaster larvae have a remarkable capacity for regenerative growth: Damage to their imaginal discs, the larval precursors of adult structures, elicits a robust proliferative response from the surviving tissue [1–4]. However, as in other organisms, developmental progression and differentiation can restrict regenerative capacity of Drosophila tissues. Experiments in Drosophila and other holometabolous insects have demonstrated that either damage to imaginal tissues [5, 6] or transplantation of a damaged imaginal disc [7, 8] delays the onset of metamorphosis, a time when the imaginal discs undergo morphogenesis and differentiation into their adult structures. Therefore, in Drosophila there appears to be a mechanism that senses tissue damage and extends the larval phase to coordinate tissue regeneration with the overall developmental program of the organism. However, how such a pathway functions remains unknown. Here we demonstrate that a developmental checkpoint extends larval growth after imaginal disc damage by inhibiting the transcription of the gene encoding PTTH, a neuropeptide that promotes the release of the steroid hormone ecdysone. Using a genetic screen, we identify a previously unsuspected role for retinoid biosynthesis in regulating PTTH expression and delaying development in response to tissue damage. Retinoid signaling plays an important, but poorly defined role in several vertebrate regeneration models [9–11]. Our findings demonstrate that retinoid biosynthesis in Drosophila is important for the maintenance of a permissive condition for regenerative growth. PMID:20189388

  11. Transmembrane channel-like (tmc) gene regulates Drosophila larval locomotion

    PubMed Central

    Guo, Yanmeng; Wang, Yuping; Zhang, Wei; Meltzer, Shan; Zanini, Damiano; Yu, Yue; Li, Jiefu; Cheng, Tong; Guo, Zhenhao; Wang, Qingxiu; Jacobs, Julie S.; Sharma, Yashoda; Eberl, Daniel F.; Göpfert, Martin C.; Jan, Lily Yeh; Jan, Yuh Nung; Wang, Zuoren

    2016-01-01

    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. PMID:27298354

  12. Single nucleotide polymorphism markers for genetic mapping in Drosophila melanogaster

    SciTech Connect

    Hoskins, Roger A.; Phan, Alexander C.; Naeemuddin, Mohammed; Mapa, Felipa A.; Ruddy, David A.; Ryan, Jessica J.; Young, Lynn M.; Wells, Trent; Kopczynski, Casey; Ellis, Michael C.

    2001-04-16

    For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that have recently revolutionized human, mouse and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila using an STS-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that the genome. The majority of these markers are single nucleotide polymorphisms (SNPs) and sequences for these variants are provided in an accessible format. The average density of the new markers is 1 marker per 225 kb on the autosomes and 1 marker per 1 Mb on the X chromosome. We include in this survey a set of P-element strains that provide additional utility for high-resolution mapping. We demonstrate one application of the new markers in a simple set of crosses to map a mutation in the hedgehog gene to an interval of <1 Mb. This new map resource significantly increases the efficiency and resolution of recombination mapping and will be of immediate value to the Drosophila research community.

  13. Bioimage Informatics in the context of Drosophila research.

    PubMed

    Jug, Florian; Pietzsch, Tobias; Preibisch, Stephan; Tomancak, Pavel

    2014-06-15

    Modern biological research relies heavily on microscopic imaging. The advanced genetic toolkit of Drosophila makes it possible to label molecular and cellular components with unprecedented level of specificity necessitating the application of the most sophisticated imaging technologies. Imaging in Drosophila spans all scales from single molecules to the entire populations of adult organisms, from electron microscopy to live imaging of developmental processes. As the imaging approaches become more complex and ambitious, there is an increasing need for quantitative, computer-mediated image processing and analysis to make sense of the imagery. Bioimage Informatics is an emerging research field that covers all aspects of biological image analysis from data handling, through processing, to quantitative measurements, analysis and data presentation. Some of the most advanced, large scale projects, combining cutting edge imaging with complex bioimage informatics pipelines, are realized in the Drosophila research community. In this review, we discuss the current research in biological image analysis specifically relevant to the type of systems level image datasets that are uniquely available for the Drosophila model system. We focus on how state-of-the-art computer vision algorithms are impacting the ability of Drosophila researchers to analyze biological systems in space and time. We pay particular attention to how these algorithmic advances from computer science are made usable to practicing biologists through open source platforms and how biologists can themselves participate in their further development.

  14. Drosophila adult and larval pheromones modulate larval food choice

    PubMed Central

    Farine, Jean-Pierre; Cortot, Jérôme; Ferveur, Jean-François

    2014-01-01

    Insects use chemosensory cues to feed and mate. In Drosophila, the effect of pheromones has been extensively investigated in adults, but rarely in larvae. The colonization of natural food sources by Drosophila buzzatii and Drosophila simulans species may depend on species-specific chemical cues left in the food by larvae and adults. We identified such chemicals in both species and measured their influence on larval food preference and puparation behaviour. We also tested compounds that varied between these species: (i) two larval volatile compounds: hydroxy-3-butanone-2 and phenol (predominant in D. simulans and D. buzzatii, respectively), and (ii) adult cuticular hydrocarbons (CHs). Drosophila buzzatii larvae were rapidly attracted to non-CH adult conspecific cues, whereas D. simulans larvae were strongly repulsed by CHs of the two species and also by phenol. Larval cues from both species generally reduced larval attraction and pupariation on food, which was generally—but not always—low, and rarely reflected larval response. As these larval and adult pheromones specifically influence larval food search and the choice of a pupariation site, they may greatly affect the dispersion and survival of Drosophila species in nature. PMID:24741012

  15. Temporal Stability of Molecular Diversity Measures in Natural Populations of Drosophila pseudoobscura and Drosophila persimilis

    PubMed Central

    Hish, Alexander J.; Noor, Mohamed A. F.

    2015-01-01

    Many molecular ecological and evolutionary studies sample wild populations at a single point in time, but that data represents genetic variation from a potentially unrepresentative snapshot in time. Variation across time in genetic parameters may occur quickly in species that produce multiple generations of offspring per year. Here, we compare genetic diversity in wild caught populations of Drosophila persimilis and Drosophila pseudoobscura collected 16 years apart at the same time of year and same site at 4 X-linked and 2 mitochondrial loci to assess genetic stability. We found no major changes in nucleotide diversity in either species, but we observed a drastic shift in Tajima’s D between D. pseudoobscura timepoints at 1 locus associated with increased abundance of a set of related haplotypes. Our data also suggests that D. persimilis may have recently accelerated its demographic expansion. While the changes we observed were modest, this study reinforces the importance of considering potential temporal variation in genetic parameters within single populations over short evolutionary timescales. PMID:25969560

  16. Comparative population genomics of latitudinal variation in Drosophila simulans and Drosophila melanogaster.

    PubMed

    Machado, Heather E; Bergland, Alan O; O'Brien, Katherine R; Behrman, Emily L; Schmidt, Paul S; Petrov, Dmitri A

    2016-02-01

    Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, we find that clinally varying loci in D. simulans are less stable over multiple years than comparable clines in D. melanogaster. D. simulans shows a significantly weaker pattern of isolation by distance than D. melanogaster and we find evidence for a stronger contribution of migration to D. simulans population genetic structure. While population bottlenecks and migration can plausibly explain the differences in stability of clinal variation between the two species, we also observe a significant enrichment of shared clinal genes, suggesting that the selective forces associated with climate are acting on the same genes and phenotypes in D. simulans and D. melanogaster.

  17. Comparative population genomics of latitudinal variation in Drosophila simulans and Drosophila melanogaster

    PubMed Central

    MACHADO, HEATHER E.; BERGLAND, ALAN O.; O’BRIEN, KATHERINE R.; BEHRMAN, EMILY L.; SCHMIDT, PAUL S.; PETROV, DMITRI A.

    2016-01-01

    Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, we find that clinally varying loci in D. simulans are less stable over multiple years than comparable clines in D. melanogaster. D. simulans shows a significantly weaker pattern of isolation by distance than D. melanogaster and we find evidence for a stronger contribution of migration to D. simulans population genetic structure. While population bottlenecks and migration can plausibly explain the differences in stability of clinal variation between the two species, we also observe a significant enrichment of shared clinal genes, suggesting that the selective forces associated with climate are acting on the same genes and phenotypes in D. simulans and D. melanogaster. PMID:26523848

  18. Olfactory memory formation in Drosophila: from molecular to systems neuroscience.

    PubMed

    Davis, Ronald L

    2005-01-01

    The olfactory nervous system of insects and mammals exhibits many similarities, which suggests that the mechanisms for olfactory learning may be shared. Molecular genetic investigations of Drosophila learning have uncovered numerous genes whose gene products are essential for olfactory memory formation. Recent studies of the products of these genes have continued to expand the range of molecular processes known to underlie memory formation. Recent research has also broadened the neuroanatomical areas thought to mediate olfactory learning to include the antennal lobes in addition to a previously accepted and central role for the mushroom bodies. The roles for neurons extrinsic to the mushroom body neurons are becoming better defined. Finally, the genes identified to participate in Drosophila olfactory learning have conserved roles in mammalian organisms, highlighting the value of Drosophila for gene discovery.

  19. Copia Expression Is Variable among Natural Populations of Drosophila

    PubMed Central

    Csink, A. K.; McDonald, J. F.

    1990-01-01

    A survey of copia (retroviral-like element) expression in flies representing 37 populations worldwide of Drosophila melanogaster, Drosophila simulans and Drosophila mauritiana demonstrates that, although copia elements are present in all three species, copia-encoded transcripts are detectable only in D. melanogaster. Levels of copia transcripts vary nearly 100-fold among flies representing geographically diverse populations of D. melanogaster and this variation is not correlated with variability in copia copy number. Analysis of transcript levels in interpopulation hybrids demonstrates that much of this variability may be attributable to the action of trans-acting controls. The geographic and phylogenetic pattern of copia expression suggests that moderate to high levels of copia expression may be a relatively recent evolutionary acquisition. The potential evolutionary significance of these findings is discussed. PMID:1700962

  20. Three-Dimensional Genome Organization and Function in Drosophila

    PubMed Central

    Schwartz, Yuri B.; Cavalli, Giacomo

    2017-01-01

    Understanding how the metazoan genome is used during development and cell differentiation is one of the major challenges in the postgenomic era. Early studies in Drosophila suggested that three-dimensional (3D) chromosome organization plays important regulatory roles in this process and recent technological advances started to reveal connections at the molecular level. Here we will consider general features of the architectural organization of the Drosophila genome, providing historical perspective and insights from recent work. We will compare the linear and spatial segmentation of the fly genome and focus on the two key regulators of genome architecture: insulator components and Polycomb group proteins. With its unique set of genetic tools and a compact, well annotated genome, Drosophila is poised to remain a model system of choice for rapid progress in understanding principles of genome organization and to serve as a proving ground for development of 3D genome-engineering techniques. PMID:28049701

  1. Drosophila melanogaster: a fly through its history and current use.

    PubMed

    Stephenson, R; Metcalfe, N H

    2013-01-01

    Drosophila melanogaster, the common fruit fly, has been used as a model organism in both medical and scientific research for over a century. Work by Thomas Hunt Morgan (1866-1945) and his students at Columbia University at the beginning of the twentieth century led to great discoveries such as sex-linked inheritance and that ionising radiation causes mutations in genes. However, the use of Drosophila was not limited to genetic research. Experimentation with this model organism has also led to discoveries in neuroscience and neurodevelopment, including the basis of circadian rhythms. Its complex nervous system, conserved neurological function, and human disease-related loci allow Drosophila to be an ideal model organism for the study of neurodegenerative disease, for which it is used today, aiding research into diseases such as Alzheimer's and Parkinson's, which are becoming more prevalent in today's ageing population.

  2. Functional reconstitution of Drosophila melanogaster NMJ glutamate receptors

    DOE PAGES

    Han, Tae Hee; Dharkar, Poorva; Mayer, Mark L.; ...

    2015-04-27

    The Drosophila larval neuromuscular junction (NMJ), at which glutamate acts as the excitatory neurotransmitter, is a widely used model for genetic analysis of synapse function and development. Despite decades of study, the inability to reconstitute NMJ glutamate receptor function using heterologous expression systems has complicated the analysis of receptor function, such that it is difficult to resolve the molecular basis for compound phenotypes observed in mutant flies. In this paper, we find that Drosophila Neto functions as an essential component required for the function of NMJ glutamate receptors, permitting analysis of glutamate receptor responses in Xenopus oocytes. Finally, in combinationmore » with a crystallographic analysis of the GluRIIB ligand binding domain, we use this system to characterize the subunit dependence of assembly, channel block, and ligand selectivity for Drosophila NMJ glutamate receptors.« less

  3. RNA editing in Drosophila melanogaster: new targets and functionalconsequences

    SciTech Connect

    Stapleton, Mark; Carlson, Joseph W.; Celniker, Susan E.

    2006-09-05

    Adenosine deaminases that act on RNA (ADARs) catalyze the site-specific conversion of adenosine to inosine in primary mRNA transcripts. These re-coding events affect coding potential, splice-sites, and stability of mature mRNAs. ADAR is an essential gene and studies in mouse, C. elegans, and Drosophila suggest its primary function is to modify adult behavior by altering signaling components in the nervous system. By comparing the sequence of isogenic cDNAs to genomic DNA, we have identified and experimentally verified 27 new targets of Drosophila ADAR. Our analyses lead us to identify new classes of genes whose transcripts are targets of ADAR including components of the actin cytoskeleton, and genes involved in ion homeostasis and signal transduction. Our results indicate that editing in Drosophila increases the diversity of the proteome, and does so in a manner that has direct functional consequences on protein function.

  4. Fat body remodeling and homeostasis control in Drosophila.

    PubMed

    Zheng, Huimei; Yang, Xiaohang; Xi, Yongmei

    2016-12-15

    Remarkable advances have been made in recent years in our understanding of the Drosophila fat body and its functions in energy storage, immune response and nutrient sensing. The fat body interplays with other tissues to respond to the physiological needs of the body's growth and coordinates various metabolic processes at different developmental stages and under different environmental conditions. The identification of various conserved genetic functions and signaling pathways relating to the Drosophila fat body may provide clues to lipometabolic disease and other aspects of tissue remodeling in humans. Here, we discuss recent insights into how regulation of fat body remodeling contributes to hemostasis with a special focus on how signaling networks and internal physiological states shape different aspects of the lipid metabolism in Drosophila.

  5. Mechanical analysis of Drosophila indirect flight and jump muscles

    PubMed Central

    Swank, Douglas M.

    2011-01-01

    The genetic advantages of Drosophila make it a very appealing choice for investigating muscle development, muscle physiology and muscle protein structure and function. To take full advantage of this model organism, it has been vital to develop isolated Drosophila muscle preparations that can be mechanically evaluated. We describe techniques to isolate, prepare and mechanically analyze skinned muscle fibers from two Drosophila muscle types, the indirect flight muscle and the jump muscle. The function of the indirect flight muscle is similar to vertebrate cardiac muscle, to generate power in an oscillatory manner. The indirect flight muscle is ideal for evaluating the influence of protein mutations on muscle and cross-bridge stiffness, oscillatory power, and deriving cross-bridge rate constants. Jump muscle physiology and structure are more similar to skeletal vertebrate muscle than indirect flight muscle, and it is ideal for measuring maximum shortening velocity, force-velocity characteristics and steady-state power generation. PMID:22079350

  6. FlyTED: the Drosophila Testis Gene Expression Database.

    PubMed

    Zhao, Jun; Klyne, Graham; Benson, Elizabeth; Gudmannsdottir, Elin; White-Cooper, Helen; Shotton, David

    2010-01-01

    FlyTED, the Drosophila Testis Gene Expression Database, is a biological research database for gene expression images from the testis of the fruit fly Drosophila melanogaster. It currently contains 2762 mRNA in situ hybridization images and ancillary metadata revealing the patterns of gene expression of 817 Drosophila genes in testes of wild type flies and of seven meiotic arrest mutant strains in which spermatogenesis is defective. This database has been built by adapting a widely used digital library repository software system, EPrints (http://eprints.org/software/), and provides both web-based search and browse interfaces, and programmatic access via an SQL dump, OAI-PMH and SPARQL. FlyTED is available at http://www.fly-ted.org/.

  7. Autophagy in Drosophila: From Historical Studies to Current Knowledge

    PubMed Central

    Mulakkal, Nitha C.; Nagy, Peter; Takats, Szabolcs; Tusco, Radu; Juhász, Gábor; Nezis, Ioannis P.

    2014-01-01

    The discovery of evolutionarily conserved Atg genes required for autophagy in yeast truly revolutionized this research field and made it possible to carry out functional studies on model organisms. Insects including Drosophila are classical and still popular models to study autophagy, starting from the 1960s. This review aims to summarize past achievements and our current knowledge about the role and regulation of autophagy in Drosophila, with an outlook to yeast and mammals. The basic mechanisms of autophagy in fruit fly cells appear to be quite similar to other eukaryotes, and the role that this lysosomal self-degradation process plays in Drosophila models of various diseases already made it possible to recognize certain aspects of human pathologies. Future studies in this complete animal hold great promise for the better understanding of such processes and may also help finding new research avenues for the treatment of disorders with misregulated autophagy. PMID:24949430

  8. Analysis of Cell Cycle Switches in Drosophila Oogenesis.

    PubMed

    Jia, Dongyu; Huang, Yi-Chun; Deng, Wu-Min

    2015-01-01

    The study of Drosophila oogenesis provides invaluable information about signaling pathway regulation and cell cycle programming. During Drosophila oogenesis, a string of egg chambers in each ovariole progressively develops toward maturity. Egg chamber development consists of 14 stages. From stage 1 to stage 6 (mitotic cycle), main-body follicle cells undergo mitotic divisions. From stage 7 to stage 10a (endocycle), follicle cells cease mitosis but continue three rounds of endoreduplication. From stage 10b to stage 13 (gene amplification), instead of whole genome duplication, follicle cells selectively amplify specific genomic regions, mostly for chorion production. So far, Drosophila oogenesis is one of the most well studied model systems used to understand cell cycle switches, which furthers our knowledge about cell cycle control machinery and sheds new light on potential cancer treatments. Here, we give a brief summary of cell cycle switches, the associated signaling pathways and factors, and the detailed experimental procedures used to study the cell cycle switches.

  9. Drosophila as a genetic model for studying pathogenic human viruses.

    PubMed

    Hughes, Tamara T; Allen, Amanda L; Bardin, Joseph E; Christian, Megan N; Daimon, Kansei; Dozier, Kelsey D; Hansen, Caom L; Holcomb, Lisa M; Ahlander, Joseph

    2012-02-05

    Viruses are infectious particles whose viability is dependent on the cells of living organisms, such as bacteria, plants, and animals. It is of great interest to discover how viruses function inside host cells in order to develop therapies to treat virally infected organisms. The fruit fly Drosophila melanogaster is an excellent model system for studying the molecular mechanisms of replication, amplification, and cellular consequences of human viruses. In this review, we describe the advantages of using Drosophila as a model system to study human viruses, and highlight how Drosophila has been used to provide unique insight into the gene function of several pathogenic viruses. We also propose possible directions for future research in this area.

  10. Neuropeptides and Neuropeptide Receptors in the Drosophila melanogaster Genome

    PubMed Central

    Hewes, Randall S.; Taghert, Paul H.

    2001-01-01

    Recent genetic analyses in worms, flies, and mammals illustrate the importance of bioactive peptides in controlling numerous complex behaviors, such as feeding and circadian locomotion. To pursue a comprehensive genetic analysis of bioactive peptide signaling, we have scanned the recently completed Drosophila genome sequence for G protein-coupled receptors sensitive to bioactive peptides (peptide GPCRs). Here we describe 44 genes that represent the vast majority, and perhaps all, of the peptide GPCRs encoded in the fly genome. We also scanned for genes encoding potential ligands and describe 22 bioactive peptide precursors. At least 32 Drosophila peptide receptors appear to have evolved from common ancestors of 15 monophyletic vertebrate GPCR subgroups (e.g., the ancestral gastrin/cholecystokinin receptor). Six pairs of receptors are paralogs, representing recent gene duplications. Together, these findings shed light on the evolutionary history of peptide GPCRs, and they provide a template for physiological and genetic analyses of peptide signaling in Drosophila. PMID:11381038

  11. RNA editing in Drosophila melanogaster: New targets and functional consequences

    PubMed Central

    Carlson, Joseph W.; Celniker, Susan E.

    2006-01-01

    Adenosine deaminases that act on RNA [adenosine deaminase, RNA specific (ADAR)] catalyze the site-specific conversion of adenosine to inosine in primary mRNA transcripts. These re-coding events affect coding potential, splice sites, and stability of mature mRNAs. ADAR is an essential gene, and studies in mouse, Caenorhabditis elegans, and Drosophila suggest that its primary function is to modify adult behavior by altering signaling components in the nervous system. By comparing the sequence of isogenic cDNAs to genomic DNA, we have identified and experimentally verified 27 new targets of Drosophila ADAR. Our analyses led us to identify new classes of genes whose transcripts are targets of ADAR, including components of the actin cytoskeleton and genes involved in ion homeostasis and signal transduction. Our results indicate that editing in Drosophila increases the diversity of the proteome, and does so in a manner that has direct functional consequences on protein function. PMID:17018572

  12. Drosophila as a genetic model for studying pathogenic human viruses

    PubMed Central

    Hughes, Tamara T.; Allen, Amanda L.; Bardin, Joseph E.; Christian, Megan N.; Daimon, Kansei; Dozier, Kelsey D.; Hansen, Caom L.; Holcomb, Lisa M.; Ahlander, Joseph

    2011-01-01

    Viruses are infectious particles whose viability is dependent on the cells of living organisms, such as bacteria, plants, and animals. It is of great interest to discover how viruses function inside host cells in order to develop therapies to treat virally infected organisms. The fruit fly Drosophila melanogaster is an excellent model system for studying the molecular mechanisms of replication, amplification, and cellular consequences of human viruses. In this review, we describe the advantages of using Drosophila as a model system to study human viruses, and highlight how Drosophila has been used to provide unique insight into the gene function of several pathogenic viruses. We also propose possible directions for future research in this area. PMID:22177780

  13. Neuronal polarity in Drosophila: sorting out axons and dendrites

    PubMed Central

    Rolls, Melissa M.

    2014-01-01

    Drosophila neurons have identifiable axons and dendrites based on cell shape, but it is only just starting to become clear how Drosophila neurons are polarized at the molecular level. Dendrite-specific components, including the Golgi complex, GABA receptors, neurotransmitter receptor scaffolding proteins and cell adhesion molecules have been described. And proteins involved in constructing presynaptic specializations are concentrated in axons of some neurons. A very simple model for how these components are distributed to axons and dendrites can be constructed based on the opposite polarity of microtubules in axons and dendrites: dynein carries cargo into dendrites, and kinesins carry cargo into axons. The simple model works well for multipolar neurons, but will likely need refinement for unipolar neurons, which are common in Drosophila. PMID:21557498

  14. Thermal stress depletes energy reserves in Drosophila

    PubMed Central

    Klepsatel, Peter; Gáliková, Martina; Xu, Yanjun; Kühnlein, Ronald P.

    2016-01-01

    Understanding how environmental temperature affects metabolic and physiological functions is of crucial importance to assess the impacts of climate change on organisms. Here, we used different laboratory strains and a wild-caught population of the fruit fly Drosophila melanogaster to examine the effect of temperature on the body energy reserves of an ectothermic organism. We found that permanent ambient temperature elevation or transient thermal stress causes significant depletion of body fat stores. Surprisingly, transient thermal stress induces a lasting “memory effect” on body fat storage, which also reduces survivorship of the flies upon food deprivation later after stress exposure. Functional analyses revealed that an intact heat-shock response is essential to protect flies from temperature-dependent body fat decline. Moreover, we found that the temperature-dependent body fat reduction is caused at least in part by apoptosis of fat body cells, which might irreversibly compromise the fat storage capacity of the flies. Altogether, our results provide evidence that thermal stress has a significant negative impact on organismal energy reserves, which in turn might affect individual fitness. PMID:27641694

  15. Taotie neurons regulate appetite in Drosophila

    PubMed Central

    Zhan, Yin Peng; Liu, Li; Zhu, Yan

    2016-01-01

    The brain has an essential role in maintaining a balance between energy intake and expenditure of the body. Deciphering the processes underlying the decision-making for timely feeding of appropriate amounts may improve our understanding of physiological and psychological disorders related to feeding control. Here, we identify a group of appetite-enhancing neurons in a behavioural screen for flies with increased appetite. Manipulating the activity of these neurons, which we name Taotie neurons, induces bidirectional changes in feeding motivation. Long-term stimulation of Taotie neurons results in flies with highly obese phenotypes. Furthermore, we show that the in vivo activity of Taotie neurons in the neuroendocrine region reflects the hunger/satiety states of un-manipulated animals, and that appetitive-enhancing Taotie neurons control the secretion of insulin, a known regulator of feeding behaviour. Thus, our study reveals a new set of neurons regulating feeding behaviour in the high brain regions that represents physiological hunger states and control feeding behaviour in Drosophila. PMID:27924813

  16. Drosophila melanogaster metallothionein genes: Selection for duplications

    SciTech Connect

    Lange, B.W.

    1989-01-01

    The metallothionein genes of Drosophila melanogaster, Mtn and Mto, may play an important role in heavy-metal detoxification. In order to investigate the possibility of increased selection for duplications of these genes in natural populations exposed to high levels of heavy metals, I compared the frequencies of such duplications among flies collected from metal-contaminated and non-contaminated orchards in Pennsylvania, Tennessee, and Georgia. Contaminated of collection sites and of local flies was confirmed by atomic absorption spectrosphotometry. Six-nucleotide-recognizing restriction enzyme analysis was used to screen 1666 wild third chromosomes for Mtn duplications. A subset (327) of these lines was screened for Mto duplications: none were found. Cadmium tolerance test performed on F{sub 2} progeny of wild females failed to detect a difference in tolerance levels between flies from contaminated orchards and flies from control orchards. Estimates of sequence diversity among a subsample (92) of the chromosomes used in the duplication survey, including all 27 Mtn duplication chromosomes, were obtained using four-nucleotide-recognizing restriction enzyme analysis.

  17. Multiple Drosophila Tracking System with Heading Direction

    PubMed Central

    Sirigrivatanawong, Pudith; Arai, Shogo; Thoma, Vladimiros; Hashimoto, Koichi

    2017-01-01

    Machine vision systems have been widely used for image analysis, especially that which is beyond human ability. In biology, studies of behavior help scientists to understand the relationship between sensory stimuli and animal responses. This typically requires the analysis and quantification of animal locomotion. In our work, we focus on the analysis of the locomotion of the fruit fly Drosophila melanogaster, a widely used model organism in biological research. Our system consists of two components: fly detection and tracking. Our system provides the ability to extract a group of flies as the objects of concern and furthermore determines the heading direction of each fly. As each fly moves, the system states are refined with a Kalman filter to obtain the optimal estimation. For the tracking step, combining information such as position and heading direction with assignment algorithms gives a successful tracking result. The use of heading direction increases the system efficiency when dealing with identity loss and flies swapping situations. The system can also operate with a variety of videos with different light intensities. PMID:28067800

  18. Mechanosensory Interactions Drive Collective Behaviour in Drosophila

    PubMed Central

    Ramdya, Pavan; Lichocki, Pawel; Cruchet, Steeve; Frisch, Lukas; Tse, Winnie; Floreano, Dario; Benton, Richard

    2014-01-01

    Collective behaviour enhances environmental sensing and decision-making in groups of animals1,2. Experimental and theoretical investigations of schooling fish, flocking birds and human crowds have demonstrated that simple interactions between individuals can explain emergent group dynamics3,4. These findings imply the existence of neural circuits that support distributed behaviours, but the molecular and cellular identities of relevant sensory pathways are unknown. Here we show that Drosophila melanogaster exhibits collective responses to an aversive odour: individual flies weakly avoid the stimulus, but groups show enhanced escape reactions. Using high-resolution behavioural tracking, computational simulations, genetic perturbations, neural silencing and optogenetic activation we demonstrate that this collective odour avoidance arises from cascades of appendage touch interactions between pairs of flies. Inter-fly touch sensing and collective behaviour require the activity of distal leg mechanosensory sensilla neurons and the mechanosensory channel NOMPC5,6. Remarkably, through these inter-fly encounters, wild-type flies can elicit avoidance behaviour in mutant animals that cannot sense the odour – a basic form of communication. Our data highlight the unexpected importance of social context in the sensory responses of a solitary species and open the door to a neural circuit level understanding of collective behaviour in animal groups. PMID:25533959

  19. Inbreeding and thermal adaptation in Drosophila subobscura.

    PubMed

    Zivanovic, Goran; Arenas, Conxita; Mestres, Francesc

    2014-09-01

    Using a well-adapted Drosophila subobscura population (Avala, Serbia), a drastic experiment of inbreeding was carried out to assess whether the expected level of homozygosity could be reached or if other evolutionary forces affected the process. In general, no significant changes of inversion (or arrangement) frequencies were detected after 12 brother-sister mating generations. Furthermore, no significant differences were obtained between observed and expected (under the inbreeding model) karyotypic frequencies. Thus, these results seemed to indicate that the main evolutionary factor in the experiment was inbreeding. However, in the G12 generation, complete chromosomal fixation was reached only in two out of the eight final inbred lines. In these lines, the chromosomal compositions were difficult to interpret, but they could be likely a consequence of adaptation to particular laboratory conditions (constant 18 °C, food, light period, etc.). Finally, in a second experiment, the inbred lines presented higher fertility at 18 °C than at 13 °C. Also, there was a significant line effect on fertility: inbred line number 6 (A1, J1, U1+2; U1+2+6, E8, and O3+4+7) presented the highest values, which maybe the result of an adaptation to laboratory conditions. Thus, the results obtained in our experiments reflect the adaptive potential of D. subobscura inversions.

  20. Genetics and genomics of Drosophila mating behavior

    PubMed Central

    Mackay, Trudy F. C.; Heinsohn, Stefanie L.; Lyman, Richard F.; Moehring, Amanda J.; Morgan, Theodore J.; Rollmann, Stephanie M.

    2005-01-01

    The first steps of animal speciation are thought to be the development of sexual isolating mechanisms. In contrast to recent progress in understanding the genetic basis of postzygotic isolating mechanisms, little is known about the genetic architecture of sexual isolation. Here, we have subjected Drosophila melanogaster to 29 generations of replicated divergent artificial selection for mating speed. The phenotypic response to selection was highly asymmetrical in the direction of reduced mating speed, with estimates of realized heritability averaging 7%. The selection response was largely attributable to a reduction in female receptivity. We assessed the whole genome transcriptional response to selection for mating speed using Affymetrix GeneChips and a rigorous statistical analysis. Remarkably, >3,700 probe sets (21% of the array elements) exhibited a divergence in message levels between the Fast and Slow replicate lines. Genes with altered transcriptional abundance in response to selection fell into many different biological process and molecular function Gene Ontology categories, indicating substantial pleiotropy for this complex behavior. Future functional studies are necessary to test the extent to which transcript profiling of divergent selection lines accurately predicts genes that directly affect the selected trait. PMID:15851659

  1. Motor control of Drosophila feeding behavior

    PubMed Central

    Schwarz, Olivia; Bohra, Ali Asgar; Liu, Xinyu; Reichert, Heinrich; VijayRaghavan, Krishnaswamy; Pielage, Jan

    2017-01-01

    The precise coordination of body parts is essential for survival and behavior of higher organisms. While progress has been made towards the identification of central mechanisms coordinating limb movement, only limited knowledge exists regarding the generation and execution of sequential motor action patterns at the level of individual motoneurons. Here we use Drosophila proboscis extension as a model system for a reaching-like behavior. We first provide a neuroanatomical description of the motoneurons and muscles contributing to proboscis motion. Using genetic targeting in combination with artificial activation and silencing assays we identify the individual motoneurons controlling the five major sequential steps of proboscis extension and retraction. Activity-manipulations during naturally evoked proboscis extension show that orchestration of serial motoneuron activation does not rely on feed-forward mechanisms. Our data support a model in which central command circuits recruit individual motoneurons to generate task-specific proboscis extension sequences. DOI: http://dx.doi.org/10.7554/eLife.19892.001 PMID:28211791

  2. A humoral stress response in Drosophila.

    PubMed

    Ekengren, S; Tryselius, Y; Dushay, M S; Liu, G; Steiner, H; Hultmark, D

    2001-05-01

    The ability to react to unfavorable environmental changes is crucial for survival and reproduction, and several adaptive responses to stress have been conserved during evolution [1-3]. Specific immune and heat shock responses mediate the elimination of invading pathogens and of damaged proteins or cells [4-6]. Furthermore, MAP kinases and other signaling factors mediate cellular responses to a very broad range of environmental insults [7-9]. Here we describe a novel systemic response to stress in Drosophila. The Turandot A (TotA) gene encodes a humoral factor, which is secreted from the fat body and accumulates in the body fluids. TotA is strongly induced upon bacterial challenge, as well as by other types of stress such as high temperature, mechanical pressure, dehydration, UV irradiation, and oxidative agents. It is also upregulated during metamorphosis and at high age. Strikingly, flies that overexpress TotA show prolonged survival and retain normal activity at otherwise lethal temperatures. Although TotA is only induced by severe stress, it responds to a much wider range of stimuli than heat shock genes such as hsp70 or immune genes such as Cecropin A1.

  3. Host plant adaptation in Drosophila mettleri populations.

    PubMed

    Castrezana, Sergio; Bono, Jeremy M

    2012-01-01

    The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total). We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea) for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp.) in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts.

  4. Alzheimer's Disease, Drosophila melanogaster and Polyphenols.

    PubMed

    Jimenez-Del-Rio, Marlene; Velez-Pardo, Carlos

    2015-01-01

    Alzheimer's disease (AD) is an insidious neurological disorder that affects memory, one of the human brain's main cognitive functions. Around 5.2 million Americans currently have AD, and the number threatens to climb to 7 million by 2020. Our native country, Colombia, is no exception with an estimated 260,000 individuals to be affected by AD in 2020. A large, genetically-isolated community in Antioquia, Colombia, with early-onset familial Alzheimer's disease due to a presenilin-1 mutation is ideally suited for the study of molecular mechanisms of AD, and hence accelerate the discovery of new or alternative treatment approaches. In this regard, polyphenols--also known as polyhydroxyphenols--have shown antioxidant activity, gene regulation, metal chelator and anti-amyloidogenic aggregation effects. However, further in vitro and in vivo investigations are warranted to validate their use in clinical trials. Drosophila melanogaster is increasingly being used as a valid in vivo model of AD. Here, we summarise data published within the past 16 years (1998-2014) on the molecular biology of AD and the use of polyphenols in the fly to understand the molecular actions and feasibility of these compounds in the treatment of AD.

  5. Caffeine Taste Signaling in Drosophila Larvae

    PubMed Central

    Apostolopoulou, Anthi A.; Köhn, Saskia; Stehle, Bernhard; Lutz, Michael; Wüst, Alexander; Mazija, Lorena; Rist, Anna; Galizia, C. Giovanni; Lüdke, Alja; Thum, Andreas S.

    2016-01-01

    The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal, and ventral organ). However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative co-receptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s). This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviors. PMID:27555807

  6. A Model of Drosophila Larva Chemotaxis.

    PubMed

    Davies, Alex; Louis, Matthieu; Webb, Barbara

    2015-11-01

    Detailed observations of larval Drosophila chemotaxis have characterised the relationship between the odour gradient and the runs, head casts and turns made by the animal. We use a computational model to test whether hypothesised sensorimotor control mechanisms are sufficient to account for larval behaviour. The model combines three mechanisms based on simple transformations of the recent history of odour intensity at the head location. The first is an increased probability of terminating runs in response to gradually decreasing concentration, the second an increased probability of terminating head casts in response to rapidly increasing concentration, and the third a biasing of run directions up concentration gradients through modulation of small head casts. We show that this model can be tuned to produce behavioural statistics comparable to those reported for the larva, and that this tuning results in similar chemotaxis performance to the larva. We demonstrate that each mechanism can enable odour approach but the combination of mechanisms is most effective, and investigate how these low-level control mechanisms relate to behavioural measures such as the preference indices used to investigate larval learning behaviour in group assays.

  7. Active forgetting of olfactory memories in Drosophila.

    PubMed

    Berry, Jacob A; Davis, Ronald L

    2014-01-01

    Failure to remember, or forgetting, is a phenomenon familiar to everyone and despite more than a century of scientific inquiry, why we forget what we once knew remains unclear. If the brain marshals significant resources to form and store memories, why is it that these memories become lost? In the last century, psychological studies have divided forgetting into decay theory, in which memory simply dissipates with time, and interference theory, in which additional learning or mental activity hinders memory by reducing its stability or retrieval (for review, Dewar et al., 2007; Wixted, 2004). Importantly, these psychological models of forgetting posit that forgetting is a passive property of the brain and thus a failure of the brain to retain memories. However, recent neuroscience research on olfactory memory in Drosophila has offered evidence for an alternative conclusion that forgetting is an "active" process, with specific, biologically regulated mechanisms that remove existing memories (Berry et al., 2012; Shuai et al., 2010). Similar to the bidirectional regulation of cell number by mitosis and apoptosis, protein concentration by translation and lysosomal or proteomal degradation, and protein phosphate modification by kinases and phosphatases, biologically regulated memory formation and removal would be yet another example in biological systems where distinct and separate pathways regulate the creation and destruction of biological substrates.

  8. Thermal stress depletes energy reserves in Drosophila.

    PubMed

    Klepsatel, Peter; Gáliková, Martina; Xu, Yanjun; Kühnlein, Ronald P

    2016-09-19

    Understanding how environmental temperature affects metabolic and physiological functions is of crucial importance to assess the impacts of climate change on organisms. Here, we used different laboratory strains and a wild-caught population of the fruit fly Drosophila melanogaster to examine the effect of temperature on the body energy reserves of an ectothermic organism. We found that permanent ambient temperature elevation or transient thermal stress causes significant depletion of body fat stores. Surprisingly, transient thermal stress induces a lasting "memory effect" on body fat storage, which also reduces survivorship of the flies upon food deprivation later after stress exposure. Functional analyses revealed that an intact heat-shock response is essential to protect flies from temperature-dependent body fat decline. Moreover, we found that the temperature-dependent body fat reduction is caused at least in part by apoptosis of fat body cells, which might irreversibly compromise the fat storage capacity of the flies. Altogether, our results provide evidence that thermal stress has a significant negative impact on organismal energy reserves, which in turn might affect individual fitness.

  9. The life cycle of Drosophila orphan genes.

    PubMed

    Palmieri, Nicola; Kosiol, Carolin; Schlötterer, Christian

    2014-02-19

    Orphans are genes restricted to a single phylogenetic lineage and emerge at high rates. While this predicts an accumulation of genes, the gene number has remained remarkably constant through evolution. This paradox has not yet been resolved. Because orphan genes have been mainly analyzed over long evolutionary time scales, orphan loss has remained unexplored. Here we study the patterns of orphan turnover among close relatives in the Drosophila obscura group. We show that orphans are not only emerging at a high rate, but that they are also rapidly lost. Interestingly, recently emerged orphans are more likely to be lost than older ones. Furthermore, highly expressed orphans with a strong male-bias are more likely to be retained. Since both lost and retained orphans show similar evolutionary signatures of functional conservation, we propose that orphan loss is not driven by high rates of sequence evolution, but reflects lineage-specific functional requirements. DOI: http://dx.doi.org/10.7554/eLife.01311.001.

  10. Tools for neuroanatomy and neurogenetics in Drosophila

    SciTech Connect

    Pfeiffer, Barret D.; Jenett, Arnim; Hammonds, Ann S.; Ngo, Teri-T B.; Misra, Sima; Murphy, Christine; Scully, Audra; Carlson, Joseph W.; Wan, Kenneth H.; Laverty, Todd R.; Mungall, Chris; Svirskas, Rob; Kadonaga, James T.; Doe, Chris Q.; Eisen, Michael B.; Celniker, Susan E.; Rubin, Gerald M.

    2008-08-11

    We demonstrate the feasibility of generating thousands of transgenic Drosophila melanogaster lines in which the expression of an exogenous gene is reproducibly directed to distinct small subsets of cells in the adult brain. We expect the expression patterns produced by the collection of 5,000 lines that we are currently generating to encompass all neurons in the brain in a variety of intersecting patterns. Overlapping 3-kb DNA fragments from the flanking noncoding and intronic regions of genes thought to have patterned expression in the adult brain were inserted into a defined genomic location by site-specific recombination. These fragments were then assayed for their ability to function as transcriptional enhancers in conjunction with a synthetic core promoter designed to work with a wide variety of enhancer types. An analysis of 44 fragments from four genes found that >80% drive expression patterns in the brain; the observed patterns were, on average, comprised of <100 cells. Our results suggest that the D. melanogaster genome contains >50,000 enhancers and that multiple enhancers drive distinct subsets of expression of a gene in each tissue and developmental stage. We expect that these lines will be valuable tools for neuroanatomy as well as for the elucidation of neuronal circuits and information flow in the fly brain.

  11. Collective synchronization of divisions in Drosophila development

    NASA Astrophysics Data System (ADS)

    Vergassola, Massimo

    Mitoses in the early development of most metazoans are rapid and synchronized across the entire embryo. While diffusion is too slow, in vitro experiments have shown that waves of the cell-cycle regulator Cdk1 can transfer information rapidly across hundreds of microns. However, the signaling dynamics and the physical properties of chemical waves during embryonic development remain unclear. We develop FRET biosensors for the activity of Cdk1 and the checkpoint kinase Chk1 in Drosophila embryos and exploit them to measure waves in vivo. We demonstrate that Cdk1 chemical waves control mitotic waves and that their speed is regulated by the activity of Cdk1 during the S-phase (and not mitosis). We quantify the progressive slowdown of the waves with developmental cycles and identify its underlying control mechanism by the DNA replication checkpoint through the Chk1/Wee1 pathway. The global dynamics of the mitotic signaling network illustrates a novel control principle: the S-phase activity of Cdk1 regulates the speed of the mitotic wave, while the Cdk1 positive feedback ensures an invariantly rapid onset of mitosis. Mathematical modeling captures the speed of the waves and predicts a fundamental distinction between the S-phase Cdk1 trigger waves and the mitotic phase waves, which is illustrated by embryonic ablation experiments. In collaboration with Victoria Deneke1, Anna Melbinger2, and Stefano Di Talia1 1 Department of Cell Biology, Duke University Medical Center 2 Department of Physics, University of California San Diego.

  12. Live Imaging of Drosophila Larval Neuroblasts

    PubMed Central

    Lerit, Dorothy A.; Plevock, Karen M.; Rusan, Nasser M.

    2014-01-01

    Stem cells divide asymmetrically to generate two progeny cells with unequal fate potential: a self-renewing stem cell and a differentiating cell. Given their relevance to development and disease, understanding the mechanisms that govern asymmetric stem cell division has been a robust area of study. Because they are genetically tractable and undergo successive rounds of cell division about once every hour, the stem cells of the Drosophila central nervous system, or neuroblasts, are indispensable models for the study of stem cell division. About 100 neural stem cells are located near the surface of each of the two larval brain lobes, making this model system particularly useful for live imaging microscopy studies. In this work, we review several approaches widely used to visualize stem cell divisions, and we address the relative advantages and disadvantages of those techniques that employ dissociated versus intact brain tissues. We also detail our simplified protocol used to explant whole brains from third instar larvae for live cell imaging and fixed analysis applications. PMID:25046336

  13. Neuronal control of locomotor handedness in Drosophila.

    PubMed

    Buchanan, Sean M; Kain, Jamey S; de Bivort, Benjamin L

    2015-05-26

    Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are nonheritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality.

  14. Farnesol-Detecting Olfactory Neurons in Drosophila

    PubMed Central

    Ronderos, David S.; Lin, Chun-Chieh; Potter, Christopher J.

    2014-01-01

    We set out to deorphanize a subset of putative Drosophila odorant receptors expressed in trichoid sensilla using a transgenic in vivo misexpression approach. We identified farnesol as a potent and specific activator for the orphan odorant receptor Or83c. Farnesol is an intermediate in juvenile hormone biosynthesis, but is also produced by ripe citrus fruit peels. Here, we show that farnesol stimulates robust activation of Or83c-expressing olfactory neurons, even at high dilutions. The CD36 homolog Snmp1 is required for normal farnesol response kinetics. The neurons expressing Or83c are found in a subset of poorly characterized intermediate sensilla. We show that these neurons mediate attraction behavior to low concentrations of farnesol and that Or83c receptor mutants are defective for this behavior. Or83c neurons innervate the DC3 glomerulus in the antennal lobe and projection neurons relaying information from this glomerulus to higher brain centers target a region of the lateral horn previously implicated in pheromone perception. Our findings identify a sensitive, narrowly tuned receptor that mediates attraction behavior to farnesol and demonstrates an effective approach to deorphanizing odorant receptors expressed in neurons located in intermediate and trichoid sensilla that may not function in the classical “empty basiconic neuron” system. PMID:24623773

  15. Quantitative neuroanatomy for connectomics in Drosophila

    PubMed Central

    Schneider-Mizell, Casey M; Gerhard, Stephan; Longair, Mark; Kazimiers, Tom; Li, Feng; Zwart, Maarten F; Champion, Andrew; Midgley, Frank M; Fetter, Richard D; Saalfeld, Stephan; Cardona, Albert

    2016-01-01

    Neuronal circuit mapping using electron microscopy demands laborious proofreading or reconciliation of multiple independent reconstructions. Here, we describe new methods to apply quantitative arbor and network context to iteratively proofread and reconstruct circuits and create anatomically enriched wiring diagrams. We measured the morphological underpinnings of connectivity in new and existing reconstructions of Drosophila sensorimotor (larva) and visual (adult) systems. Synaptic inputs were preferentially located on numerous small, microtubule-free 'twigs' which branch off a single microtubule-containing 'backbone'. Omission of individual twigs accounted for 96% of errors. However, the synapses of highly connected neurons were distributed across multiple twigs. Thus, the robustness of a strong connection to detailed twig anatomy was associated with robustness to reconstruction error. By comparing iterative reconstruction to the consensus of multiple reconstructions, we show that our method overcomes the need for redundant effort through the discovery and application of relationships between cellular neuroanatomy and synaptic connectivity. DOI: http://dx.doi.org/10.7554/eLife.12059.001 PMID:26990779

  16. Effects of Spaceflight on Drosophila Neural Development

    NASA Technical Reports Server (NTRS)

    Keshishian, Haig S.

    1997-01-01

    The major goal from the animal side, however, has been achieved, namely to develop Drosophila lines where we can assay individual neuromuscular endings directly without dissection. This was achieved by means of using the GAL4-UAS system, where we have succeeded in establishing stocks of flies where the key neuromuscular connections can be assayed directly in undissected larvae by means of the expression of endogenously fluorescent reporters in the specific motor endings. The green fluorescent protein (GFP) as a reporter allows scoring of neural anatomy en-masse in whole mount using fluorescent microscopy without the need for either dissection or specific labeling. Two stocks have been developed. The first, which we developed first, uses the S65T mutant form, which has a dramatically brighter expression than the native protein. This animal will use GAL4 drivers with expression under the control of the elav gene, and which will ensure expression in all neurons of the embryo and larva. The second transgenic animal we have developed is of a novel kind, and makes use of dicistronic design, so that two copies of the protein will be expressed per insert. We have also developed a tricistronic form, but this has not yet been transformed into flies, and we do not imagine that this third line will be ready in time for the flight.

  17. Modulation of Drosophila male behavioral choice

    PubMed Central

    Certel, Sarah J.; Savella, Mary Grace; Schlegel, Dana C. F.; Kravitz, Edward A.

    2007-01-01

    The reproductive and defensive behaviors that are initiated in response to specific sensory cues can provide insight into how choices are made between different social behaviors. We manipulated both the activity and sex of a subset of neurons and found significant changes in male social behavior. Results from aggression assays indicate that the neuromodulator octopamine (OCT) is necessary for Drosophila males to coordinate sensory cue information presented by a second male and respond with the appropriate behavior: aggression rather than courtship. In competitive male courtship assays, males with no OCT or with low OCT levels do not adapt to changing sensory cues and court both males and females. We identified a small subset of neurons in the suboesophageal ganglion region of the adult male brain that coexpress OCT and male forms of the neural sex determination factor, Fruitless (FruM). A single FruM-positive OCT neuron sends extensive bilateral arborizations to the suboesophageal ganglion, the lateral accessory lobe, and possibly the posterior antennal lobe, suggesting a mechanism for integrating multiple sensory modalities. Furthermore, eliminating the expression of FruM by transformer expression in OCT/tyramine neurons changes the aggression versus courtship response behavior. These results provide insight into how complex social behaviors are coordinated in the nervous system and suggest a role for neuromodulators in the functioning of male-specific circuitry relating to behavioral choice. PMID:17360588

  18. Flavonoids and oxidative stress in Drosophila melanogaster.

    PubMed

    Sotibrán, América Nitxin Castañeda; Ordaz-Téllez, María Guadalupe; Rodríguez-Arnaiz, Rosario

    2011-11-27

    Flavonoids are a family of antioxidants that are widely represented in fruits, vegetables, dry legumes, and chocolate, as well as in popular beverages, such as red wine, coffee, and tea. The flavonoids chlorogenic acid, kaempferol, quercetin and quercetin 3β-d-glycoside were investigated for genotoxicity using the wing somatic mutation and recombination test (SMART). This test makes use of two recessive wing cell markers: multiple wing hairs (mwh) and flare (flr(3)), which are mutations located on the left arm of chromosome 3 of Drosophila melanogaster and are indicative of both mitotic recombination and various types of mutational events. In order to test the antioxidant capacities of the flavonoids, experiments were conducted with various combinations of oxidants and polyphenols. Oxidative stress was induced using hydrogen peroxide, the Fenton reaction and paraquat. Third-instar transheterozygous larvae were chronically treated for all experiments. The data obtained in this study showed that, at the concentrations tested, the flavonoids did not induce somatic mutations or recombination in D. melanogaster with the exception of quercetin, which proved to be genotoxic at only one concentration. The oxidants hydrogen peroxide and the Fenton reaction did not induce mutations in the wing somatic assay of D. melanogaster, while paraquat and combinations of flavonoids produced significant numbers of small single spots. Quercetin 3β-d-glycoside mixed with paraquat was shown to be desmutagenic. Combinations of the oxidants with the other flavonoids did not show any antioxidant activity.

  19. Meiotic sex chromosome inactivation in Drosophila.

    PubMed

    Vibranovski, Maria D

    2014-01-01

    In several different taxa, there is indubitable evidence of transcriptional silencing of the X and Y chromosomes in male meiotic cells of spermatogenesis. However, the so called meiotic sex chromosome inactivation (MSCI) has been recently a hot bed for debate in Drosophila melanogaster. This review covers cytological and genetic observations, data from transgenic constructs with testis-specific promoters, global expression profiles obtained from mutant, wild-type, larvae and adult testes as well as from cells of different stages of spermatogenesis. There is no dispute on that D. melanogaster spermatogenesis presents a down-regulation of X chromosome that does not result from the lack of dosage compensation. However, the issue is currently focused on the level of reduction of X-linked expression, the precise time it occurs and how many genes are affected. The deep examination of data and experiments in this review exposes the limitations intrinsic to the methods of studying MSCI in D. melanogaster. The current methods do not allow us to affirm anything else than the X chromosome down-regulation in meiosis (MSCI). Therefore, conclusion about level, degree or precise timing is inadequate until new approaches are implemented to know the details of MSCI or other processes involved for D. melanogaster model.

  20. Structure of full-length Drosophila cryptochrome

    SciTech Connect

    Zoltowski, Brian D.; Vaidya, Anand T.; Top, Deniz; Widom, Joanne; Young, Michael W.; Crane, Brian R.

    2011-12-15

    The cryptochrome/photolyase (CRY/PL) family of photoreceptors mediates adaptive responses to ultraviolet and blue light exposure in all kingdoms of life. Whereas PLs function predominantly in DNA repair of cyclobutane pyrimidine dimers (CPDs) and 6-4 photolesions caused by ultraviolet radiation, CRYs transduce signals important for growth, development, magnetosensitivity and circadian clocks. Despite these diverse functions, PLs/CRYs preserve a common structural fold, a dependence on flavin adenine dinucleotide (FAD) and an internal photoactivation mechanism. However, members of the CRY/PL family differ in the substrates recognized (protein or DNA), photochemical reactions catalysed and involvement of an antenna cofactor. It is largely unknown how the animal CRYs that regulate circadian rhythms act on their substrates. CRYs contain a variable carboxy-terminal tail that appends the conserved PL homology domain (PHD) and is important for function. Here, we report a 2.3-{angstrom} resolution crystal structure of Drosophila CRY with an intact C terminus. The C-terminal helix docks in the analogous groove that binds DNA substrates in PLs. Conserved Trp536 juts into the CRY catalytic centre to mimic PL recognition of DNA photolesions. The FAD anionic semiquinone found in the crystals assumes a conformation to facilitate restructuring of the tail helix. These results help reconcile the diverse functions of the CRY/PL family by demonstrating how conserved protein architecture and photochemistry can be elaborated into a range of light-driven functions.

  1. Mechanotransduction and auditory transduction in Drosophila.

    PubMed

    Kernan, Maurice J

    2007-08-01

    Insects are utterly reliant on sensory mechanotransduction, the process of converting physical stimuli into neuronal receptor potentials. The senses of proprioception, touch, and hearing are involved in almost every aspect of an adult insect's complex behavioral repertoire and are mediated by a diverse array of specialized sensilla and sensory neurons. The physiology and morphology of several of these have been described in detail; genetic approaches in Drosophila, combining behavioral screens and sensory electrophysiology with forward and reverse genetic techniques, have now revealed specific proteins involved in their differentiation and operation. These include three different TRP superfamily ion channels that are required for transduction in tactile bristles, chordotonal stretch receptors, and polymodal nociceptors. Transduction also depends on the normal differentiation and mechanical integrity of the modified cilia that form the neuronal sensory endings, the accessory structures that transmit stimuli to them and, in bristles, a specialized receptor lymph and transepithelial potential. Flies hear near-field sounds with a vibration-sensitive, antennal chordotonal organ. Biomechanical analyses of wild-type antennae reveal non-linear, active mechanical properties that increase their sensitivity to weak stimuli. The effects of mechanosensory and ciliary mutations on antennal mechanics show that the sensory cilia are the active motor elements and indicate distinct roles for TRPN and TRPV channels in auditory transduction and amplification.

  2. Exploring strategies for protein trapping in Drosophila

    SciTech Connect

    Quinones-Coello, Ana T.; Petrella, Lisa N.; Ayers, Kathleen; Melillo, Anthony; Mazzalupo, Stacy; Hudson, Andrew M.; Wang, Shu; Castiblanco, Claudia; Buszczak, Michael; Hoskins, Roger A.; Cooley, Lynn

    2006-12-18

    The use of fluorescent protein tags has had a huge impact oncell biological studies in virtually every experimental system.Incorporation of coding sequence for fluorescent proteins such as greenfluorescent protein (GFP) into genes at their endogenous chromosomalposition is especially useful for generating GFP-fusion proteins thatprovide accurate cellular and subcellular expression data. We testedmodifications of a transposon-based protein trap screening procedure inDrosophila to optimize the rate of recovering useful protein traps andtheir analysis. Transposons carrying the GFP-coding sequence flanked bysplice acceptor and donor sequences were mobilized, and new insertionsthat resulted in production of GFP were captured using an automatedembryo sorter. Individual stocks were established, GFP expression wasanalyzed during oogenesis, and insertion sites were determined bysequencing genomic DNA flanking the insertions. The resulting collectionincludes lines with protein traps in which GFP was spliced into mRNAs andembedded within endogenous proteins or enhancer traps in which GFPexpression depended on splicing into transposon-derived RNA. We report atotal of 335 genes associated with protein or enhancer traps and aweb-accessible database for viewing molecular information and expressiondata for these genes.

  3. Host Plant Adaptation in Drosophila mettleri Populations

    PubMed Central

    Castrezana, Sergio; Bono, Jeremy M.

    2012-01-01

    The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total). We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea) for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp.) in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts. PMID:22493678

  4. Patterns of connectivity in a Drosophila nerve.

    PubMed

    Egger, M D; Nowakowski, R S; Peng, B; Wyman, R J

    1997-10-13

    We investigated the spatial patterns of synaptic profiles in en passant synapses between the premotor axon of a peripherally synapsing interneuron (PAPSI) and a set of individually identifiable motoneuron axons in Drosophila melanogaster. These synaptic profiles are distributed as the axons travel parallel to each other in a bundle; the synapses begin as the axons leave the thoracic ganglion and continue peripherally for 45-65 microm. We found that the number of synaptic profiles per micron length of the motoneuron axons was greatest close to the ganglion; the cumulative distribution of profiles could be fitted to curves of the form f(x) = alpha(1 - e(-beta x)), where x = the distance from the thoracic ganglion, and alpha and beta are constants. The distribution of synaptic profiles was also examined in a mutant strain, Passover (Pas), known to affect connectivity in a pathway that includes the PAPSI. The synaptic profiles between the PAPSI and the motoneuron axons appeared ultrastructurally unremarkable in Pas. Also, the total number of synaptic profiles between the PAPSI and the motoneuron axons did not differ between Pas and wild type flies. However, the distribution of synaptic profiles among the individual motoneuron axons did differ significantly from wild type flies, as did the area of contiguity between the motoneuron axons and the PAPSI, which was much greater in Pas than in wild type flies.

  5. Accelerated food source location in aging Drosophila.

    PubMed

    Egenriether, Sada M; Chow, Eileen S; Krauth, Nathalie; Giebultowicz, Jadwiga M

    2015-10-01

    Adequate energy stores are essential for survival, and sophisticated neuroendocrine mechanisms evolved to stimulate foraging in response to nutrient deprivation. Food search behavior is usually investigated in young animals, and it is not known how aging alters this behavior. To address this question in Drosophila melanogaster, we compared the ability to locate food by olfaction in young and old flies using a food-filled trap. As aging is associated with a decline in motor functions, learning, and memory, we expected that aged flies would take longer to enter the food trap than their young counterparts. Surprisingly, old flies located food with significantly shorter latency than young ones. Robust food search behavior was associated with significantly lower fat reserves and lower starvation resistance in old flies. Food-finding latency (FFL) was shortened in young wild-type flies that were starved until their fat was depleted but also in heterozygous chico mutants with reduced insulin receptor activity and higher fat deposits. Conversely, food trap entry was delayed in old flies with increased insulin signaling. Our results suggest that the difference in FFL between young and old flies is linked to age-dependent differences in metabolic status and may be mediated by reduced insulin signaling.

  6. Functional neuroanatomy of Drosophila olfactory memory formation

    PubMed Central

    Guven-Ozkan, Tugba

    2014-01-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying Drosophila learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive and aversive reinforcers: (1) Which neurons within the olfactory nervous system mediate the acquisition of memory? (2) What is the complete neural circuitry extending from the site(s) of acquisition to the site(s) controlling memory expression? (3) How is information processed across this circuit to consolidate early-forming, disruptable memories to stable, late memories? Much progress has been made and a few strong conclusions have emerged: (1) Acquisition occurs at multiple sites within the olfactory nervous system but is mediated predominantly by the γ mushroom body neurons. (2) The expression of long-term memory is completely dependent on the synaptic output of α/β mushroom body neurons. (3) Consolidation occurs, in part, through circuit interactions between mushroom body and dorsal paired medial neurons. Despite this progress, a complete and unified model that details the pathway from acquisition to memory expression remains elusive. PMID:25225297

  7. Lutein extends the lifespan of Drosophila melanogaster.

    PubMed

    Zhang, Zesheng; Han, Shunkai; Wang, Hao; Wang, Tingting

    2014-01-01

    Lutein is one of the major carotenoids in most fruits and vegetables. The effect of lutein on the lifespan of Drosophila melanogaster was investigated. Results revealed that 0.1mg lutein/ml diet could prolong their mean lifespan from 49.0 to 54.6 days. This was consistent with a significant reduction in malonyldialdehyde (MDA) level and increase in antioxidant enzyme activities of the flies fed with lutein-treated diet compared with those fed with basal diet. Paraquat (PQ) and H2O2 treatment tests demonstrated that lutein could prolong the survival time of the flies. Real-time polymerase chain reaction (RT-PCR) analysis indicated the gene expression of superoxide dismutase (SOD; SOD1 and SOD2), and catalase (CAT) in the lutein-treated group was up-regulated relative to that of the control group. It was concluded that the lifespan-prolonging activity of lutein was partially by up-regulation of endogenous antioxidant enzymes.

  8. Meiotic Sex Chromosome Inactivation in Drosophila

    PubMed Central

    Vibranovski, Maria D.

    2014-01-01

    In several different taxa, there is indubitable evidence of transcriptional silencing of the X and Y chromosomes in male meiotic cells of spermatogenesis. However, the so called meiotic sex chromosome inactivation (MSCI) has been recently a hot bed for debate in Drosophila melanogaster. This review covers cytological and genetic observations, data from transgenic constructs with testis-specific promoters, global expression profiles obtained from mutant, wild-type, larvae and adult testes as well as from cells of different stages of spermatogenesis. There is no dispute on that D. melanogaster spermatogenesis presents a down-regulation of X chromosome that does not result from the lack of dosage compensation. However, the issue is currently focused on the level of reduction of X-linked expression, the precise time it occurs and how many genes are affected. The deep examination of data and experiments in this review exposes the limitations intrinsic to the methods of studying MSCI in D. melanogaster. The current methods do not allow us to affirm anything else than the X chromosome down-regulation in meiosis (MSCI). Therefore, conclusion about level, degree or precise timing is inadequate until new approaches are implemented to know the details of MSCI or other processes involved for D. melanogaster model. PMID:25057326

  9. Neuronal control of locomotor handedness in Drosophila

    PubMed Central

    Buchanan, Sean M.; Kain, Jamey S.; de Bivort, Benjamin L.

    2015-01-01

    Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are nonheritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality. PMID:25953337

  10. Ferritin Assembly in Enterocytes of Drosophila melanogaster

    PubMed Central

    Rosas-Arellano, Abraham; Vásquez-Procopio, Johana; Gambis, Alexis; Blowes, Liisa M.; Steller, Hermann; Mollereau, Bertrand; Missirlis, Fanis

    2016-01-01

    Ferritins are protein nanocages that accumulate inside their cavity thousands of oxidized iron atoms bound to oxygen and phosphates. Both characteristic types of eukaryotic ferritin subunits are present in secreted ferritins from insects, but here dimers between Ferritin 1 Heavy Chain Homolog (Fer1HCH) and Ferritin 2 Light Chain Homolog (Fer2LCH) are further stabilized by disulfide-bridge in the 24-subunit complex. We addressed ferritin assembly and iron loading in vivo using novel transgenic strains of Drosophila melanogaster. We concentrated on the intestine, where the ferritin induction process can be controlled experimentally by dietary iron manipulation. We showed that the expression pattern of Fer2LCH-Gal4 lines recapitulated iron-dependent endogenous expression of the ferritin subunits and used these lines to drive expression from UAS-mCherry-Fer2LCH transgenes. We found that the Gal4-mediated induction of mCherry-Fer2LCH subunits was too slow to effectively introduce them into newly formed ferritin complexes. Endogenous Fer2LCH and Fer1HCH assembled and stored excess dietary iron, instead. In contrast, when flies were genetically manipulated to co-express Fer2LCH and mCherry-Fer2LCH simultaneously, both subunits were incorporated with Fer1HCH in iron-loaded ferritin complexes. Our study provides fresh evidence that, in insects, ferritin assembly and iron loading in vivo are tightly regulated. PMID:26861293

  11. Characterization of mitochondrial ferritin in Drosophila

    PubMed Central

    Missirlis, Fanis; Holmberg, Sara; Georgieva, Teodora; Dunkov, Boris C.; Rouault, Tracey A.; Law, John H.

    2006-01-01

    Mitochondrial function depends on iron-containing enzymes and proteins, whose maturation requires available iron for biosynthesis of iron–sulfur clusters and heme. Little is known about how mitochondrial iron homeostasis is maintained, although the recent discovery of a mitochondrial ferritin in mammals and plants has uncovered a potential key player in the process. Here, we show that Drosophila melanogaster expresses mitochondrial ferritin from an intron-containing gene. It has high similarity to the mouse and human mitochondrial ferritin sequences and, as in mammals, is expressed mainly in testis. This ferritin contains a putative mitochondrial targeting sequence and an epitope-tagged version localizes to mitochondria in transfected cells. Overexpression of mitochondrial ferritin fails to alter both total-body iron levels and iron that is bound to secretory ferritins. However, the viability of iron-deficient flies is compromised by overexpression of mitochondrial ferritin, suggesting that it may sequester iron at the expense of other important cellular functions. The conservation of mitochondrial ferritin in an insect species underscores the importance of this iron-storage molecule. PMID:16571656

  12. Transcriptional responses in a Drosophila defensive symbiosis.

    PubMed

    Hamilton, Phineas T; Leong, Jong S; Koop, Ben F; Perlman, Steve J

    2014-03-01

    Inherited symbionts are ubiquitous in insects and can have important consequences for the fitness of their hosts. Many inherited symbionts defend their hosts against parasites or other natural enemies; however, the means by which most symbionts confer protection is virtually unknown. We examine the mechanisms of defence in a recently discovered case of symbiont-mediated protection, where the bacterial symbiont Spiroplasma defends the fly Drosophila neotestacea from a virulent nematode parasite, Howardula aoronymphium. Using quantitative PCR of Spiroplasma infection intensities and whole transcriptome sequencing, we attempt to distinguish between the following modes of defence: symbiont-parasite competition, host immune priming and the production of toxic factors by Spiroplasma. Our findings do not support a model of exploitative competition between Howardula and Spiroplasma to mediate defence, nor do we find strong support for host immune priming during Spiroplasma infection. Interestingly, we recovered sequence for putative toxins encoded by Spiroplasma, including a novel putative ribosome-inactivating protein, transcripts of which are up-regulated in response to nematode exposure. Protection via the production of toxins may be a widely used and important mechanism in heritable defensive symbioses in insects.

  13. Infection Dynamics and Immune Response in a Newly Described Drosophila-Trypanosomatid Association

    PubMed Central

    Votýpka, Jan; Dostálová, Anna; Yurchenko, Vyacheslav; Bird, Nathan H.; Lukeš, Julius; Lemaitre, Bruno

    2015-01-01

    ABSTRACT Trypanosomatid parasites are significant causes of human disease and are ubiquitous in insects. Despite the importance of Drosophila melanogaster as a model of infection and immunity and a long awareness that trypanosomatid infection is common in the genus, no trypanosomatid parasites naturally infecting Drosophila have been characterized. Here, we establish a new model of trypanosomatid infection in Drosophila—Jaenimonas drosophilae, gen. et sp. nov. As far as we are aware, this is the first Drosophila-parasitic trypanosomatid to be cultured and characterized. Through experimental infections, we find that Drosophila falleni, the natural host, is highly susceptible to infection, leading to a substantial decrease in host fecundity. J. drosophilae has a broad host range, readily infecting a number of Drosophila species, including D. melanogaster, with oral infection of D. melanogaster larvae resulting in the induction of numerous immune genes. When injected into adult hemolymph, J. drosophilae kills D. melanogaster, although interestingly, neither the Imd nor the Toll pathway is induced and Imd mutants do not show increased susceptibility to infection. In contrast, mutants deficient in drosocrystallin, a major component of the peritrophic matrix, are more severely infected during oral infection, suggesting that the peritrophic matrix plays an important role in mediating trypanosomatid infection in Drosophila. This work demonstrates that the J. drosophilae-Drosophila system can be a powerful model to uncover the effects of trypanosomatids in their insect hosts. PMID:26374124

  14. Estimating Divergence Dates and Substitution Rates in the Drosophila Phylogeny

    PubMed Central

    Obbard, Darren J.; Maclennan, John; Kim, Kang-Wook; Rambaut, Andrew; O’Grady, Patrick M.; Jiggins, Francis M.

    2012-01-01

    An absolute timescale for evolution is essential if we are to associate evolutionary phenomena, such as adaptation or speciation, with potential causes, such as geological activity or climatic change. Timescales in most phylogenetic studies use geologically dated fossils or phylogeographic events as calibration points, but more recently, it has also become possible to use experimentally derived estimates of the mutation rate as a proxy for substitution rates. The large radiation of drosophilid taxa endemic to the Hawaiian islands has provided multiple calibration points for the Drosophila phylogeny, thanks to the "conveyor belt" process by which this archipelago forms and is colonized by species. However, published date estimates for key nodes in the Drosophila phylogeny vary widely, and many are based on simplistic models of colonization and coalescence or on estimates of island age that are not current. In this study, we use new sequence data from seven species of Hawaiian Drosophila to examine a range of explicit coalescent models and estimate substitution rates. We use these rates, along with a published experimentally determined mutation rate, to date key events in drosophilid evolution. Surprisingly, our estimate for the date for the most recent common ancestor of the genus Drosophila based on mutation rate (25–40 Ma) is closer to being compatible with independent fossil-derived dates (20–50 Ma) than are most of the Hawaiian-calibration models and also has smaller uncertainty. We find that Hawaiian-calibrated dates are extremely sensitive to model choice and give rise to point estimates that range between 26 and 192 Ma, depending on the details of the model. Potential problems with the Hawaiian calibration may arise from systematic variation in the molecular clock due to the long generation time of Hawaiian Drosophila compared with other Drosophila and/or uncertainty in linking island formation dates with colonization dates. As either source of error will

  15. Lipid droplet-based storage fat metabolism in Drosophila

    PubMed Central

    Kühnlein, Ronald P.

    2012-01-01

    The fruit fly Drosophila melanogaster is an emerging model system in lipid metabolism research. Lipid droplets are omnipresent and dynamically regulated organelles found in various cell types throughout the complex life cycle of this insect. The vital importance of lipid droplets as energy resources and storage compartments for lipoanabolic components has recently attracted research attention to the basic enzymatic machinery, which controls the delicate balance between triacylglycerol deposition and mobilization in flies. This review aims to present current insights in experimentally supported and inferred biological functions of lipogenic and lipolytic enzymes as well as regulatory proteins, which control the lipid droplet-based storage fat turnover in Drosophila. PMID:22566574

  16. Male-male interactions and mating kinetics in Drosophila.

    PubMed

    Wallace, B

    1990-05-01

    Male-male interaction (K) has been estimated from data on the attrition rate of virgin females per minute in a study of the mating kinetics in Drosophila. K is expressed as the time males expend on other males relative to that expended while searching for, courting, and copulating with females. The value of K in these studies ranged from 0 (approximately) to .695; it was affected both by strain (sepia or ebony D. melanogaster and wild-type D. simulans) and by size of the mating chamber. Host-parasitoid models of ecologists appear to be appropriate for examining mating kinetics in Drosophila.

  17. Modeling transcriptional networks in Drosophila development at multiple scales.

    PubMed

    Wunderlich, Zeba; DePace, Angela H

    2011-12-01

    Quantitative models of developmental processes can provide insights at multiple scales. Ultimately, models may be particularly informative for key questions about network level behavior during development such as how does the system respond to environmental perturbation, or operate reliably in different genetic backgrounds? The transcriptional networks that pattern the Drosophila embryo have been the subject of numerous quantitative experimental studies coupled to modeling frameworks in recent years. In this review, we describe three studies that consider these networks at different levels of molecular detail and therefore result in different types of insights. We also discuss other developmental transcriptional networks operating in Drosophila, with the goal of highlighting what additional insights they may provide.

  18. Towards a Drosophila model of Hutchinson-Gilford progeria syndrome.

    PubMed

    Beard, Gemma S; Bridger, Joanna M; Kill, Ian R; Tree, David R P

    2008-12-01

    The laminopathy Hutchinson-Gilford progeria syndrome (HGPS) is caused by the mutant lamin A protein progerin and leads to premature aging of affected children. Despite numerous cell biological and biochemical insights into the basis for the cellular abnormalities seen in HGPS, the mechanism linking progerin to the organismal phenotype is not fully understood. To begin to address the mechanism behind HGPS using Drosophila melanogaster, we have ectopically expressed progerin and lamin A. We found that ectopic progerin and lamin A phenocopy several effects of laminopathies in developing and adult Drosophila, but that progerin causes a stronger phenotype than wild-type lamin A.

  19. Gene expression during the life cycle of Drosophila melanogaster.

    PubMed

    Arbeitman, Michelle N; Furlong, Eileen E M; Imam, Farhad; Johnson, Eric; Null, Brian H; Baker, Bruce S; Krasnow, Mark A; Scott, Matthew P; Davis, Ronald W; White, Kevin P

    2002-09-27

    Molecular genetic studies of Drosophila melanogaster have led to profound advances in understanding the regulation of development. Here we report gene expression patterns for nearly one-third of all Drosophila genes during a complete time course of development. Mutations that eliminate eye or germline tissue were used to further analyze tissue-specific gene expression programs. These studies define major characteristics of the transcriptional programs that underlie the life cycle, compare development in males and females, and show that large-scale gene expression data collected from whole animals can be used to identify genes expressed in particular tissues and organs or genes involved in specific biological and biochemical processes.

  20. Gene Expression During the Life Cycle of Drosophila melanogaster

    NASA Astrophysics Data System (ADS)

    Arbeitman, Michelle N.; Furlong, Eileen E. M.; Imam, Farhad; Johnson, Eric; Null, Brian H.; Baker, Bruce S.; Krasnow, Mark A.; Scott, Matthew P.; Davis, Ronald W.; White, Kevin P.

    2002-09-01

    Molecular genetic studies of Drosophila melanogaster have led to profound advances in understanding the regulation of development. Here we report gene expression patterns for nearly one-third of all Drosophila genes during a complete time course of development. Mutations that eliminate eye or germline tissue were used to further analyze tissue-specific gene expression programs. These studies define major characteristics of the transcriptional programs that underlie the life cycle, compare development in males and females, and show that large-scale gene expression data collected from whole animals can be used to identify genes expressed in particular tissues and organs or genes involved in specific biological and biochemical processes.

  1. CRISPR/Cas9 mediated genome engineering in Drosophila.

    PubMed

    Bassett, Andrew; Liu, Ji-Long

    2014-09-01

    Genome engineering has revolutionised genetic analysis in many organisms. Here we describe a simple and efficient technique to generate and detect novel mutations in desired target genes in Drosophila melanogaster. We target double strand breaks to specific sites within the genome by injecting mRNA encoding the Cas9 endonuclease and in vitro transcribed synthetic guide RNA into Drosophila embryos. The small insertion and deletion mutations that result from inefficient non-homologous end joining at this site are detected by high resolution melt analysis of whole flies and individual wings, allowing stable lines to be made within 1 month.

  2. Signalling through the RhoGEF Pebble in Drosophila.

    PubMed

    Gregory, Stephen L; Lorensuhewa, Nirmal; Saint, Robert

    2010-04-01

    Small GTPase pathways of the Ras superfamily are implicated in a wide range of signalling processes in animal cells. Small GTPases control pathways by acting as molecular switches. They are converted from an inactive GDP-bound form to an active GTP-bound form by GTP exchange factors (GEFs). The spatial and temporal regulation of GEFs is a major component of the regulation of small GTPases. Here we review the role of the Drosophila RhoGEF, Pebble (the Drosophila ortholog of mammalian ECT2). We discuss its roles in cytokinesis and cell migration, highlighting the diversity with which Rho family signalling pathways operate in biological systems.

  3. Nutritional regulation of stem and progenitor cells in Drosophila

    PubMed Central

    Shim, Jiwon; Gururaja-Rao, Shubha; Banerjee, Utpal

    2013-01-01

    Stem cells and their progenitors are maintained within a microenvironment, termed the niche, through local cell-cell communication. Systemic signals originating outside the niche also affect stem cell and progenitor behavior. This review summarizes studies that pertain to nutritional effects on stem and progenitor cell maintenance and proliferation in Drosophila. Multiple tissue types are discussed that utilize the insulin-related signaling pathway to convey nutritional information either directly to these progenitors or via other cell types within the niche. The concept of systemic control of these cell types is not limited to Drosophila and may be functional in vertebrate systems, including mammals. PMID:24255094

  4. Immunohistochemical tools and techniques to visualize Notch in Drosophila melanogaster.

    PubMed

    Tognon, Emiliana; Vaccari, Thomas

    2014-01-01

    The ability to accurately visualize proteins in Drosophila tissues is critical for studying their abundance and localization relative to the morphology of cells during tissue development and homeostasis. Here we describe the procedure to visualize Notch localization in whole-mount preparations of several Drosophila organs using confocal microscopy. The use of monoclonal antibodies directed to distinct portions of Notch allows one to follow the fate of the receptor during constitutive and inductive processes. The protocol described here can be used to co-label with antibodies recognizing markers of subcellular compartments in wild-type as well as mutant tissues.

  5. The aerodynamics of hovering flight in Drosophila.

    PubMed

    Fry, Steven N; Sayaman, Rosalyn; Dickinson, Michael H

    2005-06-01

    Using 3D infrared high-speed video, we captured the continuous wing and body kinematics of free-flying fruit flies, Drosophila melanogaster, during hovering and slow forward flight. We then 'replayed' the wing kinematics on a dynamically scaled robotic model to measure the aerodynamic forces produced by the wings. Hovering animals generate a U-shaped wing trajectory, in which large drag forces during a downward plunge at the start of each stroke create peak vertical forces. Quasi-steady mechanisms could account for nearly all of the mean measured force required to hover, although temporal discrepancies between instantaneous measured forces and model predictions indicate that unsteady mechanisms also play a significant role. We analyzed the requirements for hovering from an analysis of the time history of forces and moments in all six degrees of freedom. The wing kinematics necessary to generate sufficient lift are highly constrained by the requirement to balance thrust and pitch torque over the stroke cycle. We also compare the wing motion and aerodynamic forces of free and tethered flies. Tethering causes a strong distortion of the stroke pattern that results in a reduction of translational forces and a prominent nose-down pitch moment. The stereotyped distortion under tethered conditions is most likely due to a disruption of sensory feedback. Finally, we calculated flight power based directly on the measurements of wing motion and aerodynamic forces, which yielded a higher estimate of muscle power during free hovering flight than prior estimates based on time-averaged parameters. This discrepancy is mostly due to a two- to threefold underestimate of the mean profile drag coefficient in prior studies. We also compared our values with the predictions of the same time-averaged models using more accurate kinematic and aerodynamic input parameters based on our high-speed videography measurements. In this case, the time-averaged models tended to overestimate flight

  6. Antioxidants, metabolic rate and aging in Drosophila.

    PubMed

    Miquel, J; Fleming, J; Economos, A C

    1982-09-01

    In line with the (metabolic) rate-of-living theory of aging, previous work from this laboratory showed that the life-prolonging effect of the antioxidant thiazolidine carboxylic acid (TCA) in Drosophila was paralleled by a similar reduction of the oxygen consumption rate of the flies. To assess the generality of this phenomenon, several life-prolonging antioxidants were dietarily administered to the flies (in standard medium with 1% w/v of tocopherol-stripped corn oil) and their effects on metabolic rate and life span were determined. Respiration rate of groups of continuously agitated flies was measured in the Gilson respirometer. The studied antioxidants were as follows: (the numbers in parentheses are consecutively the antioxidant concentration in the medium in % wt/vol.; mean life span in days; and metabolic rate in microliter O2/mg fly per 24 h): vitamin E (0.4; 46.3; 58.5); 2,4-dinitrophenol (0.1; 45.7; 66.2); nordihydroguaiaretic acid (0.5; 45.6; 69.1); thiazolidine carboxylic acid (0.3; 53.1; 55.8); and control with no antioxidant added (0; 40.7; 73.3). All of these antioxidants at the tested concentrations reduced oxygen consumption rate and increased mean life span; there was a significant negative linear correlation (r = -0.87) between mean life span and metabolic rate. These data suggest that some antioxidants may inhibit respiration rate in addition to their protective effect against free radical-induced cellular damage.

  7. Sexual selection in Drosophila silvestris of Hawaii

    PubMed Central

    Spiess, Eliot B.; Carson, Hampton L.

    1981-01-01

    Previous discovery that Drosophila melanogaster females tend to discriminate in mating against phenotypes of earliest courting males prompted a study of the Hawaiian species D. silvestris. Tibial bristle variation in males from opposite coasts of the island of Hawaii functions in courtship, and the possibility that females can distinguish males differing in the tibial trait is explored. Mating tests, designed to give each female and male an alternative choice between two individuals of opposite sex every 30 min, consisted of intrapopulation tests with a strain derived from an eastern (Kilauea) population and interpopulation tests between that strain and one derived from a western (Kahuku) population. Males were given initial combat tests, with “winners” then used in mating (except one test with “loser” males). Matings (52-55%) were classified into categories according to the readiness of the female to mate and sequence of courtship. Low-threshold females (accepting the first male after less than four courtship bouts) occurred at 30-35%. Among intrapopulational tests, females (with higher threshold) accepted first- and second-courting males about equally (25:36, respectively), but for male success in mating, the winning of initial intermale combats and the uniformity of courtship effort tended to be important criteria. Among interpopulation tests, homogamic matings were nearly equal (25% each), but heterogamic matings contrasted in that Kilauea females were reluctant to mate with Kahuku males (14%), while reciprocal matings occurred most frequently (34%). Females favored males second to court, particularly when a Kilauea male (with extra tibial bristles) was the second male. Thus a morphological feature likely to be influential in mating is demonstrated to be so; and sexual selection is operating via male-male combat plus discrimination in favor of particular opposite-sex individuals in this species. PMID:16593021

  8. Genome Engineering: Drosophila melanogaster and beyond

    PubMed Central

    Venken, Koen J.T.; Sarrion-Perdigones, Alejandro; Vandeventer, Paul J.; Abel, Nicholas S.; Christiansen, Audrey E.; Hoffman, Kristi L.

    2015-01-01

    A central challenge to investigating biological phenomena is the development of techniques to modify genomic DNA with nucleotide precision that can be transmitted through the germ line. Recent years have brought a boon in these technologies, now collectively known as genome engineering. Defined genomic manipulations at the nucleotide level enable a variety of reverse engineering paradigms, providing new opportunities to interrogate diverse biological functions. These genetic modifications include controlled removal, insertion, and substitution of genetic fragments, both small and large. Small fragments up to a few kilobases (e.g., single nucleotide mutations, small deletions, or gene tagging at single or multiple gene loci) to large fragments up to megabase resolution can be manipulated at single loci to create deletions, duplications, inversions, or translocations of substantial sections of whole chromosome arms. A specialized substitution of chromosomal portions that presumably are functionally orthologous between different organisms through syntenic replacement, can provide proof of evolutionary conservation between regulatory sequences. Large transgenes containing endogenous or synthetic DNA can be integrated at defined genomic locations, permitting an alternative proof of evolutionary conservation, and sophisticated transgenes can be used to interrogate biological phenomena. Precision engineering can additionally be used to manipulate the genomes of organelles (e.g., mitochondria). Novel genome engineering paradigms are often accelerated in existing, easily genetically tractable model organisms, primarily because these paradigms can be integrated in a rigorous, existing technology foundation. The Drosophila melanogaster fly model is ideal for these types of studies. Due to its small genome size, having just four chromosomes, the vast amount of cutting-edge genetic technologies, and its short life-cycle and inexpensive maintenance requirements, the fly is

  9. Tandem Duplications and the Limits of Natural Selection in Drosophila yakuba and Drosophila simulans.

    PubMed

    Rogers, Rebekah L; Cridland, Julie M; Shao, Ling; Hu, Tina T; Andolfatto, Peter; Thornton, Kevin R

    2015-01-01

    Tandem duplications are an essential source of genetic novelty, and their variation in natural populations is expected to influence adaptive walks. Here, we describe evolutionary impacts of recently-derived, segregating tandem duplications in Drosophila yakuba and Drosophila simulans. We observe an excess of duplicated genes involved in defense against pathogens, insecticide resistance, chorion development, cuticular peptides, and lipases or endopeptidases associated with the accessory glands across both species. The observed agreement is greater than expectations on chance alone, suggesting large amounts of convergence across functional categories. We document evidence of widespread selection on the D. simulans X, suggesting adaptation through duplication is common on the X. Despite the evidence for positive selection, duplicates display an excess of low frequency variants consistent with largely detrimental impacts, limiting the variation that can effectively facilitate adaptation. Standing variation for tandem duplications spans less than 25% of the genome in D. yakuba and D. simulans, indicating that evolution will be strictly limited by mutation, even in organisms with large population sizes. Effective whole gene duplication rates are low at 1.17 × 10-9 per gene per generation in D. yakuba and 6.03 × 10-10 per gene per generation in D. simulans, suggesting long wait times for new mutations on the order of thousands of years for the establishment of sweeps. Hence, in cases where adaptation depends on individual tandem duplications, evolution will be severely limited by mutation. We observe low levels of parallel recruitment of the same duplicated gene in different species, suggesting that the span of standing variation will define evolutionary outcomes in spite of convergence across gene ontologies consistent with rapidly evolving phenotypes.

  10. Thermal Tolerances of the Spotted-Wing Drosophila Drosophila suzukii (Diptera: Drosophilidae).

    PubMed

    Ryan, Geraldine D; Emiljanowicz, Lisa; Wilkinson, Francesca; Kornya, Melanie; Newman, Jonathan A

    2016-04-01

    The spotted-wing drosophila (Drosophila suzukii Matsumura) is an invasive species of Asian origin that is now widely distributed in North America and Europe. Because of the female’s serrated ovipositor, eggs are laid in preharvest fruit, causing large economic losses in cultivated berries and stone fruit. Modeling D. suzukii population dynamics and potential distribution will require information on its thermal tolerance. Large summer populations have been found in regions with severe winter conditions, though little is known about responses to prolonged low-temperature exposure. We used controlled chambers to examine D. suzukii fecundity, development rate, and mortality across a range of temperatures encompassing the upper and lower thresholds (5–35°C). Optimal temperatures (Topt) were found to be 28.2°C for the development of the egg-to-adult stage, and 22.9°C for reproductive output. No adult eclosion occurred below 8.1°C (Tlower) or above 30.9°C (Tupper). We also investigated survival outcomes following prolonged (42-d) low-temperature exposure to a simulated cold winter (−5, −3, −1, 1, 3, and 5°C). Adult survival was dependent on temperature, with a mean LT50 of 4.9°C. There were no effects of sex, mating status, geographic strain, and photoperiod preexposure on overwintering survival. Thirty-eight percent of females that were mated prior, but not after, prolonged low-temperature exposure produced viable offspring, suggesting that this species may undergo sperm storage. This study provides data on the thermal tolerances of D. suzukii, which can be used for models of D. suzukii population dynamics, degree-day, and distribution models.

  11. Tandem Duplications and the Limits of Natural Selection in Drosophila yakuba and Drosophila simulans

    PubMed Central

    Rogers, Rebekah L.; Cridland, Julie M.; Shao, Ling; Hu, Tina T.; Andolfatto, Peter; Thornton, Kevin R.

    2015-01-01

    Tandem duplications are an essential source of genetic novelty, and their variation in natural populations is expected to influence adaptive walks. Here, we describe evolutionary impacts of recently-derived, segregating tandem duplications in Drosophila yakuba and Drosophila simulans. We observe an excess of duplicated genes involved in defense against pathogens, insecticide resistance, chorion development, cuticular peptides, and lipases or endopeptidases associated with the accessory glands across both species. The observed agreement is greater than expectations on chance alone, suggesting large amounts of convergence across functional categories. We document evidence of widespread selection on the D. simulans X, suggesting adaptation through duplication is common on the X. Despite the evidence for positive selection, duplicates display an excess of low frequency variants consistent with largely detrimental impacts, limiting the variation that can effectively facilitate adaptation. Standing variation for tandem duplications spans less than 25% of the genome in D. yakuba and D. simulans, indicating that evolution will be strictly limited by mutation, even in organisms with large population sizes. Effective whole gene duplication rates are low at 1.17 × 10−9 per gene per generation in D. yakuba and 6.03 × 10−10 per gene per generation in D. simulans, suggesting long wait times for new mutations on the order of thousands of years for the establishment of sweeps. Hence, in cases where adaptation depends on individual tandem duplications, evolution will be severely limited by mutation. We observe low levels of parallel recruitment of the same duplicated gene in different species, suggesting that the span of standing variation will define evolutionary outcomes in spite of convergence across gene ontologies consistent with rapidly evolving phenotypes. PMID:26176952

  12. Biogeography of Drosophila (Diptera: Drosophilidae) in East and Southeast Asia

    PubMed Central

    Robert Liu, Fu-Guo; Tsaur, Shun-Chern; Huang, Hsiao-Ting

    2015-01-01

    The causes of high biological diversity in biodiversity hotspots have long been a major subject of study in conservation biology. To investigate this matter, we conducted a phylogeographic study of five Drosophila (Diptera: Drosophilidae) species from East and Southeast Asia: Drosophila albomicans Duda, D. formosana Duda, D. immigrans Sturtevant, D. melanogaster Meigen, and D. simulans Sturtevant. We collected 185 samples from 28 localities in eight countries. From each collected individual, we sequenced the autosomal extra sex comb gene (esc) and seven mitochondrial genes, including nicotinamide adenine dinucleotide hydrate-reductase dehydrogenase subunit 4 (ND4), ND4L, tRNA-His, tRNA-Pro, tRNA-Thr, partial ND5, and partial ND6. Phylogenetic analyses using maximum- likelihood and Bayesian methods revealed interesting population structure and identified the existence of two distinct D. formosana lineages (Southeast Asian and Taiwanese populations). Genetic differentiation among groups of D. immigrans suggests the possibility of endemic speciation in Taiwan. In contrast, D. melanogaster remained one extensively large population throughout East and Southeast Asia, including nearby islets. A molecular clock was used to estimate divergence times, which were compared with past geographical events to infer evolutionary scenarios. Our findings suggest that interglacial periods may have caused population isolation, thus enhancing population differentiation more strongly for some of the Drosophila species. The population structure of each Drosophila species in East and Southeast Asia has been influenced by past geographic events. PMID:26078303

  13. T-Box Genes in Drosophila Mesoderm Development.

    PubMed

    Reim, I; Frasch, M; Schaub, C

    2017-01-01

    In Drosophila there are eight genes encoding transcription factors of the T-box family, which are known to exert a variety of crucial developmental functions during ectodermal patterning processes, neuronal cell specification, mesodermal tissue development, and the development of extraembryonic tissues. In this review, we focus on the prominent roles of Drosophila T-box genes in mesodermal tissues. First, we describe the contributions of brachyenteron (byn) and optomotor-blind-related-gene-1 (org-1) to the development of the visceral mesoderm. Second, we provide an overview on the functions of the three Dorsocross paralogs (Doc1-3) and the two Tbx20-related paralogs (midline and H15) during Drosophila heart development. Third, we portray the roles of org-1 and midline/H15 in the specification of individual body wall and organ-attached muscles, including the function of org-1 in the transdifferentiation of certain heart-attached muscles during metamorphosis. The functional analysis of these evolutionarily conserved T-box genes, along with their interactions with other types of transcription factors and various signaling pathways, has provided key insights into the regulation of Drosophila visceral mesoderm, muscle, and heart development.

  14. Neuromodulation and Strategic Action Choice in Drosophila Aggression.

    PubMed

    Asahina, Kenta

    2017-03-24

    In this review, I discuss current knowledge and outstanding questions on the neuromodulators that influence aggressive behavior of the fruit fly Drosophila melanogaster. I first present evidence that Drosophila exchange information during an agonistic interaction and choose appropriate actions based on this information. I then discuss the influence of several biogenic amines and neuropeptides on aggressive behavior. One striking characteristic of neuromodulation is that it can configure a neural circuit dynamically, enabling one circuit to generate multiple outcomes. I suggest a consensus effect of each neuromodulatory molecule on Drosophila aggression, as well as effects of receptor proteins where relevant data are available. Lastly, I consider neuromodulation in the context of strategic action choices during agonistic interactions. Genetic components of neuromodulatory systems are highly conserved across animals, suggesting that molecular and cellular mechanisms controlling Drosophila aggression can shed light on neural principles governing action choice during social interactions. Expected final online publication date for the Annual Review of Neuroscience Volume 40 is July 8, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  15. Local adaptation for body color in Drosophila americana

    PubMed Central

    Wittkopp, P J; Smith-Winberry, G; Arnold, L L; Thompson, E M; Cooley, A M; Yuan, D C; Song, Q; McAllister, B F

    2011-01-01

    Pigmentation is one of the most variable traits within and between Drosophila species. Much of this diversity appears to be adaptive, with environmental factors often invoked as selective forces. Here, we describe the geographic structure of pigmentation in Drosophila americana and evaluate the hypothesis that it is a locally adapted trait. Body pigmentation was quantified using digital images and spectrometry in up to 10 flies from each of 93 isofemale lines collected from 17 locations across the United States and found to correlate most strongly with longitude. Sequence variation at putatively neutral loci showed no evidence of population structure and was inconsistent with an isolation-by-distance model, suggesting that the pigmentation cline exists despite extensive gene flow throughout the species range, and is most likely the product of natural selection. In all other Drosophila species examined to date, dark pigmentation is associated with arid habitats; however, in D. americana, the darkest flies were collected from the most humid regions. To investigate this relationship further, we examined desiccation resistance attributable to an allele that darkens pigmentation in D. americana. We found no significant effect of pigmentation on desiccation resistance in this experiment, suggesting that pigmentation and desiccation resistance are not unequivocally linked in all Drosophila species. PMID:20606690

  16. Drosophila models of Alzheimer's disease: advances, limits, and perspectives.

    PubMed

    Bouleau, Sylvina; Tricoire, Hervé

    2015-01-01

    Amyloid-β protein precursor (AβPP) and the microtubule-associated protein tau (MAPT) are the two key players involved in Alzheimer's disease (AD) and are associated with amyloid plaques and neurofibrillary tangles respectively, two key hallmarks of the disease. Besides vertebrate models, Drosophila models have been widely used to understand the complex events leading to AD in relation to aging. Drosophila benefits from the low redundancy of the genome which greatly simplifies the analysis of single gene disruption, sophisticated molecular genetic tools, and reduced cost compared to mammals. The aim of this review is to describe the recent advances in modeling AD using fly and to emphasize some limits of these models. Genetic studies in Drosophila have revealed some key aspects of the normal function of Appl and Tau, the fly homologues of AβPP and MAPT that may be disrupted during AD. Drosophila models have also been useful to uncover or validate several pathological pathways or susceptibility genes, and have been readily implemented in drug screening pipelines. We discuss some limitations of the current models that may arise from differences in structure of Appl and Tau compared to their human counterparts or from missing AβPP or MAPT protein interactors in flies. The advent of new genome modification technologies should allow the development of more realistic fly models and to better understand the relationship between AD and aging, taking advantage of the fly's short lifespan.

  17. Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

    PubMed Central

    Baenas, Nieves; Piegholdt, Stefanie; Schloesser, Anke; Moreno, Diego A.; García-Viguera, Cristina; Rimbach, Gerald; Wagner, Anika E.

    2016-01-01

    We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus. PMID:26901196

  18. Chronic jet lag impairs startle-induced locomotion in Drosophila.

    PubMed

    Vaccaro, Alexandra; Birman, Serge; Klarsfeld, André

    2016-12-01

    Endogenous circadian clocks with ~24-h periodicity are found in most organisms from cyanobacteria to humans. Daylight synchronizes these clocks to solar time. In humans, shift-work and jet lag perturb clock synchronization, and such perturbations, when repeated or chronic, are strongly suspected to be detrimental to healthspan. Here we investigated locomotor aging and longevity in Drosophila melanogaster with genetically or environmentally disrupted clocks. We compared two mutations in period (per, a gene essential for circadian rhythmicity in Drosophila), after introducing them in a common reference genetic background: the arrhythmic per(01), and per(T) which displays robust short 16-h rhythms. Compared to the wild type, both per mutants showed reduced longevity and decreased startle-induced locomotion in aging flies, while spontaneous locomotor activity was not impaired. The per(01) phenotypes were generally less severe than those of per(T), suggesting that chronic jet lag is more detrimental to aging than arrhythmicity in Drosophila. Interestingly, the adjustment of environmental light-dark cycles to the endogenous rhythms of the per(T) mutant fully suppressed the acceleration in the age-related decline of startle-induced locomotion, while it accelerated this decline in wild-type flies. Overall, our results show that chronic jet lag accelerates a specific form of locomotor aging in Drosophila, and that this effect can be alleviated by environmental changes that ameliorate circadian rhythm synchronization.

  19. Context and Occasion Setting in "Drosophila" Visual Learning

    ERIC Educational Resources Information Center

    Brembs, Bjorn; Wiener, Jan

    2006-01-01

    In a permanently changing environment, it is by no means an easy task to distinguish potentially important events from negligible ones. Yet, to survive, every animal has to continuously face that challenge. How does the brain accomplish this feat? Building on previous work in "Drosophila melanogaster" visual learning, we have developed an…

  20. An infrared system for monitoring Drosophila motility during microgravity

    NASA Technical Reports Server (NTRS)

    Miller, Mark S.; Fortney, Michael D.; Keller, Tony S.

    2002-01-01

    Presently, the precise mechanisms of the aging process are unknown. Examination and comprehension of the aging process in other species could lead to significant advances in the understanding of human aging. Drosophila melanogaster (fruit fly), commonly used for aging studies, is a widely studied organism in terms of behavior, development, and genetics. Previous microgravity experiments have shown a significant decrease in the life span of young male Drosophila after microgravity exposure. This decrease in lifespan may be related to locomotor activity, a convenient measure of overall physiological performance. This study describes the design and performance of a Drosophila Infrared Motility Monitoring System (DIMMS). The DIMMS uses a unique design of two infrared (IR) beams per fly to measure the locomotor activity of 240 flies. Locomotor activity is measured in terms of number of IR crossings per unit time, instantaneous velocity, and continuous velocity. Ground-based results using the DIMMS equipment agree well with previous values for Drosophila locomotor velocity. DIMMS is an improvement over equipment previously used due to its ability to continuously monitor locomotor activity throughout short-duration microgravity exposure. DIMMS is also lightweight, compact, and power efficient. DIMMS has been flight tested onboard NASA's KC-135 reduced gravity research aircraft and a Nike-Orion sounding rocket.

  1. Biogeography of Drosophila (Diptera: Drosophilidae) in East and Southeast Asia.

    PubMed

    Liu, Fu-Guo Robert; Tsaur, Shun-Chern; Huang, Hsiao-Ting

    2015-01-01

    The causes of high biological diversity in biodiversity hotspots have long been a major subject of study in conservation biology. To investigate this matter, we conducted a phylogeographic study of five Drosophila (Diptera: Drosophilidae) species from East and Southeast Asia: Drosophila albomicans Duda, D. formosana Duda, D. immigrans Sturtevant, D. melanogaster Meigen, and D. simulans Sturtevant. We collected 185 samples from 28 localities in eight countries. From each collected individual, we sequenced the autosomal extra sex comb gene (esc) and seven mitochondrial genes, including nicotinamide adenine dinucleotide hydrate-reductase dehydrogenase subunit 4 (ND4), ND4L, tRNA-His, tRNA-Pro, tRNA-Thr, partial ND5, and partial ND6. Phylogenetic analyses using maximum- likelihood and Bayesian methods revealed interesting population structure and identified the existence of two distinct D. formosana lineages (Southeast Asian and Taiwanese populations). Genetic differentiation among groups of D. immigrans suggests the possibility of endemic speciation in Taiwan. In contrast, D. melanogaster remained one extensively large population throughout East and Southeast Asia, including nearby islets. A molecular clock was used to estimate divergence times, which were compared with past geographical events to infer evolutionary scenarios. Our findings suggest that interglacial periods may have caused population isolation, thus enhancing population differentiation more strongly for some of the Drosophila species. The population structure of each Drosophila species in East and Southeast Asia has been influenced by past geographic events.

  2. Plexins function in epithelial repair in both Drosophila and zebrafish

    PubMed Central

    Yoo, Sa Kan; Pascoe, Heath G.; Pereira, Telmo; Kondo, Shu; Jacinto, Antonio; Zhang, Xuewu; Hariharan, Iswar K.

    2016-01-01

    In most multicellular organisms, homeostasis is contingent upon maintaining epithelial integrity. When unanticipated insults breach epithelial barriers, dormant programmes of tissue repair are immediately activated. However, many of the mechanisms that repair damaged epithelia remain poorly characterized. Here we describe a role for Plexin A (PlexA), a protein with particularly well-characterized roles in axonal pathfinding, in the healing of damaged epithelia in Drosophila. Semaphorins, which are PlexA ligands, also regulate tissue repair. We show that Drosophila PlexA has GAP activity for the Rap1 GTPase, which is known to regulate the stability of adherens junctions. Our observations suggest that the inhibition of Rap1 activity by PlexA in damaged Drosophila epithelia allows epithelial remodelling, thus facilitating wound repair. We also demonstrate a role for Plexin A1, a zebrafish orthologue of Drosophila PlexA, in epithelial repair in zebrafish tail fins. Thus, plexins function in epithelial wound healing in diverse taxa. PMID:27452696

  3. An infrared system for monitoring Drosophila motility during microgravity.

    PubMed

    Miller, Mark S; Fortney, Michael D; Keller, Tony S

    2002-12-01

    Presently, the precise mechanisms of the aging process are unknown. Examination and comprehension of the aging process in other species could lead to significant advances in the understanding of human aging. Drosophila melanogaster (fruit fly), commonly used for aging studies, is a widely studied organism in terms of behavior, development, and genetics. Previous microgravity experiments have shown a significant decrease in the life span of young male Drosophila after microgravity exposure. This decrease in lifespan may be related to locomotor activity, a convenient measure of overall physiological performance. This study describes the design and performance of a Drosophila Infrared Motility Monitoring System (DIMMS). The DIMMS uses a unique design of two infrared (IR) beams per fly to measure the locomotor activity of 240 flies. Locomotor activity is measured in terms of number of IR crossings per unit time, instantaneous velocity, and continuous velocity. Ground-based results using the DIMMS equipment agree well with previous values for Drosophila locomotor velocity. DIMMS is an improvement over equipment previously used due to its ability to continuously monitor locomotor activity throughout short-duration microgravity exposure. DIMMS is also lightweight, compact, and power efficient. DIMMS has been flight tested onboard NASA's KC-135 reduced gravity research aircraft and a Nike-Orion sounding rocket.

  4. Microevolutionary divergence pattern of the segmentation gene hunchback in Drosophila.

    PubMed

    Tautz, D; Nigro, L

    1998-11-01

    To study the microevolutionary processes shaping the evolution of the segmentation gene hunchback (hb) from Drosophila melanogaster, we cloned and sequenced the gene from 12 isofemale lines representing wild-type populations of D. melanogaster, as well as from the closely related species Drosophila sechellia, Drosophila orena, and Drosophila yakuba. We find a relatively low degree of sequence variation in D. melanogaster (theta = 0.0017), which is, however, consistent with its chromosomal location in a region of low recombination. Tests of neutrality do not reject a neutral-evolution model for the whole region. However, pairwise tests with different subregions indicate that there is a relative excess of polymorphic sites in the leader and the intron. Codon usage pattern analysis shows a particularly biased codon usage in the highly conserved regions, which is in line with the hypothesis that selection on translational accuracy is the driving force behind such a bias. A comparison of the expression pattern of hb in different sibling species of D. melanogaster reveals some regulatory changes in D. yakuba, which could be interpreted as changes in the timing of secondary expression domains.

  5. From Embryo to Adult: Hematopoiesis along the Drosophila Life Cycle.

    PubMed

    Ramond, Elodie; Meister, Marie; Lemaitre, Bruno

    2015-05-26

    Studies on Drosophila hematopoiesis have thus far focused on the embryonic and larval origin of hemocytes, the fly blood cells. In this issue of Developmental Cell, Ghosh et al. (2015) identify adult hematopoietic hubs containing progenitors that can differentiate into different blood cell types.

  6. Handling Alters Aggression and "Loser" Effect Formation in "Drosophila Melanogaster"

    ERIC Educational Resources Information Center

    Trannoy, Severine; Chowdhury, Budhaditya; Kravitz, Edward A.

    2015-01-01

    In "Drosophila," prior fighting experience influences the outcome of later contests: losing a fight increases the probability of losing second contests, thereby revealing "loser" effects that involve learning and memory. In these experiments, to generate and quantify the behavioral changes observed as consequences of losing…

  7. Monitoring Drosophila suzukii Matsumura in Oregon, USA sweet cherry orchards.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii rapidly became a significant cherry pest in the western United States after it was observed damaging cherries in 2009 in California. It has caused significant damage to ripening cherries in all major USA cherry production districts leading to increased management costs and reduced...

  8. Characterization and manipulation of fruit susceptibility to Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii (Matsumura) is an economic pest of small fruits and cherries that attacks intact ripening fruits. Host susceptibility is influenced by characteristics such as flesh firmness, penetration force of the skin, total soluble solids (TSS, also known as °Brix) and pH. Improved knowledge ...

  9. Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

    NASA Astrophysics Data System (ADS)

    Li, Ying; Liu, Zengrong

    MicroRNAs (miRNAs) interact with 3‧untranslated region (UTR) elements of target genes to regulate mRNA stability or translation, and play a crucial role in regulating many different biological processes. bantam, a conserved miRNA, is involved in several functions, such as regulating Drosophila growth and circadian rhythm. Recently, it has been discovered that bantam plays a crucial role in the core circadian pacemaker. In this paper, based on experimental observations, a detailed dynamical model of bantam-regulated circadian clock system is developed to show the post-transcriptional behaviors in the modulation of Drosophila circadian rhythm, in which the regulation of bantam is incorporated into a classical model. The dynamical behaviors of the model are consistent with the experimental observations, which shows that bantam is an important regulator of Drosophila circadian rhythm. The sensitivity analysis of parameters demonstrates that with the regulation of bantam the system is more sensitive to perturbations, indicating that bantam regulation makes it easier for the organism to modulate its period against the environmental perturbations. The effectiveness in rescuing locomotor activity rhythms of mutated flies shows that bantam is necessary for strong and sustained rhythms. In addition, the biological mechanisms of bantam regulation are analyzed, which may help us more clearly understand Drosophila circadian rhythm regulated by other miRNAs.

  10. Isolation and partial characterization of the Drosophila alcohol dehydrogenase gene.

    PubMed Central

    Goldberg, D A

    1980-01-01

    The alcohol dehydrogenase (ADH; alcohol: NAD+ oxidoreductase, EC 1.1.1.1) gene (Adh) of Drosophila melanogaster was isolated by utilizing a mutant strain in which the Adh locus is deleted. Adult RNA from wild-type flies was enriched in ADH sequences by gel electrophoresis and then used to prepare labeled cDNA for screening a bacteriophage lambda library of genomic Drosophila DNA. Of the clones that hybridized in the initial screen, one clone was identified that hybridized with labeled cDNA prepared from a wild-type Drosophila strain but did not hybridize with cDNA prepared from an Adh deletion strain. This clone was shown to contain ADH structural gene sequences by three criteria: in situ hybridization, in vitro translation of mRNA selected by hybridization to the cloned DNA, and comparison of the ADH protein sequence with a nucleotide sequence derived from the cloned DNA. Comparison of the restriction site maps from clones of three different wild-type Drosophila strains revealed the presence of a 200-nucleotide sequence in one strain that was absent from the other two strains. The ADH mRNA sequences were located within the cloned DNA by hybridization mapping experiments. Two intervening sequences were identified within Adh by S1 nuclease mapping experiments. Images PMID:6777776

  11. Trap designs for monitoring Drosophila suzukii (Diptera: Drosophilidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drosophila suzukii Matsumura, an invasive pest of small and stone fruits, has been recently detected in 33 states of the U.S.A., and in Canada, Mexico, and Europe. This pest attacks ripening fruit causing economic losses including increased management costs and crop rejection. Ongoing research aim...

  12. Drosophila evaluates and learns the nutritional value of sugars.

    PubMed

    Fujita, Michiko; Tanimura, Teiichi

    2011-05-10

    Living organisms need to search for and ingest nutritional chemicals, and gustation plays a major role in detecting and discriminating between chemicals present in the environment. Using Drosophila as a model organism, we asked whether animals have the ability to evaluate the nutritional value of sugars. In flies, chemosensilla on the tarsi and labellum are the gustatory organs used to discriminate between edible and nonedible compounds [1, 2]. We noticed that Drosophila do not assign nutritional values to all sweet chemicals. D-arabinose is sweet to flies, but it provides them with no nutrition. By contrast, the sugar alcohol D-sorbitol is not sensed as sweet, but flies can live on it. We performed behavioral and electrophysiological measurements to confirm these gustatory and feeding responses. We found that Drosophila can learn the nutritional value of nonsweet D-sorbitol when it is associated with an odor cue. The learning process involved the synapsin molecule, suggesting that a neuronal mechanism is involved. We propose that Drosophila uses neural machinery to detect, evaluate, and learn the nutritional value of foods after ingestion.

  13. Fly foie gras: modeling fatty liver in Drosophila.

    PubMed

    Arquier, Nathalie; Léopold, Pierre

    2007-02-01

    Lipids provide an essential source of metabolites and energy in normal development as well as during periods of food deprivation. A recent study in Drosophila (Gutierrez et al., 2007) reveals a novel role in regulating lipid metabolism for specialized cells called oenocytes that present striking functional similarities to mammalian hepatocytes.

  14. P element excision in drosophila melanogaster and related drosophilids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The frequency of P element excision and the structure of the resulting excision products were determined in three drosophilid species, Drosophila melanogaster, D. virilis, and Chymomyza procnemis. A transient P element mobility assay was conducted in the cells of developing insect embryos, but unlik...

  15. Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster.

    PubMed

    Baenas, Nieves; Piegholdt, Stefanie; Schloesser, Anke; Moreno, Diego A; García-Viguera, Cristina; Rimbach, Gerald; Wagner, Anika E

    2016-02-18

    We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus.

  16. Fluctuation-Driven Neural Dynamics Reproduce Drosophila Locomotor Patterns

    PubMed Central

    Cruchet, Steeve; Gustafson, Kyle; Benton, Richard; Floreano, Dario

    2015-01-01

    The neural mechanisms determining the timing of even simple actions, such as when to walk or rest, are largely mysterious. One intriguing, but untested, hypothesis posits a role for ongoing activity fluctuations in neurons of central action selection circuits that drive animal behavior from moment to moment. To examine how fluctuating activity can contribute to action timing, we paired high-resolution measurements of freely walking Drosophila melanogaster with data-driven neural network modeling and dynamical systems analysis. We generated fluctuation-driven network models whose outputs—locomotor bouts—matched those measured from sensory-deprived Drosophila. From these models, we identified those that could also reproduce a second, unrelated dataset: the complex time-course of odor-evoked walking for genetically diverse Drosophila strains. Dynamical models that best reproduced both Drosophila basal and odor-evoked locomotor patterns exhibited specific characteristics. First, ongoing fluctuations were required. In a stochastic resonance-like manner, these fluctuations allowed neural activity to escape stable equilibria and to exceed a threshold for locomotion. Second, odor-induced shifts of equilibria in these models caused a depression in locomotor frequency following olfactory stimulation. Our models predict that activity fluctuations in action selection circuits cause behavioral output to more closely match sensory drive and may therefore enhance navigation in complex sensory environments. Together these data reveal how simple neural dynamics, when coupled with activity fluctuations, can give rise to complex patterns of animal behavior. PMID:26600381

  17. Chromatin domain boundary element search tool for Drosophila

    PubMed Central

    Srinivasan, Arumugam; Mishra, Rakesh K.

    2012-01-01

    Chromatin domain boundary elements prevent inappropriate interaction between distant or closely spaced regulatory elements and restrict enhancers and silencers to correct target promoters. In spite of having such a general role and expected frequent occurrence genome wide, there is no DNA sequence analysis based tool to identify boundary elements. Here, we report chromatin domain Boundary Element Search Tool (cdBEST), to identify boundary elements. cdBEST uses known recognition sequences of boundary interacting proteins and looks for ‘motif clusters’. Using cdBEST, we identified boundary sequences across 12 Drosophila species. Of the 4576 boundary sequences identified in Drosophila melanogaster genome, >170 sequences are repetitive in nature and have sequence homology to transposable elements. Analysis of such sequences across 12 Drosophila genomes showed that the occurrence of repetitive sequences in the context of boundaries is a common feature of drosophilids. We use a variety of genome organization criteria and also experimental test on a subset of the cdBEST boundaries in an enhancer-blocking assay and show that 80% of them indeed function as boundaries in vivo. These observations highlight the role of cdBEST in better understanding of chromatin domain boundaries in Drosophila and setting the stage for comparative analysis of boundaries across closely related species. PMID:22287636

  18. From bench to drug: Human seizure modeling using Drosophila

    PubMed Central

    Song, Juan; Tanouye, Mark A.

    2008-01-01

    Studies of human seizure disorders have revealed that susceptibility to seizures is greatly influenced by genetic factors. In addition to causing epilepsy, genetic factors can suppress seizures and epileptogenesis. Examination of seizure-suppressor genes is challenging in humans. However, such genes are readily identified and analyzed in a Drosophila animal model of epilepsy. In this article, the epilepsy phenotype of Drosophila seizure-sensitive mutants is reviewed. A novel class of genes called seizure-suppressors is described. Mutations defining suppressors revert the “epilepsy” phenotype of neurological mutants. We conclude this review with particular discussion of a seizure-suppressor gene encoding DNA topoisomerase I (top1). Mutations of top1 are especially effective at reverting the seizure-sensitive phenotype of Drosophila epilepsy mutants. In addition, an unexpected class of anti-epileptic drugs has been identified. These are DNA topoisomerase I inhibitors such as camptothecin and its derivatives; several candidates are comparable or perhaps better than traditional anti-epileptic drugs such as valproate at reducing seizures in Drosophila drug-feeding experiments. PMID:18063465

  19. Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila

    PubMed Central

    Silva, Bryon; Molina-Fernández, Claudia; Ugalde, María Beatriz; Tognarelli, Eduardo I.; Angel, Cristian; Campusano, Jorge M.

    2015-01-01

    The most studied form of associative learning in Drosophila consists in pairing an odorant, the conditioned stimulus (CS), with an unconditioned stimulus (US). The timely arrival of the CS and US information to a specific Drosophila brain association region, the mushroom bodies (MB), can induce new olfactory memories. Thus, the MB is considered a coincidence detector. It has been shown that olfactory information is conveyed to the MB through cholinergic inputs that activate acetylcholine (ACh) receptors, while the US is encoded by biogenic amine (BA) systems. In recent years, we have advanced our understanding on the specific neural BA pathways and receptors involved in olfactory learning and memory. However, little information exists on the contribution of cholinergic receptors to this process. Here we evaluate for the first time the proposition that, as in mammals, muscarinic ACh receptors (mAChRs) contribute to memory formation in Drosophila. Our results show that pharmacological and genetic blockade of mAChRs in MB disrupts olfactory aversive memory in larvae. This effect is not explained by an alteration in the ability of animals to respond to odorants or to execute motor programs. These results show that mAChRs in MB contribute to generating olfactory memories in Drosophila. PMID:26380118

  20. Investigating Biological Controls to Suppress Spotted Wing Drosophila Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spotted wing drosophila has become a major cherry pest in California. To develop sustainable management options for this highly mobile pest, we worked with cooperators at Oregon State University and the USDA to discover and import natural enemies of the fly from its native range in South Korea ...

  1. Cubilin and amnionless mediate protein reabsorption in Drosophila nephrocytes.

    PubMed

    Zhang, Fujian; Zhao, Ying; Chao, Yufang; Muir, Katherine; Han, Zhe

    2013-02-01

    The insect nephrocyte and the mammalian glomerular podocyte are similar with regard to filtration, but it remains unclear whether there is an organ or cell type in flies that reabsorbs proteins. Here, we show that the Drosophila nephrocyte has molecular, structural, and functional similarities to the renal proximal tubule cell. We screened for genes required for nephrocyte function and identified two Drosophila genes encoding orthologs of mammalian cubilin and amnionless (AMN), two major receptors for protein reabsorption in the proximal tubule. In Drosophila, expression of dCubilin and dAMN is specific to nephrocytes, where they function as co-receptors for protein uptake. Targeted expression of human AMN in Drosophila nephrocytes was sufficient to rescue defective protein uptake induced by dAMN knockdown, suggesting evolutionary conservation of Cubilin/AMN co-receptors function from flies to humans. Furthermore, we found that Cubilin/AMN-mediated protein reabsorption is required for the maintenance of nephrocyte ultrastructure and fly survival under conditions of toxic stress. In conclusion, the insect nephrocyte combines filtration with protein reabsorption, using evolutionarily conserved genes and subcellular structures, suggesting that it can serve as a simplified model for both podocytes and the renal proximal tubule.

  2. The heat shock response restricts virus infection in Drosophila

    PubMed Central

    Merkling, Sarah H.; Overheul, Gijs J.; van Mierlo, Joël T.; Arends, Daan; Gilissen, Christian; van Rij, Ronald P.

    2015-01-01

    Innate immunity is the first line of defence against pathogens and is essential for survival of the infected host. The fruit fly Drosophila melanogaster is an emerging model to study viral pathogenesis, yet antiviral defence responses remain poorly understood. Here, we describe the heat shock response, a cellular mechanism that prevents proteotoxicity, as a component of the antiviral immune response in Drosophila. Transcriptome analyses of Drosophila S2 cells and adult flies revealed strong induction of the heat shock response upon RNA virus infection. Dynamic induction patterns of heat shock pathway components were characterized in vitro and in vivo following infection with different classes of viruses. The heat shock transcription factor (Hsf), as well as active viral replication, were necessary for the induction of the response. Hsf-deficient adult flies were hypersensitive to virus infection, indicating a role of the heat shock response in antiviral defence. In accordance, transgenic activation of the heat shock response prolonged survival time after infection and enabled long-term control of virus replication to undetectable levels. Together, our results establish the heat shock response as an important constituent of innate antiviral immunity in Drosophila. PMID:26234525

  3. Late replication domains are evolutionary conserved in the Drosophila genome.

    PubMed

    Andreyenkova, Natalya G; Kolesnikova, Tatyana D; Makunin, Igor V; Pokholkova, Galina V; Boldyreva, Lidiya V; Zykova, Tatyana Yu; Zhimulev, Igor F; Belyaeva, Elena S

    2013-01-01

    Drosophila chromosomes are organized into distinct domains differing in their predominant chromatin composition, replication timing and evolutionary conservation. We show on a genome-wide level that genes whose order has remained unaltered across 9 Drosophila species display late replication timing and frequently map to the regions of repressive chromatin. This observation is consistent with the existence of extensive domains of repressive chromatin that replicate extremely late and have conserved gene order in the Drosophila genome. We suggest that such repressive chromatin domains correspond to a handful of regions that complete replication at the very end of S phase. We further demonstrate that the order of genes in these regions is rarely altered in evolution. Substantial proportion of such regions significantly coincide with large synteny blocks. This indicates that there are evolutionary mechanisms maintaining the integrity of these late-replicating chromatin domains. The synteny blocks corresponding to the extremely late-replicating regions in the D. melanogaster genome consistently display two-fold lower gene density across different Drosophila species.

  4. Characterization of genomic regulatory domains conserved across the genus Drosophila.

    PubMed

    Sahagun, Virginia; Ranz, José M

    2012-01-01

    In both vertebrates and insects, the conservation of local gene order among distantly related species (microsynteny) is higher than expected in the presence of highly conserved noncoding elements (HCNEs). Dense clusters of HCNEs, or HCNE peaks, have been proposed to mediate the regulation of sometimes distantly located genes, which are central for the developmental program of the organism. Thus, the regions encompassing HCNE peaks and their targets in different species would form genomic regulatory domains (GRDs), which should presumably enjoy an enhanced stability over evolutionary time. By leveraging genome rearrangement information from nine Drosophila species and using gene functional and phenotypic information, we performed a comprehensive characterization of the organization of microsynteny blocks harboring HCNE peaks and provide a functional portrait of the putative HCNE targets that reside therein. We found that Drosophila HCNE peaks tend to colocalize more often than expected and to be evenly distributed across chromosomal elements. Putative HCNE peak targets are characterized by a tight association with particular promoter motifs, higher incidence of severe mutant phenotypes, and evidence of a more precise regulation of gene expression during important developmental transitions. As for their physical organization, ~65% of these putative targets are separated by a median of two genes from their nearest HCNE peaks. These observations represent the first functional portrait of this euchromatic fraction of the Drosophila genome with distinctive evolutionary dynamics, which will facilitate future experimental studies on the interactions between HCNE peaks and their targets in a genetically tractable system such as Drosophila melanogaster.

  5. Resources for Functional Genomics Studies in Drosophila melanogaster

    PubMed Central

    Mohr, Stephanie E.; Hu, Yanhui; Kim, Kevin; Housden, Benjamin E.; Perrimon, Norbert

    2014-01-01

    Drosophila melanogaster has become a system of choice for functional genomic studies. Many resources, including online databases and software tools, are now available to support design or identification of relevant fly stocks and reagents or analysis and mining of existing functional genomic, transcriptomic, proteomic, etc. datasets. These include large community collections of fly stocks and plasmid clones, “meta” information sites like FlyBase and FlyMine, and an increasing number of more specialized reagents, databases, and online tools. Here, we introduce key resources useful to plan large-scale functional genomics studies in Drosophila and to analyze, integrate, and mine the results of those studies in ways that facilitate identification of highest-confidence results and generation of new hypotheses. We also discuss ways in which existing resources can be used and might be improved and suggest a few areas of future development that would further support large- and small-scale studies in Drosophila and facilitate use of Drosophila information by the research community more generally. PMID:24653003

  6. Bacterial entomopathogens from the Drosophila paulistorum semispecies complex.

    PubMed

    Miller, S G; Campbell, B C; Becnel, J; Ehrman, L

    1995-03-01

    Bacteria which are infectious by inoculation in lepidoptera have been isolated and characterized from semispecies comprising the Drosophila paulistorum complex. These microorganisms are pathogenic toward lepidopteran hosts such as Heliothis virescens when introduced by injection of Drosophila tissue extracts and have been given the trivial name DpLE (D. paulistorum lepidopteran entomopathogen). The DpLE from two of the semispecies, Transitional and Andean, were determined to be related to Proteus vulgaris based upon nucleotide sequence comparisons of 16S rDNA genes. Infectivity and 16S rDNA-based PCR assays showed the bacterium to be localized in a number of drosophilid tissues except adult heads and thoraces. Based upon similar experiments, the DpLE in transinfected Heliothis larvae were found in all tissues assayed prior to the onset of mortality. Stocks of Drosophila which had spontaneously lost DpLE continued to produce sterile sons when crossed with incompatible semispecies' females, confirming that the bacilliform DpLE is not the causative agent of the Drosophila paulistorum intersemispecific hybrid male sterility. Acquisition of the sequences of the 16S rDNA molecules of DpLE from all six semispecies permitted the construction of a phylogenetic tree in which the groupings were found not to be congruent with the phylogenies of their insect hosts.

  7. Enhancing undergraduate teaching and research with a Drosophila virginizing system.

    PubMed

    Venema, Dennis R

    2006-01-01

    Laboratory exercises using Drosophila crosses are an effective pedagogical method to complement traditional lecture and textbook presentations of genetics. Undergraduate thesis research is another common setting for using Drosophila. A significant barrier to using Drosophila for undergraduate teaching or research is the time and skill required to accurately collect virgins for use in controlled crosses. Erroneously collecting males or nonvirgin females contaminates crosses with unintended genotypes and confounds the results. Collecting adequate numbers of virgins requires large amounts of time, even for those skilled in virgin collection. I have adapted an effective method for virgin collection that eliminates these concerns and is straightforward to use in undergraduate settings. Using a heat-shock-induced, conditional lethal transgene specifically in males, male larvae can be eliminated from a culture before adults eclose. Females thus eclose in the absence of males and remain virgin, eliminating the need to laboriously score and segregate freshly eclosed females. This method is reliable, easily adaptable to any desired phenotypic marker, and readily scaleable to provide sufficient virgins for large laboratory classes or undergraduate research projects. In addition, it allows instructors lacking Drosophila expertise to use this organism as a pedagogical tool.

  8. Probing the Drosophila Circadian System with Enhancer Detectors.

    DTIC Science & Technology

    2007-11-02

    melanogaster . Genetics 118:461-470. . . 23.Saä?L. and M! W. Young. 1988. In situ localization,ofthe-.per clock protein during development of...R. Preston, R. W. Phyllis, D. M. Johnson-Schlitz, W. K Benz, and W. R. Engels. 1988. A stable source of P-element transposase in Drosophila

  9. Enhancing Undergraduate Teaching and Research with a Drosophila Virginizing System

    PubMed Central

    2006-01-01

    Laboratory exercises using Drosophila crosses are an effective pedagogical method to complement traditional lecture and textbook presentations of genetics. Undergraduate thesis research is another common setting for using Drosophila. A significant barrier to using Drosophila for undergraduate teaching or research is the time and skill required to accurately collect virgins for use in controlled crosses. Erroneously collecting males or nonvirgin females contaminates crosses with unintended genotypes and confounds the results. Collecting adequate numbers of virgins requires large amounts of time, even for those skilled in virgin collection. I have adapted an effective method for virgin collection that eliminates these concerns and is straightforward to use in undergraduate settings. Using a heat-shock–induced, conditional lethal transgene specifically in males, male larvae can be eliminated from a culture before adults eclose. Females thus eclose in the absence of males and remain virgin, eliminating the need to laboriously score and segregate freshly eclosed females. This method is reliable, easily adaptable to any desired phenotypic marker, and readily scaleable to provide sufficient virgins for large laboratory classes or undergraduate research projects. In addition, it allows instructors lacking Drosophila expertise to use this organism as a pedagogical tool. PMID:17146043

  10. The Drosophila hairpin RNA pathway generates endogenous short interfering RNAs

    PubMed Central

    Okamura, Katsutomo; Chung, Wei-Jen; Ruby, J. Graham; Guo, Huili; Bartel, David P.; Lai, Eric C.

    2009-01-01

    In contrast to microRNAs and Piwi-associated RNAs, short interfering RNAs (siRNAs) are seemingly dispensable for host-directed gene regulation in Drosophila. This notion is based on the fact that mutants lacking the core siRNA-generating enzyme Dicer-2 or the predominant siRNA effector Argonaute 2 are viable, fertile and of relatively normal morphology1,2. Moreover, endogenous Drosophila siRNAs have not yet been identified. Here we report that siRNAs derived from long hairpin RNA genes (hpRNAs) programme Slicer complexes that can repress endogenous target transcripts. The Drosophila hpRNA pathway is a hybrid mechanism that combines canonical RNA interference factors (Dicer-2, Hen1 (known as CG12367) and Argonaute 2) with a canonical microRNA factor (Loquacious) to generate ~21-nucleotide siRNAs. These novel regulatory RNAs reveal unexpected complexity in the sorting of small RNAs, and open a window onto the biological usage of endogenous RNA interference in Drosophila. PMID:18463630

  11. Cellular and developmental adaptations to hypoxia: a Drosophila perspective.

    PubMed

    Romero, Nuria Magdalena; Dekanty, Andrés; Wappner, Pablo

    2007-01-01

    The fruit fly Drosophila melanogaster, a widely utilized genetic model, is highly resistant to oxygen starvation and is beginning to be used for studying physiological, developmental, and cellular adaptations to hypoxia. The Drosophila respiratory (tracheal) system has features in common with the mammalian circulatory system so that an angiogenesis-like response occurs upon exposure of Drosophila larvae to hypoxia. A hypoxia-responsive system homologous to mammalian hypoxia-inducible factor (HIF) has been described in the fruit fly, where Fatiga is a Drosophila oxygen-dependent HIF prolyl hydroxylase, and the basic helix-loop-helix Per/ARNT/Sim (bHLH-PAS) proteins Sima and Tango are, respectively, the Drosophila homologues of mammalian HIF-alpha (alpha) and HIF-beta (beta). Tango is constitutively expressed regardless of oxygen tension and, like in mammalian cells, Sima is controlled at the level of protein degradation and subcellular localization. Sima is critically required for development in hypoxia, but, unlike mammalian model systems, it is dispensable for development in normoxia. In contrast, fatiga mutant alleles are all lethal; however, strikingly, viability to adulthood is restored in fatiga sima double mutants, although these double mutants are not entirely normal, suggesting that Fatiga has Sima-independent functions in fly development. Studies in cell culture and in vivo have revealed that Sima is activated by the insulin receptor (InR) and target-of-rapamycin (TOR) pathways. Paradoxically, Sima is a negative regulator of growth. This suggests that Sima is engaged in a negative feedback loop that limits growth upon stimulation of InR/TOR pathways.

  12. Sucrose Improves Insecticide Activity Against Drosophila suzukii (Diptera: Drosophilidae).

    PubMed

    Cowles, Richard S; Rodriguez-Saona, Cesar; Holdcraft, Robert; Loeb, Gregory M; Elsensohn, Johanna E; Hesler, Steven P

    2015-04-01

    The addition of sucrose to insecticides targeting spotted wing drosophila, Drosophila suzukii (Matsumura), enhanced lethality in laboratory, semifield, and field tests. In the laboratory, 0.1% sucrose added to a spray solution enhanced spotted wing drosophila feeding. Flies died 120 min earlier when exposed to spinosad residues at label rates enhanced with sucrose. Added sucrose reduced the LC50 for dried acetamiprid residues from 82 to 41 ppm in the spray solution. Laboratory bioassays of spotted wing drosophila mortality followed exposure to grape and blueberry foliage and/or fruit sprayed and aged in the field. On grape foliage, the addition of 2.4 g/liter of sugar with insecticide sprays resulted in an 11 and 6% increase of spotted wing drosophila mortality at 1 and 2 d exposures to residues, respectively, averaged over seven insecticides with three concentrations. In a separate experiment, spinetoram and cyantraniliprole reduced by 95-100% the larval infestation of blueberries, relative to the untreated control, 7 d after application at labeled rates when applied with 1.2 g/liter sucrose in a spray mixture, irrespective of rainfall; without sucrose infestation was reduced by 46-91%. Adding sugar to the organically acceptable spinosyn, Entrust, reduced larval infestation of strawberries by >50% relative to without sugar for five of the six sample dates during a season-long field trial. In a small-plot field test with blueberries, weekly applications in alternating sprays of sucrose plus reduced-risk insecticides, spinetoram or acetamiprid, reduced larval infestation relative to the untreated control by 76%; alternating bifenthrin and phosmet (without sucrose) reduced infestation by 65%.

  13. A mathematical model for apoptotic switch in Drosophila

    NASA Astrophysics Data System (ADS)

    Ziraldo, Riccardo; Ma, Lan

    2015-10-01

    Apoptosis is an evolutionarily-conserved process of autonomous cell death. The molecular switch mechanism underlying the fate decision of apoptosis in mammalian cells has been intensively studied by mathematical modeling. In contrast, the apoptotic switch in invertebrates, with highly conserved signaling proteins and pathway, remains poorly understood mechanistically and calls for theoretical elucidation. In this study, we develop a mathematical model of the apoptosis pathway in Drosophila and compare the switch mechanism to that in mammals. Enumeration of the elementary reactions for the model demonstrates that the molecular interactions among the signaling components are considerably different from their mammalian counterparts. A notable distinction in network organization is that the direct positive feedback from the effector caspase (EC) to the initiator caspase in mammalian pathway is replaced by a double-negative regulation in Drosophila. The model is calibrated by experimental input-output relationship and the simulated trajectories exhibit all-or-none bimodal behavior. Bifurcation diagrams confirm that the model of Drosophila apoptotic switch possesses bistability, a well-recognized feature for an apoptosis system. Since the apoptotic protease activating factor-1 (APAF1) induced irreversible activation of caspase is an essential and beneficial property for the mammalian apoptotic switch, we perform analysis of the bistable caspase activation with respect to the input of DARK protein, the Drosophila homolog of APAF1. Interestingly, this bistable behavior in Drosophila is predicted to be reversible. Further analysis suggests that the mechanism underlying the systems property of reversibility is the double-negative feedback from the EC to the initiator caspase. Using theoretical modeling, our study proposes plausible evolution of the switch mechanism for apoptosis between organisms.

  14. Molecular genetic analysis of circadian timekeeping in Drosophila.

    PubMed

    Hardin, Paul E

    2011-01-01

    A genetic screen for mutants that alter circadian rhythms in Drosophila identified the first clock gene-the period (per) gene. The per gene is a central player within a transcriptional feedback loop that represents the core mechanism for keeping circadian time in Drosophila and other animals. The per feedback loop, or core loop, is interlocked with the Clock (Clk) feedback loop, but whether the Clk feedback loop contributes to circadian timekeeping is not known. A series of distinct molecular events are thought to control transcriptional feedback in the core loop. The time it takes to complete these events should take much less than 24h, thus delays must be imposed at different steps within the core loop. As new clock genes are identified, the molecular mechanisms responsible for these delays have been revealed in ever-increasing detail and provide an in-depth accounting of how transcriptional feedback loops keep circadian time. The phase of these feedback loops shifts to maintain synchrony with environmental cycles, the most reliable of which is light. Although a great deal is known about cell-autonomous mechanisms of light-induced phase shifting by CRYPTOCHROME (CRY), much less is known about non-cell autonomous mechanisms. CRY mediates phase shifts through an uncharacterized mechanism in certain brain oscillator neurons and carries out a dual role as a photoreceptor and transcription factor in other tissues. Here, I review how transcriptional feedback loops function to keep time in Drosophila, how they impose delays to maintain a 24-h cycle, and how they maintain synchrony with environmental light:dark cycles. The transcriptional feedback loops that keep time in Drosophila are well conserved in other animals, thus what we learn about these loops in Drosophila should continue to provide insight into the operation of analogous transcriptional feedback loops in other animals.

  15. Combinatorial Gene Regulatory Functions Underlie Ultraconserved Elements in Drosophila.

    PubMed

    Warnefors, Maria; Hartmann, Britta; Thomsen, Stefan; Alonso, Claudio R

    2016-09-01

    Ultraconserved elements (UCEs) are discrete genomic elements conserved across large evolutionary distances. Although UCEs have been linked to multiple facets of mammalian gene regulation their extreme evolutionary conservation remains largely unexplained. Here, we apply a computational approach to investigate this question in Drosophila, exploring the molecular functions of more than 1,500 UCEs shared across the genomes of 12 Drosophila species. Our data indicate that Drosophila UCEs are hubs for gene regulatory functions and suggest that UCE sequence invariance originates from their combinatorial roles in gene control. We also note that the gene regulatory roles of intronic and intergenic UCEs (iUCEs) are distinct from those found in exonic UCEs (eUCEs). In iUCEs, transcription factor (TF) and epigenetic factor binding data strongly support iUCE roles in transcriptional and epigenetic regulation. In contrast, analyses of eUCEs indicate that they are two orders of magnitude more likely than the expected to simultaneously include protein-coding sequence, TF-binding sites, splice sites, and RNA editing sites but have reduced roles in transcriptional or epigenetic regulation. Furthermore, we use a Drosophila cell culture system and transgenic Drosophila embryos to validate the notion of UCE combinatorial regulatory roles using an eUCE within the Hox gene Ultrabithorax and show that its protein-coding region also contains alternative splicing regulatory information. Taken together our experiments indicate that UCEs emerge as a result of combinatorial gene regulatory roles and highlight common features in mammalian and insect UCEs implying that similar processes might underlie ultraconservation in diverse animal taxa.

  16. Combinatorial Gene Regulatory Functions Underlie Ultraconserved Elements in Drosophila

    PubMed Central

    Warnefors, Maria; Hartmann, Britta; Thomsen, Stefan; Alonso, Claudio R.

    2016-01-01

    Ultraconserved elements (UCEs) are discrete genomic elements conserved across large evolutionary distances. Although UCEs have been linked to multiple facets of mammalian gene regulation their extreme evolutionary conservation remains largely unexplained. Here, we apply a computational approach to investigate this question in Drosophila, exploring the molecular functions of more than 1,500 UCEs shared across the genomes of 12 Drosophila species. Our data indicate that Drosophila UCEs are hubs for gene regulatory functions and suggest that UCE sequence invariance originates from their combinatorial roles in gene control. We also note that the gene regulatory roles of intronic and intergenic UCEs (iUCEs) are distinct from those found in exonic UCEs (eUCEs). In iUCEs, transcription factor (TF) and epigenetic factor binding data strongly support iUCE roles in transcriptional and epigenetic regulation. In contrast, analyses of eUCEs indicate that they are two orders of magnitude more likely than the expected to simultaneously include protein-coding sequence, TF-binding sites, splice sites, and RNA editing sites but have reduced roles in transcriptional or epigenetic regulation. Furthermore, we use a Drosophila cell culture system and transgenic Drosophila embryos to validate the notion of UCE combinatorial regulatory roles using an eUCE within the Hox gene Ultrabithorax and show that its protein-coding region also contains alternative splicing regulatory information. Taken together our experiments indicate that UCEs emerge as a result of combinatorial gene regulatory roles and highlight common features in mammalian and insect UCEs implying that similar processes might underlie ultraconservation in diverse animal taxa. PMID:27247329

  17. Erythritol and Lufenuron Detrimentally Alter Age Structure of Wild Spotted Wing Drosophila (SWD) Drosophila suzukii (Diptera: Drosophilidae) Populations in Blueberry and Blackberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report on the efficacy of 0.5 M (61,000 ppm) Erythritol (E) in Truvia Baking Blend®, 10 ppm Lufenuron (L), and their combination (LE) to reduce egg and larval densities of wild populations of spotted wing Drosophila, Drosophila suzukii (Matsumura) (SWD) infesting fields of rabbiteye blueberries (...

  18. Environmental ethanol as an ecological constraint on the dietary breadth of the Spotted-Wing Drosophila, Drosophila suzukii Mat. (Diptera: Drosophilidae) and its implication for integrated pest management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted-wing Drosophila (SWD), Drosophila suzukii, is a recent exotic insect pest of the Americas. What makes SWD particularly destructive is the female’s double bladed and prominently serrated ovipositor, which inserts eggs below the epidermis of intact berries. Unlike the vast majority of Drosophi...

  19. Trapping spotted wing drosophila, Drosophila suzukii (Matsumura)(Diptera: Drosophilidae) with combinations of vinegar and wine, and acetic acid and ethanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recommendations for monitoring spotted wing drosophila (SWD) Drosophila suzukii, (Matsumura) are to use either vinegar or wine as a bait for traps. Traps baited with vinegar and traps baited with wine, in field tests in northern Oregon, captured large numbers of male and female SWD flies. Numbers of...

  20. Seasonal and regional presence of hymenopteran parasitoids of Drosophila in Switzerland and their ability to parasitize the invasive Drosophila suzukii

    PubMed Central

    Knoll, Valery; Ellenbroek, Thomas; Romeis, Jörg; Collatz, Jana

    2017-01-01

    Since its introduction into Europe the invasive Drosophila suzukii has established and spread widely, thereby entering habitats populated by native Drosophila species and their natural enemies. The highly prolific D. suzukii will likely interact with these species as a competitor, host or prey. To investigate potential interactions of D. suzukii with parasitoids, a field survey was conducted across several fruit-growing regions in Switzerland in two consecutive years. Eight species of hymenopteran parasitoids were collected using D. melanogaster as sentinel hosts in field-traps. Parasitoid capture was much higher in 2015 than in 2014 and varied among regions, time of the growing season, and habitat type. Laboratory no-choice assays with the field-collected species demonstrated that the larval parasitoids Asobara tabida, Leptopilina boulardi, and L. heterotoma could not use D. suzukii for reproduction, although the latter two reduced the number of emerging D. suzukii. In contrast, the pupal parasitoids Pachycrepoideus vindemmiae, Trichopria drosophilae, Vrestovia fidenas and Spalangia erythromera all developed with D. suzukii as hosts. Regional differences between strains were generally not evident, with the exception of two T. drosophilae strains that differed in parasitization rate. Thus, native parasitoids may interact with D. suzukii and should be regarded when implementing pest control measures. PMID:28098183

  1. Effect of sterol metabolism in the yeast-Drosophila system on the frequency of radiation-induced aneuploidy in the Drosophila melanogaster oocytes

    SciTech Connect

    Savitskii, V.V.; Luchnikova, E.M.; Inge-Vechtomov, S.G.

    1986-01-01

    The effect of sterol metabolism on induced mutagenesis of Drosophila melanogaster was studied in the ecogenetic system of yeast-Drosophila. Sterol deficiency was created in Drosophila by using the biomass of live cells of Saccharomyces cerevisiae strain 9-2-P712 till mutation in locus nys/sup r1/ blocking the synthesis of ergosterol as the food. It was found that rearing of Drosophila females on the mutant yeast increases the frequency of loss and nondisjunction of X chromosomes induced in mature oocytes by X rays (1000 R). Addition of 0.1% of cholesterol solution in 10% ethanol to the yeast biomass restores the resistance of oocyte to X irradiation to the control level. The possible hormonal effect on membrane leading to increased radiation-induced aneuploidy in Drosophila and the role of sterol metabolism in determining the resistance to various damaging factors are discussed.

  2. System identification of Drosophila olfactory sensory neurons.

    PubMed

    Kim, Anmo J; Lazar, Aurel A; Slutskiy, Yevgeniy B

    2011-02-01

    The lack of a deeper understanding of how olfactory sensory neurons (OSNs) encode odors has hindered the progress in understanding the olfactory signal processing in higher brain centers. Here we employ methods of system identification to investigate the encoding of time-varying odor stimuli and their representation for further processing in the spike domain by Drosophila OSNs. In order to apply system identification techniques, we built a novel low-turbulence odor delivery system that allowed us to deliver airborne stimuli in a precise and reproducible fashion. The system provides a 1% tolerance in stimulus reproducibility and an exact control of odor concentration and concentration gradient on a millisecond time scale. Using this novel setup, we recorded and analyzed the in-vivo response of OSNs to a wide range of time-varying odor waveforms. We report for the first time that across trials the response of OR59b OSNs is very precise and reproducible. Further, we empirically show that the response of an OSN depends not only on the concentration, but also on the rate of change of the odor concentration. Moreover, we demonstrate that a two-dimensional (2D) Encoding Manifold in a concentration-concentration gradient space provides a quantitative description of the neuron's response. We then use the white noise system identification methodology to construct one-dimensional (1D) and two-dimensional (2D) Linear-Nonlinear-Poisson (LNP) cascade models of the sensory neuron for a fixed mean odor concentration and fixed contrast. We show that in terms of predicting the intensity rate of the spike train, the 2D LNP model performs on par with the 1D LNP model, with a root mean-square error (RMSE) increase of about 5 to 10%. Surprisingly, we find that for a fixed contrast of the white noise odor waveforms, the nonlinear block of each of the two models changes with the mean input concentration. The shape of the nonlinearities of both the 1D and the 2D LNP model appears to be

  3. Genome engineering: Drosophila melanogaster and beyond.

    PubMed

    Venken, Koen J T; Sarrion-Perdigones, Alejandro; Vandeventer, Paul J; Abel, Nicholas S; Christiansen, Audrey E; Hoffman, Kristi L

    2016-01-01

    A central challenge in investigating biological phenomena is the development of techniques to modify genomic DNA with nucleotide precision that can be transmitted through the germ line. Recent years have brought a boon in these technologies, now collectively known as genome engineering. Defined genomic manipulations at the nucleotide level enable a variety of reverse engineering paradigms, providing new opportunities to interrogate diverse biological functions. These genetic modifications include controlled removal, insertion, and substitution of genetic fragments, both small and large. Small fragments up to a few kilobases (e.g., single nucleotide mutations, small deletions, or gene tagging at single or multiple gene loci) to large fragments up to megabase resolution can be manipulated at single loci to create deletions, duplications, inversions, or translocations of substantial sections of whole chromosome arms. A specialized substitution of chromosomal portions that presumably are functionally orthologous between different organisms through syntenic replacement, can provide proof of evolutionary conservation between regulatory sequences. Large transgenes containing endogenous or synthetic DNA can be integrated at defined genomic locations, permitting an alternative proof of evolutionary conservation, and sophisticated transgenes can be used to interrogate biological phenomena. Precision engineering can additionally be used to manipulate the genomes of organelles (e.g., mitochondria). Novel genome engineering paradigms are often accelerated in existing, easily genetically tractable model organisms, primarily because these paradigms can be integrated in a rigorous, existing technology foundation. The Drosophila melanogaster fly model is ideal for these types of studies. Due to its small genome size, having just four chromosomes, the vast amount of cutting-edge genetic technologies, and its short life-cycle and inexpensive maintenance requirements, the fly is

  4. Unifying General and Segmented Contracted Basis Sets. Segmented Polarization Consistent Basis Sets.

    PubMed

    Jensen, Frank

    2014-03-11

    We propose a method, denoted P-orthogonalization, for converting a general contracted basis set to a computationally more efficient segmented contracted basis set, while inheriting the full accuracy of the general contracted basis set. The procedure can be used for any general contracted basis set to remove the redundancies between general contracted functions in terms of primitive functions. The P-orthogonalization procedure is used to construct a segmented contracted version of the polarization consistent basis sets, which are optimized for density functional theory calculations. Benchmark calculations show that the new pcs-n basis sets provide uniform error control of the basis set incompleteness for molecular systems composed of atoms from the first three rows in the periodic table (H-Kr) and for different exchange-correlation functionals. The basis set errors at a given zeta quality level are lower than other existing basis sets, and the pcs-n basis sets are furthermore shown to be among the computationally most efficient. The pcs-n basis sets are available in qualities ranging from (unpolarized) double-zeta to pentuple zeta quality and should therefore be well suited for both routine and benchmark calculations using density functional theory methods in general.

  5. Involvement of cytochrome P450 in host-plant utilization by Sonoran Desert Drosophila.

    PubMed Central

    Frank, M R; Fogleman, J C

    1992-01-01

    The four Drosophila species endemic to the Sonoran Desert (Drosophila mettleri, Drosophila mojavensis, Drosophila nigrospiracula, and Drosophila pachea) utilize necrotic cactus tissue or soil soaked by rot exudate as breeding substrates. Each Drosophila species uses a different cactus species as its primary host. D. pachea is limited to senita cactus by a biochemical dependency on unusual sterols available only in that cactus. For the other Drosophila species, no such chemical dependencies exist to explain the relationships with their primary host plants. Each cactus species has a different array of allelochemicals that have detrimental effects on non-resident fly species. We have hypothesized that the desert fly-cactus associations are due, in part, to differences between the fly species in their allelochemical detoxication enzymes, the cytochrome P450 system. To test whether P450s are involved in the detoxication of cactus allelochemicals, several experiments were done. (i) The effect of a specific P450 inhibitor, piperonyl butoxide, on larval survival through eclosion on each cactus substrate was investigated. (ii) In vitro metabolism of cactus alkaloids was determined for each Drosophila species. The effects of specific inducers and inhibitors were included in these experiments. (iii) The basal and induced content of cytochrome P450 in each species was determined. The results support the hypothesis that P450 enzymes are involved in host-plant utilization by these Sonoran Desert Drosophila species. Images PMID:1465429

  6. FlyBase: a Drosophila database. The FlyBase consortium.

    PubMed Central

    Gelbart, W M; Crosby, M; Matthews, B; Rindone, W P; Chillemi, J; Russo Twombly, S; Emmert, D; Ashburner, M; Drysdale, R A; Whitfield, E; Millburn, G H; de Grey, A; Kaufman, T; Matthews, K; Gilbert, D; Strelets, V; Tolstoshev, C

    1997-01-01

    FlyBase is a database of genetic and molecular data concerning Drosophila. FlyBase is maintained as a relational database (in Sybase) and is made available as html documents and flat files. The scope of FlyBase includes: genes, alleles (and phenotypes), aberrations, transposons, pointers to sequence data, clones, stock lists, Drosophila workers and bibliographic references. The Encyclopedia of Drosophila is a joint effort between FlyBase and the Berkeley Drosophila Genome Project which integrates FlyBase data with those from the BDGP. PMID:9045212

  7. Solvent dimethylsulfoxide (DMSO) does not induce aneuploidy in oocytes of Drosophila melanogaster

    SciTech Connect

    Traut, H.

    1983-01-01

    Both with a conventional method and with the ''aneuploidy pattern method'' the authors tested whether the solvent dimethylsulfoxide (DMSO) is able to induce aneuploidy (numerical chromosome aberrations) in oocytes of Drosophila melanogaster. DMSO was fed as a 2% solution to Drosophila females. No evidence for a mutagenic activity was obtained. This finding and the negative results reported by other authors for other types of mutation in Drosophila show that DMSO can be used as a solvent for chemical agents in mutagencity screening in Drosophila melanogaster.

  8. Blood cells of Drosophila: cell lineages and role in host defence.

    PubMed

    Meister, Marie

    2004-02-01

    Drosophila haemopoiesis gives rise to three independent cell lineages: plasmatocytes, crystal cells and lamellocytes. The regulation of Drosophila stem cell proliferation and lineage specification involves transactivators and signalling pathways, many of which have mammalian counterparts that control haemopoietic processes. Drosophila plasmatocytes are professional phagocytes that resemble the monocyte/macrophage lineage, crystal cells play a critical role in defence-related melanisation, and lamellocytes encapsulate large invaders. Crystal cells and lamellocytes have no clear mammalian homologues. Research into the molecular mechanisms that underlie the various immune functions of Drosophila blood cells, such as non-self recognition, is now taking wing.

  9. Basal tolerance to heat and cold exposure of the spotted wing drosophila, Drosophila suzukii

    PubMed Central

    Enriquez, Thomas

    2017-01-01

    The spotted wing Drosophila, Drosophila suzukii, is a new pest in Europe and America which causes severe damages, mostly to stone fruit crops. Temperature and humidity are among the most important abiotic factors governing insect development and fitness. In many situations, temperature can become stressful thus compromising survival. The ability to cope with thermal stress depends on basal level of thermal tolerance. Basic knowledge on temperature-dependent mortality of D. suzukii is essential to facilitate management of this pest. The objective of the present study was to investigate D. suzukii basal cold and heat tolerance. Adults and pupae were subjected to six low temperatures (−5–7.5 °C) and seven high temperatures (30–37 °C) for various durations, and survival-time-temperature relationships were investigated. Data showed that males were globally more cold tolerant than females. At temperature above 5 °C, adult cold mortality became minor even after prolonged exposures (e.g., only 20% mortality after one month at 7.5 °C). Heat tolerance of males was lower than that of females at the highest tested temperatures (34, 35 and 37 °C). Pupae appeared much less cold tolerant than adults at all temperatures (e.g., Lt50 at 5° C: 4–5 d for adults vs. 21 h for pupae). Pupae were more heat tolerant than adults at the most extreme high temperatures (e.g., Lt50 at 37 °C: 30 min for adults vs. 4 h for pupae). The pupal thermal tolerance was further investigated under low vs. high humidity. Low relative humidity did not affect pupal cold survival, but it reduced survival under heat stress. Overall, this study shows that survival of D. suzukii under heat and cold conditions can vary with stress intensity, duration, humidity, sex and stage, and the methodological approach used here, which was based on thermal tolerance landscapes, provides a comprehensive description of D. suzukiithermal tolerance and limits. PMID:28348931

  10. Studies of the repair of radiation-induced genetic damage in Drosophila. Annual progress report, February 1-July 1, 1983

    SciTech Connect

    Not Available

    1983-01-01

    Research progress is reported in the following areas: (1) characterization of a photo-repair deficient mutant in Drosophila; (2) the role of poly(ADPR)polymerase in Drosophila repair; and (3) service functions. (ACR)

  11. In vivo chromatin accessibility correlates with gene silencing in Drosophila.

    PubMed Central

    Boivin, A; Dura, J M

    1998-01-01

    Gene silencing by heterochromatin is a well-known phenomenon that, in Drosophila, is called position effect variegation (PEV). The long-held hypothesis that this gene silencing is associated with an altered chromatin structure received direct support only recently. Another gene-silencing phenomenon in Drosophila, although similar in its phenotype of variegation, has been shown to be associated with euchromatic sequences and is dependent on developmental regulators of the Polycomb group (Pc-G) of gene products. One model proposes that the Pc-G products may cause a local heterochromatinization that maintains a repressed state of transcription of their target genes. Here, we test these models by measuring the accessibility of white or miniwhite sequences, in different contexts, to the Escherichia coli dam DNA methyltransferase in vivo. We present evidence that PEV and Pc-G-mediated repression mechanisms, although based on different protein factors, may indeed involve similar higher-order chromatin structure. PMID:9832530

  12. Electron spin changes during general anesthesia in Drosophila

    PubMed Central

    Turin, Luca; Skoulakis, Efthimios M. C.; Horsfield, Andrew P.

    2014-01-01

    We show that the general anesthetics xenon, sulfur hexafluoride, nitrous oxide, and chloroform cause rapid increases of different magnitude and time course in the electron spin content of Drosophila. With the exception of CHCl3, these changes are reversible. Anesthetic-resistant mutant strains of Drosophila exhibit a different pattern of spin responses to anesthetic. In two such mutants, the spin response to CHCl3 is absent. We propose that these spin changes are caused by perturbation of the electronic structure of proteins by general anesthetics. Using density functional theory, we show that general anesthetics perturb and extend the highest occupied molecular orbital of a nine-residue α-helix. The calculated perturbations are qualitatively in accord with the Meyer–Overton relationship and some of its exceptions. We conclude that there may be a connection between spin, electron currents in cells, and the functioning of the nervous system. PMID:25114249

  13. Vision in Drosophila: seeing the world through a model's eyes.

    PubMed

    Paulk, Angelique; Millard, S Sean; van Swinderen, Bruno

    2013-01-01

    The fruit fly, Drosophila melanogaster, has been used for decades as a genetic model for unraveling mechanisms of development and behavior. In order to efficiently assign gene functions to cellular and behavioral processes, early measures were often necessarily simple. Much of what is known of developmental pathways was based on disrupting highly regular structures, such as patterns of cells in the eye. Similarly, reliable visual behaviors such as phototaxis and motion responses provided a solid foundation for dissecting vision. Researchers have recently begun to examine how this model organism responds to more complex or naturalistic stimuli by designing novel paradigms that more closely mimic visual behavior in the wild. Alongside these advances, the development of brain-recording strategies allied with novel genetic tools has brought about a new era of Drosophila vision research where neuronal activity can be related to behavior in the natural world.

  14. Preparation of Drosophila Polytene Chromosome Squashes for Antibody Labeling

    PubMed Central

    Cai, Weili; Jin, Ye; Girton, Jack; Johansen, Jorgen; Johansen, Kristen M.

    2010-01-01

    Drosophila has long been a favorite model system for studying the relationship between chromatin structure and gene regulation due to the cytological advantages provided by the giant salivary gland polytene chromosomes of third instar larvae. In this tissue the chromosomes undergo many rounds of replication in the absence of cell division giving rise to approximately 1000 copies. The DNA remains aligned after each replicative cycle resulting in greatly enlarged chromosomes that provide a unique opportunity to correlate chromatin morphology with the localization of specific proteins. Consequently, there has been a high level of interest in defining the epigenetic modifications present at different genes and at different stages of the transcription process. An important tool for such studies is the labeling of polytene chromosomes with antibodies to the enzyme, transcription factor, or histone modification of interest. This video protocol illustrates the squash technique used in the Johansen laboratory to prepare Drosophila polytene chromosomes for antibody labeling. PMID:20145604

  15. Live imaging of GFP-labeled proteins in Drosophila oocytes.

    PubMed

    Pokrywka, Nancy Jo

    2013-03-29

    The Drosophila oocyte has been established as a versatile system for investigating fundamental questions such as cytoskeletal function, cell organization, and organelle structure and function. The availability of various GFP-tagged proteins means that many cellular processes can be monitored in living cells over the course of minutes or hours, and using this technique, processes such as RNP transport, epithelial morphogenesis, and tissue remodeling have been described in great detail in Drosophila oocytes. The ability to perform video imaging combined with a rich repertoire of mutants allows an enormous variety of genes and processes to be examined in incredible detail. One such example is the process of ooplasmic streaming, which initiates at mid-oogenesis. This vigorous movement of cytoplasmic vesicles is microtubule and kinesin-dependent and provides a useful system for investigating cytoskeleton function at these stages. Here I present a protocol for time lapse imaging of living oocytes using virtually any confocal microscopy setup.

  16. Conserved family of glycerol kinase loci in Drosophila melanogaster

    PubMed Central

    Martinez Agosto, Julian A.; McCabe, Edward R.B.

    2009-01-01

    Glycerol kinase (GK) is an enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol, the rate-limiting step in glycerol utilization. We analyzed the genome of the model organism Drosophila melanogaster and identified five GK orthologs, including two loci with sequence homology to the mammalian Xp21 GK protein. Using a combination of sequence analysis and evolutionary comparisons of orthologs between species, we characterized functional domains in the protein required for GK activity. Our findings include additional conserved domains that suggest novel nuclear and mitochondrial functions for glycerol kinase in apoptosis and transcriptional regulation. Investigation of GK function in Drosophila will inform us about the role of this enzyme in development and will provide us with a tool to examine genetic modifiers of human metabolic disorders. PMID:16545593

  17. [Ecological imprinting and protein biosynthesis. Experiments with Drosophila melanogaster Meigen].

    PubMed

    Laudien, H; Iken, H H

    1977-06-01

    According to the "host selection principle", butterflies and other herbivorous insects preferentially lay their eggs on those plant races that they fed on when young. This is also true for karpophagic and parasitic insects. The selection of specific chemical conditions could be either inherited or acquired. If learned information determines host selection, we have a case of imprinting, as a) reception and use of the information are not simultaneous, b) there is no reward. In experiments with Drosophila melanogaster we marked the egg deposition medium with ethanol, acetic acid, peppermint oil, or benzaldehyd. The flies spontaneously prefer mediums with ethanol and acetic acid, and reject peppermint oil and benzaldehyd. If they are reared in one of these media, the preference for it is increased, or the rejection rate lowered. Rearing with actinomycin C neutralizes the effect of the other markers. It is concluded that actinomycin C blocks imprinting on the egg deposition substrate in Drosophila melanogaster.

  18. Imaging Approaches to Investigate Myonuclear Positioning in Drosophila

    PubMed Central

    Azevedo, Mafalda; Schulman, Victoria K.; Folker, Eric; Balakrishnan, Mridula; Baylies, Mary

    2016-01-01

    In the skeletal muscle, nuclei are positioned at the periphery of each myofiber and are evenly distributed along its length. Improper positioning of myonuclei has been correlated with muscle disease and decreased muscle function. Several mechanisms required for regulating nuclear position have been identified using the fruit fly, Drosophila melanogaster. The conservation of the myofiber between the fly and vertebrates, the availability of advanced genetic tools, and the ability to visualize dynamic processes using fluorescent proteins in vivo makes the fly an excellent system to study myonuclear positioning. This chapter describes time-lapse and fixed imaging methodologies using both the Drosophila embryo and the larva to investigate mechanisms of myonuclear positioning. PMID:27147050

  19. Bimodal regulation of RAF by CNK in Drosophila

    PubMed Central

    Douziech, Mélanie; Roy, François; Laberge, Gino; Lefrançois, Martin; Armengod, Anne-Valérie; Therrien, Marc

    2003-01-01

    Connector enhancer of KSR (CNK) is a multidomain-containing protein previously identified as a positive regulator of the RAS/MAPK pathway in Drosophila. Using transfection experiments and an RNAi-based rescue assay in Drosophila S2 cells, we demonstrate that CNK has antagonistic properties with respect to RAF activity. We show that CNK’s N-terminal region contains two domains (SAM and CRIC) that are essential for RAF function. Unexpectedly, we also report that the C-terminal region of CNK contains a short bipartite element that strongly inhibits RAF catalytic function. Interestingly, CNK’s opposite properties appear to prevent signaling leakage from RAF to MEK in the absence of upstream signals, but then transforms into a potent RAF activator upon signal activation. Together, these findings suggest that CNK not only participates in the elusive RAF activation process, but might also contribute to the switch-like behavior of the MAPK module. PMID:14517245

  20. Clonal development and organization of the adult Drosophila central brain

    PubMed Central

    Yu, Hung-Hsiang; Awasaki, Takeshi; Schroeder, Mark David; Long, Fuhui; Yang, Jacob S.; He, Yisheng; Ding, Peng; Kao, Jui-Chun; Wu, Gloria Yueh-Yi; Peng, Hanchuan; Myers, Gene; Lee, Tzumin

    2013-01-01

    Summary Background The insect brain can be divided into neuropils that are formed by neurites of both local and remote origin. The complexity of the interconnections obscures how these neuropils are established and interconnected through development. The Drosophila central brain develops from a fixed number of neuroblasts (NBs) that deposit neurons in regional clusters. Results By determining individual NB clones and pursuing their projections into specific neuropils we unravel the regional development of the brain neural network. Exhaustive clonal analysis revealed 95 stereotyped neuronal lineages with characteristic cell body locations and neurite trajectories. Most clones show complex projection patterns, but despite the complexity, neighboring clones often co-innervate the same local neuropil(s) and further target a restricted set of distant neuropils. Conclusions These observations argue for regional clonal development of both neuropils and neuropil connectivity throughout the Drosophila central brain. PMID:23541733

  1. GABAA receptor-expressing neurons promote consumption in Drosophila melanogaster

    PubMed Central

    Cheung, Samantha K.

    2017-01-01

    Feeding decisions are highly plastic and bidirectionally regulated by neurons that either promote or inhibit feeding. In Drosophila melanogaster, recent studies have identified four GABAergic interneurons that act as critical brakes to prevent incessant feeding. These GABAergic neurons may inhibit target neurons that drive consumption. Here, we tested this hypothesis by examining GABA receptors and neurons that promote consumption. We find that Resistance to dieldrin (RDL), a GABAA type receptor, is required for proper control of ingestion. Knockdown of Rdl in a subset of neurons causes overconsumption of tastants. Acute activation of these neurons is sufficient to drive consumption of appetitive substances and non-appetitive substances and acute silencing of these neurons decreases consumption. Taken together, these studies identify GABAA receptor-expressing neurons that promote Drosophila ingestive behavior and provide insight into feeding regulation. PMID:28362856

  2. A genomic approach to myoblast fusion in Drosophila

    PubMed Central

    Estrada, Beatriz; Michelson, Alan M.

    2009-01-01

    Summary We have developed an integrated genetic, genomic and computational approach to identify and characterize genes involved in myoblast fusion in Drosophila. We first used fluorescence activated cell sorting to purify mesodermal cells both from wild-type embryos and from twelve variant genotypes in which muscle development is perturbed in known ways. Then, we obtained gene expression profiles for the purified cells by hybridizing isolated mesodermal RNA to Affymetrix GeneChip arrays. These data were subsequently compounded into a statistical meta-analysis that predicts myoblast subtype-specific gene expression signatures that were later validated by in situ hybridization experiments. Finally, we analyzed the myogenic functions of a subset of these myoblast genes using a double-stranded RNA interference assay in living embryos expressing green fluorescent protein under control of a muscle-specific promoter. This experimental strategy led to the identification of several previously uncharacterized genes required for myoblast fusion in Drosophila. PMID:18979251

  3. Learning the specific quality of taste reinforcement in larval Drosophila.

    PubMed

    Schleyer, Michael; Miura, Daisuke; Tanimura, Teiichi; Gerber, Bertram

    2015-01-27

    The only property of reinforcement insects are commonly thought to learn about is its value. We show that larval Drosophila not only remember the value of reinforcement (How much?), but also its quality (What?). This is demonstrated both within the appetitive domain by using sugar vs amino acid as different reward qualities, and within the aversive domain by using bitter vs high-concentration salt as different qualities of punishment. From the available literature, such nuanced memories for the quality of reinforcement are unexpected and pose a challenge to present models of how insect memory is organized. Given that animals as simple as larval Drosophila, endowed with but 10,000 neurons, operate with both reinforcement value and quality, we suggest that both are fundamental aspects of mnemonic processing-in any brain.

  4. Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory.

    PubMed

    Shuai, Yichun; Hirokawa, Areekul; Ai, Yulian; Zhang, Min; Li, Wanhe; Zhong, Yi

    2015-12-01

    Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-β'1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts.

  5. Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory

    PubMed Central

    Shuai, Yichun; Hirokawa, Areekul; Ai, Yulian; Zhang, Min; Li, Wanhe; Zhong, Yi

    2015-01-01

    Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-β′1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts. PMID:26627257

  6. Conventional and Non-Conventional Drosophila Toll Signaling

    PubMed Central

    Lindsay, Scott A.; Wasserman, Steven A.

    2013-01-01

    The discovery of Toll in Drosophila and of the remarkable conservation in pathway composition and organization catalyzed a transformation in our understanding of innate immune recognition and response. At the center of that picture is a cascade of interactions in which specific microbial cues activate Toll receptors, which then transmit signals driving transcription factor nuclear localization and activity. Experiments gave substance to the vision of pattern recognition receptors, linked phenomena in development, gene regulation, and immunity into a coherent whole, and revealed a rich set of variations for identifying non-self and responding effectively. More recently, research in Drosophila has illuminated the positive and negative regulation of Toll activation, the organization of signaling events at and beneath membranes, the sorting of information flow, and the existence of non-conventional signaling via Toll-related receptors. Here, we provide an overview of the Toll pathway of flies and highlight these ongoing realms of research. PMID:23632253

  7. Effect of a Magnetic Field on Drosophila under Supercooled Conditions

    PubMed Central

    Mihara, Makoto; Terayama, Hayato; Hatayama, Naoyuki; Hayashi, Shogo; Matsushita, Masayuki; Itoh, Masahiro

    2012-01-01

    Under subzero degree conditions, free water contained in biological cells tends to freeze and then most living things die due to low temperatures. We examined the effect of a variable magnetic field on Drosophila under supercooled conditions (a state in which freezing is not caused even below the freezing point). Under such supercooled conditions with the magnetic field at 0°C for 72 hours, −4°C for 24 hours and −8°C for 1 hour, the Drosophila all survived, while all conversely died under the supercooled conditions without the magnetic field. This result indicates a possibility that the magnetic field can reduce cell damage caused due to low temperatures in living things. PMID:23284809

  8. Separate TRP channels mediate amplification and transduction in drosophila

    NASA Astrophysics Data System (ADS)

    Lehnert, Brendan P.; Baker, Allison E.; Wilson, Rachel I.

    2015-12-01

    Auditory receptor cells rely on mechanically-gated channels to transform sound stimuli into neural activity. Several TRP channels have been implicated in Drosophila auditory transduction, but mechanistic studies have been hampered by the inability to record subthreshold signals from receptor neurons. We developed a non-invasive method for measuring these signals by recording from a central neuron that is electrically coupled to a genetically-defined population of auditory receptors. We find that the TRPN family member NompC, which is necessary for the active amplification of motion by the auditory organ, is not required for transduction. Instead, NompC sensitizes the transduction complex to movement and precisely regulates the static forces on the complex. In contrast, the TRPV channels Nanchung and Inactive are required for responses to sound, suggesting they are components of the transduction complex. Thus, transduction and active amplification are genetically separable processes in Drosophila hearing.

  9. Functional analysis of an olfactory receptor in Drosophila melanogaster

    PubMed Central

    Störtkuhl, Klemens F.; Kettler, Raffael

    2001-01-01

    Fifty nine candidate olfactory receptor (Or) genes have recently been identified in Drosophila melanogaster, one of which is Or43a. In wild-type flies, Or43a is expressed at the distal edge of the third antennal segment in about 15 Or neurons. To identify ligands for the receptor we used the Gal4/UAS system to misexpress Or43a in the third antennal segment. Or43a mRNA expression in the antenna of transformed and wild-type flies was visualized by in situ hybridization with a digoxigenin-labeled probe. Electroantennogram recordings from transformed and wild-type flies were used to identify cyclohexanol, cyclohexanone, benzaldehyde, and benzyl alcohol as ligands for the Or43a. This in vivo analysis reveals functional properties of one member of the recently isolated Or family in Drosophila and will provide further insight into our understanding of olfactory coding. PMID:11481495

  10. Transcriptomic response of Drosophila melanogaster pupae developed in hypergravity.

    PubMed

    Hateley, Shannon; Hosamani, Ravikumar; Bhardwaj, Shilpa R; Pachter, Lior; Bhattacharya, Sharmila

    2016-10-01

    Altered gravity can perturb normal development and induce corresponding changes in gene expression. Understanding this relationship between the physical environment and a biological response is important for NASA's space travel goals. We use RNA-Seq and qRT-PCR techniques to profile changes in early Drosophila melanogaster pupae exposed to chronic hypergravity (3g, or three times Earth's gravity). During the pupal stage, D. melanogaster rely upon gravitational cues for proper development. Assessing gene expression changes in the pupae under altered gravity conditions helps highlight gravity-dependent genetic pathways. A robust transcriptional response was observed in hypergravity-treated pupae compared to controls, with 1513 genes showing a significant (q<0.05) difference in gene expression. Five major biological processes were affected: ion transport, redox homeostasis, immune response, proteolysis, and cuticle development. This outlines the underlying molecular and biological changes occurring in Drosophila pupae in response to hypergravity; gravity is important for many biological processes on Earth.

  11. A pulsed magnetic stress applied to Drosophila melanogaster flies

    NASA Astrophysics Data System (ADS)

    Delle Side, D.; Bozzetti, M. P.; Friscini, A.; Giuffreda, E.; Nassisi, V.; Specchia, V.; Velardi, L.

    2014-04-01

    We report the development of a system to feed pulsed magnetic stress to biological samples. The device is based on a RLC circuit that transforms the energy stored in a high voltage capacitor into a magnetic field inside a coil. The field has been characterized and we found that charging the capacitor with 24 kV results in a peak field of 0.4 T. In order to test its effect, we applied such a stress to the Drosophila melanogaster model and we examined its bio-effects. We analysed, in the germ cells, the effects on the control of specific DNA repetitive sequences that are activated after different environmental stresses. The deregulation of these sequences causes genomic instability and chromosomes breaks leading to sterility. The magnetic field treatment did not produce effects on repetitive sequences in the germ cells of Drosophila. Hence, this field doesn't produce deleterious effects linked to repetitive sequences derepression.

  12. Multimodal chemosensory circuits controlling male courtship in Drosophila

    PubMed Central

    Clowney, E. Josephine; Iguchi, Shinya; Bussell, Jennifer J.; Scheer, Elias; Ruta, Vanessa

    2015-01-01

    Summary Throughout the animal kingdom, internal states generate long-lasting and self-perpetuating chains of behavior. In Drosophila, males instinctively pursue females with a lengthy and elaborate courtship ritual triggered by activation of sexually dimorphic P1 interneurons. Gustatory pheromones are thought to activate P1 neurons but the circuit mechanisms that dictate their sensory responses to gate entry into courtship remain unknown. Here, we use circuit mapping and in vivo functional imaging techniques to trace gustatory and olfactory pheromone circuits to their point of convergence onto P1 neurons and reveal how their combined input underlies selective tuning to appropriate sexual partners. We identify inhibition, even in response to courtship-promoting pheromones, as a key circuit element that tunes and tempers P1 neuron activity. Our results suggest a circuit mechanism in which balanced excitation and inhibition underlie discrimination of prospective mates and stringently regulate the transition to courtship in Drosophila. PMID:26279475

  13. The anoctamin family channel subdued mediates thermal nociception in Drosophila.

    PubMed

    Jang, Wijeong; Kim, Ji Young; Cui, Shanyu; Jo, Juyeon; Lee, Byoung-Cheol; Lee, Yeonwoo; Kwon, Ki-Sun; Park, Chul-Seung; Kim, Changsoo

    2015-01-23

    Calcium-permeable and thermosensitive transient receptor potential (TRP) channels mediate the nociceptive transduction of noxious temperature in Drosophila nociceptors. However, the underlying molecular mechanisms are not completely understood. Here we find that Subdued, a calcium-activated chloride channel of the Drosophila anoctamin family, functions in conjunction with the thermo-TRPs in thermal nociception. Genetic analysis with deletion and the RNAi-mediated reduction of subdued show that subdued is required for thermal nociception in nociceptors. Further genetic analysis of subdued mutant and thermo-TRP mutants show that they interact functionally in thermal nociception. We find that Subdued expressed in heterologous cells mediates a strong chloride conductance in the presence of both heat and calcium ions. Therefore, our analysis suggests that Subdued channels may amplify the nociceptive neuronal firing that is initiated by thermo-TRP channels in response to thermal stimuli.

  14. Probing Mechanisms That Underlie Human Neurodegenerative Diseases in Drosophila

    PubMed Central

    Jaiswal, M.; Sandoval, H.; Zhang, K.; Bayat, V.; Bellen, H.J.

    2013-01-01

    The fruit fly, Drosophila melanogaster, is an excellent organism for the study of the genetic and molecular basis of metazoan development. Drosophila provides numerous tools and reagents to unravel the molecular and cellular functions of genes that cause human disease, and the past decade has witnessed a significant expansion of the study of neurodegenerative disease mechanisms in flies. Here we review the interplay between oxidative stress and neuronal toxicity. We cover some of the studies that show how proteasome degradation of protein aggregates, autophagy, mitophagy, and lysosomal function affect the quality control mechanisms required for neuronal survival. We discuss how forward genetic screens in flies have led to the isolation of a few loci that cause neurodegeneration, paving the way for large-scale systematic screens to identify such loci in flies as well as promoting gene discovery in humans. PMID:22974305

  15. Glial dysfunction causes age-related memory impairment in Drosophila.

    PubMed

    Yamazaki, Daisuke; Horiuchi, Junjiro; Ueno, Kohei; Ueno, Taro; Saeki, Shinjiro; Matsuno, Motomi; Naganos, Shintaro; Miyashita, Tomoyuki; Hirano, Yukinori; Nishikawa, Hiroyuki; Taoka, Masato; Yamauchi, Yoshio; Isobe, Toshiaki; Honda, Yoshiko; Kodama, Tohru; Masuda, Tomoko; Saitoe, Minoru

    2014-11-19

    Several aging phenotypes, including age-related memory impairment (AMI), are thought to be caused by cumulative oxidative damage. In Drosophila, age-related impairments in 1 hr memory can be suppressed by reducing activity of protein kinase A (PKA). However, the mechanism for this effect has been unclear. Here we show that decreasing PKA suppresses AMI by reducing activity of pyruvate carboxylase (PC), a glial metabolic enzyme whose amounts increase upon aging. Increased PC activity causes AMI through a mechanism independent of oxidative damage. Instead, increased PC activity is associated with decreases in D-serine, a glia-derived neuromodulator that regulates NMDA receptor activity. D-serine feeding suppresses both AMI and memory impairment caused by glial overexpression of dPC, indicating that an oxidative stress-independent dysregulation of glial modulation of neuronal activity contributes to AMI in Drosophila.

  16. Glial β-oxidation regulates Drosophila energy metabolism.

    PubMed

    Schulz, Joachim G; Laranjeira, Antonio; Van Huffel, Leen; Gärtner, Annette; Vilain, Sven; Bastianen, Jarl; Van Veldhoven, Paul P; Dotti, Carlos G

    2015-01-15

    The brain's impotence to utilize long-chain fatty acids as fuel, one of the dogmas in neuroscience, is surprising, since the nervous system is the tissue most energy consuming and most vulnerable to a lack of energy. Challenging this view, we here show in vivo that loss of the Drosophila carnitine palmitoyltransferase 2 (CPT2), an enzyme required for mitochondrial β-oxidation of long-chain fatty acids as substrates for energy production, results in the accumulation of triacylglyceride-filled lipid droplets in adult Drosophila brain but not in obesity. CPT2 rescue in glial cells alone is sufficient to restore triacylglyceride homeostasis, and we suggest that this is mediated by the release of ketone bodies from the rescued glial cells. These results demonstrate that the adult brain is able to catabolize fatty acids for cellular energy production.

  17. DROSOPHILA SODIUM CHANNEL MUTATIONS: CONTRIBUTIONS TO SEIZURE-SUSCEPTIBILITY

    PubMed Central

    Kroll, Jason R.; Saras, Arunesh; Tanouye, Mark A.

    2015-01-01

    This paper reviews Drosophila voltage-gated Na+ channel mutations encoded by the para (paralytic) gene and their contributions to seizure disorders in the fly. Numerous mutations cause seizure-sensitivity, for example, parabss1, with phenotypes that resemble human intractable epilepsy in some aspects. Seizure phenotypes are also seen with human GEFS+ spectrum mutations that have been knocked into the Drosophila para gene, paraGEFS+ and paraDS alleles. Other para mutations, paraST76 and paraJS act as seizure-suppressor mutations reverting seizure phenotypes in other mutants. Seizure-like phenotypes are observed from mutations and other conditions that cause a persistent Na+ current through either changes in mRNA splicing or protein structure. PMID:26093037

  18. Heterochromatin remodeling by CDK12 contributes to learning in Drosophila

    PubMed Central

    Pan, Lixia; Xie, Wenbing; Li, Kai-Le; Yang, Zhihao; Xu, Jiang; Zhang, Wenhao; Liu, Lu-Ping; Ren, Xingjie; He, Zhimin; Wu, Junyu; Sun, Jin; Wei, Hui-Min; Wang, Daliang; Xie, Wei; Li, Wei; Ni, Jian-Quan; Sun, Fang-Lin

    2015-01-01

    Dynamic regulation of chromatin structure is required to modulate the transcription of genes in eukaryotes. However, the factors that contribute to the plasticity of heterochromatin structure are elusive. Here, we report that cyclin-dependent kinase 12 (CDK12), a transcription elongation-associated RNA polymerase II (RNAPII) kinase, antagonizes heterochromatin enrichment in Drosophila chromosomes. Notably, loss of CDK12 induces the ectopic accumulation of heterochromatin protein 1 (HP1) on euchromatic arms, with a prominent enrichment on the X chromosome. Furthermore, ChIP and sequencing analysis reveals that the heterochromatin enrichment on the X chromosome mainly occurs within long genes involved in neuronal functions. Consequently, heterochromatin enrichment reduces the transcription of neuronal genes in the adult brain and results in a defect in Drosophila courtship learning. Taken together, these results define a previously unidentified role of CDK12 in controlling the epigenetic transition between euchromatin and heterochromatin and suggest a chromatin regulatory mechanism in neuronal behaviors. PMID:26508632

  19. Genotoxicity of copper oxide nanoparticles in Drosophila melanogaster.

    PubMed

    Carmona, Erico R; Inostroza-Blancheteau, Claudio; Obando, Veroska; Rubio, Laura; Marcos, Ricard

    2015-09-01

    Copper oxide nanoparticles (CuONPs) are used as semiconductors, catalysts, gas sensors, and antimicrobial agents. We have used the comet and wing-spot assays in Drosophila melanogaster to assess the genotoxicity of CuONPs and ionic copper (CuSO4). Lipid peroxidation analysis was also performed (Thiobarbituric Acid Assay, TBARS). In larval hemocytes, both CuONPs and CuSO4 caused significant dose-dependent increases in DNA damage (comet assay). In the wing-spot assay, an increase in the frequency of mutant spots was observed in the wings of the adults; CuONPs were more effective than was CuSO4. Both agents induced TBARS; again, CuONPs were more active than was CuSO4. The results indicate that CuONPs are genotoxic in Drosophila, and these effects may be mediated by oxidative stress. Most of the effects appear to be related to the presence of copper ions.

  20. Glial β-Oxidation regulates Drosophila Energy Metabolism

    PubMed Central

    Schulz, Joachim G.; Laranjeira, Antonio; Van Huffel, Leen; Gärtner, Annette; Vilain, Sven; Bastianen, Jarl; Van Veldhoven, Paul P.; Dotti, Carlos G.

    2015-01-01

    The brain's impotence to utilize long-chain fatty acids as fuel, one of the dogmas in neuroscience, is surprising, since the nervous system is the tissue most energy consuming and most vulnerable to a lack of energy. Challenging this view, we here show in vivo that loss of the Drosophila carnitine palmitoyltransferase 2 (CPT2), an enzyme required for mitochondrial β-oxidation of long-chain fatty acids as substrates for energy production, results in the accumulation of triacylglyceride-filled lipid droplets in adult Drosophila brain but not in obesity. CPT2 rescue in glial cells alone is sufficient to restore triacylglyceride homeostasis, and we suggest that this is mediated by the release of ketone bodies from the rescued glial cells. These results demonstrate that the adult brain is able to catabolize fatty acids for cellular energy production. PMID:25588812