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Sample records for argonaute2 suppresses drosophila

  1. Variation and Evolution in the Glutamine-Rich Repeat Region of Drosophila Argonaute-2.

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    Palmer, William H; Obbard, Darren J

    2016-01-01

    RNA interference pathways mediate biological processes through Argonaute-family proteins, which bind small RNAs as guides to silence complementary target nucleic acids . In insects and crustaceans Argonaute-2 silences viral nucleic acids, and therefore acts as a primary effector of innate antiviral immunity. Although the function of the major Argonaute-2 domains, which are conserved across most Argonaute-family proteins, are known, many invertebrate Argonaute-2 homologs contain a glutamine-rich repeat (GRR) region of unknown function at the N-terminus . Here we combine long-read amplicon sequencing of Drosophila Genetic Reference Panel (DGRP) lines with publicly available sequence data from many insect species to show that this region evolves extremely rapidly and is hyper-variable within species. We identify distinct GRR haplotype groups in Drosophila melanogaster, and suggest that one of these haplotype groups has recently risen to high frequency in a North American population. Finally, we use published data from genome-wide association studies of viral resistance in D. melanogaster to test whether GRR haplotypes are associated with survival after virus challenge. We find a marginally significant association with survival after challenge with Drosophila C Virus in the DGRP, but we were unable to replicate this finding using lines from the Drosophila Synthetic Population Resource panel.

  2. Natural variation of the amino-terminal glutamine-rich domain in Drosophila argonaute2 is not associated with developmental defects.

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    Daniel Hain

    Full Text Available The Drosophila argonaute2 (ago2 gene plays a major role in siRNA mediated RNA silencing pathways. Unlike mammalian Argonaute proteins, the Drosophila protein has an unusual amino-terminal domain made up largely of multiple copies of glutamine-rich repeats (GRRs. We report here that the ago2 locus produces an alternative transcript that encodes a putative short isoform without this amino-terminal domain. Several ago2 mutations previously reported to be null alleles only abolish expression of the long, GRR-containing isoform. Analysis of drop out (dop mutations had previously suggested that variations in GRR copy number result in defects in RNAi and embryonic development. However, we find that dop mutations genetically complement transcript-null alleles of ago2 and that ago2 alleles with variant GRR copy numbers support normal development. In addition, we show that the assembly of the central RNAi machinery, the RISC (RNA induced silencing complex, is unimpaired in embryos when GRR copy number is altered. In fact, we find that GRR copy number is highly variable in natural D. melanogaster populations as well as in laboratory strains. Finally, while many other insects share an extensive, glutamine-rich Ago2 amino-terminal domain, its primary sequence varies drastically between species. Our data indicate that GRR variation does not modulate an essential function of Ago2 and that the amino-terminal domain of Ago2 is subject to rapid evolution.

  3. The Crystal Structure of Human Argonaute2

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    Schirle, Nicole T.; MacRae, Ian J. (Scripps)

    2012-07-18

    Argonaute proteins form the functional core of the RNA-induced silencing complexes that mediate RNA silencing in eukaryotes. The 2.3 angstrom resolution crystal structure of human Argonaute2 (Ago2) reveals a bilobed molecule with a central cleft for binding guide and target RNAs. Nucleotides 2 to 6 of a heterogeneous mixture of guide RNAs are positioned in an A-form conformation for base pairing with target messenger RNAs. Between nucleotides 6 and 7, there is a kink that may function in microRNA target recognition or release of sliced RNA products. Tandem tryptophan-binding pockets in the PIWI domain define a likely interaction surface for recruitment of glycine-tryptophan-182 (GW182) or other tryptophan-rich cofactors. These results will enable structure-based approaches for harnessing the untapped therapeutic potential of RNA silencing in humans.

  4. Selective anticancer agents suppress aging in Drosophila.

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    Danilov, Anton; Shaposhnikov, Mikhail; Plyusnina, Ekaterina; Kogan, Valeria; Fedichev, Peter; Moskalev, Alexey

    2013-09-01

    Mutations of the PI3K, TOR, iNOS, and NF-κB genes increase lifespan of model organisms and reduce the risk of some aging-associated diseases. We studied the effects of inhibitors of PI3K (wortmannin), TOR (rapamycin), iNOS (1400W), NF-κB (pyrrolidin dithiocarbamate and QNZ), and the combined effects of inhibitors: PI3K (wortmannin) and TOR (rapamycin), NF-κB (pyrrolidin dithiocarbamates) and PI3K (wortmannin), NF-κB (pyrrolidine dithiocarbamates) and TOR (rapamycin) on Drosophila melanogaster lifespan and quality of life (locomotor activity and fertility). Our data demonstrate that pharmacological inhibition of PI3K, TOR, NF-κB, and iNOS increases lifespan of Drosophila without decreasing quality of life. The greatest lifespan expanding effect was achieved by a combination of rapamycin (5 μM) and wortmannin (5 μM) (by 23.4%). The bioinformatic analysis (KEGG, REACTOME.PATH, DOLite, and GO.BP) showed the greatest aging-suppressor activity of rapamycin, consistent with experimental data. PMID:24096697

  5. DICER-ARGONAUTE2 complex in continuous fluorogenic assays of RNA interference enzymes.

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    Mark A Bernard

    Full Text Available Mechanistic studies of RNA processing in the RNA-Induced Silencing Complex (RISC have been hindered by lack of methods for continuous monitoring of enzymatic activity. "Quencherless" fluorogenic substrates of RNAi enzymes enable continuous monitoring of enzymatic reactions for detailed kinetics studies. Recombinant RISC enzymes cleave the fluorogenic substrates targeting human thymidylate synthase (TYMS and hypoxia-inducible factor 1-α subunit (HIF1A. Using fluorogenic dsRNA DICER substrates and fluorogenic siRNA, DICER+ARGONAUTE2 mixtures exhibit synergistic enzymatic activity relative to either enzyme alone, and addition of TRBP does not enhance the apparent activity. Titration of AGO2 and DICER in enzyme assays suggests that AGO2 and DICER form a functional high-affinity complex in equimolar ratio. DICER and DICER+AGO2 exhibit Michaelis-Menten kinetics with DICER substrates. However, AGO2 cannot process the fluorogenic siRNA without DICER enzyme, suggesting that AGO2 cannot self-load siRNA into its active site. The DICER+AGO2 combination processes the fluorogenic siRNA substrate (Km=74 nM with substrate inhibition kinetics (Ki=105 nM, demonstrating experimentally that siRNA binds two different sites that affect Dicing and AGO2-loading reactions in RISC. This result suggests that siRNA (product of DICER bound in the active site of DICER may undergo direct transfer (as AGO2 substrate to the active site of AGO2 in the DICER+AGO2 complex. Competitive substrate assays indicate that DICER+AGO2 cleavage of fluorogenic siRNA is specific, since unlabeled siRNA and DICER substrates serve as competing substrates that cause a concentration-dependent decrease in fluorescent rates. Competitive substrate assays of a series of DICER substrates in vitro were correlated with cell-based assays of HIF1A mRNA knockdown (log-log slope=0.29, suggesting that improved DICER substrate designs with 10-fold greater processing by the DICER+AGO2 complex can provide a

  6. Argonaute-2-null embryonic stem cells are retarded in self-renewal and differentiation

    Indian Academy of Sciences (India)

    P Chandra Shekar; Adnan Naim; D Partha Sarathi; Satish Kumar

    2011-09-01

    RNA interference (RNAi) pathways regulate self-renewal and differentiation of embryonic stem (ES) cells. Argonaute 2 (Ago2) is a vital component of RNA-induced silencing complex (RISC) and the only Ago protein with slicer activity. We generated Ago2-deficient ES cells by conditional gene targeting. Ago2-deficient ES cells are defective in the small-RNA-mediated gene silencing and are significantly compromised in biogenesis of mature microRNA. The self-renewal rate of Ago2-deficient ES cells is affected due to failure of silencing of Cdkn1a by ES-cell-specific microRNAs (miRNA) in the absence of Ago2. Interestingly, unlike Dicer- and Dgcr8-deficient ES cells, they differentiate to all three germ layers both in vivo and in vitro. However, early differentiation of Ago2-deficient ES cells is delayed by 2–4 days as indicated by persistence of higher levels of self-renewal/ pluripotency markers during differentiation. Further, appearance of morphological and differentiation markers is also delayed during the differentiation. In this study we show that Ago2 is essential for normal self-renewal and differentiation. Also, our data suggest that self-renewal and differentiation of ES cells are regulated by both siRNA and miRNA pathways.

  7. Novel Insights into Guide RNA 5′-Nucleoside/Tide Binding by Human Argonaute 2

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    Munishikha Kalia

    2015-12-01

    Full Text Available The human Argonaute 2 (hAgo2 protein is a key player of RNA interference (RNAi. Upon complex formation with small non-coding RNAs, the protein initially interacts with the 5′-end of a given guide RNA through multiple interactions within the MID domain. This interaction has been reported to show a strong bias for U and A over C and G at the 5′-position. Performing molecular dynamics simulations of binary hAgo2/OH–guide–RNA complexes, we show that hAgo2 is a highly flexible protein capable of binding to guide strands with all four possible 5′-bases. Especially, in the case of C and G this is associated with rather large individual conformational rearrangements affecting the MID, PAZ and even the N-terminal domains to different degrees. Moreover, a 5′-G induces domain motions in the protein, which trigger a previously unreported interaction between the 5′-base and the L2 linker domain. Combining our in silico analyses with biochemical studies of recombinant hAgo2, we find that, contrary to previous observations, hAgo2 is capable of functionally accommodating guide strands regardless of the 5′-base.

  8. Expression of human ARGONAUTE 2 inhibits endogenous microRNA activity in Arabidopsis

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    Ira eDeveson

    2013-04-01

    Full Text Available Plant and animal microRNA (miRNA pathways share many analogous components, the ARGONAUTE (AGO proteins being foremost among them. We sought to ascertain the degree of functional conservation shared by Homo sapiens ARGONAUTE 2 (HsAGO2 and Arabidopsis thaliana ARGONAUTE 1 (AtAGO1, which are the predominant AGO family members involved with miRNA activity in their respective species. Transgenic Arabidopsis plants expressing HsAGO2 were indistinguishable from counterparts over-expressing AtAGO1, each group exhibiting the morphological and molecular hallmarks of miRNA-pathway loss-of-function alleles. However, unlike AtAGO1, HsAGO2 was unable to rescue the ago1-27 allele. We conclude that, despite the evolutionary gulf between them, HsAGO2 is likely capable of interacting with some component/s of the Arabidopsis miRNA pathway, thereby perturbing its operation, although differences have arisen such that HsAGO2 alone is insufficient to confer efficient silencing of miRNA targets in planta.

  9. Bacterial Expression of Mouse Argonaute 2 for Functional and Mutational Studies

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    Aniello Russo

    2010-02-01

    Full Text Available RNA interference (RNAi is a post-transcriptional gene-silencing process that occurs in many eukaryotic organisms upon intracellular exposure to double-stranded RNA. Argonaute 2 (Ago2 protein is the catalytic engine of mammalian RNAi. It contains a PIWI domain that is structurally related to RNases H and possibly shares with them a two-metal-ion catalysis mechanism. Here we describe the expression in E. coli of mouse Ago2 and testing of its enzymatic activity in a RISC assay, i.e., for the ability to cleave a target RNA in a single position specified by a complementary small interfering RNA (siRNA. The results show that the enzyme can load the siRNA and cleave the complementary RNA in absence of other cellular factors, as described for human Ago2. It was also found that mutation of Arg669, a residue previously proposed to be involved in substrate and/or B metal ion binding, doesn’t affect the enzymatic activity, suggesting that this residue doesn’t belong to the active site.

  10. HIV-1 RNAs are Not Part of the Argonaute 2 Associated RNA Interference Pathway in Macrophages.

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    Valentina Vongrad

    Full Text Available MiRNAs and other small noncoding RNAs (sncRNAs are key players in post-transcriptional gene regulation. HIV-1 derived small noncoding RNAs (sncRNAs have been described in HIV-1 infected cells, but their biological functions still remain to be elucidated. Here, we approached the question whether viral sncRNAs may play a role in the RNA interference (RNAi pathway or whether viral mRNAs are targeted by cellular miRNAs in human monocyte derived macrophages (MDM.The incorporation of viral sncRNAs and/or their target RNAs into RNA-induced silencing complex was investigated using photoactivatable ribonucleoside-induced cross-linking and immunoprecipitation (PAR-CLIP as well as high-throughput sequencing of RNA isolated by cross-linking immunoprecipitation (HITS-CLIP, which capture Argonaute2-bound miRNAs and their target RNAs. HIV-1 infected monocyte-derived macrophages (MDM were chosen as target cells, as they have previously been shown to express HIV-1 sncRNAs. In addition, we applied small RNA deep sequencing to study differential cellular miRNA expression in HIV-1 infected versus non-infected MDMs.PAR-CLIP and HITS-CLIP data demonstrated the absence of HIV-1 RNAs in Ago2-RISC, although the presence of a multitude of HIV-1 sncRNAs in HIV-1 infected MDMs was confirmed by small RNA sequencing. Small RNA sequencing revealed that 1.4% of all sncRNAs were of HIV-1 origin. However, neither HIV-1 derived sncRNAs nor putative HIV-1 target sequences incorporated into Ago2-RISC were identified suggesting that HIV-1 sncRNAs are not involved in the canonical RNAi pathway nor is HIV-1 targeted by this pathway in HIV-1 infected macrophages.

  11. Argonaute 2 complexes selectively protect the circulating microRNAs in cell-secreted microvesicles.

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    Limin Li

    Full Text Available Cell-secreted miRNAs are highly stable and can serve as biomarkers for various diseases and signaling molecules in intercellular communication. The mechanism underlying the stability of circulating miRNAs, however, remains incompletely understood. Here we show that Argonaute 2 (Ago2 complexes and microvesicles (MVs provide specific and non-specific protection for miRNA in cell-secreted MVs, respectively. First, the resistance of MV-encapsulated miRNAs to RNaseA was both depended on intact vesicular structure of MVs and protease-sensitive. Second, an immunoprecipitation assay using a probe complementary to human miR-16, a miRNA primarily located in the MVs and showed a strong, protease-sensitive resistance to RNaseA, identified Ago2 as a major miR-16-associated protein. Compared with protein-free miR-16, Ago2-associated miR-16 was resistant to RNaseA in a dose- and time-dependent fashion. Third, when the miR-16/Ago2 complex was disrupted by trypaflavine, the resistance of miR-16 to RNaseA was decreased. In contrast, when the association of miR-16 with the Ago2 complexes was increased during cell apoptosis, although the total amount of miR-16 and Ago2 remained unchanged, the resistance of miR-16 to RNaseA in the MVs was enhanced. A similar correlation between the increase of miR-223/Ago2 association and the resistance of miR-223 against RNaseA was observed during all trans retinoic acid (ATRA-induced cell differentiation of promyelocytic HL60 cells. In conclusion, the association of miRNAs with Ago2 complexes, an event that is linked to cell functional status, plays a critical role in stabilizing the circulating miRNAs in cell-secreted MVs.

  12. Seizure Suppression by High Temperature via cAMP Modulation in Drosophila

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    Saras, Arunesh; Tanouye, Mark A.

    2016-01-01

    Bang-sensitive (BS) Drosophila mutants display characteristic seizure-like activity (SLA) and paralysis after mechanical shock . After high-frequency electrical stimulation (HFS) of the brain, they generate robust seizures at very low threshold voltage. Here we report an important phenomenon, which effectively suppresses SLA in BS mutants. High temperature causes seizure suppression in all BS mutants (parabss1, eas, sda) examined in this study. This effect is fully reversible and flies show complete recovery from BS paralysis once the temperature effect is nullified. High temperature induces an increase in seizure threshold after a brief pulse of heat shock (HS). By genetic screening, we identified the involvement of cAMP in the suppression of seizures by high temperature. We propose that HS induces adenylyl cyclase which in turn increases cAMP concentration which eventually suppresses seizures in mutant flies. In summary, we describe an unusual phenomenon, where high temperature can suppress SLA in flies by modulating cAMP concentration. PMID:27558668

  13. Mutations of the Calcium Channel Gene cacophony Suppress Seizures in Drosophila.

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    Arunesh Saras

    2016-01-01

    Full Text Available Bang sensitive (BS Drosophila mutants display characteristic seizure-like phenotypes resembling, in some aspects, those of human seizure disorders such as epilepsy. The BS mutant parabss1, caused by a gain-of-function mutation of the voltage-gated Na+ channel gene, is extremely seizure-sensitive with phenotypes that have proven difficult to ameliorate by anti-epileptic drug feeding or by seizure-suppressor mutation. It has been presented as a model for intractable human epilepsy. Here we show that cacophony (cacTS2, a mutation of the Drosophila presynaptic Ca++ channel α1 subunit gene, is a particularly potent seizure-suppressor mutation, reverting seizure-like phenotypes for parabss1 and other BS mutants. Seizure-like phenotypes for parabss1 may be suppressed by as much as 90% in double mutant combinations with cacTS2. Unexpectedly, we find that parabss1 also reciprocally suppresses cacTS2 seizure-like phenotypes. The cacTS2 mutant displays these seizure-like behaviors and spontaneous high-frequency action potential firing transiently after exposure to high temperature. We find that this seizure-like behavior in cacTS2 is ameliorated by 85% in double mutant combinations with parabss1.

  14. Notch maintains Drosophila type II neuroblasts by suppressing expression of the Fez transcription factor Earmuff.

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    Li, Xiaosu; Xie, Yonggang; Zhu, Sijun

    2016-07-15

    Notch signaling is crucial for maintaining neural stem cell (NSC) self-renewal and heterogeneity; however, the underlying mechanism is not well understood. In Drosophila, loss of Notch prematurely terminates the self-renewal of larval type II neuroblasts (NBs, the Drosophila NSCs) and transforms type II NBs into type I NBs. Here, we demonstrate that Notch maintains type II NBs by suppressing the activation of earmuff (erm) by Pointed P1 (PntP1). We show that loss of Notch or components of its canonical pathway leads to PntP1-dependent ectopic Erm expression in type II NBs. Knockdown of Erm significantly rescues the loss-of-Notch phenotypes, and misexpression of Erm phenocopies the loss of Notch. Ectopically expressed Erm promotes the transformation of type II NBs into type I NBs by inhibiting PntP1 function and expression in type II NBs. Our work not only elucidates a key mechanism of Notch-mediated maintenance of type II NB self-renewal and identity, but also reveals a novel function of Erm. PMID:27151950

  15. Argonaute-2 regulates the proliferation of adult stem cells in planarian

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    Yong-Qin Li; An Zeng; Xiao-Shuai Han; Chen Wang; Ge Li; Zhen-Chao Zhang; Jian-Yong Wang; Yong-Wen Qin; Qing Jing

    2011-01-01

    Dear Editor,Planarian Schmidtea mediterranea has extraordinary regeneration capabilities due to the abundance of adult stem cells (ASCs) known as neoblasts,which make planarian a powerful in vivo system to study ASC biology [ 1 ].The Argonaute (AGO) family proteins are defined by the presence of Piwi-Argonaute-Zwille (PAZ)) and PIWI domains [2],and mediate silencing via cleavage of mRNAs [3] or inhibition of translation [4].The AGO family proteins fall into two subfamilies,one named after Arabidopsis Argonaute and the other after Drosophila PIWI [5].In most organisms investigated so far,PIWI proteins bind Piwi-interacting RNAs (piRNAs) and are functionally involved in the regulation of germ cells [6,7].By contrast,AGO proteins have distinct roles in the smallRNA-mediated gene silencing pathway.In Drosophila,AGO1 has been illustrated to be engaged in the miRNA pathway,while AGO2 plays an important role in the siRNA-mediated gene regulation [4].

  16. Argonaute 2 in cell-secreted microvesicles guides the function of secreted miRNAs in recipient cells.

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    Zhiyuan Lv

    Full Text Available MicroRNAs (miRNAs secreted by cells into microvesicles (MVs form a novel class of signal molecules that mediate intercellular communication. However, several fundamental aspects of secreted miRNAs remain unknown, particularly the mechanism that governs the function or fate of exogenous miRNAs in recipient cells. In the present study, we provide evidence indicating that Argonaute 2 (Ago2 plays a role in stabilizing miRNAs and facilitating the packaging of secreted miRNAs into MVs. More importantly, Ago2 in origin cell-secreted MVs (but not in recipient cells directs the function of secreted miRNAs. First, Ago2 overexpression clearly increased the level of miR-16 in cells transfected with a miR-16 mimic by protecting the miRNAs from degradation in lysosomes. Second, Ago2 overexpression increased the level of miR-16 in cell-secreted MVs, suggesting that Ago2 may facilitate the packaging of secreted miRNAs into MVs. Third, exogenous miR-16 delivered by MVs within the origin cells significantly reduced the Bcl2 protein level in recipient cells, and miR-16 and Bcl2 mRNA were physically associated with exogenous HA-tagged Ago2 (HA-Ago2. Finally, the effect of MV-delivered miR-16 on the production of the Bcl2 protein in recipient cells was not abolished by knocking down Ago2 in the recipient cells.

  17. Argonaute2 Protein in Rat Spermatogenic Cells Is Localized to Nuage Structures and LAMP2-Positive Vesicles Surrounding Chromatoid Bodies.

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    Fujii, Yuki; Onohara, Yuko; Fujita, Hideaki; Yokota, Sadaki

    2016-04-01

    Localization of Argonaute2 (AGO2) protein--an essential component for the processing of small interfering RNA (siRNA)-directed RNA interference (RNAi) in RNA-induced silencing complex (RISC) in nuage of rat spermatogenic cells--was evaluated by immunofluorescence microscopy (IFM) and immunoelectron microscopy (IEM). AGO2 was shown, for the first time, to be localized to four previously classified types of nuage: irregularly shaped perinuclear granules (ISPGs), intermitochondrial cement (IMC), satellite bodies (SBs), and chromatoid bodies (CBs). Dual IEM staining for AGO2/Maelstrom (MAEL) protein or AGO2/MIWI protein demonstrated that AGO2 is colocalized with MAEL or MIWI proteins in these types of nuage. Dual IFM and IEM staining of AGO2/lysosomal-associated membrane protein 2 (LAMP2) showed that CB in round spermatids are in contact with and surrounded by LAMP2-positive vesicles, whereas nuage in pachytene spermatocytes are not. Taken together, our findings indicate that: (i) AGO2 in pachytene spermatocytes functions in ISPGs, IMC, and SBs; (ii) AGO2 in round spermatids functions in CBs, and that CBs are associated with lysosomal compartments. PMID:27029769

  18. Drosophila clueless is highly expressed in larval neuroblasts, affects mitochondrial localization and suppresses mitochondrial oxidative damage.

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    Aditya Sen

    Full Text Available Mitochondria are critical for neuronal function due to the high demand of ATP in these cell types. During Drosophila development, neuroblasts in the larval brain divide asymmetrically to populate the adult central nervous system. While many of the proteins responsible for maintaining neuroblast cell fate and asymmetric cell divisions are known, little is know about the role of metabolism and mitochondria in neuroblast division and maintenance. The gene clueless (clu has been previously shown to be important for mitochondrial function. clu mutant adults have severely shortened lifespans and are highly uncoordinated. Part of their lack of coordination is due to defects in muscle, however, in this study we have identified high levels of Clu expression in larval neuroblasts and other regions of the dividing larval brain. We show while mitochondria in clu mutant neuroblasts are mislocalized during the cell cycle, surprisingly, overall brain morphology appears to be normal. This is explained by our observation that clu mutant larvae have normal levels of ATP and do not suffer oxidative damage, in sharp contrast to clu mutant adults. Mutations in two other genes encoding mitochondrial proteins, technical knockout and stress sensitive B, do not cause neuroblast mitochondrial mislocalization, even though technical knockout mutant larvae suffer oxidative damage. These results suggest Clu functions upstream of electron transport and oxidative phosphorylation, has a role in suppressing oxidative damage in the cell, and that lack of Clu's specific function causes mitochondria to mislocalize. These results also support the previous observation that larval development relies on aerobic glycolysis, rather than oxidative phosphorylation. Thus Clu's role in mitochondrial function is not critical during larval development, but is important for pupae and adults.

  19. The Mosquito Repellent Citronellal Directly Potentiates Drosophila TRPA1, Facilitating Feeding Suppression

    OpenAIRE

    Du, Eun Jo; Ahn, Tae Jung; Choi, Min Sung; Kwon, Ilmin; Kim, Hyung-Wook; Kwon, Jae Young; Kang, KyeongJin

    2015-01-01

    Citronellal, a well-known plant-derived mosquito repellent, was previously reported to repel Drosophila melanogaster via olfactory pathways involving but not directly activating Transient Receptor Potential Ankyrin 1 (TRPA1). Here, we show that citronellal is a direct agonist for Drosophila and human TRPA1s (dTRPA1 and hTRPA1) as well as Anopheles gambiae TRPA1 (agTRPA1). Citronellal-induced activity is isoform-dependent for Drosophila and Anopheles gambiae TRPA1s. The recently identified dTR...

  20. p8/TTDA overexpression enhances UV-irradiation resistance and suppresses TFIIH mutations in a Drosophila trichothiodystrophy model.

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    Javier Aguilar-Fuentes

    2008-11-01

    Full Text Available Mutations in certain subunits of the DNA repair/transcription factor complex TFIIH are linked to the human syndromes xeroderma pigmentosum (XP, Cockayne's syndrome (CS, and trichothiodystrophy (TTD. One of these subunits, p8/TTDA, interacts with p52 and XPD and is important in maintaining TFIIH stability. Drosophila mutants in the p52 (Dmp52 subunit exhibit phenotypic defects similar to those observed in TTD patients with defects in p8/TTDA and XPD, including reduced levels of TFIIH. Here, we demonstrate that several Dmp52 phenotypes, including lethality, developmental defects, and sterility, can be suppressed by p8/TTDA overexpression. TFIIH levels were also recovered in rescued flies. In addition, p8/TTDA overexpression suppressed a lethal allele of the Drosophila XPB homolog. Furthermore, transgenic flies overexpressing p8/TTDA were more resistant to UV irradiation than were wild-type flies, apparently because of enhanced efficiency of cyclobutane-pyrimidine-dimers and 6-4 pyrimidine-pyrimidone photoproducts repair. This study is the first using an intact higher-animal model to show that one subunit mutant can trans-complement another subunit in a multi-subunit complex linked to human diseases.

  1. The Mosquito Repellent Citronellal Directly Potentiates Drosophila TRPA1, Facilitating Feeding Suppression.

    Science.gov (United States)

    Du, Eun Jo; Ahn, Tae Jung; Choi, Min Sung; Kwon, Ilmin; Kim, Hyung-Wook; Kwon, Jae Young; Kang, KyeongJin

    2015-10-01

    Citronellal, a well-known plant-derived mosquito repellent, was previously reported to repel Drosophila melanogaster via olfactory pathways involving but not directly activating Transient Receptor Potential Ankyrin 1 (TRPA1). Here, we show that citronellal is a direct agonist for Drosophila and human TRPA1s (dTRPA1 and hTRPA1) as well as Anopheles gambiae TRPA1 (agTRPA1). Citronellal-induced activity is isoform-dependent for Drosophila and Anopheles gambiae TRPA1s. The recently identified dTRPA1(A) and ag-TRPA1(A) isoforms showed citronellal-provoked currents with EC50s of 1.0 B1 0.2 and 0.1 B1 0.03 mM, respectively, in Xenopus oocytes, while the sensitivities of TRPA1(B)s were much inferior to those of TRPA1(A)s. Citronellal dramatically enhanced the feeding-inhibitory effect of the TRPA1 agonist N-methylmaleimide (NMM) in Drosophila at an NMM concentration that barely repels flies. Thus, citronellal can promote feeding deterrence of fruit flies through direct action on gustatory dTRPA1, revealing the first isoform-specific function for TRPA1(A). PMID:26447139

  2. The deubiquitinating enzyme DUBAI stabilizes DIAP1 to suppress Drosophila apoptosis.

    Science.gov (United States)

    Yang, C-S; Sinenko, S A; Thomenius, M J; Robeson, A C; Freel, C D; Horn, S R; Kornbluth, S

    2014-04-01

    Deubiquitinating enzymes (DUBs) counteract ubiquitin ligases to modulate the ubiquitination and stability of target signaling molecules. In Drosophila, the ubiquitin-proteasome system has a key role in the regulation of apoptosis, most notably, by controlling the abundance of the central apoptotic regulator DIAP1. Although the mechanism underlying DIAP1 ubiquitination has been extensively studied, the precise role of DUB(s) in controlling DIAP1 activity has not been fully investigated. Here we report the identification of a DIAP1-directed DUB using two complementary approaches. First, a panel of putative Drosophila DUBs was expressed in S2 cells to determine whether DIAP1 could be stabilized, despite treatment with death-inducing stimuli that would induce DIAP1 degradation. In addition, RNAi fly lines were used to detect modifiers of DIAP1 antagonist-induced cell death in the developing eye. Together, these approaches identified a previously uncharacterized protein encoded by CG8830, which we named DeUBiquitinating-Apoptotic-Inhibitor (DUBAI), as a novel DUB capable of preserving DIAP1 to dampen Drosophila apoptosis. DUBAI interacts with DIAP1 in S2 cells, and the putative active site of its DUB domain (C367) is required to rescue DIAP1 levels following apoptotic stimuli. DUBAI, therefore, represents a novel locus of apoptotic regulation in Drosophila, antagonizing cell death signals that would otherwise result in DIAP1 degradation.

  3. Ebi/AP-1 suppresses pro-apoptotic genes expression and permits long-term survival of Drosophila sensory neurons.

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    Young-Mi Lim

    Full Text Available Sensory organs are constantly exposed to physical and chemical stresses that collectively threaten the survival of sensory neurons. Failure to protect stressed neurons leads to age-related loss of neurons and sensory dysfunction in organs in which the supply of new sensory neurons is limited, such as the human auditory system. Transducin β-like protein 1 (TBL1 is a candidate gene for ocular albinism with late-onset sensorineural deafness, a form of X-linked age-related hearing loss. TBL1 encodes an evolutionarily conserved F-box-like and WD40 repeats-containing subunit of the nuclear receptor co-repressor/silencing mediator for retinoid and thyroid hormone receptor and other transcriptional co-repressor complexes. Here we report that a Drosophila homologue of TBL1, Ebi, is required for maintenance of photoreceptor neurons. Loss of ebi function caused late-onset neuronal apoptosis in the retina and increased sensitivity to oxidative stress. Ebi formed a complex with activator protein 1 (AP-1 and was required for repression of Drosophila pro-apoptotic and anti-apoptotic genes expression. These results suggest that Ebi/AP-1 suppresses basal transcription levels of apoptotic genes and thereby protects sensory neurons from degeneration.

  4. Hsp104 suppresses polyglutamine-induced degeneration post onset in a drosophila MJD/SCA3 model.

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    Mimi Cushman-Nick

    Full Text Available There are no effective therapeutics that antagonize or reverse the protein-misfolding events underpinning polyglutamine (PolyQ disorders, including Spinocerebellar Ataxia Type-3 (SCA3. Here, we augment the proteostasis network of Drosophila SCA3 models with Hsp104, a powerful protein disaggregase from yeast, which is bafflingly absent from metazoa. Hsp104 suppressed eye degeneration caused by a C-terminal ataxin-3 (MJD fragment containing the pathogenic expanded PolyQ tract, but unexpectedly enhanced aggregation and toxicity of full-length pathogenic MJD. Hsp104 suppressed toxicity of MJD variants lacking a portion of the N-terminal deubiquitylase domain and full-length MJD variants unable to engage polyubiquitin, indicating that MJD-ubiquitin interactions hinder protective Hsp104 modalities. Importantly, in staging experiments, Hsp104 suppressed toxicity of a C-terminal MJD fragment when expressed after the onset of PolyQ-induced degeneration, whereas Hsp70 was ineffective. Thus, we establish the first disaggregase or chaperone treatment administered after the onset of pathogenic protein-induced degeneration that mitigates disease progression.

  5. Drosophila cyfip regulates synaptic development and endocytosis by suppressing filamentous actin assembly.

    Science.gov (United States)

    Zhao, Lu; Wang, Dan; Wang, Qifu; Rodal, Avital A; Zhang, Yong Q

    2013-04-01

    The formation of synapses and the proper construction of neural circuits depend on signaling pathways that regulate cytoskeletal structure and dynamics. After the mutual recognition of a growing axon and its target, multiple signaling pathways are activated that regulate cytoskeletal dynamics to determine the morphology and strength of the connection. By analyzing Drosophila mutations in the cytoplasmic FMRP interacting protein Cyfip, we demonstrate that this component of the WAVE complex inhibits the assembly of filamentous actin (F-actin) and thereby regulates key aspects of synaptogenesis. Cyfip regulates the distribution of F-actin filaments in presynaptic neuromuscular junction (NMJ) terminals. At cyfip mutant NMJs, F-actin assembly was accelerated, resulting in shorter NMJs, more numerous satellite boutons, and reduced quantal content. Increased synaptic vesicle size and failure to maintain excitatory junctional potential amplitudes under high-frequency stimulation in cyfip mutants indicated an endocytic defect. cyfip mutants exhibited upregulated bone morphogenetic protein (BMP) signaling, a major growth-promoting pathway known to be attenuated by endocytosis at the Drosophila NMJ. We propose that Cyfip regulates synapse development and endocytosis by inhibiting actin assembly.

  6. A suppression hierarchy among competing motor programs drives sequential grooming in Drosophila.

    Science.gov (United States)

    Seeds, Andrew M; Ravbar, Primoz; Chung, Phuong; Hampel, Stefanie; Midgley, Frank M; Mensh, Brett D; Simpson, Julie H

    2014-08-19

    Motor sequences are formed through the serial execution of different movements, but how nervous systems implement this process remains largely unknown. We determined the organizational principles governing how dirty fruit flies groom their bodies with sequential movements. Using genetically targeted activation of neural subsets, we drove distinct motor programs that clean individual body parts. This enabled competition experiments revealing that the motor programs are organized into a suppression hierarchy; motor programs that occur first suppress those that occur later. Cleaning one body part reduces the sensory drive to its motor program, which relieves suppression of the next movement, allowing the grooming sequence to progress down the hierarchy. A model featuring independently evoked cleaning movements activated in parallel, but selected serially through hierarchical suppression, was successful in reproducing the grooming sequence. This provides the first example of an innate motor sequence implemented by the prevailing model for generating human action sequences.

  7. Suppression of induced but not developmental apoptosis in Drosophila by Ayurvedic Amalaki Rasayana and Rasa-Sindoor

    Indian Academy of Sciences (India)

    Vibha Dwivedi; Shweta Tiwary; Subhash C Lakhotia

    2015-06-01

    Earlier we showed formulation-specific beneficial effects of dietary supplement of Ayurvedic Amalaki Rasayana (AR, a herbal formulation) and Rasa-Sindoor (RS, a mercury-based organo-metallic formulation) on various biological parameters in Drosophila, parallel to traditional Ayurvedic literature. These formulations also suppressed cell death and pathology in fly models of neurodegeneration. To understand basis of inhibition of apoptosis, we examined effects of AR and RS on induced and developmental apoptosis in Drosophila. Dietary AR or RS significantly reduced apoptosis induced by GMR-GAL4-, sev-GAL4- or hs-GAL4-directed expression of Rpr, Hid or Grim (RHG) pro-apoptotic proteins or by GMR-GAL4-directed DIAP1-RNAi, resulting in significant restoration of organism's viability and eye morphology. AR or RS supplement enhanced levels of inhibitor of apoptosis proteins, DIAP1 and DIAP2, and of Bancal/Hrb57A, while the levels of RHG proteins and of initiator Dronc and effecter Drice caspases were reduced in non-apoptotic wild type as well as in RHG over-expressing tissues. Levels of Dronc or Drice remained unaffected in cells developmentally destined to die so that developmental apoptosis occurred normally. Elevated levels of DIAPs and reduced levels of RHG proteins and caspases reflect a more robust physiological state of AR or RS fed organisms allowing them to tolerate greater insults without triggering the cell-death response. Such homeo-static effects of these Rasayanas seem to contribute to ‘healthy ageing’, one of their effects suggested in traditional Ayurvedic practices.

  8. Metal Homeostasis Regulators Suppress FRDA Phenotypes in a Drosophila Model of the Disease

    Science.gov (United States)

    Soriano, Sirena; Calap-Quintana, Pablo; Llorens, José Vicente; Al-Ramahi, Ismael; Gutiérrez, Lucía; Martínez-Sebastián, María José; Botas, Juan; Moltó, María Dolores

    2016-01-01

    Friedreich’s ataxia (FRDA), the most commonly inherited ataxia in populations of European origin, is a neurodegenerative disorder caused by a decrease in frataxin levels. One of the hallmarks of the disease is the accumulation of iron in several tissues including the brain, and frataxin has been proposed to play a key role in iron homeostasis. We found that the levels of zinc, copper, manganese and aluminum were also increased in a Drosophila model of FRDA, and that copper and zinc chelation improve their impaired motor performance. By means of a candidate genetic screen, we identified that genes implicated in iron, zinc and copper transport and metal detoxification can restore frataxin deficiency-induced phenotypes. Taken together, these results demonstrate that the metal dysregulation in FRDA includes other metals besides iron, therefore providing a new set of potential therapeutic targets. PMID:27433942

  9. Metal Homeostasis Regulators Suppress FRDA Phenotypes in a Drosophila Model of the Disease.

    Directory of Open Access Journals (Sweden)

    Sirena Soriano

    Full Text Available Friedreich's ataxia (FRDA, the most commonly inherited ataxia in populations of European origin, is a neurodegenerative disorder caused by a decrease in frataxin levels. One of the hallmarks of the disease is the accumulation of iron in several tissues including the brain, and frataxin has been proposed to play a key role in iron homeostasis. We found that the levels of zinc, copper, manganese and aluminum were also increased in a Drosophila model of FRDA, and that copper and zinc chelation improve their impaired motor performance. By means of a candidate genetic screen, we identified that genes implicated in iron, zinc and copper transport and metal detoxification can restore frataxin deficiency-induced phenotypes. Taken together, these results demonstrate that the metal dysregulation in FRDA includes other metals besides iron, therefore providing a new set of potential therapeutic targets.

  10. Sumoylation is tumor-suppressive and confers proliferative quiescence to hematopoietic progenitors in Drosophila melanogaster larvae

    Directory of Open Access Journals (Sweden)

    Marta E. Kalamarz

    2011-12-01

    How cell-intrinsic regulation of the cell cycle and the extrinsic influence of the niche converge to provide proliferative quiescence, safeguard tissue integrity, and provide avenues to stop stem cells from giving rise to tumors is a major challenge in gene therapy and tissue engineering. We explore this question in sumoylation-deficient mutants of Drosophila. In wild type third instar larval lymph glands, a group of hematopoietic stem/progenitor cells acquires quiescence; a multicellular niche supports their undifferentiated state. However, how proliferative quiescence is instilled in this population is not understood. We show that Ubc9 protein is nuclear in this population. Loss of the SUMO-activating E1 enzyme, Aos1/Uba2, the conjugating E2 enzyme, Ubc9, or the E3 SUMO ligase, PIAS, results in a failure of progenitors to quiesce; progenitors become hyperplastic, misdifferentiate, and develop into microtumors that eventually detach from the dorsal vessel. Significantly, dysplasia and lethality of Ubc9 mutants are rescued when Ubc9wt is provided specifically in the progenitor populations, but not when it is provided in the niche or in the differentiated cortex. While normal progenitors express high levels of the Drosophila cyclin-dependent kinase inhibitor p21 homolog, Dacapo, the corresponding overgrown mutant population exhibits a marked reduction in Dacapo. Forced expression of either Dacapo or human p21 in progenitors shrinks this population. The selective expression of either protein in mutant progenitor cells, but not in other hematopoietic populations, limits overgrowth, blocks tumorogenesis, and restores organ integrity. We discuss an essential and complex role for sumoylation in preserving the hematopoietic progenitor states for stress response and in the context of normal development of the fly.

  11. Drosophila cells use nanotube-like structures to transfer dsRNA and RNAi machinery between cells

    Science.gov (United States)

    Karlikow, Margot; Goic, Bertsy; Mongelli, Vanesa; Salles, Audrey; Schmitt, Christine; Bonne, Isabelle; Zurzolo, Chiara; Saleh, Maria-Carla

    2016-01-01

    Tunnelling nanotubes and cytonemes function as highways for the transport of organelles, cytosolic and membrane-bound molecules, and pathogens between cells. During viral infection in the model organism Drosophila melanogaster, a systemic RNAi antiviral response is established presumably through the transport of a silencing signal from one cell to another via an unknown mechanism. Because of their role in cell-cell communication, we investigated whether nanotube-like structures could be a mediator of the silencing signal. Here, we describe for the first time in the context of a viral infection the presence of nanotube-like structures in different Drosophila cell types. These tubules, made of actin and tubulin, were associated with components of the RNAi machinery, including Argonaute 2, double-stranded RNA, and CG4572. Moreover, they were more abundant during viral, but not bacterial, infection. Super resolution structured illumination microscopy showed that Argonaute 2 and tubulin reside inside the tubules. We propose that nanotube-like structures are one of the mechanisms by which Argonaute 2, as part of the antiviral RNAi machinery, is transported between infected and non-infected cells to trigger systemic antiviral immunity in Drosophila. PMID:27255932

  12. Selection of motor programs for suppressing food intake and inducing locomotion in the Drosophila brain.

    Science.gov (United States)

    Schoofs, Andreas; Hückesfeld, Sebastian; Schlegel, Philipp; Miroschnikow, Anton; Peters, Marc; Zeymer, Malou; Spieß, Roland; Chiang, Ann-Shyn; Pankratz, Michael J

    2014-06-01

    Central mechanisms by which specific motor programs are selected to achieve meaningful behaviors are not well understood. Using electrophysiological recordings from pharyngeal nerves upon central activation of neurotransmitter-expressing cells, we show that distinct neuronal ensembles can regulate different feeding motor programs. In behavioral and electrophysiological experiments, activation of 20 neurons in the brain expressing the neuropeptide hugin, a homolog of mammalian neuromedin U, simultaneously suppressed the motor program for food intake while inducing the motor program for locomotion. Decreasing hugin neuropeptide levels in the neurons by RNAi prevented this action. Reducing the level of hugin neuronal activity alone did not have any effect on feeding or locomotion motor programs. Furthermore, use of promoter-specific constructs that labeled subsets of hugin neurons demonstrated that initiation of locomotion can be separated from modulation of its motor pattern. These results provide insights into a neural mechanism of how opposing motor programs can be selected in order to coordinate feeding and locomotive behaviors. PMID:24960360

  13. Selection of motor programs for suppressing food intake and inducing locomotion in the Drosophila brain.

    Directory of Open Access Journals (Sweden)

    Andreas Schoofs

    2014-06-01

    Full Text Available Central mechanisms by which specific motor programs are selected to achieve meaningful behaviors are not well understood. Using electrophysiological recordings from pharyngeal nerves upon central activation of neurotransmitter-expressing cells, we show that distinct neuronal ensembles can regulate different feeding motor programs. In behavioral and electrophysiological experiments, activation of 20 neurons in the brain expressing the neuropeptide hugin, a homolog of mammalian neuromedin U, simultaneously suppressed the motor program for food intake while inducing the motor program for locomotion. Decreasing hugin neuropeptide levels in the neurons by RNAi prevented this action. Reducing the level of hugin neuronal activity alone did not have any effect on feeding or locomotion motor programs. Furthermore, use of promoter-specific constructs that labeled subsets of hugin neurons demonstrated that initiation of locomotion can be separated from modulation of its motor pattern. These results provide insights into a neural mechanism of how opposing motor programs can be selected in order to coordinate feeding and locomotive behaviors.

  14. RNA-Interference Components Are Dispensable for Transcriptional Silencing of the Drosophila Bithorax-Complex

    KAUST Repository

    Cernilogar, Filippo M.

    2013-06-13

    Background:Beyond their role in post-transcriptional gene silencing, Dicer and Argonaute, two components of the RNA interference (RNAi) machinery, were shown to be involved in epigenetic regulation of centromeric heterochromatin and transcriptional gene silencing. In particular, RNAi mechanisms appear to play a role in repeat induced silencing and some aspects of Polycomb-mediated gene silencing. However, the functional interplay of RNAi mechanisms and Polycomb group (PcG) pathways at endogenous loci remains to be elucidated.Principal Findings:Here we show that the endogenous Dicer-2/Argonaute-2 RNAi pathway is dispensable for the PcG mediated silencing of the homeotic Bithorax Complex (BX-C). Although Dicer-2 depletion triggers mild transcriptional activation at Polycomb Response Elements (PREs), this does not induce transcriptional changes at PcG-repressed genes. Moreover, Dicer-2 is not needed to maintain global levels of methylation of lysine 27 of histone H3 and does not affect PRE-mediated higher order chromatin structures within the BX-C. Finally bioinformatic analysis, comparing published data sets of PcG targets with Argonaute-2-bound small RNAs reveals no enrichment of these small RNAs at promoter regions associated with PcG proteins.Conclusions:We conclude that the Dicer-2/Argonaute-2 RNAi pathway, despite its role in pairing sensitive gene silencing of transgenes, does not have a role in PcG dependent silencing of major homeotic gene cluster loci in Drosophila. © 2013 Cernilogar et al.

  15. Assessing a peptidylic inhibitor-based therapeutic approach that simultaneously suppresses polyglutamine RNA- and protein-mediated toxicities in patient cells and Drosophila

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2016-03-01

    Full Text Available Polyglutamine (polyQ diseases represent a group of progressive neurodegenerative disorders that are caused by abnormal expansion of CAG triplet nucleotides in disease genes. Recent evidence indicates that not only mutant polyQ proteins, but also their corresponding mutant RNAs, contribute to the pathogenesis of polyQ diseases. Here, we describe the identification of a 13-amino-acid peptide, P3, which binds directly and preferentially to long-CAG RNA within the pathogenic range. When administered to cell and Drosophila disease models, as well as to patient-derived fibroblasts, P3 inhibited expanded-CAG-RNA-induced nucleolar stress and suppressed neurotoxicity. We further examined the combined therapeutic effect of P3 and polyQ-binding peptide 1 (QBP1, a well-characterized polyQ protein toxicity inhibitor, on neurodegeneration. When P3 and QBP1 were co-administered to disease models, both RNA and protein toxicities were effectively mitigated, resulting in a notable improvement of neurotoxicity suppression compared with the P3 and QBP1 single-treatment controls. Our findings indicate that targeting toxic RNAs and/or simultaneous targeting of toxic RNAs and their corresponding proteins could open up a new therapeutic strategy for treating polyQ degeneration.

  16. Drosophila ref(2)P is required for the parkin-mediated suppression of mitochondrial dysfunction in pink1 mutants.

    Science.gov (United States)

    de Castro, I P; Costa, A C; Celardo, I; Tufi, R; Dinsdale, D; Loh, S H Y; Martins, L M

    2013-10-24

    Autophagy is a critical regulator of organellar homeostasis, particularly of mitochondria. Upon the loss of membrane potential, dysfunctional mitochondria are selectively removed by autophagy through recruitment of the E3 ligase Parkin by the PTEN-induced kinase 1 (PINK1) and subsequent ubiquitination of mitochondrial membrane proteins. Mammalian sequestrome-1 (p62/SQSTM1) is an autophagy adaptor, which has been proposed to shuttle ubiquitinated cargo for autophagic degradation downstream of Parkin. Here, we show that loss of ref(2)P, the Drosophila orthologue of mammalian P62, results in abnormalities, including mitochondrial defects and an accumulation of mitochondrial DNA with heteroplasmic mutations, correlated with locomotor defects. Furthermore, we show that expression of Ref(2)P is able to ameliorate the defects caused by loss of Pink1 and that this depends on the presence of functional Parkin. Finally, we show that both the PB1 and UBA domains of Ref(2)P are crucial for mitochondrial clustering. We conclude that Ref(2)P is a crucial downstream effector of a pathway involving Pink1 and Parkin and is responsible for the maintenance of a viable pool of cellular mitochondria by promoting their aggregation and autophagic clearance.

  17. The endo-siRNA pathway is essential for robust development of the Drosophila embryo.

    Directory of Open Access Journals (Sweden)

    Elena M Lucchetta

    Full Text Available BACKGROUND: Robustness to natural temperature fluctuations is critical to proper development in embryos and to cellular functions in adult organisms. However, mechanisms and pathways which govern temperature compensation remain largely unknown beyond circadian rhythms. Pathways which ensure robustness against temperature fluctuations may appear to be nonessential under favorable, uniform environmental conditions used in conventional laboratory experiments where there is little variation for which to compensate. The endo-siRNA pathway, which produces small double-stranded RNAs in Drosophila, appears to be nonessential for robust development of the embryo under ambient uniform temperature and to be necessary only for viral defense. Embryos lacking a functional endo-siRNA pathway develop into phenotypically normal adults. However, we hypothesized that small RNAs may regulate the embryo's response to temperature, as a ribonucleoprotein complex has been previously shown to mediate mammalian cell response to heat shock. PRINCIPAL FINDINGS: Here, we show that the genes DICER-2 and ARGONAUTE2, which code for integral protein components of the endo-siRNA pathway, are essential for robust development and temperature compensation in the Drosophila embryo when exposed to temperature perturbations. The regulatory functions of DICER-2 and ARGONAUTE2 were uncovered by using microfluidics to expose developing Drosophila embryos to a temperature step, in which each half of the embryo develops at a different temperature through developmental cycle 14. Under this temperature perturbation, dicer-2 or argonaute2 embryos displayed abnormal segmentation. The abnormalities in segmentation are presumably due to the inability of the embryo to compensate for temperature-induced differences in rate of development and to coordinate developmental timing in the anterior and posterior halves. A deregulation of the length of nuclear division cycles 10-14 is also observed in

  18. Expression levels of the microRNA maturing microprocessor complex component DGCR8 and the RNA-induced silencing complex (RISC) components argonaute-1, argonaute-2, PACT, TARBP1, and TARBP2 in epithelial skin cancer.

    Science.gov (United States)

    Sand, Michael; Skrygan, Marina; Georgas, Dimitrios; Arenz, Christoph; Gambichler, Thilo; Sand, Daniel; Altmeyer, Peter; Bechara, Falk G

    2012-11-01

    The microprocessor complex mediates intranuclear biogenesis of precursor microRNAs from the primary microRNA transcript. Extranuclear, mature microRNAs are incorporated into the RNA-induced silencing complex (RISC) before interaction with complementary target mRNA leads to transcriptional repression or cleavage. In this study, we investigated the expression profiles of the microprocessor complex subunit DiGeorge syndrome critical region gene 8 (DGCR8) and the RISC components argonaute-1 (AGO1), argonaute-2 (AGO2), as well as double-stranded RNA-binding proteins PACT, TARBP1, and TARBP2 in epithelial skin cancer and its premalignant stage. Patients with premalignant actinic keratoses (AK, n = 6), basal cell carcinomas (BCC, n = 15), and squamous cell carcinomas (SCC, n = 7) were included in the study. Punch biopsies were harvested from the center of the tumors (lesional), from healthy skin sites (intraindividual controls), and from healthy skin sites in a healthy control group (n = 16; interindividual control). The DGCR8, AGO1, AGO2, PACT, TARBP1, and TARBP2 mRNA expression levels were detected by quantitative real-time reverse transcriptase polymerase chain reaction. The DGCR8, AGO1, AGO2, PACT, and TARBP1 expression levels were significantly higher in the AK, BCC, and SCC groups than the healthy controls (P  0.05). This study indicates that major components of the miRNA pathway, such as the microprocessor complex and RISC, are dysregulated in epithelial skin cancer.

  19. Mutant human torsinA, responsible for early-onset dystonia, dominantly suppresses GTPCH expression, dopamine levels and locomotion in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Noriko Wakabayashi-Ito

    2015-07-01

    Full Text Available Dystonia represents the third most common movement disorder in humans with over 20 genetic loci identified. TOR1A (DYT1, the gene responsible for the most common primary hereditary dystonia, encodes torsinA, an AAA ATPase family protein. Most cases of DYT1 dystonia are caused by a 3 bp (ΔGAG deletion that results in the loss of a glutamic acid residue (ΔE302/303 in the carboxyl terminal region of torsinA. This torsinAΔE mutant protein has been speculated to act in a dominant-negative manner to decrease activity of wild type torsinA. Drosophila melanogaster has a single torsin-related gene, dtorsin. Null mutants of dtorsin exhibited locomotion defects in third instar larvae. Levels of dopamine and GTP cyclohydrolase (GTPCH proteins were severely reduced in dtorsin-null brains. Further, the locomotion defect was rescued by the expression of human torsinA or feeding with dopamine. Here, we demonstrate that human torsinAΔE dominantly inhibited locomotion in larvae and adults when expressed in neurons using a pan-neuronal promoter Elav. Dopamine and tetrahydrobiopterin (BH4 levels were significantly reduced in larval brains and the expression level of GTPCH protein was severely impaired in adult and larval brains. When human torsinA and torsinAΔE were co-expressed in neurons in dtorsin-null larvae and adults, the locomotion rates and the expression levels of GTPCH protein were severely reduced. These results support the hypothesis that torsinAΔE inhibits wild type torsinA activity. Similarly, neuronal expression of a Drosophila DtorsinΔE equivalent mutation dominantly inhibited larval locomotion and GTPCH protein expression. These results indicate that both torsinAΔE and DtorsinΔE act in a dominant-negative manner. We also demonstrate that Dtorsin regulates GTPCH expression at the post-transcriptional level. This Drosophila model of DYT1 dystonia provides an important tool for studying the differences in the molecular function between the

  20. Drosophila myogenesis.

    Science.gov (United States)

    Bothe, Ingo; Baylies, Mary K

    2016-09-12

    The skeletal muscle system is the largest organ in motile animals, constituting between 35 and 55% of the human body mass, and up to 75% of the body mass in flying organisms like Drosophila. The flight muscles alone in flying insects comprise up to 65% of total body mass. Not only is the musculature the largest organ system, it is also exquisitely complex, with single muscles existing in different shapes and sizes. These different morphologies allow for such different functions as the high-frequency beating of a wing in a hummingbird, the dilation of the pupil in a human eye, or the maintenance of posture in a giraffe's neck. PMID:27623256

  1. Molecular Cloning of a Novel Bovine Homologue of the Drosophila Tumor Suppressor Gene, Lats

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Pervious studies demonstrate that lats, also known as warts, is a tumor suppressor gene in Drosophila[1,2]. Mutations of lats lead to an increase in cell number and organ size in Drosophila, indicating lats may be involved in organ size control. Furthermore, the high conservation of sequence and tumor suppression function of lats between Drosophila and human suggests that it may be also involved in organ size control of higher animals[3]. So here we isolated the bovine homologue of Drosophila lats. Sequence analysis indicates the bovine LATS1 to be very similar to other lats proteins.

  2. Drosophila egg chamber elongation

    OpenAIRE

    Gates, Julie

    2012-01-01

    As tissues and organs are formed, they acquire a specific shape that plays an integral role in their ability to function properly. A relatively simple system that has been used to examine how tissues and organs are shaped is the formation of an elongated Drosophila egg. While it has been known for some time that Drosophila egg elongation requires interactions between a polarized intracellular basal actin network and a polarized extracellular network of basal lamina proteins, how these interac...

  3. Suppression of Insulin Production and Secretion by a Decretin Hormone

    OpenAIRE

    Alfa, Ronald W.; Park, Sangbin; Skelly, Kathleen-Rose; Poffenberger, Gregory; Jain, Nimit; Gu, Xueying; Kockel, Lutz; Jing WANG; Liu, Yinghua; Powers, Alvin C.; Kim, Seung K.

    2015-01-01

    Decretins, hormones induced by fasting that suppress insulin production and secretion, have been postulated from classical human metabolic studies. From genetic screens, we identified Drosophila Limostatin (Lst), a peptide hormone that suppresses insulin secretion. Lst is induced by nutrient restriction in gut-associated endocrine cells. limostatin deficiency led to hyperinsulinemia, hypoglycemia and excess adiposity. A conserved 15-residue polypeptide encoded by limostatin suppressed secreti...

  4. Drosophila Porin/VDAC affects mitochondrial morphology.

    Directory of Open Access Journals (Sweden)

    Jeehye Park

    Full Text Available Voltage-dependent anion channel (VDAC has been suggested to be a mediator of mitochondrial-dependent cell death induced by Ca(2+ overload, oxidative stress and Bax-Bid activation. To confirm this hypothesis in vivo, we generated and characterized Drosophila VDAC (porin mutants and found that Porin is not required for mitochondrial apoptosis, which is consistent with the previous mouse studies. We also reported a novel physiological role of Porin. Loss of porin resulted in locomotive defects and male sterility. Intriguingly, porin mutants exhibited elongated mitochondria in indirect flight muscle, whereas Porin overexpression produced fragmented mitochondria. Through genetic analysis with the components of mitochondrial fission and fusion, we found that the elongated mitochondria phenotype in porin mutants were suppressed by increased mitochondrial fission, but enhanced by increased mitochondrial fusion. Furthermore, increased mitochondrial fission by Drp1 expression suppressed the flight defects in the porin mutants. Collectively, our study showed that loss of Drosophila Porin results in mitochondrial morphological defects and suggested that the defective mitochondrial function by Porin deficiency affects the mitochondrial remodeling process.

  5. Cancer in Drosophila

    DEFF Research Database (Denmark)

    Herranz, Héctor; Eichenlaub, Teresa; Cohen, Stephen M

    2016-01-01

    Cancer genomics has greatly increased our understanding of the complexity of the genetic and epigenetic changes found in human tumors. Understanding the functional relationships among these elements calls for the use of flexible genetic models. We discuss the use of Drosophila models to study...

  6. BMAA neurotoxicity in Drosophila.

    Science.gov (United States)

    Zhou, Xianchong; Escala, Wilfredo; Papapetropoulos, Spyridon; Bradley, Walter G; Zhai, R Grace

    2009-01-01

    We report the establishment of an in vivo model using the fruit fly Drosophila melanogaster to investigate the toxic effects of L-BMAA. We found that dietary intake of BMAA reduced the lifespan as well as the neurological functions of flies. Furthermore, we have developed an HPLC method to reliably detect both free and protein-bound BMAA in fly tissue extracts.

  7. Drosophila Conditioned Courtship: Two Ways of Testing Memory

    OpenAIRE

    Kamyshev, Nikolai G; Iliadi, Konstantin G.; Bragina, Julia V.

    1999-01-01

    In Drosophila, courtship reduction in male flies that have previous experience of courting a mated female is a result of the counterconditioning of an attractive unconditioned stimulus (US)—the aphrodisiac—which becomes an aversive conditioned stimulus (CS) after being paired with an aversive US—the antiaphrodisiac. In a retention test with a virgin female lacking the antiaphrodisiac, males retain a lower level of courtship for 3 hr after training. However, a measure of courtship suppression,...

  8. Drosophila by the dozen

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Olfactory learning in Drosophila

    OpenAIRE

    Nehrkorn, Johannes

    2016-01-01

    Animals are able to form associative memories and benefit from past experience. In classical conditioning an animal is trained to associate an initially neutral stimulus by pairing it with a stimulus that triggers an innate response. The neutral stimulus is commonly referred to as conditioned stimulus (CS) and the reinforcing stimulus as unconditioned stimulus (US). The underlying neuronal mechanisms and structures are an intensely investigated topic. The fruit fly Drosophila melanogaster...

  10. Drosophila as a genetically tractable model for social insect behaviour

    Directory of Open Access Journals (Sweden)

    Alison L Camiletti

    2016-04-01

    Full Text Available The relatively simple communication, breeding and egg-making systems that govern reproduction in female Drosophila retain homology to eusocial species in which these same systems are modified to the social condition. Despite having no parental care, division of labour or subfertile caste, Drosophila may nonetheless offer a living test of certain sociobiological hypotheses framed around gene function. In this review, we make this case, and do so around the recent discovery that the non-social fly, Drosophila melanogaster, can respond to the ovary-suppressing queen pheromone of the honey bee Apis meliffera. Here, we first explain the sociobiological imperative to reconcile kin theory with molecular biology, and qualify a potential role for Drosophila. Then, we offer three applications for the fly-pheromone assay. First, the availability and accessibility of massive mutant libraries makes immediately feasible any number of open or targeted gene screens against the ovary-inhibiting response. The sheer tractability of Drosophila may therefore help to accelerate the search for genes in pheromone-responsive pathways that regulate female reproduction, including potentially any that are preserved with modification to regulate worker sterility in response to queen pheromones in eusocial taxa. Secondly, Drosophila’s powerful Gal4/UAS expression system can complement the pheromone assay by driving target gene expression into living tissue, which could be well applied to the functional testing of genes presumed to drive ovary activation or de-activation in the honey bee or other eusocial taxa. Finally, coupling Gal4 with UAS-RNAi lines can facilitate loss-of-function experiments against perception and response to the ovary inhibiting pheromone, and do so for large numbers of candidates in systematic fashion. Drosophila's utility as an adjunct to the field of insect sociobiology is not ideal, but retains surprising potential.

  11. Selective Autophagy in Drosophila

    Directory of Open Access Journals (Sweden)

    Ioannis P. Nezis

    2012-01-01

    Full Text Available Autophagy is an evolutionarily conserved process of cellular self-eating and is a major pathway for degradation of cytoplasmic material by the lysosomal machinery. Autophagy functions as a cellular response in nutrient starvation, but it is also associated with the removal of protein aggregates and damaged organelles and therefore plays an important role in the quality control of proteins and organelles. Although it was initially believed that autophagy occurs randomly in the cell, during the last years, there is growing evidence that sequestration and degradation of cytoplasmic material by autophagy can be selective. Given the important role of autophagy and selective autophagy in several disease-related processes such as neurodegeneration, infections, and tumorigenesis, it is important to understand the molecular mechanisms of selective autophagy, especially at the organismal level. Drosophila is an excellent genetically modifiable model organism exhibiting high conservation in the autophagic machinery. However, the regulation and mechanisms of selective autophagy in Drosophila have been largely unexplored. In this paper, I will present an overview of the current knowledge about selective autophagy in Drosophila.

  12. Ion channels to inactivate neurons in Drosophila

    Directory of Open Access Journals (Sweden)

    James J L Hodge

    2009-08-01

    Full Text Available Ion channels are the determinants of excitability; therefore, manipulation of their levels and properties provides an opportunity for the investigator to modulate neuronal and circuit function. There are a number of ways to suppress electrical activity in Drosophila neurons, for instance, over-expression of potassium channels (i.e. Shaker Kv1, Shaw Kv3, Kir2.1 and DORK that are open at resting membrane potential. This will result in increased potassium efflux and membrane hyperpolarisation setting resting membrane potential below the threshold required to fire action potentials. Alternatively over-expression of other channels, pumps or co-transporters that result in a hyperpolarised membrane potential will also prevent firing. Lastly, neurons can be inactivated by, disrupting or reducing the level of functional voltage-gated sodium (Nav1 paralytic or calcium (Cav2 cacophony channels that mediate the depolarisation phase of action potentials. Similarly, strategies involving the opposite channel manipulation should allow net depolarisation and hyperexcitation in a given neuron. These changes in ion channel expression can be brought about by the versatile transgenic (i.e. Gal4/UAS based systems available in Drosophila allowing fine temporal and spatial control of (channel transgene expression. These systems are making it possible to electrically inactivate (or hyperexcite any neuron or neural circuit in the fly brain, and much like an exquisite lesion experiment, potentially elucidate whatever interesting behaviour or phenotype each network mediates. These techniques are now being used in Drosophila to reprogram electrical activity of well-defined circuits and bring about robust and easily quantifiable changes in behaviour, allowing different models and hypotheses to be rapidly tested.

  13. Lamin C and chromatin organization in Drosophila

    Indian Academy of Sciences (India)

    B. V. Gurudatta; L. S. Shashidhara; Veena K. Parnaik

    2010-04-01

    Drosophila lamin C (LamC) is a developmentally regulated component of the nuclear lamina. The lamC gene is situated in the fifth intron of the essential gene tout velu (ttv). We carried out genetic analysis of lamC during development. Phenotypic analyses of RNAi-mediated downregulation of lamC expression as well as targeted misexpression of lamin C suggest a role for lamC in cell survival. Of particular interest in the context of laminopathies is the caspase-dependent apoptosis induced by the overexpression of lamin C. Interestingly, misexpression of lamin C in the central nervous system, where it is not normally expressed, did not affect organization of the nuclear lamina. lamC mutant alleles suppressed position effect variegation normally displayed at near-centromeric and telomeric regions. Further, both downregulation and misexpression of lamin C affected the distribution of heterochromatin protein 1. Our results suggest that Drosophila lamC has a tissue-specific role during development and is required for chromatin organization.

  14. Drosophila bitter taste(s

    Directory of Open Access Journals (Sweden)

    Alice eFrench

    2015-11-01

    Full Text Available 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 the activation of 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 induce 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 inhibitory pheromones such as 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

  15. Quarkonium suppression

    Indian Academy of Sciences (India)

    P Petreczky

    2003-04-01

    I discuss quarkonium suppression in equilibrated strongly interacting matter. After a brief review of basic features of quarkonium production I discuss the application of recent lattice data on the heavy quark potential to the problem of quarkonium dissociation as well as the problem of direct lattice determination of quarkonium properties in finite temperature lattice QCD.

  16. Initial neurogenesis in Drosophila.

    Science.gov (United States)

    Hartenstein, Volker; Wodarz, Andreas

    2013-01-01

    Early neurogenesis comprises the phase of nervous system development during which neural progenitor cells are born. In early development, the embryonic ectoderm is subdivided by a conserved signaling mechanism into two main domains, the epidermal ectoderm and the neurectoderm. Subsequently, cells of the neurectoderm are internalized and form a cell layer of proliferating neural progenitors. In vertebrates, the entire neurectoderm folds into the embryo to give rise to the neural tube. In Drosophila and many other invertebrates, a subset of neurectodermal cells, called neuroblasts (NBs), delaminates and forms the neural primordium inside the embryo where they divide in an asymmetric, stem cell-like mode. The remainder of the neurectodermal cells that stay behind at the surface loose their neurogenic potential and later give rise to the ventral part of the epidermis. The genetic and molecular analysis of the mechanisms controlling specification and proliferation of NBs in the Drosophila embryo, which played a significant part in pioneering the field of modern developmental neurobiology, represents the topic of this review. PMID:24014455

  17. Sterol requirements in Drosophila melanogaster

    OpenAIRE

    Almeida de Carvalho, Maria Joao

    2009-01-01

    Sterol is an abundant component of eukaryotic cell membranes and is thought to influence membrane properties such as permeability, fluidity and microdomain formation. Drosophila is an excellent model system in which to study functional requirements for membrane sterol because, although it does not synthesize sterol, it nevertheless requires sterols to complete development. Moreover, Drosophila normally incorporates sterols into cell membranes. Thus, dietary sterol depletion can be used to ...

  18. Optogenetics in Drosophila Neuroscience.

    Science.gov (United States)

    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.

  19. Suppression of insulin production and secretion by a decretin hormone.

    Science.gov (United States)

    Alfa, Ronald W; Park, Sangbin; Skelly, Kathleen-Rose; Poffenberger, Gregory; Jain, Nimit; Gu, Xueying; Kockel, Lutz; Wang, Jing; Liu, Yinghua; Powers, Alvin C; Kim, Seung K

    2015-02-01

    Decretins, hormones induced by fasting that suppress insulin production and secretion, have been postulated from classical human metabolic studies. From genetic screens, we identified Drosophila Limostatin (Lst), a peptide hormone that suppresses insulin secretion. Lst is induced by nutrient restriction in gut-associated endocrine cells. limostatin deficiency led to hyperinsulinemia, hypoglycemia, and excess adiposity. A conserved 15-residue polypeptide encoded by limostatin suppressed secretion by insulin-producing cells. Targeted knockdown of CG9918, a Drosophila ortholog of Neuromedin U receptors (NMURs), in insulin-producing cells phenocopied limostatin deficiency and attenuated insulin suppression by purified Lst, suggesting CG9918 encodes an Lst receptor. NMUR1 is expressed in islet β cells, and purified NMU suppresses insulin secretion from human islets. A human mutant NMU variant that co-segregates with familial early-onset obesity and hyperinsulinemia fails to suppress insulin secretion. We propose Lst as an index member of an ancient hormone class called decretins, which suppress insulin output. PMID:25651184

  20. A Drosophila muscle-specific gene related to the mouse quaking locus.

    Science.gov (United States)

    Fyrberg, C; Becker, J; Barthmaier, P; Mahaffey, J; Fyrberg, E

    1997-09-15

    We have characterized a novel muscle-specific gene of Drosophila melanogaster, defined by enhancer trap strain 24B of Brand and Perrimon (1993). We show that transcripts of the gene accumulate within presumptive mesoderm and persist within developing muscles, strongly suggesting that the encoded protein is involved in muscle cell determination and differentiation. cDNA sequences reveal that the Drosophila protein is similar to quaking (64% identity over 210 amino acids), a protein essential for mouse embryogenesis, and gld-1 (53% identity over 162 amino acids) a germ-line-specific tumor suppressing protein of the nematode, Caenorhabditis elegans. We demonstrate that the Drosophila gene resides within the 93F chromosome subdivision, and describe its physical map. Finally, we have used the gene, which we have named quaking-related 93F (qkr93F), to identify a family of closely related KH domains. PMID:9332381

  1. Fan-shaped body neurons are involved in period-dependent regulation of long-term courtship memory in Drosophila

    OpenAIRE

    Sakai, Takaomi; Inami, Show; Sato, Shoma; Kitamoto, Toshihiro

    2012-01-01

    In addition to its established function in the regulation of circadian rhythms, the Drosophila gene period (per) also plays an important role in processing long-term memory (LTM). Here, we used courtship conditioning as a learning paradigm and revealed that (1) overexpression and knocking down of per in subsets of brain neurons enhance and suppress LTM, respectively, and (2) suppression of synaptic transmission during memory retrieval in the same neuronal subsets leads to defective LTM. Furth...

  2. Monitoring long-term evolutionary changes following Wolbachia introduction into a novel host: the Wolbachia popcorn infection in Drosophila simulans

    OpenAIRE

    Lauren B Carrington; Ary A Hoffmann; Weeks, Andrew R

    2010-01-01

    Wolbachia may act as a biological control agent for pest management; in particular, the Wolbachia variant wMelPop (popcorn) shortens host longevity and may be useful for dengue suppression. However, long-term changes in the host and Wolbachia genomes can alter Wolbachia spread and/or host effects that suppress disease. Here, we investigate the phenotypic effects of wMelPop in a non-native host, Drosophila simulans, following artificial transinfection approximately 200 generations ago. Long-te...

  3. Selectivity and plasticity in a sound-evoked male-male interaction in Drosophila.

    Directory of Open Access Journals (Sweden)

    Jeonghyeon Yoon

    Full Text Available During courtship, many animals, including insects, birds, fish, and mammals, utilize acoustic signals to transmit information about species identity. Although auditory communication is crucial across phyla, the neuronal and physiologic processes are poorly understood. Sound-evoked chaining behavior, a display of homosexual courtship behavior in Drosophila males, has long been used as an excellent model for analyzing auditory behavior responses, outcomes of acoustic perception and higher-order brain functions. Here we developed a new method, termed ChaIN (Chain Index Numerator, in which we use a computer-based auto detection system for chaining behavior. The ChaIN system can systematically detect the chaining behavior induced by a series of modified courtship song playbacks. Two evolutionarily related Drosophila species, Drosophila melanogaster and Drosophila simulans, exhibited dramatic selective increases in chaining behavior when exposed to specific auditory cues, suggesting that auditory discrimination processes are involved in the acceleration of chaining behavior. Prolonged monotonous pulse sounds containing courtship song components also induced high intense chaining behavior. Interestingly, the chaining behavior was gradually suppressed over time when song playback continued. This behavioral change is likely to be a plastic behavior and not a simple sensory adaptation or fatigue, because the suppression was released by applying a different pulse pattern. This behavioral plasticity is not a form of habituation because different modality stimuli did not recover the behavioral suppression. Intriguingly, this plastic behavior partially depended on the cAMP signaling pathway controlled by the rutabaga adenylyl cyclase gene that is important for learning and memory. Taken together, this study demonstrates the selectivity and behavioral kinetics of the sound-induced interacting behavior of Drosophila males, and provides a basis for the

  4. Iron Absorption in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Fanis Missirlis

    2013-05-01

    Full Text Available 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.

  5. Iron Absorption in Drosophila melanogaster

    Science.gov (United States)

    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

  6. Cholinergic Neurons Mediate CaMKII-Dependent Enhancement of Courtship Suppression

    Science.gov (United States)

    Mehren, Jennifer E.; Griffith, Leslie C.

    2006-01-01

    In "Drosophila," calcium/calmodulin-dependent protein kinase II (CaMKII) activity is crucial in associative courtship conditioning for both memory formation and suppression of courtship during training with a mated female. We have previously shown that increasing levels of constitutively active CaMKII, but not calcium-dependent CaMKII, in a subset…

  7. A directed mutagenesis screen in Drosophila melanogaster reveals new mutants that influence hedgehog signaling.

    OpenAIRE

    Haines, N; van den Heuvel, M

    2000-01-01

    The Hedgehog signaling pathway has been recognized as essential for patterning processes in development of metazoan animal species. The signaling pathway is, however, not entirely understood. To start to address this problem, we set out to isolate new mutations that influence Hedgehog signaling. We performed a mutagenesis screen for mutations that dominantly suppress Hedgehog overexpression phenotypes in the Drosophila melanogaster wing. We isolated four mutations that influence Hedgehog sign...

  8. Debra-Mediated Ci Degradation Controls Tissue Homeostasis in Drosophila Adult Midgut

    OpenAIRE

    Zhouhua Li; Yueqin Guo; Lili Han; Yan Zhang; Lai Shi; Xudong Huang; Xinhua Lin

    2014-01-01

    Summary Adult tissue homeostasis is maintained by resident stem cells and their progeny. However, the underlying mechanisms that control tissue homeostasis are not fully understood. Here, we demonstrate that Debra-mediated Ci degradation is important for intestinal stem cell (ISC) proliferation in Drosophila adult midgut. Debra inhibition leads to increased ISC activity and tissue homeostasis loss, phenocopying defects observed in aging flies. These defects can be suppressed by depleting Ci, ...

  9. Drosophila neuroblasts retain the daughter centrosome

    OpenAIRE

    Januschke, Jens; Llamazares, Salud; Reina, Jose; Gonzalez, Cayetano

    2011-01-01

    During asymmetric mitosis, both in male Drosophila germline stem cells and in mouse embryo neural progenitors, the mother centrosome is retained by the self-renewed cell; hence suggesting that mother centrosome inheritance might contribute to stemness. We test this hypothesis in Drosophila neuroblasts (NBs) tracing photo converted centrioles and a daughter-centriole-specific marker generated by cloning the Drosophila homologue of human Centrobin. Here we show that upon asymmetric mitosis, the...

  10. Signal Propagation in Drosophila Central Neurons

    OpenAIRE

    Gouwens, Nathan W.; Wilson, Rachel I.

    2009-01-01

    Drosophila is an important model organism for investigating neural development, neural morphology, neurophysiology, and neural correlates of behaviors. However, almost nothing is known about how electrical signals propagate in Drosophila neurons. Here we address these issues in antennal lobe projection neurons (PNs), one of the most well-studied classes of Drosophila neurons. We use morphological and electrophysiological data to deduce the passive membrane properties of these neurons and to b...

  11. Pleiotropic actions of the male pheromone cis-vaccenyl acetate in Drosophila melanogaster

    OpenAIRE

    Ejima, Aki

    2015-01-01

    The male-specific lipid, cis-vaccenyl acetate (cVA) has multiple functions in intra-species communication in Drosophila melanogaster. The presence of cVA in a male suppresses courtship motivation of other males and averts male–male courtship. Meanwhile, aggression behaviors between males are promoted by a high amount of cVA caused by increased densities of male flies. cVA also works as a modifier of courtship memory, which is suppressed courtship motivation driven by previous unsuccessful cou...

  12. Integrative Model of Drosophila Flight

    OpenAIRE

    Dickson, William B.; Andrew D Straw; Dickinson, Michael H

    2008-01-01

    This paper presents a framework for simulating the flight dynamics and control strategies of the fruit fly Drosophila melanogaster. The framework consists of five main components: an articulated rigid-body simulation, a model of the aerodynamic forces and moments, a sensory systems model, a control model, and an environment model. In the rigid-body simulation the fly is represented by a system of three rigid bodies connected by a pair of actuated ball joints. At each instant of th...

  13. Chromatin assembly using Drosophila systems.

    Science.gov (United States)

    Fyodorov, Dmitry V; Levenstein, Mark E

    2002-05-01

    To successfully study chromatin structure and activity in vitro, it is essential to have a chromatin assembly system that will prepare extended nucleosome arrays with highly defined protein content that resemble bulk chromatin isolated from living cell nuclei in terms of periodicity and nucleosome positioning. The Drosophila ATP-dependent chromatin assembly system described in this unit meets these requirements. The end product of the reaction described here has highly periodic extended arrays with physiologic spacing and positioning of the nucleosomes.

  14. Visual attention in Drosophila melanogaster

    OpenAIRE

    Sareen, Preeti

    2012-01-01

    There is such vast amount of visual information in our surroundings at any time that filtering out the important information for further processing is a basic requirement for any visual system. This is accomplished by deploying attention to focus on one source of sensory inputs to the exclusion of others (Luck and Mangun 2009). Attention has been studied extensively in humans and non human primates (NHPs). In Drosophila, visual attention was first demonstrated in 1980 (Wolf and Heisenberg 198...

  15. The role of carcinine in signaling at the Drosophila photoreceptor synapse.

    Directory of Open Access Journals (Sweden)

    Brendan A Gavin

    2007-12-01

    Full Text Available The Drosophila melanogaster photoreceptor cell has long served as a model system for researchers focusing on how animal sensory neurons receive information from their surroundings and translate this information into chemical and electrical messages. Electroretinograph (ERG analysis of Drosophila mutants has helped to elucidate some of the genes involved in the visual transduction pathway downstream of the photoreceptor cell, and it is now clear that photoreceptor cell signaling is dependent upon the proper release and recycling of the neurotransmitter histamine. While the neurotransmitter transporters responsible for clearing histamine, and its metabolite carcinine, from the synaptic cleft have remained unknown, a strong candidate for a transporter of either substrate is the uncharacterized inebriated protein. The inebriated gene (ine encodes a putative neurotransmitter transporter that has been localized to photoreceptor cells in Drosophila and mutations in ine result in an abnormal ERG phenotype in Drosophila. Loss-of-function mutations in ebony, a gene required for the synthesis of carcinine in Drosophila, suppress components of the mutant ine ERG phenotype, while loss-of-function mutations in tan, a gene necessary for the hydrolysis of carcinine in Drosophila, have no effect on the ERG phenotype in ine mutants. We also show that by feeding wild-type flies carcinine, we can duplicate components of mutant ine ERGs. Finally, we demonstrate that treatment with H(3 receptor agonists or inverse agonists rescue several components of the mutant ine ERG phenotype. Here, we provide pharmacological and genetic epistatic evidence that ine encodes a carcinine neurotransmitter transporter. We also speculate that the oscillations observed in mutant ine ERG traces are the result of the aberrant activity of a putative H(3 receptor.

  16. Insulin receptor in Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Insulin receptor in Drosophila melanogaster

    International Nuclear Information System (INIS)

    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 125I-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 125I-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 125I-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

  18. 'Peer pressure' in larval Drosophila?

    Science.gov (United States)

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

    2014-01-01

    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

  19. Using Drosophila for Studies of Intermediate Filaments.

    Science.gov (United States)

    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.

  20. Radioresistance and radiosensitivity in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Studying the mechanisms controlling radioresistant in Drosophila the sensibility of four strains of Drosophila melanogaster to sex-linked recessive lethal mutations induced by 5kR Cobalt-60 gamma radiation and 0,006 M EMS or 0,25% of caffeine was determined. (M.A.C.)

  1. Drosophila Fascin is a novel downstream target of prostaglandin signaling during actin remodeling.

    Science.gov (United States)

    Groen, Christopher M; Spracklen, Andrew J; Fagan, Tiffany N; Tootle, Tina L

    2012-12-01

    Although prostaglandins (PGs)-lipid signals produced downstream of cyclooxygenase (COX) enzymes-regulate actin cytoskeletal dynamics, their mechanisms of action are unknown. We previously established Drosophila oogenesis, in particular nurse cell dumping, as a new model to determine how PGs regulate actin remodeling. PGs, and thus the Drosophila COX-like enzyme Pxt, are required for both the parallel actin filament bundle formation and the cortical actin strengthening required for dumping. Here we provide the first link between Fascin (Drosophila Singed, Sn), an actin-bundling protein, and PGs. Loss of either pxt or fascin results in similar actin defects. Fascin interacts, both pharmacologically and genetically, with PGs, as reduced Fascin levels enhance the effects of COX inhibition and synergize with reduced Pxt levels to cause both parallel bundle and cortical actin defects. Conversely, overexpression of Fascin in the germline suppresses the effects of COX inhibition and genetic loss of Pxt. These data lead to the conclusion that PGs regulate Fascin to control actin remodeling. This novel interaction has implications beyond Drosophila, as both PGs and Fascin-1, in mammalian systems, contribute to cancer cell migration and invasion.

  2. Variation in the susceptibility of Drosophila to different entomopathogenic nematodes.

    Science.gov (United States)

    Peña, Jennifer M; Carrillo, Mayra A; Hallem, Elissa A

    2015-03-01

    Entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema are lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species of Drosophila fruit flies as model hosts. We show that the EPN Steinernema carpocapsae, which is widely used for insect control, is capable of infecting and killing D. melanogaster larvae. S. carpocapsae is associated with the bacterium Xenorhabdus nematophila, and we show that X. nematophila induces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence toward D. melanogaster and that Drosophila species vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection.

  3. Altered lipid metabolism in a Drosophila model of Friedreich's ataxia.

    Science.gov (United States)

    Navarro, Juan A; Ohmann, Elisabeth; Sanchez, Diego; Botella, José A; Liebisch, Gerhard; Moltó, María D; Ganfornina, María D; Schmitz, Gerd; Schneuwly, Stephan

    2010-07-15

    Friedreich's ataxia (FRDA) is the most common form of autosomal recessive ataxia caused by a deficit in the mitochondrial protein frataxin. Although demyelination is a common symptom in FRDA patients, no multicellular model has yet been developed to study the involvement of glial cells in FRDA. Using the recently established RNAi lines for targeted suppression of frataxin in Drosophila, we were able to study the effects of general versus glial-specific frataxin downregulation. In particular, we wanted to study the interplay between lowered frataxin content, lipid accumulation and peroxidation and the consequences of these effects on the sensitivity to oxidative stress and fly fitness. Interestingly, ubiquitous frataxin reduction leads to an increase in fatty acids catalyzing an enhancement of lipid peroxidation levels, elevating the intracellular toxic potential. Specific loss of frataxin in glial cells triggers a similar phenotype which can be visualized by accumulating lipid droplets in glial cells. This phenotype is associated with a reduced lifespan, an increased sensitivity to oxidative insult, neurodegenerative effects and a serious impairment of locomotor activity. These symptoms fit very well with our observation of an increase in intracellular toxicity by lipid peroxides. Interestingly, co-expression of a Drosophila apolipoprotein D ortholog (glial lazarillo) has a strong protective effect in our frataxin models, mainly by controlling the level of lipid peroxidation. Our results clearly support a strong involvement of glial cells and lipid peroxidation in the generation of FRDA-like symptoms.

  4. Prostaglandins temporally regulate cytoplasmic actin bundle formation during Drosophila oogenesis.

    Science.gov (United States)

    Spracklen, Andrew J; Kelpsch, Daniel J; Chen, Xiang; Spracklen, Cassandra N; Tootle, Tina L

    2014-02-01

    Prostaglandins (PGs)--lipid signals produced downstream of cyclooxygenase (COX) enzymes--regulate actin dynamics in cell culture and platelets, but their roles during development are largely unknown. Here we define a new role for Pxt, the Drosophila COX-like enzyme, in regulating the actin cytoskeleton--temporal restriction of actin remodeling during oogenesis. PGs are required for actin filament bundle formation during stage 10B (S10B). In addition, loss of Pxt results in extensive early actin remodeling, including actin filaments and aggregates, within the posterior nurse cells of S9 follicles; wild-type follicles exhibit similar structures at a low frequency. Hu li tai shao (Hts-RC) and Villin (Quail), an actin bundler, localize to all early actin structures, whereas Enabled (Ena), an actin elongation factor, preferentially localizes to those in pxt mutants. Reduced Ena levels strongly suppress early actin remodeling in pxt mutants. Furthermore, loss of Pxt results in reduced Ena localization to the sites of bundle formation during S10B. Together these data lead to a model in which PGs temporally regulate actin remodeling during Drosophila oogenesis by controlling Ena localization/activity, such that in S9, PG signaling inhibits, whereas at S10B, it promotes Ena-dependent actin remodeling.

  5. Growth hormone suppression test

    Science.gov (United States)

    GH suppression test; Glucose loading test; Acromegaly - blood test; Gigantism - blood test ... during the suppression test, the provider will suspect gigantism or acromegaly. You may need to be retested to confirm ...

  6. Dexamethasone suppression test

    Science.gov (United States)

    DST; ACTH suppression test; Cortisol suppression test ... During this test, you will receive dexamethasone. This is a strong man-made (synthetic) glucocorticoid medication. Afterward, your blood is drawn ...

  7. The Interplay between Myc and CTP Synthase in Drosophila.

    Science.gov (United States)

    Aughey, Gabriel N; Grice, Stuart J; Liu, Ji-Long

    2016-02-01

    CTP synthase (CTPsyn) is essential for the biosynthesis of pyrimidine nucleotides. It has been shown that CTPsyn is incorporated into a novel cytoplasmic structure which has been termed the cytoophidium. Here, we report that Myc regulates cytoophidium formation during Drosophila oogenesis. We have found that Myc protein levels correlate with cytoophidium abundance in follicle epithelia. Reducing Myc levels results in cytoophidium loss and small nuclear size in follicle cells, while overexpression of Myc increases the length of cytoophidia and the nuclear size of follicle cells. Ectopic expression of Myc induces cytoophidium formation in late stage follicle cells. Furthermore, knock-down of CTPsyn is sufficient to suppress the overgrowth phenotype induced by Myc overexpression, suggesting CTPsyn acts downstream of Myc and is required for Myc-mediated cell size control. Taken together, our data suggest a functional link between Myc, a renowned oncogene, and the essential nucleotide biosynthetic enzyme CTPsyn. PMID:26889675

  8. Taste processing in Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi A. Apostolopoulou

    2015-10-01

    Full Text Available The sense of taste allows animals to detect chemical substances in their environment to initiate appropriate behaviors: to find food or a mate, to avoid hostile environments and predators. Drosophila larvae are a promising model organism to study gustation. Their simple nervous system triggers stereotypic behavioral responses, and the coding of taste can be studied by genetic tools at the single cell level. This review briefly summarizes recent progress on how taste information is sensed and processed by larval cephalic and pharyngeal sense organs. The focus lies on several studies, which revealed cellular and molecular mechanisms required to process sugar, salt, and bitter substances.

  9. Syntaxin 5 is required for copper homeostasis in Drosophila and mammals.

    Directory of Open Access Journals (Sweden)

    Melanie Norgate

    Full Text Available Copper is essential for aerobic life, but many aspects of its cellular uptake and distribution remain to be fully elucidated. A genome-wide screen for copper homeostasis genes in Drosophila melanogaster identified the SNARE gene Syntaxin 5 (Syx5 as playing an important role in copper regulation; flies heterozygous for a null mutation in Syx5 display increased tolerance to high dietary copper. The phenotype is shown here to be due to a decrease in copper accumulation, a mechanism also observed in both Drosophila and human cell lines. Studies in adult Drosophila tissue suggest that very low levels of Syx5 result in neuronal defects and lethality, and increased levels also generate neuronal defects. In contrast, mild suppression generates a phenotype typical of copper-deficiency in viable, fertile flies and is exacerbated by co-suppression of the copper uptake gene Ctr1A. Reduced copper uptake appears to be due to reduced levels at the plasma membrane of the copper uptake transporter, Ctr1. Thus Syx5 plays an essential role in copper homeostasis and is a candidate gene for copper-related disease in humans.

  10. Pre- and Postsynaptic Role of Dopamine D2 Receptor DD2R in Drosophila Olfactory Associative Learning.

    Science.gov (United States)

    Qi, Cheng; Lee, Daewoo

    2014-01-01

    Dopaminergic neurons in Drosophila play critical roles in diverse brain functions such as motor control, arousal, learning, and memory. Using genetic and behavioral approaches, it has been firmly established that proper dopamine signaling is required for olfactory classical conditioning (e.g., aversive and appetitive learning). Dopamine mediates its functions through interaction with its receptors. There are two different types of dopamine receptors in Drosophila: D1-like (dDA1, DAMB) and D2-like receptors (DD2R). Currently, no study has attempted to characterize the role of DD2R in Drosophila learning and memory. Using a DD2R-RNAi transgenic line, we have examined the role of DD2R, expressed in dopamine neurons (i.e., the presynaptic DD2R autoreceptor), in larval olfactory learning. The function of postsynaptic DD2R expressed in mushroom body (MB) was also studied as MB is the center for Drosophila learning, with a function analogous to that of the mammalian hippocampus. Our results showed that suppression of presynaptic DD2R autoreceptors impairs both appetitive and aversive learning. Similarly, postsynaptic DD2R in MB neurons appears to be involved in both appetitive and aversive learning. The data confirm, for the first time, that DD2R plays an important role in Drosophila olfactory learning. PMID:25422852

  11. Complete mitochondrial genome of Drosophila albomicans.

    Science.gov (United States)

    Kang, Xiongbin; Luo, Xiao; Zhang, Zhi; Zhang, Zhen; Yang, Junqing; Bi, Guiqi

    2016-09-01

    Drosophila albomicans has been widely used as an important animal model for chromosome evolution. In this study, the mitochondrial genome sequence of this species is determined and described for the first time. The mitochondrial genome (15 849 bp) encompasses two rRNA, 22 tRNA, and 13 protein-coding genes. Genome content and structure are similar to those reported from other Drosophila mitochondrial genomes. Phylogeny analysis indicates that D. albomicans have a closer genetic relationship with Drosophil aincompta and Drosophil alittoralis. This mitochondrial genome is potentially important for studying molecular evolution and conservation genetics in Drosophila genus. PMID:26358579

  12. Cellular immunity and pathogen strategies in combative interactions involving Drosophila hosts and their endoparasitic wasps

    Directory of Open Access Journals (Sweden)

    AJ Nappi

    2010-09-01

    Full Text Available Various cellular innate immune responses protect invertebrates from attack by eukaryotic pathogens. In insects, assessments of the factor(s causing, or contributing to, pathogen mortality have long considered as toxic components certain molecules associated with enzyme-mediated melanogenesis. In Drosophila hosts, observations that have prompted additional or alternative considerations are those that document either the survival of certain endoparasitic wasps despite melanotic encapsulation, or the destruction of the parasite with no evidence of this type of host response. Investigations of the production of some reactive intermediates of oxygen and nitrogen during infection provide a basis for proposing that these molecules constitute important elements of the immune arsenal of Drosophila. Studies of the target specificity of virulence factors injected by female wasps during infection that suppress the host immune response will likely facilitate identification of the toxic host molecules, and contribute to a more detailed understanding of the cell-signaling pathways that regulate their synthesis.

  13. JAK/STAT signaling in Drosophila muscles controls the cellular immune response against parasitoid infection.

    Science.gov (United States)

    Yang, Hairu; Kronhamn, Jesper; Ekström, Jens-Ola; Korkut, Gül Gizem; Hultmark, Dan

    2015-12-01

    The role of JAK/STAT signaling in the cellular immune response of Drosophila is not well understood. Here, we show that parasitoid wasp infection activates JAK/STAT signaling in somatic muscles of the Drosophila larva, triggered by secretion of the cytokines Upd2 and Upd3 from circulating hemocytes. Deletion of upd2 or upd3, but not the related os (upd1) gene, reduced the cellular immune response, and suppression of the JAK/STAT pathway in muscle cells reduced the encapsulation of wasp eggs and the number of circulating lamellocyte effector cells. These results suggest that JAK/STAT signaling in muscles participates in a systemic immune defense against wasp infection.

  14. Tachykinin-expressing neurons control male-specific aggressive arousal in Drosophila.

    Science.gov (United States)

    Asahina, Kenta; Watanabe, Kiichi; Duistermars, Brian J; Hoopfer, Eric; González, Carlos Roberto; Eyjólfsdóttir, Eyrún Arna; Perona, Pietro; Anderson, David J

    2014-01-16

    Males of most species are more aggressive than females, but the neural mechanisms underlying this dimorphism are not clear. Here, we identify a neuron and a gene that control the higher level of aggression characteristic of Drosophila melanogaster males. Males, but not females, contain a small cluster of FruM(+) neurons that express the neuropeptide tachykinin (Tk). Activation and silencing of these neurons increased and decreased, respectively, intermale aggression without affecting male-female courtship behavior. Mutations in both Tk and a candidate receptor, Takr86C, suppressed the effect of neuronal activation, whereas overexpression of Tk potentiated it. Tk neuron activation overcame reduced aggressiveness caused by eliminating a variety of sensory or contextual cues, suggesting that it promotes aggressive arousal or motivation. Tachykinin/Substance P has been implicated in aggression in mammals, including humans. Thus, the higher aggressiveness of Drosophila males reflects the sexually dimorphic expression of a neuropeptide that controls agonistic behaviors across phylogeny. PMID:24439378

  15. A Drosophila metallophosphoesterase mediates deglycosylation of rhodopsin

    OpenAIRE

    Cao, Jinguo; Li, Yi; Xia, Wenjing; Reddig, Keith; Hu, Wen; XIE, Wei; Li, Hong-Sheng; Han, Junhai

    2011-01-01

    The glycosylation status of Rhodopsin controls its trafficking and stability, and is hence critical for photoreceptor function. Here, a Drosophila metallophosphoesterase is identified that affects Rhodopsin glycosylation by regulating the activity of an enzyme involved in glycan processing.

  16. Modeling tumor invasion and metastasis in Drosophila

    Directory of Open Access Journals (Sweden)

    Wayne O. Miles

    2011-11-01

    Full Text Available Conservation of major signaling pathways between humans and flies has made Drosophila a useful model organism for cancer research. Our understanding of the mechanisms regulating cell growth, differentiation and development has been considerably advanced by studies in Drosophila. Several recent high profile studies have examined the processes constraining the metastatic growth of tumor cells in fruit fly models. Cell invasion can be studied in the context of an in vivo setting in flies, enabling the genetic requirements of the microenvironment of tumor cells undergoing metastasis to be analyzed. This Perspective discusses the strengths and limitations of Drosophila models of cancer invasion and the unique tools that have enabled these studies. It also highlights several recent reports that together make a strong case for Drosophila as a system with the potential for both testing novel concepts in tumor progression and cell invasion, and for uncovering players in metastasis.

  17. Lipid metabolism in Drosophila: development and disease

    Institute of Scientific and Technical Information of China (English)

    Zhonghua Liu; Xun Huang

    2013-01-01

    Proteins,nucleic acids,and lipids are three major components of the cell.Despite a few basic metabolic pathways,we know very little about lipids,compared with the explosion of knowledge about proteins and nucleic acids.How many different forms of lipids are there? What are the in vivo functions of individual lipid? How does lipid metabolism contribute to normal development and human health? Many of these questions remain unanswered.For over a century,the fruit fly Drosophila melanogaster has been used as a model organism to study basic biological questions.In recent years,increasing evidences proved that Drosophila models are highly valuable for lipid metabolism and energy homeostasis researches.Some recent progresses of lipid metabolic regulation during Drosophila development and in Drosophila models of human diseases will be discussed in this review.

  18. Behavioral modification in choice process of Drosophila

    Institute of Scientific and Technical Information of China (English)

    WANG; Shunpeng; (王顺鹏); TANG; Shiming; (唐世明); LI; Yan; (李; 岩); GUO; Aike; (郭爱克)

    2003-01-01

    In visual operant conditioning of Drosophila at the flight simulator, only motor output of flies--yaw torque--is recorded, which is involved in the conditioning process. The current study used a newly-designed data analysis method to study the torque distribution of Drosophila. Modification of torque distribution represents the effects of operant conditioning on flies' behavioral mode. Earlier works[10] showed that, when facing contradictory visual cues, flies could make choices based upon the relative weightiness of different cues, and it was demonstrated that mushroom bodies might play an important role in such choice behavior. The new "torque-position map" method was used to explore the CS-US associative learning and choice behavior in Drosophila from the aspect of its behavioral mode. Finally, this work also discussed various possible neural bases involved in visual associative learning, choice processing and modification processing of the behavioral mode in the visual operant conditioning of Drosophila.

  19. Genetic Determinants of Phosphate Response in Drosophila

    OpenAIRE

    Clemens Bergwitz; Wee, Mark J.; Sumi Sinha; Joanne Huang; Charles DeRobertis; Mensah, Lawrence B.; Jonathan Cohen; Adam Friedman; Meghana Kulkarni; Yanhui Hu; Arunachalam Vinayagam; Michael Schnall-Levin; Bonnie Berger; Perkins, Lizabeth A.; Mohr, Stephanie E.

    2012-01-01

    Phosphate is required for many important cellular processes and having too little phosphate or too much can cause disease and reduce life span in humans. However, the mechanisms underlying homeostatic control of extracellular phosphate levels and cellular effects of phosphate are poorly understood. Here, we establish Drosophila melanogaster as a model system for the study of phosphate effects. We found that Drosophila larval development depends on the availability of phosphate in the medium. ...

  20. The Drosophila cyst stem cell lineage

    OpenAIRE

    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 ...

  1. RNA Binding Specificity of Drosophila Muscleblind†

    OpenAIRE

    Goers, Emily S.; Voelker, Rodger B.; Gates, Devika P.; Berglund, J. Andrew

    2008-01-01

    Members of the muscleblind family of RNA binding proteins found in Drosophila and mammals are key players in both the human disease myotonic dystrophy and the regulation of alternative splicing. Recently, the mammalian muscleblind-like protein, MBNL1, has been shown to have interesting RNA binding properties with both endogenous and disease-related RNA targets. Here we report the characterization of RNA binding properties of the Drosophila muscleblind protein Mbl. Mutagenesis of double-strand...

  2. The Digestive Tract of Drosophila melanogaster

    OpenAIRE

    Bassler, Bl; Lichten, M; Schupbach, G.; Lemaitre, Bruno; Miguel-Aliaga, Irene

    2013-01-01

    The digestive tract plays a central role in the digestion and absorption of nutrients. Far from being a passive tube, it provides the first line of defense against pathogens and maintains energy homeostasis by exchanging neuronal and endocrine signals with other organs. Historically neglected, the gut of the fruit fly Drosophila melanogaster has recently come to the forefront of Drosophila research. Areas as diverse as stem cell biology, neurobiology, metabolism, and immunity are benefitting ...

  3. DNA TOPOISOMERASE I INHIBITORS AMELIORATE SEIZURE-LIKE BEHAVIORS AND PARALYSIS IN A DROSOPHILA MODEL OF EPILEPSY

    OpenAIRE

    Song, Juan; Parker, Louise; Hormozi, Linda; Tanouye, Mark A

    2008-01-01

    The Drosophila DNA topoisomerase type I mutant allele, top1JS is an effective general seizure-suppressor mutation, reverting seizure-sensitive phenotypes of several mutant strains in a genetic model of epilepsy. Seizure-suppression is caused by reduced transcription of the top1 gene (Song et al., 2007). Here, we examine the possibility that pharmaceutical inhibition of Top1 enzymatic activity may also be effective at reducing seizure phenotypes. We investigate the effect of vertebrate Top1 in...

  4. A Drosophila Model for Screening Antiobesity Agents

    Science.gov (United States)

    Men, Tran Thanh; Thanh, Duong Ngoc Van; Yamaguchi, Masamitsu; Suzuki, Takayoshi; Hattori, Gen; Arii, Masayuki; Huy, Nguyen Tien; Kamei, Kaeko

    2016-01-01

    Although triacylglycerol, the major component for lipid storage, is essential for normal physiology, its excessive accumulation causes obesity in adipose tissue and is associated with organ dysfunction in nonadipose tissue. Here, we focused on the Drosophila model to develop therapeutics for preventing obesity. The brummer (bmm) gene in Drosophila melanogaster is known to be homologous with human adipocyte triglyceride lipase, which is related to the regulation of lipid storage. We established a Drosophila model for monitoring bmm expression by introducing the green fluorescent protein (GFP) gene as a downstream reporter of the bmm promoter. The third-instar larvae of Drosophila showed the GFP signal in all tissues observed and specifically in the salivary gland nucleus. To confirm the relationship between bmm expression and obesity, the effect of oral administration of glucose diets on bmm promoter activity was analyzed. The Drosophila flies given high-glucose diets showed higher lipid contents, indicating the obesity phenotype; this was suggested by a weaker intensity of the GFP signal as well as reduced bmm mRNA expression. These results demonstrated that the transgenic Drosophila model established in this study is useful for screening antiobesity agents. We also report the effects of oral administration of histone deacetylase inhibitors and some vegetables on the bmm promoter activity. PMID:27247940

  5. A Drosophila Model for Screening Antiobesity Agents

    Directory of Open Access Journals (Sweden)

    Tran Thanh Men

    2016-01-01

    Full Text Available Although triacylglycerol, the major component for lipid storage, is essential for normal physiology, its excessive accumulation causes obesity in adipose tissue and is associated with organ dysfunction in nonadipose tissue. Here, we focused on the Drosophila model to develop therapeutics for preventing obesity. The brummer (bmm gene in Drosophila melanogaster is known to be homologous with human adipocyte triglyceride lipase, which is related to the regulation of lipid storage. We established a Drosophila model for monitoring bmm expression by introducing the green fluorescent protein (GFP gene as a downstream reporter of the bmm promoter. The third-instar larvae of Drosophila showed the GFP signal in all tissues observed and specifically in the salivary gland nucleus. To confirm the relationship between bmm expression and obesity, the effect of oral administration of glucose diets on bmm promoter activity was analyzed. The Drosophila flies given high-glucose diets showed higher lipid contents, indicating the obesity phenotype; this was suggested by a weaker intensity of the GFP signal as well as reduced bmm mRNA expression. These results demonstrated that the transgenic Drosophila model established in this study is useful for screening antiobesity agents. We also report the effects of oral administration of histone deacetylase inhibitors and some vegetables on the bmm promoter activity.

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

    Science.gov (United States)

    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...

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

    OpenAIRE

    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).

  8. Development of dendrite polarity in Drosophila neurons

    Directory of Open Access Journals (Sweden)

    Hill Sarah E

    2012-10-01

    Full Text Available Abstract Background Drosophila neurons have dendrites that contain minus-end-out microtubules. This microtubule arrangement is different from that of cultured mammalian neurons, which have mixed polarity microtubules in dendrites. Results To determine whether Drosophila and mammalian dendrites have a common microtubule organization during development, we analyzed microtubule polarity in Drosophila dendritic arborization neuron dendrites at different stages of outgrowth from the cell body in vivo. As dendrites initially extended, they contained mixed polarity microtubules, like mammalian neurons developing in culture. Over a period of several days this mixed microtubule array gradually matured to a minus-end-out array. To determine whether features characteristic of dendrites were localized before uniform polarity was attained, we analyzed dendritic markers as dendrites developed. In all cases the markers took on their characteristic distribution while dendrites had mixed polarity. An axonal marker was also quite well excluded from dendrites throughout development, although this was perhaps more efficient in mature neurons. To confirm that dendrite character could be acquired in Drosophila while microtubules were mixed, we genetically disrupted uniform dendritic microtubule organization. Dendritic markers also localized correctly in this case. Conclusions We conclude that developing Drosophila dendrites initially have mixed microtubule polarity. Over time they mature to uniform microtubule polarity. Dendrite identity is established before the mature microtubule arrangement is attained, during the period of mixed microtubule polarity.

  9. Ancient Male Recombination Shaped Genetic Diversity of Neo-Y Chromosome in Drosophila albomicans.

    Science.gov (United States)

    Satomura, Kazuhiro; Tamura, Koichiro

    2016-02-01

    Researchers studying Y chromosome evolution have drawn attention to neo-Y chromosomes in Drosophila species due to their resembling the initial stage of Y chromosome evolution. In the studies of neo-Y chromosome of Drosophila miranda, the extremely low genetic diversity observed suggested various modes of natural selection acting on the nonrecombining genome. However, alternative possibility may come from its peculiar origin from a single chromosomal fusion event with male achiasmy, which potentially caused and maintained the low genetic diversity of the neo-Y chromosome. Here, we report a real case where a neo-Y chromosome is in transition from an autosome to a typical Y chromosome. The neo-Y chromosome of Drosophila albomicans harbored a rich genetic diversity comparable to its gametologous neo-X chromosome and an autosome in the same genome. Analyzing sequence variations in 53 genes and measuring recombination rates between pairs of loci by cross experiments, we elucidated the evolutionary scenario of the neo-Y chromosome of D. albomicans having high genetic diversity without assuming selective force, i.e., it originated from a single chromosomal fusion event, experienced meiotic recombination during the initial stage of evolution and diverged from neo-X chromosome by the suppression of recombination tens or a few hundreds of thousand years ago. Consequently, the observed high genetic diversity on the neo-Y chromosome suggested a strong effect of meiotic recombination to introduce genetic variations into the newly arisen sex chromosome. PMID:26494844

  10. Neurl4 contributes to germ cell formation and integrity in Drosophila

    Directory of Open Access Journals (Sweden)

    Jennifer Jones

    2015-08-01

    Full Text Available Primordial germ cells (PGCs form at the posterior pole of the Drosophila embryo, and then migrate to their final destination in the gonad where they will produce eggs or sperm. Studies of the different stages in this process, including assembly of germ plasm in the oocyte during oogenesis, specification of a subset of syncytial embryonic nuclei as PGCs, and migration, have been informed by genetic analyses. Mutants have defined steps in the process, and the identities of the affected genes have suggested biochemical mechanisms. Here we describe a novel PGC phenotype. When Neurl4 activity is reduced, newly formed PGCs frequently adopt irregular shapes and appear to bud off vesicles. PGC number is also reduced, an effect exacerbated by a separate role for Neurl4 in germ plasm formation during oogenesis. Like its mammalian homolog, Drosophila Neurl4 protein is concentrated in centrosomes and downregulates centrosomal protein CP110. Reducing CP110 activity suppresses the abnormal PGC morphology of Neurl4 mutants. These results extend prior analyses of Neurl4 in cultured cells, revealing a heightened requirement for Neurl4 in germ-line cells in Drosophila.

  11. Co-evolving CENP-A and CAL1 Domains Mediate Centromeric CENP-A Deposition across Drosophila Species.

    Science.gov (United States)

    Rosin, Leah; Mellone, Barbara G

    2016-04-18

    Centromeres mediate the conserved process of chromosome segregation, yet centromeric DNA and the centromeric histone, CENP-A, are rapidly evolving. The rapid evolution of Drosophila CENP-A loop 1 (L1) is thought to modulate the DNA-binding preferences of CENP-A to counteract centromere drive, the preferential transmission of chromosomes with expanded centromeric satellites. Consistent with this model, CENP-A from Drosophila bipectinata (bip) cannot localize to Drosophila melanogaster (mel) centromeres. We show that this result is due to the inability of the mel CENP-A chaperone, CAL1, to deposit bip CENP-A into chromatin. Co-expression of bip CENP-A and bip CAL1 in mel cells restores centromeric localization, and similar findings apply to other Drosophila species. We identify two co-evolving regions, CENP-A L1 and the CAL1 N terminus, as critical for lineage-specific CENP-A incorporation. Collectively, our data show that the rapid evolution of L1 modulates CAL1-mediated CENP-A assembly, suggesting an alternative mechanism for the suppression of centromere drive. PMID:27093083

  12. Apoptosis in Drosophila: which role for mitochondria?

    Science.gov (United States)

    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. PMID:26679112

  13. Live cell imaging in Drosophila melanogaster.

    Science.gov (United States)

    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. PMID:20360379

  14. Debra-Mediated Ci Degradation Controls Tissue Homeostasis in Drosophila Adult Midgut

    Directory of Open Access Journals (Sweden)

    Zhouhua Li

    2014-02-01

    Full Text Available Adult tissue homeostasis is maintained by resident stem cells and their progeny. However, the underlying mechanisms that control tissue homeostasis are not fully understood. Here, we demonstrate that Debra-mediated Ci degradation is important for intestinal stem cell (ISC proliferation in Drosophila adult midgut. Debra inhibition leads to increased ISC activity and tissue homeostasis loss, phenocopying defects observed in aging flies. These defects can be suppressed by depleting Ci, suggesting that increased Hedgehog (Hh signaling contributes to ISC proliferation and tissue homeostasis loss. Consistently, Hh signaling activation causes the same defects, whereas depletion of Hh signaling suppresses these defects. Furthermore, the Hh ligand from multiple sources is involved in ISC proliferation and tissue homeostasis. Finally, we show that the JNK pathway acts downstream of Hh signaling to regulate ISC proliferation. Together, our results provide insights into the mechanisms of stem cell proliferation and tissue homeostasis control.

  15. Multiple-pathway analysis of double-strand break repair mutations in Drosophila.

    Directory of Open Access Journals (Sweden)

    Dena M Johnson-Schlitz

    2007-04-01

    Full Text Available The analysis of double-strand break (DSB repair is complicated by the existence of several pathways utilizing a large number of genes. Moreover, many of these genes have been shown to have multiple roles in DSB repair. To address this complexity we used a repair reporter construct designed to measure multiple repair outcomes simultaneously. This approach provides estimates of the relative usage of several DSB repair pathways in the premeiotic male germline of Drosophila. We applied this system to mutations at each of 11 repair loci plus various double mutants and altered dosage genotypes. Most of the mutants were found to suppress one of the pathways with a compensating increase in one or more of the others. Perhaps surprisingly, none of the single mutants suppressed more than one pathway, but they varied widely in how the suppression was compensated. We found several cases in which two or more loci were similar in which pathway was suppressed while differing in how this suppression was compensated. Taken as a whole, the data suggest that the choice of which repair pathway is used for a given DSB occurs by a two-stage "decision circuit" in which the DSB is first placed into one of two pools from which a specific pathway is then selected.

  16. Automated measurement of Drosophila wings

    Directory of Open Access Journals (Sweden)

    Mezey Jason

    2003-12-01

    Full Text Available Abstract Background Many studies in evolutionary biology and genetics are limited by the rate at which phenotypic information can be acquired. The wings of Drosophila species are a favorable target for automated analysis because of the many interesting questions in evolution and development that can be addressed with them, and because of their simple structure. Results We have developed an automated image analysis system (WINGMACHINE that measures the positions of all the veins and the edges of the wing blade of Drosophilid flies. A video image is obtained with the aid of a simple suction device that immobilizes the wing of a live fly. Low-level processing is used to find the major intersections of the veins. High-level processing then optimizes the fit of an a priori B-spline model of wing shape. WINGMACHINE allows the measurement of 1 wing per minute, including handling, imaging, analysis, and data editing. The repeatabilities of 12 vein intersections averaged 86% in a sample of flies of the same species and sex. Comparison of 2400 wings of 25 Drosophilid species shows that wing shape is quite conservative within the group, but that almost all taxa are diagnosably different from one another. Wing shape retains some phylogenetic structure, although some species have shapes very different from closely related species. The WINGMACHINE system facilitates artificial selection experiments on complex aspects of wing shape. We selected on an index which is a function of 14 separate measurements of each wing. After 14 generations, we achieved a 15 S.D. difference between up and down-selected treatments. Conclusion WINGMACHINE enables rapid, highly repeatable measurements of wings in the family Drosophilidae. Our approach to image analysis may be applicable to a variety of biological objects that can be represented as a framework of connected lines.

  17. Characterization of novel microsatellites from Drosophila transversa.

    Science.gov (United States)

    Räisänen, L; Roininen, E; Liimatainen, J O

    2009-03-01

    We investigated a partial genomic library of Drosophila transversa for microsatellites and developed 12 markers for genetic analyses. This is the first time that microsatellite primers from the quinaria species group have been described. Four loci were cross-amplified in D. phalerata. Nine out of the 12 microsatellite markers developed are likely to be on the X chromosome. PMID:21564716

  18. Drosophila lifespan enhancement by exogenous bacteria

    OpenAIRE

    Brummel, Ted; Ching, Alisa; Seroude, Laurent; Simon, Anne F.; Benzer, Seymour

    2004-01-01

    We researched the lifespan of Drosophila under axenic conditions compared with customary procedure. The experiments revealed that the presence of bacteria during the first week of adult life can enhance lifespan, despite unchanged food intake. Later in life, the presence of bacteria can reduce lifespan. Certain long-lived mutants react in different ways, indicating an interplay between bacteria and longevity-enhancing genes.

  19. Polarity and intracellular compartmentalization of Drosophila neurons

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    Henner Astra L

    2007-04-01

    Full Text Available Abstract Background Proper neuronal function depends on forming three primary subcellular compartments: axons, dendrites, and soma. Each compartment has a specialized function (the axon to send information, dendrites to receive information, and the soma is where most cellular components are produced. In mammalian neurons, each primary compartment has distinctive molecular and morphological features, as well as smaller domains, such as the axon initial segment, that have more specialized functions. How neuronal subcellular compartments are established and maintained is not well understood. Genetic studies in Drosophila have provided insight into other areas of neurobiology, but it is not known whether flies are a good system in which to study neuronal polarity as a comprehensive analysis of Drosophila neuronal subcellular organization has not been performed. Results Here we use new and previously characterized markers to examine Drosophila neuronal compartments. We find that: axons and dendrites can accumulate different microtubule-binding proteins; protein synthesis machinery is concentrated in the cell body; pre- and post-synaptic sites localize to distinct regions of the neuron; and specializations similar to the initial segment are present. In addition, we track EB1-GFP dynamics and determine microtubules in axons and dendrites have opposite polarity. Conclusion We conclude that Drosophila will be a powerful system to study the establishment and maintenance of neuronal compartments.

  20. Radiation effects on the drosophila melanogaster genoma

    International Nuclear Information System (INIS)

    When DNA of living beings has been damaged, the cells show different responses depending on their physiological state. Repair mechanisms can be classified into two groups: constitutive which are always present in the cells and inductible, which must be stimulated to show themselves. It is suggested that a repair mechanism exists in the drosophila ovules which act upon the damage present in mature spermatozoids. Our aim is to verify whether or not a radiation dosis applied to the female drosophila will modify the frequency of individuals which have lost the paternal sex chromosomes. YW/YW virgin females and XEZ males and fbb-/bS Y y+ y were mated for two days in order to collect radiation treated spermatozoids. The results were consistent as to the parameters being evaluated and lead one to suppose that the radiation applied to the female drosophila produced some changes in the ovule metabolism which reduced the frequency of individuals with lost chromosomes. It is believed that ionizing radiation interferes with the repair mechanisms that are existent and constitutive, retarding and hindering the restoration of chromosome fragments and this brings about death of the zygote or death of the eggs which lessens the frequencies of individuals carriers of chromosomic aberrations. Ionizing radiations applied to the female drosophila modifies the frequency of loss of patternal chromosomes and comes about when the radiation dose to the female is 700 rad. (Author)

  1. Biological effects of radon in Drosophila

    International Nuclear Information System (INIS)

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  2. Organization of descending neurons in Drosophila melanogaster.

    Science.gov (United States)

    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

  3. Optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    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.

  4. Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres

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    Grazia Daniela Raffa

    2013-05-01

    Full Text Available Drosophila lacks telomerase and fly telomeres are elongated by occasional transposition of three specialized retroelements. Drosophila telomeres do not terminate with GC-rich repeats and are assembled independently of the sequence of chromosome ends. Recent work has shown that Drosophila telomeres are capped by the terminin complex, which includes the fast-evolving proteins HOAP, HipHop, Moi and Ver. These proteins are not conserves outside Drosophilidae and localize and function exclusively at telomeres, protecting them from fusion events. Other proteins required to prevent end-to-end fusion in flies include HP1, Eff/UbcD1, ATM, the components of the Mre11-Rad50-Nbs (MRN complex, and the Woc transcription factor. These proteins do not share the terminin properties; they are evolutionarily conserved non-fast-evolving proteins that do not accumulate only telomeres and do not serve telomere-specific functions. We propose that following telomerase loss, Drosophila rapidly evolved terminin to bind chromosome ends in a sequence-independent manner. This hypothesis suggests that terminin is the functional analog of the shelterin complex that protects human telomeres. The non-terminin proteins are instead likely to correspond to ancestral telomere-associated proteins that did not evolve as rapidly as terminin because of the functional constraints imposed by their involvement in diverse cellular processes. Thus, it appears that the main difference between Drosophila and human telomeres is in the protective complexes that specifically associate with the DNA termini. We believe that Drosophila telomeres offer excellent opportunities for investigations on human telomere biology. The identification of additional Drosophila genes encoding non-terminin proteins involved in telomere protection might lead to the discovery of novel components of human telomeres.

  5. Hidden Complications of Thought Suppression

    OpenAIRE

    Najmi, Sadia; Wegner, Daniel M.

    2009-01-01

    Although the suppression of thoughts may seem to be an effective solution, this strategy can lead to an exacerbation of the very thought that one is attempting to suppress. This ironic effect is the most obvious unwanted outcome of suppression and has now been investigated empirically for more than two decades. However, the fact that suppression is an effortful process implies that, even when suppression does not lead to an ironic rebound of the unwanted thought, it puts an insidious cognitiv...

  6. USP5 Is Dispensable for Monoubiquitin Maintenance in Drosophila.

    Science.gov (United States)

    Ristic, Gorica; Tsou, Wei-Ling; Guzi, Ermal; Kanack, Adam J; Scaglione, Kenneth Matthew; Todi, Sokol V

    2016-04-22

    Ubiquitination is a post-translational modification that regulates most cellular pathways and processes, including degradation of proteins by the proteasome. Substrate ubiquitination is controlled at various stages, including through its reversal by deubiquitinases (DUBs). A critical outcome of this process is the recycling of monoubiquitin. One DUB whose function has been proposed to include monoubiquitin recycling is USP5. Here, we investigated whether Drosophila USP5 is important for maintaining monoubiquitin in vivo We found that the fruit fly orthologue of USP5 has catalytic preferences similar to its human counterpart and that this DUB is necessary during fly development. Our biochemical and genetic experiments indicate that reduction of USP5 does not lead to monoubiquitin depletion in developing flies. Also, introduction of exogenous ubiquitin does not suppress developmental lethality caused by loss of endogenous USP5. Our work indicates that a primary physiological role of USP5 is not to recycle monoubiquitin for reutilization, but that it may involve disassembly of conjugated ubiquitin to maintain proteasome function. PMID:26917723

  7. Behavioral Analysis of Bitter Taste Perception in Drosophila Larvae.

    Science.gov (United States)

    Kim, Haein; Choi, Min Sung; Kang, KyeongJin; Kwon, Jae Young

    2016-01-01

    Insect larvae, which recognize food sources through chemosensory cues, are a major source of global agricultural loss. Gustation is an important factor that determines feeding behavior, and the gustatory receptors (Grs) act as molecular receptors that recognize diverse chemicals in gustatory receptor neurons (GRNs). The behavior of Drosophila larvae is relatively simpler than the adult fly, and a gustatory receptor-to-neuron map was established in a previous study of the major external larval head sensory organs. Here, we extensively study the bitter taste responses of larvae using 2-choice behavioral assays. First, we tested a panel of 23 candidate bitter compounds to compare the behavioral responses of larvae and adults. We define 9 bitter compounds which elicit aversive behavior in a dose-dependent manner. A functional map of the larval GRNs was constructed with the use of Gr-GAL4 lines that drive expression of UAS-tetanus toxin and UAS-VR1 in specific gustatory neurons to identify bitter tastants-GRN combinations by suppressing and activating discrete subsets of taste neurons, respectively. Our results suggest that many gustatory neurons act cooperatively in larval bitter sensing, and that these neurons have different degrees of responsiveness to different bitter compounds.

  8. Mutants dissecting development and behaviour in drosophila

    International Nuclear Information System (INIS)

    We have traced in this paper the progress in Drosophila genetics research from the 1960s, at the IARI, spearheaded by the visionary insight of M. S. Swaminathan. The work started with the study of indirect effect of radiation and the synergistic interaction of physical and chemical mutagens on chromosomal and genetic changes. This paved the way for the study of single gene mutants in dissecting developmental and behavioural processes. New genes discovered by us have been shown to encode conserved cell signalling molecules controlling developmental and behavioural pathways. With the complete sequencing of the Drosophila genome, in the year 2000, mounting evidence for the homology between Drosophila and human genes controlling genetic disorders became available. This has led to the fly becoming an indispensable tool for studying human diseases as well as a model to test for drugs and pharmaceuticals against human diseases and complex behavioural processes. For example wingless in Drosophila belongs to the conserved Wnt gene family and aberrant WNT signalling is linked to a range of human diseases, most notably cancer. Inhibition as well as activation of WNT signalling form the basis of an effective therapy for some cancers as well as several other clinical conditions. Recent experiments have shown that WNTs might also normally participate in self-renewal, proliferation or differentiation of stem cells and altering WNT signalling might be beneficial to the use of stem cells for therapeutic means. Likewise, the stambhA mutant of Drosophila which was discovered for its temperature-dependent paralytic behaviour is the fly homologue of Phospholipase Cβ. Phospholipase C mediated G protein signalling plays a central role in vital processes controlling epilepsy, vision, taste, and olfaction in animals. Proteins of the G-signalling pathway are of intense research interest since many human diseases involve defects in G-protein signalling pathways. In fact, approximately 50

  9. Plasticity in the Drosophila larval visual System

    Directory of Open Access Journals (Sweden)

    Abud J Farca-Luna

    2013-07-01

    Full Text Available The remarkable ability of the nervous system to modify its structure and function is mostly experience and activity modulated. The molecular basis of neuronal plasticity has been studied in higher behavioral processes, such as learning and memory formation. However, neuronal plasticity is not restricted to higher brain functions, but may provide a basic feature of adaptation of all neural circuits. The fruit fly Drosophila melanogaster provides a powerful genetic model to gain insight into the molecular basis of nervous system development and function. The nervous system of the larvae is again a magnitude simpler than its adult counter part, allowing the genetic assessment of a number of individual genetically identifiable neurons. We review here recent progress on the genetic basis of neuronal plasticity in developing and functioning neural circuits focusing on the simple visual system of the Drosophila larva.

  10. Remembering components of food in Drosophila

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    Gaurav eDas

    2016-02-01

    Full Text Available 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 that innervate distinct functional zones on the mushroom bodies. 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. Dopaminergic neurons 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.

  11. [The comeback of mitochondria in Drosophila apoptosis].

    Science.gov (United States)

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

    2016-05-01

    The role of the mitochondrion in mammalian cell apoptosis has been established since the mid-1990s. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, notably because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and apoptosis in Drosophila cell death occurs at the mitochondrial level. Numerous proteins that appear key for Drosophila apoptosis regulation constitutively or transiently bind to mitochondria. They participate in the cell death process at different levels such as degradation of an IAP caspase inhibitor, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. The aim of this review is to take stock of these events that might have their counterpart in humans. PMID:27225920

  12. Motor Control of Drosophila Courtship Song

    Directory of Open Access Journals (Sweden)

    Troy R. Shirangi

    2013-11-01

    Full Text Available Many animals utilize acoustic signals—or songs—to attract mates. During courtship, Drosophila melanogaster males vibrate a wing to produce trains of pulses and extended tone, called pulse and sine song, respectively. Courtship songs in the genus Drosophila are exceedingly diverse, and different song features appear to have evolved independently of each other. How the nervous system allows such diversity to evolve is not understood. Here, we identify a wing muscle in D. melanogaster (hg1 that is uniquely male-enlarged. The hg1 motoneuron and the sexually dimorphic development of the hg1 muscle are required specifically for the sine component of the male song. In contrast, the motoneuron innervating a sexually monomorphic wing muscle, ps1, is required specifically for a feature of pulse song. Thus, individual wing motor pathways can control separate aspects of courtship song and may provide a “modular” anatomical substrate for the evolution of diverse songs.

  13. Exquisite Light Sensitivity of Drosophila melanogaster Cryptochrome

    Science.gov (United States)

    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. PMID:23874218

  14. Exquisite light sensitivity of Drosophila melanogaster cryptochrome.

    Directory of Open Access Journals (Sweden)

    Pooja Vinayak

    Full Text Available 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.

  15. Imaging Calcium in Drosophila at Egg Activation.

    Science.gov (United States)

    Derrick, Christopher J; York-Andersen, Anna H; Weil, Timothy T

    2016-01-01

    Egg activation is a universal process that includes a series of events to allow the fertilized egg to complete meiosis and initiate embryonic development. One aspect of egg activation, conserved across all organisms examined, is a change in the intracellular concentration of calcium (Ca(2+)) often termed a 'Ca(2+) wave'. While the speed and number of oscillations of the Ca(2+) wave varies between species, the change in intracellular Ca(2+) is key in bringing about essential events for embryonic development. These changes include resumption of the cell cycle, mRNA regulation, cortical granule exocytosis, and rearrangement of the cytoskeleton. In the mature Drosophila egg, activation occurs in the female oviduct prior to fertilization, initiating a series of Ca(2+)-dependent events. Here we present a protocol for imaging the Ca(2+) wave in Drosophila. This approach provides a manipulable model system to interrogate the mechanism of the Ca(2+) wave and the downstream changes associated with it. PMID:27584955

  16. Interactions between surround suppression and interocular suppression in human vision.

    Directory of Open Access Journals (Sweden)

    Yong-Chun Cai

    Full Text Available Several types of suppression phenomena have been observed in the visual system. For example, the ability to detect a target stimulus is often impaired when the target is embedded in a high-contrast surround. This contextual modulation, known as surround suppression, was formerly thought to occur only in the periphery. Another type of suppression phenomena is interocular suppression, in which the sensitivity to a monocular target is reduced by a superimposed mask in the opposite eye. Here, we explored how the two types of suppression operating across different spatial regions interact with one another when they simultaneously exert suppressive influences on a common target presented at the fovea. In our experiments, a circular target grating presented to the fovea of one eye was suppressed interocularly by a noise pattern of the same size in the other eye. The foveal stimuli were either shown alone or surrounded by a monocular annular grating. The orientation and eye-of-origin of the surround grating were varied. We found that the detection of the foveal target subjected to interocular suppression was severely impaired by the addition of the surround grating, indicating strong surround suppression in the fovea. In contrast, when the interocular suppression was released by superimposing a binocular fusion ring onto both the target and the dichoptic mask, the surround suppression effect was found to be dramatically decreased. In addition, the surround suppression was found to depend on the contrast of the dichoptic noise with the greatest surround suppression effect being obtained only when the noise contrast was at an intermediate level. These findings indicate that surround suppression and interocular suppression are not independent of each other, but there are strong interactions between them. Moreover, our results suggest that strong surround suppression may also occur at the fovea and not just the periphery.

  17. Recombineering Homologous Recombination Constructs in Drosophila

    OpenAIRE

    Carreira-Rosario, Arnaldo; Scoggin, Shane; Shalaby, Nevine A.; Williams, Nathan David; Hiesinger, P. Robin; Buszczak, Michael

    2013-01-01

    The continued development of techniques for fast, large-scale manipulation of endogenous gene loci will broaden the use of Drosophila melanogaster as a genetic model organism for human-disease related research. Recent years have seen technical advancements like homologous recombination and recombineering. However, generating unequivocal null mutations or tagging endogenous proteins remains a substantial effort for most genes. Here, we describe and demonstrate techniques for using recombineeri...

  18. Three-dimensional imaging of Drosophila melanogaster.

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    Leeanne McGurk

    Full Text Available BACKGROUND: The major hindrance to imaging the intact adult Drosophila is that the dark exoskeleton makes it impossible to image through the cuticle. We have overcome this obstacle and describe a method whereby the internal organs of adult Drosophila can be imaged in 3D by bleaching and clearing the adult and then imaging using a technique called optical projection tomography (OPT. The data is displayed as 2D optical sections and also in 3D to provide detail on the shape and structure of the adult anatomy. METHODOLOGY: We have used OPT to visualize in 2D and 3D the detailed internal anatomy of the intact adult Drosophila. In addition this clearing method used for OPT was tested for imaging with confocal microscopy. Using OPT we have visualized the size and shape of neurodegenerative vacuoles from within the head capsule of flies that suffer from age-related neurodegeneration due to a lack of ADAR mediated RNA-editing. In addition we have visualized tau-lacZ expression in 2D and 3D. This shows that the wholemount adult can be stained without any manipulation and that this stain penetrates well as we have mapped the localization pattern with respect to the internal anatomy. CONCLUSION: We show for the first time that the intact adult Drosophila can be imaged in 3D using OPT, also we show that this method of clearing is also suitable for confocal microscopy to image the brain from within the intact head. The major advantage of this is that organs can be represented in 3D in their natural surroundings. Furthermore optical sections are generated in each of the three planes and are not prone to the technical limitations that are associated with manual sectioning. OPT can be used to dissect mutant phenotypes and to globally map gene expression in both 2D and 3D.

  19. Structure and Development of Glia in Drosophila

    OpenAIRE

    Hartenstein, Volker

    2011-01-01

    Insect glia represents a conspicuous and diverse population of cells and plays a role in controlling neuronal progenitor proliferation, axonal growth, neuronal differentiation and maintenance, and neuronal function. Genetic studies in Drosophila have elucidated many aspects of glial structure, function and development. Just as in vertebrates, it appears as if different classes of glial cells are specialized for different functions. Based on topology and cell shape, glial cells of the central ...

  20. The development of the Drosophila larval brain.

    Science.gov (United States)

    Hartenstein, Volker; Spindler, Shana; Pereanu, Wayne; Fung, Siaumin

    2008-01-01

    In this chapter we will start out by describing in more detail the progenitors of the nervous system, the neuroblasts and ganglion mother cells. Subsequently we will survey the generic cell types that make up the developing Drosophila brain, namely neurons, glial cells and tracheal cells. Finally, we will attempt a synopsis of the neuronal connectivity of the larval brain that can be deduced from the analysis of neural lineages and their relationship to neuropile compartments. PMID:18683635

  1. A Drosophila melanogaster model of classic galactosemia

    OpenAIRE

    Kushner, Rebekah F.; Ryan, Emily L.; Sefton, Jennifer M. I.; Rebecca D Sanders; Lucioni, Patricia Jumbo; Kenneth H Moberg; Fridovich-Keil, Judith L.

    2010-01-01

    Classic galactosemia is a potentially lethal disorder that results from profound impairment of galactose-1-phosphate uridylyltransferase (GALT). Despite decades of research, the underlying pathophysiology of classic galactosemia remains unclear, in part owing to the lack of an appropriate animal model. Here, we report the establishment of a Drosophila melanogaster model of classic galactosemia; this is the first whole-animal genetic model to mimic aspects of the patient phenotype. Analogous t...

  2. Quantification of Food Intake in Drosophila

    OpenAIRE

    Richard Wong; Matthew D W Piper; Bregje Wertheim; Linda Partridge

    2009-01-01

    Measurement of food intake in the fruit fly Drosophila melanogaster is often necessary for studies of behaviour, nutrition and drug administration. There is no reliable and agreed method for measuring food intake of flies in undisturbed, steady state, and normal culture conditions. We report such a method, based on measurement of feeding frequency by proboscis-extension, validated by short-term measurements of food dye intake. We used the method to demonstrate that (a) female flies feed more ...

  3. Tools for neuroanatomy and neurogenetics in Drosophila

    OpenAIRE

    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

    2008-01-01

    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 gene...

  4. Functional neuroanatomy of Drosophila olfactory memory formation

    OpenAIRE

    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 and aversive reinforcers: (1) Which neurons within the olfactory nervous system mediate the acquisition of memory? (2) What is the complete neural circuitry exten...

  5. Detection of Cell Death in Drosophila Tissues

    Science.gov (United States)

    Vasudevan, Deepika; Ryoo, Hyung Don

    2016-01-01

    Drosophila has served as a particularly attractive model to study cell death due to the vast array of tools for genetic manipulation under defined spatial and temporal conditions in vivo as well as in cultured cells. These genetic methods have been well supplemented by enzymatic assays and a panel of antibodies recognizing cell death markers. This chapter discusses reporters, mutants and assays used by various laboratories to study cell death in the context of development and in response to external insults. PMID:27108437

  6. Visualizing the spindle checkpoint in Drosophila spermatocytes

    OpenAIRE

    Rebollo, Elena; González, Cayetano

    2000-01-01

    The spindle assembly checkpoint detects defects in spindle structure or in the alignment of the chromosomes on the metaphase plate and delays the onset of anaphase until defects are corrected. Thus far, the evidence regarding the presence of a spindle checkpoint during meiosis in male Drosophila has been indirect and contradictory. On the one hand, chromosomes without pairing partners do not prevent meiosis progression. On the other hand, some conserved components of the spindle checkpoint ma...

  7. A Taste of the Drosophila Gustatory Receptors

    OpenAIRE

    Montell, Craig

    2009-01-01

    Insects such as the fruit fly, Drosophila melanogaster, rely on contact chemosensation to detect nutrient-rich foods, to avoid consuming toxic chemicals, and to select mates and hospitable zones to deposit eggs. Flies sense tastants and non-volatile pheromones through gustatory bristles and pegs distributed on multiple body parts including the proboscis, wing margins, legs and ovipositor. The sensilla house gustatory receptor neurons, which express members of the family of 68 gustatory recept...

  8. Visualizing the spindle checkpoint in Drosophila spermatocytes

    Science.gov (United States)

    Rebollo, Elena; González, Cayetano

    2000-01-01

    The spindle assembly checkpoint detects defects in spindle structure or in the alignment of the chromosomes on the metaphase plate and delays the onset of anaphase until defects are corrected. Thus far, the evidence regarding the presence of a spindle checkpoint during meiosis in male Drosophila has been indirect and contradictory. On the one hand, chromosomes without pairing partners do not prevent meiosis progression. On the other hand, some conserved components of the spindle checkpoint machinery are expressed in these cells and behave as their homologue proteins do in systems with an active spindle checkpoint. To establish whether the spindle checkpoint is active in Drosophila spermatocytes we have followed meiosis progression by time-lapse microscopy under conditions where the checkpoint is likely to be activated. We have found that the presence of a relatively high number of misaligned chromosomes or a severe disruption of the meiotic spindle results in a significant delay in the time of entry into anaphase. These observations provide the first direct evidence substantiating the activity of a meiotic spindle checkpoint in male Drosophila. PMID:11256627

  9. Global patterns of sequence evolution in Drosophila

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    Marín Ignacio

    2007-11-01

    Full Text Available Abstract Background Sequencing of the genomes of several Drosophila allows for the first precise analyses of how global sequence patterns change among multiple, closely related animal species. A basic question is whether there are characteristic features that differentiate chromosomes within a species or between different species. Results We explored the euchromatin of the chromosomes of seven Drosophila species to establish their global patterns of DNA sequence diversity. Between species, differences in the types and amounts of simple sequence repeats were found. Within each species, the autosomes have almost identical oligonucleotide profiles. However, X chromosomes and autosomes have, in all species, a qualitatively different composition. The X chromosomes are less complex than the autosomes, containing both a higher amount of simple DNA sequences and, in several cases, chromosome-specific repetitive sequences. Moreover, we show that the right arm of the X chromosome of Drosophila pseudoobscura, which evolved from an autosome 10 – 18 millions of years ago, has a composition which is identical to that of the original, left arm of the X chromosome. Conclusion The consistent differences among species, differences among X chromosomes and autosomes and the convergent evolution of X and neo-X chromosomes demonstrate that strong forces are acting on drosophilid genomes to generate peculiar chromosomal landscapes. We discuss the relationships of the patterns observed with differential recombination and mutation rates and with the process of dosage compensation.

  10. ‘Peer pressure’ in larval Drosophila?

    Directory of Open Access Journals (Sweden)

    Thomas Niewalda

    2014-06-01

    Full Text Available 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.

  11. Pervasive natural selection in the Drosophila genome?

    Directory of Open Access Journals (Sweden)

    Guy Sella

    2009-06-01

    Full Text Available Over the past four decades, the predominant view of molecular evolution saw little connection between natural selection and genome evolution, assuming that the functionally constrained fraction of the genome is relatively small and that adaptation is sufficiently infrequent to play little role in shaping patterns of variation within and even between species. Recent evidence from Drosophila, reviewed here, suggests that this view may be invalid. Analyses of genetic variation within and between species reveal that much of the Drosophila genome is under purifying selection, and thus of functional importance, and that a large fraction of coding and noncoding differences between species are adaptive. The findings further indicate that, in Drosophila, adaptations may be both common and strong enough that the fate of neutral mutations depends on their chance linkage to adaptive mutations as much as on the vagaries of genetic drift. The emerging evidence has implications for a wide variety of fields, from conservation genetics to bioinformatics, and presents challenges to modelers and experimentalists alike.

  12. dachshund Potentiates Hedgehog Signaling during Drosophila Retinogenesis

    Science.gov (United States)

    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

  13. Abl suppresses cell extrusion and intercalation during epithelium folding.

    Science.gov (United States)

    Jodoin, Jeanne N; Martin, Adam C

    2016-09-15

    Tissue morphogenesis requires control over cell shape changes and rearrangements. In the Drosophila mesoderm, linked epithelial cells apically constrict, without cell extrusion or intercalation, to fold the epithelium into a tube that will then undergo epithelial-to-mesenchymal transition (EMT). Apical constriction drives tissue folding or cell extrusion in different contexts, but the mechanisms that dictate the specific outcomes are poorly understood. Using live imaging, we found that Abelson (Abl) tyrosine kinase depletion causes apically constricting cells to undergo aberrant basal cell extrusion and cell intercalation. abl depletion disrupted apical-basal polarity and adherens junction organization in mesoderm cells, suggesting that extruding cells undergo premature EMT. The polarity loss was associated with abnormal basolateral contractile actomyosin and Enabled (Ena) accumulation. Depletion of the Abl effector Enabled (Ena) in abl-depleted embryos suppressed the abl phenotype, consistent with cell extrusion resulting from misregulated ena Our work provides new insight into how Abl loss and Ena misregulation promote cell extrusion and EMT.

  14. Tremor suppression in ECG

    Directory of Open Access Journals (Sweden)

    Mihov Georgy S

    2008-11-01

    Full Text Available Abstract Background Electrocardiogram recordings are very often contaminated by high-frequency noise usually power-line interference and EMG disturbances (tremor. Specific method for interference cancellation without affecting the proper ECG components, called subtraction procedure, was developed some two decades ago. Filtering out the tremor remains a priori partially successful since it has a relatively wide spectrum, which overlaps the useful ECG frequency band. Method The proposed method for tremor suppression implements the following three procedures. Contaminated ECG signals are subjected to moving averaging (comb filter with linear phase characteristic with first zero set at 50 Hz to suppress tremor and PL interference simultaneously. The reduced peaks of QRS complexes and other relatively high and steep ECG waves are then restored by an introduced by us procedure called linearly-angular, so that the useful high frequency components are preserved in the range specified by the embedded in the ECG instrument filter, usually up to 125 Hz. Finally, a Savitzky-Golay smoothing filter is applied for supplementary tremor suppression outside the QRS complexes. Results The results obtained show a low level of the residual EMG disturbances together with negligible distortion of the wave shapes regardless of rhythm and morphology changes.

  15. Ionizing radiation causes the stress response in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Potentiality of the stress-reaction arising in Drosophila melanogaster under gamma-irradiation of the source with 137Cs (irradiation dose is 10 Gy , radiation dose rate amounts 180 c Gy/min) is studied. It is shown that radiation induces the stress-reaction in Drosophila resulting in alterations in energetic metabolism (biogenic amines metabolic system) and in reproductive function

  16. The developmental transcriptome of Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. The Drosophila Netrin receptor frazzled/DCC functions as an invasive tumor suppressor

    Directory of Open Access Journals (Sweden)

    Duman-Scheel Molly

    2011-06-01

    Full Text Available Abstract Background Loss of heterozygosity at 18q, which includes the Deleted in Colorectal Cancer (DCC gene, has been linked to many human cancers. However, it is unclear if loss of DCC is the specific underlying cause of these cancers. The Drosophila imaginal discs are excellent systems in which to study DCC function, as it is possible to model human tumors through the generation of somatic clones of cells bearing multiple genetic lesions. Here, these attributes of the fly system were utilized to investigate the potential tumor suppressing functions of the Drosophila DCC homologue frazzled (fra during eye-antennal disc development. Results Most fra loss of function clones are eliminated during development. However, when mutant clone cells generated in the developing eye were rescued from death, partially differentiated eye cells were found outside of the normal eye field, and in extreme cases distant sites of the body. Characterization of these cells during development indicates that fra mutant cells display characteristics of invasive tumor cells, including increased levels of phospho-ERK, phospho-JNK, and Mmp-1, changes in cadherin expression, remodeling of the actin cytoskeleton, and loss of polarity. Mutation of fra promotes basement membrane degradation and invasion which are repressed by inhibition of Rho1 signaling. Although inhibition of JNK signaling blocks invasive phenotypes in some metastatic cancer models in flies, blocking JNK signaling inhibits fra mutant cell death, thereby enhancing the fra mutant phenotype. Conclusions The results of this investigation provide the first direct link between point mutations in fra/DCC and metastatic phenotypes in an animal model and suggest that Fra functions as an invasive tumor suppressor during Drosophila development.

  18. Intestinal stem cells in the adult Drosophila midgut

    International Nuclear Information System (INIS)

    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: ► The homeostasis and regeneration of adult fly midguts are mediated by ISCs. ► Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). ► EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. ► Notch signaling regulates ISC self-renewal and differentiation.

  19. Rhodopsin 7–The unusual Rhodopsin in Drosophila

    Science.gov (United States)

    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

  20. Role of JAK/STAT signaling in neuroepithelial stem cell maintenance and proliferation in the Drosophila optic lobe

    International Nuclear Information System (INIS)

    Highlights: → JAK/STAT activity is graded in the Drosophila optic lobe neuroepithelium. → Inactivation of JAK signaling causes disintegration of the optic lobe neuroepithelium and depletion of the neuroepithelial stem cells. → JAK pathway overactivation promotes neuroepithelial overgrowth. → Notch signaling acts downstream of JAK/STAT to promote neuroepithelial growth and expansion. -- Abstract: During Drosophila optic lobe development, proliferation and differentiation must be tightly modulated to reach its normal size for proper functioning. The JAK/STAT pathway plays pleiotropic roles in Drosophila development and in the larval brain, has been shown to inhibit medulla neuroblast formation. In this study, we find that JAK/STAT activity is required for the maintenance and proliferation of the neuroepithelial stem cells in the optic lobe. In loss-of-function JAK/STAT mutant brains, the neuroepithelial cells lose epithelial cell characters and differentiate prematurely while ectopic activation of this pathway is sufficient to induce neuroepithelial overgrowth in the optic lobe. We further show that Notch signaling acts downstream of JAK/STAT to control the maintenance and growth of the optic lobe neuroepithelium. Thus, in addition to its role in suppression of neuroblast formation, the JAK/STAT pathway is necessary and sufficient for optic lobe neuroepithelial growth.

  1. Isolation of protease-free alcohol dehydrogenase (ADH) from Drosophila simulans and several homozygous and heterozygous Drosophila melanogaster variants

    NARCIS (Netherlands)

    Smilda, T; Lamme, DA; Collu, G; Jekel, PA; Reinders, P; Beintema, JJ

    1998-01-01

    The enzyme alcohol dehydrogenase (ADH) from several naturally occurring ADH variants of Drosophila melanogaster and Drosophila simulans Lc,as isolated. Affinity chromatography with the ligand Cibacron Blue and elution with NAD(+) showed similar behavior for D. melanogaster ADH-FF, ADH-71k, and D. si

  2. Molecular cloning, functional expression, and gene silencing of two Drosophila receptors for the Drosophila neuropeptide pyrokinin-2

    DEFF Research Database (Denmark)

    Rosenkilde, Carina; Cazzamali, Giuseppe; Williamson, Michael;

    2003-01-01

    embryos and first instar larvae. In addition to the two Drosophila receptors, we also identified two probable pyrokinin receptors in the genomic database from the malaria mosquito Anopheles gambiae. The two Drosophila pyrokinin receptors are, to our knowledge, the first invertebrate pyrokinin receptors...

  3. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  4. Effects of PP4 suppression on the proliferation of MCF7 cells

    Institute of Scientific and Technical Information of China (English)

    NING Lifeng; LONG Zhitao; HUANG Xiuqing; SUN Lingling; SANG Jianli

    2006-01-01

    PP4, one of the few protein phosphatases associated with centrosome in cells of many species such as Drosophila, C. elegans and mammals, plays an essential role in the regulation of centrosome functions in Drosophila and C. elegans. In order to explore the role of PP4 in mammalian cells, full-length PP4 gene was obtained by RT-PCR from MCF7 cell total RNA and inserted into eukaryotic expression vector pEGFP-C1. The resultant construct pEGFP-C1-PP4 was transfected into MCF7 cells and immunostaining was carried out to confirm the centrosome localization of PP4. Then we reversely subcloned a non-conserved domain of PP4 into pXJ41 to construct an anti-sense vector pXJ41- as-PP4. By transfecting pXJ41-as-PP4 into MCF7 cells and screening with G418, we obtained a stable cell line in which PP4 expression was stably suppressed. The cell line was analyzed on cell morphology, cytoskeleton structure, growth characteristics and the mitosis process. It was found that the proliferation rate decreased and serum-dependence increased in PP4-suppressed cells. Furthermore, flow cytometry and mitotic index analysis showed that G2/M transition was prolonged. PP4 suppression resulted in abnormal interphase microtubule, formation of multipolar spindles and an increase in percentage of multinuclear cells. These results suggested that PP4 is required for centrosome function in mammalian cells.

  5. The pressure suppression system

    International Nuclear Information System (INIS)

    Nuclear plants with boiling water reactors have a safety containment with a pressure suppression system (PSS). Proceeding on significant self-developments, today the three PSS-lines of General Electric Co. (GE), Kraftwerk Union AG (KWU) and ASEA-ATOM are predominant, which are currently represented by the MARK III type, the KWU type 72 and the BWR 75 containment. In addition, there are special developments for the nuclear ship propulsion and for the pressurized water reactors in the Soviet Union. Key design values of the PSS allow a first valuation of its loads during a hypothetical loss-of-coolant accident. (orig.)

  6. Cell survival and proliferation in Drosophila S2 cells following apoptotic stress in the absence of the APAF-1 homolog, ARK, or downstream caspases.

    Science.gov (United States)

    Kiessling, S; Green, D R

    2006-04-01

    In Drosophila, the APAF-1 homolog ARK is required for the activation of the initiator caspase DRONC, which in turn cleaves the effector caspases DRICE and DCP-1. While the function of ARK is important in stress-induced apoptosis in Drosophila S2 cells, as its removal completely suppresses cell death, the decision to undergo apoptosis appears to be regulated at the level of caspase activation, which is controlled by the IAP proteins, particularly DIAP1. Here, we further dissect the apoptotic pathways induced in Drosophila S2 cells in response to stressors and in response to knock-down of DIAP1. We found that the induction of apoptosis was dependent in each case on expression of ARK and DRONC and surviving cells continued to proliferate. We noted a difference in the effects of silencing the executioner caspases DCP-1 and DRICE; knock-down of either or both of these had dramatic effects to sustain cell survival following depletion of DIAP1, but had only minor effects following cellular stress. Our results suggest that the executioner caspases are essential for death following DIAP1 knock-down, indicating that the initiator caspase DRONC may lack executioner functions. The apparent absence of mitochondrial outer membrane permeabilization (MOMP) in Drosophila apoptosis may permit the cell to thrive when caspase activation is disrupted.

  7. Minibrain/Dyrk1a regulates food intake through the Sir2-FOXO-sNPF/NPY pathway in Drosophila and mammals.

    Science.gov (United States)

    Hong, Seung-Hyun; Lee, Kyu-Sun; Kwak, Su-Jin; Kim, Ae-Kyeong; Bai, Hua; Jung, Min-Su; Kwon, O-Yu; Song, Woo-Joo; Tatar, Marc; Yu, Kweon

    2012-01-01

    Feeding behavior is one of the most essential activities in animals, which is tightly regulated by neuroendocrine factors. Drosophila melanogaster short neuropeptide F (sNPF) and the mammalian functional homolog neuropeptide Y (NPY) regulate food intake. Understanding the molecular mechanism of sNPF and NPY signaling is critical to elucidate feeding regulation. Here, we found that minibrain (mnb) and the mammalian ortholog Dyrk1a, target genes of sNPF and NPY signaling, [corrected] regulate food intake in Drosophila melanogaster and mice. In Drosophila melanogaster neuronal cells and mouse hypothalamic cells, sNPF and NPY modulated the mnb and Dyrk1a expression through the PKA-CREB pathway. Increased Dyrk1a activated Sirt1 to regulate the deacetylation of FOXO, which potentiated FOXO-induced sNPF/NPY expression and in turn promoted food intake. Conversely, AKT-mediated insulin signaling suppressed FOXO-mediated sNPF/NPY expression, which resulted in decreasing food intake. Furthermore, human Dyrk1a transgenic mice exhibited decreased FOXO acetylation and increased NPY expression in the hypothalamus, and [corrected] increased food intake. Our findings demonstrate that Mnb/Dyrk1a regulates food intake through the evolutionary conserved Sir2-FOXO-sNPF/NPY pathway in Drosophila melanogaster and mammals.

  8. Minibrain/Dyrk1a regulates food intake through the Sir2-FOXO-sNPF/NPY pathway in Drosophila and mammals.

    Directory of Open Access Journals (Sweden)

    Seung-Hyun Hong

    Full Text Available Feeding behavior is one of the most essential activities in animals, which is tightly regulated by neuroendocrine factors. Drosophila melanogaster short neuropeptide F (sNPF and the mammalian functional homolog neuropeptide Y (NPY regulate food intake. Understanding the molecular mechanism of sNPF and NPY signaling is critical to elucidate feeding regulation. Here, we found that minibrain (mnb and the mammalian ortholog Dyrk1a, target genes of sNPF and NPY signaling, [corrected] regulate food intake in Drosophila melanogaster and mice. In Drosophila melanogaster neuronal cells and mouse hypothalamic cells, sNPF and NPY modulated the mnb and Dyrk1a expression through the PKA-CREB pathway. Increased Dyrk1a activated Sirt1 to regulate the deacetylation of FOXO, which potentiated FOXO-induced sNPF/NPY expression and in turn promoted food intake. Conversely, AKT-mediated insulin signaling suppressed FOXO-mediated sNPF/NPY expression, which resulted in decreasing food intake. Furthermore, human Dyrk1a transgenic mice exhibited decreased FOXO acetylation and increased NPY expression in the hypothalamus, and [corrected] increased food intake. Our findings demonstrate that Mnb/Dyrk1a regulates food intake through the evolutionary conserved Sir2-FOXO-sNPF/NPY pathway in Drosophila melanogaster and mammals.

  9. Extensive Differences in Antifungal Immune Response in Two Drosophila Species Revealed by Comparative Transcriptome Analysis

    Directory of Open Access Journals (Sweden)

    Yosuke Seto

    2013-01-01

    Full Text Available The innate immune system of Drosophila is activated by ingestion of microorganisms. D. melanogaster breeds on fruits fermented by Saccharomyces cerevisiae, whereas D. virilis breeds on slime flux and decaying bark of tree housing a variety of bacteria, yeasts, and molds. In this study, it is shown that D. virilis has a higher resistance to oral infection of a species of filamentous fungi belonging to the genus Penicillium compared to D. melanogaster. In response to the fungal infection, a transcriptome profile of immune-related genes was considerably different between D. melanogaster and D. virilis: the genes encoding antifungal peptides, Drosomycin and Metchnikowin, were highly expressed in D. melanogaster whereas, the genes encoding Diptericin and Defensin were highly expressed in D. virilis. On the other hand, the immune-induced molecule (IM genes showed contrary expression patterns between the two species: they were induced by the fungal infection in D. melanogaster but tended to be suppressed in D. virilis. Our transcriptome analysis also showed newly predicted immune-related genes in D. virilis. These results suggest that the innate immune system has been extensively differentiated during the evolution of these Drosophila species.

  10. The Drosophila effector caspase Dcp-1 regulates mitochondrial dynamics and autophagic flux via SesB.

    Science.gov (United States)

    DeVorkin, Lindsay; Go, Nancy Erro; Hou, Ying-Chen Claire; Moradian, Annie; Morin, Gregg B; Gorski, Sharon M

    2014-05-26

    Increasing evidence reveals that a subset of proteins participates in both the autophagy and apoptosis pathways, and this intersection is important in normal physiological contexts and in pathological settings. In this paper, we show that the Drosophila effector caspase, Drosophila caspase 1 (Dcp-1), localizes within mitochondria and regulates mitochondrial morphology and autophagic flux. Loss of Dcp-1 led to mitochondrial elongation, increased levels of the mitochondrial adenine nucleotide translocase stress-sensitive B (SesB), increased adenosine triphosphate (ATP), and a reduction in autophagic flux. Moreover, we find that SesB suppresses autophagic flux during midoogenesis, identifying a novel negative regulator of autophagy. Reduced SesB activity or depletion of ATP by oligomycin A could rescue the autophagic defect in Dcp-1 loss-of-function flies, demonstrating that Dcp-1 promotes autophagy by negatively regulating SesB and ATP levels. Furthermore, we find that pro-Dcp-1 interacts with SesB in a nonproteolytic manner to regulate its stability. These data reveal a new mitochondrial-associated molecular link between nonapoptotic caspase function and autophagy regulation in vivo. PMID:24862573

  11. Polycomb mediates Myc autorepression and its transcriptional control of many loci in Drosophila

    Science.gov (United States)

    Goodliffe, Julie M.; Wieschaus, Eric; Cole, Michael D.

    2005-01-01

    Aberrant accumulation of the Myc oncoprotein propels proliferation and induces carcinogenesis. In normal cells, however, an abundance of Myc protein represses transcription at the c-myc locus. Cancer cells often lose this autorepression. We examined the control of myc in Drosophila and show here that the Drosophila ortholog, dmyc, also undergoes autorepression. We find that the developmental repressor Polycomb (Pc) is required for dmyc autorepression, and that this Pc-dMyc-mediated repression spreads across an 875-kb region encompassing the dmyc gene. To further investigate the relationship between Myc and Polycomb, we used microarrays to identify genes regulated by each, and identify a striking relationship between the two: A large set of dMyc activation targets is normally repressed by Pc, and 73% of dMyc repression targets require Pc for this repression. Chromatin immunoprecipitation confirmed that many dMyc-Pc-repressed loci have an epigenetic mark recognized by Pc. Our results suggest a novel relationship between Myc and Polycomb, wherein Myc enhances Polycomb repression in order to repress targets, and Myc suppresses Polycomb repression in order to activate targets. PMID:16357214

  12. Specialized piRNA pathways act in germline and somatic tissues of the Drosophila ovary.

    Science.gov (United States)

    Malone, Colin D; Brennecke, Julius; Dus, Monica; Stark, Alexander; McCombie, W Richard; Sachidanandam, Ravi; Hannon, Gregory J

    2009-05-01

    In Drosophila gonads, Piwi proteins and associated piRNAs collaborate with additional factors to form a small RNA-based immune system that silences mobile elements. Here, we analyzed nine Drosophila piRNA pathway mutants for their impacts on both small RNA populations and the subcellular localization patterns of Piwi proteins. We find that distinct piRNA pathways with differing components function in ovarian germ and somatic cells. In the soma, Piwi acts singularly with the conserved flamenco piRNA cluster to enforce silencing of retroviral elements that may propagate by infecting neighboring germ cells. In the germline, silencing programs encoded within piRNA clusters are optimized via a slicer-dependent amplification loop to suppress a broad spectrum of elements. The classes of transposons targeted by germline and somatic piRNA clusters, though not the precise elements, are conserved among Drosophilids, demonstrating that the architecture of piRNA clusters has coevolved with the transposons that they are tasked to control. PMID:19395010

  13. Characterization of a lamellocyte transcriptional enhancer located within the misshapen gene of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Tokusumi

    Full Text Available Drosophila has emerged as an excellent model system in which to study cellular and genetic aspects of hematopoiesis. Under normal developmental conditions and in wild-type genetic backgrounds, Drosophila possesses two types of blood cells, crystal cells and plasmatocytes. Upon infestation by a parasitic wasp or in certain altered genetic backgrounds, a third hemocyte class called the lamellocyte becomes apparent. Herein we describe the characterization of a novel transcriptional regulatory module, a lamellocyte-active enhancer of the misshapen gene. This transcriptional control sequence appears to be inactive in all cell types of the wild-type larva, including crystal cells and plasmatocytes. However, in lamellocytes induced by wasp infestation or by particular genetic conditions, the enhancer is activated and it directs reporter GFP or DsRed expression exclusively in lamellocytes. The lamellocyte control region was delimited to a 140-bp intronic sequence that contains an essential DNA recognition element for the AP-1 transcription factor. Additionally, mutation of the kayak gene encoding the dFos subunit of AP-1 led to a strong suppression of lamellocyte production in tumorous larvae. As misshapen encodes a protein kinase within the Jun N-terminal kinase signaling pathway that functions to form an active AP-1 complex, the lamellocyte-active enhancer likely serves as a transcriptional target within a genetic auto-regulatory circuit that promotes the production of lamellocytes in immune-challenged or genetically-compromised animals.

  14. Extensive differences in antifungal immune response in two Drosophila species revealed by comparative transcriptome analysis.

    Science.gov (United States)

    Seto, Yosuke; Tamura, Koichiro

    2013-01-01

    The innate immune system of Drosophila is activated by ingestion of microorganisms. D. melanogaster breeds on fruits fermented by Saccharomyces cerevisiae, whereas D. virilis breeds on slime flux and decaying bark of tree housing a variety of bacteria, yeasts, and molds. In this study, it is shown that D. virilis has a higher resistance to oral infection of a species of filamentous fungi belonging to the genus Penicillium compared to D. melanogaster. In response to the fungal infection, a transcriptome profile of immune-related genes was considerably different between D. melanogaster and D. virilis: the genes encoding antifungal peptides, Drosomycin and Metchnikowin, were highly expressed in D. melanogaster whereas, the genes encoding Diptericin and Defensin were highly expressed in D. virilis. On the other hand, the immune-induced molecule (IM) genes showed contrary expression patterns between the two species: they were induced by the fungal infection in D. melanogaster but tended to be suppressed in D. virilis. Our transcriptome analysis also showed newly predicted immune-related genes in D. virilis. These results suggest that the innate immune system has been extensively differentiated during the evolution of these Drosophila species. PMID:24151578

  15. The Drosophila effector caspase Dcp-1 regulates mitochondrial dynamics and autophagic flux via SesB.

    Science.gov (United States)

    DeVorkin, Lindsay; Go, Nancy Erro; Hou, Ying-Chen Claire; Moradian, Annie; Morin, Gregg B; Gorski, Sharon M

    2014-05-26

    Increasing evidence reveals that a subset of proteins participates in both the autophagy and apoptosis pathways, and this intersection is important in normal physiological contexts and in pathological settings. In this paper, we show that the Drosophila effector caspase, Drosophila caspase 1 (Dcp-1), localizes within mitochondria and regulates mitochondrial morphology and autophagic flux. Loss of Dcp-1 led to mitochondrial elongation, increased levels of the mitochondrial adenine nucleotide translocase stress-sensitive B (SesB), increased adenosine triphosphate (ATP), and a reduction in autophagic flux. Moreover, we find that SesB suppresses autophagic flux during midoogenesis, identifying a novel negative regulator of autophagy. Reduced SesB activity or depletion of ATP by oligomycin A could rescue the autophagic defect in Dcp-1 loss-of-function flies, demonstrating that Dcp-1 promotes autophagy by negatively regulating SesB and ATP levels. Furthermore, we find that pro-Dcp-1 interacts with SesB in a nonproteolytic manner to regulate its stability. These data reveal a new mitochondrial-associated molecular link between nonapoptotic caspase function and autophagy regulation in vivo.

  16. Stable, precise, and reproducible patterning of bicoid and hunchback molecules in the early Drosophila embryo.

    Directory of Open Access Journals (Sweden)

    Yurie Okabe-Oho

    2009-08-01

    Full Text Available Precise patterning of morphogen molecules and their accurate reading out are of key importance in embryonic development. Recent experiments have visualized distributions of proteins in developing embryos and shown that the gradient of concentration of Bicoid morphogen in Drosophila embryos is established rapidly after fertilization and remains stable through syncytial mitoses. This stable Bicoid gradient is read out in a precise way to distribute Hunchback with small fluctuations in each embryo and in a reproducible way, with small embryo-to-embryo fluctuation. The mechanisms of such stable, precise, and reproducible patterning through noisy cellular processes, however, still remain mysterious. To address these issues, here we develop the one- and three-dimensional stochastic models of the early Drosophila embryo. The simulated results show that the fluctuation in expression of the hunchback gene is dominated by the random arrival of Bicoid at the hunchback enhancer. Slow diffusion of Hunchback protein, however, averages out this intense fluctuation, leading to the precise patterning of distribution of Hunchback without loss of sharpness of the boundary of its distribution. The coordinated rates of diffusion and transport of input Bicoid and output Hunchback play decisive roles in suppressing fluctuations arising from the dynamical structure change in embryos and those arising from the random diffusion of molecules, and give rise to the stable, precise, and reproducible patterning of Bicoid and Hunchback distributions.

  17. CRTC Potentiates Light-independent timeless Transcription to Sustain Circadian Rhythms in Drosophila.

    Science.gov (United States)

    Kim, Minkyung; Lee, Hoyeon; Hur, Jin-Hoe; Choe, Joonho; Lim, Chunghun

    2016-08-31

    Light is one of the strongest environmental time cues for entraining endogenous circadian rhythms. Emerging evidence indicates that CREB-regulated transcription co-activator 1 (CRTC1) is a key player in this pathway, stimulating light-induced Period1 (Per1) transcription in mammalian clocks. Here, we demonstrate a light-independent role of Drosophila CRTC in sustaining circadian behaviors. Genomic deletion of the crtc locus causes long but poor locomotor rhythms in constant darkness. Overexpression or RNA interference-mediated depletion of CRTC in circadian pacemaker neurons similarly impairs the free-running behavioral rhythms, implying that Drosophila clocks are sensitive to the dosage of CRTC. The crtc null mutation delays the overall phase of circadian gene expression yet it remarkably dampens light-independent oscillations of TIMELESS (TIM) proteins in the clock neurons. In fact, CRTC overexpression enhances CLOCK/CYCLE (CLK/CYC)-activated transcription from tim but not per promoter in clock-less S2 cells whereas CRTC depletion suppresses it. Consistently, TIM overexpression partially but significantly rescues the behavioral rhythms in crtc mutants. Taken together, our data suggest that CRTC is a novel co-activator for the CLK/CYC-activated tim transcription to coordinate molecular rhythms with circadian behaviors over a 24-hour time-scale. We thus propose that CRTC-dependent clock mechanisms have co-evolved with selective clock genes among different species.

  18. Discerning the complexity of community interactions using a Drosophila model of polymicrobial infections.

    Directory of Open Access Journals (Sweden)

    Christopher D Sibley

    2008-10-01

    Full Text Available A number of human infections are characterized by the presence of more than one bacterial species and are defined as polymicrobial diseases. Methods for the analysis of the complex biological interactions in mixed infections with a large number of microorganisms are limited and do not effectively determine the contribution of each bacterial species to the pathogenesis of the polymicrobial community. We have developed a novel Drosophila melanogaster infection model to study microbe-microbe interactions and polymicrobe-host interactions. Using this infection model, we examined the interaction of 40 oropharyngeal isolates with Pseudomonas aeruginosa. We observe three classes of microorganisms, one of which acts synergistically with the principal pathogen, while being avirulent or even beneficial on its own. This synergy involves microbe-microbe interactions that result in the modulation of P. aeruginosa virulence factor gene expression within infected Drosophila. The host innate immune response to these natural-route polymicrobial infections is complex and characterized by additive, suppressive, and synergistic transcriptional activation of antimicrobial peptide genes. The polymicrobial infection model was used to differentiate the bacterial flora in cystic fibrosis (CF sputum, revealing that a large proportion of the organisms in CF airways has the ability to influence the outcome of an infection when in combination with the principal CF pathogen P. aeruginosa.

  19. First record of spotted wing drosophila Drosophila suzukii (Diptera: Drosophilidae in Montenegro

    Directory of Open Access Journals (Sweden)

    Snježana Hrnčić

    2015-01-01

    Full Text Available The spotted wing drosophila Drosophila suzukii Matsumura (Diptera: Drosophilidae is an invasive pest originating from Southeast Asia. It was detected for the first time in Europe in 2008 (Spain and Italy and subsequently in other European countries. It is a highly polyphagous pest that infests healthy, ripening fruit and presents a serious threat to fruit production, particularly of soft skinned fruit. In the first half of October 2013, a new fruit fly species was unexpectedly detected in Tephri traps baited with the three-component female-biased attractant BioLure that is regularly used for monitoring the Mediterranean fruit fly Ceratitis capitata Wiedem. (Diptera: Tephritidae in Montenegro. Brief visual inspection identified the new species as the spotted wing drosophila D. suzukii. The pest was first recorded in several localities on the Montenegrin seacoast around Boka Kotor Bay. After the finding, all Drosophila specimens were collected from traps for further laboratory observation. A quick follow-up monitoring of other Tephri traps was carried out within the next few days on the rest of the seacoast (localities from Tivat to Ulcinj. Additionally, Tephri traps were set up around Lake Skadar and in the city of Podgorica, as well as on fresh fruit markets in Podgorica. The results of this preliminary study showed that D. suzukii was present in all surveyed locations and adults were captured until late December. Both sexes were found in traps with BioLure. Our data show that D. suzukii is present in southern parts of Montenegro and there is a serious threat of its further spreading, particularly towards northern parts of the country where the main raspberry and blueberry production is placed. The results also show that Tephri traps baited with BioLure can be used for detection and monitoring of spotted wing drosophila.

  20. Summation of punishment suppression.

    Science.gov (United States)

    Van Houten, R; Rudolph, R

    1971-01-01

    In two experiments, eight rats were trained to lever press with food on a variable-interval schedule. Bar pressing produced shock on a variable-interval schedule in the presence of two independently presented stimuli, a light and a tone. Two rats in each experiment received alternative presentations of the light and the tone and were consequently always in the presence of a stimulus that signalled variable-interval punishment. The other two rats in each experiment were treated similarly except that they received periods in which neither light nor tone was present. During these periods, bar pressing was not punished. The two stimuli that signalled punishment were then presented simultaneously to evaluate the effect of stimulus compounding on response suppression. The subjects trained without punishment-free periods did not show summation to the compound stimulus; the subjects trained with punishment-free periods showed summation of suppression. The major difference between the two experiments was the longer mean interval of variable-interval punishment used in the second experiment. This manipulation made the summation effect more resistant to extinction and thus increased its magnitude. PMID:16811483

  1. Differential roles of HOW in male and female Drosophila germline differentiation.

    Directory of Open Access Journals (Sweden)

    Adrian C Monk

    Full Text Available The adult gonads in both male and female Drosophila melanogaster produce gametes that originate from a regenerative pool of germline stem cells (GSCs. The differentiation programme that produces gametes must be co-ordinated with GSC maintenance and proliferation in order to regulate tissue regeneration. The HOW RNA-binding protein has been shown to maintain mitotic progression of male GSCs and their daughters by maintenance of Cyclin B expression as well as suppressing accumulation of the differentiation factor Bam. Loss of HOW function in the male germline results in loss of GSCs due to a delay in G2 and subsequent apoptosis. Here we show that female how mutant GSCs do not have any cell cycle defects although HOW continues to bind bam mRNA and suppress Bam expression. The role of HOW in suppressing germ cell Bam expression appears to be conserved between sexes, leading to different cellular outcomes in how mutants due to the different functions of Bam. In addition the role in maintaining Cyclin B expression has not been conserved so female how GSCs differentiate rather than arrest.

  2. A study on anti-stress property of Nardostachys jatamamsi on stress induced Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Shilpashree R.

    2011-09-01

    Full Text Available Stress is a feeling that’s created when we react to particular events. It s the body’s way of rising to a challenge and preparing to meet a tough situation with focus, strength, stamina, and heightened alertness. As a result of the stress immune system can be suppressed by chronic stress opening to increased infections and increasing the risk of autoimmune diseases. So one has to learn away to overcome stress. Here is an attempt made to overcome the stress induced in Drosophila melanogaster a model organism, in this study. Methotrexate is used to induce the stress at different concentration taking different group of flies and a Nardostachys jatamamsi plant extract having antistress property is used to relieve the stress induced. This stress relieve measured by the various stress related enzymes like catalase and Superoxide dismutase by this antistress property of the plant Nardostachys jatamamsi was shown.

  3. Functional dissociation in sweet taste receptor neurons between and within taste organs of Drosophila.

    Science.gov (United States)

    Thoma, Vladimiros; Knapek, Stephan; Arai, Shogo; Hartl, Marion; Kohsaka, Hiroshi; Sirigrivatanawong, Pudith; Abe, Ayako; Hashimoto, Koichi; Tanimoto, Hiromu

    2016-01-01

    Finding food sources is essential for survival. Insects detect nutrients with external taste receptor neurons. Drosophila possesses multiple taste organs that are distributed throughout its body. However, the role of different taste organs in feeding remains poorly understood. By blocking subsets of sweet taste receptor neurons, we show that receptor neurons in the legs are required for immediate sugar choice. Furthermore, we identify two anatomically distinct classes of sweet taste receptor neurons in the leg. The axonal projections of one class terminate in the thoracic ganglia, whereas the other projects directly to the brain. These two classes are functionally distinct: the brain-projecting neurons are involved in feeding initiation, whereas the thoracic ganglia-projecting neurons play a role in sugar-dependent suppression of locomotion. Distinct receptor neurons for the same taste quality may coordinate early appetitive responses, taking advantage of the legs as the first appendages to contact food. PMID:26893070

  4. Spatial differences in patterns of modification: selection on hairy in Drosophila melanogaster wings.

    Science.gov (United States)

    Fletcher, R B; Thompson, J N

    2000-01-01

    Artificial selection was carried out for over 45 generations to enhance and suppress expression of the mutation hairy on the Drosophila melanogaster wing. Whole chromosome mapping of X-linked and autosomal modifiers of sense organ number displayed regional differences in magnitude and direction of their effects. Regional specificity of modifier effects was also seen in some interchromosomal interactions. Scanning electron microscopy allowed precise measurement of sense organ size and position along the L3 longitudinal wing vein. Sense organ size varied in a predictable fashion along the proximal-distal axis, and the dorsal pattern differed from the ventral pattern. The high and low selection lines differed most in the proximal portion of the L3 vein. Extra sense organs in the High line were often associated with vein fragments at locations predicted from ancestral vein patterns. Thus, regional specificity of polygenic or quantitative trait locus modifier effects was identified in several different parts of the wing.

  5. Stem-cell-specific endocytic degradation defects lead to intestinal dysplasia in Drosophila

    Directory of Open Access Journals (Sweden)

    Péter Nagy

    2016-05-01

    Full Text Available UV radiation resistance-associated gene (UVRAG is a tumor suppressor involved in autophagy, endocytosis and DNA damage repair, but how its loss contributes to colorectal cancer is poorly understood. Here, we show that UVRAG deficiency in Drosophila intestinal stem cells leads to uncontrolled proliferation and impaired differentiation without preventing autophagy. As a result, affected animals suffer from gut dysfunction and short lifespan. Dysplasia upon loss of UVRAG is characterized by the accumulation of endocytosed ligands and sustained activation of STAT and JNK signaling, and attenuation of these pathways suppresses stem cell hyperproliferation. Importantly, the inhibition of early (dynamin-dependent or late (Rab7-dependent steps of endocytosis in intestinal stem cells also induces hyperproliferation and dysplasia. Our data raise the possibility that endocytic, but not autophagic, defects contribute to UVRAG-deficient colorectal cancer development in humans.

  6. Role of spectraplakin in Drosophila photoreceptor morphogenesis.

    Directory of Open Access Journals (Sweden)

    Uyen Ngoc Mui

    Full Text Available BACKGROUND: Crumbs (Crb, a cell polarity gene, has been shown to provide a positional cue for the apical membrane domain and adherens junction during Drosophila photoreceptor morphogenesis. It has recently been found that stable microtubules in developing Drosophila photoreceptors were linked to Crb localization. Coordinated interactions between microtubule and actin cytoskeletons are involved in many polarized cellular processes. Since Spectraplakin is able to bind both microtubule and actin cytoskeletons, the role of Spectraplakin was analyzed in the regulations of apical Crb domain in developing Drosophila photoreceptors. METHODOLOGY/PRINCIPAL FINDINGS: The localization pattern of Spectraplakin in developing pupal photoreceptors showed a unique intracellular distribution. Spectraplakin localized at rhabdomere terminal web which is at the basal side of the apical Crb or rhabdomere, and in between the adherens junctions. The spectraplakin mutant photoreceptors showed dramatic mislocalizations of Crb, adherens junctions, and the stable microtubules. This role of Spectraplakin in Crb and adherens junction regulation was further supported by spectraplakin's gain-of-function phenotype. Spectraplakin overexpression in photoreceptors caused a cell polarity defect including dramatic mislocalization of Crb, adherens junctions and the stable microtubules in the developing photoreceptors. Furthermore, a strong genetic interaction between spectraplakin and crb was found using a genetic modifier test. CONCLUSIONS/SIGNIFICANCE: In summary, we found a unique localization of Spectraplakin in photoreceptors, and identified the role of spectraplakin in the regulation of the apical Crb domain and adherens junctions through genetic mutational analysis. Our data suggest that Spectraplakin, an actin-microtubule cross-linker, is essential in the apical and adherens junction controls during the photoreceptors morphogenesis.

  7. Acetylation regulates Jun protein turnover in Drosophila.

    Science.gov (United States)

    Zhang, Daoyong; Suganuma, Tamaki; Workman, Jerry L

    2013-11-01

    C-Jun is a major transcription factor belonging to the activating protein 1 (AP-1) family. Phosphorylation has been shown to be critical for c-Jun activation and stability. Here, we report that Jra, the Drosophila Jun protein, is acetylated in vivo. We demonstrate that the acetylation of Jra leads to its rapid degradation in response to osmotic stress. Intriguingly, we also found that Jra phosphorylation antagonized its acetylation, indicating the opposite roles of acetylation and phosphorylation in Jra degradation process under osmotic stress. Our results provide new insights into how c-Jun proteins are precisely regulated by the interplay of different posttranslational modifications.

  8. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    Vasu Sheeba

    2008-12-01

    As an experimental model system, the fruit fly Drosophila melanogaster has been seminal in shaping our understanding of the circadian clockwork. The wealth of genetic tools at our disposal over the past four decades has enabled discovery of the genetic and molecular bases of circadian rhythmicity. More recently, detailed investigation leading to the anatomical, neurochemical and electrophysiological characterization of the various neuronal subgroups that comprise the circadian machinery has revealed pathways through which these neurons come together to act as a neuronal circuit. Thus the D. melanogaster circadian pacemaker circuit presents a relatively simple and attractive model for the study of neuronal circuits and their functions.

  9. Hypergravity-induced altered behavior in Drosophila

    Science.gov (United States)

    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

  10. Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

    DEFF Research Database (Denmark)

    Knecht, Wolfgang; Mikkelsen, N.E.; Clausen, A.R.;

    2009-01-01

    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 angstrom resolution s...... structure of DmdNK 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(....

  11. Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, Wolfgang [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Mikkelsen, Nils Egil [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Clausen, Anders Ranegaard [Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden); Willer, Mette [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Eklund, Hans [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Gojkovic, Zoran [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Piskur, Jure, E-mail: Jure.Piskur@cob.lu.se [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden)

    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.

  12. ‘Peer pressure’ in larval Drosophila?

    OpenAIRE

    Thomas Niewalda; Ines Jeske; Birgit Michels; Bertram Gerber

    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 ...

  13. A connectionist model of the Drosophila blastoderm

    Energy Technology Data Exchange (ETDEWEB)

    Reinitz, J. (Columbia Univ., New York, NY (USA). Dept. of Biological Sciences); Mjolsness, E. (Yale Univ., New Haven, CT (USA). Dept. of Computer Science); Sharp, D.H. (Los Alamos National Lab., NM (USA). 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.

  14. Notch mRNA expression in Drosophila embryos is negatively regulated at the level of mRNA 3' processing.

    Directory of Open Access Journals (Sweden)

    Andrew K Shepherd

    Full Text Available Notch receptor regulates differentiation of almost all tissues and organs during animal development. Many mechanisms function at the protein level to finely regulate Notch activity. Here we provide evidence for Notch regulation at an earlier step - mRNA 3' processing. Processing at the Notch consensus polyadenylation site appears by default to be suppressed in Drosophila embryos. Interference with this suppression, by a mutation, results in increased levels of polyadenylated Notch mRNA, excess Notch signaling, and severe developmental defects. We propose that Notch mRNA 3' processing is negatively regulated to limit the production of Notch protein and render it a controlling factor in the generation of Notch signaling.

  15. Characterization of maltase clusters in the genus Drosophila.

    Science.gov (United States)

    Gabriško, Marek; Janeček, Stefan

    2011-01-01

    To reveal evolutionary history of maltase gene family in the genus Drosophila, we undertook a bioinformatics study of maltase genes from available genomes of 12 Drosophila species. Molecular evolution of a closely related glycoside hydrolase, the α-amylase, in Drosophila has been extensively studied for a long time. The α-amylases were even used as a model of evolution of multigene families. On the other hand, maltase, i.e., the α-glucosidase, got only scarce attention. In this study, we, therefore, investigated spatial organization of the maltase genes in Drosophila genomes, compared the amino acid sequences of the encoded enzymes and analyzed the intron/exon composition of orthologous genes. We found that the Drosophila maltases are more numerous than previously thought (ten instead of three genes) and are localized in two clusters on two chromosomes (2L and 2R). To elucidate the approximate time line of evolution of the clusters, we estimated the order and dated duplication of all the 10 genes. Both clusters are the result of ancient series of subsequent duplication events, which took place from 352 to 61 million years ago, i.e., well before speciation to extant Drosophila species. Also observed was a remarkable intron/exon composition diversity of particular maltase genes of these clusters, probably a result of independent intron loss after duplication of intron-rich gene ancestor, which emerged well before speciation in a common ancestor of all extant Drosophila species.

  16. Contrasting infection strategies in generalist and specialist wasp parasitoids of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Todd A Schlenke

    2007-10-01

    Full Text Available Although host-parasitoid interactions are becoming well characterized at the organismal and cellular levels, much remains to be understood of the molecular bases for the host immune response and the parasitoids' ability to defeat this immune response. Leptopilina boulardi and L. heterotoma, two closely related, highly infectious natural parasitoids of Drosophila melanogaster, appear to use very different infection strategies at the cellular level. Here, we further characterize cellular level differences in the infection characteristics of these two wasp species using newly derived, virulent inbred strains, and then use whole genome microarrays to compare the transcriptional response of Drosophila to each. While flies attacked by the melanogaster group specialist L. boulardi (strain Lb17 up-regulate numerous genes encoding proteolytic enzymes, components of the Toll and JAK/STAT pathways, and the melanization cascade as part of a combined cellular and humoral innate immune response, flies attacked by the generalist L. heterotoma (strain Lh14 do not appear to initiate an immune transcriptional response at the time points post-infection we assayed, perhaps due to the rapid venom-mediated lysis of host hemocytes (blood cells. Thus, the specialist parasitoid appears to invoke a full-blown immune response in the host, but suppresses and/or evades downstream components of this response. Given that activation of the host immune response likely depletes the energetic resources of the host, the specialist's infection strategy seems relatively disadvantageous. However, we uncover the mechanism for one potentially important fitness tradeoff of the generalist's highly immune suppressive infection strategy.

  17. Profiles of Everyday Thought Suppression

    OpenAIRE

    Ie, Amanda Yen Lin

    2014-01-01

    The present research assessed whether levels of depression, anxiety and worry, obsessive-compulsive distress, and psychopathy were differentially related to distinct thought suppression profiles. As a means to achieving this goal, the Profiles of Everyday Thought Suppression (PETS) scale was constructed to measure the frequencies with which various target thoughts are suppressed. The PETS scale demonstrated good internal consistency and test-retest reliability, and scores were positively co...

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  19. Deconstructing host-pathogen interactions in Drosophila

    Directory of Open Access Journals (Sweden)

    Ethan Bier

    2012-01-01

    Full Text Available Many of the cellular mechanisms underlying host responses to pathogens have been well conserved during evolution. As a result, Drosophila can be used to deconstruct many of the key events in host-pathogen interactions by using a wealth of well-developed molecular and genetic tools. In this review, we aim to emphasize the great leverage provided by the suite of genomic and classical genetic approaches available in flies for decoding details of host-pathogen interactions; these findings can then be applied to studies in higher organisms. We first briefly summarize the general strategies by which Drosophila resists and responds to pathogens. We then focus on how recently developed genome-wide RNA interference (RNAi screens conducted in cells and flies, combined with classical genetic methods, have provided molecular insight into host-pathogen interactions, covering examples of bacteria, fungi and viruses. Finally, we discuss novel strategies for how flies can be used as a tool to examine how specific isolated virulence factors act on an intact host.

  20. The smell of love in Drosophila

    Directory of Open Access Journals (Sweden)

    Anna B. eZiegler

    2013-04-01

    Full Text Available Odors are key sensory signals for social communication and food search in animals including insects. Drosophila melanogaster, is a powerful neurogenetic model commonly used to reveal molecular and cellular mechanisms involved in odorant detection. Males use olfaction together with other sensory modalities to find their mates. Here, we review known olfactory signals, their related olfactory receptors, and the corresponding neuronal architecture impacting courtship. OR67d receptor detects 11-cis-Vaccenyl Acetate (cVA, a male specific pheromone transferred to the female during copulation. Transferred cVA is able to reduce female attractiveness for other males after mating, and is also suspected to decrease male-male courtship. cVA can also serve as an aggregation signal, maybe through another OR. OR47b was shown to be activated by fly odors, and to enhance courtship depending on taste pheromones. IR84a detects phenylacetic acid (PAA and phenylacetaldehyde. These two odors are not pheromones produced by flies, but are present in various fly food sources. PAA enhances male courtship, acting as a food aphrodisiac. Drosophila males have thus developed complementary olfactory strategies to help them to select their mates.

  1. Behavioural reproductive isolation and speciation in Drosophila

    Indian Academy of Sciences (India)

    Punita Nanda; Bashisth Narayan Singh

    2012-06-01

    The origin of premating reproductive isolation continues to help elucidate the process of speciation and is the central event in the evolution of biological species. Therefore, during the process of species formation the diverging populations must acquire some means of reproductive isolation so that the genes from one gene pool are prevented from dispersing freely into a foreign gene pool. In the genus Drosophila, the phenomenon of behavioural reproductive isolation, which is an important type of premating (prezygotic) reproductive isolating mechanisms, has been extensively studied and interesting data have been documented. In many cases incomplete sexual isolation has been observed and the pattern and degree of isolation within and between the species have often been used to elucidate the phylogenetic relationships. The present review documents an overview of speciation mediated through behavioural incompatibility in different species groups of Drosophila with particular reference to the models proposed on the basis of one-sided ethological isolation to predict the direction of evolution. This study is crucial for understanding the mechanism of speciation through behavioural incompatibility and also for an understanding of speciation genetics in future prospects.

  2. Logical modelling of Drosophila signalling pathways.

    Science.gov (United States)

    Mbodj, Abibatou; Junion, Guillaume; Brun, Christine; Furlong, Eileen E M; Thieffry, Denis

    2013-09-01

    A limited number of signalling pathways are involved in the specification of cell fate during the development of all animals. Several of these pathways were originally identified in Drosophila. To clarify their roles, and possible cross-talk, we have built a logical model for the nine key signalling pathways recurrently used in metazoan development. In each case, we considered the associated ligands, receptors, signal transducers, modulators, and transcription factors reported in the literature. Implemented using the logical modelling software GINsim, the resulting models qualitatively recapitulate the main characteristics of each pathway, in wild type as well as in various mutant situations (e.g. loss-of-function or gain-of-function). These models constitute pluggable modules that can be used to assemble comprehensive models of complex developmental processes. Moreover, these models of Drosophila pathways could serve as scaffolds for more complicated models of orthologous mammalian pathways. Comprehensive model annotations and GINsim files are provided for each of the nine considered pathways.

  3. Quantification of food intake in Drosophila.

    Directory of Open Access Journals (Sweden)

    Richard Wong

    Full Text Available Measurement of food intake in the fruit fly Drosophila melanogaster is often necessary for studies of behaviour, nutrition and drug administration. There is no reliable and agreed method for measuring food intake of flies in undisturbed, steady state, and normal culture conditions. We report such a method, based on measurement of feeding frequency by proboscis-extension, validated by short-term measurements of food dye intake. We used the method to demonstrate that (a female flies feed more frequently than males, (b flies feed more often when housed in larger groups and (c fly feeding varies at different times of the day. We also show that alterations in food intake are not induced by dietary restriction or by a null mutation of the fly insulin receptor substrate chico. In contrast, mutation of takeout increases food intake by increasing feeding frequency while mutation of ovo(D increases food intake by increasing the volume of food consumed per proboscis-extension. This approach provides a practical and reliable method for quantification of food intake in Drosophila under normal, undisturbed culture conditions.

  4. Fascin regulates nuclear actin during Drosophila oogenesis.

    Science.gov (United States)

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

    2016-10-01

    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.

  5. Egg-laying rhythm in Drosophila melanogaster

    Indian Academy of Sciences (India)

    T. Manjunatha; Shantala Hari Dass; Vijay Kumar Sharma

    2008-12-01

    Extensive research has been carried out to understand how circadian clocks regulate various physiological processes in organisms. The discovery of clock genes and the molecular clockwork has helped researchers to understand the possible role of these genes in regulating various metabolic processes. In Drosophila melanogaster, many studies have shown that the basic architecture of circadian clocks is multi-oscillatory. In nature, different neuronal subgroups in the brain of D. melanogaster have been demonstrated to control different circadian behavioural rhythms or different aspects of the same circadian rhythm. Among the circadian phenomena that have been studied so far in Drosophila, the egg-laying rhythm is unique, and relatively less explored. Unlike most other circadian rhythms, the egg-laying rhythm is rhythmic under constant light conditions, and the endogenous or free-running period of the rhythm is greater than those of most other rhythms. Although the clock genes and neurons required for the persistence of adult emergence and activity/rest rhythms have been studied extensively, those underlying the circadian egg-laying rhythm still remain largely unknown. In this review, we discuss our current understanding of the circadian egg-laying rhythm in D. melanogaster, and the possible molecular and physiological mechanisms that control the rhythmic output of the egg-laying process.

  6. Drosophila roadblock and Chlamydomonas Lc7

    Science.gov (United States)

    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

  7. The complexity of Drosophila innate immunity

    Directory of Open Access Journals (Sweden)

    A Reumer

    2010-01-01

    Full Text Available Metazoans rely on efficient mechanisms to oppose infections caused by pathogens. The immediate and first-line defense mechanism(s in metazoans, referred to as the innate immune system, is initiated upon recognition of microbial intruders by germline encoded receptors and is executed by a set of rapid effector mechanisms. Adaptive immunity is restricted to vertebrate species and it is controlled and assisted by the innate immune system.Interestingly, most of the basic signaling cascades that regulate the primeval innate defense mechanism(s have been well conserved during evolution, for instance between humans and the fruit fly, Drosophila melanogaster. Being devoid of adaptive signaling and effector systems, Drosophila has become an established model system for studying pristine innate immune cascades and reactions. In general, an immune response is evoked when microorganisms pass the fruit fly’s physical barriers (e.g., cuticle, epithelial lining of gut and trachea, and it is mainly executed in the hemolymph, the equivalent of the mammalian blood. Innate immunity in the fruit fly consists of a phenoloxidase (PO response, a cellular response (hemocytes, an antiviral response, and the NF-κB dependent production of antimicrobial peptides referred to as the humoral response. The JAK/STAT and Jun kinase signaling cascades are also implicated in the defence against pathogens.

  8. The dominant mutation Suppressor of black indicates that de novo pyrimindine biosynthesis is involved in the Drosophila tan pigmentation pathway

    DEFF Research Database (Denmark)

    Piskur, Jure; Kolbak, D.; Søndergaard, Leif;

    1993-01-01

    Pyrimidines, beta-alanine, cuticle, drosophila, pyrimidine analogs, molecular genetics, rudimentary......Pyrimidines, beta-alanine, cuticle, drosophila, pyrimidine analogs, molecular genetics, rudimentary...

  9. Functional Gustatory Role of Chemoreceptors in Drosophila Wings.

    Science.gov (United States)

    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. PMID:27160896

  10. Functional Gustatory Role of Chemoreceptors in Drosophila Wings.

    Science.gov (United States)

    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.

  11. Correction: Serendipitous discovery of Wolbachia genomes in multiple Drosophila species

    OpenAIRE

    Salzberg, Steven L.; Julie C Dunning Hotopp; Delcher, Arthur L; Pop, Mihai; Smith, Douglas R; Eisen, Michael B; Nelson, William C.

    2005-01-01

    A correction to Serendipitous discovery of Wolbachia genomes in multiple Drosophila species by SL Salzberg, JC Dunning Hotopp, AL Delcher, M Pop, DR Smith, MB Eisen and WC Nelson. Genome Biology 2005, 6:R23

  12. Is premating isolation in Drosophila overestimated due to uncontrolled factors?

    Indian Academy of Sciences (India)

    Pelayo Casares; Rafael Piñeiro; Maria C. Carracedo

    2005-12-01

    Sexual isolation in Drosophila is typically measured by multiple-choice mating tests. While many environmental variables during such tests are controlled by the researcher, there are some factors that are usually uncontrolled. We demonstrate, using Drosophila melanogaster and D. pseudoobscura flies, that the temperature of rearing, preadult density, and level of consanguinity, can all produce differences in mating propensity between genetically equivalent flies. These differences in mating propensity, in turn, can give rise to statistically significant results in multiple-choice mating tests, leading to positive isolation values and the artifactual inference of sexual isolation between populations. This fact agrees with a nonrandom excess of significant positive tests found in a review of the literature of Drosophila intraspecific mating choice. An overestimate of true cases of sexual isolation in Drosophila in the literature can, therefore, not be ruled out.

  13. Molecular evolution of a Drosophila homolog of human BRCA2.

    Science.gov (United States)

    Bennett, Sarah M; Noor, Mohamed A F

    2009-11-01

    The human cancer susceptibility gene, BRCA2, functions in double-strand break repair by homologous recombination, and it appears to function via interaction of a repetitive region ("BRC repeats") with RAD-51. A putatively simpler homolog, dmbrca2, was identified in Drosophila melanogaster recently and also affects mitotic and meiotic double-strand break repair. In this study, we examined patterns of repeat variation both within Drosophila pseudoobscura and among available Drosophila genome sequences. We identified extensive variation within and among closely related Drosophila species in BRC repeat number, to the extent that variation within this genus recapitulates the extent of variation found across the entire animal kingdom. We describe patterns of evolution across species by documenting recent repeat expansions (sometimes in tandem arrays) and homogenizations within available genome sequences. Overall, we have documented patterns and modes of evolution in a new model system of a gene which is important to human health.

  14. An Alternative to Thought Suppression?

    Science.gov (United States)

    Boice, Robert

    2012-01-01

    Comments on the original article, "Setting free the bears: Escape from thought suppression," by D. M. Wegner (see record 2011-25622-008). While Wegner supposed that we might have to learn to live with bad thoughts, the present author discusses the use of imagination and guided imagery as an alternative to forced thought suppression.

  15. Visual surround suppression in schizophrenia

    Directory of Open Access Journals (Sweden)

    Marc Samuel Tibber

    2013-02-01

    Full Text Available Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with schizophrenia demonstrated weaker surround suppression compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation surround suppression in schizophrenia may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies.

  16. Inducing amnesia through systemic suppression.

    Science.gov (United States)

    Hulbert, Justin C; Henson, Richard N; Anderson, Michael C

    2016-01-01

    Hippocampal damage profoundly disrupts the ability to store new memories of life events. Amnesic windows might also occur in healthy people due to disturbed hippocampal function arising during mental processes that systemically reduce hippocampal activity. Intentionally suppressing memory retrieval (retrieval stopping) reduces hippocampal activity via control mechanisms mediated by the lateral prefrontal cortex. Here we show that when people suppress retrieval given a reminder of an unwanted memory, they are considerably more likely to forget unrelated experiences from periods surrounding suppression. This amnesic shadow follows a dose-response function, becomes more pronounced after practice suppressing retrieval, exhibits characteristics indicating disturbed hippocampal function, and is predicted by reduced hippocampal activity. These findings indicate that stopping retrieval engages a suppression mechanism that broadly compromises hippocampal processes and that hippocampal stabilization processes can be interrupted strategically. Cognitively triggered amnesia constitutes an unrecognized forgetting process that may account for otherwise unexplained memory lapses following trauma. PMID:26977589

  17. Bazooka mediates secondary axon morphology in Drosophila brain lineages

    OpenAIRE

    Hartenstein Volker; Spindler Shana R

    2011-01-01

    Abstract In the Drosophila brain, neural lineages project bundled axon tracts into a central neuropile. Each lineage exhibits a stereotypical branching pattern and trajectory, which distinguish it from other lineages. In this study, we used a multilineage approach to explore the neural function of the Par-complex member Par3/Bazooka in vivo. Drosophila bazooka is expressed in post-mitotic neurons of the larval brain and localizes within neurons in a lineage-dependent manner. The fact that mul...

  18. A development-based compartmentalization of the Drosophila central brain

    OpenAIRE

    Pereanu, Wayne; Kumar, Abilasha; Jennett, Arnim; Reichert, Heinrich; Hartenstein, Volker

    2010-01-01

    The neuropile of the Drosophila brain is subdivided into anatomically discrete compartments. Compartments are rich in terminal neurite branching and synapses; they are the neuropile domains in which signal processing takes place. Compartment boundaries are defined by more or less dense layers of glial cells, as well as long neurite fascicles. These fascicles are formed during the larval period when the approximately 100 neuronal lineages that constitute the Drosophila central brain differenti...

  19. Functional gustatory role of chemoreceptors in drosophila wings

    OpenAIRE

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

    2016-01-01

    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 Ca2+ levels. Conversely, genetically modified flies presenting a wing-specific reductio...

  20. Circadian Organization of Behavior and Physiology in Drosophila

    OpenAIRE

    Allada, Ravi; Chung, Brian Y.

    2010-01-01

    Circadian clocks organize behavior and physiology to adapt to daily environmental cycles. Genetic approaches in the fruit fly, Drosophila melanogaster, have revealed widely conserved molecular gears of these 24-h timers. Yet much less is known about how these cell-autonomous clocks confer temporal information to modulate cellular functions. Here we discuss our current knowledge of circadian clock function in Drosophila, providing an overview of the molecular underpinnings of circadian clocks....

  1. FlyBase: a Drosophila database. Flybase Consortium.

    OpenAIRE

    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.

  2. Dietary glucose regulates yeast consumption in adult Drosophila males

    OpenAIRE

    Sebastien eLebreton; Peter eWitzgall; Marie eOlsson; Becher, Paul G.

    2014-01-01

    The adjustment of feeding behavior in response to hunger and satiety contributes to homeostatic regulation in animals. The fruit fly Drosophila melanogaster feeds on yeasts growing on overripe fruit, providing nutrients required for adult survival, reproduction and larval growth. Here, we present data on how the nutritional value of food affects subsequent yeast consumption in Drosophila adult males. After a period of starvation, flies showed intensive yeast consumption. In comparison, flies ...

  3. Candidate Glutamatergic Neurons in the Visual System of Drosophila

    OpenAIRE

    Shamprasad Varija Raghu; Alexander Borst

    2011-01-01

    The visual system of Drosophila contains approximately 60,000 neurons that are organized in parallel, retinotopically arranged columns. A large number of these neurons have been characterized in great anatomical detail. However, studies providing direct evidence for synaptic signaling and the neurotransmitter used by individual neurons are relatively sparse. Here we present a first layout of neurons in the Drosophila visual system that likely release glutamate as their major neurotransmitter....

  4. Evolution of Drosophila ribosomal protein gene core promoters

    OpenAIRE

    Ma, Xiaotu; Zhang, Kangyu; Li, Xiaoman

    2008-01-01

    The coordinated expression of ribosomal protein genes (RPGs) has been well documented in many species. Previous analyses of RPG promoters focus only on Fungi and mammals. Recognizing this gap and using a comparative genomics approach, we utilize a motif-finding algorithm that incorporates cross-species conservation to identify several significant motifs in Drosophila RPG promoters. As a result, significant differences of the enriched motifs in RPG promoter are found among Drosophila, Fungi, a...

  5. Following the Motion of Polycomb Bodies in Living Drosophila Embryos.

    Science.gov (United States)

    Cheutin, Thierry; Cavalli, Giacomo

    2016-01-01

    During the last two decades, observation of cell nuclei in live microscopy evidences motion of nuclear compartments. Drosophila embryos constitute a good model to study nuclear dynamic during cell differentiation because they can easily be observed in live microscopy. Inside the cell nucleus, Polycomb group proteins accumulate in foci named Pc bodies. Here, we describe a method to visualize and analyze the motion of these nuclear compartments inside cell nuclei of Drosophila embryos. PMID:27659993

  6. Genomic and karyotypic variation in Drosophila parasitoids (Hymenoptera, Cynipoidea, Figitidae

    Directory of Open Access Journals (Sweden)

    Vladimir Gokhman

    2011-08-01

    Full Text Available Drosophila melanogaster Meigen, 1830 has served as a model insect for over a century. Sequencing of the 11 additional Drosophila Fallen, 1823 species marks substantial progress in comparative genomics of this genus. By comparison, practically nothing is known about the genome size or genome sequences of parasitic wasps of Drosophila. Here, we present the first comparative analysis of genome size and karyotype structures of Drosophila parasitoids of the Leptopilina Förster, 1869 and Ganaspis Förster, 1869 species. The gametic genome size of Ganaspis xanthopoda (Ashmead, 1896 is larger than those of the three Leptopilina species studied. The genome sizes of all parasitic wasps studied here are also larger than those known for all Drosophila species. Surprisingly, genome sizes of these Drosophila parasitoids exceed the average value known for all previously studied Hymenoptera. The haploid chromosome number of both Leptopilina heterotoma (Thomson, 1862 and L. victoriae Nordlander, 1980 is ten. A chromosomal fusion appears to have produced a distinct karyotype for L. boulardi (Barbotin, Carton et Keiner-Pillault, 1979 (n = 9, whose genome size is smaller than that of wasps of the L. heterotoma clade. Like L. boulardi, the haploid chromosome number for G. xanthopoda is also nine. Our studies reveal a positive, but non linear, correlation between the genome size and total chromosome length in Drosophila parasitoids. These Drosophila parasitoids differ widely in their host range, and utilize different infection strategies to overcome host defense. Their comparative genomics, in relation to their exceptionally well-characterized hosts, will prove to be valuable for understanding the molecular basis of the host-parasite arms race and how such mechanisms shape the genetic structures of insect communities.

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

    Directory of Open Access Journals (Sweden)

    James Angus Chandler

    2014-07-01

    Full Text Available 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.

  8. Simulation of gene pyramiding in Drosophila melanogaster

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Gene pyramiding has been successfully practiced in plant breeding for developing new breeds or lines in which favorable genes from several different lines were integrated.But it has not been used in animal breeding,and some theoretical investigation and simulation analysis with respect to its strategies,feasibility and efficiency are needed before it can be implemented in animals.In this study,we used four different pure fines of Drosophila melanogaster,each of which is homozygous at a specific mutant gene with a visible effect on phenotype,to simulate the gene pyramiding process and analyze the duration and population size required in different pyramiding strategies.We finally got the ideal individuals,which are homozygous at the four target genes simultaneously.This study demonstrates that gene pyramiding is feasible in animal breeding and the interaction between genes may affect the final results.

  9. Innate immunity in Drosophila: Pathogens and pathways

    Institute of Scientific and Technical Information of China (English)

    Shubha Govind

    2008-01-01

    Following in the footsteps of traditional developmental genetics, research over the last 15 years has shown that innate immunity against bacteria and fungi is governed largely by two NF-κB signal transduction pathways, Toll and IMD. Antiviral immunity appears to stem from RNA interference, whereas resistance against parasitoids is conferred by Toll signaling. The identification of these post-transcriptional regulatory mechanisms and the annotation of most Drosophila immunity genes have derived from functional genomic studies using "model" pathogens, intact animals and cell lines. The D. melanogaster host has thus provided the core information that can be used to study responses to natural microbial and metazoan pathogens as they become identified, as well as to test ideas of selection and evolutionary change. These analyses are of general importance to understanding mechanisms of other insect host-pathogen interactions and determinants of variation in host resistance.

  10. A Protein Interaction Map of Drosophila melanogaster

    Science.gov (United States)

    Giot, L.; Bader, J. S.; Brouwer, C.; Chaudhuri, A.; Kuang, B.; Li, Y.; Hao, Y. L.; Ooi, C. E.; Godwin, B.; Vitols, E.; Vijayadamodar, G.; Pochart, P.; Machineni, H.; Welsh, M.; Kong, Y.; Zerhusen, B.; Malcolm, R.; Varrone, Z.; Collis, A.; Minto, M.; Burgess, S.; McDaniel, L.; Stimpson, E.; Spriggs, F.; Williams, J.; Neurath, K.; Ioime, N.; Agee, M.; Voss, E.; Furtak, K.; Renzulli, R.; Aanensen, N.; Carrolla, S.; Bickelhaupt, E.; Lazovatsky, Y.; DaSilva, A.; Zhong, J.; Stanyon, C. A.; Finley, R. L.; White, K. P.; Braverman, M.; Jarvie, T.; Gold, S.; Leach, M.; Knight, J.; Shimkets, R. A.; McKenna, M. P.; Chant, J.; Rothberg, J. M.

    2003-12-01

    Drosophila melanogaster is a proven model system for many aspects of human biology. Here we present a two-hybrid-based protein-interaction map of the fly proteome. A total of 10,623 predicted transcripts were isolated and screened against standard and normalized complementary DNA libraries to produce a draft map of 7048 proteins and 20,405 interactions. A computational method of rating two-hybrid interaction confidence was developed to refine this draft map to a higher confidence map of 4679 proteins and 4780 interactions. Statistical modeling of the network showed two levels of organization: a short-range organization, presumably corresponding to multiprotein complexes, and a more global organization, presumably corresponding to intercomplex connections. The network recapitulated known pathways, extended pathways, and uncovered previously unknown pathway components. This map serves as a starting point for a systems biology modeling of multicellular organisms, including humans.

  11. Optogenetic Control of Gene Expression in Drosophila.

    Directory of Open Access Journals (Sweden)

    Yick-Bun Chan

    Full Text Available To study the molecular mechanism of complex biological systems, it is important to be able to artificially manipulate gene expression in desired target sites with high precision. Based on the light dependent binding of cryptochrome 2 and a cryptochrome interacting bHLH protein, we developed a split lexA transcriptional activation system for use in Drosophila that allows regulation of gene expression in vivo using blue light or two-photon excitation. We show that this system offers high spatiotemporal resolution by inducing gene expression in tissues at various developmental stages. In combination with two-photon excitation, gene expression can be manipulated at precise sites in embryos, potentially offering an important tool with which to examine developmental processes.

  12. Quantitative neuroanatomy for connectomics in Drosophila.

    Science.gov (United States)

    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. PMID:26990779

  13. Gustatory processing and taste memory in Drosophila.

    Science.gov (United States)

    Masek, Pavel; Keene, Alex C

    2016-06-01

    Taste allows animals to discriminate the value and potential toxicity of food prior to ingestion. Many tastants elicit an innate attractive or avoidance response that is modifiable with nutritional state and prior experience. A powerful genetic tool kit, well-characterized gustatory system, and standardized behavioral assays make the fruit fly, Drosophila melanogaster, an excellent system for investigating taste processing and memory. Recent studies have used this system to identify the neural basis for acquired taste preference. These studies have revealed a role for dopamine-mediated plasticity of the mushroom bodies that modulate the threshold of response to appetitive tastants. The identification of neural circuitry regulating taste memory provides a system to study the genetic and physiological processes that govern plasticity within a defined memory circuit. PMID:27328844

  14. Antioxidants, metabolic rate and aging in Drosophila

    Science.gov (United States)

    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.

  15. Structure and Development of Glia in Drosophila

    Science.gov (United States)

    Hartenstein, Volker

    2014-01-01

    Insect glia represents a conspicuous and diverse population of cells and plays a role in controlling neuronal progenitor proliferation, axonal growth, neuronal differentiation and maintenance, and neuronal function. Genetic studies in Drosophila have elucidated many aspects of glial structure, function and development. Just as in vertebrates, it appears as if different classes of glial cells are specialized for different functions. Based on topology and cell shape, glial cells of the central nervous system fall into three classes (Fig. 1A–C): (i) surface glia that extend sheath-like processes to wrap around the entire brain; (ii) cortex glia (also called cell body-associated glia) that encapsulate neuronal somata and neuroblasts which form the outer layer (cortex) of the central nervous system; (iii) neuropile glia that are located at the interface between the cortex and the neuropile, the central domain of the nervous system formed by the highly branched neuronal processes and their synaptic contacts. Surface glia is further subdivided into an outer, perineurial layer, and an inner, subperineurial layer. Likewise, neuropile glia comprises a class of cells that remain at the surface of the neuropile (ensheathing glia), and a second class that forms profuse lamellar processes around nerve fibers within the neuropile (astrocyte-like or reticular glia). Glia also surrounds the peripheral nerves and sensory organs; here, one also recognizes perineurial and subperineurial glia, and a third type called “wrapping glia” that most likely corresponds to the ensheathing glia of the central nervous system. Much more experimental work is needed to determine how fundamental these differences between classes of glial cells are, or how and when during development they are specified. To aid in this work the following review will briefly summarize our knowledge of the classes of glial cells encountered in the Drosophila nervous system, and then survey their development from

  16. Isolation and characterization of acetylcholinesterase from Drosophila.

    Science.gov (United States)

    Gnagey, A L; Forte, M; Rosenberry, T L

    1987-09-25

    The purification and characterization of acetylcholinesterase from heads of the fruit fly Drosophila are described. Sequential extraction procedures indicated that approximately 40% of the activity was soluble and 60% membrane-bound and that virtually none (less than 4%) corresponded to collagen-tailed forms. The membrane-bound enzyme was extracted with Triton X-100 and purified over 4000-fold by affinity chromatography on acridinium resin. Hydrodynamic analysis by both sucrose gradient centrifugation and chromatography on Sepharose CL-4B revealed an Mr of 165,000 similar to that observed for dimeric (G2) forms of the enzyme in mammalian tissues. In contrast, the purified enzyme gave predominant bands of about 100 kDa prior to disulfied reduction and 55 kDa after reduction on polyacrylamide gel electrophoresis in sodium dodecyl sulfate, values that are significantly lower than those reported for purified G2 enzymes from other species. However, the presence of a faint band at 70 kDa which could be labeled by [3H]diisopropyl fluorophosphate prior to denaturation suggested that the 55-kDa band as well as a 16-kDa species arose from proteolysis. This was confirmed by reductive radiomethylation and amine analysis of the 70-, 55-, and 16-kDa bands. All three contained ethanolamine and glucosamine residues that are characteristic of a C-terminal glycolipid anchor in other G2 acetylcholinesterases. The catalytic properties of the enzyme were examined by titration with a fluorogenic reagent which revealed a turnover number for acetylthiocholine that was 6-fold lower than eel and 3-fold lower than human erythrocyte acetylcholinesterase. Furthermore, the Drosophila enzyme hydrolyzed butyrylthiocholine much more efficiently than these eel or human enzymes, an indication that the fly head enzyme has a substrate specificity intermediate between mammalian acetylcholinesterases and butyrylcholinesterases.

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

    Science.gov (United States)

    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

  18. Chloride channels in the plasma membrane of a foetal Drosophila cell line, S2

    DEFF Research Database (Denmark)

    Asmild, Margit; Willumsen, Niels J.

    2000-01-01

    S2 cells, Cl- Channels, Expression system, Drosophila, Inward rectifier, Outward rectifier, Patch clamp......S2 cells, Cl- Channels, Expression system, Drosophila, Inward rectifier, Outward rectifier, Patch clamp...

  19. The NADPH metabolic network regulates human αB-crystallin cardiomyopathy and reductive stress in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Heng B Xie

    2013-06-01

    Full Text Available Dominant mutations in the alpha-B crystallin (CryAB gene are responsible for a number of inherited human disorders, including cardiomyopathy, skeletal muscle myopathy, and cataracts. The cellular mechanisms of disease pathology for these disorders are not well understood. Among recent advances is that the disease state can be linked to a disturbance in the oxidation/reduction environment of the cell. In a mouse model, cardiomyopathy caused by the dominant CryAB(R120G missense mutation was suppressed by mutation of the gene that encodes glucose 6-phosphate dehydrogenase (G6PD, one of the cell's primary sources of reducing equivalents in the form of NADPH. Here, we report the development of a Drosophila model for cellular dysfunction caused by this CryAB mutation. With this model, we confirmed the link between G6PD and mutant CryAB pathology by finding that reduction of G6PD expression suppressed the phenotype while overexpression enhanced it. Moreover, we find that expression of mutant CryAB in the Drosophila heart impaired cardiac function and increased heart tube dimensions, similar to the effects produced in mice and humans, and that reduction of G6PD ameliorated these effects. Finally, to determine whether CryAB pathology responds generally to NADPH levels we tested mutants or RNAi-mediated knockdowns of phosphogluconate dehydrogenase (PGD, isocitrate dehydrogenase (IDH, and malic enzyme (MEN, the other major enzymatic sources of NADPH, and we found that all are capable of suppressing CryAB(R120G pathology, confirming the link between NADP/H metabolism and CryAB.

  20. The NADPH metabolic network regulates human αB-crystallin cardiomyopathy and reductive stress in Drosophila melanogaster.

    Science.gov (United States)

    Xie, Heng B; Cammarato, Anthony; Rajasekaran, Namakkal S; Zhang, Huali; Suggs, Jennifer A; Lin, Ho-Chen; Bernstein, Sanford I; Benjamin, Ivor J; Golic, Kent G

    2013-06-01

    Dominant mutations in the alpha-B crystallin (CryAB) gene are responsible for a number of inherited human disorders, including cardiomyopathy, skeletal muscle myopathy, and cataracts. The cellular mechanisms of disease pathology for these disorders are not well understood. Among recent advances is that the disease state can be linked to a disturbance in the oxidation/reduction environment of the cell. In a mouse model, cardiomyopathy caused by the dominant CryAB(R120G) missense mutation was suppressed by mutation of the gene that encodes glucose 6-phosphate dehydrogenase (G6PD), one of the cell's primary sources of reducing equivalents in the form of NADPH. Here, we report the development of a Drosophila model for cellular dysfunction caused by this CryAB mutation. With this model, we confirmed the link between G6PD and mutant CryAB pathology by finding that reduction of G6PD expression suppressed the phenotype while overexpression enhanced it. Moreover, we find that expression of mutant CryAB in the Drosophila heart impaired cardiac function and increased heart tube dimensions, similar to the effects produced in mice and humans, and that reduction of G6PD ameliorated these effects. Finally, to determine whether CryAB pathology responds generally to NADPH levels we tested mutants or RNAi-mediated knockdowns of phosphogluconate dehydrogenase (PGD), isocitrate dehydrogenase (IDH), and malic enzyme (MEN), the other major enzymatic sources of NADPH, and we found that all are capable of suppressing CryAB(R120G) pathology, confirming the link between NADP/H metabolism and CryAB.

  1. Genetic link between Cabeza, a Drosophila homologue of Fused in Sarcoma (FUS), and the EGFR signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Shimamura, Mai; Kyotani, Akane [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Azuma, Yumiko [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Yoshida, Hideki; Binh Nguyen, Thanh [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Mizuta, Ikuko; Yoshida, Tomokatsu; Mizuno, Toshiki [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Nakagawa, Masanori [North Medical Center, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566 (Japan); Tokuda, Takahiko, E-mail: ttokuda@koto.kpu-m.ac.jp [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Department of Molecular Pathobiology of Brain Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566 (Japan); Yamaguchi, Masamitsu, E-mail: myamaguc@kit.ac.jp [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan)

    2014-08-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that causes progressive muscular weakness. Fused in Sarcoma (FUS) that has been identified in familial ALS is an RNA binding protein that is normally localized in the nucleus. However, its function in vivo is not fully understood. Drosophila has Cabeza (Caz) as a FUS homologue and specific knockdown of Caz in the eye imaginal disc and pupal retina using a GMR-GAL4 driver was here found to induce an abnormal morphology of the adult compound eyes, a rough eye phenotype. This was partially suppressed by expression of the apoptosis inhibitor P35. Knockdown of Caz exerted no apparent effect on differentiation of photoreceptor cells. However, immunostaining with an antibody to Cut that marks cone cells revealed fusion of these and ommatidia of pupal retinae. These results indicate that Caz knockdown induces apoptosis and also inhibits differentiation of cone cells, resulting in abnormal eye morphology in adults. Mutation in EGFR pathway-related genes, such as rhomboid-1, rhomboid-3 and mirror suppressed the rough eye phenotype induced by Caz knockdown. Moreover, the rhomboid-1 mutation rescued the fusion of cone cells and ommatidia observed in Caz knockdown flies. The results suggest that Caz negatively regulates the EGFR signaling pathway required for determination of cone cell fate in Drosophila. - Highlights: • Knockdown of Cabeza induced rough eye phenotype. • Knockdown of Cabeza induced fusion of cone cells in pupal retinae. • Knockdown of Cabeza induced apoptosis in pupal retinae. • Mutation in EGFR pathway-related genes suppressed the rough eye phenotype. • Cabeza may negatively regulate the EGFR pathway.

  2. Mutations in ash1 and trx enhance P-element-dependent silencing in Drosophila melanogaster.

    Science.gov (United States)

    McCracken, Allen; Locke, John

    2016-08-01

    In Drosophila melanogaster, the mini-w(+) transgene in Pci is normally expressed throughout the adult eye; however, when other P or KP elements are present, a variegated-eye phenotype results, indicating random w(+) silencing during development called P-element-dependent silencing (PDS). Mutant Su(var)205 and Su(var)3-7 alleles act as haplo-suppressors/triplo-enhancers of this variegated phenotype, indicating that these heterochromatic modifiers act dose dependently in PDS. Previously, we recovered a spontaneous mutation of P{lacW}ci(Dplac) called P{lacW}ci(DplacE1) (E1) that variegated in the absence of P elements, presumably due to the insertion of an adjacent gypsy element. From a screen for genetic modifiers of E1 variegation, we describe here the isolation of five mutations in ash1 and three in trx that enhance the E1 variegated phenotype in a dose-dependent and cumulative manner. These mutant alleles enhance PDS at E1, and in E1/P{lacW}ci(Dplac), but suppress position effect variegation (PEV) at In(1)w(m)(4). This opposite action is consistent with a model where ASH1 and TRX mark transcriptionally active chromatin domains. If ASH1 or TRX function is lost or reduced, heterochromatin can spread into these domains creating a sink that diverts heterochromatic proteins from other variegating locations, which then may express a suppressed phenotype. PMID:27373142

  3. Disruption of insulin signalling affects the neuroendocrine stress reaction in Drosophila females.

    Science.gov (United States)

    Rauschenbach, Inga Y; Karpova, Evgenia K; Adonyeva, Natalya V; Andreenkova, Olga V; Faddeeva, Natalya V; Burdina, Elena V; Alekseev, Alexander A; Menshanov, Petr N; Gruntenko, Nataly E

    2014-10-15

    Juvenile hormone (JH) and dopamine are involved in the stress response in insects. The insulin/insulin-like growth factor signalling pathway has also recently been found to be involved in the regulation of various processes, including stress tolerance. However, the relationships between the JH, dopamine and insulin signalling pathways remain unclear. Here, we study the role of insulin signalling in the regulation of JH and dopamine metabolism under normal and heat stress conditions in Drosophila melanogaster females. We show that suppression of the insulin-like receptor (InR) in the corpus allatum, a specialised endocrine gland that synthesises JH, causes an increase in dopamine level and JH-hydrolysing activity and alters the activities of enzymes that produce as well as those that degrade dopamine [alkaline phosphatase (ALP), tyrosine hydroxylase (TH) and dopamine-dependent arylalkylamine N-acetyltransferase (DAT)]. We also found that InR suppression in the corpus allatum modulates dopamine, ALP, TH and JH-hydrolysing activity in response to heat stress and that it decreases the fecundity of the flies. JH application restores dopamine metabolism and fecundity in females with decreased InR expression in the corpus allatum. Our data provide evidence that the insulin/insulin-like growth factor signalling pathway regulates dopamine metabolism in females of D. melanogaster via the system of JH metabolism and that it affects the development of the neuroendocrine stress reaction and interacts with JH in the control of reproduction in this species.

  4. Drosophila Spidey/Kar Regulates Oenocyte Growth via PI3-Kinase Signaling.

    Science.gov (United States)

    Cinnamon, Einat; Makki, Rami; Sawala, Annick; Wickenberg, Leah P; Blomquist, Gary J; Tittiger, Claus; Paroush, Ze'ev; Gould, Alex P

    2016-08-01

    Cell growth and proliferation depend upon many different aspects of lipid metabolism. One key signaling pathway that is utilized in many different anabolic contexts involves Phosphatidylinositide 3-kinase (PI3K) and its membrane lipid products, the Phosphatidylinositol (3,4,5)-trisphosphates. It remains unclear, however, which other branches of lipid metabolism interact with the PI3K signaling pathway. Here, we focus on specialized fat metabolizing cells in Drosophila called larval oenocytes. In the presence of dietary nutrients, oenocytes undergo PI3K-dependent cell growth and contain very few lipid droplets. In contrast, during starvation, oenocytes decrease PI3K signaling, shut down cell growth and accumulate abundant lipid droplets. We now show that PI3K in larval oenocytes, but not in fat body cells, functions to suppress lipid droplet accumulation. Several enzymes of fatty acid, triglyceride and hydrocarbon metabolism are required in oenocytes primarily for lipid droplet induction rather than for cell growth. In contrast, a very long chain fatty-acyl-CoA reductase (FarO) and a putative lipid dehydrogenase/reductase (Spidey, also known as Kar) not only promote lipid droplet induction but also inhibit oenocyte growth. In the case of Spidey/Kar, we show that the growth suppression mechanism involves inhibition of the PI3K signaling pathway upstream of Akt activity. Together, the findings in this study show how Spidey/Kar and FarO regulate the balance between the cell growth and lipid storage of larval oenocytes. PMID:27500738

  5. Female contact modulates male aggression via a sexually dimorphic GABAergic circuit in Drosophila.

    Science.gov (United States)

    Yuan, Quan; Song, Yuanquan; Yang, Chung-Hui; Jan, Lily Yeh; Jan, Yuh Nung

    2014-01-01

    Intraspecific male-male aggression, which is important for sexual selection, is regulated by environment, experience and internal states through largely undefined molecular and cellular mechanisms. To understand the basic neural pathway underlying the modulation of this innate behavior, we established a behavioral assay in Drosophila melanogaster and investigated the relationship between sexual experience and aggression. In the presence of mating partners, adult male flies exhibited elevated levels of aggression, which was largely suppressed by prior exposure to females via a sexually dimorphic neural mechanism. The suppression involved the ability of male flies to detect females by contact chemosensation through the pheromone-sensing ion channel ppk29 and was mediated by male-specific GABAergic neurons acting on the GABAA receptor RDL in target cells. Silencing or activating this circuit led to dis-inhibition or elimination of sex-related aggression, respectively. We propose that the GABAergic inhibition represents a critical cellular mechanism that enables prior experience to modulate aggression. PMID:24241395

  6. Drosophila ARSs contain the yeast ARS consensus sequence and a replication enhancer.

    OpenAIRE

    Mills, J S; Kingsman, A J; Kingsman, S M

    1986-01-01

    A number of restriction fragments that function as autonomously replicating sequences (ARSs) in yeast have been isolated from Drosophila melanogaster DNA. The behaviour in yeast of plasmids containing Drosophila ARS elements was studied and compared to that exhibited by the archetypal yeast ARS-1 plasmid. ARS functions were localised by subcloning and BAL-31 deletion analysis. These studies demonstrated the structural and functional complexity of Drosophila ARSs. Each Drosophila ARS element h...

  7. FlyBase: a Drosophila database. The FlyBase consortium.

    OpenAIRE

    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; Grey, A; Kaufman, T; Matthews, K.; Gilbert, D

    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 integr...

  8. Cryogenic Acoustic Suppression Testing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project will explore and test the feasibility and effectiveness of using a cryogenic fluid (liquid nitrogen) to facilitate acoustic suppression in a...

  9. The dopaminergic system in the aging brain of Drosophila

    Directory of Open Access Journals (Sweden)

    Katherine E White

    2010-12-01

    Full Text Available Drosophila models of Parkinson’s disease are characterised by two principal phenotypes: the specific loss of dopaminergic 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 analysed the dopaminergic system and motor behavior in aging Drosophila. Dopaminergic 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 dopaminergic 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, dopaminergic 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 dopaminergic behaviors in Drosophila. Moreover, dopaminergic neurons were maintained between early- and late life, as quantified by TH>mCD8::GFP and anti-TH labelling, indicating that adult onset, age-related degeneration of dopaminergic 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 dopaminergic neurons

  10. Thyroid suppression test with dextrothyroxine

    International Nuclear Information System (INIS)

    The classic thyroid suppression test with triiodothyronine (l-T3) has been shown to be efficient as an auxiliary method in the diagnosis of thyroid diseases, but should not be performed on elderly patients or on those with heart disease or a tendency to tachycardia. Since these subjects seem able to support a short period of dextro-thyronine (d-T4) feeding, we compared the effect of d-T4 and l-T3 on the 24 hours thyroid uptake in euthyroid and hyperthyroid subjects. After basal radio-iodine uptake determination, 99 patients without hyperthyroidism and 27 with Graves' disease were randomly divided in 2 groups; one received 100μg of l-T3 per day and the other 4 mg of d-T4 per day, both groups being treated for a period of 10 days. At the end of this suppression period the 24 hours radio-iodine uptake was measured again and the percentual suppression index (S.I.) calculated. Since the comparison of the two groups showed no difference between the suppressive effect of l-T3 and d-T4 in euthyroid subjects, while dextro-thyronine, as levo-triiodothyronine, did not suppress the 24 hours uptake of hyperthyroid patients, l-T3 or d-T4 can be used interchangeably to test thyroid suppressibility. In the euthyroid subjects the normal range for the post-suppression uptake was 0-17.1% and for the suppression index 54,7.100%

  11. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  12. Requirement of matrix metalloproteinase-1 for intestinal homeostasis in the adult Drosophila midgut

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Shin-Hae; Park, Joung-Sun [Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 609-735 (Korea, Republic of); Kim, Young-Shin [Research Institute of Genetic Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Chung, Hae-Young [Molecular Inflammation Research Center for Aging Intervention (MRCA), College of Pharmacy, Pusan National University, Busan 609-735 (Korea, Republic of); Yoo, Mi-Ae, E-mail: mayoo@pusan.ac.kr [Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 609-735 (Korea, Republic of)

    2012-03-10

    Stem cells are tightly regulated by both intrinsic and extrinsic signals as well as the extracellular matrix (ECM) for tissue homeostasis and regenerative capacity. Matrix metalloproteinases (MMPs), proteolytic enzymes, modulate the turnover of numerous substrates, including cytokine precursors, growth factors, and ECM molecules. However, the roles of MMPs in the regulation of adult stem cells are poorly understood. In the present study, we utilize the Drosophila midgut, which is an excellent model system for studying stem cell biology, to show that Mmp1 is involved in the regulation of intestinal stem cells (ISCs). The results showed that Mmp1 is expressed in the adult midgut and that its expression increases with age and with exposure to oxidative stress. Mmp1 knockdown or Timp-overexpressing flies and flies heterozygous for a viable, hypomorphic Mmp1 allele increased ISC proliferation in the gut, as shown by staining with an anti-phospho-histone H3 antibody and BrdU incorporation assays. Reduced Mmp1 levels induced intestinal hyperplasia, and the Mmp1depletion-induced ISC proliferation was rescued by the suppression of the EGFR signaling pathway, suggesting that Mmp1 regulates ISC proliferation through the EGFR signaling pathway. Furthermore, adult gut-specific knockdown and whole-animal heterozygotes of Mmp1 increased additively sensitivity to paraquat-induced oxidative stress and shortened lifespan. Our data suggest that Drosophila Mmp1 is involved in the regulation of ISC proliferation for maintenance of gut homeostasis. -- Highlights: Black-Right-Pointing-Pointer Mmp1 is expressed in the adult midgut. Black-Right-Pointing-Pointer Mmp1 is involved in the regulation of ISC proliferation activity. Black-Right-Pointing-Pointer Mmp1-related ISC proliferation is associated with EGFR signaling. Black-Right-Pointing-Pointer Mmp1 in the gut is required for the intestinal homeostasis and longevity.

  13. Requirement of matrix metalloproteinase-1 for intestinal homeostasis in the adult Drosophila midgut

    International Nuclear Information System (INIS)

    Stem cells are tightly regulated by both intrinsic and extrinsic signals as well as the extracellular matrix (ECM) for tissue homeostasis and regenerative capacity. Matrix metalloproteinases (MMPs), proteolytic enzymes, modulate the turnover of numerous substrates, including cytokine precursors, growth factors, and ECM molecules. However, the roles of MMPs in the regulation of adult stem cells are poorly understood. In the present study, we utilize the Drosophila midgut, which is an excellent model system for studying stem cell biology, to show that Mmp1 is involved in the regulation of intestinal stem cells (ISCs). The results showed that Mmp1 is expressed in the adult midgut and that its expression increases with age and with exposure to oxidative stress. Mmp1 knockdown or Timp-overexpressing flies and flies heterozygous for a viable, hypomorphic Mmp1 allele increased ISC proliferation in the gut, as shown by staining with an anti-phospho-histone H3 antibody and BrdU incorporation assays. Reduced Mmp1 levels induced intestinal hyperplasia, and the Mmp1depletion-induced ISC proliferation was rescued by the suppression of the EGFR signaling pathway, suggesting that Mmp1 regulates ISC proliferation through the EGFR signaling pathway. Furthermore, adult gut-specific knockdown and whole-animal heterozygotes of Mmp1 increased additively sensitivity to paraquat-induced oxidative stress and shortened lifespan. Our data suggest that Drosophila Mmp1 is involved in the regulation of ISC proliferation for maintenance of gut homeostasis. -- Highlights: ► Mmp1 is expressed in the adult midgut. ► Mmp1 is involved in the regulation of ISC proliferation activity. ► Mmp1-related ISC proliferation is associated with EGFR signaling. ► Mmp1 in the gut is required for the intestinal homeostasis and longevity.

  14. Gene expression during Drosophila melanogaster egg development before and after reproductive diapause

    Directory of Open Access Journals (Sweden)

    Baker Dean A

    2009-05-01

    Full Text Available Abstract Background Despite the importance of egg development to the female life cycle in Drosophila, global patterns of gene expression have not been examined in detail, primarily due to the difficulty in isolating synchronised developmental stages in sufficient quantities for gene expression profiling. Entry into vitellogenesis is a key stage of oogenesis and by forcing females into reproductive diapause we are able to arrest oogenesis at the pre-vitellogenic stages. Releasing females from diapause allows collection of relatively synchronous developing egg populations and an investigation of some of the transcriptional dynamics apparent before and after reproductive diapause. Results Focusing on gender-biased transcription, we identified mechanisms of egg development suppressed during reproductive dormancy as well as other molecular changes unique to the diapausing female. A microarray based analysis generated a set of 3565 transcripts with at least 2-fold greater expression in females as compared to control males, 1392 such changes were biased during reproductive dormancy. In addition, we also detect 1922 up-regulated transcriptional changes after entry into vitellogenesis, which were classified into discrete blocks of co-expression. We discuss some of the regulatory aspects apparent after re-initiation of egg development, exploring the underlying functions, maternal contribution and evolutionary conservation of co-expression patterns involved in egg production. Conclusion Although much of the work we present is descriptive, fundamental aspects of egg development and gender-biased transcription can be derived from our time-series experiment. We believe that our dataset will facilitate further exploration of the developmental and evolutionary characteristics of oogenesis as well as the nature of reproductive arrest in Drosophila.

  15. Reduced glutathione biosynthesis in Drosophila melanogaster causes neuronal defects linked to copper deficiency.

    Science.gov (United States)

    Mercer, Stephen W; La Fontaine, Sharon; Warr, Coral G; Burke, Richard

    2016-05-01

    Glutathione (GSH) is a tripeptide often considered to be the master antioxidant in cells. GSH plays an integral role in cellular redox regulation and is also known to have a role in mammalian copper homeostasis. In vitro evidence suggests that GSH is involved in copper uptake, sequestration and efflux. This study was undertaken to further investigate the roles that GSH plays in neuronal copper homeostasis in vivo, using the model organism Drosophila melanogaster. RNA interference-mediated knockdown of the Glutamate-cysteine ligase catalytic subunit gene (Gclc) that encodes the rate-limiting enzyme in GSH biosynthesis was utilised to genetically deplete GSH levels. When Gclc was knocked down in all neurons, this caused lethality, which was partially rescued by copper supplementation and was exacerbated by additional knockdown of the copper uptake transporter Ctr1A, or over-expression of the copper efflux transporter ATP7. Furthermore, when Gclc was knocked down in a subset of neuropeptide-producing cells, this resulted in adult progeny with unexpanded wings, a phenotype previously associated with copper dyshomeostasis. In these cells, Gclc suppression caused a decrease in axon branching, a phenotype further enhanced by ATP7 over-expression. Therefore, we conclude that GSH may play an important role in regulating neuronal copper levels and that reduction in GSH may lead to functional copper deficiency in neurons in vivo. We provide genetic evidence that glutathione (GSH) levels influence Cu content or distribution in vivo, in Drosophila neurons. GSH could be required for binding Cu imported by Ctr1A and distributing it to chaperones, such as Mtn, CCS and Atox1. Alternatively, GSH could modify the copper-binding and transport activities of Atox1 and the ATP7 efflux protein via glutathionylation of copper-binding cysteines.

  16. Muscleblind, BSF and TBPH are mislocalized in the muscle sarcomere of a Drosophila myotonic dystrophy model

    Directory of Open Access Journals (Sweden)

    Beatriz Llamusi

    2013-01-01

    Myotonic dystrophy type 1 (DM1 is a genetic disease caused by the pathological expansion of a CTG trinucleotide repeat in the 3′ UTR of the DMPK gene. In the DMPK transcripts, the CUG expansions sequester RNA-binding proteins into nuclear foci, including transcription factors and alternative splicing regulators such as MBNL1. MBNL1 sequestration has been associated with key features of DM1. However, the basis behind a number of molecular and histological alterations in DM1 remain unclear. To help identify new pathogenic components of the disease, we carried out a genetic screen using a Drosophila model of DM1 that expresses 480 interrupted CTG repeats, i(CTG480, and a collection of 1215 transgenic RNA interference (RNAi fly lines. Of the 34 modifiers identified, two RNA-binding proteins, TBPH (homolog of human TAR DNA-binding protein 43 or TDP-43 and BSF (Bicoid stability factor; homolog of human LRPPRC, were of particular interest. These factors modified i(CTG480 phenotypes in the fly eye and wing, and TBPH silencing also suppressed CTG-induced defects in the flight muscles. In Drosophila flight muscle, TBPH, BSF and the fly ortholog of MBNL1, Muscleblind (Mbl, were detected in sarcomeric bands. Expression of i(CTG480 resulted in changes in the sarcomeric patterns of these proteins, which could be restored by coexpression with human MBNL1. Epistasis studies showed that Mbl silencing was sufficient to induce a subcellular redistribution of TBPH and BSF proteins in the muscle, which mimicked the effect of i(CTG480 expression. These results provide the first description of TBPH and BSF as targets of Mbl-mediated CTG toxicity, and they suggest an important role of these proteins in DM1 muscle pathology.

  17. Drosophila SLC5A11 Mediates Hunger by Regulating K(+) Channel Activity.

    Science.gov (United States)

    Park, Jin-Yong; Dus, Monica; Kim, Seonil; Abu, Farhan; Kanai, Makoto I; Rudy, Bernardo; Suh, Greg S B

    2016-08-01

    Hunger is a powerful drive that stimulates food intake. Yet, the mechanism that determines how the energy deficits that result in hunger are represented in the brain and promote feeding is not well understood. We previously described SLC5A11-a sodium/solute co-transporter-like-(or cupcake) in Drosophila melanogaster, which is required for the fly to select a nutritive sugar over a sweeter nonnutritive sugar after periods of food deprivation. SLC5A11 acts on approximately 12 pairs of ellipsoid body (EB) R4 neurons to trigger the selection of nutritive sugars, but the underlying mechanism is not understood. Here, we report that the excitability of SLC5A11-expressing EB R4 neurons increases dramatically during starvation and that this increase is abolished in the SLC5A11 mutation. Artificial activation of SLC5A11-expresssing neurons is sufficient to promote feeding and hunger-driven behaviors; silencing these neurons has the opposite effect. Notably, SLC5A11 transcript levels in the brain increase significantly when flies are starved and decrease shortly after starved flies are refed. Furthermore, expression of SLC5A11 is sufficient for promoting hunger-driven behaviors and enhancing the excitability of SLC5A11-expressing neurons. SLC5A11 inhibits the function of the Drosophila KCNQ potassium channel in a heterologous expression system. Accordingly, a knockdown of dKCNQ expression in SLC5A11-expressing neurons produces hunger-driven behaviors even in fed flies, mimicking the overexpression of SLC5A11. We propose that starvation increases SLC5A11 expression, which enhances the excitability of SLC5A11-expressing neurons by suppressing dKCNQ channels, thereby conferring the hunger state. PMID:27397890

  18. Drosophila wing modularity revisited through a quantitative genetic approach.

    Science.gov (United States)

    Muñoz-Muñoz, Francesc; Carreira, Valeria Paula; Martínez-Abadías, Neus; Ortiz, Victoria; González-José, Rolando; Soto, Ignacio M

    2016-07-01

    To predict the response of complex morphological structures to selection it is necessary to know how the covariation among its different parts is organized. Two key features of covariation are modularity and integration. The Drosophila wing is currently considered a fully integrated structure. Here, we study the patterns of integration of the Drosophila wing and test the hypothesis of the wing being divided into two modules along the proximo-distal axis, as suggested by developmental, biomechanical, and evolutionary evidence. To achieve these goals we perform a multilevel analysis of covariation combining the techniques of geometric morphometrics and quantitative genetics. Our results indicate that the Drosophila wing is indeed organized into two main modules, the wing base and the wing blade. The patterns of integration and modularity were highly concordant at the phenotypic, genetic, environmental, and developmental levels. Besides, we found that modularity at the developmental level was considerably higher than modularity at other levels, suggesting that in the Drosophila wing direct developmental interactions are major contributors to total phenotypic shape variation. We propose that the precise time at which covariance-generating developmental processes occur and/or the magnitude of variation that they produce favor proximo-distal, rather than anterior-posterior, modularity in the Drosophila wing. PMID:27272402

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

    Science.gov (United States)

    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. PMID:23378635

  20. big bang gene modulates gut immune tolerance in Drosophila

    Science.gov (United States)

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

    2013-01-01

    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. PMID:23378635

  1. Intestinal stem cells in the adult Drosophila midgut

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Huaqi, E-mail: Huaqi.Jiang@UTSouthwestern.edu [Department of Developmental Biology, UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX, 75235 (United States); Edgar, Bruce A., E-mail: b.edgar@dkfz.de [ZMBH-DKFZ Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg (Germany); Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109 (United States)

    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.

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

    Science.gov (United States)

    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

    2016-06-28

    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

  3. Research progress on Drosophila visual cognition in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Visual cognition,as one of the fundamental aspects of cognitive neuroscience,is generally associated with high-order brain functions in animals and human.Drosophila,as a model organism,shares certain features of visual cognition in common with mammals at the genetic,molecular,cellular,and even higher behavioral levels.From learning and memory to decision making,Drosophila covers a broad spectrum of higher cognitive behaviors beyond what we had expected.Armed with powerful tools of genetic manipulation in Drosophila,an increasing number of studies have been conducted in order to elucidate the neural circuit mechanisms underlying these cognitive behaviors from a genes-brain-behavior perspective.The goal of this review is to integrate the most important studies on visual cognition in Drosophila carried out in mainland China during the last decade into a body of knowledge encompassing both the basic neural operations and circuitry of higher brain function in Drosophila.Here,we consider a series of the higher cognitive behaviors beyond learning and memory,such as visual pattern recognition,feature and context generalization,different feature memory traces,salience-based decision,attention-like behavior,and cross-modal leaning and memory.We discuss the possible general gain-gating mechanism implementing by dopamine-mushroom body circuit in fly’s visual cognition.We hope that our brief review on this aspect will inspire further study on visual cognition in flies,or even beyond.

  4. Biological radiation effects of Radon in Drosophila

    International Nuclear Information System (INIS)

    In order to contribute to the knowledge on the effects of radon and its decay products, the aim of this investigation is to study the biological effects of radon using Drosophila melanogaster throught the somatic mutation and recombination test (SMART) and the analysis of some adaptative factors exposing larvaes to controlled radon atmosphers, considering that this insect could be used as biological monitor. Using the somatic mutation test a mutagenic effect was observed proportional to radon concentration, into an interval of 1 ± 0.3 to 111 ± 7.4 KBq/m3 equivalent to doses under 0.0106 Gy. The correlation analysis gives a linear (r=0.80) relationship with a positive slope of 0.2217. The same happens when gamma rays are used in the interval of 1 to 20 Gy, given a linear dose-dependent effect (r=0.878) is obtained; nevetheless the slop is smaller (m=0.003) than for radon. Analysing the results of adaptative factors of the nine exposed generations, it was found that probably radon exposition induced dominant lethals during gametogenesis or/and a selection of the more component gamets of the treated individuals in larval state. It was reflected in the significant decrease on fecundity of the generation exposed. Nevertheless the laying eggs had an increase in egg-to-adult viability and the develop velocity was higher than in control for 3 KBq/m3, this suggest that radon concentrations used were able to induce repair mechanisms. These data agree with the Hormesis hypothesis that says: low doses have positive effects on health. It was not possible to obtain a dose-effect relationship except with the develop velocity where it was found a dose-effect inverse proportion. In conclusion, Drosophila melanogaster could be a good system to obtain in vivo damaged induction concentration dependent of radon and its decay products, as well as to study the effects in an exposed population by the analysis of adaptative factors. (Author)

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

    Science.gov (United States)

    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. PMID:26523848

  6. Quantifying host potentials: indexing postharvest fresh fruits for spotted wing Drosophila, Drosophila suzukii.

    Directory of Open Access Journals (Sweden)

    David E Bellamy

    Full Text Available Novel methodology is presented for indexing the relative potential of hosts to function as resources. A Host Potential Index (HPI was developed as a practical framework to express relative host potential based on combining results from one or more independent studies, such as those examining host selection, utilization, and physiological development of the organism resourcing the host. Several aspects of the HPI are addressed including: 1 model derivation; 2 influence of experimental design on establishing host rankings for a study type (no choice, two-choice, and multiple-choice; and, 3 variable selection and weighting associated with combining multiple studies. To demonstrate application of the HPI, results from the interactions of spotted wing drosophila (SWD, Drosophila suzukii Matsumura (Diptera: Drosophilidae, with seven "reported" hosts (blackberries, blueberries, sweet cherries, table grapes, peaches, raspberries, and strawberries in a postharvest scenario were analyzed. Four aspects of SWD-host interaction were examined: attraction to host volatiles; population-level oviposition performance; individual-level oviposition performance; and key developmental factors. Application of HPI methodology indicated that raspberries ( (meanHPIvaried  = 301.9±8.39; rank 1 of 7 have the greatest potential to serve as a postharvest host for SWD relative to the other fruit hosts, with grapes ( (meanHPIvaried  = 232.4±3.21; rank 7 of 7 having the least potential.

  7. Patterns of mutation and selection at synonymous sites in Drosophila

    DEFF Research Database (Denmark)

    Singh, Nadia D; Bauer DuMont, Vanessa L; Hubisz, Melissa J;

    2007-01-01

    That natural selection affects molecular evolution at synonymous sites in protein-coding sequences is well established and is thought to predominantly reflect selection for translational efficiency/accuracy mediated through codon bias. However, a recently developed maximum likelihood framework...... be subject to a variety of selective pressures beyond weak selection for increased frequencies of the codons currently defined as "preferred" in D. melanogaster. To further explore patterns of synonymous site evolution in Drosophila in a lineage-specific manner, we expanded the application of the maximum......, when applied to 18 coding sequences in 3 species of Drosophila, confirmed an earlier report that the Notch gene in Drosophila melanogaster was evolving under selection in favor of those codons defined as unpreferred in this species. This finding opened the possibility that synonymous sites may...

  8. On the origin of new genes in Drosophila

    DEFF Research Database (Denmark)

    Zhou, Qi; Zhang, Guojie; Zhang, Yue;

    2008-01-01

    Several mechanisms have been proposed to account for the origination of new genes. Despite extensive case studies, the general principles governing this fundamental process are still unclear at the whole-genome level. Here, we unveil genome-wide patterns for the mutational mechanisms leading to new...... genes and their subsequent lineage-specific evolution at different time nodes in the Drosophila melanogaster species subgroup. We find that (1) tandem gene duplication has generated approximately 80% of the nascent duplicates that are limited to single species (D. melanogaster or Drosophila yakuba); (2...... and reveal that 44.4% of them show copy number polymorphisms within a population. In conclusion, we provide a panoramic picture for the origin of new genes in Drosophila species....

  9. Intestinal stem cell response to injury: lessons from Drosophila.

    Science.gov (United States)

    Jiang, Huaqi; Tian, Aiguo; Jiang, Jin

    2016-09-01

    Many adult tissues and organs are maintained by resident stem cells that are activated in response to injury but the mechanisms that regulate stem cell activity during regeneration are still poorly understood. An emerging system to study such problem is the Drosophila adult midgut. Recent studies have identified both intrinsic factors and extrinsic niche signals that control the proliferation, self-renewal, and lineage differentiation of Drosophila adult intestinal stem cells (ISCs). These findings set up the stage to interrogate how niche signals are regulated and how they are integrated with cell-intrinsic factors to control ISC activity during normal homeostasis and regeneration. Here we review the current understanding of the mechanisms that control ISC self-renewal, proliferation, and lineage differentiation in Drosophila adult midgut with a focus on the niche signaling network that governs ISC activity in response to injury. PMID:27137186

  10. Insights on TRP Channels from In Vivo Studies in Drosophila

    Science.gov (United States)

    Minke, Baruch; Parnas, Moshe

    2007-01-01

    Transient receptor potential (TRP) channels mediate responses in a large variety of signaling mechanisms. Most studies on mammalian TRP channels rely on heterologous expression, but their relevance to in vivo tissues is not entirely clear. In contrast, Drosophila TRP and TRP-like (TRPL) channels allow direct analyses of in vivo function. In Drosophila photoreceptors, activation of TRP and TRPL is mediated via the phosphoinositide cascade, with both Ca2+ and diacylglycerol (DAG) essential for generating the light response. In tissue culture cells, TRPL channels are constitutively active, and lipid second messengers greatly facilitate this activity. Inhibition of phospholipase C (PLC) completely blocks lipid activation of TRPL, suggesting that lipid activation is mediated via PLC. In vivo studies in mutant Drosophila also reveal an acute requirement for lipid-producing enzyme, which may regulate PLC activity. Thus, PLC and its downstream second messengers, Ca2+ and DAG, constitute critical mediators of TRP/TRPL gating in vivo. PMID:16460287

  11. Identification of common excitatory motoneurons in Drosophila melanogaster larvae.

    Science.gov (United States)

    Takizawa, Eiji; Komatsu, Akira; Tsujimura, Hidenobu

    2007-05-01

    In insects, four types of motoneurons have long been known, including fast motoneurons, slow motoneurons, common inhibitory motoneurons, and DUM neurons. They innervate the same muscle and control its contraction together. Recent studies in Drosophila have suggested the existence of another type of motoneuron, the common excitatory motoneuron. Here, we found that shakB-GAL4 produced by labels this type of motoneuron in Drosophila larvae. We found that Drosophila larvae have two common excitatory motoneurons in each abdominal segment, RP2 for dorsal muscles and MNSNb/d-Is for ventral muscles. They innervate most of the internal longitudinal or oblique muscles on the dorsal or ventral body wall with type-Is terminals and use glutamate as a transmitter. Electrophysiological recording indicated that stimulation of the RP2 axon evoked excitatory junctional potential in a dorsal muscle. PMID:17867850

  12. Chemical genetics and drug screening in Drosophila cancer models

    Institute of Scientific and Technical Information of China (English)

    Mara Gladstone; Tin Tin Su

    2011-01-01

    Drug candidates often fail in preclinical and clinical testing because of reasons of efficacy and/or safety.It would be time- and cost-efficient to have screening models that reduce the rate of such false positive candidates that appear promising at first but fail later.In this regard,it would be particularly useful to have a rapid and inexpensive whole animal model that can pre-select hits from high-throughput screens but before testing in costly rodent assays.Drosophila melanogaster has emerged as a potential whole animal model for drug screening.Of particular interest have been drugs that must act in the context of multi-cellularity such as those for neurological disorders and cancer.A recent review provides a comprehensive summary of drug screening in Drosophila,but with an emphasis on neurodegenerative disorders.Here,we review Drosophila screens in the literature aimed at cancer therapeutics.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Third Chromosome Balancer Inversions Disrupt Protein-Coding Genes and Influence Distal Recombination Events in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Danny E. Miller

    2016-07-01

    Full Text Available Balancer chromosomes are multiply inverted chromosomes that suppress meiotic crossing over and prevent the recovery of crossover products. Balancers are commonly used in Drosophila melanogaster to maintain deleterious alleles and in stock construction. They exist for all three major chromosomes, yet the molecular location of the breakpoints and the exact nature of many of the mutations carried by the second and third chromosome balancers has not been available. Here, we precisely locate eight of 10 of the breakpoints on the third chromosome balancer TM3, six of eight on TM6, and nine of 11 breakpoints on TM6B. We find that one of the inversion breakpoints on TM3 bisects the highly conserved tumor suppressor gene p53—a finding that may have important consequences for a wide range of studies in Drosophila. We also identify evidence of single and double crossovers between several TM3 and TM6B balancers and their normal-sequence homologs that have created genetic diversity among these chromosomes. Overall, this work demonstrates the practical importance of precisely identifying the position of inversion breakpoints of balancer chromosomes and characterizing the mutant alleles carried by them.

  15. Caffeine Taste Signaling in Drosophila Larvae.

    Science.gov (United States)

    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

  16. Structure of full-length Drosophila cryptochrome

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  17. Tools for neuroanatomy and neurogenetics in Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Thermal stress depletes energy reserves in Drosophila.

    Science.gov (United States)

    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

  19. Host plant adaptation in Drosophila mettleri populations.

    Science.gov (United States)

    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

  20. Host plant adaptation in Drosophila mettleri populations.

    Directory of Open Access Journals (Sweden)

    Sergio Castrezana

    Full Text Available 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.

  1. Transgenerational memory effect of ageing in Drosophila.

    Science.gov (United States)

    Burns, James G; Mery, Frederic

    2010-04-01

    Children born to older parents tend to have lower intelligence and are at higher risk for disorders such as schizophrenia and autism. Such observations of ageing damage being passed on from parents to offspring are not often considered within the evolutionary theory of ageing. Here, we show the 25% memory impairment in Drosophila melanogaster offspring solely dependent on the age of the parents and also passed on to the F2 generation. Furthermore, this parental age effect was not attributed to a generalized reduction in condition of the offspring but was specific to short-term memory. We also provide evidence implicating oxidative stress as a causal factor by showing that lines selected for resistance to oxidative stress did not display a memory impairment in offspring of old parents. The identification of the parental age-related memory impairment in a model system should stimulate integration between mechanistic studies of age-related mortality risk and functional studies of parental age effects on the fitness of future generations. PMID:20149023

  2. Effects of Spaceflight on Drosophila Neural Development

    Science.gov (United States)

    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.

  3. Mechanosensory interactions drive collective behaviour in Drosophila.

    Science.gov (United States)

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

    2015-03-12

    Collective behaviour enhances environmental sensing and decision-making in groups of animals. Experimental and theoretical investigations of schooling fish, flocking birds and human crowds have demonstrated that simple interactions between individuals can explain emergent group dynamics. These findings indicate 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 NOMPC. 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

  4. Functional neuroanatomy of Drosophila olfactory memory formation.

    Science.gov (United States)

    Guven-Ozkan, Tugba; Davis, Ronald L

    2014-10-01

    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

  5. A Model of Drosophila Larva Chemotaxis.

    Directory of Open Access Journals (Sweden)

    Alex Davies

    2015-11-01

    Full Text Available 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.

  6. Tracking individual nanodiamonds in Drosophila melanogaster embryos

    CERN Document Server

    Simpson, David A; Kowarsky, Mark; Zeeshan, Nida F; Barson, Michael S J; Hall, Liam; Yan, Yan; Kaufmann, Stefan; Johnson, Brett C; Ohshima, Takeshi; Caruso, Frank; Scholten, Robert; Saint, Robert B; Murray, Michael J; Hollenberg, Lloyd C L

    2013-01-01

    Tracking the dynamics of fluorescent nanoparticles during embryonic development allows insights into the physical state of the embryo and, potentially, molecular processes governing developmental mechanisms. In this work, we investigate the motion of individual fluorescent nanodiamonds micro-injected into Drosophila melanogaster embryos prior to cellularisation. Fluorescence correlation spectroscopy and wide-field imaging techniques are applied to individual fluorescent nanodiamonds in blastoderm cells during stage 5 of development to a depth of ~40 \\mu m. The majority of nanodiamonds in the blastoderm cells during cellularisation exhibit free diffusion with an average diffusion coefficient of (6 $\\pm$ 3) x 10$^{-3}$ \\mu m$^2$/s, (mean $\\pm$ SD). Driven motion in the blastoderm cells was also observed with an average velocity of 0.13 $\\pm$ 0.10 \\mu m/s (mean $\\pm$ SD) \\mu m/s and an average applied force of 0.07 $\\pm$ 0.05 pN (mean $\\pm$ SD). Nanodiamonds in the periplasm between the nuclei and yolk were also...

  7. Thermal stress depletes energy reserves in Drosophila

    Science.gov (United States)

    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

  8. How food controls aggression in Drosophila.

    Directory of Open Access Journals (Sweden)

    Rod S Lim

    Full Text Available How animals use sensory information to weigh the risks vs. benefits of behavioral decisions remains poorly understood. Inter-male aggression is triggered when animals perceive both the presence of an appetitive resource, such as food or females, and of competing conspecific males. How such signals are detected and integrated to control the decision to fight is not clear. For instance, it is unclear whether food increases aggression directly, or as a secondary consequence of increased social interactions caused by attraction to food. Here we use the vinegar fly, Drosophila melanogaster, to investigate the manner by which food influences aggression. We show that food promotes aggression in flies, and that it does so independently of any effect on frequency of contact between males, increase in locomotor activity or general enhancement of social interactions. Importantly, the level of aggression depends on the absolute amount of food, rather than on its surface area or concentration. When food resources exceed a certain level, aggression is diminished, suggestive of reduced competition. Finally, we show that detection of sugar via Gr5a+ gustatory receptor neurons (GRNs is necessary for food-promoted aggression. These data demonstrate that food exerts a specific effect to promote aggression in male flies, and that this effect is mediated, at least in part, by sweet-sensing GRNs.

  9. Ferritin Assembly in Enterocytes of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Abraham Rosas-Arellano

    2016-02-01

    Full Text Available 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.

  10. Reinforcement of gametic isolation in Drosophila.

    Directory of Open Access Journals (Sweden)

    Daniel R Matute

    2010-03-01

    Full Text Available Reinforcement, a process by which natural selection increases reproductive isolation between populations, has been suggested to be an important force in the formation of new species. However, all existing cases of reinforcement involve an increase in mate discrimination between species. Here, I report the first case of reinforcement of postmating prezygotic isolation (i.e., barriers that act after mating but before fertilization in animals. On the slopes of the African island of São Tomé, Drosophila yakuba and its endemic sister species D. santomea hybridize within a well-demarcated hybrid zone. I find that D. yakuba females from within this zone, but not from outside it, show an increase in gametic isolation from males of D. santomea, an apparent result of natural selection acting to reduce maladaptive hybridization between species. To determine whether such a barrier could evolve under laboratory conditions, I exposed D. yakuba lines derived from allopatric populations to experimental sympatry with D. santomea, and found that both behavioral and gametic isolation become stronger after only four generations. Reinforcement thus appears to be the best explanation for the heightened gametic isolation seen in sympatry. This appears to be the first example in animals in which natural selection has promoted the evolution of stronger interspecific genetic barriers that act after mating but before fertilization. This suggests that many other genetic barriers between species have been increased by natural selection but have been overlooked because they are difficult to study.

  11. Collective synchronization of divisions in Drosophila development

    Science.gov (United States)

    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. Insulin signaling mediates sexual attractiveness in Drosophila.

    Directory of Open Access Journals (Sweden)

    Tsung-Han Kuo

    Full Text Available Sexually attractive characteristics are often thought to reflect an individual's condition or reproductive potential, but the underlying molecular mechanisms through which they do so are generally unknown. Insulin/insulin-like growth factor signaling (IIS is known to modulate aging, reproduction, and stress resistance in several species and to contribute to variability of these traits in natural populations. Here we show that IIS determines sexual attractiveness in Drosophila through transcriptional regulation of genes involved in the production of cuticular hydrocarbons (CHC, many of which function as pheromones. Using traditional gas chromatography/mass spectrometry (GC/MS together with newly introduced laser desorption/ionization orthogonal time-of-flight mass spectrometry (LDI-MS we establish that CHC profiles are significantly affected by genetic manipulations that target IIS. Manipulations that reduce IIS also reduce attractiveness, while females with increased IIS are significantly more attractive than wild-type animals. IIS effects on attractiveness are mediated by changes in CHC profiles. Insulin signaling influences CHC through pathways that are likely independent of dFOXO and that may involve the nutrient-sensing Target of Rapamycin (TOR pathway. These results suggest that the activity of conserved molecular regulators of longevity and reproductive output may manifest in different species as external characteristics that are perceived as honest indicators of fitness potential.

  13. Soft substrates suppress droplet splashing

    CERN Document Server

    Howland, Christopher J; Style, Robert W; Castrejón-Pita, A A

    2015-01-01

    Droplets splash when they impact dry, flat substrates above a critical velocity that depends on parameters such as droplet size, viscosity and air pressure. We show that substrate stiffness also impacts the splashing threshold by imaging ethanol drops impacting silicone gels of different stiffnesses. Splashing is significantly suppressed: droplets on the softest substrates need over 70% more kinetic energy to splash than they do on rigid substrates. We show that splash suppression is likely to be due to energy losses caused by deformations of soft substrates during the first few microseconds of impact. We find that solids with Youngs modulus $\\lesssim O(10^5)$Pa suppress splashing, in agreement with simple scaling arguments. Thus materials like soft gels and elastomers can be used as simple coatings for effective splash prevention.

  14. Aging and repeated thought suppression success.

    Directory of Open Access Journals (Sweden)

    Ann E Lambert

    Full Text Available Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differences in reactions to thought suppression attempts across four thought suppression sequences in 40 older and 42 younger adults. As expected, age differences were more prevalent during suppression than during free monitoring periods, with younger adults indicating longer, more frequent thought recurrences and greater suppression difficulty. Further, younger adults' thought suppression outcomes changed over time, while trajectories for older adults' were relatively stable. Results are discussed in terms of older adults' reduced thought recurrence, which was potentially afforded by age-related changes in reactive control and distractibility.

  15. Aging and repeated thought suppression success.

    Science.gov (United States)

    Lambert, Ann E; Smyth, Frederick L; Beadel, Jessica R; Teachman, Bethany A

    2013-01-01

    Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differences in reactions to thought suppression attempts across four thought suppression sequences in 40 older and 42 younger adults. As expected, age differences were more prevalent during suppression than during free monitoring periods, with younger adults indicating longer, more frequent thought recurrences and greater suppression difficulty. Further, younger adults' thought suppression outcomes changed over time, while trajectories for older adults' were relatively stable. Results are discussed in terms of older adults' reduced thought recurrence, which was potentially afforded by age-related changes in reactive control and distractibility. PMID:23776442

  16. The making of a fusion branch in the Drosophila trachea.

    Science.gov (United States)

    Gervais, Louis; Lebreton, Gaelle; Casanova, Jordi

    2012-02-15

    Connection of epithelial tubes to generate a common network is a key step in the formation of tubular organs such as the tracheal respiratory and the vascular systems. However, it is not clear how these connecting tubes arise. Here we address this issue by studying the dorsal fusion branches in the Drosophila trachea, taking into account the morphology and contribution of each cell type on the basis of their individual labeling. Our results explain how a fusion branch forms and also illustrate the different nature of the two seamless tubes in the Drosophila trachea, generated by fusion and terminal cells respectively. PMID:22178247

  17. Getting started : an overview on raising and handling Drosophila.

    Science.gov (United States)

    Stocker, Hugo; Gallant, Peter

    2008-01-01

    Drosophila melanogaster has long been a prime model organism for developmental biologists. During their work, they have established a large collection of techniques and reagents. This in turn has made fruit flies an attractive system for many other biomedical researchers who have otherwise no background in fly biology. This review intends to help Drosophila neophytes in setting up a fly lab. It briefly introduces the biological properties of fruit flies, describes the minimal equipment required for working with flies, and offers some basic advice for maintaining fly lines and setting up and analyzing experiments. PMID:18641939

  18. Modeling dietary influences on offspring metabolic programming in Drosophila melanogaster.

    Science.gov (United States)

    Brookheart, Rita T; Duncan, Jennifer G

    2016-09-01

    The influence of nutrition on offspring metabolism has become a hot topic in recent years owing to the growing prevalence of maternal and childhood obesity. Studies in mammals have identified several factors correlating with parental and early offspring dietary influences on progeny health; however, the molecular mechanisms that underlie these factors remain undiscovered. Mammalian metabolic tissues and pathways are heavily conserved in Drosophila melanogaster, making the fly an invaluable genetic model organism for studying metabolism. In this review, we discuss the metabolic similarities between mammals and Drosophila and present evidence supporting its use as an emerging model of metabolic programming. PMID:27450801

  19. Genetic regulation of programmed cell death in Drosophila

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided valuable information toward our understanding of genetic regulation of death. Different signals trigger the novel death regulators rpr, hid, and grim, that utilize the evolutionarily conserved iap and ark genes to modulate caspase function. Subsequent removal of dying cells also appears to be accomplished by conserved mechanisms. The similarity between Drosophila and human in cell death signaling pathways illustrate the promise of fruit flies as a model system to elucidate the mechanisms underlying regulation of programmed cell death.

  20. Teaching to suppress Polglish processes

    OpenAIRE

    Dziubalska-Kołaczyk, Katarzyna; Balas, Anna; Schwartz, Geoffrey; Rojczyk, Arkadiusz; Wrembel, Magdalena

    2015-01-01

    Advanced second language (henceforth L2) learners in a formal setting can suppress many first language (henceforth L1) processes in L2 pronunciation when provided with sufficient exposure to L2 and meta competence (see Sect. 4 for a definition of this term). This paper shows how imitation in L2 teaching can be enhanced on the basis of current phonetic research and how complex allophonic processes such as nasal vocalization and glottal stop insertion can be suppressed using “repair”—a method o...

  1. Aging and Repeated Thought Suppression Success

    OpenAIRE

    Ann E Lambert; Smyth, Frederick L.; Jessica R Beadel; Teachman, Bethany A.

    2013-01-01

    Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differe...

  2. EGFR signaling promotes self-renewal through the establishment of cell polarity in Drosophila follicle stem cells.

    Science.gov (United States)

    Castanieto, Angela; Johnston, Michael J; Nystul, Todd G

    2014-01-01

    Epithelial stem cells divide asymmetrically, such that one daughter replenishes the stem cell pool and the other differentiates. We found that, in the epithelial follicle stem cell (FSC) lineage of the Drosophila ovary, epidermal growth factor receptor (EGFR) signaling functions specifically in the FSCs to promote the unique partially polarized state of the FSC, establish apical-basal polarity throughout the lineage, and promote FSC maintenance in the niche. In addition, we identified a novel connection between EGFR signaling and the cell-polarity regulator liver kinase B1 (LKB1), which indicates that EGFR signals through both the Ras-Raf-MEK-Erk pathway and through the LKB1-AMPK pathway to suppress apical identity. The development of apical-basal polarity is the earliest visible difference between FSCs and their daughters, and our findings demonstrate that the EGFR-mediated regulation of apical-basal polarity is essential for the segregation of stem cell and daughter cell fates. PMID:25437306

  3. Conditioned suppression, punishment, and aversion

    Science.gov (United States)

    Orme-Johnson, D. W.; Yarczower, M.

    1974-01-01

    The aversive action of visual stimuli was studied in two groups of pigeons which received response-contingent or noncontingent electric shocks in cages with translucent response keys. Presentation of grain for 3 sec, contingent on key pecking, was the visual stimulus associated with conditioned punishment or suppression. The responses of the pigeons in three different experiments are compared.

  4. A correlation of reactive oxygen species accumulation by depletion of superoxide dismutases with age-dependent impairment in the nervous system and muscles of Drosophila adults.

    Science.gov (United States)

    Oka, Saori; Hirai, Jun; Yasukawa, Takashi; Nakahara, Yasuyuki; Inoue, Yoshihiro H

    2015-08-01

    The theory that accumulation of reactive oxygen species (ROS) in internal organs is a major promoter of aging has been considered negatively. However, it is still controversial whether overexpression of superoxide dismutases (SODs), which remove ROS, extends the lifespan in Drosophila adults. We examined whether ROS accumulation by depletion of Cu/Zn-SOD (SOD1) or Mn-SOD (SOD2) influenced age-related impairment of the nervous system and muscles in Drosophila. We confirmed the efficient depletion of Sod1 and Sod2 through RNAi and ROS accumulation by monitoring of ROS-inducible gene expression. Both RNAi flies displayed accelerated impairment of locomotor activity with age and shortened lifespan. Similarly, adults with nervous system-specific depletion of Sod1 or Sod2 also showed reduced lifespan. We then found an accelerated loss of dopaminergic neurons in the flies with suppressed SOD expression. A half-dose reduction of three pro-apoptotic genes resulted in a significant suppression of the neuronal loss, suggesting that apoptosis was involved in the neuronal loss caused by SOD silencing. In addition, depletion of Sod1 or Sod2 in musculature is also associated with enhancement of age-related locomotion impairment. In indirect flight muscles from SOD-depleted adults, abnormal protein aggregates containing poly-ubiquitin accumulated at an early adult stage and continued to increase as the flies aged. Most of these protein aggregates were observed between myofibril layers. Moreover, immuno-electron microscopy indicated that the aggregates were predominantly localized in damaged mitochondria. These findings suggest that muscular and neuronal ROS accumulation may have a significant effect on age-dependent impairment of the Drosophila adults.

  5. Modeling peripheral olfactory coding in Drosophila larvae.

    Directory of Open Access Journals (Sweden)

    Derek J Hoare

    Full Text Available The Drosophila larva possesses just 21 unique and identifiable pairs of olfactory sensory neurons (OSNs, enabling investigation of the contribution of individual OSN classes to the peripheral olfactory code. We combined electrophysiological and computational modeling to explore the nature of the peripheral olfactory code in situ. We recorded firing responses of 19/21 OSNs to a panel of 19 odors. This was achieved by creating larvae expressing just one functioning class of odorant receptor, and hence OSN. Odor response profiles of each OSN class were highly specific and unique. However many OSN-odor pairs yielded variable responses, some of which were statistically indistinguishable from background activity. We used these electrophysiological data, incorporating both responses and spontaneous firing activity, to develop a bayesian decoding model of olfactory processing. The model was able to accurately predict odor identity from raw OSN responses; prediction accuracy ranged from 12%-77% (mean for all odors 45.2% but was always significantly above chance (5.6%. However, there was no correlation between prediction accuracy for a given odor and the strength of responses of wild-type larvae to the same odor in a behavioral assay. We also used the model to predict the ability of the code to discriminate between pairs of odors. Some of these predictions were supported in a behavioral discrimination (masking assay but others were not. We conclude that our model of the peripheral code represents basic features of odor detection and discrimination, yielding insights into the information available to higher processing structures in the brain.

  6. A product of the bicistronic Drosophila melanogaster gene CG31241, which also encodes a trimethylguanosine synthase, plays a role in telomere protection.

    Science.gov (United States)

    Komonyi, Orban; Schauer, Tamas; Papai, Gabor; Deak, Peter; Boros, Imre M

    2009-03-15

    Although telomere formation occurs through a different mechanism in Drosophila compared with other organisms, telomere associations result from mutations in homologous genes, indicating the involvement of similar pathways in chromosome end protection. We report here that mutations of the Drosophila melanogaster gene CG31241 lead to high frequency chromosome end fusions. CG31241 is a bicistronic gene that encodes trimethylguanosine synthase (TGS1), which forms the m3G caps of noncoding small RNAs, and a novel protein, DTL. We show that although TGS1 has no role in telomere protection, DTL is localized at specific sites, including the ends of polytene chromosomes, and its loss results in telomere associations. Mutations of ATM- and Rad3-related (ATR) kinase suppress telomere fusions in the absence of DTL. Thus, genetic interactions place DTL in an ATR-related pathway in telomere protection. In contrast to ATR kinase, mutations of ATM (ataxia telangiectasia mutated) kinase, which acts in a partially overlapping pathway of telomere protection, do not suppress formation of telomere associations in the absence of DTL. Thus, uncovering the role of DTL will help to dissect the evolutionary conserved pathway(s) controlling ATM-ATR-related telomere protection.

  7. Genetic Analysis of the Hairy Locus in DROSOPHILA MELANOGASTER

    OpenAIRE

    Ingham, P W; Pinchin, S M; Howard, K.R.; Ish-Horowicz, D.

    1985-01-01

    Mutations of the hairy locus in Drosophila may affect both adult chaeta differentiation and embryonic segmentation. In an effort to understand this phenotypic complexity, we have analyzed 30 mutant alleles of the locus. We find that the alleles fall into four groups according to their complementation properties, suggesting a structurally complex locus in which two distinct functions share a common coding region.

  8. Interaction between the Drosophila heterochromatin proteins SUUR and HP1

    NARCIS (Netherlands)

    A.V. Pindyurin (Alexey); L.V. Boldyreva (Lidiya); V.V. Shloma (Victor); T.D. Kolesnikova (Tatiana); G.V. Pokholkova (Galina); E.N. Andreyeva (Evgeniya); E. Kozhevnikova (Elena); I.G. Ivanoschuk (Igor); E.A. Zarutskaya (Ekaterina); S.A. Demakov (Sergey); A.A. Gorchakov (Andrey); E.S. Belyaeva (Elena); I.F. Zhimulev (Igor)

    2008-01-01

    textabstractSUUR (Suppressor of Under-Replication) protein is responsible for late replication and, as a consequence, for DNA underreplication of intercalary and pericentric heterochromatin in Drosophila melanogaster polytene chromosomes. However, the mechanism by which SUUR slows down the replicati

  9. Plexins function in epithelial repair in both Drosophila and zebrafish

    Science.gov (United States)

    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

  10. Bazooka mediates secondary axon morphology in Drosophila brain lineages

    Directory of Open Access Journals (Sweden)

    Hartenstein Volker

    2011-04-01

    Full Text Available Abstract In the Drosophila brain, neural lineages project bundled axon tracts into a central neuropile. Each lineage exhibits a stereotypical branching pattern and trajectory, which distinguish it from other lineages. In this study, we used a multilineage approach to explore the neural function of the Par-complex member Par3/Bazooka in vivo. Drosophila bazooka is expressed in post-mitotic neurons of the larval brain and localizes within neurons in a lineage-dependent manner. The fact that multiple GAL4 drivers have been mapped to several lineages of the Drosophila brain enables investigation of the role of Bazooka from larval to adult stages Bazooka loss-of-function (LOF clones had abnormal morphologies, including aberrant pathway choice of ventral projection neurons in the BAla1 lineage, ectopic branching in the DALv2 and BAmv1 lineages, and excess BLD5 lineage axon projections in the optic medulla. Exogenous expression of Bazooka protein in BAla1 neurons rescued defective guidance, supporting an intrinsic requirement for Bazooka in the post-mitotic neuron. Elimination of the Par-complex member Par6 recapitulated Bazooka phenotypes in some but not all lineages, suggesting that the Par complex functions in a lineage-dependent manner, and that Bazooka may act independently in some lineages. Importantly, this study highlights the potential of using a multilineage approach when studying gene function during neural development in Drosophila.

  11. Bazooka mediates secondary axon morphology in Drosophila brain lineages.

    Science.gov (United States)

    Spindler, Shana R; Hartenstein, Volker

    2011-01-01

    In the Drosophila brain, neural lineages project bundled axon tracts into a central neuropile. Each lineage exhibits a stereotypical branching pattern and trajectory, which distinguish it from other lineages. In this study, we used a multilineage approach to explore the neural function of the Par-complex member Par3/Bazooka in vivo. Drosophila bazooka is expressed in post-mitotic neurons of the larval brain and localizes within neurons in a lineage-dependent manner. The fact that multiple GAL4 drivers have been mapped to several lineages of the Drosophila brain enables investigation of the role of Bazooka from larval to adult stages Bazooka loss-of-function (LOF) clones had abnormal morphologies, including aberrant pathway choice of ventral projection neurons in the BAla1 lineage, ectopic branching in the DALv2 and BAmv1 lineages, and excess BLD5 lineage axon projections in the optic medulla. Exogenous expression of Bazooka protein in BAla1 neurons rescued defective guidance, supporting an intrinsic requirement for Bazooka in the post-mitotic neuron. Elimination of the Par-complex member Par6 recapitulated Bazooka phenotypes in some but not all lineages, suggesting that the Par complex functions in a lineage-dependent manner, and that Bazooka may act independently in some lineages. Importantly, this study highlights the potential of using a multilineage approach when studying gene function during neural development in Drosophila. PMID:21524279

  12. Fly foie gras: modeling fatty liver in Drosophila.

    Science.gov (United States)

    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.

  13. Dynamics of genetic rescue in inbred Drosophila melanogaster populations

    NARCIS (Netherlands)

    Bijlsma, R.; Westerhof, M. D. D.; Roekx, L. P.; Pen, I.

    2010-01-01

    Genetic rescue has been proposed as a management strategy to improve the fitness of genetically eroded populations by alleviating inbreeding depression. We studied the dynamics of genetic rescue in inbred populations of Drosophila. Using balancer chromosomes, we show that the force of heterosis that

  14. Body saccades of Drosophila consist of stereotyped banked turns

    NARCIS (Netherlands)

    Muijres, F.T.; Elzinga, M.J.; Iwasaki, N.A.; Dickinson, M.H.

    2015-01-01

    The flight pattern of many fly species consists of straight flight segments interspersed with rapid turns called body saccades, a strategy that is thought to minimize motion blur. We analyzed the body saccades of fruit flies (Drosophila hydei), using high-speed 3D videography to track body and wing

  15. Detecting novel low-abundant transcripts in Drosophila

    DEFF Research Database (Denmark)

    Lee, Sanggyu; Bao, Jingyue; Zhou, Guolin;

    2005-01-01

    Increasing evidence suggests that low-abundant transcripts may play fundamental roles in biological processes. In an attempt to estimate the prevalence of low-abundant transcripts in eukaryotic genomes, we performed a transcriptome analysis in Drosophila using the SAGE technique. We collected 244...

  16. Neurogenetics of female reproductive behaviors in Drosophila melanogaster

    NARCIS (Netherlands)

    Laturney, Meghan; Billeter, Jean-Christophe; Friedmann, T; Dunlap, JC; Goodwin, SF

    2014-01-01

    We follow an adult Drosophila melanogaster female through the major reproductive decisions she makes during her lifetime, including habitat selection, precopulatory mate choice, postcopulatory physiological changes, polyandry, and egg-laying site selection. In the process, we review the molecular an

  17. Analysis of resistance and tolerance to virus infection in Drosophila

    NARCIS (Netherlands)

    Merkling, S.H.; Rij, R.P. van

    2015-01-01

    Host defense to virus infection involves both resistance mechanisms that reduce viral burden and tolerance mechanisms that limit detrimental effects of infection. The fruit fly, Drosophila melanogaster, has emerged as a model for identifying and characterizing the genetic basis of resistance and tol

  18. Heat shock protection against cold stress of Drosophila melanogaster.

    OpenAIRE

    Burton, V; Mitchell, H K; Young, P.; Petersen, N S

    1988-01-01

    Heat shock protein synthesis can be induced during recovery from cold treatment of Drosophila melanogaster larvae. Survival of larvae after a cold treatment is dramatically improved by a mild heat shock just before the cold shock. The conditions which induce tolerance to cold are similar to those which confer tolerance to heat.

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

    Directory of Open Access Journals (Sweden)

    Nieves Baenas

    2016-02-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  1. EGFR signaling regulates the proliferation of Drosophila adult midgut progenitors

    OpenAIRE

    Jiang, Huaqi; Edgar, Bruce A.

    2009-01-01

    In holometabolous insects, the adult appendages and internal organs form anew from larval progenitor cells during metamorphosis. As described here, the adult Drosophila midgut, including intestinal stem cells (ISCs), develops from adult midgut progenitor cells (AMPs) that proliferate during larval development in two phases. Dividing AMPs first disperse, but later proliferate within distinct islands, forming large cell clusters that eventually fuse during metamorphosis ...

  2. The olfactory circuit of the fruit fly Drosophila melanogaster

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The olfactory circuit of the fruit fly Drosophila melanogaster has emerged in recent years as an excellent paradigm for studying the principles and mechanisms of information processing in neuronal circuits. We discuss here the organizational principles of the olfactory circuit that make it an attractive model for experimental manipulations, the lessons that have been learned, and future challenges.

  3. Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila

    Science.gov (United States)

    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

  4. Actin puts the squeeze on Drosophila glue secretion.

    Science.gov (United States)

    Merrifield, Christien J

    2016-02-01

    An actin filament coat promotes cargo expulsion from large exocytosing vesicles, but the mechanisms of coat formation and force generation have been poorly characterized. Elegant imaging studies of the Drosophila melanogaster salivary gland now reveal how actin and myosin are recruited, and show that myosin II forms a contractile 'cage' that facilitates exocytosis.

  5. Drosophila phosphopantothenoylcysteine synthetase is required for tissue morphogenesis during oogenesis

    NARCIS (Netherlands)

    Bosveld, Floris; Rana, Anil; Lemstra - Wierenga, Willemina; Kampinga, Harm; Sibon, Ody

    2008-01-01

    Background: Coenzyme A (CoA) is an essential metabolite, synthesized from vitamin B5 by the subsequent action of five enzymes: PANK, PPCS, PPCDC, PPAT and DPCK. Mutations in Drosophila dPPCS disrupt female fecundity and in this study we analyzed the female sterile phenotype of dPPCS mutants in detai

  6. Characterization and manipulation of fruit susceptibility to Drosophila suzukii

    Science.gov (United States)

    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 ...

  7. Fluctuation-Driven Neural Dynamics Reproduce Drosophila Locomotor Patterns.

    Directory of Open Access Journals (Sweden)

    Andrea Maesani

    2015-11-01

    Full Text Available 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.

  8. Integrating computational biology and forward genetics in Drosophila.

    Directory of Open Access Journals (Sweden)

    Stein Aerts

    2009-01-01

    Full Text Available Genetic screens are powerful methods for the discovery of gene-phenotype associations. However, a systems biology approach to genetics must leverage the massive amount of "omics" data to enhance the power and speed of functional gene discovery in vivo. Thus far, few computational methods for gene function prediction have been rigorously tested for their performance on a genome-wide scale in vivo. In this work, we demonstrate that integrating genome-wide computational gene prioritization with large-scale genetic screening is a powerful tool for functional gene discovery. To discover genes involved in neural development in Drosophila, we extend our strategy for the prioritization of human candidate disease genes to functional prioritization in Drosophila. We then integrate this prioritization strategy with a large-scale genetic screen for interactors of the proneural transcription factor Atonal using genomic deficiencies and mutant and RNAi collections. Using the prioritized genes validated in our genetic screen, we describe a novel genetic interaction network for Atonal. Lastly, we prioritize the whole Drosophila genome and identify candidate gene associations for ten receptor-signaling pathways. This novel database of prioritized pathway candidates, as well as a web application for functional prioritization in Drosophila, called Endeavour-HighFly, and the Atonal network, are publicly available resources. A systems genetics approach that combines the power of computational predictions with in vivo genetic screens strongly enhances the process of gene function and gene-gene association discovery.

  9. The metabolic profile of long-lived Drosophila melanogaster

    DEFF Research Database (Denmark)

    Sarup, Pernille Merete; Pedersen, Simon Metz; Nielsen, Niels Christian;

    2012-01-01

    We investigated the age-related changes in the metabolic profile of male Drosophila melanogaster and compared the metabolic profile of flies selected for increased longevity to that of control flies of equal age. We found clear differences in metabolite composition between selection regimes and a...

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

    Directory of Open Access Journals (Sweden)

    Rebekah L Rogers

    Full Text Available 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.

  11. Sucrose Improves Insecticide Activity Against Drosophila suzukii (Diptera: Drosophilidae).

    Science.gov (United States)

    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%.

  12. Image tracking study on courtship behavior of Drosophila.

    Directory of Open Access Journals (Sweden)

    Hung-Yin Tsai

    Full Text Available BACKGROUND: In recent years, there have been extensive studies aimed at decoding the DNA. Identifying the genetic cause of specific changes in a simple organism like Drosophila may help scientists recognize how multiple gene interactions may make some people more susceptible to heart disease or cancer. Investigators have devised experiments to observe changes in the gene networks in mutant Drosophila that responds differently to light, or have lower or higher locomotor activity. However, these studies focused on the behavior of the individual fly or on pair-wise interactions in the study of aggression or courtship. The behavior of these activities has been captured on film and inspected by a well-trained researcher after repeatedly watching the recorded film. Some studies also focused on ways to reduce the inspection time and increase the accuracy of the behavior experiment. METHODOLOGY: In this study, the behavior of drosophila during courtship was analyzed automatically by machine vision. We investigated the position and behavior discrimination during courtship using the captured images. Identification of the characteristics of drosophila, including sex, size, heading direction, and wing angles, can be computed using image analysis techniques that employ the Gaussian mixture model. The behavior of multiple drosophilae can also be analyzed simultaneously using the motion-prediction model and the variation constraint of heading direction. CONCLUSIONS: The overlapped fruit flies can be identified based on the relationship between body centers. Moreover, the behaviors and profiles can be correctly recognized by image processing based on the constraints of the wing angle and the size of the body. Therefore, the behavior of the male fruit flies can be discriminated when two or three fruit flies form a close cluster. In this study, the courtship behavior, including wing songs and attempts, can currently be distinguished with accuracies of 95.8% and

  13. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, M.K.; Shamoun, B.I.; Bonazza, R.; Corradini, M.L. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics

    1998-01-01

    Stratified Fuel-Coolant Interaction (FCI) experiments with Refrigerant-134a and water were performed in a large-scale system. Air was uniformly injected into the coolant pool to establish a pre-existing void which could suppress the explosion. Two competing effects due to the variation of the air flow rate seem to influence the intensity of the explosion in this geometrical configuration. At low flow rates, although the injected air increases the void fraction, the concurrent agitation and mixing increases the intensity of the interaction. At higher flow rates, the increase in void fraction tends to attenuate the propagated pressure wave generated by the explosion. Experimental results show a complete suppression of the vapor explosion at high rates of air injection, corresponding to an average void fraction of larger than 30%. (author)

  14. Chk1 suppressed cell death

    Directory of Open Access Journals (Sweden)

    Meuth Mark

    2010-09-01

    Full Text Available Abstract The role of Chk1 in the cellular response to DNA replication stress is well established. However recent work indicates a novel role for Chk1 in the suppression of apoptosis following the disruption of DNA replication or DNA damage. This review will consider these findings in the context of known pathways of Chk1 signalling and potential applications of therapies that target Chk1.

  15. Visual Surround Suppression in Schizophrenia

    OpenAIRE

    Tibber, Marc S.; Elaine J Anderson; Bobin, Tracy; Antonova, Elena; Seabright, Alice; Wright, Bernice; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast – a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the targ...

  16. Visual surround suppression in schizophrenia

    OpenAIRE

    Marc Samuel Tibber; Elaine J Anderson; Tracy eBobin; Elena eAntonova; Alice eSeabright; Bernice eWright; Patricia eCarlin; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the tar...

  17. Jet Suppression Measured in ATLAS

    CERN Document Server

    Citron, Zvi Hirsh; The ATLAS collaboration

    2015-01-01

    In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced, and jets propagating through this medium are known to suffer energy loss. This results in a lower yield of jets emerging from the medium than expected in the absence of medium effects, and thus modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. Parton showers initiated by quarks tend to have fewer fragments carrying a larger fraction of the total jet energy than those resulting from gluons. In this talk, the latest ATLAS results on single jet suppression will be presented. Measurements of the nuclear modification factor, RAA, for fully reconstructed jets are shown. The rapidity dependence of jet suppression is discussed, which is sensitive to the relative energy loss between quark and gluon jets. New measurements of single hadron suppression out to pT~150 GeV ...

  18. FLUTTER SUPPRESSION USING DISTRIBUTEDPIEZOELECTRIC ACTUATORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A piezoelectric actuator has the benefits of flexibility of its position, without time lag and wide bandpass characteristics. The early results of the wind tunnel flutter suppression test using the piezoeletric actuator were presented in Ref.[1]. A rigid rectangular wing model is constrained by a plunge spring and a pitch spring, and a pair of piezoelectric actuators is bonded on both sides of the plunge spring so as to carry out the active control. Refs.[2,3] reported two flutter suppression wind tunnel tests where the distributed piezoelectric actuators were used. In Ref.[2] low speed wind tunnel tests were conducted with aluminum and composite plate-like rectangular models fully covered by piezoelectric actuators. Flutter speed is increased by 11%. In Ref.[3] a composite plate-like swept back model with piezoceramic actuators bonded on the inboard surface was tested in a transonic wind tunnel and a 12% increment of flutter dynamic pressure was achieved.  In the present investigation, an aluminum plate-like rectangular model with inboard bonded piezoceramic actuators is adopted. Active flutter suppression control law has been designed. A series of analyses and ground tests and, finally, low-speed wind tunnel tests with the active control system opened and closed are conducted. Reasonable results have been obtained.

  19. Proprioceptive feedback determines visuomotor gain in Drosophila.

    Science.gov (United States)

    Bartussek, Jan; Lehmann, Fritz-Olaf

    2016-01-01

    Multisensory integration is a prerequisite for effective locomotor control in most animals. Especially, the impressive aerial performance of insects relies on rapid and precise integration of multiple sensory modalities that provide feedback on different time scales. In flies, continuous visual signalling from the compound eyes is fused with phasic proprioceptive feedback to ensure precise neural activation of wing steering muscles (WSM) within narrow temporal phase bands of the stroke cycle. This phase-locked activation relies on mechanoreceptors distributed over wings and gyroscopic halteres. Here we investigate visual steering performance of tethered flying fruit flies with reduced haltere and wing feedback signalling. Using a flight simulator, we evaluated visual object fixation behaviour, optomotor altitude control and saccadic escape reflexes. The behavioural assays show an antagonistic effect of wing and haltere signalling on visuomotor gain during flight. Compared with controls, suppression of haltere feedback attenuates while suppression of wing feedback enhances the animal's wing steering range. Our results suggest that the generation of motor commands owing to visual perception is dynamically controlled by proprioception. We outline a potential physiological mechanism based on the biomechanical properties of WSM and sensory integration processes at the level of motoneurons. Collectively, the findings contribute to our general understanding how moving animals integrate sensory information with dynamically changing temporal structure. PMID:26909184

  20. High sucrose consumption promotes obesity whereas its low consumption induces oxidative stress in Drosophila melanogaster.

    Science.gov (United States)

    Rovenko, Bohdana M; Kubrak, Olga I; Gospodaryov, Dmytro V; Perkhulyn, Natalia V; Yurkevych, Ihor S; Sanz, Alberto; Lushchak, Oleh V; Lushchak, Volodymyr I

    2015-08-01

    The effects of sucrose in varied concentrations (0.25-20%) with constant amount of yeasts in larval diet on development and metabolic parameters of adult fruit fly Drosophila melanogaster were studied. Larvae consumed more food at low sucrose diet, overeating with yeast. On high sucrose diet, larvae ingested more carbohydrates, despite consuming less food and obtaining less protein derived from yeast. High sucrose diet slowed down pupation and increased pupa mortality, enhanced levels of lipids and glycogen, increased dry body mass, decreased water content, i.e. resulted in obese phenotype. Furthermore, it suppressed reactive oxygen species-induced oxidation of lipids and proteins as well as the activity of superoxide dismutase. The activity of catalase was gender-related. In males, at all sucrose concentrations used catalase activity was higher than at its concentration of 0.25%, whereas in females sucrose concentration virtually did not influence the activity. High sucrose diet increased content of protein thiols and the activity of glucose-6-phosphate dehydrogenase. The increase in sucrose concentration also enhanced uric acid level in females, but caused opposite effects in males. Development on high sucrose diets was accompanied by elevated steady-state insulin-like peptide 3 mRNA level. Finally, carbohydrate starvation at yeast overfeeding on low sucrose diets resulted in oxidative stress reflected by higher levels of oxidized lipids and proteins accompanied by increased superoxide dismutase activity. Potential mechanisms involved in regulation of redox processes by carbohydrates are discussed.

  1. Behavioural analyses of quinine processing in choice, feeding and learning of larval Drosophila.

    Directory of Open Access Journals (Sweden)

    Amira El-Keredy

    Full Text Available Gustatory stimuli can support both immediate reflexive behaviour, such as choice and feeding, and can drive internal reinforcement in associative learning. For larval Drosophila, we here provide a first systematic behavioural analysis of these functions with respect to quinine as a study case of a substance which humans report as "tasting bitter". We describe the dose-effect functions for these different kinds of behaviour and find that a half-maximal effect of quinine to suppress feeding needs substantially higher quinine concentrations (2.0 mM than is the case for internal reinforcement (0.6 mM. Interestingly, in previous studies (Niewalda et al. 2008, Schipanski et al 2008 we had found the reverse for sodium chloride and fructose/sucrose, such that dose-effect functions for those tastants were shifted towards lower concentrations for feeding as compared to reinforcement, arguing that the differences in dose-effect function between these behaviours do not reflect artefacts of the types of assay used. The current results regarding quinine thus provide a starting point to investigate how the gustatory system is organized on the cellular and/or molecular level to result in different behavioural tuning curves towards a bitter tastant.

  2. Antimutagenic effect of sage tea in the wing spot test of Drosophila melanogaster.

    Science.gov (United States)

    Patenkovic, Aleksandra; Stamenkovic-Radak, Marina; Banjanac, Tijana; Andjelkovic, Marko

    2009-01-01

    The present study assayed the antimutagenic potential of Salvia officinalis (sage) in the form of tea infusion, by the somatic mutation and recombination test (SMART) on Drosophila melanogaster. The use of herbal infusions is much common in the human diet, so the aim of the present study was to estimate the antimutagenic effects of the S. officinalis tea rather than essential oils. Methyl methanesulphonate (MMS) was used as the mutagen and positive control. Several types of treatment were performed: short acute treatment with sage infusion or MMS, longer (chronic) treatment with sage solution or MMS, and two combined treatments, i.e. short treatment with sage followed by a longer treatment with MMS and vice versa. Sage infusion used in our experiments showed a clear antimutagenic effect, reducing the frequency of mutations induced by MMS. The inhibition effect of sage tea is obtained and confirmed when pre- or post-treatments with mutagen were used. The results indicate that although sage in this regime decreases the number of mutation events, it is not efficient enough in case of the 2 h sage pre-treatment. Antioxidant activity, suppression of metabolic activation, could be mechanisms through which sage or some of its components act as desmutagen.

  3. Functional domains and sub-cellular distribution of the Hedgehog transducing protein Smoothened in Drosophila.

    Science.gov (United States)

    Nakano, Y; Nystedt, S; Shivdasani, A A; Strutt, H; Thomas, C; Ingham, P W

    2004-06-01

    The Hedgehog signalling pathway is deployed repeatedly during normal animal development and its inappropriate activity is associated with various tumours in human. The serpentine protein Smoothened (Smo) is essential for cells to respond to the Hedeghog (Hh) signal; oncogenic forms of Smo have been isolated from human basal cell carcinomas. Despite similarities with ligand binding G-protein coupled receptors, the molecular basis of Smo activity and its regulation remains unclear. In non-responding cells, Smo is suppressed by the activity of another multipass membrane spanning protein Ptc, which acts as the Hh receptor. In Drosophila, binding of Hh to Ptc has been shown to cause an accumulation of phosphorylated Smo protein and a concomitant stabilisation of the activated form of the Ci transcription factor. Here, we identify domains essential for Smo activity and investigate the sub-cellular distribution of the wild type protein in vivo. We find that deletion of the amino terminus and the juxtamembrane region of the carboxy terminus of the protein result in the loss of normal Smo activity. Using Green Fluorescent Protein (GFP) and horseradish peroxidase fusion proteins we show that Smo accumulates in the plasma membrane of cells in which Ptc activity is abrogated by Hh but is targeted to the degradative pathway in cells where Ptc is active. We further demonstrate that Smo accumulation is likely to be a cause, rather than a consequence, of Hh signal transduction.

  4. Combover/CG10732, a novel PCP effector for Drosophila wing hair formation.

    Directory of Open Access Journals (Sweden)

    Jeremy K Fagan

    Full Text Available The polarization of cells is essential for the proper functioning of most organs. Planar Cell Polarity (PCP, the polarization within the plane of an epithelium, is perpendicular to apical-basal polarity and established by the non-canonical Wnt/Fz-PCP signaling pathway. Within each tissue, downstream PCP effectors link the signal to tissue specific readouts such as stereocilia orientation in the inner ear and hair follicle orientation in vertebrates or the polarization of ommatidia and wing hairs in Drosophila melanogaster. Specific PCP effectors in the wing such as Multiple wing hairs (Mwh and Rho Kinase (Rok are required to position the hair at the correct position and to prevent ectopic actin hairs. In a genome-wide screen in vitro, we identified Combover (Cmb/CG10732 as a novel Rho kinase substrate. Overexpression of Cmb causes the formation of a multiple hair cell phenotype (MHC, similar to loss of rok and mwh. This MHC phenotype is dominantly enhanced by removal of rok or of other members of the PCP effector gene family. Furthermore, we show that Cmb physically interacts with Mwh, and cmb null mutants suppress the MHC phenotype of mwh alleles. Our data indicate that Cmb is a novel PCP effector that promotes to wing hair formation, a function that is antagonized by Mwh.

  5. Synaptic abnormalities in a Drosophila model of Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Siddhita D. Mhatre

    2014-03-01

    Full Text Available Alzheimer’s disease (AD is an age-related neurodegenerative disease characterized by memory loss and decreased synaptic function. Advances in transgenic animal models of AD have facilitated our understanding of this disorder, and have aided in the development, speed and efficiency of testing potential therapeutics. Recently, we have described the characterization of a novel model of AD in the fruit fly, Drosophila melanogaster, where we expressed the human AD-associated proteins APP and BACE in the central nervous system of the fly. Here we describe synaptic defects in the larval neuromuscular junction (NMJ in this model. Our results indicate that expression of human APP and BACE at the larval NMJ leads to defective larval locomotion behavior, decreased presynaptic connections, altered mitochondrial localization in presynaptic motor neurons and decreased postsynaptic protein levels. Treating larvae expressing APP and BACE with the γ-secretase inhibitor L-685,458 suppresses the behavioral defects as well as the pre- and postsynaptic defects. We suggest that this model will be useful to assess and model the synaptic dysfunction normally associated with AD, and will also serve as a powerful in vivo tool for rapid testing of potential therapeutics for AD.

  6. High sucrose consumption promotes obesity whereas its low consumption induces oxidative stress in Drosophila melanogaster.

    Science.gov (United States)

    Rovenko, Bohdana M; Kubrak, Olga I; Gospodaryov, Dmytro V; Perkhulyn, Natalia V; Yurkevych, Ihor S; Sanz, Alberto; Lushchak, Oleh V; Lushchak, Volodymyr I

    2015-08-01

    The effects of sucrose in varied concentrations (0.25-20%) with constant amount of yeasts in larval diet on development and metabolic parameters of adult fruit fly Drosophila melanogaster were studied. Larvae consumed more food at low sucrose diet, overeating with yeast. On high sucrose diet, larvae ingested more carbohydrates, despite consuming less food and obtaining less protein derived from yeast. High sucrose diet slowed down pupation and increased pupa mortality, enhanced levels of lipids and glycogen, increased dry body mass, decreased water content, i.e. resulted in obese phenotype. Furthermore, it suppressed reactive oxygen species-induced oxidation of lipids and proteins as well as the activity of superoxide dismutase. The activity of catalase was gender-related. In males, at all sucrose concentrations used catalase activity was higher than at its concentration of 0.25%, whereas in females sucrose concentration virtually did not influence the activity. High sucrose diet increased content of protein thiols and the activity of glucose-6-phosphate dehydrogenase. The increase in sucrose concentration also enhanced uric acid level in females, but caused opposite effects in males. Development on high sucrose diets was accompanied by elevated steady-state insulin-like peptide 3 mRNA level. Finally, carbohydrate starvation at yeast overfeeding on low sucrose diets resulted in oxidative stress reflected by higher levels of oxidized lipids and proteins accompanied by increased superoxide dismutase activity. Potential mechanisms involved in regulation of redox processes by carbohydrates are discussed. PMID:26050918

  7. Characterization of the Drosophila Atlastin Interactome Reveals VCP as a Functionally Related Interactor

    Institute of Scientific and Technical Information of China (English)

    Niamh C.O'Sullivan; Nina Dr(a)ger; Cahir J.O'Kane

    2013-01-01

    At least 25 genes,many involved in trafficking,localisation or shaping of membrane organelles,have been identified as causative genes for the neurodegenerative disorder hereditary spastic paraplegia (HSP).One of the most commonly mutated HSP genes,atlastin-1,encodes a dynamin-like GTPase that mediates homotypic fusion of endoplasmic reticulum (ER) membranes.However,the molecular mechanisms of atlastin-l-related membrane fusion and axonopathy remain unclear.To better understand its mode of action,we used affinity purification coupled with mass spectrometry to identify protein interactors of atlastin in Drosophila.Analysis of 72 identified proteins revealed that the atlastin interactome contains many proteins involved in protein processing and transport,in addition to proteins with roles in mRNA binding,metabolism and mitochondrial proteins.The highest confidence interactor from mass spectrometry analysis,the ubiquitin-selective AAA-ATPase valosin-containing protein (VCP),was validated as an atlastin-interacting protein,and VCP and atlastin showed overlapping subcellular distributions.Furthermore,VCP acted as a genetic modifier of atlastin:loss of VCP partially suppressed an eye phenotype caused by atlastin overexpression,whereas overexpression of VCP enhanced this phenotype.These interactions between atlastin and VCP suggest a functional relationship between these two proteins,and point to potential shared mechanisms between HSP and other forms of neurodegeneration.

  8. Tailless and Atrophin control Drosophila aggression by regulating neuropeptide signalling in the pars intercerebralis

    Science.gov (United States)

    Davis, Shaun M.; Thomas, Amanda L.; Nomie, Krystle J.; Huang, Longwen; Dierick, Herman A.

    2014-02-01

    Aggressive behaviour is widespread throughout the animal kingdom. However, its mechanisms are poorly understood, and the degree of molecular conservation between distantly related species is unknown. Here we show that knockdown of tailless (tll) increases aggression in Drosophila, similar to the effect of its mouse orthologue Nr2e1. Tll localizes to the adult pars intercerebralis (PI), which shows similarity to the mammalian hypothalamus. Knockdown of tll in the PI is sufficient to increase aggression and is rescued by co-expressing human NR2E1. Knockdown of Atrophin, a Tll co-repressor, also increases aggression, and both proteins physically interact in the PI. tll knockdown-induced aggression is fully suppressed by blocking neuropeptide processing or release from the PI. In addition, genetically activating PI neurons increases aggression, mimicking the aggression-inducing effect of hypothalamic stimulation. Together, our results suggest that a transcriptional control module regulates neuropeptide signalling from the neurosecretory cells of the brain to control aggressive behaviour.

  9. Adaptive Filtering for Aeroservoelastic Response Suppression Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CSA Engineering proposes the design of an adaptive aeroelastic mode suppression for advanced fly-by-wire aircraft, which will partition the modal suppression...

  10. Continuous flash suppression reduces negative afterimages

    OpenAIRE

    Tsuchiya, Naotsugu; Koch, Christof

    2005-01-01

    Illusions that produce perceptual suppression despite constant retinal input are used to manipulate visual consciousness. Here we report on a powerful variant of existing techniques, continuous flash suppression. Distinct images flashed successively at approx10 Hz into one eye reliably suppress an image presented to the other eye. The duration of perceptual suppression is at least ten times greater than that produced by binocular rivalry. Using this tool we show that the strength of the negat...

  11. Regulation of Sleep by Neuropeptide Y-Like System in Drosophila melanogaster

    OpenAIRE

    Chunxia He; Yunyan Yang; Mingming Zhang; Price, Jeffrey L.; Zhangwu Zhao

    2013-01-01

    Sleep is important for maintenance of normal physiology in animals. In mammals, neuropeptide Y (NPY), a homolog of Drosophila neuropeptide F (NPF), is involved in sleep regulation, with different effects in human and rat. However, the function of NPF on sleep in Drosophila melanogaster has not yet been described. In this study, we investigated the effects of NPF and its receptor-neuropeptide F receptor (NPFR1) on Drosophila sleep. Male flies over-expressing NPF or NPFR1 exhibited increased sl...

  12. Identification and Characterization of Genes Involved in Embryonic Crystal Cell Formation During Drosophila Hematopoiesis

    OpenAIRE

    Milchanowski, Allison B.; Henkenius, Amy L.; Narayanan, Maya; Hartenstein, Volker; Banerjee, Utpal

    2004-01-01

    Parallels between vertebrate and Drosophila hematopoiesis add to the value of flies as a model organism to gain insights into blood development. The Drosophila hematopoietic system is composed of at least three classes of terminally differentiated blood cells: plasmatocytes, crystal cells, and lamellocytes. Recent studies have identified transcriptional and signaling pathways in Drosophila involving proteins similar to those seen in human blood development. To identify additional genes involv...

  13. The Little Fly that Could: Wizardry and Artistry of Drosophila Genomics

    OpenAIRE

    Ejsmont, Radoslaw K.; Hassan, Bassem A.

    2014-01-01

    For more than 100 years now, the fruit fly Drosophila melanogaster has been at the forefront of our endeavors to unlock the secrets of the genome. From the pioneering studies of chromosomes and heredity by Morgan and his colleagues, to the generation of fly models for human disease, Drosophila research has been at the forefront of genetics and genomics. We present a broad overview of some of the most powerful genomics tools that keep Drosophila research at the cutting edge of modern biomedica...

  14. Dissecting muscle and neuronal disorders in a Drosophila model of muscular dystrophy.

    OpenAIRE

    Shcherbata, H.; Yatsenko, A.; Patterson, L; Sood, V.; Nudel, U; Yaffe, D; Baker, D.; Ruohola-Baker, H

    2007-01-01

    Perturbation in the Dystroglycan (Dg)–Dystrophin (Dys) complex results in muscular dystrophies and brain abnormalities in human. Here we report that Drosophila is an excellent genetically tractable model to study muscular dystrophies and neuronal abnormalities caused by defects in this complex. Using a fluorescence polarization assay, we show a high conservation in Dg–Dys interaction between human and Drosophila. Genetic and RNAi-induced perturbations of Dg and Dys in Drosophila cause cell po...

  15. Drosophila Kelch functions with Cullin-3 to organize the ring canal actin cytoskeleton

    OpenAIRE

    Hudson, Andrew M.; Cooley, Lynn

    2010-01-01

    Drosophila melanogaster Kelch (KEL) is the founding member of a diverse protein family defined by a repeated sequence motif known as the KEL repeat (KREP). Several KREP proteins, including Drosophila KEL, bind filamentous actin (F-actin) and contribute to its organization. Recently, a subset of KREP proteins has been shown to function as substrate adaptor proteins for cullin-RING (really interesting new gene) ubiquitin E3 ligases. In this study, we demonstrate that association of Drosophila K...

  16. Genotoxic activity in vivo of the naturally occurring glucoside, cycasin, in the Drosophila wing spot test.

    Science.gov (United States)

    Kawai, K; Furukawa, H; Hirono, I

    1995-03-01

    Cycasin, methylazoxymethanol-beta-glucoside, is a naturally occurring carcinogenic compound. The genotoxicity of cycasin was assayed in the Drosophila wing spot test. Cycasin induced small single and large single spots on feeding at 10 mumol/g medium. The presence of these spots indicates that cycasin is genotoxic in Drosophila melanogaster. Microorganisms which showed beta-glucosidase activity for cleaving cycasin to toxic aglycon were isolated from gut flora of the Drosophila larvae. Consequently, the Drosophila wing spot test would be useful for mutagenicity screening of other naturally occurring glucosides.

  17. Silver nanoparticle toxicity in Drosophila: size does matter

    Directory of Open Access Journals (Sweden)

    Deborah J Gorth

    2011-02-01

    Full Text Available Deborah J Gorth1, David M Rand2, Thomas J Webster11School of Engineering, 2Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, USABackground: Consumer nanotechnology is a growing industry. Silver nanoparticles are the most common nanomaterial added to commercially available products, so understanding the influence that size has on toxicity is integral to the safe use of these new products. This study examined the influence of silver particle size on Drosophila egg development by comparing the toxicity of both nanoscale and conventional-sized silver particles.Methods: The toxicity assays were conducted by exposing Drosophila eggs to particle concentrations ranging from 10 ppm to 100 ppm of silver. Size, chemistry, and agglomeration of the silver particles were evaluated using transmission electron microscopy, X-ray photoelectron spectroscopy, and dynamic light scattering.Results: This analysis confirmed individual silver particle sizes in the ranges of 20–30 nm, 100 nm, and 500–1200 nm, with similar chemistry. Dynamic light scattering and transmission electron microscope data also indicated agglomeration in water, with the transmission electron microscopic images showing individual particles in the correct size range, but the dynamic light scattering z-average sizes of the silver nanoparticles were 782 ± 379 nm for the 20–30 nm silver nanoparticles, 693 ± 114 nm for the 100 nm silver nanoparticles, and 508 ± 32 nm for the 500–1200 nm silver particles. Most importantly, here we show significantly more Drosophila egg toxicity when exposed to larger, nonnanometer silver particles. Upon exposure to silver nanoparticles sized 20–30 nm, Drosophila eggs did not exhibit a statistically significant (P < 0.05 decrease in their likelihood to pupate, but eggs exposed to larger silver particles (500–1200 nm were 91% ± 18% less likely to pupate. Exposure to silver nanoparticles reduced the percentage of pupae able

  18. Suppression effects on musical and verbal memory.

    Science.gov (United States)

    Schendel, Zachary A; Palmer, Caroline

    2007-06-01

    Three experiments contrasted the effects of articulatory suppression on recognition memory for musical and verbal sequences. In Experiment 1, a standard/comparison task was employed, with digit or note sequences presented visually or auditorily while participants remained silent or produced intermittent verbal suppression (saying "the") or musical suppression (singing "la"). Both suppression types decreased performance by equivalent amounts, as compared with no suppression. Recognition accuracy was lower during suppression for visually presented digits than during that for auditorily presented digits (consistent with phonological loop predictions), whereas accuracy was equivalent for visually presented notes and auditory tones. When visual interference filled the retention interval in Experiment 2, performance with visually presented notes but not digits was impaired. Experiment 3 forced participants to translate visually presented music sequences by presenting comparison sequences auditorily. Suppression effects for visually presented music resembled those for digits only when the recognition task required sensory translation of cues. PMID:17848022

  19. Sleep, aging, and lifespan in Drosophila

    Directory of Open Access Journals (Sweden)

    Tononi Giulio

    2010-04-01

    Full Text Available Abstract Background Epidemiological studies in humans suggest that a decrease in daily sleep duration is associated with reduced lifespan, but this issue remains controversial. Other studies in humans also show that both sleep quantity and sleep quality decrease with age. Drosophila melanogaster is a useful model to study aging and sleep, and inheriting mutations affecting the potassium current Shaker results in flies that sleep less and have a shorter lifespan. However, whether the link between short sleep and reduced longevity exists also in wild-type flies is unknown. Similarly, it is unknown whether such a link depends on sleep amount per se, rather than on other factors such as waking activity. Also, sleep quality has been shown to decrease in old flies, but it remains unclear whether aging-related sleep fragmentation is a generalized phenomenon. Results We compared 3 short sleeping mutant lines (Hk1, HkY and Hk2 carrying a mutation in Hyperkinetic, which codes for the beta subunit of the Shaker channel, to wild-type siblings throughout their entire lifespan (all flies kept at 20°C. Hk1 and HkY mutants were short sleeping relative to wild-type controls from day 3 after eclosure, and Hk2 flies became short sleepers about two weeks later. All 3 Hk mutant lines had reduced lifespan relative to wild-type flies. Total sleep time showed a trend to increase in all lines with age, but the effect was most pronounced in Hk1 and HkY flies. In both mutant and wild-type lines sleep quality did not decay with age, but the strong preference for sleep at night declined starting in "middle age". Using Cox regression analysis we found that in Hk1 and HkY mutants and their control lines there was a negative relationship between total sleep amount during the first 2 and 4 weeks of age and hazard (individual risk of death, while no association was found in Hk2 flies and their wild-type controls. Hk1 and HkY mutants and their control lines also showed an

  20. Alcohol interacts with genetic alteration of the Hippo tumor suppressor pathway to modulate tissue growth in Drosophila.

    Directory of Open Access Journals (Sweden)

    Anoj Ilanges

    Full Text Available Alcohol-mediated cancers represent more than 3.5% of cancer-related deaths, yet how alcohol promotes cancer is a major open question. Using Drosophila, we identified novel interactions between dietary ethanol and loss of tumor suppressor components of the Hippo Pathway. The Hippo Pathway suppresses tumors in flies and mammals by inactivating transcriptional co-activator Yorkie, and the spectrum of cancers associated with impaired Hippo signaling overlaps strikingly with those associated with alcohol. Therefore, our findings may implicate loss of Hippo Pathway tumor suppression in alcohol-mediated cancers. Ethanol enhanced overgrowth from loss of the expanded, hippo, or warts tumor suppressors but, surprisingly, not from over-expressing the yorkie oncogene. We propose that in parallel to Yorkie-dependent overgrowth, impairing Hippo signaling in the presence of alcohol may promote overgrowth via additional alcohol-relevant targets. We also identified interactions between alcohol and Hippo Pathway over-activation. We propose that exceeding certain thresholds of alcohol exposure activates Hippo signaling to maintain proper growth control and prevent alcohol-mediated mis-patterning and tissue overgrowth.

  1. Ultrastructural examination of the insemination reaction in Drosophila.

    Science.gov (United States)

    Alonso-Pimentel, H; Tolbert, L P; Heed, W B

    1994-03-01

    The insemination reaction is a swelling of the female vagina caused by the male ejaculate. This postmating phenomenon is common among species in the genus Drosophila. It could act as a plug securing male paternity. It is not clear, however, what benefits it provides to the female. The structure formed in the female vagina is expelled in some species and disappears gradually in others suggesting different phenomena. Based on ultrastructural examination of the vaginal contents of five Drosophila species (D. mettleri, D. nigrospiracula, D. melanogaster, D. mojavensis, and D. hexastigma), we propose three terms to describe these vaginal structures: the sperm sac, the mating plug, and the true insemination reaction. Each term describes a distinct structure associated with a specific female postmating behavior. This study questions the concept of the insemination reaction as a single phenomenon and discusses its possible functions from an evolutionary perspective. PMID:8137397

  2. Drosophila melanogaster as a Model Organism of Brain Diseases

    Directory of Open Access Journals (Sweden)

    Werner Paulus

    2009-02-01

    Full Text Available Drosophila melanogaster has been utilized to model human brain diseases. In most of these invertebrate transgenic models, some aspects of human disease are reproduced. Although investigation of rodent models has been of significant impact, invertebrate models offer a wide variety of experimental tools that can potentially address some of the outstanding questions underlying neurological disease. This review considers what has been gleaned from invertebrate models of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, metabolic diseases such as Leigh disease, Niemann-Pick disease and ceroid lipofuscinoses, tumor syndromes such as neurofibromatosis and tuberous sclerosis, epilepsy as well as CNS injury. It is to be expected that genetic tools in Drosophila will reveal new pathways and interactions, which hopefully will result in molecular based therapy approaches.

  3. Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila

    Indian Academy of Sciences (India)

    Yuuichi Seki; Teiichi Tanimura

    2014-09-01

    A diverse range of organisms shows physiological and behavioural rhythms with various periods. Extensive studies have been performed to elucidate the molecular mechanisms of circadian rhythms with an approximately 24 h period in both Drosophila and mammals, while less attention has been paid to ultradian rhythms with shorter periods. We used a video-tracking method to monitor the movement of single flies, and clear ultradian rhythms were detected in the locomotor behaviour of wild type and clock mutant flies kept under constant dark conditions. In particular, the Pigment-dispersing factor mutant (Pdf01) demonstrated a precise and robust ultradian rhythmicity, which was not temperature compensated. Our results suggest that Drosophila has an endogenous ultradian oscillator that is masked by circadian rhythmic behaviours.

  4. Cas9-Mediated Genome Engineering in Drosophila melanogaster.

    Science.gov (United States)

    Housden, Benjamin E; Perrimon, Norbert

    2016-01-01

    The recent development of the CRISPR-Cas9 system for genome engineering has revolutionized our ability to modify the endogenous DNA sequence of many organisms, including Drosophila This system allows alteration of DNA sequences in situ with single base-pair precision and is now being used for a wide variety of applications. To use the CRISPR system effectively, various design parameters must be considered, including single guide RNA target site selection and identification of successful editing events. Here, we review recent advances in CRISPR methodology in Drosophila and introduce protocols for some of the more difficult aspects of CRISPR implementation: designing and generating CRISPR reagents and detecting indel mutations by high-resolution melt analysis. PMID:27587786

  5. Phenotypic inheritance induced by hairpin RNA in Drosophila

    Institute of Scientific and Technical Information of China (English)

    Huaguang Li; Yi Lu

    2009-01-01

    Phenotypic inheritance induced by RNA has been docu-mented in mouse and Caenorhabditis elegans. Here we report a similar inheritance in Drosophila. Mutant phe-notypes of eye defects and antenna duplication gener-ated from the crossing of one RNA interference (RNAi)transgenic line harboring one hairpin RNA transgene with a GAL4 driver line were inherited independently of the GAL4 driver. Hairpin RNA injection exper-iments demonstrated that the hairpin RNA could induce heritable mutant-like phenotypes on the eye and antenna. The penetrance of mutant phenotypes was reduced when the mutants were crossed to agol and piwi mutants. Our data suggest that hairpin RNA can induce phenotypic inheritance in Drosophila.

  6. Fluorescent visualization of macromolecules in Drosophila whole mounts.

    Science.gov (United States)

    Ramos, Ricardo Guelerman Pinheiro; Machado, Luciana Claudia Herculano; Moda, Livia Maria Rosatto

    2010-01-01

    The ability to determine the expression dynamics of individual genes "in situ" by visualizing the precise spatial and temporal distribution of their products in whole mounts by histochemical and immunocytochemical reactions has revolutionized our understanding of cellular processes. Drosophila developmental genetics was one of the fields that benefited most from these technologies, and a variety of fluorescent methods were specifically designed for investigating the localization of developmentally important proteins and cell markers during embryonic and post embryonic stages of this model organism. In this chapter we present detailed protocols for fluorescence immunocytochemistry of whole mount embryos, imaginal discs, pupal retinas, and salivary glands of Drosophila melanogaster, as well as methods for fluorescent visualization of specific subcellular structures in these tissues. PMID:20012830

  7. A quantitative method to analyze Drosophila pupal eye patterning.

    Directory of Open Access Journals (Sweden)

    Ruth I Johnson

    Full Text Available BACKGROUND: The Drosophila pupal eye has become a popular paradigm for understanding morphogenesis and tissue patterning. Correct rearrangement of cells between ommatidia is required to organize the ommatidial array across the eye field. This requires cell movement, cell death, changes to cell-cell adhesion, signaling and fate specification. METHODOLOGY: We describe a method to quantitatively assess mis-patterning of the Drosophila pupal eye and objectively calculate a 'mis-patterning score' characteristic of a specific genotype. This entails step-by-step scoring of specific traits observed in pupal eyes dissected 40-42 hours after puparium formation and subsequent statistical analysis of this data. SIGNIFICANCE: This method provides an unbiased quantitative score of mis-patterning severity that can be used to compare the impact of different genetic mutations on tissue patterning.

  8. Fluorescent visualization of macromolecules in Drosophila whole mounts.

    Science.gov (United States)

    Ramos, Ricardo Guelerman Pinheiro; Machado, Luciana Claudia Herculano; Moda, Livia Maria Rosatto

    2010-01-01

    The ability to determine the expression dynamics of individual genes "in situ" by visualizing the precise spatial and temporal distribution of their products in whole mounts by histochemical and immunocytochemical reactions has revolutionized our understanding of cellular processes. Drosophila developmental genetics was one of the fields that benefited most from these technologies, and a variety of fluorescent methods were specifically designed for investigating the localization of developmentally important proteins and cell markers during embryonic and post embryonic stages of this model organism. In this chapter we present detailed protocols for fluorescence immunocytochemistry of whole mount embryos, imaginal discs, pupal retinas, and salivary glands of Drosophila melanogaster, as well as methods for fluorescent visualization of specific subcellular structures in these tissues.

  9. Transcriptional profiling of apoptosis-deficient Drosophila mutants

    Directory of Open Access Journals (Sweden)

    Fumiaki Obata

    2014-12-01

    Full Text Available Apoptosis is a fundamental way to remove damaged or unwanted cells during both developmental and post-developmental stages. Apoptosis deficiency leads to various diseases including cancer. To know the physiological changes in apoptosis-deficient mutants, we conducted non-biased transcriptomic analysis of Drosophila darkcd4 mutants. As recently reported, combined with metabolome and genetic analysis, we identified systemic immune response, energy wasting, as well as alteration in S-adenosyl-methionine metabolism in response to necrotic cells [1]. Here, we describe in detail how we obtained validated microarray dataset deposited in Gene Expression Omnibus (GSE47853. Our data provide a resource for searching transcriptional alterations in Drosophila apoptosis-deficient mutants.

  10. Learning the specific quality of taste reinforcement in larval Drosophila.

    Science.gov (United States)

    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.

  11. Circadian Organization of Behavior and Physiology in Drosophila

    Science.gov (United States)

    Allada, Ravi; Chung, Brian Y.

    2010-01-01

    Circadian clocks organize behavior and physiology to adapt to daily environmental cycles. Genetic approaches in the fruit fly, Drosophila melanogaster, have revealed widely conserved molecular gears of these 24-h timers. Yet much less is known about how these cell-autonomous clocks confer temporal information to modulate cellular functions. Here we discuss our current knowledge of circadian clock function in Drosophila, providing an overview of the molecular underpinnings of circadian clocks. We then describe the neural network important for circadian rhythms of locomotor activity, including how these molecular clocks might influence neuronal function. Finally, we address a range of behaviors and physiological systems regulated by circadian clocks, including discussion of specific peripheral oscillators and key molecular effectors where they have been described. These studies reveal a remarkable complexity to circadian pathways in this “simple” model organism. PMID:20148690

  12. Immune stimulation reduces sleep and memory ability in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Eamonn B. Mallon

    2014-06-01

    Full Text Available Psychoneuroimmunology studies the increasing number of connections between neurobiology, immunology and behaviour. We demonstrate the effects of the immune response on two fundamental behaviours: sleep and memory ability in Drosophila melanogaster. We used the Geneswitch system to upregulate peptidoglycan receptor protein (PGRP expression, thereby stimulating the immune system in the absence of infection. Geneswitch was activated by feeding the steroid RU486, to the flies. We used an aversive classical conditioning paradigm to quantify memory and measures of activity to infer sleep. Immune stimulated flies exhibited reduced levels of sleep, which could not be explained by a generalised increase in waking activity. Immune stimulated flies also showed a reduction in memory abilities. These results lend support to Drosophila as a model for immune–neural interactions and provide a possible role for sleep in the interplay between the immune response and memory.

  13. Mal/SRF is dispensable for cell proliferation in Drosophila.

    Directory of Open Access Journals (Sweden)

    Barry J Thompson

    Full Text Available The Mal/SRF transcription factor is regulated by the level of G-actin in cells and has important roles in cell migration and other actin-dependent processes in Drosophila. A recent report suggests that Mal/SRF and an upstream regulator, Pico, are required for cell proliferation and tissue growth in Drosophila. I find otherwise. Mutation of Mal or SRF does not affect cell proliferation in the fly wing. Furthermore, I cannot reproduce the reported effects of Pico RNAi or Pico overexpression on body size. Nevertheless, I can confirm that overexpression of Pico or Mal causes tissue overgrowth specifically in the fly wing--where SRF is most highly expressed. My results indicate that Mal/SRF can promote tissue growth when abnormally active, but is not normally required for tissue growth during development.

  14. Drosophila Cancer Models Identify Functional Differences between Ret Fusions.

    Science.gov (United States)

    Levinson, Sarah; Cagan, Ross L

    2016-09-13

    We generated and compared Drosophila models of RET fusions CCDC6-RET and NCOA4-RET. Both RET fusions directed cells to migrate, delaminate, and undergo EMT, and both resulted in lethality when broadly expressed. In all phenotypes examined, NCOA4-RET was more severe than CCDC6-RET, mirroring their effects on patients. A functional screen against the Drosophila kinome and a library of cancer drugs found that CCDC6-RET and NCOA4-RET acted through different signaling networks and displayed distinct drug sensitivities. Combining data from the kinome and drug screens identified the WEE1 inhibitor AZD1775 plus the multi-kinase inhibitor sorafenib as a synergistic drug combination that is specific for NCOA4-RET. Our work emphasizes the importance of identifying and tailoring a patient's treatment to their specific RET fusion isoform and identifies a multi-targeted therapy that may prove effective against tumors containing the NCOA4-RET fusion. PMID:27626672

  15. Substrate vibrations during courtship in three Drosophila species.

    Directory of Open Access Journals (Sweden)

    Valerio Mazzoni

    Full Text Available While a plethora of studies have focused on the role of visual, chemical and near-field airborne signals in courtship of Drosophila fruit flies, the existence of substrate-borne vibrational signals has been almost completely overlooked. Here we describe substrate vibrations generated during courtship in three species of the D. melanogaster group, from the allegedly mute species D. suzukii, its sister species D. biarmipes, and from D. melanogaster. In all species, we recorded several types of substrate vibrations which were generated by locomotion, abdominal vibrations and most likely through the activity of thoracic wing muscles. In D. melanogaster and D. suzukii, all substrate vibrations described in intact males were also recorded in males with amputated wings. Evidence suggests that vibrational signalling may be widespread among Drosophila species, and fruit flies may provide an ideal model to study various aspects of this widespread form of animal communication.

  16. CRISPR/Cas9 and genome editing in Drosophila.

    Science.gov (United States)

    Bassett, Andrew R; Liu, Ji-Long

    2014-01-20

    Recent advances in our ability to design DNA binding factors with specificity for desired sequences have resulted in a revolution in genetic engineering, enabling directed changes to the genome to be made relatively easily. Traditional techniques for generating genetic mutations in most organisms have relied on selection from large pools of randomly induced mutations for those of particular interest, or time-consuming gene targeting by homologous recombination. Drosophila melanogaster has always been at the forefront of genetic analysis, and application of these new genome editing techniques to this organism will revolutionise our approach to performing analysis of gene function in the future. We discuss the recent techniques that apply the CRISPR/Cas9 system to Drosophila, highlight potential uses for this technology and speculate upon the future of genome engineering in this model organism.

  17. Separate TRP channels mediate amplification and transduction in drosophila

    Science.gov (United States)

    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.

  18. Effect of a magnetic field on Drosophila under supercooled conditions.

    Directory of Open Access Journals (Sweden)

    Munekazu Naito

    Full Text Available 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.

  19. Microbes Promote Amino Acid Harvest to Rescue Undernutrition in Drosophila

    Directory of Open Access Journals (Sweden)

    Ryuichi Yamada

    2015-02-01

    Full Text Available Microbes play an important role in the pathogenesis of nutritional disorders such as protein-specific malnutrition. However, the precise contribution of microbes to host energy balance during undernutrition is unclear. Here, we show that Issatchenkia orientalis, a fungal microbe isolated from field-caught Drosophila melanogaster, promotes amino acid harvest to rescue the lifespan of undernourished flies. Using radioisotope-labeled dietary components (amino acids, nucleotides, and sucrose to quantify nutrient transfer from food to microbe to fly, we demonstrate that I. orientalis extracts amino acids directly from nutrient-poor diets and increases protein flux to the fly. This microbial association restores body mass, protein, glycerol, and ATP levels and phenocopies the metabolic profile of adequately fed flies. Our study uncovers amino acid harvest as a fundamental mechanism linking microbial and host metabolism, and highlights Drosophila as a platform for quantitative studies of host-microbe relationships.

  20. Awakening to the behavioral analysis of sleep in Drosophila.

    Science.gov (United States)

    Shaw, Paul

    2003-02-01

    Perhaps the most observable of the many circadian oscillations that have been described in both vertebrate and invertebrate animals is the daily alterations in periods of rest and activity. Recent studies in the fruit fly Drosophila melanogaster suggest that these periods of inactivity are not simply rest but share many of the fundamental components that define mammalian sleep. Thus, quiescent episodes are characterized by reduced awareness of the environment and are homeostatically regulated. Although this field is in its infancy, recent studies have focused on the interaction between circadian and homeostatic processes. These results indicate that components of the circadian clock may play a substantial role in mechanisms underlying sleep homeostasis at the molecular level. In this article, the author reviews recent advances obtained using Drosophila as a model system to elucidate fundamental components of sleep regulation. PMID:12568240

  1. Learning the specific quality of taste reinforcement in larval Drosophila.

    Science.gov (United States)

    Schleyer, Michael; Miura, Daisuke; Tanimura, Teiichi; Gerber, Bertram

    2015-01-01

    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. PMID:25622533

  2. The multiple functions of the PGRP family in Drosophila immunity

    Directory of Open Access Journals (Sweden)

    A Goto

    2006-11-01

    Full Text Available The innate immune system discriminates between infectious non-self and self using germ-line-encoded pattern recognition receptors (PRRs that are highly conserved from insects to mammals. Peptidoglycan recognition protein (PGRP is one of the hallmark pattern recognition receptors responsible for detecting unique bacteria-derived peptidoglycans. The PGRP family comprises several members (13 in Drosophila, 7 in Anopheles, and 4 in mammals and are differentially expressed on immune-responsive organs. Some PGRPs have amidase or bactericidal activities and function as immune modulators, whereas others have lost their enzymatic activity, but still have crucial roles in the activation of innate immune signaling. Evidence from recent Drosophila studies suggests that PGRPs have a role in a variety of immune reactions, such as in the activation of the prophenoloxidase cascade, the production of antimicrobial peptides through the activation of the Toll and Imd pathways, intracellular bacteria recognition, and phagocytosis.

  3. A Drosophila systems model of pentylenetetrazole induced locomotor plasticity responsive to antiepileptic drugs

    Directory of Open Access Journals (Sweden)

    Singh Priyanka

    2009-01-01

    Full Text Available Abstract Background Rodent kindling induced by PTZ is a widely used model of epileptogenesis and AED testing. Overlapping pathophysiological mechanisms may underlie epileptogenesis and other neuropsychiatric conditions. Besides epilepsy, AEDs are widely used in treating various neuropsychiatric disorders. Mechanisms of AEDs' long term action in these disorders are poorly understood. We describe here a Drosophila systems model of PTZ induced locomotor plasticity that is responsive to AEDs. Results We empirically determined a regime in which seven days of PTZ treatment and seven days of subsequent PTZ discontinuation respectively cause a decrease and an increase in climbing speed of Drosophila adults. Concomitant treatment with NaVP and LEV, not ETH, GBP and VGB, suppressed the development of locomotor deficit at the end of chronic PTZ phase. Concomitant LEV also ameliorated locomotor alteration that develops after PTZ withdrawal. Time series of microarray expression profiles of heads of flies treated with PTZ for 12 hrs (beginning phase, two days (latent phase and seven days (behaviorally expressive phase showed only down-, not up-, regulation of genes; expression of 23, 2439 and 265 genes were downregulated, in that order. GO biological process enrichment analysis showed downregulation of transcription, neuron morphogenesis during differentiation, synaptic transmission, regulation of neurotransmitter levels, neurogenesis, axonogenesis, protein modification, axon guidance, actin filament organization etc. in the latent phase and of glutamate metabolism, cell communication etc. in the expressive phase. Proteomic interactome based analysis provided further directionality to these events. Pathway overrepresentation analysis showed enrichment of Wnt signaling and other associated pathways in genes downregulated by PTZ. Mining of available transcriptomic and proteomic data pertaining to established rodent models of epilepsy and human epileptic

  4. The Parthenogenetic Capacities and Genetic Structures of Sympatric Populations of DROSOPHILA MERCATORUM and DROSOPHILA HYDEI.

    Science.gov (United States)

    Templeton, A R

    1979-08-01

    Drosophila mercatorum is a sexual species that can reproduce parthenogenetically in the laboratory. A previous study showed that a natural population of D. mercatorum inhabiting the Kamuela garbage dump on the Island of Hawaii could produce both viable parthenogenetic adults and self-sustaining parthenogenetic lines. The present study deals with a second screen for parthenogenesis and an isozyme survey performed on natural populations of D. mercatorum and D. hydei caught in patches of Opuntia tuna about 10 kilometers from Kamuela. Both cactus-patch species produced viable parthenogenetic adults, but only D. mercatorum produced parthenogenetic females themselves capable of parthenogenesis. Moreover, D. mercatorum produced several "hot" lines characterized by high parthenogenetic rates, while all lines of D. hydei had a homogenous low rate. The parthenogenetic capacity of the cactus-patch D. mercatorum was lower than that of the garbage-dump D. mercatorum. Moreover, both the cactus-patch D. mercatorum and D. hydei had lower levels of polymorphism (26% and 22%, respectively) then the garbagedump D. mercatorum (44%), and both cactus-patch populations had heterozygote deficiencies with respect to Hardy-Weinberg equilibrium, unlike the garbage-dump population. Consequently, these data do not support the idea that decreased levels of heterozygosity in a sexual population increase the chance that sexual females will produce totally homozygous, parthenogenetic progeny. PMID:17248952

  5. Suppression of RNAi by dsRNA-degrading RNaseIII enzymes of viruses in animals and plants.

    Directory of Open Access Journals (Sweden)

    Isabel Weinheimer

    2015-03-01

    Full Text Available Certain RNA and DNA viruses that infect plants, insects, fish or poikilothermic animals encode Class 1 RNaseIII endoribonuclease-like proteins. dsRNA-specific endoribonuclease activity of the RNaseIII of rock bream iridovirus infecting fish and Sweet potato chlorotic stunt crinivirus (SPCSV infecting plants has been shown. Suppression of the host antiviral RNA interference (RNAi pathway has been documented with the RNaseIII of SPCSV and Heliothis virescens ascovirus infecting insects. Suppression of RNAi by the viral RNaseIIIs in non-host organisms of different kingdoms is not known. Here we expressed PPR3, the RNaseIII of Pike-perch iridovirus, in the non-hosts Nicotiana benthamiana (plant and Caenorhabditis elegans (nematode and found that it cleaves double-stranded small interfering RNA (ds-siRNA molecules that are pivotal in the host RNA interference (RNAi pathway and thereby suppresses RNAi in non-host tissues. In N. benthamiana, PPR3 enhanced accumulation of Tobacco rattle tobravirus RNA1 replicon lacking the 16K RNAi suppressor. Furthermore, PPR3 suppressed single-stranded RNA (ssRNA--mediated RNAi and rescued replication of Flock House virus RNA1 replicon lacking the B2 RNAi suppressor in C. elegans. Suppression of RNAi was debilitated with the catalytically compromised mutant PPR3-Ala. However, the RNaseIII (CSR3 produced by SPCSV, which cleaves ds-siRNA and counteracts antiviral RNAi in plants, failed to suppress ssRNA-mediated RNAi in C. elegans. In leaves of N. benthamiana, PPR3 suppressed RNAi induced by ssRNA and dsRNA and reversed silencing; CSR3, however, suppressed only RNAi induced by ssRNA and was unable to reverse silencing. Neither PPR3 nor CSR3 suppressed antisense-mediated RNAi in Drosophila melanogaster. These results show that the RNaseIII enzymes of RNA and DNA viruses suppress RNAi, which requires catalytic activities of RNaseIII. In contrast to other viral silencing suppression proteins, the RNaseIII enzymes are

  6. Higher dopamine level enhances male-male courtship in Drosophila

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ On May 21 2008, Journal of Neuroscience published an online paper from the Institute of Neuroscience, the CAS Shanghai Institutes for Biological Sciences, entitled "Increased dopamine level enhances male-male courtship in Drosophila." This work was done by Mr. LIU Tong, a doctoral candidate, and colleagues under the supervision of Dr. GUO Aike, and in collaboration with Dr. Jean-Francois Ferveur from France.

  7. Further studies of the engrailed phenotype in Drosophila.

    OpenAIRE

    Lawrence, P. A.; Struhl, G

    1982-01-01

    Although most mutations at the engrailed locus of Drosophila cause embryonic death when homozygous, they are viable in clones of cells. We describe the phenotype of such clones in the eye-antenna, proboscis, humerus, wing, legs, and terminalia. When in anterior compartments the clones are normal, but in most posterior compartments they are abnormal and fail to respect the anteroposterior compartment boundary. We find that the yield of engrailed-lethal clones in posterior compartments is often...

  8. Organically Grown Food Provides Health Benefits to Drosophila melanogaster

    OpenAIRE

    Chhabra, Ria; Kolli, Santharam; Bauer, Johannes H.

    2013-01-01

    The “organic food” market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on a diets consisting of extracts of either conventionally or organically raised produce (bananas...

  9. Genetic approaches to study aging in Drosophila melanogaster

    OpenAIRE

    Poirier, Luc; Seroude, Laurent

    2005-01-01

    The process of aging can be described as a progressive decline in an organism's function that invariably results in death. This decline results from the activities of intrinsic genetic factors within an organism. The relative contributions of the biological and environmental components to senescence are hard to measure, however different strategies have been devised in Drosophila melanogaster to isolate and identify genetic influences on aging. These strategies include selective breeding, qua...

  10. Targeting cyclin-dependent kinases in Drosophila with peptide aptamers

    OpenAIRE

    Kolonin, Mikhail G.; Finley, Russell L.

    1998-01-01

    Two-hybrid technology provides a simple way to isolate small peptide aptamers that specifically recognize and strongly bind to a protein of interest. These aptamers have the potential to dominantly interfere with specific activities of their target proteins and, therefore, could be used as in vivo inhibitors. Here we explore the ability to use peptide aptamers as in vivo inhibitors by expressing aptamers directed against cell cycle regulators in Drosophila. We expressed two peptide aptamers, ...

  11. Organically Grown Food Provides Health Benefits to Drosophila melanogaster

    OpenAIRE

    Ria Chhabra; Santharam Kolli; Bauer, Johannes H.

    2013-01-01

    The "organic food" market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on a diets consisting of extracts of either conventionally or organically raised produce (bananas...

  12. Layered reward signalling through octopamine and dopamine in Drosophila

    OpenAIRE

    Burke, Christopher J.; Huetteroth, Wolf; Owald, David; Perisse, Emmanuel; Krashes, Michael J.; Das, Gaurav; Gohl, Daryl; Silies, Marion; Certel, Sarah; Waddell, Scott

    2012-01-01

    Dopamine is synonymous with reward and motivation in mammals. However, only recently has dopamine been linked to motivated behaviour and rewarding reinforcement in fruitflies. Instead, octopamine has historically been considered to be the signal for reward in insects. Here we show, using temporal control of neural function in Drosophila, that only short-term appetitive memory is reinforced by octopamine. Moreover, octopamine-dependent memory formation requires signalling through dopamine neur...

  13. Drosophila comet assay: insights, uses, and future perspectives

    OpenAIRE

    Gaivão, Isabel; Sierra, L. María

    2014-01-01

    The comet assay, a very useful tool in genotoxicity and DNA repair testing, is being applied to Drosophila melanogaster since around 15 years ago, by several research groups. This organism is a valuable model for all kind of processes related to human health, including DNA damage response. The assay has been performed mainly in vivo using different larvae cell types (from brain, midgut, hemolymph, and imaginal disk), but also in vitro with the S2 cell line. Since its first application, it has...

  14. Migration of Drosophila intestinal stem cells across organ boundaries

    OpenAIRE

    Takashima, Shigeo; Paul, Manash; Aghajanian, Patrick; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2013-01-01

    All components of the Drosophila intestinal tract, including the endodermal midgut and ectodermal hindgut/Malpighian tubules, maintain populations of dividing stem cells. In the midgut and hindgut, these stem cells originate from within larger populations of intestinal progenitors that proliferate during the larval stage and form the adult intestine during metamorphosis. The origin of stem cells found in the excretory Malpighian tubules (‘renal stem cells’) has not been established. In this p...

  15. Intestinal stem cell function in Drosophila and Mice

    OpenAIRE

    Jiang, Huaqi; Edgar, Bruce A.

    2012-01-01

    Epithelial cells of the digestive tracts of most animals are short-lived, and are constantly replenished by the progeny of long-lived, resident intestinal stem cells. Proper regulation of intestinal stem cell maintenance, proliferation and differentiation is critical for maintaining gut homeostasis. Here we review recent genetic studies of stem cell-mediated homeostatic growth in the Drosophila midgut and the mouse small intestine, highlighting similarities and differences in the mechanisms t...

  16. Genetic Differentiation between Geographically Distant Populations of DROSOPHILA MELANOGASTER

    OpenAIRE

    Rama S Singh; Hickey, Donal A; David, Jean

    1982-01-01

    We have studied allozyme variation at 26 gene loci in nine populations of Drosophila melanogaster originating on five different continents. The distant populations show significant genetic differentiation. However, only half of the loci studied have contributed to this differentiation; the other half show identical patterns in all populations. The genetic differentiation in North American, European and African populations is correlated with the major climatic differences between north and sou...

  17. Notch signaling in Drosophila long-term memory formation

    OpenAIRE

    Ge, Xuecai; Hannan, Frances; Xie, Zuolei; Feng, Chunhua; Tully, Tim; Zhou, Haimeng; Xie, Zuoping; Zhong, Yi

    2004-01-01

    Notch (N) is a cell surface receptor that mediates an evolutionarily ancient signaling pathway to control an extraordinarily broad spectrum of cell fates and developmental processes. To gain insights into the functions of N signaling in the adult brain, we examined the involvement of N in Drosophila olfactory learning and memory. Long-term memory (LTM) was disrupted by blocking N signaling in conditional mutants or by acutely induced expression of a dominant-negative N transgene. In contrast,...

  18. Fungal diversity associated with Hawaiian Drosophila host plants.

    Directory of Open Access Journals (Sweden)

    Brian S Ort

    Full Text Available Hawaiian Drosophila depend primarily, sometimes exclusively, on specific host plants for oviposition and larval development, and most specialize further on a particular decomposing part of that plant. Differences in fungal community between host plants and substrate types may establish the basis for host specificity in Hawaiian Drosophila. Fungi mediate decomposition, releasing plant micronutrients and volatiles that can indicate high quality substrates and serve as cues to stimulate oviposition. This study addresses major gaps in our knowledge by providing the first culture-free, DNA-based survey of fungal diversity associated with four ecologically important tree genera in the Hawaiian Islands. Three genera, Cheirodendron, Clermontia, and Pisonia, are important host plants for Drosophila. The fourth, Acacia, is not an important drosophilid host but is a dominant forest tree. We sampled fresh and rotting leaves from all four taxa, plus rotting stems from Clermontia and Pisonia. Based on sequences from the D1/D2 domain of the 26S rDNA gene, we identified by BLAST search representatives from 113 genera in 13 fungal classes. A total of 160 operational taxonomic units, defined on the basis of ≥97% genetic similarity, were identified in these samples, but sampling curves show this is an underestimate of the total fungal diversity present on these substrates. Shannon diversity indices ranged from 2.0 to 3.5 among the Hawaiian samples, a slight reduction compared to continental surveys. We detected very little sharing of fungal taxa among the substrates, and tests of community composition confirmed that the structure of the fungal community differed significantly among the substrates and host plants. Based on these results, we hypothesize that fungal community structure plays a central role in the establishment of host preference in the Hawaiian Drosophila radiation.

  19. Extremes of Lineage Plasticity in the Drosophila Brain

    OpenAIRE

    Lin, Suewei; Marin, Elizabeth C.; Yang, Ching-Po; Kao, Chih-Fei; Apenteng, Bettye A.; Huang, Yaling; O’Connor, Michael B.; Truman, James W.; Lee, Tzumin

    2013-01-01

    An often-overlooked aspect of neural plasticity is the plasticity of neuronal composition, in which the numbers of neurons of particular classes are altered in response to environment and experience. The Drosophila brain features several well-characterized lineages in which a single neuroblast gives rise to multiple neuronal classes in a stereotyped sequence during development [1]. We find that in the intrinsic mushroom body neuron lineage, the numbers for each class are highly plastic, depen...

  20. Distinct types of glial cells populate the Drosophila antenna

    Directory of Open Access Journals (Sweden)

    Jhaveri Dhanisha

    2005-11-01

    Full Text Available Abstract Background The development of nervous systems involves reciprocal interactions between neurons and glia. In the Drosophila olfactory system, peripheral glial cells arise from sensory lineages specified by the basic helix-loop-helix transcription factor, Atonal. These glia wrap around the developing olfactory axons early during development and pattern the three distinct fascicles as they exit the antenna. In the moth Manduca sexta, an additional set of central glia migrate to the base of the antennal nerve where axons sort to their glomerular targets. In this work, we have investigated whether similar types of cells exist in the Drosophila antenna. Results We have used different P(Gal4 lines to drive Green Fluorescent Protein (GFP in distinct populations of cells within the Drosophila antenna. Mz317::GFP, a marker for cell body and perineural glia, labels the majority of peripheral glia. An additional ~30 glial cells detected by GH146::GFP do not derive from any of the sensory lineages and appear to migrate into the antenna from the brain. Their appearance in the third antennal segment is regulated by normal function of the Epidermal Growth Factor receptor and small GTPases. We denote these distinct populations of cells as Mz317-glia and GH146-glia respectively. In the adult, processes of GH146-glial cells ensheath the olfactory receptor neurons directly, while those of the Mz317-glia form a peripheral layer. Ablation of GH146-glia does not result in any significant effects on the patterning of the olfactory receptor axons. Conclusion We have demonstrated the presence of at least two distinct populations of glial cells within the Drosophila antenna. GH146-glial cells originate in the brain and migrate to the antenna along the newly formed olfactory axons. The number of cells populating the third segment of the antenna is regulated by signaling through the Epidermal Growth Factor receptor. These glia share several features of the sorting

  1. Minocycline Effect on Life and Health Span of Drosophila Melanogaster

    OpenAIRE

    Oxenkrug, Gregory; Navrotskaya, Valeriya; Vorobyova, Lyudmila; Summergrad, Paul

    2012-01-01

    Up-regulation of kynurenine (KYN) pathway of tryptophan (TRP) was suggested as one of the mechanisms of aging and aging-associated disorders. Genetic and pharmacological impairment of TRP – KYN metabolism resulted in prolongation of life span in Drosophila models. Minocycline, an antibiotic with anti-inflammatory, antioxidant and neuroprotective properties independent of its antibacterial activity, inhibited KYN formation from TRP. Since minocycline is the only FDA approved for human use medi...

  2. Maintaining the Brain: Insight into Human Neurodegeneration From Drosophila Mutants

    OpenAIRE

    Lessing, Derek; Bonini, Nancy M.

    2009-01-01

    The fruit fly Drosophila melanogaster has brought significant advances to research in neurodegenerative disease, notably in the identification of genes that are required to maintain the structural integrity of the brain, defined by recessive mutations that cause adult-onset neurodegeneration. Here, we survey these genes in the fly and classify them according to five key cell biological processes. Over half of these genes have counterparts in mouse or human that are also associated with neurod...

  3. Transcriptional control of stem cell maintenance in the Drosophila intestine

    OpenAIRE

    Bardin, Allison J.; Perdigoto, Carolina N.; Southall, Tony D.; Brand, Andrea H; Schweisguth, François

    2010-01-01

    Adult stem cells maintain tissue homeostasis by controlling the proper balance of stem cell self-renewal and differentiation. The adult midgut of Drosophila contains multipotent intestinal stem cells (ISCs) that self-renew and produce differentiated progeny. Control of ISC identity and maintenance is poorly understood. Here we find that transcriptional repression of Notch target genes by a Hairless-Suppressor of Hairless complex is required for ISC maintenance, and identify genes of the Enhan...

  4. Physiological homology between Drosophila melanogaster and vertebrate cardiovascular systems

    OpenAIRE

    Choma, Michael A.; Suter, Melissa J.; Vakoc, Benjamin J.; Bouma, Brett E; Tearney, Guillermo J.

    2010-01-01

    SUMMARY The physiology of the Drosophila melanogaster cardiovascular system remains poorly characterized compared with its vertebrate counterparts. Basic measures of physiological performance remain unknown. It also is unclear whether subtle physiological defects observed in the human cardiovascular system can be reproduced in D. melanogaster. Here we characterize the cardiovascular physiology of D. melanogaster in its pre-pupal stage by using high-speed dye angiography and optical coherence ...

  5. Sexual experience affects ethanol intake in Drosophila through Neuropeptide F

    OpenAIRE

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

    2012-01-01

    The brain's reward systems evolved to 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 use Drosophila melanogaster to investigate the relationship between natural and drug rewards. In males, mating increased Neuropeptide F (NPF) levels, whereas sexual deprivation reduced NPF. Activation or inhibition of the NPF system in turn enhanced or reduced ethanol...

  6. Drosophila melanogaster as a Model Organism of Brain Diseases

    OpenAIRE

    Werner Paulus; Astrid Jeibmann

    2009-01-01

    Drosophila melanogaster has been utilized to model human brain diseases. In most of these invertebrate transgenic models, some aspects of human disease are reproduced. Although investigation of rodent models has been of significant impact, invertebrate models offer a wide variety of experimental tools that can potentially address some of the outstanding questions underlying neurological disease. This review considers what has been gleaned from invertebrate models of neurodegenerative diseases...

  7. Morphometric analysis of Huntington's disease neurodegeneration in Drosophila

    OpenAIRE

    Song, W.; Smith Dell; Syed, A.; Lukacsovich, T; Barbaro, BA; Purcell, J.; Bornemann, DJ; J. Burke; Marsh, JL

    2013-01-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder. The HD gene encodes the huntingtin protein (HTT) that contains polyglutamine tracts of variable length. Expansions of the CAG repeat near the amino terminus to encode 40 or more glutamines (polyQ) lead to disease. At least eight other expanded polyQ diseases have been described [1]. HD can be faithfully modeled in Drosophila with the key features of the disease such as late onset, slowly progressing degeneration, f...

  8. Three-dimensional network of Drosophila brain hemisphere

    OpenAIRE

    Mizutani, Ryuta; Saiga, Rino; Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2016-01-01

    The first step to understanding brain function is to determine the brain's network structure. We report a three-dimensional analysis of the brain network of the fruit fly Drosophila melanogaster by synchrotron-radiation tomographic microscopy. A skeletonized wire model of the left half of the brain network was built by tracing the three-dimensional distribution of X-ray absorption coefficients. The obtained models of neuronal processes were classified into groups on the basis of their three-d...

  9. Growing Pains: Development of the Larval Nocifensive Response in Drosophila

    OpenAIRE

    Sulkowski, Mikolaj J.; Kurosawa, Mathieu S.; OX, DANIEL N.

    2011-01-01

    The ability to perceive and avoid harmful substances or stimuli is key to an organism’s survival. The neuronal cognate of the perception of pain is known as nociception, and the reflexive motion to avoid pain is termed the nocifensive response. As the nocifensive response is an ancient and evolutionarily conserved behavioral response to nociceptive stimuli, it is amenable to study in relatively simple and genetically tractable model systems such as Drosophila. Recent studies have taken advant...

  10. Prostaglandins temporally regulate cytoplasmic actin bundle formation during Drosophila oogenesis

    OpenAIRE

    Spracklen, Andrew J.; Kelpsch, Daniel J.; Chen, Xiang; Spracklen, Cassandra N.; Tootle, Tina L.

    2014-01-01

    Prostaglandins (PGs)—lipid signals produced downstream of cyclooxygenase (COX) enzymes—regulate actin dynamics in cell culture and platelets, but their roles during development are largely unknown. Here we define a new role for Pxt, the Drosophila COX-like enzyme, in regulating the actin cytoskeleton—temporal restriction of actin remodeling during oogenesis. PGs are required for actin filament bundle formation during stage 10B (S10B). In addition, loss of Pxt results in extensive early actin ...

  11. Odour avoidance learning in the larva of Drosophila melanogaster

    Indian Academy of Sciences (India)

    Sukant Khurana; Mohammed Bin AbuBaker; Obaid Siddiqi

    2009-10-01

    Drosophila larvae can be trained to avoid odours associated with electric shock. We describe here, an improved method of aversive conditioning and a procedure for decomposing learning retention curve that enables us to do a quantitative analysis of memory phases, short term (STM), middle term (MTM) and long term (LTM) as a function of training cycles. The same method of analysis when applied to learning mutants dunce, amnesiac, rutabaga and radish reveals memory deficits characteristic of the mutant strains.

  12. Drosophila melanogaster as a model for basal body research

    OpenAIRE

    Jana, Swadhin Chandra; Bettencourt-Dias, Mónica; Durand, Bénédicte; Timothy L. Megraw

    2016-01-01

    The fruit fly, Drosophila melanogaster, is one of the most extensively studied organisms in biological research and has centrioles/basal bodies and cilia that can be modelled to investigate their functions in animals generally. Centrioles are nine-fold symmetrical microtubule-based cylindrical structures required to form centrosomes and also to nucleate the formation of cilia and flagella. When they function to template cilia, centrioles transition into basal bodies. The fruit fly has various...

  13. P Transposable Elements in Drosophila and other Eukaryotic Organisms.

    Science.gov (United States)

    Majumdar, Sharmistha; Rio, Donald C

    2015-04-01

    P transposable elements were discovered in Drosophila as the causative agents of a syndrome of genetic traits called hybrid dysgenesis. Hybrid dysgenesis exhibits a unique pattern of maternal inheritance linked to the germline-specific small RNA piwi-interacting (piRNA) pathway. The use of P transposable elements as vectors for gene transfer and as genetic tools revolutionized the field of Drosophila molecular genetics. P element transposons have served as a useful model to investigate mechanisms of cut-and-paste transposition in eukaryotes. Biochemical studies have revealed new and unexpected insights into how eukaryotic DNA-based transposons are mobilized. For example, the P element transposase makes unusual 17nt-3' extended double-strand DNA breaks at the transposon termini and uses guanosine triphosphate (GTP) as a cofactor to promote synapsis of the two transposon ends early in the transposition pathway. The N-terminal DNA binding domain of the P element transposase, called a THAP domain, contains a C2CH zinc-coordinating motif and is the founding member of a large family of animal-specific site-specific DNA binding proteins. Over the past decade genome sequencing efforts have revealed the presence of P element-like transposable elements or P element transposase-like genes (called THAP9) in many eukaryotic genomes, including vertebrates, such as primates including humans, zebrafish and Xenopus, as well as the human parasite Trichomonas vaginalis, the sea squirt Ciona, sea urchin and hydra. Surprisingly, the human and zebrafish P element transposase-related THAP9 genes promote transposition of the Drosophila P element transposon DNA in human and Drosophila cells, indicating that the THAP9 genes encode active P element "transposase" proteins. PMID:26104714

  14. Heterogeneous Expression of Drosophila Gustatory Receptors in Enteroendocrine Cells

    OpenAIRE

    Jeong-Ho Park; Jae Young Kwon

    2011-01-01

    The gastrointestinal tract is emerging as a major site of chemosensation in mammalian studies. Enteroendocrine cells are chemosensory cells in the gut which produce regulatory peptides in response to luminal contents to regulate gut physiology, food intake, and glucose homeostasis, among other possible functions. Increasing evidence shows that mammalian taste receptors and taste signaling molecules are expressed in enteroendocrine cells in the gut. Invertebrate models such as Drosophila can p...

  15. Smelling, tasting, learning: Drosophila as a study case.

    Science.gov (United States)

    Gerber, B; Stocker, R F; Tanimura, T; Thum, A S

    2009-01-01

    Understanding brain function is to account for how the sensory system is integrated with the organism's needs to organize behaviour. We review what is known about these processes with regard to chemosensation and chemosensory learning in Drosophila. We stress that taste and olfaction are organized rather differently. Given that, e.g., sugars are nutrients and should be eaten (irrespective of the kind of sugar) and that toxic substances should be avoided (regardless of the kind of death they eventually cause), tastants are classified into relatively few behavioural matters of concern. In contrast, what needs to be done in response to odours is less evolutionarily determined. Thus, discrimination ability is warranted between different kinds of olfactory input, as any difference between odours may potentially be or become important. Therefore, the olfactory system has a higher dimensionality than gustation, and allows for more sensory-motor flexibility to attach acquired behavioural 'meaning' to odours. We argue that, by and large, larval and adult Drosophila are similar in these kinds of architecture, and that additionally there are a number of similarities to vertebrates, in particular regarding the cellular architecture of the olfactory pathway, the functional slant of the taste and smell systems towards classification versus discrimination, respectively, and the higher plasticity of the olfactory sensory-motor system. From our point of view, the greatest gap in understanding smell and taste systems to date is not on the sensory side, where indeed impressive advances have been achieved; also, a satisfying account of associative odour-taste memory trace formation seems within reach. Rather, we lack an understanding as to how sensory and motor formats of processing are centrally integrated, and how adaptive motor patterns actually are selected. Such an understanding, we believe, will allow the analysis to be extended to the motivating factors of behaviour, eventually

  16. Smelling, tasting, learning : Drosophila as a study case

    OpenAIRE

    Gerber, Bertram; Stocker, Reinhard F.; Tanimura, T.; Thum, Andreas

    2009-01-01

    Understanding brain function is to account for how the sensory system is integrated with the organism's needs to organize behaviour. We review what is known about these processes with regard to chemosensation and chemosensory learning in Drosophila. We stress that taste and olfaction are organized rather differently. Given that, e.g., sugars are nutrients and should be eaten (irrespective of the kind of sugar) and that toxic substances should be avoided (regardless of the kind of death they e...

  17. The aminoacyl-tRNA synthetases of Drosophila melanogaster

    OpenAIRE

    Lu, Jiongming; Marygold, Steven J; Gharib, Walid H; Suter, Beat

    2015-01-01

    Aminoacyl-tRNA synthetases (aaRSs) ligate amino acids to their cognate tRNAs, allowing them to decode the triplet code during translation. Through different mechanisms aaRSs also perform several non-canonical functions in transcription, translation, apoptosis, angiogenesis and inflammation. Drosophila has become a preferred system to model human diseases caused by mutations in aaRS, to dissect effects of reduced translation or non-canonical activities, and to study aminoacylation and translat...

  18. Recent advances in using Drosophila to model neurodegenerative diseases

    OpenAIRE

    Lu, Bingwei

    2009-01-01

    Neurodegenerative diseases are progressive disorders of the nervous system that affect the function and maintenance of specific neuronal populations. Most disease cases are sporadic with no known cause. The identification of genes associated with familial cases of these diseases has enabled the development of animal models to study disease mechanisms. The model organism Drosophila has been successfully used to study pathogenic mechanisms of a wide range of neurodegenerative diseases. Recent g...

  19. Metabolic effects of CO2 anaesthesia in Drosophila melanogaster

    OpenAIRE

    Colinet, H.; Renault, D.

    2012-01-01

    Immobilization of insects is necessary for various experimental purposes, and CO2 exposure remains the most popular anaesthetic method in entomological research. A number of negative side effects of CO2 anaesthesia have been reported, but CO2 probably brings about metabolic modifications that are poorly known. In this work, we used GC/MS-based metabolic fingerprinting to assess the effect of CO2 anaesthesia in Drosophila melanogaster adults. We analysed metabolic variation of flies submitted ...

  20. Drosophila lowfat, a novel modulator of Fat signaling

    OpenAIRE

    Mao, Yaopan; Kucuk, Binnaz; Irvine, Kenneth D.

    2009-01-01

    The Fat-Hippo-Warts signaling network regulates both transcription and planar cell polarity. Despite its crucial importance to the normal control of growth and planar polarity, we have only a limited understanding of the mechanisms that regulate Fat. We report here the identification of a conserved cytoplasmic protein, Lowfat (Lft), as a modulator of Fat signaling. Drosophila Lft, and its human homologs LIX1 and LIX1-like, bind to the cytoplasmic domains of the Fat lig...

  1. spenito is required for sex determination in Drosophila melanogaster

    OpenAIRE

    Yan, Dong; Perrimon, Norbert

    2015-01-01

    Sex determination is a fundamental biological problem faced by all metazoans. To understand the sex determination pathway, it is important to identify all the genes involved in this process. In this study, we have identified a novel gene, spenito (nito), which is required for sex determination in Drosophila melanogaster. Loss of nito function in the soma transforms female tissues to male, and loss of nito function in female germ-line stem cells changes their sexual identity and prevents them ...

  2. Cotranscriptional splicing efficiency differs dramatically between Drosophila and mouse

    OpenAIRE

    Khodor, Yevgenia L.; Menet, Jerome S; Tolan, Michael; Rosbash, Michael

    2012-01-01

    Spliceosome assembly and/or splicing of a nascent transcript may be crucial for proper isoform expression and gene regulation in higher eukaryotes. It has been shown that cotranscriptional splicing occurs efficiently in Drosophila, but there are not comparable genome-wide nascent splicing data from mammals. To provide this comparison, the authors analyzed a recently generated, high-throughput sequencing data set of mouse liver nascent RNA. Cotranscriptional splicing is approximately twofold l...

  3. Chaos suppression through asymmetric coupling

    Science.gov (United States)

    Bragard, J.; Vidal, G.; Mancini, H.; Mendoza, C.; Boccaletti, S.

    2007-12-01

    We study pairs of identical coupled chaotic oscillators. In particular, we have used Roessler (in the funnel and no funnel regimes), Lorenz, and four-dimensional chaotic Lotka-Volterra models. In all four of these cases, a pair of identical oscillators is asymmetrically coupled. The main result of the numerical simulations is that in all cases, specific values of coupling strength and asymmetry exist that render the two oscillators periodic and synchronized. The values of the coupling strength for which this phenomenon occurs is well below the previously known value for complete synchronization. We have found that this behavior exists for all the chaotic oscillators that we have used in the analysis. We postulate that this behavior is presumably generic to all chaotic oscillators. In order to complete the study, we have tested the robustness of this phenomenon of chaos suppression versus the addition of some Gaussian noise. We found that chaos suppression is robust for the addition of finite noise level. Finally, we propose some extension to this research.

  4. Antimutagenic Profile of Antioxidant Vitamins in Drosophila Mulation Test

    Institute of Scientific and Technical Information of China (English)

    P.K.KHAN; S.P.SINHA

    2008-01-01

    Objective To assess the antimutagenicity of antioxidant vitamins(vitamins A,C,and E)as expressed by their efficacy to of X-chromosome linked recessive lethal mutations(XRLMs)in Drosophila.Larvae were exposed to dietary concentration of aflatoxins and/or the human therapeutic doses of any ofthe three antioxidant vitamins. Absence of normal eyedmales among M2 progeny gave an indication of mutation induction. Results Aflatoxin supplimentation significantly increased the incidence of XRLMs in Drosophila.Mutation frequency was also raised a little above the control level in case of vitamin treatment.However,notable mitigation in mutation frequency was registered when aflatoxin-treated larvae were concomitantly fed with any of the three antioxidant vitamins.Conclusion Aflatoxin exposure can enhance the frequency of gene mutation in Drosophila which is significantly lowered by each of the three antioxidant vitamins.The degree of amelioration produced by them is almost identical.This mitigation is based on the scavenging/trapping by antioxidant vitamins of DNA-reactive products (metabolites and radicals)emanating from aflatoxin metabofism.

  5. Specialized Cortex Glial Cells Accumulate Lipid Droplets in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Viktor Kis

    Full Text Available Lipid droplets (LDs are common organelles of the majority of eukaryotic cell types. Their biological significance has been extensively studied in mammalian liver cells and white adipose tissue. Although the central nervous system contains the highest relative amount and the largest number of different lipid species, neither the spatial nor the temporal distribution of LDs has been described. In this study, we used the brain of the fruitfly, Drosophila melanogaster, to investigate the neuroanatomy of LDs. We demonstrated that LDs are exclusively localised in glial cells but not in neurons in the larval nervous system. We showed that the brain's LD pool, rather than being constant, changes dynamically during development and reaches its highest value at the beginning of metamorphosis. LDs are particularly enriched in cortex glial cells located close to the brain surface. These specialized superficial cortex glial cells contain the highest amount of LDs among glial cell types and encapsulate neuroblasts and their daughter cells. Superficial cortex glial cells, combined with subperineurial glial cells, express the Drosophila fatty acid binding protein (Dfabp, as we have demonstrated through light- and electron microscopic immunocytochemistry. To the best of our best knowledge this is the first study that describes LD neuroanatomy in the Drosophila larval brain.

  6. Dopamine modulates metabolic rate and temperature sensitivity in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Taro Ueno

    Full Text Available Homeothermal animals, such as mammals, maintain their body temperature by heat generation and heat dissipation, while poikilothermal animals, such as insects, accomplish it by relocating to an environment of their favored temperature. Catecholamines are known to regulate thermogenesis and metabolic rate in mammals, but their roles in other animals are poorly understood. The fruit fly, Drosophila melanogaster, has been used as a model system for the genetic studies of temperature preference behavior. Here, we demonstrate that metabolic rate and temperature sensitivity of some temperature sensitive behaviors are regulated by dopamine in Drosophila. Temperature-sensitive molecules like dTrpA1 and shi(ts induce temperature-dependent behavioral changes, and the temperature at which the changes are induced were lowered in the dopamine transporter-defective mutant, fumin. The mutant also displays a preference for lower temperatures. This thermophobic phenotype was rescued by the genetic recovery of the dopamine transporter in dopamine neurons. Flies fed with a dopamine biosynthesis inhibitor (3-iodo-L-tyrosine, which diminishes dopamine signaling, exhibited preference for a higher temperature. Furthermore, we found that the metabolic rate is up-regulated in the fumin mutant. Taken together, dopamine has functions in the temperature sensitivity of behavioral changes and metabolic rate regulation in Drosophila, as well as its previously reported functions in arousal/sleep regulation.

  7. Distinct Biochemical Activities of Eyes absent During Drosophila Eye Development.

    Science.gov (United States)

    Jin, Meng; Mardon, Graeme

    2016-01-01

    Eyes absent (Eya) is a highly conserved transcriptional coactivator and protein phosphatase that plays vital roles in multiple developmental processes from Drosophila to humans. Eya proteins contain a PST (Proline-Serine-Threonine)-rich transactivation domain, a threonine phosphatase motif (TPM), and a tyrosine protein phosphatase domain. Using a genomic rescue system, we find that the PST domain is essential for Eya activity and Dac expression, and the TPM is required for full Eya function. We also find that the threonine phosphatase activity plays only a minor role during Drosophila eye development and the primary function of the PST and TPM domains is transactivation that can be largely substituted by the heterologous activation domain VP16. Along with our previous results that the tyrosine phosphatase activity of Eya is dispensable for normal Eya function in eye formation, we demonstrate that a primary function of Eya during Drosophila eye development is as a transcriptional coactivator. Moreover, the PST/TPM and the threonine phosphatase activity are not required for in vitro interaction between retinal determination factors. Finally, this work is the first report of an Eya-Ey physical interaction. These findings are particularly important because they highlight the need for an in vivo approach that accurately dissects protein function. PMID:26980695

  8. A development-based compartmentalization of the Drosophila central brain

    Science.gov (United States)

    Pereanu, Wayne; Kumar, Abilasha; Jennett, Arnim; Reichert, Heinrich; Hartenstein, Volker

    2010-01-01

    The neuropile of the Drosophila brain is subdivided into anatomically discrete compartments. Compartments are rich in terminal neurite branching and synapses; they are the neuropile domains in which signal processing takes place. Compartment boundaries are defined by more or less dense layers of glial cells, as well as long neurite fascicles. These fascicles are formed during the larval period when the approximately 100 neuronal lineages that constitute the Drosophila central brain differentiate. Each lineage forms an axon tract with a characteristic trajectory in the neuropile; groups of spatially related tracts congregate into the brain fascicles that can be followed from the larva throughout metamorphosis into the adult stage. In this paper we provide a map of the adult brain compartments and the relevant fascicles defining compartmental boundaries. We have identified the neuronal lineages contributing to each fascicle, which allowed us to directly compare compartments of the larval and adult brain. Most adult compartments can be recognized already in the early larval brain where they form a “protomap” of the later adult compartments. Our analysis highlights the morphogenetic changes shaping the Drosophila brain; the data will be important for studies that link early acting genetic mechanisms to the adult neuronal structures and circuits controlled by these mechanisms. PMID:20533357

  9. Development-based compartmentalization of the Drosophila central brain.

    Science.gov (United States)

    Pereanu, Wayne; Kumar, Abilasha; Jennett, Arnim; Reichert, Heinrich; Hartenstein, Volker

    2010-08-01

    The neuropile of the Drosophila brain is subdivided into anatomically discrete compartments. Compartments are rich in terminal neurite branching and synapses; they are the neuropile domains in which signal processing takes place. Compartment boundaries are defined by more or less dense layers of glial cells as well as long neurite fascicles. These fascicles are formed during the larval period, when the approximately 100 neuronal lineages that constitute the Drosophila central brain differentiate. Each lineage forms an axon tract with a characteristic trajectory in the neuropile; groups of spatially related tracts congregate into the brain fascicles that can be followed from the larva throughout metamorphosis into the adult stage. Here we provide a map of the adult brain compartments and the relevant fascicles defining compartmental boundaries. We have identified the neuronal lineages contributing to each fascicle, which allowed us to compare compartments of the larval and adult brain directly. Most adult compartments can be recognized already in the early larval brain, where they form a "protomap" of the later adult compartments. Our analysis highlights the morphogenetic changes shaping the Drosophila brain; the data will be important for studies that link early-acting genetic mechanisms to the adult neuronal structures and circuits controlled by these mechanisms. PMID:20533357

  10. Modeling the complex pathology of Alzheimer's disease in Drosophila.

    Science.gov (United States)

    Fernandez-Funez, Pedro; de Mena, Lorena; Rincon-Limas, Diego E

    2015-12-01

    Alzheimer's disease (AD) is the leading cause of dementia and the most common neurodegenerative disorder. AD is mostly a sporadic disorder and its main risk factor is age, but mutations in three genes that promote the accumulation of the amyloid-β (Aβ42) peptide revealed the critical role of amyloid precursor protein (APP) processing in AD. Neurofibrillary tangles enriched in tau are the other pathological hallmark of AD, but the lack of causative tau mutations still puzzles researchers. Here, we describe the contribution of a powerful invertebrate model, the fruit fly Drosophila melanogaster, to uncover the function and pathogenesis of human APP, Aβ42, and tau. APP and tau participate in many complex cellular processes, although their main function is microtubule stabilization and the to-and-fro transport of axonal vesicles. Additionally, expression of secreted Aβ42 induces prominent neuronal death in Drosophila, a critical feature of AD, making this model a popular choice for identifying intrinsic and extrinsic factors mediating Aβ42 neurotoxicity. Overall, Drosophila has made significant contributions to better understand the complex pathology of AD, although additional insight can be expected from combining multiple transgenes, performing genome-wide loss-of-function screens, and testing anti-tau therapies alone or in combination with Aβ42. PMID:26024860

  11. Mechanisms and functions of Nrf2 signaling in Drosophila.

    Science.gov (United States)

    Pitoniak, Andrew; Bohmann, Dirk

    2015-11-01

    The Nrf2 transcription factor belongs to the Cap'n'collar family, named after the founding member of this group, the product of the Drosophila Cap'n'collar gene. The encoded protein, Cap'n'collar, abbreviated Cnc, offers a convenient and accessible model to study the structure, function, and biology of Nrf2 transcription factors at the organismic, tissular, cellular, and molecular levels, using the powerful genetic, genomic, and biochemical tools available in Drosophila. In this review we provide an account of the original identification of Cnc as a regulator of embryonic development. We then describe the discovery of Nrf2-like functions of Cnc and its role in acute stress signaling and aging. The establishment of Drosophila as a model organism in which the mechanisms and functions of Nrf2 signaling can be studied has led to several discoveries: the regulation of stem cell activity by an Nrf2-mediated redox mechanism, the interaction of Nrf2 with p62 and Myc in the control of tissue growth and the unfolded protein response, and more. Several of these more recent lines of investigation are highlighted. Model organisms such as the fly and the worm remain powerful experimental platforms that can help to unravel the many remaining puzzles regarding the role of Nrf2 and its relatives in controlling the physiology and maintaining the health of multicellular organisms. PMID:26117322

  12. A drosophila full-length cDNA resource

    Energy Technology Data Exchange (ETDEWEB)

    Stapleton, Mark; Carlson, Joseph; Brokstein, Peter; Yu, Charles; Champe, Mark; George, Reed; Guarin, Hannibal; Kronmiller, Brent; Pacleb, Joanne; Park, Soo; Rubin, Gerald M.; Celniker, Susan E.

    2003-05-09

    Background: A collection of sequenced full-length cDNAs is an important resource both for functional genomics studies and for the determination of the intron-exon structure of genes. Providing this resource to the Drosophila melanogaster research community has been a long-term goal of the Berkeley Drosophila Genome Project. We have previously described the Drosophila Gene Collection (DGC), a set of putative full-length cDNAs that was produced by generating and analyzing over 250,000 expressed sequence tags (ESTs) derived from a variety of tissues and developmental stages. Results: We have generated high-quality full-insert sequence for 8,921 clones in the DGC. We compared the sequence of these clones to the annotated Release 3 genomic sequence, and identified more than 5,300 cDNAs that contain a complete and accurate protein-coding sequence. This corresponds to at least one splice form for 40 percent of the predicted D. melanogaster genes. We also identified potential new cases of RNA editing. Conclusions: We show that comparison of cDNA sequences to a high-quality annotated genomic sequence is an effective approach to identifying and eliminating defective clones from a cDNA collection and ensure its utility for experimentation. Clones were eliminated either because they carry single nucleotide discrepancies, which most probably result from reverse transcriptase errors, or because they are truncated and contain only part of the protein-coding sequence.

  13. Distinct signaling of Drosophila chemoreceptors in olfactory sensory neurons.

    Science.gov (United States)

    Cao, Li-Hui; Jing, Bi-Yang; Yang, Dong; Zeng, Xiankun; Shen, Ying; Tu, Yuhai; Luo, Dong-Gen

    2016-02-16

    In Drosophila, olfactory sensory neurons (OSNs) rely primarily on two types of chemoreceptors, odorant receptors (Ors) and ionotropic receptors (Irs), to convert odor stimuli into neural activity. The cellular signaling of these receptors in their native OSNs remains unclear because of the difficulty of obtaining intracellular recordings from Drosophila OSNs. Here, we developed an antennal preparation that enabled the first recordings (to our knowledge) from targeted Drosophila OSNs through a patch-clamp technique. We found that brief odor pulses triggered graded inward receptor currents with distinct response kinetics and current-voltage relationships between Or- and Ir-driven responses. When stimulated with long-step odors, the receptor current of Ir-expressing OSNs did not adapt. In contrast, Or-expressing OSNs showed a strong Ca(2+)-dependent adaptation. The adaptation-induced changes in odor sensitivity obeyed the Weber-Fechner relation; however, surprisingly, the incremental sensitivity was reduced at low odor backgrounds but increased at high odor backgrounds. Our model for odor adaptation revealed two opposing effects of adaptation, desensitization and prevention of saturation, in dynamically adjusting odor sensitivity and extending the sensory operating range.

  14. Analysis of resistance and tolerance to virus infection in Drosophila.

    Science.gov (United States)

    Merkling, Sarah H; van Rij, Ronald P

    2015-07-01

    Host defense to virus infection involves both resistance mechanisms that reduce viral burden and tolerance mechanisms that limit detrimental effects of infection. The fruit fly, Drosophila melanogaster, has emerged as a model for identifying and characterizing the genetic basis of resistance and tolerance. This protocol describes how to analyze host responses to virus infection in Drosophila, and it covers the preparation of virus stocks, experimental inoculation of flies and assessment of host survival and virus production, which are indicative of resistance or tolerance. It also provides guidance on how to account for recently identified confounding factors, including natural genetic variation in the pastrel locus and contamination of fly stocks with persistent viruses and the symbiotic bacterium Wolbachia. Our protocol aims to be accessible to newcomers to the field and, although optimized for virus research using Drosophila, some of the techniques could be adapted to other host organisms and/or other microbial pathogens. Preparation of fly stocks requires ∼1 month, virus stock preparation requires 17-20 d, virus injection and survival assays require 10-15 d and virus titration requires 14 d.

  15. Tropics accelerate the evolution of hybrid male sterility in Drosophila.

    Science.gov (United States)

    Yukilevich, Roman

    2013-06-01

    Understanding the evolutionary mechanisms that facilitate speciation and explain global patterns of species diversity has remained a challenge for decades. The most general pattern of species biodiversity is the latitudinal gradient, whereby species richness increases toward the tropics. Although such a global pattern probably has a multitude of causes, recent attention has focused on the hypothesis that speciation and the evolution of reproductive isolation occur faster in the tropics. Here, I tested this prediction using a dataset on premating and postzygotic isolation between recently diverged Drosophila species. Results showed that while the evolution of premating isolation was not greater between tropical Drosophila relative to nontropical species, postzygotic isolation evolved faster in the tropics. In particular, hybrid male sterility was much greater among tropical Drosophila compared to nontropical species pairs of similar genetic age. Several testable explanations for the novel pattern are discussed, including greater role for sterility-inducing bacterial endosymbionts in the tropics and more intense sperm-sperm competition or sperm-egg sexual conflict in the tropics. The results imply that processes of speciation in the tropics may evolve at different rates or may even be somewhat different from those at higher latitudes.

  16. The ecdysteroidome of Drosophila: influence of diet and development.

    Science.gov (United States)

    Lavrynenko, Oksana; Rodenfels, Jonathan; Carvalho, Maria; Dye, Natalie A; Lafont, Rene; Eaton, Suzanne; Shevchenko, Andrej

    2015-11-01

    Ecdysteroids are the hormones regulating development, physiology and fertility in arthropods, which synthesize them exclusively from dietary sterols. But how dietary sterol diversity influences the ecdysteroid profile, how animals ensure the production of desired hormones and whether there are functional differences between different ecdysteroids produced in vivo remains unknown. This is because currently there is no analytical technology for unbiased, comprehensive and quantitative assessment of the full complement of endogenous ecdysteroids. We developed a new LC-MS/MS method to screen the entire chemical space of ecdysteroid-related structures and to quantify known and newly discovered hormones and their catabolites. We quantified the ecdysteroidome in Drosophila melanogaster and investigated how the ecdysteroid profile varies with diet and development. We show that Drosophila can produce four different classes of ecdysteroids, which are obligatorily derived from four types of dietary sterol precursors. Drosophila makes makisterone A from plant sterols and epi-makisterone A from ergosterol, the major yeast sterol. However, they prefer to selectively utilize scarce ergosterol precursors to make a novel hormone 24,28-dehydromakisterone A and trace cholesterol to synthesize 20-hydroxyecdysone. Interestingly, epi-makisterone A supports only larval development, whereas all other ecdysteroids allow full adult development. We suggest that evolutionary pressure against producing epi-C-24 ecdysteroids might explain selective utilization of ergosterol precursors and the puzzling preference for cholesterol.

  17. Transgenic Drosophila model to study apolipoprotein E4-induced neurodegeneration.

    Science.gov (United States)

    Haddadi, Mohammad; Nongthomba, Upendra; Jahromi, Samaneh Reiszadeh; Ramesh, S R

    2016-03-15

    The ε4 isoform of apolipoprotein E (ApoE4) that is involved in neuron-glial lipid metabolism has been demonstrated as the main genetic risk factor in late-onset of Alzheimer's disease. However, the mechanism underlying ApoE4-mediated neurodegeneration remains unclear. We created a transgenic model of neurodegenerative disorder by expressing ε3 and ε4 isoforms of human ApoE in the Drosophila melanogaster. The genetic models exhibited progressive neurodegeneration, shortened lifespan and memory impairment. Genetic interaction studies between amyloid precursor protein and ApoE in axon pathology of the disease revealed that over expression of hApoE in Appl-expressing neurons of Drosophila brain causes neurodegeneration. Moreover, acute oxidative damage in the hApoE transgenic flies triggered a neuroprotective response of hApoE3 while chronic induction of oxidative damage accelerated the rate of neurodegeneration. This Drosophila model may facilitate analysis of the molecular and cellular events implicated in hApoE4 neurotoxicity.

  18. Drosophila and experimental neurology in the post-genomic era.

    Science.gov (United States)

    Shulman, Joshua M

    2015-12-01

    For decades, the fruit fly, Drosophila melanogaster, has been among the premiere genetic model systems for probing fundamental neurobiology, including elucidation of mechanisms responsible for human neurologic disorders. Flies continue to offer virtually unparalleled versatility and speed for genetic manipulation, strong genomic conservation, and a nervous system that recapitulates a range of cellular and network properties relevant to human disease. I focus here on four critical challenges emerging from recent advances in our understanding of the genomic basis of human neurologic disorders where innovative experimental strategies are urgently needed: (1) pinpointing causal genes from associated genomic loci; (2) confirming the functional impact of allelic variants; (3) elucidating nervous system roles for novel or poorly studied genes; and (4) probing network interactions within implicated regulatory pathways. Drosophila genetic approaches are ideally suited to address each of these potential translational roadblocks, and will therefore contribute to mechanistic insights and potential breakthrough therapies for complex genetic disorders in the coming years. Strategic collaboration between neurologists, human geneticists, and the Drosophila research community holds great promise to accelerate progress in the post-genomic era.

  19. Heavy metals effect in Drosophila melanogaster germinal cells

    International Nuclear Information System (INIS)

    Heavy metals occur naturally and some of them are very important in cellular metabolism. Industrial development has increased metal concentration in the environment and in the living organisms tissues. This increase promotes the human risk to suffer teratogenesis, carcinogenesis and mutagenesis. Different biological systems have been used to proof the genetic effect of heavy metals including Drosophila. In the present work chromium, cadmium, lead, zinc and arsenic salts were administered to Drosophila females and males adults in order to determine the genetic effect produced by these compounds, in both femenine and masculine germinal cells. The mating system used (''Oster males'' and y2wsup(a)/y2wsup(a); e/e females) permited to determine among two succesive generations, the mutagenic effects produced by heavy metals in Drosophila. The salts administration to adult flies was made by injection. Non-disjunction, X-chromosome loss, and sex linked recessive lethals frequency was increased by heavy metals. It was observed a fertility disminution between F 1 descendants from individuals treated with the metalic salts. It was demonstrated that heavy metals can interact with genetic material at different levels in the two types of gametic cells to produce genetic damage. (author)

  20. Drosophila Adaptation to Viral Infection through Defensive Symbiont Evolution

    Science.gov (United States)

    Faria, Vitor G.; Magalhães, Sara; Paulo, Tânia F.; Nolte, Viola; Schlötterer, Christian

    2016-01-01

    Microbial symbionts can modulate host interactions with biotic and abiotic factors. Such interactions may affect the evolutionary trajectories of both host and symbiont. Wolbachia protects Drosophila melanogaster against several viral infections and the strength of the protection varies between variants of this endosymbiont. Since Wolbachia is maternally transmitted, its fitness depends on the fitness of its host. Therefore, Wolbachia populations may be under selection when Drosophila is subjected to viral infection. Here we show that in D. melanogaster populations selected for increased survival upon infection with Drosophila C virus there is a strong selection coefficient for specific Wolbachia variants, leading to their fixation. Flies carrying these selected Wolbachia variants have higher survival and fertility upon viral infection when compared to flies with the other variants. These findings demonstrate how the interaction of a host with pathogens shapes the genetic composition of symbiont populations. Furthermore, host adaptation can result from the evolution of its symbionts, with host and symbiont functioning as a single evolutionary unit. PMID:27684942

  1. Evaluation of polylactic acid nanoparticles safety using Drosophila model.

    Science.gov (United States)

    Legaz, Sophie; Exposito, Jean-Yves; Lethias, Claire; Viginier, Barbara; Terzian, Christophe; Verrier, Bernard

    2016-10-01

    Cytotoxicity of nanoparticles and their sub-lethal effect on cell behavior and cell fate are a high topic of studies in the nanomaterial field. With an explosion of nanoparticle types (size, shape, polarity, stiffness, composition, etc.), Drosophila has become an attractive animal model for high throughput analysis of these nanocarriers in the drug delivery field with applications in cancer therapy, or simply to generate a fast and complete cytotoxic study of a peculiar nanoparticle. In respect to that, we have conducted an in cellulo study of poly(lactic acid) (PLA) nanoparticle cytotoxicity, and determined that near lethal nanoparticle doses, oxidative stress as well as P53 and ATP pathways may lead to cell cycle arrest at G1, and ultimately to cell death. Neither viability nor the development of Drosophila larvae are affected by the ingestion of PLA nanoparticles at sub-lethal concentrations. Drosophila will be a useful model to study PLA and PLA-modified nanoparticle toxicity, and nanoparticle fate after ingestion. PMID:27108761

  2. Hawaiian Drosophila genomes: size variation and evolutionary expansions.

    Science.gov (United States)

    Craddock, Elysse M; Gall, Joseph G; Jonas, Mark

    2016-02-01

    This paper reports genome sizes of one Hawaiian Scaptomyza and 16 endemic Hawaiian Drosophila species that include five members of the antopocerus species group, one member of the modified mouthpart group, and ten members of the picture wing clade. Genome size expansions have occurred independently multiple times among Hawaiian Drosophila lineages, and have resulted in an over 2.3-fold range of genome sizes among species, with the largest observed in Drosophila cyrtoloma (1C = 0.41 pg). We find evidence that these repeated genome size expansions were likely driven by the addition of significant amounts of heterochromatin and satellite DNA. For example, our data reveal that the addition of seven heterochromatic chromosome arms to the ancestral haploid karyotype, and a remarkable proportion of ~70 % satellite DNA, account for the greatly expanded size of the D. cyrtoloma genome. Moreover, the genomes of 13/17 Hawaiian picture wing species are composed of substantial proportions (22-70 %) of detectable satellites (all but one of which are AT-rich). Our results suggest that in this tightly knit group of recently evolved species, genomes have expanded, in large part, via evolutionary amplifications of satellite DNA sequences in centric and pericentric domains (especially of the X and dot chromosomes), which have resulted in longer acrocentric chromosomes or metacentrics with an added heterochromatic chromosome arm. We discuss possible evolutionary mechanisms that may have shaped these patterns, including rapid fixation of novel expanded genomes during founder-effect speciation.

  3. Interactions among Drosophila larvae before and during collision.

    Science.gov (United States)

    Otto, Nils; Risse, Benjamin; Berh, Dimitri; Bittern, Jonas; Jiang, Xiaoyi; Klämbt, Christian

    2016-01-01

    In populations of Drosophila larvae, both, an aggregation and a dispersal behavior can be observed. However, the mechanisms coordinating larval locomotion in respect to other animals, especially in close proximity and during/after physical contacts are currently only little understood. Here we test whether relevant information is perceived before or during larva-larva contacts, analyze its influence on behavior and ask whether larvae avoid or pursue collisions. Employing frustrated total internal reflection-based imaging (FIM) we first found that larvae visually detect other moving larvae in a narrow perceptive field and respond with characteristic escape reactions. To decipher larval locomotion not only before but also during the collision we utilized a two color FIM approach (FIM(2c)), which allowed to faithfully extract the posture and motion of colliding animals. We show that during collision, larval locomotion freezes and sensory information is sampled during a KISS phase (german: Kollisions Induziertes Stopp Syndrom or english: collision induced stop syndrome). Interestingly, larvae react differently to living, dead or artificial larvae, discriminate other Drosophila species and have an increased bending probability for a short period after the collision terminates. Thus, Drosophila larvae evolved means to specify behaviors in response to other larvae.

  4. Heterogeneous expression of Drosophila gustatory receptors in enteroendocrine cells.

    Science.gov (United States)

    Park, Jeong-Ho; Kwon, Jae Young

    2011-01-01

    The gastrointestinal tract is emerging as a major site of chemosensation in mammalian studies. Enteroendocrine cells are chemosensory cells in the gut which produce regulatory peptides in response to luminal contents to regulate gut physiology, food intake, and glucose homeostasis, among other possible functions. Increasing evidence shows that mammalian taste receptors and taste signaling molecules are expressed in enteroendocrine cells in the gut. Invertebrate models such as Drosophila can provide a simple and genetically tractable system to study the chemosensory functions of enteroendocrine cells in vivo. To establish Drosophila enteroendocrine cells as a model for studying gut chemosensation, we used the GAL4/UAS system to examine the expression of all 68 Gustatory receptors (Grs) in the intestine. We find that 12 Gr-GAL4 drivers label subsets of enteroendocrine cells in the midgut, and examine colocalization of these drivers with the regulatory peptides neuropeptide F (NPF), locustatachykinin (LTK), and diuretic hormone 31 (DH31). RT-PCR analysis provides additional evidence for the presence of Gr transcripts in the gut. Our results suggest that the Drosophila Grs have chemosensory roles in the intestine to regulate physiological functions such as food uptake, nutrient absorption, or sugar homeostasis. PMID:22194978

  5. Heterogeneous expression of Drosophila gustatory receptors in enteroendocrine cells.

    Directory of Open Access Journals (Sweden)

    Jeong-Ho Park

    Full Text Available The gastrointestinal tract is emerging as a major site of chemosensation in mammalian studies. Enteroendocrine cells are chemosensory cells in the gut which produce regulatory peptides in response to luminal contents to regulate gut physiology, food intake, and glucose homeostasis, among other possible functions. Increasing evidence shows that mammalian taste receptors and taste signaling molecules are expressed in enteroendocrine cells in the gut. Invertebrate models such as Drosophila can provide a simple and genetically tractable system to study the chemosensory functions of enteroendocrine cells in vivo. To establish Drosophila enteroendocrine cells as a model for studying gut chemosensation, we used the GAL4/UAS system to examine the expression of all 68 Gustatory receptors (Grs in the intestine. We find that 12 Gr-GAL4 drivers label subsets of enteroendocrine cells in the midgut, and examine colocalization of these drivers with the regulatory peptides neuropeptide F (NPF, locustatachykinin (LTK, and diuretic hormone 31 (DH31. RT-PCR analysis provides additional evidence for the presence of Gr transcripts in the gut. Our results suggest that the Drosophila Grs have chemosensory roles in the intestine to regulate physiological functions such as food uptake, nutrient absorption, or sugar homeostasis.

  6. Status of research on Drosophila ananassae at global level

    Indian Academy of Sciences (India)

    B. N. Singh; J. P. Yadav

    2015-12-01

    Drosophila, a dipteran insect, has been found to be the best biological model for different kinds of studies. D. melanogaster was first described by Meigen in 1830, is most extensively studied species of the genus Drosophila and a number of investigations employing this species have been documented in areas such as genetics, behaviour, evolution, development, molecular biology, ecology, population biology, etc. Besides D. melanogaster, a number of other species of the genus Drosophila have also been used for different kinds of investigations. Among these, D. ananassae, a cosmopolitan and domestic species endowed with several unusual genetic features, is noteworthy. Described for the first time from Indonesia (Doleschall 1858), this species is commonly distributed in India. Extensive research work on D. ananassae has been done by numerous researchers pertaining to cytology, genetics, mutagenesis, gene mapping, crossing-over in both sexes, population and evolutionary genetics, behaviour genetics, ecological genetics, sexual isolation, fluctuating asymmetry, trade-offs etc. Genome of D. ananassae has also been sequenced. The status of research on D. ananassae at global level is briefly described in this review. Bibliography on this species from different countries worldwide reveals that maximum contribution is from India.

  7. Evaluation of polylactic acid nanoparticles safety using Drosophila model.

    Science.gov (United States)

    Legaz, Sophie; Exposito, Jean-Yves; Lethias, Claire; Viginier, Barbara; Terzian, Christophe; Verrier, Bernard

    2016-10-01

    Cytotoxicity of nanoparticles and their sub-lethal effect on cell behavior and cell fate are a high topic of studies in the nanomaterial field. With an explosion of nanoparticle types (size, shape, polarity, stiffness, composition, etc.), Drosophila has become an attractive animal model for high throughput analysis of these nanocarriers in the drug delivery field with applications in cancer therapy, or simply to generate a fast and complete cytotoxic study of a peculiar nanoparticle. In respect to that, we have conducted an in cellulo study of poly(lactic acid) (PLA) nanoparticle cytotoxicity, and determined that near lethal nanoparticle doses, oxidative stress as well as P53 and ATP pathways may lead to cell cycle arrest at G1, and ultimately to cell death. Neither viability nor the development of Drosophila larvae are affected by the ingestion of PLA nanoparticles at sub-lethal concentrations. Drosophila will be a useful model to study PLA and PLA-modified nanoparticle toxicity, and nanoparticle fate after ingestion.

  8. Drosophila cuticular hydrocarbons revisited: mating status alters cuticular profiles.

    Directory of Open Access Journals (Sweden)

    Claude Everaerts

    Full Text Available Most living organisms use pheromones for inter-individual communication. In Drosophila melanogaster flies, several pheromones perceived either by contact/at a short distance (cuticular hydrocarbons, CHs, or at a longer distance (cis-vaccenyl acetate, cVA, affect courtship and mating behaviours. However, it has not previously been possible to precisely identify all potential pheromonal compounds and simultaneously monitor their variation on a time scale. To overcome this limitation, we combined Solid Phase Micro-Extraction with gas-chromatography coupled with mass-spectrometry. This allowed us (i to identify 59 cuticular compounds, including 17 new CHs; (ii to precisely quantify the amount of each compound that could be detected by another fly, and (iii to measure the variation of these substances as a function of aging and mating. Sex-specific variation appeared with age, while mating affected cuticular compounds in both sexes with three possible patterns: variation was (i reciprocal in the two sexes, suggesting a passive mechanical transfer during mating, (ii parallel in both sexes, such as for cVA which strikingly appeared during mating, or (iii unilateral, presumably as a result of sexual interaction. We provide a complete reassessment of all Drosophila CHs and suggest that the chemical conversation between male and female flies is far more complex than is generally accepted. We conclude that focusing on individual compounds will not provide a satisfactory understanding of the evolution and function of chemical communication in Drosophila.

  9. Reproductive character displacement of epicuticular compounds and their contribution to mate choice in Drosophila subquinaria and Drosophila recens.

    Science.gov (United States)

    Dyer, Kelly A; White, Brooke E; Sztepanacz, Jacqueline L; Bewick, Emily R; Rundle, Howard D

    2014-04-01

    Interactions between species can alter selection on sexual displays used in mate choice within species. Here we study the epicuticular pheromones of two Drosophila species that overlap partially in geographic range and are incompletely reproductively isolated. Drosophila subquinaria shows a pattern of reproductive character displacement against Drosophila recens, and partial behavioral isolation between conspecific sympatric versus allopatric populations, whereas D. recens shows no such variation in mate choice. First, using manipulative perfuming experiments, we show that females use pheromones as signals for mate discrimination both between species and among populations of D. subquinaria. Second, we show that patterns of variation in epicuticular compounds, both across populations and between species, are consistent with those previously shown for mating probabilities: pheromone compositions differ between populations of D. subquinaria that are allopatric versus sympatric with D. recens, but are similar across populations of D. recens regardless of overlap with D. subquinaria. We also identify differences in pheromone composition among allopatric regions of D. subquinaria. In sum, our results suggest that epicuticular compounds are key signals used by females during mate recognition, and that these traits have diverged among D. subquinaria populations in response to reinforcing selection generated by the presence of D. recens.

  10. Field Evaluation of an Oviposition Deterrent for Management of Spotted-Wing Drosophila, Drosophila suzukii, and Potential Nontarget Effects.

    Science.gov (United States)

    Wallingford, Anna K; Connelly, Heather L; Dore Brind'Amour, Gabrielle; Boucher, Matthew T; Mafra-Neto, Agenor; Loeb, Greg M

    2016-08-01

    Spotted-wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), is a polyphagous, invasive pest of small fruits. Current management relies heavily on chemical insecticides, and an effective oviposition deterrent could contribute to alternative management approaches that reduce the need for these chemical insecticides. A novel deployment method for repelling Drosophila suzukii, thereby reducing D. suzukii oviposition in fall-bearing red raspberry, was evaluated in the field. Infestations occurring within 4 d after deployment were significantly lower in 2-m-long plots (Rubus idaeus 'Caroline') treated with the repellent (20% 1-octen-3-ol in specialized pheromone and lure application technology [SPLAT]) compared to control plots (blank SPLAT). Repellent-treated plots had roughly 28.8 and 49.5% fewer offspring reared per gram of fruit than control plots in two experiments, respectively. Nontarget effects were also evaluated in 2-m plot experiments as well as 5- by 5-m plot experiments. There were no differences in the number of parasitic hymenoptera trapped on yellow sticky cards hung in repellent compared to control plots. While there were no differences in the number of visits to raspberry flowers observed by honey bees in repellent versus control plots, the number of visits by bumble bees was greater in repellent plots compared to control plots. Challenges regarding evaporation rates and potential uses for repellents in an integrated pest management program for the control of D. suzukii are discussed. PMID:27247303

  11. Glycerol hypersensitivity in a Drosophila model for glycerol kinase deficiency is affected by mutations in eye pigmentation genes.

    Directory of Open Access Journals (Sweden)

    Patrick J Wightman

    Full Text Available Glycerol kinase plays a critical role in metabolism by converting glycerol to glycerol 3-phosphate in an ATP dependent reaction. In humans, glycerol kinase deficiency results in a wide range of phenotypic variability; patients can have severe metabolic and CNS abnormalities, while others possess hyperglycerolemia and glyceroluria with no other apparent phenotype. In an effort to help understand the pathogenic mechanisms underlying the phenotypic variation, we have created a Drosophila model for glycerol kinase deficiency by RNAi targeting of dGyk (CG18374 and dGK (CG7995. As expected, RNAi flies have reduced glycerol kinase RNA expression, reduced phosphorylation activity and elevated glycerol levels. Further investigation revealed these flies to be hypersensitive to fly food supplemented with glycerol. Due to the hygroscopic nature of glycerol, we predict glycerol hypersensitivity is a result of greater susceptibility to desiccation, suggesting glycerol kinase to play an important role in desiccation resistance in insects. To evaluate a role for genetic modifier loci in determining severity of the glycerol hypersensitivity observed in knockdown flies, we performed a preliminary screen of lethal transposon insertion mutant flies using a glycerol hypersensitive survivorship assay. We demonstrate that this type of screen can identify both enhancer and suppressor genetic loci of glycerol hypersensitivity. Furthermore, we found that the glycerol hypersensitivity phenotype can be enhanced or suppressed by null mutations in eye pigmentation genes. Taken together, our data suggest proteins encoded by eye pigmentation genes play an important role in desiccation resistance and that eye pigmentation genes are strong modifiers of the glycerol hypersensitive phenotype identified in our Drosophila model for glycerol kinase deficiency.

  12. The Drosophila gene CG9918 codes for a pyrokinin-1 receptor

    DEFF Research Database (Denmark)

    Cazzamali, Giuseppe; Torp, Malene; Hauser, Frank;

    2005-01-01

    The database from the Drosophila Genome Project contains a gene, CG9918, annotated to code for a G protein-coupled receptor. We cloned the cDNA of this gene and functionally expressed it in Chinese hamster ovary cells. We tested a library of about 25 Drosophila and other insect neuropeptides, and...

  13. Genome Engineering of Drosophila with the CRISPR RNA-Guided Cas9 Nuclease

    OpenAIRE

    Gratz, Scott J.; Cummings, Alexander M.; Nguyen, Jennifer N.; Hamm, Danielle C.; Donohue, Laura K.; Harrison, Melissa M.; Wildonger, Jill; O’Connor-Giles, Kate M.

    2013-01-01

    We have adapted a bacterial CRISPR RNA/Cas9 system to precisely engineer the Drosophila genome and report that Cas9-mediated genomic modifications are efficiently transmitted through the germline. This RNA-guided Cas9 system can be rapidly programmed to generate targeted alleles for probing gene function in Drosophila.

  14. Enzymic and structural studies on Drosophila alcohol dehydrogenase and other short-chain dehydrogenases/reductases

    NARCIS (Netherlands)

    Smilda, T; Kamminga, AH; Reinders, P; Baron, W; Vlieg, JETV; Beintema, JJ

    2001-01-01

    Enzymic and structural studies on Drosophila alcohol dehydrogenases and other short-chain dehydrogenases/reductases (SDRs) are presented. Like alcohol dehydrogenases from other Drosophila species, the enzyme from D, simulans is more active on secondary than on primary alcohols, although ethanol is i

  15. Non-crop plants used as hosts by Drosophila suzukii in Europe

    NARCIS (Netherlands)

    Kenis, Marc; Tonina, Lorenzo; Eschen, René; Sluis, van der Bart; Sancassani, Manuel; Mori, Nicola; Haye, Tim; Helsen, Herman

    2016-01-01

    The invasive spotted wing drosophila Drosophila suzukii, a fruit fly of Asian origin, is a major pest of a wide variety of berry and stone fruits in Europe. One of the characteristics of this fly is its wide host range. A better knowledge of its host range outside cultivated areas is essential to

  16. Molecular cloning and genomic organization of an allatostatin preprohormone from Drosophila melanogaster

    DEFF Research Database (Denmark)

    Lenz, C; Williamson, M; Grimmelikhuijzen, C J

    2000-01-01

    insect allatostatins. This resulted in alignment with a DNA sequence coding for some Drosophila allatostatins (drostatins). Using PCR with oligonucleotide primers directed against the presumed exons of this Drosophila allatostatin gene and subsequent 3'- and 5'-RACE, we were able to clone its c...

  17. Visualization of Actin Cytoskeletal Dynamics in Fixed and Live Drosophila Egg Chambers.

    Science.gov (United States)

    Groen, Christopher M; Tootle, Tina L

    2015-01-01

    Visualization of actin cytoskeletal dynamics is critical for understanding the spatial and temporal regulation of actin remodeling. Drosophila oogenesis provides an excellent model system for visualizing the actin cytoskeleton. Here, we present methods for imaging the actin cytoskeleton in Drosophila egg chambers in both fixed samples by phalloidin staining and in live egg chambers using transgenic actin labeling tools.

  18. The Drosophila gene brainiac encodes a glycosyltransferase putatively involved in glycosphingolipid synthesis

    DEFF Research Database (Denmark)

    Schwientek, Tilo; Keck, Birgit; Levery, Steven B;

    2002-01-01

    The Drosophila genes fringe and brainiac exhibit sequence similarities to glycosyltransferases. Drosophila and mammalian fringe homologs encode UDP-N-acetylglucosamine:fucose-O-Ser beta1,3-N-acetylglucosaminyltransferases that modulate the function of Notch family receptors. The biological function...

  19. The neuropeptide allatostatin A regulates metabolism and feeding decisions in Drosophila

    DEFF Research Database (Denmark)

    Hentze, Julie Lilith; Carlsson, Mikael A.; Kondo, Shu;

    2015-01-01

    and energy mobilization are regulated by the glucagon-related adipokinetic hormone (AKH) and the Drosophila insulin-like peptides (DILPs). Here, we provide evidence that the Drosophila neuropeptide Allatostatin A (AstA) regulates AKH and DILP signaling. The AstA receptor gene, Dar-2, is expressed in both...

  20. Engineered decoherence: Characterization and suppression

    Science.gov (United States)

    Hegde, Swathi S.; Mahesh, T. S.

    2014-06-01

    Due to omnipresent environmental interferences, quantum coherences inevitably undergo irreversible transformations over certain time scales, thus leading to the loss of encoded information. This process, known as decoherence, has been a major obstacle in realizing efficient quantum information processors. Understanding the mechanism of decoherence is crucial in developing tools to inhibit it. Here we utilize a method proposed by Teklemariam et al. [Phys. Rev. A 67, 062316 (2003), 10.1103/PhysRevA.67.062316] to engineer artificial decoherence in the system qubits by randomly perturbing their surrounding ancilla qubits. Using a two-qubit nuclear magnetic resonance quantum register, we characterize the artificial decoherence by noise spectroscopy and quantum process tomography. Further, we study the efficacy of dynamical decoupling sequences in suppressing the artificial decoherence. Here we describe the experimental results and their comparisons with theoretical simulations.

  1. Polypyrrole Actuators for Tremor Suppression

    DEFF Research Database (Denmark)

    Skaarup, Steen; Mogensen, Naja; Bay, Lasse;

    2003-01-01

    Neurological tremor affecting limbs can be divided into at least 6 different types with frequencies ranging from 2 to about 20 Hz. In order to alleviate the symptoms by suppressing the tremor, sensing and actuation systems able to perform at these frequencies are needed. Electroactive polymers...... exemplify 'soft actuator' technology that may be especially suitable for use in conjunction with human limbs. The electrochemical and mechanical properties of polypyrrole dodecyl benzene sulphonate actuator films have been studied with this application in mind. The results show that the time constants...... for the change of length and for the stiffness change are significantly different - the stiffness change being about 10 times faster. Both force measurements and Electrochemical Quartz Crystal Microbalance measurements indicate that the actuation process is complex and involves at least two different processes...

  2. How to suppress undesired synchronization

    CERN Document Server

    Louzada, V H P; Andrade, J S; Herrmann, H J

    2012-01-01

    It is delightful to observe the emergence of synchronization in the blinking of fireflies to attract partners and preys. Other charming examples of synchronization can also be found in a wide range of phenomena such as, e.g., neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in communication networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge of the system, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement in mitigation is observed when contrarians sit at the highly connected ele...

  3. Continuous flash suppression reduces negative afterimages.

    Science.gov (United States)

    Tsuchiya, Naotsugu; Koch, Christof

    2005-08-01

    Illusions that produce perceptual suppression despite constant retinal input are used to manipulate visual consciousness. Here we report on a powerful variant of existing techniques, continuous flash suppression. Distinct images flashed successively at approximately 10 Hz into one eye reliably suppress an image presented to the other eye. The duration of perceptual suppression is at least ten times greater than that produced by binocular rivalry. Using this tool we show that the strength of the negative afterimage of an adaptor was reduced by half when it was perceptually suppressed by input from the other eye. The more completely the adaptor was suppressed, the more strongly the afterimage intensity was reduced. Paradoxically, trial-to-trial visibility of the adaptor did not correlate with the degree of reduction. Our results imply that formation of afterimages involves neuronal structures that access input from both eyes but that do not correspond directly to the neuronal correlates of perceptual awareness. PMID:15995700

  4. MEK5 suppresses osteoblastic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Kaneshiro, Shoichi [Department of Orthopaedic Surgery, Japan Community Health Care Organization Osaka Hospital, 4-2-78 Fukushima, Fukushima Ward, Osaka City, Osaka 553-0003 (Japan); Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Otsuki, Dai; Yoshida, Kiyoshi; Yoshikawa, Hideki [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Higuchi, Chikahisa, E-mail: c-higuchi@umin.ac.jp [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-07-31

    Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and is activated by its upstream kinase, MAPK kinase 5 (MEK5), which is a member of the MEK family. Although the role of MEK5 has been investigated in several fields, little is known about its role in osteoblastic differentiation. In this study, we have demonstrated the role of MEK5 in osteoblastic differentiation in mouse preosteoblastic MC3T3-E1 cells and bone marrow stromal ST2 cells. We found that treatment with BIX02189, an inhibitor of MEK5, increased alkaline phosphatase (ALP) activity and the gene expression of ALP, osteocalcin (OCN) and osterix, as well as it enhanced the calcification of the extracellular matrix. Moreover, osteoblastic cell proliferation decreased at a concentration of greater than 0.5 μM. In addition, knockdown of MEK5 using siRNA induced an increase in ALP activity and in the gene expression of ALP, OCN, and osterix. In contrast, overexpression of wild-type MEK5 decreased ALP activity and attenuated osteoblastic differentiation markers including ALP, OCN and osterix, but promoted cell proliferation. In summary, our results indicated that MEK5 suppressed the osteoblastic differentiation, but promoted osteoblastic cell proliferation. These results implied that MEK5 may play a pivotal role in cell signaling to modulate the differentiation and proliferation of osteoblasts. Thus, inhibition of MEK5 signaling in osteoblasts may be of potential use in the treatment of osteoporosis. - Highlights: • MEK5 inhibitor BIX02189 suppresses proliferation of osteoblasts. • MEK5 knockdown and MEK5 inhibitor promote differentiation of osteoblasts. • MEK5 overexpression inhibits differentiation of osteoblasts.

  5. Identification and Characterization of Genes Involved in Embryonic Crystal Cell Formation During Drosophila Hematopoiesis

    Science.gov (United States)

    Milchanowski, Allison B.; Henkenius, Amy L.; Narayanan, Maya; Hartenstein, Volker; Banerjee, Utpal

    2004-01-01

    Parallels between vertebrate and Drosophila hematopoiesis add to the value of flies as a model organism to gain insights into blood development. The Drosophila hematopoietic system is composed of at least three classes of terminally differentiated blood cells: plasmatocytes, crystal cells, and lamellocytes. Recent studies have identified transcriptional and signaling pathways in Drosophila involving proteins similar to those seen in human blood development. To identify additional genes involved in Drosophila hematopoiesis, we have conducted a P-element-based genetic screen to isolate mutations that affect embryonic crystal cell development. Using a marker of terminally differentiated crystal cells, we screened 1040 P-element-lethal lines located on the second and third chromosomes and identified 44 individual lines that affect crystal cell development. Identifying novel genes and pathways involved in Drosophila hematopoiesis is likely to provide further insights into mammalian hematopoietic development and disorders. PMID:15454546

  6. Rearing the Fruit Fly Drosophila melanogaster Under Axenic and Gnotobiotic Conditions.

    Science.gov (United States)

    Koyle, Melinda L; Veloz, Madeline; Judd, Alec M; Wong, Adam C-N; Newell, Peter D; Douglas, Angela E; Chaston, John M

    2016-01-01

    The influence of microbes on myriad animal traits and behaviors has been increasingly recognized in recent years. The fruit fly Drosophila melanogaster is a model for understanding microbial interactions with animal hosts, facilitated by approaches to rear large sample sizes of Drosophila under microorganism-free (axenic) conditions, or with defined microbial communities (gnotobiotic). This work outlines a method for collection of Drosophila embryos, hypochlorite dechorionation and sterilization, and transfer to sterile diet. Sterilized embryos are transferred to sterile diet in 50 ml centrifuge tubes, and developing larvae and adults remain free of any exogenous microbes until the vials are opened. Alternatively, flies with a defined microbiota can be reared by inoculating sterile diet and embryos with microbial species of interest. We describe the introduction of 4 bacterial species to establish a representative gnotobiotic microbiota in Drosophila. Finally, we describe approaches for confirming bacterial community composition, including testing if axenic Drosophila remain bacteria-free into adulthood. PMID:27500374

  7. Two Effects of Firepower: Attrition and Suppression

    OpenAIRE

    Hughes, Wayne P.

    1995-01-01

    A new basis for the quantitative study of ground combat is introduced that argues the inadequacy of attrition models and the need to incorporate the effects of suppression of the enemy with firepower. A quantitative approach to suppression of enemy fire is offered. Then an analysis shows that the effect of own fire in suppressing enemy fire will, in suitable, frequent circumstances, reverse the conclusions derived from the Lanchester square law, so that the sq...

  8. Psychopathology and Thought Suppression: A Quantitative Review

    OpenAIRE

    Magee, Joshua C; Harden, K. Paige; Teachman, Bethany A.

    2012-01-01

    Recent theories of psychopathology have suggested that thought suppression intensifies the persistence of intrusive thoughts, and proposed that difficulty with thought suppression may differ between groups with and without psychopathology. The current meta-analytic review evaluates empirical evidence for difficulty with thought suppression as a function of the presence and specific type of psychopathology. Based on theoretical proposals from the psychopathology literature, diagnosed and analo...

  9. Deconstructing Interocular Suppression: Attention and Divisive Normalization.

    Science.gov (United States)

    Li, Hsin-Hung; Carrasco, Marisa; Heeger, David J

    2015-10-01

    In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression), the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature) and divisive normalization contribute to interocular suppression. PMID:26517321

  10. NOVEL BIPHASE CODE -INTEGRATED SIDELOBE SUPPRESSION CODE

    Institute of Scientific and Technical Information of China (English)

    Wang Feixue; Ou Gang; Zhuang Zhaowen

    2004-01-01

    A kind of novel binary phase code named sidelobe suppression code is proposed in this paper. It is defined to be the code whose corresponding optimal sidelobe suppression filter outputs the minimum sidelobes. It is shown that there do exist sidelobe suppression codes better than the conventional optimal codes-Barker codes. For example, the sidelobe suppression code of length 11 with filter of length 39 has better sidelobe level up to 17dB than that of Barker code with the same code length and filter length.

  11. Organ identity specification factor WGE localizes to the histone locus body and regulates histone expression to ensure genomic stability in Drosophila.

    Science.gov (United States)

    Ozawa, Nao; Furuhashi, Hirofumi; Masuko, Keita; Numao, Eriko; Makino, Takashi; Yano, Tamaki; Kurata, Shoichiro

    2016-05-01

    Over-expression of Winged-Eye (WGE) in the Drosophila eye imaginal disc induces an eye-to-wing transformation. Endogenous WGE is required for organ development, and wge-deficient mutants exhibit growth arrest at the larval stage, suggesting that WGE is critical for normal growth. The function of WGE, however, remains unclear. Here, we analyzed the subcellular localization of WGE to gain insight into its endogenous function. Immunostaining showed that WGE localized to specific nuclear foci called the histone locus body (HLB), an evolutionarily conserved nuclear body required for S phase-specific histone mRNA production. Histone mRNA levels and protein levels in cytosolic fractions were aberrantly up-regulated in wge mutant larva, suggesting a role for WGE in regulating histone gene expression. Genetic analyses showed that wge suppresses position-effect variegation, and that WGE and a HLB component Mute appears to be synergistically involved in heterochromatin formation. Further supporting a role in chromatin regulation, wge-deficient mutants showed derepression of retrotransposons and increased γH2Av signals, a DNA damage marker. These findings suggest that WGE is a component of HLB in Drosophila with a role in heterochromatin formation and transposon silencing. We propose that WGE at HLB contributes to genomic stability and development by regulating heterochromatin structure via histone gene regulation. PMID:27145109

  12. The N-terminal domain of the Drosophila retinoblastoma protein Rbf1 interacts with ORC and associates with chromatin in an E2F independent manner.

    Directory of Open Access Journals (Sweden)

    Joseph Ahlander

    Full Text Available BACKGROUND: The retinoblastoma (Rb tumor suppressor protein can function as a DNA replication inhibitor as well as a transcription factor. Regulation of DNA replication may occur through interaction of Rb with the origin recognition complex (ORC. PRINCIPAL FINDINGS: We characterized the interaction of Drosophila Rb, Rbf1, with ORC. Using expression of proteins in Drosophila S2 cells, we found that an N-terminal Rbf1 fragment (amino acids 1-345 is sufficient for Rbf1 association with ORC but does not bind to dE2F1. We also found that the C-terminal half of Rbf1 (amino acids 345-845 interacts with ORC. We observed that the amino-terminal domain of Rbf1 localizes to chromatin in vivo and associates with chromosomal regions implicated in replication initiation, including colocalization with Orc2 and acetylated histone H4. CONCLUSIONS/SIGNIFICANCE: Our results suggest that Rbf1 can associate with ORC and chromatin through domains independent of the E2F binding site. We infer that Rbf1 may play a role in regulating replication directly through its association with ORC and/or chromatin factors other than E2F. Our data suggest an important role for retinoblastoma family proteins in cell proliferation and tumor suppression through interaction with the replication initiation machinery.

  13. Myt1 inhibition of Cyclin A/Cdk1 is essential for fusome integrity and premeiotic centriole engagement in Drosophila spermatocytes.

    Science.gov (United States)

    Varadarajan, Ramya; Ayeni, Joseph; Jin, Zhigang; Homola, Ellen; Campbell, Shelagh D

    2016-07-01

    Regulation of cell cycle arrest in premeiotic G2 phase coordinates germ cell maturation and meiotic cell division with hormonal and developmental signals by mechanisms that control Cyclin B synthesis and inhibitory phosphorylation of the M-phase kinase, Cdk1. In this study, we investigated how inhibitory phosphorylation of Cdk1 by Myt1 kinase regulates premeiotic G2 phase of Drosophila male meiosis. Immature spermatocytes lacking Myt1 activity exhibit two distinct defects: disrupted intercellular bridges (fusomes) and premature centriole disengagement. As a result, the myt1 mutant spermatocytes enter meiosis with multipolar spindles. These myt1 defects can be suppressed by depletion of Cyclin A activity or ectopic expression of Wee1 (a partially redundant Cdk1 inhibitory kinase) and phenocopied by expression of a Cdk1F mutant defective for inhibitory phosphorylation. We therefore conclude that Myt1 inhibition of Cyclin A/Cdk1 is essential for normal fusome behavior and centriole engagement during premeiotic G2 arrest of Drosophila male meiosis. The novel meiotic functions we discovered for Myt1 kinase are spatially and temporally distinct from previously described functions of Myt1 as an inhibitor of Cyclin B/Cdk1 to regulate G2/MI timing. PMID:27170181

  14. Emotional and non-emotional memories are suppressible under direct suppression instructions

    NARCIS (Netherlands)

    K. van Schie (Kevin); E.G. Geraerts (Elke); M.C. Anderson (Michael)

    2013-01-01

    textabstractResearch on retrieval suppression has produced varying results concerning whether negatively valenced memories are more or less suppressible than neutral memories. This variability may arise if, across studies, participants adopt different approaches to memory control. Cognitive and neur

  15. Emotional and non-emotional memories are suppressible under direct suppression instructions

    OpenAIRE

    van Schie, Kevin; Geraerts, Elke; Anderson, Michael

    2013-01-01

    textabstractResearch on retrieval suppression has produced varying results concerning whether negatively valenced memories are more or less suppressible than neutral memories. This variability may arise if, across studies, participants adopt different approaches to memory control. Cognitive and neurobiological research points to two mechanisms that achieve retrieval suppression: thought-substitution and direct suppression (Benoit & Anderson, 2012; Bergström, de Fockert, & Richardson-Klavehn, ...

  16. Consequences of stereotype suppression and internal suppression motivation : A self-regulation approach

    NARCIS (Netherlands)

    Gordijn, EH; Hindriks, [No Value; Koomen, W; Dijksterhuis, A; Van Knippenberg, A; Hindriks, I; van Knipppenberg, A.

    2004-01-01

    The present research studied the effects of suppression of stereotypes on subsequent stereotyping. Moreover, the moderating influence of motivation to suppress stereotypes was examined. The first three experiments showed that suppression of stereotypes leads to the experience of engaging in self-con

  17. Drosophila spaghetti and doubletime link the circadian clock and light to caspases, apoptosis and tauopathy.

    Directory of Open Access Journals (Sweden)

    John C Means

    2015-05-01

    Full Text Available While circadian dysfunction and neurodegeneration are correlated, the mechanism for this is not understood. It is not known if age-dependent circadian dysfunction leads to neurodegeneration or vice-versa, and the proteins that mediate the effect remain unidentified. Here, we show that the knock-down of a regulator (spag of the circadian kinase Dbt in circadian cells lowers Dbt levels abnormally, lengthens circadian rhythms and causes expression of activated initiator caspase (Dronc in the optic lobes during the middle of the day or after light pulses at night. Likewise, reduced Dbt activity lengthens circadian period and causes expression of activated Dronc, and a loss-of-function mutation in Clk also leads to expression of activated Dronc in a light-dependent manner. Genetic epistasis experiments place Dbt downstream of Spag in the pathway, and Spag-dependent reductions of Dbt are shown to require the proteasome. Importantly, activated Dronc expression due to reduced Spag or Dbt activity occurs in cells that do not express the spag RNAi or dominant negative Dbt and requires PDF neuropeptide signaling from the same neurons that support behavioral rhythms. Furthermore, reduction of Dbt or Spag activity leads to Dronc-dependent Drosophila Tau cleavage and enhanced neurodegeneration produced by human Tau in a fly eye model for tauopathy. Aging flies with lowered Dbt or Spag function show markers of cell death as well as behavioral deficits and shortened lifespans, and even old wild type flies exhibit Dbt modification and activated caspase at particular times of day. These results suggest that Dbt suppresses expression of activated Dronc to prevent Tau cleavage, and that the circadian clock defects confer sensitivity to expression of activated Dronc in response to prolonged light. They establish a link between the circadian clock factors, light, cell death pathways and Tau toxicity, potentially via dysregulation of circadian neuronal remodeling in

  18. Genetic and chemical modifiers of a CUG toxicity model in Drosophila.

    Directory of Open Access Journals (Sweden)

    Amparo Garcia-Lopez

    Full Text Available Non-coding CUG repeat expansions interfere with the activity of human Muscleblind-like (MBNL proteins contributing to myotonic dystrophy 1 (DM1. To understand this toxic RNA gain-of-function mechanism we developed a Drosophila model expressing 60 pure and 480 interrupted CUG repeats in the context of a non-translatable RNA. These flies reproduced aspects of the DM1 pathology, most notably nuclear accumulation of CUG transcripts, muscle degeneration, splicing misregulation, and diminished Muscleblind function in vivo. Reduced Muscleblind activity was evident from the sensitivity of CUG-induced phenotypes to a decrease in muscleblind genetic dosage and rescue by MBNL1 expression, and further supported by the co-localization of Muscleblind and CUG repeat RNA in ribonuclear foci. Targeted expression of CUG repeats to the developing eye and brain mushroom bodies was toxic leading to rough eyes and semilethality, respectively. These phenotypes were utilized to identify genetic and chemical modifiers of the CUG-induced toxicity. 15 genetic modifiers of the rough eye phenotype were isolated. These genes identify putative cellular processes unknown to be altered by CUG repeat RNA, and they include mRNA export factor Aly, apoptosis inhibitor Thread, chromatin remodelling factor Nurf-38, and extracellular matrix structural component Viking. Ten chemical compounds suppressed the semilethal phenotype. These compounds significantly improved viability of CUG expressing flies and included non-steroidal anti-inflammatory agents (ketoprofen, muscarinic, cholinergic and histamine receptor inhibitors (orphenadrine, and drugs that can affect sodium and calcium metabolism such as clenbuterol and spironolactone. These findings provide new insights into the DM1 phenotype, and suggest novel candidates for DM1 treatments.

  19. Plant insecticide L-canavanine repels Drosophila via the insect orphan GPCR DmX.

    Directory of Open Access Journals (Sweden)

    Christian Mitri

    2009-06-01

    Full Text Available For all animals, the taste sense is crucial to detect and avoid ingesting toxic molecules. Many toxins are synthesized by plants as a defense mechanism against insect predation. One example of such a natural toxic molecule is L-canavanine, a nonprotein amino acid found in the seeds of many legumes. Whether and how insects are informed that some plants contain L-canavanine remains to be elucidated. In insects, the taste sense relies on gustatory receptors forming the gustatory receptor (Gr family. Gr proteins display highly divergent sequences, suggesting that they could cover the entire range of tastants. However, one cannot exclude the possibility of evolutionarily independent taste receptors. Here, we show that L-canavanine is not only toxic, but is also a repellent for Drosophila. Using a pharmacogenetic approach, we find that flies sense food containing this poison by the DmX receptor. DmXR is an insect orphan G-protein-coupled receptor that has partially diverged in its ligand binding pocket from the metabotropic glutamate receptor family. Blockade of DmXR function with an antagonist lowers the repulsive effect of L-canavanine. In addition, disruption of the DmXR encoding gene, called mangetout (mtt, suppresses the L-canavanine repellent effect. To avoid the ingestion of L-canavanine, DmXR expression is required in bitter-sensitive gustatory receptor neurons, where it triggers the premature retraction of the proboscis, thus leading to the end of food searching. These findings show that the DmX receptor, which does not belong to the Gr family, fulfills a gustatory function necessary to avoid eating a natural toxin.

  20. Mechanisms underlying hypoxia tolerance in Drosophila melanogaster: hairy as a metabolic switch.

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    Dan Zhou

    2008-10-01

    Full Text Available Hypoxia-induced cell injury has been related to multiple pathological conditions. In order to render hypoxia-sensitive cells and tissues resistant to low O2 environment, in this current study, we used Drosophila melanogaster as a model to dissect the mechanisms underlying hypoxia-tolerance. A D. melanogaster strain that lives perpetually in an extremely low-oxygen environment (4% O2, an oxygen level that is equivalent to that over about 4,000 m above Mt. Everest was generated through laboratory selection pressure using a continuing reduction of O2 over many generations. This phenotype is genetically stable since selected flies, after several generations in room air, survive at this low O2 level. Gene expression profiling showed striking differences between tolerant and naïve flies, in larvae and adults, both quantitatively and qualitatively. Up-regulated genes in the tolerant flies included signal transduction pathways (e.g., Notch and Toll/Imd pathways, but metabolic genes were remarkably down-regulated in the larvae. Furthermore, a different allelic frequency and enzymatic activity of the triose phosphate isomerase (TPI was present in the tolerant versus naïve flies. The transcriptional suppressor, hairy, was up-regulated in the microarrays and its binding elements were present in the regulatory region of the specifically down-regulated metabolic genes but not others, and mutations in hairy significantly reduced hypoxia tolerance. We conclude that, the hypoxia-selected flies: (a altered their gene expression and genetic code, and (b coordinated their metabolic suppression, especially during development, with hairy acting as a metabolic switch, thus playing a crucial role in hypoxia-tolerance.

  1. Olfactory habituation in Drosophila-odor encoding and its plasticity in the antennal lobe.

    Science.gov (United States)

    Twick, Isabell; Lee, John Anthony; Ramaswami, Mani

    2014-01-01

    A ubiquitous feature of an animal's response to an odorant is that it declines when the odorant is frequently or continuously encountered. This decline in olfactory response, termed olfactory habituation, can have temporally or mechanistically different forms. The neural circuitry of the fruit fly Drosophila melanogaster's olfactory system is well defined in terms of component cells, which are readily accessible to functional studies and genetic manipulation. This makes it a particularly useful preparation for the investigation of olfactory habituation. In addition, the insect olfactory system shares many architectural and functional similarities with mammalian olfactory systems, suggesting that olfactory mechanisms in insects may be broadly relevant. In this chapter, we discuss the likely mechanisms of olfactory habituation in context of the participating cell types, their connectivity, and their roles in sensory processing. We overview the structure and function of key cell types, the mechanisms that stimulate them, and how they transduce and process odor signals. We then consider how each stage of olfactory processing could potentially contribute to behavioral habituation. After this, we overview a variety of recent mechanistic studies that point to an important role for potentiation of inhibitory synapses in the primary olfactory processing center, the antennal lobe, in driving the reduced response to familiar odorants. Following the discussion of mechanisms for short- and long-term olfactory habituation, we end by considering how these mechanisms may be regulated by neuromodulators, which likely play key roles in the induction, gating, or suppression of habituated behavior, and speculate on the relevance of these processes for other forms of learning and memory.

  2. Genetic modifiers of MeCP2 function in Drosophila.

    Directory of Open Access Journals (Sweden)

    Holly N Cukier

    Full Text Available The levels of methyl-CpG-binding protein 2 (MeCP2 are critical for normal post-natal development and function of the nervous system. Loss of function of MeCP2, a transcriptional regulator involved in chromatin remodeling, causes classic Rett syndrome (RTT as well as other related conditions characterized by autism, learning disabilities, or mental retardation. Increased dosage of MeCP2 also leads to clinically similar neurological disorders and mental retardation. To identify molecular mechanisms capable of compensating for altered MeCP2 levels, we generated transgenic Drosophila overexpressing human MeCP2. We find that MeCP2 associates with chromatin and is phosphorylated at serine 423 in Drosophila, as is found in mammals. MeCP2 overexpression leads to anatomical (i.e., disorganized eyes, ectopic wing veins and behavioral (i.e., motor dysfunction abnormalities. We used a candidate gene approach to identify genes that are able to compensate for abnormal phenotypes caused by MeCP2 increased activity. These genetic modifiers include other chromatin remodeling genes (Additional sex combs, corto, osa, Sex combs on midleg, and trithorax, the kinase tricornered, the UBE3A target pebble, and Drosophila homologues of the MeCP2 physical interactors Sin3a, REST, and N-CoR. These findings demonstrate that anatomical and behavioral phenotypes caused by MeCP2 activity can be ameliorated by altering other factors that might be more amenable to manipulation than MeCP2 itself.

  3. Conserved mechanisms of tumorigenesis in the Drosophila adult midgut.

    Directory of Open Access Journals (Sweden)

    Òscar Martorell

    Full Text Available Whereas the series of genetic events leading to colorectal cancer (CRC have been well established, the precise functions that these alterations play in tumor progression and how they disrupt intestinal homeostasis remain poorly characterized. Activation of the Wnt/Wg signaling pathway by a mutation in the gene APC is the most common trigger for CRC, inducing benign lesions that progress to carcinomas due to the accumulation of other genetic alterations. Among those, Ras mutations drive tumour progression in CRC, as well as in most epithelial cancers. As mammalian and Drosophila's intestines share many similarities, we decided to explore the alterations induced in the Drosophila midgut by the combined activation of the Wnt signaling pathway with gain of function of Ras signaling in the intestinal stem cells. Here we show that compound Apc-Ras clones, but not clones bearing the individual mutations, expand as aggressive intestinal tumor-like outgrowths. These lesions reproduce many of the human CRC hallmarks such as increased proliferation, blockade of cell differentiation and cell polarity and disrupted organ architecture. This process is followed by expression of tumoral markers present in human lesions. Finally, a metabolic behavioral assay shows that these flies suffer a progressive deterioration in intestinal homeostasis, providing a simple readout that could be used in screens for tumor modifiers or therapeutic compounds. Taken together, our results illustrate the conservation of the mechanisms of CRC tumorigenesis in Drosophila, providing an excellent model system to unravel the events that, upon mutation in Apc and Ras, lead to CRC initiation and progression.

  4. Chemicals and chemoreceptors: ecologically relevant signals driving behavior in Drosophila.

    Directory of Open Access Journals (Sweden)

    Ana eDepetris-Chauvin

    2015-04-01

    Full Text Available Insects encounter a vast repertoire of chemicals in their natural environment, which can signal positive stimuli like the presence of a food source, a potential mate, or a suitable oviposition site as well as negative stimuli such as competitors, predators, or toxic substances reflecting danger. The presence of specialized chemoreceptors like taste and olfactory receptors allow animals to detect chemicals at short and long distances and accordingly, trigger proper behaviors towards these stimuli. Since the first description of olfactory and taste receptors in Drosophila fifteen years ago, our knowledge on the identity, properties, and function of specific chemoreceptors has increased exponentially. In the last years, multidisciplinary approaches combining genetic tools with electrophysiological techniques, behavioral recording, evolutionary analysis, and chemical ecology studies are shedding light on our understanding on the ecological relevance of specific chemoreceptors for the survival of Drosophila in their natural environment. In this review we discuss the current knowledge on chemoreceptors of both the olfactory and taste systems of the fruitfly. We focus on the relevance of particular receptors for the detection of ecologically relevant cues such as pheromones, food sources, and toxic compounds, and we comment on the behavioral changes that the detection of these chemicals induce in the fly. In particular, we give an updated outlook of the chemical communication displayed during one of the most important behaviors for fly survival, the courtship behavior. Finally, the ecological relevance of specific chemicals can vary depending on the niche occupied by the individual. In that regard, in this review we also highlight the contrast between adult and larval systems and we propose that these differences could reflect distinctive requirements depending on the change of ecological niche occupied by Drosophila along its life cycle.

  5. Intracellular shuttling of a Drosophila APC tumour suppressor homolog

    Directory of Open Access Journals (Sweden)

    Mieszczanek Julius

    2004-09-01

    Full Text Available Abstract Background The Adenomatous polyposis coli (APC tumour suppressor is found in multiple discrete subcellular locations, which may reflect sites of distinct functions. In Drosophila epithelial cells, the predominant APC relative (E-APC is concentrated at the apicolateral adherens junctions. Genetic analysis indicates that this junctional association is critical for the function of E-APC in Wnt signalling and in cellular adhesion. Here, we ask whether the junctional association of E-APC is stable, or whether E-APC shuttles between the plasma membrane and the cytoplasm. Results We generated a Drosophila strain that expresses E-APC (dAPC2 tagged with green fluorescent protein (GFP-E-APC and we analysed its junctional association with fluorescence recovery after photobleaching (FRAP experiments in live embryos. This revealed that the junctional association of GFP-E-APC in epithelial cells is highly dynamic, and is far less stable than that of the structural components of the adherens junctions, E-cadherin, α-catenin and Armadillo. The shuttling of GFP-E-APC to and from the plasma membrane is unaltered in mutants of Drosophila glycogen synthase kinase 3 (GSK3, which mimic constitutive Wingless signalling. However, the stability of E-APC is greatly reduced in these mutants, explaining their apparent delocalisation from the plasma membrane as previously observed. Finally, we show that GFP-E-APC forms dynamic patches at the apical plasma membrane of late embryonic epidermal cells that form denticles, and that it shuttles up and down the axons of the optic lobe. Conclusions We conclude that E-APC is a highly mobile protein that shuttles constitutively between distinct subcellular locations.

  6. Circadian transcription contributes to core period determination in Drosophila.

    Directory of Open Access Journals (Sweden)

    Sebastian Kadener

    2008-05-01

    Full Text Available The Clock-Cycle (CLK-CYC heterodimer constitutes a key circadian transcription complex in Drosophila. CYC has a DNA-binding domain but lacks an activation domain. Previous experiments also indicate that most of the transcriptional activity of CLK-CYC derives from the glutamine-rich region of its partner CLK. To address the role of transcription in core circadian timekeeping, we have analyzed the effects of a CYC-viral protein 16 (VP16 fusion protein in the Drosophila system. The addition of this potent and well-studied viral transcriptional activator (VP16 to CYC imparts to the CLK-CYC-VP16 complex strongly enhanced transcriptional activity relative to that of CLK-CYC. This increase is manifested in flies expressing CYC-VP16 as well as in S2 cells. These flies also have increased levels of CLK-CYC direct target gene mRNAs as well as a short period, implicating circadian transcription in period determination. A more detailed examination of reporter gene expression in CYC-VP16-expressing flies suggests that the short period is due at least in part to a more rapid transcriptional phase. Importantly, the behavioral effects require a period (per promoter and are therefore unlikely to be merely a consequence of generally higher PER levels. This indicates that the CLK-CYC-VP16 behavioral effects are a consequence of increased per transcription. All of this also suggests that the timing of transcriptional activation and not the activation itself is the key event responsible for the behavioral effects observed in CYC-VP16-expressing flies. The results taken together indicate that circadian transcription contributes to core circadian function in Drosophila.

  7. The PIKE homolog Centaurin gamma regulates developmental timing in Drosophila.

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    Anna Lisa Gündner

    Full Text Available Phosphoinositide-3-kinase enhancer (PIKE proteins encoded by the PIKE/CENTG1 gene are members of the gamma subgroup of the Centaurin superfamily of small GTPases. They are characterized by their chimeric protein domain architecture consisting of a pleckstrin homology (PH domain, a GTPase-activating (GAP domain, Ankyrin repeats as well as an intrinsic GTPase domain. In mammals, three PIKE isoforms with variations in protein structure and subcellular localization are encoded by the PIKE locus. PIKE inactivation in mice results in a broad range of defects, including neuronal cell death during brain development and misregulation of mammary gland development. PIKE -/- mutant mice are smaller, contain less white adipose tissue, and show insulin resistance due to misregulation of AMP-activated protein kinase (AMPK and insulin receptor/Akt signaling. here, we have studied the role of PIKE proteins in metabolic regulation in the fly. We show that the Drosophila PIKE homolog, ceng1A, encodes functional GTPases whose internal GAP domains catalyze their GTPase activity. To elucidate the biological function of ceng1A in flies, we introduced a deletion in the ceng1A gene by homologous recombination that removes all predicted functional PIKE domains. We found that homozygous ceng1A mutant animals survive to adulthood. In contrast to PIKE -/- mouse mutants, genetic ablation of Drosophila ceng1A does not result in growth defects or weight reduction. Although metabolic pathways such as insulin signaling, sensitivity towards starvation and mobilization of lipids under high fed conditions are not perturbed in ceng1A mutants, homozygous ceng1A mutants show a prolonged development in second instar larval stage, leading to a late onset of pupariation. In line with these results we found that expression of ecdysone inducible genes is reduced in ceng1A mutants. Together, we propose a novel role for Drosophila Ceng1A in regulating ecdysone signaling-dependent second to

  8. Cytochrome P450-dependent metabolism of caffeine in Drosophila melanogaster.

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    Alexandra Coelho

    Full Text Available Caffeine (1, 3, 7-trimethylxanthine, an alkaloid produced by plants, has antioxidant and insecticide properties that can affect metabolism and cognition. In vertebrates, the metabolites derived from caffeine have been identified, and their functions have been characterized. However, the metabolites of caffeine in insects remain unknown. Thus, using radiolabelled caffeine, we have identified some of the primary caffeine metabolites produced in the body of Drosophila melanogaster males, including theobromine, paraxanthine and theophylline. In contrast to mammals, theobromine was the predominant metabolite (paraxanthine in humans; theophylline in monkeys; 1, 3, 7-trimethyluric acid in rodents. A transcriptomic screen of Drosophila flies exposed to caffeine revealed the coordinated variation of a large set of genes that encode xenobiotic-metabolizing proteins, including several cytochromes P450s (CYPs that were highly overexpressed. Flies treated with metyrapone--an inhibitor of CYP enzymes--showed dramatically decreased caffeine metabolism, indicating that CYPs are involved in this process. Using interference RNA genetic silencing, we measured the metabolic and transcriptomic effect of three candidate CYPs. Silencing of CYP6d5 completely abolished theobromine synthesis, whereas CYP6a8 and CYP12d1 silencing induced different consequences on metabolism and gene expression. Therefore, we characterized several metabolic products and some enzymes potentially involved in the degradation of caffeine. In conclusion, this pioneer approach to caffeine metabolism in insects opens novel perspectives for the investigation of the physiological effects of caffeine metabolites. It also indicates that caffeine could be used as a biomarker to evaluate CYP phenotypes in Drosophila and other insects.

  9. Impacts of suppressing guide on information spreading

    CERN Document Server

    Xu, Jinghong; Ma, Baojun; Wu, Ye

    2015-01-01

    It is quite common that guides are introduced to suppress the information spreading in modern society for different purposes. In this paper, an agent-based model is established to quantitatively analyze the impacts of suppressing guides on information spreading. We find that the spreading threshold depends on the attractiveness of the information and the topology of the social network with no suppressing guides at all. Usually, one would expect that the existence of suppressing guides in the spreading procedure may result in less diffusion of information within the overall network. However, we find that sometimes the opposite is true: the manipulating nodes of suppressing guides may lead to more extensive information spreading when there are audiences with the reversal mind. These results can provide valuable theoretical references to public opinion guidance on various information, e.g., rumor or news spreading.

  10. Impacts of suppressing guide on information spreading

    Science.gov (United States)

    Xu, Jinghong; Zhang, Lin; Ma, Baojun; Wu, Ye

    2016-02-01

    It is quite common that guides are introduced to suppress the information spreading in modern society for different purposes. In this paper, an agent-based model is established to quantitatively analyze the impacts of suppressing guides on information spreading. We find that the spreading threshold depends on the attractiveness of the information and the topology of the social network with no suppressing guides at all. Usually, one would expect that the existence of suppressing guides in the spreading procedure may result in less diffusion of information within the overall network. However, we find that sometimes the opposite is true: the manipulating nodes of suppressing guides may lead to more extensive information spreading when there are audiences with the reversal mind. These results can provide valuable theoretical references to public opinion guidance on various information, e.g., rumor or news spreading.

  11. Transcriptional Activation of the Zygotic Genome in Drosophila.

    Science.gov (United States)

    Harrison, Melissa M; Eisen, Michael B

    2015-01-01

    During the first stages of metazoan development, the genomes of the highly specified sperm and egg must unite and be reprogrammed to allow for the generation of a new organism. This process is controlled by maternally deposited products. Initially, the zygotic genome is largely transcriptionally quiescent, and it is not until hours later that the zygotic genome takes control of development. The transcriptional activation of the zygotic genome is tightly coordinated with the degradation of the maternal products. Here, we review the current understanding of the processes that mediate the reprogramming of the early embryonic genome and facilitate transcriptional activation during the early stages of Drosophila development.

  12. Global genetic change tracks global climate warming in Drosophila subobscura.

    Science.gov (United States)

    Balanyá, Joan; Oller, Josep M; Huey, Raymond B; Gilchrist, George W; Serra, Luis

    2006-09-22

    Comparisons of recent with historical samples of chromosome inversion frequencies provide opportunities to determine whether genetic change is tracking climate change in natural populations. We determined the magnitude and direction of shifts over time (24 years between samples on average) in chromosome inversion frequencies and in ambient temperature for populations of the fly Drosophila subobscura on three continents. In 22 of 26 populations, climates warmed over the intervals, and genotypes characteristic of low latitudes (warm climates) increased in frequency in 21 of those 22 populations. Thus, genetic change in this fly is tracking climate warming and is doing so globally.

  13. Feeding regulates sex pheromone attraction and courtship in Drosophila females

    OpenAIRE

    Sébastien Lebreton; Federica Trona; Felipe Borrero-Echeverry; Florian Bilz; Veit Grabe; Becher, Paul G.; Carlsson, Mikael A.; Nässel, Dick R.; Bill S Hansson; Silke Sachse; Peter Witzgall

    2015-01-01

    In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases, and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of se...

  14. Performance of the Cas9 Nickase System in Drosophila melanogaster

    OpenAIRE

    Ren, Xingjie; Yang, Zhihao; Mao, Decai; Chang, Zai; Qiao, Huan-Huan; Wang, Xia; Sun, Jin; Hu, Qun; Cui, Yan; Liu, Lu-Ping; Ji, Jun-Yuan; Xu, Jiang; Ni, Jian-Quan

    2014-01-01

    Recent studies of the Cas9/sgRNA system in Drosophila melanogaster genome editing have opened new opportunities to generate site-specific mutant collections in a high-throughput manner. However, off-target effects of the system are still a major concern when analyzing mutant phenotypes. Mutations converting Cas9 to a DNA nickase have great potential for reducing off-target effects in vitro. Here, we demonstrated that injection of two plasmids encoding neighboring offset sgRNAs into transgenic...

  15. Genetic Analysis of Micro-environmental Plasticity in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Morgante, Fabio; Sorensen, Daniel A; Sørensen, Peter;

    be genetically variable. This study utilized the Drosophila Genetic Reference Panel (DGRP) to accurately estimate the genetic variance of micro-environmental plasticity for chill coma recovery time and startle response. Estimates of broad sense heritabilities for both traits are substantial (from 0......Quantitative genetic models recognize the potential for genotype by environment interaction, whereby different genotypes have different plastic responses to changes in macro-environmental conditions. Recently, it has been recognized that micro-environmental plasticity (‘residual’ variance) may also...

  16. Prolonged stress induces adaptation of drosophila population to ionizing radiation

    International Nuclear Information System (INIS)

    We studied natural populations of Drosophila melanogaster from radio-contaminated area (Vetka district of Gomel region with 24 Ci/km2 of 137Cs and 0.5 Cu/km2 of 90Sr) and from Berezynski Natural Reserve as a control area (region of Chernobyl catastrophe). Population samples were caught in 2000-2001 years. Natural insect populations from radio-contaminated areas are more resistant to additional irradiation than control populations. Keeping of natural populations under laboratory or vivarium conditions is a strong stress (limited space, overpopulation, other than in nature temperature and light conditions), which increases mutation process and induces unspecific adaptation. (authors)

  17. Modelling of intercellular synchronization in the Drosophila circadian clock

    Institute of Scientific and Technical Information of China (English)

    Wang Jun-Wei; Chen Ai-Min; Zhang Jia-Jun; Yuan Zhan-Jiang; Zhou Tian-Shou

    2009-01-01

    In circadian rhythm generation, intercellular signaling factors are shown to play a crucial role in both sustaining intrinsic cellular rhythmicity and acquiring collective behaviours across a population of circadian neurons. However, the physical mechanism behind their role remains to be fully understood. In this paper, we propose an indirectly coupled multicellular model for the synchronization of Drosophila circadian oscillators combining both intracellular and intercellular dynamics. By simulating different experimental conditions, we find that such an indirect coupling way can synchronize both heterogeneous self-sustained circadian neurons and heterogeneous mutational damped circadian neurons. Moreover, they can also be entrained to ambient light-dark (LD) cycles depending on intercellular signaling.

  18. Longevity and the stress response in Drosophila

    DEFF Research Database (Denmark)

    Vermeulen, Corneel J.; Loeschcke, Volker

    2007-01-01

    substances. Do these same changes in patterns of expression have the ability to mitigate ageing and prolong lifespan? It appears that parts of this response indeed are also associated with extended longevity, whereas some elements are not, due to their high cost or long-term deleterious consequences. Here we...... briefly review the state of the art of research on ageing and longevity in the model organism Drosophila, with focus on the role of the general stress response. We will conclude by contemplating some of the implications of the findings in this research and will suggest several directions for future...

  19. Cryptochrome mediates light-dependent magnetosensitivity of Drosophila's circadian clock.

    Directory of Open Access Journals (Sweden)

    Taishi Yoshii

    2009-04-01

    Full Text Available Since 1960, magnetic fields have been discussed as Zeitgebers for circadian clocks, but the mechanism by which clocks perceive and process magnetic information has remained unknown. Recently, the radical-pair model involving light-activated photoreceptors as magnetic field sensors has gained considerable support, and the blue-light photoreceptor cryptochrome (CRY has been proposed as a suitable molecule to mediate such magnetosensitivity. Since CRY is expressed in the circadian clock neurons and acts as a critical photoreceptor of Drosophila's clock, we aimed to test the role of CRY in magnetosensitivity of the circadian clock. In response to light, CRY causes slowing of the clock, ultimately leading to arrhythmic behavior. We expected that in the presence of applied magnetic fields, the impact of CRY on clock rhythmicity should be altered. Furthermore, according to the radical-pair hypothesis this response should be dependent on wavelength and on the field strength applied. We tested the effect of applied static magnetic fields on the circadian clock and found that flies exposed to these fields indeed showed enhanced slowing of clock rhythms. This effect was maximal at 300 muT, and reduced at both higher and lower field strengths. Clock response to magnetic fields was present in blue light, but absent under red-light illumination, which does not activate CRY. Furthermore, cry(b and cry(OUT mutants did not show any response, and flies overexpressing CRY in the clock neurons exhibited an enhanced response to the field. We conclude that Drosophila's circadian clock is sensitive to magnetic fields and that this sensitivity depends on light activation of CRY and on the applied field strength, consistent with the radical pair mechanism. CRY is widespread throughout biological systems and has been suggested as receptor for magnetic compass orientation in migratory birds. The present data establish the circadian clock of Drosophila as a model system

  20. Exploring interactions between pathogens and the Drosophila gut.

    Science.gov (United States)

    Mistry, Rupal; Kounatidis, Ilias; Ligoxygakis, Petros

    2016-11-01

    Gastrointestinal infection can provoke substantial disturbance at both a local as well as at a systemic level and may evolve into a chronic disease state. Our growing knowledge of gut-pathogen interactions has been based to a large extent on the use of genetically tractable model hosts such as the fruit fly Drosophila melanogaster. In this review we will summarise the growing literature and critically address the advantages and disadvantages of using this model to extrapolate results from studying pathogen virulence and intestinal responses to humans. PMID:26876781