drosophila iap1 determines: Topics by WorldWideScience.org

Sample records for drosophila iap1 determines

Functional analysis of the Autographa californica nucleopolyhedrovirus IAP1 and IAP2

NARCIS (Netherlands)

Zeng, X.D.; Nan, F.; Liang, Ch.Y.; Song, J.H.; Wang, Q.; Vlak, J.M.; Chen, X.W.

2009-01-01

The Autographa californica nucleopolyhedrovirus (AcMNPV) contains three apoptosis suppressor genes: p35, iap1 and iap2. AcMNPV P35 functions as a pancaspase inhibitor, but the function of IAP1 and IAP2 has not been entirely resolved. In this paper, we analyze the function of IAP1 and IAP2 in detail.
The HIV-1 Vpu protein induces apoptosis in Drosophila via activation of JNK signaling.

Directory of Open Access Journals (Sweden)

Christelle Marchal

Full Text Available The genome of the human immunodeficiency virus type 1 (HIV-1 encodes the canonical retroviral proteins, as well as additional accessory proteins that enhance the expression of viral genes, the infectivity of the virus and the production of virions. The accessory Viral Protein U (Vpu, in particular, enhances viral particle production, while also promoting apoptosis of HIV-infected human T lymphocytes. Some Vpu effects rely on its interaction with the ubiquitin-proteasome protein degradation system, but the mechanisms responsible for its pro-apoptotic effects in vivo are complex and remain largely to be elucidated.We took advantage of the Drosophila model to study the effects of Vpu activity in vivo. Expression of Vpu in the developing Drosophila wing provoked tissue loss due to caspase-dependent apoptosis. Moreover, Vpu induced expression of the pro-apoptotic gene reaper, known to down-regulate Inhibitor of Apoptosis Proteins (IAPs which are caspase-antagonizing E3 ubiquitin ligases. Indeed, Vpu also reduced accumulation of Drosophila IAP1 (DIAP1. Though our results demonstrate a physical interaction between Vpu and the proteasome-addressing SLIMB/β-TrCP protein, as in mammals, both SLIMB/βTrCP-dependent and -independent Vpu effects were observed in the Drosophila wing. Lastly, the pro-apoptotic effect of Vpu in this tissue was abrogated upon inactivation of the c-Jun N-terminal Kinase (JNK pathway. Our results in the fly thus provide the first functional evidence linking Vpu pro-apoptotic effects to activation of the conserved JNK pathway.
Effects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation.

LENUS (Irish Health Repository)

Gill, Catherine

2009-01-01

BACKGROUND: Manipulating apoptotic resistance represents an important strategy for the treatment of hormone refractory prostate cancer. We hypothesised that the Inhibitor of Apoptosis (IAP) Proteins may be mediating this resistance and knockdown of cIAP-1, cIAP-2 and XIAP would increase sensitivity to apoptosis. METHODS: cIAP-1, cIAP-2 and XIAP where knocked down either individually or in combination using siRNA in androgen independent prostate cancer PC-3 cells as confirmed by real-time PCR and western blotting. Cells were then treated with TRAIL, Etoposide, or Tunicamycin, and apoptosis assessed by PI DNA staining. Apoptosis was confirmed with Annexin V labelling and measurement of PARP cleavage, and was inhibited using the pan-caspase inhibitor, zVAD.fmk. Clonogenic assays and assessment of ID-1 expression by western blotting were used to measure recovery and proliferation. RESULTS: PC-3 are resistant to TRAIL induced apoptosis and have elevated expression of cIAP-1, cIAP-2 and XIAP. Combined knockdown sensitised PC-3 to TRAIL induced apoptosis, but not to Etoposide or Tunicmycin, with corresponding increases in caspase activity and PARP cleavage which was inhibited by ZVAD.fmk. Triple knock down decreased proliferation which was confirmed by decreased ID-1 expression. CONCLUSION: Simultaneous knock down of the IAPs not only sensitised the PC-3 to TRAIL but also inhibited their proliferation rates and clonogenic survival. The inability to alter sensitivity to other triggers of apoptosis suggests that this effect is specific for death receptor pathways and knock down might facilitate immune-surveillance mechanisms to counter cancer progression and, in combination with therapeutic approaches using TRAIL, could represent an important treatment strategy.
Effects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation

Directory of Open Access Journals (Sweden)

Dowling Catherine

2009-06-01

Full Text Available Abstract Background Manipulating apoptotic resistance represents an important strategy for the treatment of hormone refractory prostate cancer. We hypothesised that the Inhibitor of Apoptosis (IAP Proteins may be mediating this resistance and knockdown of cIAP-1, cIAP-2 and XIAP would increase sensitivity to apoptosis. Methods cIAP-1, cIAP-2 and XIAP where knocked down either individually or in combination using siRNA in androgen independent prostate cancer PC-3 cells as confirmed by real-time PCR and western blotting. Cells were then treated with TRAIL, Etoposide, or Tunicamycin, and apoptosis assessed by PI DNA staining. Apoptosis was confirmed with Annexin V labelling and measurement of PARP cleavage, and was inhibited using the pan-caspase inhibitor, zVAD.fmk. Clonogenic assays and assessment of ID-1 expression by western blotting were used to measure recovery and proliferation. Results PC-3 are resistant to TRAIL induced apoptosis and have elevated expression of cIAP-1, cIAP-2 and XIAP. Combined knockdown sensitised PC-3 to TRAIL induced apoptosis, but not to Etoposide or Tunicmycin, with corresponding increases in caspase activity and PARP cleavage which was inhibited by ZVAD.fmk. Triple knock down decreased proliferation which was confirmed by decreased ID-1 expression. Conclusion Simultaneous knock down of the IAPs not only sensitised the PC-3 to TRAIL but also inhibited their proliferation rates and clonogenic survival. The inability to alter sensitivity to other triggers of apoptosis suggests that this effect is specific for death receptor pathways and knock down might facilitate immune-surveillance mechanisms to counter cancer progression and, in combination with therapeutic approaches using TRAIL, could represent an important treatment strategy.
Loss of cIAP1 attenuates soleus muscle pathology and improves diaphragm function in mdx mice

Science.gov (United States)

Enwere, Emeka K.; Boudreault, Louise; Holbrook, Janelle; Timusk, Kristen; Earl, Nathalie; LaCasse, Eric; Renaud, Jean-Marc; Korneluk, Robert G.

2013-01-01

The cellular inhibitor of apoptosis 1 (cIAP1) protein is an essential regulator of canonical and noncanonical nuclear factor κB (NF-κB) signaling pathways. NF-κB signaling is known to play important roles in myogenesis and degenerative muscle disorders such as Duchenne muscular dystrophy (DMD), but the involvement of cIAP1 in muscle disease has not been studied directly. Here, we asked whether the loss of cIAP1 would influence the pathology of skeletal muscle in the mdx mouse model of DMD. Double-mutant cIAP1−/−;mdx mice exhibited reduced muscle damage and decreased fiber centronucleation in the soleus, compared with single-mutant cIAP1+/+;mdx mice. This improvement in pathology was associated with a reduction in muscle infiltration by macrophages and diminished expression of inflammatory cytokines such as IL-6 and tumor necrosis factor-α. Furthermore, the cIAP1−/−;mdx mice exhibited reduced serum creatine kinase, and improved exercise endurance associated with improved exercise resilience by the diaphragm. Mechanistically, the loss of cIAP1 was sufficient to drive constitutive activation of the noncanonical NF-κB pathway, which led to increased myoblast fusion in vitro and in vivo. Collectively, these results show that the loss of cIAP1 protects skeletal muscle from the degenerative pathology resulting from systemic loss of dystrophin. PMID:23184147
Structures of BIR domains from human NAIP and cIAP2

International Nuclear Information System (INIS)

Herman, Maria Dolores; Moche, Martin; Flodin, Susanne; Welin, Martin; Trésaugues, Lionel; Johansson, Ida; Nilsson, Martina; Nordlund, Pär; Nyman, Tomas

2009-01-01

The crystal structures of the human NAIP BIR2 and cIAP2 BIR3 domains have been determined. Both BIR domains harbors an amino-terminal tetrapeptide in its peptide-binding groove. The inhibitor of apoptosis (IAP) family of proteins contains key modulators of apoptosis and inflammation that interact with caspases through baculovirus IAP-repeat (BIR) domains. Overexpression of IAP proteins frequently occurs in cancer cells, thus counteracting the activated apoptotic program. The IAP proteins have therefore emerged as promising targets for cancer therapy. In this work, X-ray crystallography was used to determine the first structures of BIR domains from human NAIP and cIAP2. Both structures harbour an N-terminal tetrapeptide in the conserved peptide-binding groove. The structures reveal that these two proteins bind the tetrapeptides in a similar mode as do other BIR domains. Detailed interactions are described for the P1′–P4′ side chains of the peptide, providing a structural basis for peptide-specific recognition. An arginine side chain in the P3′ position reveals favourable interactions with its hydrophobic moiety in the binding pocket, while hydrophobic residues in the P2′ and P4′ pockets make similar interactions to those seen in other BIR domain–peptide complexes. The structures also reveal how a serine in the P1′ position is accommodated in the binding pockets of NAIP and cIAP2. In addition to shedding light on the specificity determinants of these two proteins, the structures should now also provide a framework for future structure-based work targeting these proteins
A novel inhibitor of apoptosis protein (IAP)-interacting protein, Vestigial-like (Vgl)-4, counteracts apoptosis-inhibitory function of IAPs by nuclear sequestration

International Nuclear Information System (INIS)

Jin, Hyung-Seung; Park, Hyung-Sun; Shin, Jun-Ha; Kim, Dong-Hwan; Jun, Sung-Hun; Lee, Chang-Jun; Lee, Tae H.

2011-01-01

Highlights: → We identified a new IAP binding protein Vgl-4. → Vgl-4 is expressed mainly in the nucleus and triggers a relocalization of IAPs from the cytoplasm to the nucleus. → Vgl-4-mediated IAP nuclear localization was blocked by TRAF2 coexpression. → Vgl-4 suppresses the ability of IAPs to prevent cell death, however TRAF2 can revere the effect of Vgl-4. → Vgl-4 functions as an IAP regulator by binding to IAPs and altering their sub-cellular localization. -- Abstract: The inhibitors of apoptosis proteins (IAP), which include cIAP1, cIAP2 and XIAP, suppress apoptosis through the inhibition of caspases, and the activity of IAPs is regulated by a variety of IAP-binding proteins. Herein, we report the identification of a Vestigial-like 4 (Vgl-4), which functions as a transcription cofactor in cardiac myocytes, as a new IAP binding protein. Vgl-4 is expressed predominantly in the nucleus and its overexpression triggers a relocalization of IAPs from the cytoplasm to the nucleus. cIAP1/2-interacting protein TRAF2 (TNF receptor-associated factor 2) prevented the Vgl-4-driven nuclear localization of cIAP2. Accordingly, the forced relocation of IAPs to the nucleus by Vgl-4 significantly reduced their ability to prevent Bax- and TNFα-induced apoptosis, which can be recovered by co-expression with TRAF2. Our results suggest that Vgl-4 may play a role in the apoptotic pathways by regulating translocation of IAPs between different cell compartments.
Structures of BIR domains from human NAIP and cIAP2.

Science.gov (United States)

Herman, Maria Dolores; Moche, Martin; Flodin, Susanne; Welin, Martin; Trésaugues, Lionel; Johansson, Ida; Nilsson, Martina; Nordlund, Pär; Nyman, Tomas

2009-11-01

The inhibitor of apoptosis (IAP) family of proteins contains key modulators of apoptosis and inflammation that interact with caspases through baculovirus IAP-repeat (BIR) domains. Overexpression of IAP proteins frequently occurs in cancer cells, thus counteracting the activated apoptotic program. The IAP proteins have therefore emerged as promising targets for cancer therapy. In this work, X-ray crystallography was used to determine the first structures of BIR domains from human NAIP and cIAP2. Both structures harbour an N-terminal tetrapeptide in the conserved peptide-binding groove. The structures reveal that these two proteins bind the tetrapeptides in a similar mode as do other BIR domains. Detailed interactions are described for the P1'-P4' side chains of the peptide, providing a structural basis for peptide-specific recognition. An arginine side chain in the P3' position reveals favourable interactions with its hydrophobic moiety in the binding pocket, while hydrophobic residues in the P2' and P4' pockets make similar interactions to those seen in other BIR domain-peptide complexes. The structures also reveal how a serine in the P1' position is accommodated in the binding pockets of NAIP and cIAP2. In addition to shedding light on the specificity determinants of these two proteins, the structures should now also provide a framework for future structure-based work targeting these proteins.
Dnmt1 Expression in Pre- and Postimplantation Embryogenesis and the Maintenance of IAP Silencing

Science.gov (United States)

Gaudet, F.; Rideout, W. M.; Meissner, A.; Dausman, J.; Leonhardt, H.; Jaenisch, R.

2004-01-01

The methylation of intracisternal A-type particle (IAP) sequences is maintained during mouse embryogenesis. Methylation suppresses IAP expression and the potential for mutagenesis by retrotransposition, but it is not clear how methylation of these elements is maintained during the embryonic stages when the bulk of the genome is being demethylated. It has been suggested that the high levels of DNA methyltransferase-1 (Dnmt1) present during cleavage could be important for keeping IAPs methylated. To test this hypothesis, we combined mutant alleles of Dnmt1 with an agouti allele (Aiapy), which provided a coat color readout for the methylation status of the IAP insertion in the agouti locus. We found that reduction in Dnmt1 levels directly impacted methylation at this locus, leading to stable transcriptional activation of the agouti gene in the adult. Specifically, the short maternal Dnmt1 protein was important in maintaining methylation at the Aiapy locus in cleavage embryos, whereas the longer Dnmt1 isoform found in somatic cells was important in maintaining IAP methylation during the postimplantation stage. These results underscore the importance of maintaining proper maintenance of methylation patterns during gestation and suggest that interference with this process may stably affect gene expression patterns in the adult and may have profound phenotypic consequences. PMID:14749379
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.
IAPs Regulate Distinct Innate Immune Pathways to Co-ordinate the Response to Bacterial Peptidoglycans.

Science.gov (United States)

Stafford, Che A; Lawlor, Kate E; Heim, Valentin J; Bankovacki, Aleksandra; Bernardini, Jonathan P; Silke, John; Nachbur, Ueli

2018-02-06

Inhibitors of apoptosis (IAPs) proteins are critical regulators of innate immune signaling pathways and therefore have potential as drug targets. X-linked IAP (XIAP) and cellular IAP1 and IAP2 (cIAP1 and cIAP2) are E3 ligases that have been shown to be required for signaling downstream of NOD2, an intracellular receptor for bacterial peptidoglycan. We used genetic and biochemical approaches to compare the responses of IAP-deficient mice and cells to NOD2 stimulation. In all cell types tested, XIAP is the only IAP required for signaling immediately downstream of NOD2, while cIAP1 and cIAP2 are dispensable for NOD2-induced nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) activation. However, mice lacking cIAP1 or TNFR1 have a blunted cytokine response to NOD2 stimulation. We conclude that cIAPs regulate NOD2-dependent autocrine TNF signaling in vivo and highlight the importance of physiological context in the interplay of innate immune signaling pathways. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.
Inhibitors of apoptosis (IAPs) regulate intestinal immunity and inflammatory bowel disease (IBD) inflammation

DEFF Research Database (Denmark)

Pedersen, Jannie; LaCasse, Eric C; Seidelin, Jakob B

2014-01-01

The inhibitor of apoptosis (IAP) family members, notably cIAP1, cIAP2, and XIAP, are critical and universal regulators of tumor necrosis factor (TNF) mediated survival, inflammatory, and death signaling pathways. Furthermore, IAPs mediate the signaling of nucleotide-binding oligomerization domain...
Upregulation of cIAP2 in regenerating colonocytes in ulcerative colitis

DEFF Research Database (Denmark)

Seidelin, J.B.; Vainer, Ben; Andresen, L.

2007-01-01

of cIAP2 in active UC was therefore investigated. Fourteen patients with active UC and 12 control subjects who underwent routine colonoscopy for control of their disease or as part of their examination program for irritable bowel syndrome were included. cIAP1 and cIAP2 expression was investigated...
Design, synthesis, and biological activities of novel hexahydropyrazino[1,2-a]indole derivatives as potent inhibitors of apoptosis (IAP) proteins antagonists with improved membrane permeability across MDR1 expressing cells.

Science.gov (United States)

Shiokawa, Zenyu; Hashimoto, Kentaro; Saito, Bunnai; Oguro, Yuya; Sumi, Hiroyuki; Yabuki, Masato; Yoshimatsu, Mie; Kosugi, Yohei; Debori, Yasuyuki; Morishita, Nao; Dougan, Douglas R; Snell, Gyorgy P; Yoshida, Sei; Ishikawa, Tomoyasu

2013-12-15

We previously reported octahydropyrrolo[1,2-a]pyrazine derivative 2 (T-3256336) as a potent antagonist for inhibitors of apoptosis (IAP) proteins. Because compound 2 was susceptible to MDR1 mediated efflux, we developed another scaffold, hexahydropyrazino[1,2-a]indole, using structure-based drug design. The fused benzene ring of this scaffold was aimed at increasing the lipophilicity and decreasing the basicity of the scaffold to improve the membrane permeability across MDR1 expressing cells. We established a chiral pool synthetic route to yield the desired tricyclic chiral isomers. Chemical modification of the core scaffold led to a representative compound 50, which showed strong inhibition of IAP binding (X chromosome-linked IAP [XIAP]: IC50 23 nM and cellular IAP [cIAP]: IC50 1.1 nM) and cell growth inhibition (MDA-MB-231 cells: GI50 2.8 nM) with high permeability and low potential of MDR1 substrate. Copyright © 2013 Elsevier Ltd. All rights reserved.
Overcoming chemotherapy drug resistance by targeting inhibitors of apoptosis proteins (IAPs).

Science.gov (United States)

Rathore, Rama; McCallum, Jennifer E; Varghese, Elizabeth; Florea, Ana-Maria; Büsselberg, Dietrich

2017-07-01

Inhibitors of apoptosis (IAPs) are a family of proteins that play a significant role in the control of programmed cell death (PCD). PCD is essential to maintain healthy cell turnover within tissue but also to fight disease or infection. Uninhibited, IAPs can suppress apoptosis and promote cell cycle progression. Therefore, it is unsurprising that cancer cells demonstrate significantly elevated expression levels of IAPs, resulting in improved cell survival, enhanced tumor growth and subsequent metastasis. Therapies to target IAPs in cancer has garnered substantial scientific interest and as resistance to anti-cancer agents becomes more prevalent, targeting IAPs has become an increasingly attractive strategy to re-sensitize cancer cells to chemotherapies, antibody based-therapies and TRAIL therapy. Antagonism strategies to modulate the actions of XIAP, cIAP1/2 and survivin are the central focus of current research and this review highlights advances within this field with particular emphasis upon the development and specificity of second mitochondria-derived activator of caspase (SMAC) mimetics (synthetic analogs of endogenously expressed inhibitors of IAPs SMAC/DIABLO). While we highlight the potential of SMAC mimetics as effective single agent or combinatory therapies to treat cancer we also discuss the likely clinical implications of resistance to SMAC mimetic therapy, occasionally observed in cancer cell lines.
A Smac-mimetic sensitizes prostate cancer cells to TRAIL-induced apoptosis via modulating both IAPs and NF-kappaB

International Nuclear Information System (INIS)

Dai, Yao; Liu, Meilan; Tang, Wenhua; Li, Yongming; Lian, Jiqin; Lawrence, Theodore S; Xu, Liang

2009-01-01

Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for human cancer therapy, prostate cancer still remains resistant to TRAIL. Both X-linked inhibitor of apoptosis (XIAP) and nuclear factor-kappaB function as key negative regulators of TRAIL signaling. In this study, we evaluated the effect of SH122, a small molecule mimetic of the second mitochondria-derived activator of caspases (Smac), on TRAIL-induced apoptosis in prostate cancer cells. The potential of Smac-mimetics to bind XIAP or cIAP-1 was examined by pull-down assay. Cytotoxicity of TRAIL and/or Smac-mimetics was determined by a standard cell growth assay. Silencing of XIAP or cIAP-1 was achieved by transient transfection of short hairpin RNA. Apoptosis was detected by Annexin V-PI staining followed by flow cytometry and by Western Blot analysis of caspases, PARP and Bid. NF-kappaB activation was determined by subcellular fractionation, real time RT-PCR and reporter assay. SH122, but not its inactive analog, binds to XIAP and cIAP-1. SH122 significantly sensitized prostate cancer cells to TRAIL-mediated cell death. Moreover, SH122 enhanced TRAIL-induced apoptosis via both the death receptor and the mitochondrial pathway. Knockdown of both XIAP and cIAP-1 sensitized cellular response to TRAIL. XIAP-knockdown attenuated sensitivity of SH122 to TRAIL-induced cytotoxicity, confirming that XIAP is an important target for IAP-inhibitor-mediated TRAIL sensitization. SH122 also suppressed TRAIL-induced NF-kappaB activation by preventing cytosolic IkappaB-alpha degradation and RelA nuclear translocation, as well as by suppressing NF-kappaB target gene expression. These results demonstrate that SH122 sensitizes human prostate cancer cells to TRAIL-induced apoptosis by mimicking Smac and blocking both IAPs and NF-kappaB. Modulating IAPs may represent a promising approach to overcoming TRAIL-resistance in human prostate cancer with constitutively active NF-kappaB signaling
Connective tissue growth factor confers drug resistance in breast cancer through concomitant up-regulation of Bcl-xL and cIAP1.

Science.gov (United States)

Wang, Ming-Yang; Chen, Pai-Sheng; Prakash, Ekambaranellore; Hsu, Hsing-Chih; Huang, Hsin-Yi; Lin, Ming-Tsan; Chang, King-Jen; Kuo, Min-Liang

2009-04-15

Connective tissue growth factor (CTGF) expression is elevated in advanced breast cancer and promotes metastasis. Chemotherapy response is only transient in most metastatic diseases. In the present study, we examined whether CTGF expression could confer drug resistance in human breast cancer. In breast cancer patients who received neoadjuvant chemotherapy, CTGF expression was inversely associated with chemotherapy response. Overexpression of CTGF in MCF7 cells (MCF7/CTGF) enhanced clonogenic ability, cell viability, and resistance to apoptosis on exposure to doxorubicin and paclitaxel. Reducing the CTGF level in MDA-MB-231 (MDA231) cells by antisense CTGF cDNA (MDA231/AS cells) mitigated this drug resistance capacity. CTGF overexpression resulted in resistance to doxorubicin- and paclitaxel-induced apoptosis by up-regulation of Bcl-xL and cellular inhibitor of apoptosis protein 1 (cIAP1). Knockdown of Bcl-xL or cIAP1 with specific small interfering RNAs abolished the CTGF-mediated resistance to apoptosis induced by the chemotherapeutic agents in MCF7/CTGF cells. Inhibition of extracellular signal-regulated kinase (ERK)-1/2 effectively reversed the resistance to apoptosis as well as the up-regulation of Bcl-xL and cIAP1 in MCF7/CTGF cells. A neutralizing antibody against integrin alpha(v)beta(3) significantly attenuated CTGF-mediated ERK1/2 activation and up-regulation of Bcl-xL and cIAP1, indicating that the integrin alpha(v)beta(3)/ERK1/2 signaling pathway is essential for CTGF functions. The Bcl-xL level also correlated with the CTGF level in breast cancer patients. We also found that a COOH-terminal domain peptide from CTGF could exert activities similar to full-length CTGF, in activation of ERK1/2, up-regulation of Bcl-xL/cIAP1, and resistance to apoptosis. We conclude that CTGF expression could confer resistance to chemotherapeutic agents through augmenting a survival pathway through ERK1/2-dependent Bcl-xL/cIAP1 up-regulation.
Targeting IAP proteins in combination with radiotherapy

International Nuclear Information System (INIS)

Fulda, Simone

2015-01-01

The efficacy of radiotherapy critically depends on the activation of intrinsic cell death programs in cancer cells. This implies that evasion of cell death, a hallmark of human cancers, can contribute to radioresistance. Therefore, novel strategies to reactivate cell death programs in cancer cells are required in order to overcome resistance to radiotherapy. Since Inhibitor of Apoptosis (IAP) proteins are expressed at high levels in multiple cancers and block cell death induction at a central point, therapeutic targeting of IAP proteins represents a promising approach to potentiate the efficacy of radiotherapy. The current review discusses the concept of targeting IAP proteins in combination with radiotherapy
IAPs contain an evolutionarily conserved ubiquitin-binding domain that regulates NF-kappaB as well as cell survival and oncogenesis

DEFF Research Database (Denmark)

Gyrd-Hansen, Mads; Darding, Maurice; Miasari, Maria

2008-01-01

found that the UBA domain is essential for the oncogenic potential of cIAP1, to maintain endothelial cell survival and to protect cells from TNF-alpha-induced apoptosis. Moreover, the UBA domain is required for XIAP and cIAP2-MALT1 to activate NF-kappaB. Our data suggest that the UBA domain of cIAP2......-MALT1 stimulates NF-kappaB signalling by binding to polyubiquitylated NEMO. Significantly, 98% of all cIAP2-MALT1 fusion proteins retain the UBA domain, suggesting that ubiquitin-binding contributes to the oncogenic potential of cIAP2-MALT1 in MALT lymphoma. Our data identify IAPs as ubiquitin...
A novel role for inhibitor of apoptosis (IAP) proteins as regulators of endothelial barrier function by mediating RhoA activation.

Science.gov (United States)

Hornburger, Michael C; Mayer, Bettina A; Leonhardt, Stefanie; Willer, Elisabeth A; Zahler, Stefan; Beyerle, Andrea; Rajalingam, Krishnaraj; Vollmar, Angelika M; Fürst, Robert

2014-04-01

Inhibitor of apoptosis (IAP) proteins, such as XIAP or cIAP1/2, are important regulators of apoptosis in cancer cells, and IAP antagonists are currently evaluated as antitumor agents. Beyond their function in cancer cells, this study demonstrates a novel role of IAPs as regulators of vascular endothelial permeability. Two structurally different IAP antagonists, ABT and Smac085, as well as silencing of IAPs, reduced the thrombin receptor-activating peptide (TRAP)-induced barrier dysfunction in human endothelial cells as assessed by measuring macromolecular permeability or transendothelial electrical resistance. ABT diminished thrombin-evoked stress fiber formation, activation of myosin light chain 2, and disassembly of adherens junctions independent of calcium signaling, protein kinase C, and mitogen-activated protein kinases. Interestingly, ABT and silencing of IAPs, in particular XIAP, reduced the TRAP-evoked RhoA activation, whereas Rac1 was not affected. XIAP and, to a lesser extent, cIAP1 were found to directly interact with RhoA independently of the RhoA activation status. Under cell-free conditions, XIAP did not induce an ubiquitination of RhoA. In summary, our work discloses IAPs as crucial regulators of endothelial permeability and suggests IAP inhibition as interesting approach for the prevention of endothelial barrier dysfunction.

Adaptation of the International Affective Picture System (IAPS) for European Portuguese.

Science.gov (United States)

Soares, Ana Paula; Pinheiro, Ana P; Costa, Ana; Frade, Carla Sofia; Comesaña, Montserrat; Pureza, Rita

2015-12-01

This study presents the results of the adaptation of the International Affective Picture System (IAPS) for European Portuguese (EP). Following the original procedure of Lang et al., 2000 native speakers of EP rated the 1,182 pictures of the last version of the IAPS set on the three affective dimensions of valence, arousal, and dominance, using the Self-Assessment Manikin (SAM). Results showed that the normative values of the IAPS for EP are properly distributed in the affective space of valence and arousal, showing the typical boomerang-shaped distribution observed in previous studies. Results also point to important differences in the way Portuguese females and males react to affective pictures that should be taken into consideration when planning and conducting research with Portuguese samples. Furthermore, the results from the cross-cultural comparisons between the EP ratings and the ratings from the American, Spanish, Brazilian, Belgian, Chilean, Indian, and Bosnian-Herzegovinian standardizations, showed that in spite of the fact that IAPS stimuli elicited affective responses that are similar across countries and cultures (at least in Western cultures), there are differences in the way Portuguese individuals react to IAPS pictures that strongly recommend the use of the normative values presented in this work. They can be downloaded as a supplemental archive at http://brm.psychonomic-journals.org/content/supplemental or at http://p-pal.di.uminho.pt/about/databases.
Poly(I:C) induces intense expression of c-IAP2 and cooperates with an IAP inhibitor in induction of apoptosis in cancer cells

International Nuclear Information System (INIS)

Friboulet, Luc; Gourzones, Claire; Tsao, Sai Wah; Morel, Yannis; Paturel, Carine; Témam, Stéphane; Uzan, Catherine; Busson, Pierre

2010-01-01

There is increasing evidence that the toll-like receptor 3 (TLR3) is an interesting target for anti-cancer therapy. Unfortunately, most laboratory investigations about the impact of TLR3 stimulation on human malignant cells have been performed with very high concentrations - 5 to 100 μg/ml - of the prototype TLR3 ligand, poly(I:C). In a previous study focused on a specific type of human carcinoma - nasopharyngeal carcinoma - we have shown that concentrations of poly(I:C) as low as 100 ng/ml are sufficient to induce apoptosis of malignant cells when combined to a pharmacological antagonist of the IAP family based on Smac mimicry. This observation prompted us to investigate the contribution of the IAP family in cell response to poly(I:C) in a variety of human malignant cell types. We report a rapid, intense and selective increase in c-IAP2 protein expression observed under stimulation by poly(I:C)(500 ng/ml) in all types of human malignant cells. In most cell types, this change in protein expression is underlain by an increase in c-IAP2 transcripts and dependent on the TLR3/TRIF pathway. When poly(I:C) is combined to the IAP inhibitor RMT 5265, a cooperative effect in apoptosis induction and/or inhibition of clonogenic growth is obtained in a large fraction of carcinoma and melanoma cell lines. Currently, IAP inhibitors like RMT 5265 and poly(I:C) are the subject of separate therapeutic trials. In light of our observations, combined use of both types of compounds should be considered for treatment of human malignancies including carcinomas and melanomas
AT-406, an IAP inhibitor, activates apoptosis and induces radiosensitization of normoxic and hypoxic cervical cancer cells.

Science.gov (United States)

Lu, Jing; Qin, Qin; Zhan, Liang-Liang; Liu, Jia; Zhu, Hong-Cheng; Yang, Xi; Zhang, Chi; Xu, Li-Ping; Liu, Zhe-Ming; Wang, Di; Cui, He-Qing; Meng, Ciu-Ciu; Cai, Jing; Cheng, Hong-Yan; Sun, Xin-Chen

2014-01-01

IAP antagonists increased the antitumor efficacy of X-irradiation in some types of cancers, but their effects on hypoxic cancer cells remain unclarified. We aims to investigate the radiosensitizing effect of an IAP inhibitor AT-406 on cervical cancer cell lines under both normoxia and hypoxia conditions. Hela and Siha cells were treated to investigate the effects of drug administration on cell proliferation, apoptosis, and radiosensitivity. Western blot analysis was used to determine the role of AT-406 in inhibition of IAPs. The pathway of apoptosis was characterized by caspases activity assay. AT-406 potently sensitized Hela cells but not Siha cells to radiation under normoxia. Notably, the radiosensitizing effect of AT-406 on hypoxic cells was more evident than on normoxic cells in both cell lines. Further mechanism studies by western blot showed that under normoxia AT-406 decreased the level of cIAP1 in Hela cells in a dose-dependent manner; while additional downregulation of XIAP expression was induced by AT-406 treatment under hypoxia in both cell lines. Finally, AT-406 works on both extrinsic death receptor and intrinsic mitochondrial apoptosis pathways to activate apoptosis. Totally, AT-406 acts as a strong radiosensitizer in human cervical cancer cells, especially in hypoxic condition.
Role of IAPs in prostate cancer progression: immunohistochemical study in normal and pathological (benign hyperplastic, prostatic intraepithelial neoplasia and cancer) human prostate

International Nuclear Information System (INIS)

Rodríguez-Berriguete, Gonzalo; Paniagua, Ricardo; Royuela, Mar; Fraile, Benito; Bethencourt, Fermín R de; Prieto-Folgado, Angela; Bartolome, Nahikari; Nuñez, Claudia; Prati, Bruna; Martínez-Onsurbe, Pilar; Olmedilla, Gabriel

2010-01-01

In this study was investigate IAPs in normal human prostate (NP), benign prostatic hyperplasia (BPH), prostatic intraepithelial neoplasia (PIN) and prostatic carcinoma (PC), and their involvement in apoptosis/proliferation via NF-kB (TNF-α, IL-1) stimulation. Immunohistochemical and Western blot analyses were performed in 10 samples of normal prostates, 35 samples of BPH, 27 samples diagnosis of PIN (with low-grade PIN or high-grade PIN) and 95 samples of PC (with low, medium or high Gleason grades). In NP, cytoplasm of epithelial cells were positive to c-IAP1/2 (80% of samples), c-IAP-2 (60%), ILP (20%), XIAP (20%); negative to NAIP and survivin. In BPH, epithelial cells were immunostained to c-IAP1/2 (57.57%), c-IAP-2 (57.57%), ILP (66.6%), NAIP (60.6%), XIAP (27.27%), survivin (9.1%). Whereas low-grade PIN showed intermediate results between NP and BPH; results in high-grade PIN were similar to those found in PC. In PC, epithelial cells were immunostained to c-IAP1/2, c-IAP-2, ILP, NAIP, XIAP (no Gleason variation) and survivin (increasing with Gleason). IAPs could be involved in prostate disorder (BPH, PIN and PC) development since might be provoke inhibition of apoptosis and subsequently cell proliferation. At the same time, different transduction pathway such as IL-1/NIK/NF-kB or TNF/NF-kB (NIK or p38) also promotes proliferation. Inhibitions of IAPs, IL-1α and TNFα might be a possible target for PC treatment since IAPs are the proteins that inhibited apoptosis (favour proliferation) and IL-1α and TNFα would affect all the transduction pathway involucrate in the activation of transcription factors related to survival or proliferation (NF-kB, Elk-1 or ATF-2)
The small-molecule IAP antagonist AT406 inhibits pancreatic cancer cells in vitro and in vivo

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yongsheng; Meng, Qinghua [Department of General Surgery, Jinan Central Hospital of Shandong University, Jinan (China); Chen, Bo [Department of Biliary and Pancreatic Surgery, East Hospital Affiliated to Tongji University in Shanghai, Shanghai (China); Shen, Haiyu; Yan, Bing [Department of General Surgery, Jinan Central Hospital of Shandong University, Jinan (China); Sun, Baoyou, E-mail: sunbaoyou_sdu@yeah.net [Department of General Surgery, Shandong Provincial Hospital Affiliated to Shandong University, No.9677 Jing-Shi Road, Jinan 250014 (China)

2016-09-09

In the present study, we tested the anti-pancreatic cancer activity by AT406, a small-molecule antagonist of IAP (inhibitor of apoptosis proteins). In established (Panc-1 and Mia-PaCa-2 lines) and primary human pancreatic cancer cells, treatment of AT406 significantly inhibited cell survival and proliferation. Yet, same AT406 treatment was non-cytotoxic to pancreatic epithelial HPDE6c7 cells. AT406 increased caspase-3/-9 activity and provoked apoptosis in the pancreatic cancer cells. Reversely, AT406′ cytotoxicity in these cells was largely attenuated with pre-treatment of caspase inhibitors. AT406 treatment caused degradation of IAP family proteins (cIAP1 and XIAP) and release of cytochrome C, leaving Bcl-2 unaffected in pancreatic cancer cells. Bcl-2 inhibition (by ABT-737) or shRNA knockdown dramatically sensitized Panc-1 cells to AT406. In vivo, oral administration of AT406 at well-tolerated doses downregulated IAPs (cIAP1/XIAP) and inhibited Panc-1 xenograft tumor growth in severe combined immunodeficient (SCID) nude mice. Together, our preclinical results suggest that AT406 could be further evaluated as a promising anti-pancreatic cancer agent. - Highlights: • AT406 is cytotoxic to established/primary human pancreatic cancer cells. • AT406 provokes caspase-dependent apoptosis in pancreatic cancer cells. • AT406 causes degradation of key IAPs and promotes cytochrome C release. • Bcl-2 inhibition or knockdown dramatically sensitizes Panc-1 cells to AT406. • Oral administration of AT406 inhibits Panc-1 tumor growth in SCID nude mice.
The small-molecule IAP antagonist AT406 inhibits pancreatic cancer cells in vitro and in vivo

International Nuclear Information System (INIS)

Jiang, Yongsheng; Meng, Qinghua; Chen, Bo; Shen, Haiyu; Yan, Bing; Sun, Baoyou

2016-01-01

In the present study, we tested the anti-pancreatic cancer activity by AT406, a small-molecule antagonist of IAP (inhibitor of apoptosis proteins). In established (Panc-1 and Mia-PaCa-2 lines) and primary human pancreatic cancer cells, treatment of AT406 significantly inhibited cell survival and proliferation. Yet, same AT406 treatment was non-cytotoxic to pancreatic epithelial HPDE6c7 cells. AT406 increased caspase-3/-9 activity and provoked apoptosis in the pancreatic cancer cells. Reversely, AT406′ cytotoxicity in these cells was largely attenuated with pre-treatment of caspase inhibitors. AT406 treatment caused degradation of IAP family proteins (cIAP1 and XIAP) and release of cytochrome C, leaving Bcl-2 unaffected in pancreatic cancer cells. Bcl-2 inhibition (by ABT-737) or shRNA knockdown dramatically sensitized Panc-1 cells to AT406. In vivo, oral administration of AT406 at well-tolerated doses downregulated IAPs (cIAP1/XIAP) and inhibited Panc-1 xenograft tumor growth in severe combined immunodeficient (SCID) nude mice. Together, our preclinical results suggest that AT406 could be further evaluated as a promising anti-pancreatic cancer agent. - Highlights: • AT406 is cytotoxic to established/primary human pancreatic cancer cells. • AT406 provokes caspase-dependent apoptosis in pancreatic cancer cells. • AT406 causes degradation of key IAPs and promotes cytochrome C release. • Bcl-2 inhibition or knockdown dramatically sensitizes Panc-1 cells to AT406. • Oral administration of AT406 inhibits Panc-1 tumor growth in SCID nude mice.
Cellular inhibitor of apoptosis protein 2 (cIAP2) controls human colonic epithelial restitution, migration and Rac1 activation

DEFF Research Database (Denmark)

Seidelin, JB; Larsen, Sylvester; Linnemann, D

2015-01-01

epithelial cells (IECs) was increased at the wound edge after 24 h (P 2 was induced in vitro in regenerating Caco2 IECs after wound infliction (P ...Identification of pathways involved in wound healing is important for understanding the pathogenesis of various intestinal diseases. Cellular inhibitor of apoptosis protein 2 (cIAP2) regulates proliferation and migration in nonepithelial cells and is expressed in human colonocytes. The aim...... of the study was to investigate the role of cIAP2 for wound healing in the normal human colon. Wound tissue was generated by taking rectosigmoidal biopsies across an experimental ulcer in healthy subjects after 5, 24, and 48 h. In experimental ulcers, the expression of cIAP2 in regenerating intestinal...
IAP/APA evidence-based guidelines for the management of acute pancreatitis

NARCIS (Netherlands)

Goor, H. van; et al.,

2013-01-01

BACKGROUND: There have been substantial improvements in the management of acute pancreatitis since the publication of the International Association of Pancreatology (IAP) treatment guidelines in 2002. A collaboration of the IAP and the American Pancreatic Association (APA) was undertaken to revise
IAP/APA evidence-based guidelines for the management of acute pancreatitis

NARCIS (Netherlands)

Besselink, Marc; van Santvoort, Hjalmar; Freeman, Martin; Gardner, Timothy; Mayerle, Julia; Vege, Santhi Swaroop; Werner, Jens; Banks, Peter; McKay, Colin; Fernandez-del Castillo, Carlos; French, Jeremy; Gooszen, Hein; Johnson, Colin; Sarr, Mike; Takada, Tadahiro; Windsor, John; Saluja, Ashok; Liddle, Rodger; Papachristou, Georgios; Singh, Vijay; Rünzi, Michael; Wu, Bechien; Singh, Vikesh; Bollen, Thomas; Morgan, Desiree; Mortele, Koenraad; Mittal, Anubhav; En-qiang, Mao; de Waele, Jan; Petrov, Maxim; Dellinger, Patchen; Lerch, Markus M.; Anderson, Roland; McClave, Stephen; Hartwig, Werner; Bruno, Marco; Oria, Alejandro; Baron, Todd; Castillo, Carlos Fernandez-Del; Fagenholz, Peter; Horvath, Karen; van Baal, Mark; Nealon, William; Andren-Sandberg, Ake; Bakker, Olaf; Bassi, Claudio; Buchler, Markus; Boermeester, Marja; Bradley, Ed; Fockens, Paul

2013-01-01

There have been substantial improvements in the management of acute pancreatitis since the publication of the International Association of Pancreatology (IAP) treatment guidelines in 2002. A collaboration of the IAP and the American Pancreatic Association (APA) was undertaken to revise these
IAP survivin regulates atherosclerotic macrophage survival

NARCIS (Netherlands)

Blanc-Brude, Olivier P.; Teissier, Elisabeth; Castier, Yves; Lesèche, Guy; Bijnens, Ann-Pascal; Daemen, Mat; Staels, Bart; Mallat, Ziad; Tedgui, Alain

2007-01-01

Inflammatory macrophage apoptosis is critical to atherosclerotic plaque formation, but its mechanisms remain enigmatic. We hypothesized that inhibitor of apoptosis protein (IAP) survivin regulates macrophage death in atherosclerosis. Western blot analysis revealed discrete survivin expression in
Analysis of high-throughput plant image data with the information system IAP

Directory of Open Access Journals (Sweden)

Klukas Christian

2012-06-01

Full Text Available This work presents a sophisticated information system, the Integrated Analysis Platform (IAP, an approach supporting large-scale image analysis for different species and imaging systems. In its current form, IAP supports the investigation of Maize, Barley and Arabidopsis plants based on images obtained in different spectra.
Inhibitor of apoptosis (IAP) proteins in regulation of inflammation and innate immunity

DEFF Research Database (Denmark)

Damgaard, Rune B; Gyrd-Hansen, Mads

2011-01-01

, and XIAP facilitate ubiquitin-dependent signaling activated by these PRRs and mediate activation of nuclear factor-kappa B (NF-kappaB) transcription factors as well as the MAP kinases p38 and JNK. Here, we review the current understanding of IAP-mediated PRR signaling and how IAP proteins might present...
IAP/APA evidence-based guidelines for the management of acute pancreatitis.

Science.gov (United States)

2013-01-01

There have been substantial improvements in the management of acute pancreatitis since the publication of the International Association of Pancreatology (IAP) treatment guidelines in 2002. A collaboration of the IAP and the American Pancreatic Association (APA) was undertaken to revise these guidelines using an evidence-based approach. Twelve multidisciplinary review groups performed systematic literature reviews to answer 38 predefined clinical questions. Recommendations were graded using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The review groups presented their recommendations during the 2012 joint IAP/APA meeting. At this one-day, interactive conference, relevant remarks were voiced and overall agreement on each recommendation was quantified using plenary voting. The 38 recommendations covered 12 topics related to the clinical management of acute pancreatitis: A) diagnosis of acute pancreatitis and etiology, B) prognostication/predicting severity, C) imaging, D) fluid therapy, E) intensive care management, F) preventing infectious complications, G) nutritional support, H) biliary tract management, I) indications for intervention in necrotizing pancreatitis, J) timing of intervention in necrotizing pancreatitis, K) intervention strategies in necrotizing pancreatitis, and L) timing of cholecystectomy. Using the GRADE system, 21 of the 38 (55%) recommendations, were rated as 'strong' and plenary voting revealed 'strong agreement' for 34 (89%) recommendations. The 2012 IAP/APA guidelines provide recommendations concerning key aspects of medical and surgical management of acute pancreatitis based on the currently available evidence. These recommendations should serve as a reference standard for current management and guide future clinical research on acute pancreatitis. Copyright © 2013 IAP and EPC. Published by Elsevier B.V. All rights reserved.
The SCF ubiquitin ligase Slimb controls Nerfin-1 turnover in Drosophila.

Science.gov (United States)

Lin, Xiaohui; Wang, Feng; Li, Yuanpei; Zhai, Chaojun; Wang, Guiping; Zhang, Xiaoting; Gao, Yang; Yi, Tao; Sun, Dan; Wu, Shian

2018-01-01

The C2H2 type zinc-finger transcription factor Nerfin-1 expresses dominantly in Drosophila nervous system and plays an important role in early axon guidance decisions and preventing neurons dedifferentiation. Recently, increasing reports indicated that INSM1 (homologue to nerfin-1 in mammals) is a useful marker for prognosis of neuroendocrine tumors. The dynamic expression of Nerfin-1 is regulated post-transcriptionally by multiple microRNAs; however, its post-translational regulation is still unclear. Here we showed that the protein turnover of Nerfin-1 is regulated by Slimb, the substrate adaptor of SCF Slimb ubiquitin ligase complex. Mechanistically, Slimb associates with Nerfin-1 and promotes it ubiquitination and degradation in Drosophila S2R + cells. Furthermore, we determined that the C-terminal half of Nerfin-1 (Nerfin-1 CT ) is required for its binding to Slimb. Genetic epistasis assays showed that Slimb misexpression antagonizes, while knock-down enhances the activity of Nerfin-1 CT in Drosophila eyes. Our data revealed a new link to understand the underlying mechanism for Nerfin-1 turnover in post-translational level, and provided useful insights in animal development and disease treatment by manipulating the activity of Slimb and Nerfin-1. Copyright © 2017 Elsevier Inc. All rights reserved.
IAPs: from caspase inhibitors to modulators of NF-kappaB, inflammation and cancer

DEFF Research Database (Denmark)

Gyrd-Hansen, Mads; Meier, Pascal

2010-01-01

. The development of such inhibitors has radically changed our knowledge of the signalling processes that are regulated by IAPs. Recent studies indicate that IAPs not only regulate caspases and apoptosis, but also modulate inflammatory signalling and immunity, mitogenic kinase signalling, proliferation and mitosis...
A potent and orally active antagonist (SM-406/AT-406) of multiple inhibitor of apoptosis proteins (IAPs) in clinical development for cancer treatment.

Science.gov (United States)

Cai, Qian; Sun, Haiying; Peng, Yuefeng; Lu, Jianfeng; Nikolovska-Coleska, Zaneta; McEachern, Donna; Liu, Liu; Qiu, Su; Yang, Chao-Yie; Miller, Rebecca; Yi, Han; Zhang, Tao; Sun, Duxin; Kang, Sanmao; Guo, Ming; Leopold, Lance; Yang, Dajun; Wang, Shaomeng

2011-04-28

We report the discovery and characterization of SM-406 (compound 2), a potent and orally bioavailable Smac mimetic and an antagonist of the inhibitor of apoptosis proteins (IAPs). This compound binds to XIAP, cIAP1, and cIAP2 proteins with K(i) of 66.4, 1.9, and 5.1 nM, respectively. Compound 2 effectively antagonizes XIAP BIR3 protein in a cell-free functional assay, induces rapid degradation of cellular cIAP1 protein, and inhibits cancer cell growth in various human cancer cell lines. It has good oral bioavailability in mice, rats, non-human primates, and dogs, is highly effective in induction of apoptosis in xenograft tumors, and is capable of complete inhibition of tumor growth. Compound 2 is currently in phase I clinical trials for the treatment of human cancer.
Study of expression of genes cIAP and cMET, in liver tissue with and without neoplasia of Rattus norvegicus

International Nuclear Information System (INIS)

Coto Valverde, Daniel Esteban

2010-01-01

The expression levels of cIAP genes and cMET were determined in liver tissues with and without neoplasm of the organism Rattus norvegicus, for prevention, diagnosis and treatment of hepatocellular carcinoma. The technique of reaction Polymerase Chain in real time (qPCR), is used to obtain the expression, of both genes cIAP and cMET, and this has decreased in neoplastic samples compared to samples not affected. The expression of these genes has been analyzed in samples with neoplastic formations, but treated with an anti-tumor agent. The expression has presented an increase of the cMET gene, unlike the cIAP gene, which has decreased its expression. Perform statistical analysis has been impossible because the number of samples used has been reduced. The results obtained differ with those expected theoretically. (author) [es
DIP1 modulates stem cell homeostasis in Drosophila through regulation of sisR-1.

Science.gov (United States)

Wong, Jing Ting; Akhbar, Farzanah; Ng, Amanda Yunn Ee; Tay, Mandy Li-Ian; Loi, Gladys Jing En; Pek, Jun Wei

2017-10-02

Stable intronic sequence RNAs (sisRNAs) are by-products of splicing and regulate gene expression. How sisRNAs are regulated is unclear. Here we report that a double-stranded RNA binding protein, Disco-interacting protein 1 (DIP1) regulates sisRNAs in Drosophila. DIP1 negatively regulates the abundance of sisR-1 and INE-1 sisRNAs. Fine-tuning of sisR-1 by DIP1 is important to maintain female germline stem cell homeostasis by modulating germline stem cell differentiation and niche adhesion. Drosophila DIP1 localizes to a nuclear body (satellite body) and associates with the fourth chromosome, which contains a very high density of INE-1 transposable element sequences that are processed into sisRNAs. DIP1 presumably acts outside the satellite bodies to regulate sisR-1, which is not on the fourth chromosome. Thus, our study identifies DIP1 as a sisRNA regulatory protein that controls germline stem cell self-renewal in Drosophila.Stable intronic sequence RNAs (sisRNAs) are by-products of splicing from introns with roles in embryonic development in Drosophila. Here, the authors show that the RNA binding protein DIP1 regulates sisRNAs in Drosophila, which is necessary for germline stem cell homeostasis.
Functional Analysis of Drosophila NF1

National Research Council Canada - National Science Library

Bernards, Andre

2005-01-01

...) for Ras, yet homozygous loss of a highly conserved Drosophila NF1 ortholog results in several phenotypes that are insensitive to manipulating Ras signal transduction, but rescued by increasing...
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 seven insect biogenic amines on the expressed receptor and found that it was activated by low concentrations of the Drosophila neuropeptide, pyrokinin-1 (TGPSASSGLWFGPRLamide; EC50, 5 x 10(-8) M). The receptor was also activated by other Drosophila neuropeptides, terminating with the sequence PRLamide...... (Hug-gamma, ecdysis-triggering-hormone-1, pyrokinin-2), but in these cases about six to eight times higher concentrations were needed. The receptor was not activated by Drosophila neuropeptides, containing a C-terminal PRIamide sequence (such as ecdysis-triggering-hormone-2), or PRVamide (such as capa...

IAP-Based Cell Sorting Results in Homogeneous Transplantable Dopaminergic Precursor Cells Derived from Human Pluripotent Stem Cells

Directory of Open Access Journals (Sweden)

Daniela Lehnen

2017-10-01

Full Text Available Human pluripotent stem cell (hPSC-derived mesencephalic dopaminergic (mesDA neurons can relieve motor deficits in animal models of Parkinson's disease (PD. Clinical translation of differentiation protocols requires standardization of production procedures, and surface-marker-based cell sorting is considered instrumental for reproducible generation of defined cell products. Here, we demonstrate that integrin-associated protein (IAP is a cell surface marker suitable for enrichment of hPSC-derived mesDA progenitor cells. Immunomagnetically sorted IAP+ mesDA progenitors showed increased expression of ventral midbrain floor plate markers, lacked expression of pluripotency markers, and differentiated into mature dopaminergic (DA neurons in vitro. Intrastriatal transplantation of IAP+ cells sorted at day 16 of differentiation in a rat model of PD resulted in functional recovery. Grafts from sorted IAP+ mesDA progenitors were more homogeneous in size and DA neuron density. Thus, we suggest IAP-based sorting for reproducible prospective enrichment of mesDA progenitor cells in clinical cell replacement strategies.
Altering the sex determination pathway in Drosophila fat body modifies sex-specific stress responses.

Science.gov (United States)

Argue, Kathryn J; Neckameyer, Wendi S

2014-07-01

The stress response in Drosophila melanogaster reveals sex differences in behavior, similar to what has been observed in mammals. However, unlike mammals, the sex determination pathway in Drosophila is well established, making this an ideal system to identify factors involved in the modulation of sex-specific responses to stress. In this study, we show that the Drosophila fat body, which has been shown to be important for energy homeostasis and sex determination, is a dynamic tissue that is altered in response to stress in a sex and time-dependent manner. We manipulated the sex determination pathway in the fat body via targeted expression of transformer and transformer-2 and analyzed these animals for changes in their response to stress. In the majority of cases, manipulation of transformer or transformer-2 was able to change the physiological output in response to starvation and oxidative stress to that of the opposite sex. Our data also uncover the possibility of additional downstream targets for transformer and transformer-2 that are separate from the sex determination pathway and can influence behavioral and physiological responses. Copyright © 2014 the American Physiological Society.
Determination of the tissue-to-blood partition coefficient for 131iodo-antipyrine in human subcutaneous adipose tissue

DEFF Research Database (Denmark)

Jelnes, R; Astrup, A

1985-01-01

131Iodo-antipyrine (131I-AP) is commonly used for blood flow measurements in adipose tissue. These estimations have been based on the assumption of the tissue-to-blood partition coefficient being 1 ml g-1. No exact determination of the tissue-to-blood partition coefficient for 131I-AP in adipose...... tissue has been carried out. In the present study a partition coefficient of 1.12 +/- 0.06 (mean +/- S.D.) for 131I-AP in adipose tissue has been determined based on the partition coefficient for 131I-AP between lipid-saline (1.24 ml g-1), red blood cells-plasma (0.64 ml g-1), protein-saline (0.19 ml g-1...
IAP-Based Cell Sorting Results in Homogeneous Transplantable Dopaminergic Precursor Cells Derived from Human Pluripotent Stem Cells.

Science.gov (United States)

Lehnen, Daniela; Barral, Serena; Cardoso, Tiago; Grealish, Shane; Heuer, Andreas; Smiyakin, Andrej; Kirkeby, Agnete; Kollet, Jutta; Cremer, Harold; Parmar, Malin; Bosio, Andreas; Knöbel, Sebastian

2017-10-10

Human pluripotent stem cell (hPSC)-derived mesencephalic dopaminergic (mesDA) neurons can relieve motor deficits in animal models of Parkinson's disease (PD). Clinical translation of differentiation protocols requires standardization of production procedures, and surface-marker-based cell sorting is considered instrumental for reproducible generation of defined cell products. Here, we demonstrate that integrin-associated protein (IAP) is a cell surface marker suitable for enrichment of hPSC-derived mesDA progenitor cells. Immunomagnetically sorted IAP + mesDA progenitors showed increased expression of ventral midbrain floor plate markers, lacked expression of pluripotency markers, and differentiated into mature dopaminergic (DA) neurons in vitro. Intrastriatal transplantation of IAP + cells sorted at day 16 of differentiation in a rat model of PD resulted in functional recovery. Grafts from sorted IAP + mesDA progenitors were more homogeneous in size and DA neuron density. Thus, we suggest IAP-based sorting for reproducible prospective enrichment of mesDA progenitor cells in clinical cell replacement strategies. Copyright © 2017 Miltenyi Biotec GmbH. Published by Elsevier Inc. All rights reserved.
Recommendations of 2nd National Consultative Meeting of Indian Academy of Pediatrics (IAP) on polio eradication and improvement of routine immunization.

Science.gov (United States)

Vashishtha, Vipin M; Kalra, Ajay; John, T Jacob; Thacker, Naveen; Agarwal, R K

2008-05-01

Persistence of intense wild poliovirus (WPV) transmission, particularly type 3 in northern India necessitated the Indian Academy of Pediatrics (IAP) to convene a National Consultative Meeting to review its earlier recommendations on polio eradication and improvement of routine immunization. More than thirty experts were invited and intense deliberations were held over two days to draw consensus statements on various issues related with polio eradication. To review the ongoing strategy, identify the existing challenges, and suggest modifications to the current strategy for eradication of poliomyelitis in India. IAP reiterates its support to ongoing efforts on polio eradication but demand some flexibility in the strategy. The immediate challenges identified include persistent WPV type 1 transmission in Uttar Pradesh (UP) and Bihar, intense type 3 transmission also in UP and Bihar, and maintaining polio-free status of all other states. Circulating vaccine derived poliovirus (cVDPV), particularly type 2, was identified as a great future threat. Neglect of routine immunization (RI), poor efficacy of oral polio vaccine (OPV), operational issues, and inadequate uptake of OPV in the 2 endemic states are the main reasons of failure to interrupt transmission of WPV 1 and 3. However, for the first time in history the intensity of WPV 1 circulation is very low in western UP. IAP suggests that high-quality, uniform and consistent performance of supplementary immunization activities (SIAs) in all districts of western UP, particularly using mOPV1(monovalent OPV1) should be maintained to avoid reestablishment of circulation of type 1 poliovirus. A judicious mix of mOPV1 and mOPV3, given sequentially or even simultaneously (after validating the efficacies) will be necessary to address the upsurge of WPV3. Re-establishing routine immunization should be the foremost priority. IAP strongly recommends to Government of India (GOI) to take urgent measures to attain coverage of a minimum
Description and Evaluation of IAP-AACM: A Global-regional Aerosol Chemistry Model for the Earth System Model CAS-ESM

Science.gov (United States)

Wei, Y.; Chen, X.

2017-12-01

We present a first description and evaluation of the IAP Atmospheric Aerosol Chemistry Model (IAP-AACM) which has been integrated into the earth system model CAS-ESM. In this way it is possible to research into interaction of clouds and aerosol by its two-way coupling with the IAP Atmospheric General Circulation Model (IAP-AGCM). The model has a nested global-regional grid based on the Global Environmental Atmospheric Transport Model (GEATM) and the Nested Air Quality Prediction Modeling System (NAQPMS). The AACM provides two optional gas chemistry schemes, the CBM-Z gas chemistry as well as a sulfur oxidize box designed specifically for the CAS-ESM. Now the model driven by AGCM has been applied to a 1-year simulation of tropospheric chemistry both on global and regional scales for 2014, and been evaluated against various observation datasets, including aerosol precursor gas concentration, aerosol mass and number concentrations. Furthermore, global budgets in AACM are compared with other global aerosol models. Generally, the AACM simulations are within the range of other global aerosol model predictions, and the model has a reasonable agreement with observations of gases and particles concentration both on global and regional scales.
Involvement of caspase-2 and caspase-9 in endoplasmic reticulum stress-induced apoptosis: A role for the IAPs

International Nuclear Information System (INIS)

Cheung, Herman H.; Lynn Kelly, N.; Liston, Peter; Korneluk, Robert G.

2006-01-01

Dysregulation of apoptosis is involved in a wide spectrum of disease ranging from proliferative to degenerative disorders. An emerging area of study in apoptosis is the critical contribution of the endoplasmic reticulum (ER) in both mitochondrial and ER specific apoptosis pathways. Here we show that brefeldin A and tunicamycin-mediated ER stress lead to caspase-dependent apoptosis involving caspase-2. Confocal microscopy and subcellular fractionation indicate that caspase-2 is localized to the ER, and following ER stress, the processing of caspase-2 and -9 is an early event preceding the activation of caspase-3 and -7 and the cleavage of the caspase substrate poly(ADP-ribose) polymerase (PARP). Inhibition and silencing of either caspase-2 or caspase-9 suppress ER stress-induced apoptosis, as demonstrated by annexin V binding. Similarly, transduction with an adenovirus encoding either Inhibitors of Apoptosis (IAP) protein HIAP1/c-IAP2 or HIAP2/c-IAP1 also suppresses ER stress-induced apoptosis. However, among HIAP1, HIAP2 and XIAP, only HIAP2 binds and inhibits caspase-2. Our results thus indicate a novel mechanism by which HIAP2 can regulate ER-initiated apoptosis by modulating the activity of caspase-2
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)
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)
Comparison of Brazilian and American norms for the International Affective Picture System (IAPS Comparação entre normas brasileiras e norte-americanas do International Affective Picture System (IAPS

Directory of Open Access Journals (Sweden)

Rafaela Larsen Ribeiro

2005-09-01

Full Text Available OBJECTIVE: The present article compares Brazilian and American norms for the International Affective Picture System (IAPS, a set of normative emotional photographic slides for experimental investigations. METHODS: Subjects were 1,062 Brazilian university students (364 men and 698 women who rated 707 pictures from the IAPS in terms of pleasure, arousal, and dominance following the methodology of the original normative study in the US, enabling direct comparison of data from the two samples through Pearson product moment correlation and Student t test. RESULTS: All correlations were highly significant with the highest level for the pleasure dimension, followed by dominance and arousal. However, contrary to the American normative values, our data showed that Brazilian subjects generally assigned higher arousal ratings overall. CONCLUSION: Our findings confirm that this set of stimuli can be used in Brazil as an affective rating tool due to the high correlations found across the two populations, despite differences on the arousal dimension, which are discussed in detail.OBJETIVO: O presente artigo compara as normas obtidas no Brasil e nos EUA para o "International Affective Picture System" (IAPS, um conjunto de fotografias emocionais amplamente utilizado na investigação experimental. MÉTODOS: Os sujeitos foram 1.062 universitários brasileiros (364 homens e 698 mulheres que avaliaram as 707 fotografias do IAPS nas dimensões prazer, alerta e dominância, utilizando o mesmo procedimento do estudo normativo original realizado nos EUA, permitindo uma comparação direta dos dados através de correlações lineares de Pearson e testes t de Student. RESULTADOS: Todas as correlações entre as populações foram altamente significativas, sendo o maior coeficiente o da dimensão prazer, seguido da dimensão dominância e alerta. Entretanto, os brasileiros atribuíram maiores valores médios à dimensão alerta do que os norte-americanos. CONCLUSÃO: Os
Structural analysis of a functional DIAP1 fragment bound to grim and hid peptides.

Science.gov (United States)

Wu, J W; Cocina, A E; Chai, J; Hay, B A; Shi, Y

2001-07-01

The inhibitor of apoptosis protein DIAP1 suppresses apoptosis in Drosophila, with the second BIR domain (BIR2) playing an important role. Three proteins, Hid, Grim, and Reaper, promote apoptosis, in part by binding to DIAP1 through their conserved N-terminal sequences. The crystal structures of DIAP1-BIR2 by itself and in complex with the N-terminal peptides from Hid and Grim reveal that these peptides bind a surface groove on DIAP1, with the first four amino acids mimicking the binding of the Smac tetrapeptide to XIAP. The next 3 residues also contribute to binding through hydrophobic interactions. Interestingly, peptide binding induces the formation of an additional alpha helix in DIAP1. Our study reveals the structural conservation and diversity necessary for the binding of IAPs by the Drosophila Hid/Grim/Reaper and the mammalian Smac proteins.
A single whole-body low dose X-irradiation does not affect L1, B1 and IAP repeat element DNA methylation longitudinally.

Directory of Open Access Journals (Sweden)

Michelle R Newman

Full Text Available The low dose radioadaptive response has been shown to be protective against high doses of radiation as well as aging-induced genomic instability. We hypothesised that a single whole-body exposure of low dose radiation would induce a radioadaptive response thereby reducing or abrogating aging-related changes in repeat element DNA methylation in mice. Following sham or 10 mGy X-irradiation, serial peripheral blood sampling was performed and differences in Long Interspersed Nucleic Element 1 (L1, B1 and Intracisternal-A-Particle (IAP repeat element methylation between samples were assessed using high resolution melt analysis of PCR amplicons. By 420 days post-irradiation, neither radiation- or aging-related changes in the methylation of peripheral blood, spleen or liver L1, B1 and IAP elements were observed. Analysis of the spleen and liver tissues of cohorts of untreated aging mice showed that the 17-19 month age group exhibited higher repeat element methylation than younger or older mice, with no overall decline in methylation detected with age. This is the first temporal analysis of the effect of low dose radiation on repeat element methylation in mouse peripheral blood and the first to examine the long term effect of this dose on repeat element methylation in a radiosensitive tissue (spleen and a tissue fundamental to the aging process (liver. Our data indicate that the methylation of murine DNA repeat elements can fluctuate with age, but unlike human studies, do not demonstrate an overall aging-related decline. Furthermore, our results indicate that a low dose of ionising radiation does not induce detectable changes to murine repeat element DNA methylation in the tissues and at the time-points examined in this study. This radiation dose is relevant to human diagnostic radiation exposures and suggests that a dose of 10 mGy X-rays, unlike high dose radiation, does not cause significant short or long term changes to repeat element or global DNA
Effect of sterol metabolism in the yeast-Drosophila system on the frequency of radiation-induced aneuploidy in the Drosophila melanogaster oocytes

International Nuclear Information System (INIS)

Savitskii, V.V.; Luchnikova, E.M.; Inge-Vechtomov, S.G.

1986-01-01

The effect of sterol metabolism on induced mutagenesis of Drosophila melanogaster was studied in the ecogenetic system of yeast-Drosophila. Sterol deficiency was created in Drosophila by using the biomass of live cells of Saccharomyces cerevisiae strain 9-2-P712 till mutation in locus nys/sup r1/ blocking the synthesis of ergosterol as the food. It was found that rearing of Drosophila females on the mutant yeast increases the frequency of loss and nondisjunction of X chromosomes induced in mature oocytes by X rays (1000 R). Addition of 0.1% of cholesterol solution in 10% ethanol to the yeast biomass restores the resistance of oocyte to X irradiation to the control level. The possible hormonal effect on membrane leading to increased radiation-induced aneuploidy in Drosophila and the role of sterol metabolism in determining the resistance to various damaging factors are discussed
Racial differences in the expression of inhibitors of apoptosis (IAP) proteins in extracellular vesicles (EV) from prostate cancer patients.

Science.gov (United States)

Khan, Salma; Simpson, Jennifer; Lynch, James C; Turay, David; Mirshahidi, Saied; Gonda, Amber; Sanchez, Tino W; Casiano, Carlos A; Wall, Nathan R

2017-01-01

African-American men with prostate cancer typically develop more aggressive tumors than men from other racial/ethnic groups, resulting in a disproportionately high mortality from this malignancy. This study evaluated differences in the expression of inhibitors of apoptosis proteins (IAPs), a known family of oncoproteins, in blood-derived exosomal vesicles (EV) between African-American and European-American men with prostate cancer. The ExoQuick™ method was used to isolate EV from both plasma and sera of African-American (n = 41) and European-American (n = 31) men with prostate cancer, as well as from controls with no cancer diagnosis (n = 10). EV preparations were quantified by acetylcholinesterase activity assays, and assessed for their IAP content by Western blotting and densitometric analysis. Circulating levels of the IAP Survivin were evaluated by ELISA. We detected a significant increase in the levels of circulating Survivin in prostate cancer patients compared to controls (P<0.01), with the highest levels in African-American patients (P<0.01). African-American patients with prostate cancer also contained significantly higher amounts of EVs in their plasma (P<0.01) and sera (P<0.05) than European-American patients. In addition, EVs from African-American patients with prostate cancer contained significantly higher amounts of the IAPs Survivin (P<0.05), XIAP (P<0.001), and cIAP-2 (P<0.01) than EVs from European-American patients. There was no significant correlation between expression of IAPs and clinicopathological parameters in the two patient groups. Increased expression of IAPs in EVs from African-American patients with prostate cancer may influence tumor aggressiveness and contribute to the mortality disparity observed in this patient population. EVs could serve as reservoirs of novel biomarkers and therapeutic targets that may have clinical utility in reducing prostate cancer health disparities.
Racial differences in the expression of inhibitors of apoptosis (IAP proteins in extracellular vesicles (EV from prostate cancer patients.

Directory of Open Access Journals (Sweden)

Salma Khan

Full Text Available African-American men with prostate cancer typically develop more aggressive tumors than men from other racial/ethnic groups, resulting in a disproportionately high mortality from this malignancy. This study evaluated differences in the expression of inhibitors of apoptosis proteins (IAPs, a known family of oncoproteins, in blood-derived exosomal vesicles (EV between African-American and European-American men with prostate cancer. The ExoQuick™ method was used to isolate EV from both plasma and sera of African-American (n = 41 and European-American (n = 31 men with prostate cancer, as well as from controls with no cancer diagnosis (n = 10. EV preparations were quantified by acetylcholinesterase activity assays, and assessed for their IAP content by Western blotting and densitometric analysis. Circulating levels of the IAP Survivin were evaluated by ELISA. We detected a significant increase in the levels of circulating Survivin in prostate cancer patients compared to controls (P<0.01, with the highest levels in African-American patients (P<0.01. African-American patients with prostate cancer also contained significantly higher amounts of EVs in their plasma (P<0.01 and sera (P<0.05 than European-American patients. In addition, EVs from African-American patients with prostate cancer contained significantly higher amounts of the IAPs Survivin (P<0.05, XIAP (P<0.001, and cIAP-2 (P<0.01 than EVs from European-American patients. There was no significant correlation between expression of IAPs and clinicopathological parameters in the two patient groups. Increased expression of IAPs in EVs from African-American patients with prostate cancer may influence tumor aggressiveness and contribute to the mortality disparity observed in this patient population. EVs could serve as reservoirs of novel biomarkers and therapeutic targets that may have clinical utility in reducing prostate cancer health disparities.
Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells

Energy Technology Data Exchange (ETDEWEB)

Shekhar, Tanmay M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Green, Maja M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Department of Anatomy & Neuroscience, The University of Melbourne, Parkville 3010 (Australia); Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Hawkins, Christine J., E-mail: c.hawkins@latrobe.edu.au [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia)

2015-07-15

Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict
Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells

International Nuclear Information System (INIS)

Shekhar, Tanmay M.; Green, Maja M.; Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M.; Hawkins, Christine J.

2015-01-01

Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict
Finite-volume Atmospheric Model of the IAP/LASG (FAMIL)

Science.gov (United States)

Bao, Q.

2015-12-01

The Finite-volume Atmospheric Model of the IAP/LASG (FAMIL) is introduced in this work. FAMIL have the flexible horizontal and vertical resolutions up to 25km and 1Pa respectively, which currently running on the "Tianhe 1A&2" supercomputers. FAMIL is the atmospheric component of the third-generation Flexible Global Ocean-Atmosphere-Land climate System model (FGOALS3) which will participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6). In addition to describing the dynamical core and physical parameterizations of FAMIL, this talk describes the simulated characteristics of energy and water balances, precipitation, Asian Summer Monsoon and stratospheric circulation, and compares them with observational/reanalysis data. Finally, the model biases as well as possible solutions are discussed.
NF-1 Dependent Gene Regulation in Drosophila Melanogaster

National Research Council Canada - National Science Library

Zhong, Yi

2004-01-01

.... We have used an Affymetrix whole genome chip, containing all 13,500 genes of the fruit fly Drosophila, to identify 93 genes with altered expression patterns in flies that have no NF1 protein compared...
A small molecule for a big transformation: Topical application of a 20-nucleotide-long antisense fragment of the DIAP-2 gene inhibits the development of Drosophila melanogaster female imagos

Directory of Open Access Journals (Sweden)

Nyadar Palmah M.

2018-01-01

Full Text Available Several genes have been identified to play important roles associated with sex selection in Drosophila melanogaster. An essential part is attributed to the sex-lethal gene that depends on the expression of the X:A (number of chromosomes to autosomes ratio signal controlling both sex selection and dosage compensation processes in D. melanogaster. Interestingly, for sex selection in D. melanogaster there are no documented data addressing the role of the inhibitor of apoptosis (IAP genes and their signaling influence on this biological process. In this study, we found that topical application of a 20-nucleotide-long antisense DNA fragment (oligoDIAP-2 from the death-associated inhibitor of apoptosis (DIAP-2 gene interferes with D. melanogaster development and significantly decreases the number of female imagos and their biomass. We show that the applied antisense oligoDIAP-2 fragment downregulates the target DIAP-2 gene whose normal concentration is necessary for the development of female D. melanogaster. These data correspond to the results on downregulation of the target host IAP-Z gene of Lymantria dispar L. female imagos after topical treatment with an 18-nucleotide-long antisense DNA fragment from the L. dispar multicapsid nuclear polyhedrosis virus IAP-3 gene at the larval stage. The observed novel phenomenon linking the downregulation of insect IAP genes and the low rate of female imago development could have practical application, especially in insect pest control and molecular pathology.

Drosophila arginine methyltransferase 1 (DART1) is an ecdysone receptor co-repressor

International Nuclear Information System (INIS)

Kimura, Shuhei; Sawatsubashi, Shun; Ito, Saya; Kouzmenko, Alexander; Suzuki, Eriko; Zhao, Yue; Yamagata, Kaoru; Tanabe, Masahiko; Ueda, Takashi; Fujiyama, Sari; Murata, Takuya; Matsukawa, Hiroyuki; Takeyama, Ken-ichi; Yaegashi, Nobuo

2008-01-01

Histone arginine methylation is an epigenetic marker that regulates gene expression by defining the chromatin state. Arginine methyltransferases, therefore, serve as transcriptional co-regulators. However, unlike other transcriptional co-regulators, the physiological roles of arginine methyltransferases are poorly understood. Drosophila arginine methyltransferase 1 (DART1), the mammalian PRMT1 homologue, methylates the arginine residue of histone H4 (H4R3me2). Disruption of DART1 in Drosophila by imprecise P-element excision resulted in low viability during metamorphosis in the pupal stages. In the pupal stage, an ecdysone hormone signal is critical for developmental progression. DART1 interacted with the nuclear ecdysone receptor (EcR) in a ligand-dependent manner, and co-repressed EcR in intact flies. These findings suggest that DART1, a histone arginine methyltransferase, is a co-repressor of EcR that is indispensable for normal pupal development in the intact fly
The route of infection determines Wolbachia antibacterial protection in Drosophila.

Science.gov (United States)

Gupta, Vanika; Vasanthakrishnan, Radhakrishnan B; Siva-Jothy, Jonathon; Monteith, Katy M; Brown, Sam P; Vale, Pedro F

2017-06-14

Bacterial symbionts are widespread among metazoans and provide a range of beneficial functions. Wolbachia -mediated protection against viral infection has been extensively demonstrated in Drosophila. In mosquitoes that are artificially transinfected with Drosophila melanogaster Wolbachia (wMel), protection from both viral and bacterial infections has been demonstrated. However, no evidence for Wolbachia -mediated antibacterial protection has been demonstrated in Drosophila to date. Here, we show that the route of infection is key for Wolbachia -mediated antibacterial protection. Drosophila melanogaster carrying Wolbachia showed reduced mortality during enteric-but not systemic-infection with the opportunist pathogen Pseudomonas aeruginosa Wolbachia -mediated protection was more pronounced in male flies and is associated with increased early expression of the antimicrobial peptide Attacin A , and also increased expression of a reactive oxygen species detoxification gene ( Gst D8 ). These results highlight that the route of infection is important for symbiont-mediated protection from infection, that Wolbachia can protect hosts by eliciting a combination of resistance and disease tolerance mechanisms, and that these effects are sexually dimorphic. We discuss the importance of using ecologically relevant routes of infection to gain a better understanding of symbiont-mediated protection. © 2017 The Authors.
E3 Ligase cIAP2 Mediates Downregulation of MRE11 and Radiosensitization in Response to HDAC Inhibition in Bladder Cancer.

Science.gov (United States)

Nicholson, Judith; Jevons, Sarah J; Groselj, Blaz; Ellermann, Sophie; Konietzny, Rebecca; Kerr, Martin; Kessler, Benedikt M; Kiltie, Anne E

2017-06-01

The MRE11/RAD50/NBS1 (MRN) complex mediates DNA repair pathways, including double-strand breaks induced by radiotherapy. Meiotic recombination 11 homolog (MRE11) is downregulated by histone deacetylase inhibition (HDACi), resulting in reduced levels of DNA repair in bladder cancer cells and radiosensitization. In this study, we show that the mechanism of this downregulation is posttranslational and identify a C-terminally truncated MRE11, which is formed after HDAC inhibition as full-length MRE11 is downregulated. Truncated MRE11 was stabilized by proteasome inhibition, exhibited a decreased half-life after treatment with panobinostat, and therefore represents a newly identified intermediate induced and degraded in response to HDAC inhibition. The E3 ligase cellular inhibitor of apoptosis protein 2 (cIAP2) was upregulated in response to HDAC inhibition and was validated as a new MRE11 binding partner whose upregulation had similar effects to HDAC inhibition. cIAP2 overexpression resulted in downregulation and altered ubiquitination patterns of MRE11 and mediated radiosensitization in response to HDAC inhibition. These results highlight cIAP2 as a player in the DNA damage response as a posttranscriptional regulator of MRE11 and identify cIAP2 as a potential target for biomarker discovery or chemoradiation strategies in bladder cancer. Cancer Res; 77(11); 3027-39. ©2017 AACR . ©2017 American Association for Cancer Research.
Biological effects of radon in Drosophila

International Nuclear Information System (INIS)

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

1992-04-01

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)
Wavelength Discrimination in Drosophila Suggests a Role of Rhodopsin 1 in Color Vision

OpenAIRE

Garbers, Christian; Wachtler, Thomas

2016-01-01

Among the five photoreceptor opsins in the eye of Drosophila, Rhodopsin 1 (Rh1) is expressed in the six outer photoreceptors. In a previous study that combined behavioral genetics with computational modeling, we demonstrated that flies can use the signals from Rh1 for color vision. Here, we provide an in-depth computational analysis of wildtype Drosophila wavelength discrimination specifically considering the consequences of different choices of computations in the preprocessing of the behavi...
The Rho-family GTPase Rac1 regulates integrin localization in Drosophila immunosurveillance cells.

Directory of Open Access Journals (Sweden)

Miguel J Xavier

Full Text Available BACKGROUND: When the parasitoid wasp Leptopilina boulardi lays an egg in a Drosophila larva, phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. The Drosophila β-integrin Myospheroid (Mys is necessary for lamellocytes to adhere to the cellular capsule surrounding L. boulardi eggs. Integrins are heterodimeric adhesion receptors consisting of α and β subunits, and similar to other plasma membrane receptors undergo ligand-dependent endocytosis. In mammalian cells it is known that integrin binding to the extracellular matrix induces the activation of Rac GTPases, and we have previously shown that Rac1 and Rac2 are necessary for a proper encapsulation response in Drosophila larvae. We wanted to test the possibility that Myospheroid and Rac GTPases interact during the Drosophila anti-parasitoid immune response. RESULTS: In the current study we demonstrate that Rac1 is required for the proper localization of Myospheroid to the cell periphery of haemocytes after parasitization. Interestingly, the mislocalization of Myospheroid in Rac1 mutants is rescued by hyperthermia, involving the heat shock protein Hsp83. From these results we conclude that Rac1 and Hsp83 are required for the proper localization of Mys after parasitization. SIGNIFICANCE: We show for the first time that the small GTPase Rac1 is required for Mysopheroid localization. Interestingly, the necessity of Rac1 in Mys localization was negated by hyperthermia. This presents a problem, in Drosophila we quite often raise larvae at 29°C when using the GAL4/UAS misexpression system. If hyperthermia rescues receptor endosomal recycling defects, raising larvae in hyperthermic conditions may mask potentially interesting phenotypes.
Selecting pure-emotion materials from the International Affective Picture System (IAPS by Chinese university students: A study based on intensity-ratings only

Directory of Open Access Journals (Sweden)

Zhicha Xu

2017-08-01

Full Text Available There is a need to use selected pictures with pure emotion as stimulation or treatment media for basic and clinical research. Pictures from the widely-used International Affective Picture System (IAPS contain rich emotions, but no study has clearly stated that an emotion is exclusively expressed in its putative IAPS picture to date. We hypothesize that the IAPS images contain at least pure vectors of disgust, erotism (or erotica, fear, happiness, sadness and neutral emotions. Accordingly, we have selected 108 IAPS images, each with a specific emotion, and invited 219 male and 274 female university students to rate only the intensity of the emotion conveyed in each picture. Their answers were analyzed using exploratory and confirmatory factor analysis. Four first-order factors manifested as disgust-fear, happiness-sadness, erotism, and neutral. Later, ten second-order sub-factors manifested as mutilation-disgust, vomit-disgust, food-disgust, violence-fear, happiness, sadness, couple- erotism, female-erotism, male- erotism, and neutral. Fifty-nine pictures for the ten sub-factors, which had established good model-fit indices, satisfactory sub-factor internal reliabilities, and prominent gender-differences in the picture intensity ratings were ultimately retained. We thus have selected a series of pure-emotion IAPS pictures, which together displayed both satisfactorily convergent and discriminant structure-validities. We did not intend to evaluate all IAPS items, but instead selected some pictures conveying pure emotions, which might help both basic and clinical researches in the future.
Cross-cultural validation of the "International affective picture system" (IAPS on a sample from Bosnia and Herzegovina

Directory of Open Access Journals (Sweden)

Drače Saša

2013-01-01

Full Text Available In this study the normative ratings of the International Affective Picture System (IAPS, Center for the Study of Emotion and Attention [CSEA], 1995 were compared with the ratings from a Bosnian sample. Seventy-two psychology undergraduates from the University of Sarajevo (Bosnia and Herzegovina rated valence, dominance and arousal for a stratified sample of 60 pictures that was selected from the IAPS. Reliability coefficients indicate that the self-report ratings are internally consistent. The affective ratings from our sample correlated strongly with the North American ratings at: .95, .81 and .91, respectively for valence, arousal and dominance. Consistent with expectations, mean valence and dominance ratings did not differ significantly between the Bosnian and North American sample. Furthermore, plotting of the Bosnian valence and arousal ratings results in a similar boomerang shaped distribution as the North American affective ratings. Taken together, findings obtained from the Bosnian sample confirm the cross-cultural validity of the IAPS.
The Sex Determination Gene transformer Regulates Male-Female Differences in Drosophila Body Size.

Science.gov (United States)

Rideout, Elizabeth J; Narsaiya, Marcus S; Grewal, Savraj S

2015-12-01

Almost all animals show sex differences in body size. For example, in Drosophila, females are larger than males. Although Drosophila is widely used as a model to study growth, the mechanisms underlying this male-female difference in size remain unclear. Here, we describe a novel role for the sex determination gene transformer (tra) in promoting female body growth. Normally, Tra is expressed only in females. We find that loss of Tra in female larvae decreases body size, while ectopic Tra expression in males increases body size. Although we find that Tra exerts autonomous effects on cell size, we also discovered that Tra expression in the fat body augments female body size in a non cell-autonomous manner. These effects of Tra do not require its only known targets doublesex and fruitless. Instead, Tra expression in the female fat body promotes growth by stimulating the secretion of insulin-like peptides from insulin producing cells in the brain. Our data suggest a model of sex-specific growth in which body size is regulated by a previously unrecognized branch of the sex determination pathway, and identify Tra as a novel link between sex and the conserved insulin signaling pathway.
The Sex Determination Gene transformer Regulates Male-Female Differences in Drosophila Body Size.

Directory of Open Access Journals (Sweden)

Elizabeth J Rideout

2015-12-01

Full Text Available Almost all animals show sex differences in body size. For example, in Drosophila, females are larger than males. Although Drosophila is widely used as a model to study growth, the mechanisms underlying this male-female difference in size remain unclear. Here, we describe a novel role for the sex determination gene transformer (tra in promoting female body growth. Normally, Tra is expressed only in females. We find that loss of Tra in female larvae decreases body size, while ectopic Tra expression in males increases body size. Although we find that Tra exerts autonomous effects on cell size, we also discovered that Tra expression in the fat body augments female body size in a non cell-autonomous manner. These effects of Tra do not require its only known targets doublesex and fruitless. Instead, Tra expression in the female fat body promotes growth by stimulating the secretion of insulin-like peptides from insulin producing cells in the brain. Our data suggest a model of sex-specific growth in which body size is regulated by a previously unrecognized branch of the sex determination pathway, and identify Tra as a novel link between sex and the conserved insulin signaling pathway.
Research of the low dose gamma-irradiation influence on life span and aging speed of Drosophila melanogaster

International Nuclear Information System (INIS)

Moskalev, A.

2003-01-01

Full text: Researches of radioinduced life span alteration of Drosophila which is carried out in our laboratory in 1996-2003 years, have revealed interrelation between mutations of several genes of DNA repair and apoptosis pathways with low doses ionizing irradiation and speed of aging. It was used Drosophila individuals, developing in conditions of a chronic low dose irradiation or on nutrition medium with apoptosis inducer etoposide addition. The exposition doze was 0.17 sGy/h. The absorbed doze for one generation (from an embryo stage up to an imago start, 10-12 days) corresponded 60 sGy. Etoposide treatment carried out on preimago stages (5 mkM in a nutrient medium n concentration). We investigated the life span after irradiation and etoposide treatment of Drosophila melanogaster laboratory populations with defects of some genes of DNA repair machinery and apoptosis pathways in homozygous and heterozygous state, such as mei-41 (ATM homolog), two alleles of Dcp-1 (Drosophila caspase), dArk (Apaf-1 homolog), rpr, grim, hid, three alleles of th (IAP homolog), wg (Wnt family member). It is shown, that the irradiation and etoposide treatment of these strains results in life span change depending on a genotype of the investigated line. The results will be considering in the report. As well, the analysis of age-dependent change of nervous system activity (as the test of aging speed) of Drosophila melanogaster imago was carried out. It was shown, that the irradiation of strains with the increased apoptosis sensitivity results in elevated nervous - muscular activity of imago during all experiment periods. At th1 strain increase of activity in comparison with the control in the first week has made 41 %, and in two subsequent - about 80 %. Last week authentic increase did not observe. At th4 strain statistically significant increase of activity in comparison with the control observed in the first week of experiment (18 %), in the second (67 %) and the fourth (88 %). The
Recognition and Detoxification of the Insecticide DDT by Drosophila melanogaster Glutathione S-Transferase D1

Energy Technology Data Exchange (ETDEWEB)

Low, Wai Yee; Feil, Susanne C.; Ng, Hooi Ling; Gorman, Michael A.; Morton, Craig J.; Pyke, James; McConville, Malcolm J.; Bieri, Michael; Mok, Yee-Foong; Robin, Charles; Gooley, Paul R.; Parker, Michael W.; Batterham, Philip (SVIMR-A); (Melbourne)

2010-06-14

GSTD1 is one of several insect glutathione S-transferases capable of metabolizing the insecticide DDT. Here we use crystallography and NMR to elucidate the binding of DDT and glutathione to GSTD1. The crystal structure of Drosophila melanogaster GSTD1 has been determined to 1.1 {angstrom} resolution, which reveals that the enzyme adopts the canonical GST fold but with a partially occluded active site caused by the packing of a C-terminal helix against one wall of the binding site for substrates. This helix would need to unwind or be displaced to enable catalysis. When the C-terminal helix is removed from the model of the crystal structure, DDT can be computationally docked into the active site in an orientation favoring catalysis. Two-dimensional {sup 1}H,{sup 15}N heteronuclear single-quantum coherence NMR experiments of GSTD1 indicate that conformational changes occur upon glutathione and DDT binding and the residues that broaden upon DDT binding support the predicted binding site. We also show that the ancestral GSTD1 is likely to have possessed DDT dehydrochlorinase activity because both GSTD1 from D. melanogaster and its sibling species, Drosophila simulans, have this activity.
Radioresistance and radiosensitivity in Drosophila melanogaster

International Nuclear Information System (INIS)

Reguly, M.L.

1983-01-01

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.) [pt
Drosophila PAF1 Modulates PIWI/piRNA Silencing Capacity.

Science.gov (United States)

Clark, Josef P; Rahman, Reazur; Yang, Nachen; Yang, Linda H; Lau, Nelson C

2017-09-11

To test the directness of factors in initiating PIWI-directed gene silencing, we employed a Piwi-interacting RNA (piRNA)-targeted reporter assay in Drosophila ovary somatic sheet (OSS) cells [1]. This assay confirmed direct silencing roles for piRNA biogenesis factors and PIWI-associated factors [2-12] but suggested that chromatin-modifying proteins may act downstream of the initial silencing event. Our data also revealed that RNA-polymerase-II-associated proteins like PAF1 and RTF1 antagonize PIWI-directed silencing. PAF1 knockdown enhances PIWI silencing of reporters when piRNAs target the transcript region proximal to the promoter. Loss of PAF1 suppresses endogenous transposable element (TE) transcript maturation, whereas a subset of gene transcripts and long-non-coding RNAs adjacent to TE insertions are affected by PAF1 knockdown in a similar fashion to piRNA-targeted reporters. Additionally, transcription activation at specific TEs and TE-adjacent loci during PIWI knockdown is suppressed when PIWI and PAF1 levels are both reduced. Our study suggests a mechanistic conservation between fission yeast PAF1 repressing AGO1/small interfering RNA (siRNA)-directed silencing [13, 14] and Drosophila PAF1 opposing PIWI/piRNA-directed silencing. Copyright © 2017 Elsevier Ltd. All rights reserved.
Drosophila pink1 is required for mitochondrial function and interacts genetically with parkin.

Science.gov (United States)

Clark, Ira E; Dodson, Mark W; Jiang, Changan; Cao, Joseph H; Huh, Jun R; Seol, Jae Hong; Yoo, Soon Ji; Hay, Bruce A; Guo, Ming

2006-06-29

Parkinson's disease is the second most common neurodegenerative disorder and is characterized by the degeneration of dopaminergic neurons in the substantia nigra. Mitochondrial dysfunction has been implicated as an important trigger for Parkinson's disease-like pathogenesis because exposure to environmental mitochondrial toxins leads to Parkinson's disease-like pathology. Recently, multiple genes mediating familial forms of Parkinson's disease have been identified, including PTEN-induced kinase 1 (PINK1; PARK6) and parkin (PARK2), which are also associated with sporadic forms of Parkinson's disease. PINK1 encodes a putative serine/threonine kinase with a mitochondrial targeting sequence. So far, no in vivo studies have been reported for pink1 in any model system. Here we show that removal of Drosophila PINK1 homologue (CG4523; hereafter called pink1) function results in male sterility, apoptotic muscle degeneration, defects in mitochondrial morphology and increased sensitivity to multiple stresses including oxidative stress. Pink1 localizes to mitochondria, and mitochondrial cristae are fragmented in pink1 mutants. Expression of human PINK1 in the Drosophila testes restores male fertility and normal mitochondrial morphology in a portion of pink1 mutants, demonstrating functional conservation between human and Drosophila Pink1. Loss of Drosophila parkin shows phenotypes similar to loss of pink1 function. Notably, overexpression of parkin rescues the male sterility and mitochondrial morphology defects of pink1 mutants, whereas double mutants removing both pink1 and parkin function show muscle phenotypes identical to those observed in either mutant alone. These observations suggest that pink1 and parkin function, at least in part, in the same pathway, with pink1 functioning upstream of parkin. The role of the pink1-parkin pathway in regulating mitochondrial function underscores the importance of mitochondrial dysfunction as a central mechanism of Parkinson's disease
Structure and novel functional mechanism of Drosophila SNF in sex-lethal splicing.

Directory of Open Access Journals (Sweden)

Jicheng Hu

Full Text Available Sans-fille (SNF is the Drosophila homologue of mammalian general splicing factors U1A and U2B'', and it is essential in Drosophila sex determination. We found that, besides its ability to bind U1 snRNA, SNF can also bind polyuridine RNA tracts flanking the male-specific exon of the master switch gene Sex-lethal (Sxl pre-mRNA specifically, similar to Sex-lethal protein (SXL. The polyuridine RNA binding enables SNF directly inhibit Sxl exon 3 splicing, as the dominant negative mutant SNF(1621 binds U1 snRNA but not polyuridine RNA. Unlike U1A, both RNA recognition motifs (RRMs of SNF can recognize polyuridine RNA tracts independently, even though SNF and U1A share very high sequence identity and overall structure similarity. As SNF RRM1 tends to self-associate on the opposite side of the RNA binding surface, it is possible for SNF to bridge the formation of super-complexes between two introns flanking Sxl exon 3 or between a intron and U1 snRNP, which serves the molecular basis for SNF to directly regulate Sxl splicing. Taken together, a new functional model for SNF in Drosophila sex determination is proposed. The key of the new model is that SXL and SNF function similarly in promoting Sxl male-specific exon skipping with SNF being an auxiliary or backup to SXL, and it is the combined dose of SXL and SNF governs Drosophila sex determination.
Melanoma inhibitor of apoptosis protein (ML-IAP) specific cytotoxic T lymphocytes cross-react with an epitope from the auto-antigen SS56

DEFF Research Database (Denmark)

Baek Sørensen, Rikke; Faurschou, Mikkel; Troelsen, Lone

2009-01-01

A large proportion of melanoma patients host a spontaneous T-cell response specifically against ML-IAP-derived peptides. In this study, we describe that some ML-IAP-specific cytotoxic T cells isolated from melanoma patients cross react with an epitope from the auto-antigen SS56. SS56 is a recentl...
The Drosophila homolog of the mammalian imprint regulator, CTCF, maintains the maternal genomic imprint in Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Rasheva Vanya

2010-07-01

Full Text Available Abstract Background CTCF is a versatile zinc finger DNA-binding protein that functions as a highly conserved epigenetic transcriptional regulator. CTCF is known to act as a chromosomal insulator, bind promoter regions, and facilitate long-range chromatin interactions. In mammals, CTCF is active in the regulatory regions of some genes that exhibit genomic imprinting, acting as insulator on only one parental allele to facilitate parent-specific expression. In Drosophila, CTCF acts as a chromatin insulator and is thought to be actively involved in the global organization of the genome. Results To determine whether CTCF regulates imprinting in Drosophila, we generated CTCF mutant alleles and assayed gene expression from the imprinted Dp(1;fLJ9 mini-X chromosome in the presence of reduced CTCF expression. We observed disruption of the maternal imprint when CTCF levels were reduced, but no effect was observed on the paternal imprint. The effect was restricted to maintenance of the imprint and was specific for the Dp(1;fLJ9 mini-X chromosome. Conclusions CTCF in Drosophila functions in maintaining parent-specific expression from an imprinted domain as it does in mammals. We propose that Drosophila CTCF maintains an insulator boundary on the maternal X chromosome, shielding genes from the imprint-induced silencing that occurs on the paternally inherited X chromosome. See commentary: http://www.biomedcentral.com/1741-7007/8/104
Genetic and pharmacological screens converge in identifying FLIP, BCL2 and IAP proteins as key regulators of sensitivity to the TRAIL-inducing anti-cancer agent ONC201/TIC10

Science.gov (United States)

Allen, Joshua E.; Prabhu, Varun V.; Talekar, Mala; van den Heuvel, AP; Lim, Bora; Dicker, David T.; Fritz, Jennifer L.; Beck, Adam; El-Deiry, Wafik S.

2015-01-01

ONC201/TIC10 is a small molecule inducer of the TRAIL gene under current investigation as a novel anticancer agent. In this study, we identify critical molecular determinants of ONC201 sensitivity offering potential utility as pharmacodynamic or predictive response markers. By screening a library of kinase siRNAs in combination with a subcytotoxic dose of ONC201, we identified several kinases that ablated tumor cell sensitivity, including the MAPK pathway inducer KSR1. Unexpectedly, KSR1 silencing did not affect MAPK signaling in the presence or absence of ONC201, but instead reduced expression of the anti-apoptotic proteins FLIP, Mcl-1, Bcl-2, cIAP1, cIAP2, and survivin. In parallel to this work, we also conducted a synergy screen in which ONC201 was combined with approved small molecule anticancer drugs. In multiple cancer cell populations, ONC201 synergized with diverse drug classes including the multi-kinase inhibitor sorafenib. Notably, combining ONC201 and sorafenib led to synergistic induction of TRAIL and its receptor DR5 along with a potent induction of cell death. In a mouse xenograft model of hepatocellular carcinoma, we demonstrated that ONC201 and sorafenib cooperatively and safely triggered tumor regressions. Overall, our results established a set of determinants for ONC201 sensitivity that may predict therapeutic response, particularly in settings of sorafenib co-treatment to enhance anticancer responses. PMID:25681273
Investigating the effects of nanoparticles on reproduction and development in Drosophila melanogaster and CD-1 mice

Science.gov (United States)

Philbrook, Nicola Anne

Manufactured nanoparticles (NPs) are a class of small (≤ 100 nm) materials that are being used for a variety of purposes, including industrial lubricants, food additives, antibacterial agents, as well as delivery systems for drug and gene therapies. Their unique characteristics due to their small size as well as their parent materials allow them to be exploited in convenience applications; however, some of these properties also allow them to interact with and invade biological systems. Few studies have been performed to determine the potential harm that NPs can inflict on reproductive and developmental processes in organisms. In this study, Drosophila melanogaster and CD-1 mice were orally exposed to varying doses of titanium dioxide (TiO 2) NPs, silver (Ag) NPs, or hydroxyl-functionalized carbon nanotubes (fCNTs) and Drosophila were also exposed to microparticles (MPs) as a control for particle size. The subsequent effect of these materials on reproduction and development were evaluated. Strikingly, each type of NP studied negatively affected either reproduction or development in one or both of the two model systems. TiO2 NPs significantly negative effected both CD-1 mouse development (100 mg/kg or 1000 mg/kg) as well as Drosophila female fecundity (0.005%-0.5% w/v). Ag NPs significantly reduced mouse fetus viability after prenatal exposure to10 mg/kg. Ag NPs also significantly decreased the developmental success of Drosophila when they were directly exposed to these NPs (0.05% - 0.5% w/v) compared to both the vehicle and MP controls. fCNTs significantly increased the presence of morphological defects, resorptions and skeletal abnormalities in CD-1 mice, but had little effect on Drosophila. We speculate that the differences seen in the effects of NP types may be partially due to differences in reproductive physiology as well as each organism's ability to internalize these NPs. Whereas the differing response of each organism to a NP type was likely due in part to

Drosophila mitotypes determine developmental time in a diet and temperature dependent manner.

Science.gov (United States)

Towarnicki, Samuel G; Ballard, J William O

2017-07-01

It is well known that specific mitochondrial (mt) DNA mutations can reduce organismal fitness and influence mitochondrial-nuclear interactions. However, determining specific mtDNA mutations that are beneficial has been elusive. In this study, we vary the diet and environmental temperature to study larval development time of two Drosophila melanogaster mitotypes (Alstonville and Dahomey), in two nuclear genetic backgrounds, and investigate developmental differences through weight, feeding rate, and movement. To manipulate the diet, we utilize the nutritional geometric framework to manipulate isocaloric diets of differing macronutrient ratios (1:2 and 1:16 protein: carbohydrate (P:C) ratios) and raise flies at three temperatures (19°C, 23°C and 27°C). Larvae with Dahomey mtDNA develop more slowly than Alstonville when fed the 1:2 P:C diet at all temperatures and developed more quickly when fed the 1:16 P:C diet at 23°C and 27°C. We determined that Dahomey larvae eat more, move less, and weigh more than Alstonville larvae when raised on the 1:16 P:C diet and that these physiological responses are modified by temperature. We suggest that 1 (or more) of 4 mtDNA changes is likely responsible for the observed effects and posit the mtDNA changes moderate a physiological trade-off between consumption and foraging. Copyright © 2017 Elsevier Ltd. All rights reserved.
Identification of four Drosophila allatostatins as the cognate ligands for the Drosophila orphan receptor DAR-2

DEFF Research Database (Denmark)

Lenz, C; Williamson, M; Hansen, G N

2001-01-01

The allatostatins are generally inhibitory insect neuropeptides. The Drosophila orphan receptor DAR-2 is a G-protein-coupled receptor, having 47% amino acid residue identity with another Drosophila receptor, DAR-1 (which is also called dros. GPCR, or DGR) that was previously shown...... to be the receptor for an intrinsic Drosophila A-type (cockroach-type) allatostatin. Here, we have permanently expressed DAR-2 in CHO cells and found that it is the cognate receptor for four Drosophila A-type allatostatins, the drostatins-A1 to -A4. Of all the drostatins, drostatin-A4 (Thr...... weakly in the brain. The Drosophila larval gut also contains about 20-30 endocrine cells, expressing the gene for the drostatins-A1 to -A4. We suggest, therefore, that DAR-2 mediates an allatostatin (drostatin)-induced inhibition of gut motility. This is the first report on the permanent and functional...
Synaptic and genomic responses to JNK and AP-1 signaling in Drosophila neurons

Directory of Open Access Journals (Sweden)

Bohmann Dirk

2005-06-01

Full Text Available Abstract Background The transcription factor AP-1 positively controls synaptic plasticity at the Drosophila neuromuscular junction. Although in motor neurons, JNK has been shown to activate AP-1, a positive regulator of growth and strength at the larval NMJ, the consequences of JNK activation are poorly studied. In addition, the downstream transcriptional targets of JNK and AP-1 signaling in the Drosophila nervous system have yet to be identified. Here, we further investigated the role of JNK signaling at this model synapse employing an activated form of JNK-kinase; and using Serial Analysis of Gene Expression and oligonucleotide microarrays, searched for candidate early targets of JNK or AP-1 dependent transcription in neurons. Results Temporally-controlled JNK induction in postembryonic motor neurons triggers synaptic growth at the NMJ indicating a role in developmental plasticity rather than synaptogenesis. An unexpected observation that JNK activation also causes a reduction in transmitter release is inconsistent with JNK functioning solely through AP-1 and suggests an additional, yet-unidentified pathway for JNK signaling in motor neurons. SAGE profiling of mRNA expression helps define the neural transcriptome in Drosophila. Though many putative AP-1 and JNK target genes arose from the genomic screens, few were confirmed in subsequent validation experiments. One potentially important neuronal AP-1 target discovered, CG6044, was previously implicated in olfactory associative memory. In addition, 5 mRNAs regulated by RU486, a steroid used to trigger conditional gene expression were identified. Conclusion This study demonstrates a novel role for JNK signaling at the larval neuromuscular junction and provides a quantitative profile of gene transcription in Drosophila neurons. While identifying potential JNK/AP-1 targets it reveals the limitations of genome-wide analyses using complex tissues like the whole brain.
Genetic and Pharmacological Screens Converge in Identifying FLIP, BCL2, and IAP Proteins as Key Regulators of Sensitivity to the TRAIL-Inducing Anticancer Agent ONC201/TIC10.

Science.gov (United States)

Allen, Joshua E; Prabhu, Varun V; Talekar, Mala; van den Heuvel, A Pieter J; Lim, Bora; Dicker, David T; Fritz, Jennifer L; Beck, Adam; El-Deiry, Wafik S

2015-04-15

ONC201/TIC10 is a small-molecule inducer of the TRAIL gene under current investigation as a novel anticancer agent. In this study, we identify critical molecular determinants of ONC201 sensitivity offering potential utility as pharmacodynamic or predictive response markers. By screening a library of kinase siRNAs in combination with a subcytotoxic dose of ONC201, we identified several kinases that ablated tumor cell sensitivity, including the MAPK pathway-inducer KSR1. Unexpectedly, KSR1 silencing did not affect MAPK signaling in the presence or absence of ONC201, but instead reduced expression of the antiapoptotic proteins FLIP, Mcl-1, Bcl-2, cIAP1, cIAP2, and survivin. In parallel to this work, we also conducted a synergy screen in which ONC201 was combined with approved small-molecule anticancer drugs. In multiple cancer cell populations, ONC201 synergized with diverse drug classes, including the multikinase inhibitor sorafenib. Notably, combining ONC201 and sorafenib led to synergistic induction of TRAIL and its receptor DR5 along with a potent induction of cell death. In a mouse xenograft model of hepatocellular carcinoma, we demonstrated that ONC201 and sorafenib cooperatively and safely triggered tumor regressions. Overall, our results established a set of determinants for ONC201 sensitivity that may predict therapeutic response, particularly in settings of sorafenib cotreatment to enhance anticancer responses. ©2015 American Association for Cancer Research.
Molecular analysis of the iap gene of Listeria monocytogenes isolated from cheeses in Rio Grande do Sul, Brazil Análise molecular do gene iap de Listeria monocytogenes isoladas de queijos no Estado do Rio Grande do Sul, Brasil

Directory of Open Access Journals (Sweden)

Jozi Fagundes de Mello

2008-03-01

Full Text Available The polymorphic region sequences in the iap gene were analyzed in 25 strains of Listeria monocytogenes isolated from cheeses in the state of Rio Grande do Sul, and compared with reference strains. This investigation distinguished two clusters of L. monocytogenes: I (20 strains and II (5 strains.A seqüência da região polimórfica do gene iap foi analisada em 25 cepas de Listeria monocytogenes isoladas de queijo no Estado do Rio Grande do Sul e comparadas com cepas referências. Esta investigação distinguiu L. monocytogenes em dois grupos: I (20 cepas e II (5 cepas.
SOLO: a meiotic protein required for centromere cohesion, coorientation, and SMC1 localization in Drosophila melanogaster.

Science.gov (United States)

Yan, Rihui; Thomas, Sharon E; Tsai, Jui-He; Yamada, Yukihiro; McKee, Bruce D

2010-02-08

Sister chromatid cohesion is essential to maintain stable connections between homologues and sister chromatids during meiosis and to establish correct centromere orientation patterns on the meiosis I and II spindles. However, the meiotic cohesion apparatus in Drosophila melanogaster remains largely uncharacterized. We describe a novel protein, sisters on the loose (SOLO), which is essential for meiotic cohesion in Drosophila. In solo mutants, sister centromeres separate before prometaphase I, disrupting meiosis I centromere orientation and causing nondisjunction of both homologous and sister chromatids. Centromeric foci of the cohesin protein SMC1 are absent in solo mutants at all meiotic stages. SOLO and SMC1 colocalize to meiotic centromeres from early prophase I until anaphase II in wild-type males, but both proteins disappear prematurely at anaphase I in mutants for mei-S332, which encodes the Drosophila homologue of the cohesin protector protein shugoshin. The solo mutant phenotypes and the localization patterns of SOLO and SMC1 indicate that they function together to maintain sister chromatid cohesion in Drosophila meiosis.
Adaptación española del "International Affective Picture System" (IAPS: tercera parte

Directory of Open Access Journals (Sweden)

Javier Moltó

2013-10-01

Full Text Available Este trabajo proporciona los valores normativos españoles de las 358 imágenes que forman los conjuntos 15 a 20 del International Affective Picture System (IAPS. En este estudio participaron 811 estudiantes universitarios (521 mujeres que evaluaron las imágenes en las dimensiones emocionales de valencia, activación y dominancia. Las correlaciones entre las evaluaciones estadounidenses y las españolas en todas las dimensiones fueron altamente significativas y, como en Estados Unidos, la distribución de las imágenes en el espacio bidimensional afectivo definido por las dimensiones de valencia y activación adoptó la típica forma de boomerang. Los resultados confirmaron, asimismo, las diferencias de género encontradas en Estados Unidos en las evaluaciones de las imágenes aversivas. Estos resultados son totalmente consistentes con los obtenidos en la primera y segunda parte de la adaptación española, y demuestran que la estandarización del IAPS en nuestro país ha sido adecuada. Por último, se ratificaron las pequeñas diferencias transculturales encontradas en las evaluaciones de activación y dominancia: los españoles tendieron a asignar a las imágenes mayores puntuaciones en activación y menores en dominancia que los estadounidenses. Estos datos apoyan los estereotipos culturales de estos países y sugieren que el IAPS podría ser un indicador fiable de diferencias transculturales en la disposición emocional.
Polytene chromosomes of monogenic and amphogenic Chrysomya species (Calliphoridae, Diptera): analysis of banding patterns and in situ hybridization with Drosophila sex determining gene sequences.

Science.gov (United States)

Puchalla, S

1994-03-01

Standard maps for the five banded polytene chromosomes found in trichogen cell nuclei of the monogenic blowfly Chrysomya rufifacies and the amphogenic Chrysomya pinguis are presented. The chromosomes are highly homologous in the two species; differences in banding patterns are predominantly caused by one pericentric and ten paracentric inversions. In chromosome 5 of the amphogenic Chrysomya phaonis, also analysed in this paper, an additional paracentric inversion was observed. The distribution of species specific inversions indicates that the monogenic C. rufifacies is phylogenetically older than the amphogenic species. The maternal sex realizer locus F'/f on polytene chromosome 5 of C. rufifacies is not associated with a structural heterozygosity. Chromosome pair 6 of C. rufifacies and the sex chromosome pair of C. pinguis are under-replicated in polytene nuclei; they consist of irregular chromatin granules, frequently associated with nucleolus material. Evolution of heteromorphic sex chromosomes in Chrysomya is probably correlated with heterochromatin accumulation. A search for sex determining genes in Chrysomya was initiated using sex determining sequences from Drosophila melanogaster for in situ hybridization. The polytene band 41A1 on chromosome 5 of monogenic and amphogenic Chrysomya species contains sequences homologous to the maternal sex determining gene daughterless (da). Homology to the zygotic gene Sex-lethal (Sxl) of Drosophila is detected in band 39A1 on chromosome 5 of C. rufifacies. The findings reported here are the first evidence for a possible homology between the da gene of Drosophila and the maternal sex realizer F' of C. rufifacies. An hypothesis for the evolution of the maternal effect sex determination of C. rufifacies is proposed.
Tissue-specific regulation of BMP signaling by Drosophila N-glycanase 1.

Science.gov (United States)

Galeone, Antonio; Han, Seung Yeop; Huang, Chengcheng; Hosomi, Akira; Suzuki, Tadashi; Jafar-Nejad, Hamed

2017-08-04

Mutations in the human N- glycanase 1 ( NGLY1 ) cause a rare, multisystem congenital disorder with global developmental delay. However, the mechanisms by which NGLY1 and its homologs regulate embryonic development are not known. Here we show that Drosophila Pngl encodes an N -glycanase and exhibits a high degree of functional conservation with human NGLY1. Loss of Pngl results in developmental midgut defects reminiscent of midgut-specific loss of BMP signaling. Pngl mutant larvae also exhibit a severe midgut clearance defect, which cannot be fully explained by impaired BMP signaling. Genetic experiments indicate that Pngl is primarily required in the mesoderm during Drosophila development. Loss of Pngl results in a severe decrease in the level of Dpp homodimers and abolishes BMP autoregulation in the visceral mesoderm mediated by Dpp and Tkv homodimers. Thus, our studies uncover a novel mechanism for the tissue-specific regulation of an evolutionarily conserved signaling pathway by an N -glycanase enzyme.
Evaluation of Off-season Potential Breeding Sources for Spotted Wing Drosophila (Drosophila suzukii Matsumura) in Michigan.

Science.gov (United States)

Bal, Harit K; Adams, Christopher; Grieshop, Matthew

2017-12-05

It has been suggested that fruit wastes including dropped and unharvested fruits, and fruit byproducts (i.e., pomace) found in fruit plantings and cideries or wine-making facilities could serve as potential off-season breeding sites for spotted wing Drosophila (Drosophila suzukii Matsumura (Diptera: Drosophilidae)). This idea, however, has yet to be widely tested. The goal of our study was to determine the potential of dropped fruit and fruit wastes as Fall spotted wing Drosophila breeding resources in Michigan, USA. Fruit waste samples were collected from 15 farms across the lower peninsula of Michigan and were evaluated for spotted wing Drosophila and other drosophilid emergence and used in host suitability bioassays. All of the dropped apples, pears, grapes, and raspberries and 40% of apple and 100% of grape fruit pomace evaluated were found to contain spotted wing Drosophila with the highest numbers collected from dropped grapes and pears. Greater spotted wing Drosophila recovery was found in fruit wastes at sites attached with cideries and wine-making facilities and with multiple cultivated fruit crops than sites with no cideries and only one crop. Females oviposited in raspberry, pear, apple, grape, apple pomace and grape pomace samples with the highest rates of reproduction in raspberries. Our results demonstrate that fruit wastes including dropped berry, pomme and stone fruits, as well as fruit compost may be important late season reproductive resources for spotted wing Drosophila. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres

Directory of Open Access Journals (Sweden)

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.
Drosophila DJ-1 decreases neural sensitivity to stress by negatively regulating Daxx-like protein through dFOXO.

Directory of Open Access Journals (Sweden)

Soojin Hwang

2013-04-01

Full Text Available DJ-1, a Parkinson's disease (PD-associated gene, has been shown to protect against oxidative stress in Drosophila. However, the molecular mechanism underlying oxidative stress-induced phenotypes, including apoptosis, locomotive defects, and lethality, in DJ-1-deficient flies is not fully understood. Here we showed that Daxx-like protein (DLP, a Drosophila homologue of the mammalian Death domain-associated protein (Daxx, was upregulated under oxidative stress conditions in the loss-of-function mutants of Drosophila DJ-1β, a Drosophila homologue of DJ-1. DLP overexpression induced apoptosis via the c-Jun N-terminal kinase (JNK/Drosophila forkhead box subgroup O (dFOXO pathway, whereas loss of DLP increased resistance to oxidative stress and UV irradiation. Moreover, the oxidative stress-induced phenotypes of DJ-1β mutants were dramatically rescued by DLP deficiency, suggesting that enhanced expression of DLP contributes to the DJ-1β mutant phenotypes. Interestingly, we found that dFOXO was required for the increase in DLP expression in DJ-1β mutants and that dFOXO activity was increased in the heads of DJ-1β mutants. In addition, subcellular localization of DLP appeared to be influenced by DJ-1 expression so that cytosolic DLP was increased in DJ-1β mutants. Similarly, in mammalian cells, Daxx translocation from the nucleus to the cytosol was suppressed by overexpressed DJ-1β under oxidative stress conditions; and, furthermore, targeted expression of DJ-1β to mitochondria efficiently inhibited the Daxx translocation. Taken together, our findings demonstrate that DJ-1β protects flies against oxidative stress- and UV-induced apoptosis by regulating the subcellular localization and gene expression of DLP, thus implying that Daxx-induced apoptosis is involved in the pathogenesis of DJ-1-associated PD.
Heavy metals effect in Drosophila melanogaster germinal cells

International Nuclear Information System (INIS)

Rosa Duque de la, M.E.

1984-01-01

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 y 2 wsup(a)/y 2 wsup(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)
Birth order dependent growth cone segregation determines synaptic layer identity in the Drosophila visual system.

Science.gov (United States)

Kulkarni, Abhishek; Ertekin, Deniz; Lee, Chi-Hon; Hummel, Thomas

2016-03-17

The precise recognition of appropriate synaptic partner neurons is a critical step during neural circuit assembly. However, little is known about the developmental context in which recognition specificity is important to establish synaptic contacts. We show that in the Drosophila visual system, sequential segregation of photoreceptor afferents, reflecting their birth order, lead to differential positioning of their growth cones in the early target region. By combining loss- and gain-of-function analyses we demonstrate that relative differences in the expression of the transcription factor Sequoia regulate R cell growth cone segregation. This initial growth cone positioning is consolidated via cell-adhesion molecule Capricious in R8 axons. Further, we show that the initial growth cone positioning determines synaptic layer selection through proximity-based axon-target interactions. Taken together, we demonstrate that birth order dependent pre-patterning of afferent growth cones is an essential pre-requisite for the identification of synaptic partner neurons during visual map formation in Drosophila.
IAP antagonists Birinapant and AT-406 efficiently synergise with either TRAIL, BRAF, or BCL-2 inhibitors to sensitise BRAFV600E colorectal tumour cells to apoptosis.

Science.gov (United States)

Perimenis, Philippos; Galaris, Apostolos; Voulgari, Alexandra; Prassa, Margarita; Pintzas, Alexander

2016-08-12

High expression levels of Inhibitors of Apoptosis Proteins (IAPs) have been correlated with poor cancer prognosis and block the cell death pathway by interfering with caspase activation. SMAC-mimetics are small-molecule inhibitors of IAPs that mimic the endogenous SMAC and promote the induction of cell death by neutralizing IAPs. In this study, anti-tumour activity of new SMAC-mimetics Birinapant and AT-406 is evaluated against colorectal adenocarcinoma cells and IAP cross-talk with either oncogenic BRAF or BCL-2, or with the TRAIL are further exploited towards rational combined protocols. It is shown that pre-treatment of SMAC-mimetics followed by their combined treatment with BRAF inhibitors can decrease cell viability, migration and can very efficiently sensitize colorectal tumour cells to apoptosis. Moreover, co-treatment of TRAIL with SMAC-mimetics can efficiently sensitize resistant tumour cells to apoptosis synergistically, as shown by median effect analysis. Finally, Birinapant and AT-406 can synergise with BCL-2 inhibitor ABT-199 to reduce viability of adenocarcinoma cells with high BCL-2 expression. Proposed synergistic rational anticancer combined protocols of IAP antagonists Birinapant and AT-406 in 2D and 3D cultures can be later further exploited in vivo, from precision tumour biology to precision medical oncology.
Genetic effects induced by neutrons in Drosophila melanogaster I. Determination of absorbed dose

International Nuclear Information System (INIS)

Delfin, A.; Paredes, L.C.; Zambrano, F.; Guzman-Rincon, J.; Urena-Nunez, F.

2001-01-01

A method to obtain the absorbed dose in Drosophila melanogaster irradiated in the thermal column facility of the Triga Mark III Reactor has been developed. The method is based on the measurements of neutron activation of gold foils produced by neutron capture to obtain the neutron fluxes. These fluxes, combined with the calculations of kinetic energy released per unit mass, enables one to obtain the absorbed doses in Drosophila melanogaster
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

The database of the Drosophila Genome Project contains the sequences of two genes, CG8784 and CG8795, predicted to code for two structurally related G protein-coupled receptors. We have cloned these genes and expressed their coding parts in Chinese hamster ovary cells. We found that both receptors...... can be activated by low concentrations of the Drosophila neuropeptide pyrokinin-2 (CG8784, EC(50) for pyrokinin-2, 1x10(-9)M; CG8795, EC(50) for pyrokinin-2, 5 x 10(-10)M). The precise role of Drosophila pyrokinin-2 (SVPFKPRLamide) in Drosophila is unknown, but in other insects, pyrokinins have...... 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...
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.
Heterologous expression of mammalian Plk1 in Drosophila reveals divergence from Polo during late mitosis

International Nuclear Information System (INIS)

Pearson, John; Godinho, Susana A.; Tavares, Alvaro; Glover, David M.

2006-01-01

Drosophila Polo kinase is the founder member of a conserved kinase family required for multiple stages of mitosis. We assessed the ability of mouse Polo-like kinase 1 (Plk1) to perform the multiple mitotic functions of Polo kinase, by expressing a Plk1-GFP fusion in Drosophila. Consistent with the previously reported localization of Polo kinase, Plk1-GFP was strongly localized to centrosomes and recruited to the centromeric regions of condensing chromosomes during early mitosis. However, in contrast to a functional Polo-GFP fusion, Plk1-GFP failed to localize to the central spindle midzone in both syncytial embryo mitosis and the conventional mitoses of cellularized embryos and S2 cells. Moreover, unlike endogenous Polo kinase and Polo-GFP, Plk1-GFP failed to associate with the contractile ring. Expression of Plk1-GFP enhanced the lethality of hypomorphic polo mutants and disrupted the organization of the actinomyosin cytoskeleton in a dominant-negative manner. Taken together, our results suggest that endogenous Polo kinase has specific roles in regulating actinomyosin rearrangements during Drosophila mitoses that its mammalian counterpart, Plk1, cannot fulfill. Consistent with this hypothesis, we observed defects in the cortical recruitment of myosin and myosin regulatory light chain in Polo deficient cells
Positive Selection Drives the Evolution of rhino, a Member of the Heterochromatin Protein 1 Family in Drosophila.

Directory of Open Access Journals (Sweden)

2005-07-01

Full Text Available Heterochromatin comprises a significant component of many eukaryotic genomes. In comparison to euchromatin, heterochromatin is gene poor, transposon rich, and late replicating. It serves many important biological roles, from gene silencing to accurate chromosome segregation, yet little is known about the evolutionary constraints that shape heterochromatin. A complementary approach to the traditional one of directly studying heterochromatic DNA sequence is to study the evolution of proteins that bind and define heterochromatin. One of the best markers for heterochromatin is the heterochromatin protein 1 (HP1, which is an essential, nonhistone chromosomal protein. Here we investigate the molecular evolution of five HP1 paralogs present in Drosophila melanogaster. Three of these paralogs have ubiquitous expression patterns in adult Drosophila tissues, whereas HP1D/rhino and HP1E are expressed predominantly in ovaries and testes respectively. The HP1 paralogs also have distinct localization preferences in Drosophila cells. Thus, Rhino localizes to the heterochromatic compartment in Drosophila tissue culture cells, but in a pattern distinct from HP1A and lysine-9 dimethylated H3. Using molecular evolution and population genetic analyses, we find that rhino has been subject to positive selection in all three domains of the protein: the N-terminal chromo domain, the C-terminal chromo-shadow domain, and the hinge region that connects these two modules. Maximum likelihood analysis of rhino sequences from 20 species of Drosophila reveals that a small number of residues of the chromo and shadow domains have been subject to repeated positive selection. The rapid and positive selection of rhino is highly unusual for a gene encoding a chromosomal protein and suggests that rhino is involved in a genetic conflict that affects the germline, belying the notion that heterochromatin is simply a passive recipient of "junk DNA" in eukaryotic genomes.

Positive selection drives the evolution of rhino, a member of the heterochromatin protein 1 family in Drosophila.

Directory of Open Access Journals (Sweden)

Danielle Vermaak

2005-07-01

Full Text Available Heterochromatin comprises a significant component of many eukaryotic genomes. In comparison to euchromatin, heterochromatin is gene poor, transposon rich, and late replicating. It serves many important biological roles, from gene silencing to accurate chromosome segregation, yet little is known about the evolutionary constraints that shape heterochromatin. A complementary approach to the traditional one of directly studying heterochromatic DNA sequence is to study the evolution of proteins that bind and define heterochromatin. One of the best markers for heterochromatin is the heterochromatin protein 1 (HP1, which is an essential, nonhistone chromosomal protein. Here we investigate the molecular evolution of five HP1 paralogs present in Drosophila melanogaster. Three of these paralogs have ubiquitous expression patterns in adult Drosophila tissues, whereas HP1D/rhino and HP1E are expressed predominantly in ovaries and testes respectively. The HP1 paralogs also have distinct localization preferences in Drosophila cells. Thus, Rhino localizes to the heterochromatic compartment in Drosophila tissue culture cells, but in a pattern distinct from HP1A and lysine-9 dimethylated H3. Using molecular evolution and population genetic analyses, we find that rhino has been subject to positive selection in all three domains of the protein: the N-terminal chromo domain, the C-terminal chromo-shadow domain, and the hinge region that connects these two modules. Maximum likelihood analysis of rhino sequences from 20 species of Drosophila reveals that a small number of residues of the chromo and shadow domains have been subject to repeated positive selection. The rapid and positive selection of rhino is highly unusual for a gene encoding a chromosomal protein and suggests that rhino is involved in a genetic conflict that affects the germline, belying the notion that heterochromatin is simply a passive recipient of "junk DNA" in eukaryotic genomes.
Drosophila as a model for the study of sex determination in anopheline and aedine mosquitoes

International Nuclear Information System (INIS)

Pannuti, A.; Kocacitak, T.; Lucchesi, J.C.

2000-01-01

Sterile insect technique control strategies consist of releasing laboratory produced male insects that have been sterilised by irradiation. These strategies require the production of massive quantities of males. Population-replacement strategies rely on the genetically engineered interruption of that portion of the malaria parasite's life cycle that occurs in the mosquito. This could be achieved by the inundative introduction of transformed males or the more limited introduction of males carrying an infective agent capable of driving a parasite-inhibiting transgene into the vector population. Once again, the release of genetically engineered males would require genetic systems for their mass production. Mass production of males can be accomplished most effectively through genetic sexing techniques. Genetic sexing can be achieved by identifying the key steps in the genetic regulation of sex differentiation and by modifying one or more of these steps so that their execution would result in sex-specific lethality. As the necessary and seminal first step towards this goal, we set out to identify and isolate a gene whose primary transcript is processed differently in males and females of Anopheles gambiae Giles. A survey of sex determination among insects reveals a vast array of different mechanisms. Our understanding of these mechanisms consists only of information derived from classical cytological and genetic studies. Using the knowledge derived from the study of Drosophila, it has been possible to discern a fundamental pattern in the sex determining mechanisms of many diverse insect species (Noethiger and Steinmann-Zwicky 1985). The challenge now, is to determine if there has been an evolutionary conservation of the genes responsible for the fundamental pattern, i.e., if the molecular mechanisms that underlie sex determination in Drosophila are the same in other insects of interest or if in these insects, the apparent fundamental pattern is achieved by completely
Impact of the Chromatin Remodeling Factor CHD1 on Gut Microbiome Composition of Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Johanna Sebald

Full Text Available The composition of the intestinal microbiota of Drosophila has been studied in some detail in recent years. Environmental, developmental and host-specific genetic factors influence microbiome composition in the fly. Our previous work has indicated that intestinal bacterial load can be affected by chromatin-targeted regulatory mechanisms. Here we studied a potential role of the conserved chromatin assembly and remodeling factor CHD1 in the shaping of the gut microbiome in Drosophila melanogaster. Using high-throughput sequencing of 16S rRNA gene amplicons, we found that Chd1 deletion mutant flies exhibit significantly reduced microbial diversity compared to rescued control strains. Specifically, although Acetobacteraceae dominated the microbiota of both Chd1 wild-type and mutant guts, Chd1 mutants were virtually monoassociated with this bacterial family, whereas in control flies other bacterial taxa constituted ~20% of the microbiome. We further show age-linked differences in microbial load and microbiota composition between Chd1 mutant and control flies. Finally, diet supplementation experiments with Lactobacillus plantarum revealed that, in contrast to wild-type flies, Chd1 mutant flies were unable to maintain higher L. plantarum titres over time. Collectively, these data provide evidence that loss of the chromatin remodeler CHD1 has a major impact on the gut microbiome of Drosophila melanogaster.
The influence of sterol metabolism upon radiation-induced aneuploidy of Drosophila melanogaster in the yeast-drosophila system

International Nuclear Information System (INIS)

Savitsij, V.V.; Luchnikova, E.M.; Inge-Vechtomov, S.I.

1985-01-01

The influence of sterol metabolism upon induced Drosophila melanogaster mutagenesis in an ecology-genetic yeast-drosophila system has been studied. The sterol deficit in fly organism has been created for account of using as food substrate for fremales of biomass of saccharomyces cerevisiae living cells of 9-2-PZ12 train with nyssup(r1) locus mutation which blocks the ergosterol synthesis. It has been found that the Drosophila females content on mutant yeast increases the frequency of losses and non discrepancy of X-chromosomes induced by X-radiation (1000 R). Addition into yeast biomass of 0.1 % cholesterol solution in 10 %-ethanol reduces the oocytes resistance to X-radiation up to control level. Possible hormonal and membrane mechanisms of increasing radiation-induced aneuploidy of Drosophila and the role of sterol metabolism in organism resistance to damaging factors are discussed
Drosophila melanogaster Mounts a Unique Immune Response to the Rhabdovirus Sigma virus▿

Science.gov (United States)

Tsai, C. W.; McGraw, E. A.; Ammar, E.-D.; Dietzgen, R. G.; Hogenhout, S. A.

2008-01-01

Rhabdoviruses are important pathogens of humans, livestock, and plants that are often vectored by insects. Rhabdovirus particles have a characteristic bullet shape with a lipid envelope and surface-exposed transmembrane glycoproteins. Sigma virus (SIGMAV) is a member of the Rhabdoviridae and is a naturally occurring disease agent of Drosophila melanogaster. The infection is maintained in Drosophila populations through vertical transmission via germ cells. We report here the nature of the Drosophila innate immune response to SIGMAV infection as revealed by quantitative reverse transcription-PCR analysis of differentially expressed genes identified by microarray analysis. We have also compared and contrasted the immune response of the host with respect to two nonenveloped viruses, Drosophila C virus (DCV) and Drosophila X virus (DXV). We determined that SIGMAV infection upregulates expression of the peptidoglycan receptor protein genes PGRP-SB1 and PGRP-SD and the antimicrobial peptide (AMP) genes Diptericin-A, Attacin-A, Attacin-B, Cecropin-A1, and Drosocin. SIGMAV infection did not induce PGRP-SA and the AMP genes Drosomycin-B, Metchnikowin, and Defensin that are upregulated in DCV and/or DXV infections. Expression levels of the Toll and Imd signaling cascade genes are not significantly altered by SIGMAV infection. These results highlight shared and unique aspects of the Drosophila immune response to the three viruses and may shed light on the nature of the interaction with the host and the evolution of these associations. PMID:18378641
Org-1-dependent lineage reprogramming generates the ventral longitudinal musculature of the Drosophila heart.

Science.gov (United States)

Schaub, Christoph; März, Johannes; Reim, Ingolf; Frasch, Manfred

2015-02-16

Only few examples of transdifferentiation, which denotes the conversion of one differentiated cell type to another, are known to occur during normal development, and more often, it is associated with regeneration processes. With respect to muscles, dedifferentiation/redifferentiation processes have been documented during post-traumatic muscle regeneration in blastema of newts as well as during myocardial regeneration. As shown herein, the ventral longitudinal muscles of the adult Drosophila heart arise from specific larval alary muscles in a process that represents the first known example of syncytial muscle transdifferentiation via dedifferentiation into mononucleate myoblasts during normal development. We demonstrate that this unique process depends on the reinitiation of a transcriptional program previously employed for embryonic alary muscle development, in which the factors Org-1 (Drosophila Tbx1) and Tailup (Drosophila Islet1) are key components. During metamorphosis, the action of these factors is combined with cell-autonomous inputs from the ecdysone steroid and the Hox gene Ultrabithorax, which provide temporal and spatial specificity to the transdifferentiation events. Following muscle dedifferentiation, inductive cues, particularly from the remodeling heart tube, are required for the redifferentiation of myoblasts into ventral longitudinal muscles. Our results provide new insights into mechanisms of lineage commitment and cell-fate plasticity during development. Copyright © 2015 Elsevier Ltd. All rights reserved.
Ire1 mediated mRNA splicing in a C-terminus deletion mutant of Drosophila Xbp1.

Directory of Open Access Journals (Sweden)

Dina S Coelho

Full Text Available The Unfolded Protein Response is a homeostatic mechanism that permits eukaryotic cells to cope with Endoplasmic Reticulum (ER stress caused by excessive accumulation of misfolded proteins in the ER lumen. The more conserved branch of the UPR relies on an ER transmembrane enzyme, Ire1, which, upon ER stress, promotes the unconventional splicing of a small intron from the mRNA encoding the transcription factor Xbp1. In mammals, two specific regions (the hydrophobic region 2--HR2--and the C-terminal translational pausing site present in the Xbp1unspliced protein mediate the recruitment of the Xbp1 mRNA-ribosome-nascent chain complex to the ER membrane, so that Xbp1 mRNA can be spliced by Ire1. Here, we generated a Drosophila Xbp1 deletion mutant (Excision101 lacking both HR2 and C-terminal region, but not the Ire1 splicing site. We show that Ire1-dependent splicing of Xbp1 mRNA is reduced, but not abolished in Excision101. Our results suggest the existence of additional mechanisms for ER membrane targeting of Xbp1 mRNA that are independent of the C-terminal domain of Drosophila Xbp1unspliced.
Determination of gene expression patterns using high-throughput RNA in situ hybridizaion to whole-mount Drosophila embryos

Energy Technology Data Exchange (ETDEWEB)

Weiszmann, R.; Hammonds, A.S.; Celniker, S.E.

2009-04-09

We describe a high-throughput protocol for RNA in situ hybridization (ISH) to Drosophila embryos in a 96-well format. cDNA or genomic DNA templates are amplified by PCR and then digoxigenin-labeled ribonucleotides are incorporated into antisense RNA probes by in vitro transcription. The quality of each probe is evaluated before ISH using a RNA probe quantification (dot blot) assay. RNA probes are hybridized to fixed, mixed-staged Drosophila embryos in 96-well plates. The resulting stained embryos can be examined and photographed immediately or stored at 4oC for later analysis. Starting with fixed, staged embryos, the protocol takes 6 d from probe template production through hybridization. Preparation of fixed embryos requires a minimum of 2 weeks to collect embryos representing all stages. The method has been used to determine the expression patterns of over 6,000 genes throughout embryogenesis.
Definition of a RACK1 Interaction Network in Drosophila melanogaster Using SWATH-MS.

Science.gov (United States)

Kuhn, Lauriane; Majzoub, Karim; Einhorn, Evelyne; Chicher, Johana; Pompon, Julien; Imler, Jean-Luc; Hammann, Philippe; Meignin, Carine

2017-07-05

Receptor for Activated protein C kinase 1 (RACK1) is a scaffold protein that has been found in association with several signaling complexes, and with the 40S subunit of the ribosome. Using the model organism Drosophila melanogaster , we recently showed that RACK1 is required at the ribosome for internal ribosome entry site (IRES)-mediated translation of viruses. Here, we report a proteomic characterization of the interactome of RACK1 in Drosophila S2 cells. We carried out Label-Free quantitation using both Data-Dependent and Data-Independent Acquisition (DDA and DIA, respectively) and observed a significant advantage for the Sequential Window Acquisition of all THeoretical fragment-ion spectra (SWATH) method, both in terms of identification of interactants and quantification of low abundance proteins. These data represent the first SWATH spectral library available for Drosophila and will be a useful resource for the community. A total of 52 interacting proteins were identified, including several molecules involved in translation such as structural components of the ribosome, factors regulating translation initiation or elongation, and RNA binding proteins. Among these 52 proteins, 15 were identified as partners by the SWATH strategy only. Interestingly, these 15 proteins are significantly enriched for the functions translation and nucleic acid binding. This enrichment reflects the engagement of RACK1 at the ribosome and highlights the added value of SWATH analysis. A functional screen did not reveal any protein sharing the interesting properties of RACK1, which is required for IRES-dependent translation and not essential for cell viability. Intriguingly however, 10 of the RACK1 partners identified restrict replication of Cricket paralysis virus (CrPV), an IRES-containing virus. Copyright © 2017 Kuhn et al.
Molecular genetics of rhodopsin and phototrans duction in the visual system of Drosophila

International Nuclear Information System (INIS)

Zuker, C.; Cowman, A.; Montell, C.; Rubin, G.

1987-01-01

The authors have isolated the genes encoding four Drosophila visual pigments. Each of these opsins is expressed in a set of functionally and anatomically distinct photoreceptor cells of the eye. One is expressed in the six outer photoreceptor cells (R1-R6), the second in the central R8 photoreceptor cell, and the other two in the UV sensitive R7 photoreceptor cells. They have determined the structure and nucleotide sequence of each of these genes. They have used P element-mediated gene transfer to introduce the cloned structural gene for the R1-R6 opsin in the Drosophila germline and restored the ninaE mutant phenotype to wild-type. In an attempt to study the contribution of the various opsins to the specific functional properties of the different photoreceptor cell types, they have genetically engineered Drosophila lines that express R8 opsin in the R1-R6 photoreceptor cells. In collaboration with Drs. Ozaki and Pak at Purdue University, they have used oligonucleotide site-directed mutagenesis to mutate selected amino acids and regions of the rhodopsin molecule and reintroduced the mutated genes into Drosophila to analyze structure-function relationships in the rhodopsin molecule
viking: identification and characterization of a second type IV collagen in Drosophila.

Science.gov (United States)

Yasothornsrikul, S; Davis, W J; Cramer, G; Kimbrell, D A; Dearolf, C R

1997-10-01

We have taken an enhancer trap approach to identify genes that are expressed in hematopoietic cells and tissues of Drosophila. We conducted a molecular analysis of two P-element insertion strains that have reporter gene expression in embryonic hemocytes, strain 197 and vikingICO. This analysis has determined that viking encodes a collagen type IV gene, alpha2(IV). The viking locus is located adjacent to the previously described DCg1, which encodes collagen alpha1(IV), and in the opposite orientation. The alpha2(IV) and alpha1(IV) collagens are structurally very similar to one another, and to vertebrate type IV collagens. In early development, viking and DCg1 are transcribed in the same tissue-specific pattern, primarily in the hemocytes and fat body cells. Our results suggest that both the alpha1 and alpha2 collagen IV chains may contribute to basement membranes in Drosophila. This work also provides the foundation for a more complete genetic dissection of collagen type IV molecules and their developmental function in Drosophila.
Parameter estimation and determinability analysis applied to Drosophila gap gene circuits

Directory of Open Access Journals (Sweden)

Jaeger Johannes

2008-09-01

Full Text Available Abstract Background Mathematical modeling of real-life processes often requires the estimation of unknown parameters. Once the parameters are found by means of optimization, it is important to assess the quality of the parameter estimates, especially if parameter values are used to draw biological conclusions from the model. Results In this paper we describe how the quality of parameter estimates can be analyzed. We apply our methodology to assess parameter determinability for gene circuit models of the gap gene network in early Drosophila embryos. Conclusion Our analysis shows that none of the parameters of the considered model can be determined individually with reasonable accuracy due to correlations between parameters. Therefore, the model cannot be used as a tool to infer quantitative regulatory weights. On the other hand, our results show that it is still possible to draw reliable qualitative conclusions on the regulatory topology of the gene network. Moreover, it improves previous analyses of the same model by allowing us to identify those interactions for which qualitative conclusions are reliable, and those for which they are ambiguous.
Mutagenic effect of tritium on DNA of Drosophila melanogaster. Comprehensive performance report, December 15, 1985-June 1, 1988

International Nuclear Information System (INIS)

Lee, W.R.

1988-01-01

The results of the RBE determination of tritium to cobalt-69 gamma radiation along with a description of methods of treatment and dose determination are given. Using the described procedures for exposing Drosophila to tritiated water, the authors induced mutations by tritium beta radiation and recovered them at the Adh locus
Scavenger receptors mediate the role of SUMO and Ftz-f1 in Drosophila steroidogenesis.

Directory of Open Access Journals (Sweden)

Ana Talamillo

2013-04-01

Full Text Available SUMOylation participates in ecdysteroid biosynthesis at the onset of metamorphosis in Drosophila melanogaster. Silencing the Drosophila SUMO homologue smt3 in the prothoracic gland leads to reduced lipid content, low ecdysone titers, and a block in the larval-pupal transition. Here we show that the SR-BI family of Scavenger Receptors mediates SUMO functions. Reduced levels of Snmp1 compromise lipid uptake in the prothoracic gland. In addition, overexpression of Snmp1 is able to recover lipid droplet levels in the smt3 knockdown prothoracic gland cells. Snmp1 expression depends on Ftz-f1 (an NR5A-type orphan nuclear receptor, the expression of which, in turn, depends on SUMO. Furthermore, we show by in vitro and in vivo experiments that Ftz-f1 is SUMOylated. RNAi-mediated knockdown of ftz-f1 phenocopies that of smt3 at the larval to pupal transition, thus Ftz-f1 is an interesting candidate to mediate some of the functions of SUMO at the onset of metamorphosis. Additionally, we demonstrate that the role of SUMOylation, Ftz-f1, and the Scavenger Receptors in lipid capture and mobilization is conserved in other steroidogenic tissues such as the follicle cells of the ovary. smt3 knockdown, as well as ftz-f1 or Scavenger knockdown, depleted the lipid content of the follicle cells, which could be rescued by Snmp1 overexpression. Therefore, our data provide new insights into the regulation of metamorphosis via lipid homeostasis, showing that Drosophila Smt3, Ftz-f1, and SR-BIs are part of a general mechanism for uptake of lipids such as cholesterol, required during development in steroidogenic tissues.
The silent information regulator 1 (Sirt1) is a positive regulator of the Notch pathway in Drosophila

Czech Academy of Sciences Publication Activity Database

Horváth, Matěj; Mihajlović, Zorana; Slaninová, Věra; Perez-Gomez, Raquel; Moshkin, Y.; Krejčí, Alena

2016-01-01

Roč. 473, č. 22 (2016), s. 4129-4143 ISSN 0264-6021 R&D Projects: GA ČR(CZ) GA14-08583S Institutional support: RVO:60077344 Keywords : Drosophila * silent information regulator 1 * Notch pathway Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.797, year: 2016
Tumor suppressor roles of CENP-E and Nsl1 in Drosophila epithelial tissues.

Science.gov (United States)

Clemente-Ruiz, Marta; Muzzopappa, Mariana; Milán, Marco

2014-01-01

Depletion of spindle assembly checkpoint (SAC) genes in Drosophila epithelial tissues leads to JNK-dependent programmed cell death and additional blockade of the apoptotic program drives tumorigenesis. A recent report proposes that chromosomal instability (CIN) is not the driving force in the tumorigenic response of the SAC-deficient tissue, and that checkpoint proteins exert a SAC-independent tumor suppressor role. This notion is based on observations that the depletion of CENP-E levels or prevention of Bub3 from binding to the kinetochore in Drosophila tissues unable to activate the apoptotic program induces CIN but does not cause hyperproliferation. Here we re-examined this proposal. In contrast to the previous report, we observed that depletion of CENP-E or Nsl1-the latter mediating kinetochore targeting of Bub3-in epithelial tissues unable to activate the apoptotic program induces significant levels of aneuploidy and drives tumor-like growth. The induction of the JNK transcriptional targets Wingless, a mitogenic molecule, and MMP1, a matrix metaloproteinase 1 involved in basement membrane degradation was also observed in these tumors. An identical response of the tissue was previously detected upon depletion of several SAC genes or genes involved in spindle assembly, chromatin condensation, and cytokinesis, all of which have been described to cause CIN. All together, these results reinforce the role of CIN in driving tumorigenesis in Drosophila epithelial tissues and question the proposed SAC-independent roles of checkpoint proteins in suppressing tumorigenesis. Differences in aneuploidy rates might explain the discrepancy between the previous report and our results.
Drosophila atm/telomere fusion is required for telomeric localization of HP1 and telomere position effect.

Science.gov (United States)

Oikemus, Sarah R; McGinnis, Nadine; Queiroz-Machado, Joana; Tukachinsky, Hanna; Takada, Saeko; Sunkel, Claudio E; Brodsky, Michael H

2004-08-01

Terminal deletions of Drosophila chromosomes can be stably protected from end-to-end fusion despite the absence of all telomere-associated sequences. The sequence-independent protection of these telomeres suggests that recognition of chromosome ends might contribute to the epigenetic protection of telomeres. In mammals, Ataxia Telangiectasia Mutated (ATM) is activated by DNA damage and acts through an unknown, telomerase-independent mechanism to regulate telomere length and protection. We demonstrate that the Drosophila homolog of ATM is encoded by the telomere fusion (tefu) gene. In the absence of ATM, telomere fusions occur even though telomere-specific Het-A sequences are still present. High levels of spontaneous apoptosis are observed in ATM-deficient tissues, indicating that telomere dysfunction induces apoptosis in Drosophila. Suppression of this apoptosis by p53 mutations suggests that loss of ATM activates apoptosis through a DNA damage-response mechanism. Loss of ATM reduces the levels of heterochromatin protein 1 (HP1) at telomeres and suppresses telomere position effect. We propose that recognition of chromosome ends by ATM prevents telomere fusion and apoptosis by recruiting chromatin-modifying complexes to telomeres.
Behavioral Teratogenesis in Drosophila melanogaster.

Science.gov (United States)

Mishra, Monalisa; Barik, Bedanta Kumar

2018-01-01

Developmental biology is a fascinating branch of science which helps us to understand the mechanism of development, thus the findings are used in various therapeutic approach. Drosophila melanogaster served as a model to find the key molecules that initiate and regulate the mechanism of development. Various genes, transcription factors, and signaling pathways helping in development are identified in Drosophila. Many toxic compounds, which can affect the development, are also recognized using Drosophila model. These compounds, which can affect the development, are named as a teratogen. Many teratogens identified using Drosophila may also act as a teratogen for a human being since 75% of conservation exist between the disease genes present in Drosophila and human. There are certain teratogens, which do not cause developmental defect if exposed during pregnancy, however; behavioral defect appears in later part of development. Such compounds are named as a behavioral teratogen. Thus, it is worthy to identify the potential behavioral teratogen using Drosophila model. Drosophila behavior is well studied in various developmental stages. This chapter describes various methods which can be employed to test behavioral teratogenesis in Drosophila.
Drosophila TRPA1 isoforms detect UV light via photochemical production of H2O2

Science.gov (United States)

Guntur, Ananya R.; Gu, Pengyu; Takle, Kendra; Chen, Jingyi; Xiang, Yang; Yang, Chung-Hui

2015-01-01

The transient receptor potential A1 (TRPA1) channel is an evolutionarily conserved detector of temperature and irritant chemicals. Here, we show that two specific isoforms of TRPA1 in Drosophila are H2O2 sensitive and that they can detect strong UV light via sensing light-induced production of H2O2. We found that ectopic expression of these H2O2-sensitive Drosophila TRPA1 (dTRPA1) isoforms conferred UV sensitivity to light-insensitive HEK293 cells and Drosophila neurons, whereas expressing the H2O2-insensitive isoform did not. Curiously, when expressed in one specific group of motor neurons in adult flies, the H2O2-sensitive dTRPA1 isoforms were as competent as the blue light-gated channelrhodopsin-2 in triggering motor output in response to light. We found that the corpus cardiacum (CC) cells, a group of neuroendocrine cells that produce the adipokinetic hormone (AKH) in the larval ring gland endogenously express these H2O2-sensitive dTRPA1 isoforms and that they are UV sensitive. Sensitivity of CC cells required dTRPA1 and H2O2 production but not conventional phototransduction molecules. Our results suggest that specific isoforms of dTRPA1 can sense UV light via photochemical production of H2O2. We speculate that UV sensitivity conferred by these isoforms in CC cells may allow young larvae to activate stress response—a function of CC cells—when they encounter strong UV, an aversive stimulus for young larvae. PMID:26443856
Distribution of DNA replication proteins in Drosophila cells

Science.gov (United States)

Easwaran, Hariharan P; Leonhardt, Heinrich; Cardoso, M Cristina

2007-01-01

Background DNA replication in higher eukaryotic cells is organized in discrete subnuclear sites called replication foci (RF). During the S phase, most replication proteins assemble at the RF by interacting with PCNA via a PCNA binding domain (PBD). This has been shown to occur for many mammalian replication proteins, but it is not known whether this mechanism is conserved in evolution. Results Fluorescent fusions of mammalian replication proteins, Dnmt1, HsDNA Lig I and HsPCNA were analyzed for their ability to target to RF in Drosophila cells. Except for HsPCNA, none of the other proteins and their deletions showed any accumulation at RF in Drosophila cells. We hypothesized that in Drosophila cells there might be some other peptide sequence responsible for targeting proteins to RF. To test this, we identified the DmDNA Lig I and compared the protein sequence with HsDNA Lig I. The two orthologs shared the PBD suggesting a functionally conserved role for this domain in the Drosophila counterpart. A series of deletions of DmDNA Lig I were analyzed for their ability to accumulate at RF in Drosophila and mammalian cells. Surprisingly, no accumulation at RF was observed in Drosophila cells, while in mammalian cells DmDNA Lig I accumulated at RF via its PBD. Further, GFP fusions with the PBD domains from Dnmt1, HsDNA Lig I and DmDNA Lig I, were able to target to RF only in mammalian cells but not in Drosophila cells. Conclusion We show that S phase in Drosophila cells is characterized by formation of RF marked by PCNA like in mammalian cells. However, other than PCNA none of the replication proteins and their deletions tested here showed accumulation at RF in Drosophila cells while the same proteins and deletions are capable of accumulating at RF in mammalian cells. We hypothesize that unlike mammalian cells, in Drosophila cells, replication proteins do not form long-lasting interactions with the replication machinery, and rather perform their functions via very

Physiologically based pharmacokinetic and pharmacodynamic modeling of an antagonist (SM-406/AT-406) of multiple inhibitor of apoptosis proteins (IAPs) in a mouse xenograft model of human breast cancer.

Science.gov (United States)

Zhang, Tao; Li, Yanyan; Zou, Peng; Yu, Jing-yu; McEachern, Donna; Wang, Shaomeng; Sun, Duxin

2013-09-01

The inhibitors of apoptosis proteins (IAPs) are a class of key apoptosis regulators overexpressed or dysregulated in cancer. SM-406/AT-406 is a potent and selective small molecule mimetic of Smac that antagonizes the inhibitor of apoptosis proteins (IAPs). A physiologically based pharmacokinetic and pharmacodynamic (PBPK-PD) model was developed to predict the tissue concentration-time profiles of SM-406, the related onco-protein levels in tumor, and the tumor growth inhibition in a mouse model bearing human breast cancer xenograft. In the whole body physiologically based pharmacokinetic (PBPK) model for pharmacokinetics characterization, a well stirred (perfusion rate-limited) model was used to describe SM-406 pharmacokinetics in the lung, heart, kidney, intestine, liver and spleen, and a diffusion rate-limited (permeability limited) model was used for tumor. Pharmacodynamic (PD) models were developed to correlate the SM-406 concentration in tumor to the cIAP1 degradation, pro-caspase 8 decrease, CL-PARP accumulation and tumor growth inhibition. The PBPK-PD model well described the experimental pharmacokinetic data, the pharmacodynamic biomarker responses and tumor growth. This model may be helpful to predict tumor and plasma SM-406 concentrations in the clinic. Copyright © 2013 John Wiley & Sons, Ltd.
Characterization of a Smad motif similar to Drosophila mad in the mouse Msx 1 promoter.

Science.gov (United States)

Alvarez Martinez, Cristina E; Binato, Renata; Gonzalez, Sayonara; Pereira, Monica; Robert, Benoit; Abdelhay, Eliana

2002-03-01

Mouse Msx 1 gene, orthologous of the Drosophila msh, is involved in several developmental processes. BMP family members are major proteins in the regulation of Msx 1 expression. BMP signaling activates Smad 1/5/8 proteins, which associate to Smad 4 before translocating to the nucleus. Analysis of Msx 1 promoter revealed the presence of three elements similar to the consensus established for Mad, the Smad 1 Drosophila counterpart. Notably, such an element was identified in an enhancer important for Msx 1 regulation. Gel shift analysis demonstrated that proteins from 13.5 dpc embryo associate to this enhancer. Remarkably, supershift assays showed that Smad proteins are present in the complex. Purified Smad 1 and 4 also bind to this fragment. We demonstrate that functional binding sites in this enhancer are confined to the Mad motif and flanking region. Our data suggest that this Mad motif may be functional in response to BMP signaling. ©2002 Elsevier Science (USA).
The Drosophila cell adhesion molecule Neuroglian regulates Lissencephaly-1 localisation in circulating immunosurveillance cells

Directory of Open Access Journals (Sweden)

Williams Michael J

2009-03-01

Full Text Available Abstract Background When the parasitoid wasp Leptopilina boulardi lays its eggs in Drosophila larvae phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. This requires these circulating immunosurveillance cells (haemocytes to change from a non-adhesive to an adhesive state enabling them to bind to the invader. Interestingly, attachment of leukocytes, platelets, and insect haemocytes requires the same adhesion complexes as epithelial and neuronal cells. Results Here evidence is presented showing that the Drosophila L1-type cell adhesion molecule Neuroglian (Nrg is required for haemocytes to encapsulate L. boulardi wasp eggs. The amino acid sequence FIGQY containing a conserved phosphorylated tyrosine is found in the intracellular domain of all L1-type cell adhesion molecules. This conserved tyrosine is phosphorylated at the cell periphery of plasmatocytes and lamellocytes prior to parasitisation, but dephosphorylated after immune activation. Intriguingly, another pool of Nrg located near the nucleus of plasmatocytes remains phosphorylated after parasitisation. In mammalian neuronal cells phosphorylated neurofascin, another L1-type cell adhesion molecule interacts with a nucleokinesis complex containing the microtubule binding protein lissencephaly-1 (Lis1 1. Interestingly in plasmatocytes from Nrg mutants the nucleokinesis regulating protein Lissencephaly-1 (Lis1 fails to localise properly around the nucleus and is instead found diffuse throughout the cytoplasm and at unidentified perinuclear structures. After attaching to the wasp egg control plasmatocytes extend filopodia laterally from their cell periphery; as well as extending lateral filopodia plasmatocytes from Nrg mutants also extend many filopodia from their apical surface. Conclusion The Drosophila cellular adhesion molecule Neuroglian is expressed in haemocytes and its activity is required for the encapsulation of L. boularli eggs. At
Primary structure and functional characterization of a Drosophila dopamine receptor with high homology to human D1/5 receptors.

Science.gov (United States)

Gotzes, F; Balfanz, S; Baumann, A

1994-01-01

Members of the superfamily of G-protein coupled receptors share significant similarities in sequence and transmembrane architecture. We have isolated a Drosophila homologue of the mammalian dopamine receptor family using a low stringency hybridization approach. The deduced amino acid sequence is approximately 70% homologous to the human D1/D5 receptors. When expressed in HEK 293 cells, the Drosophila receptor stimulates cAMP production in response to dopamine application. This effect was mimicked by SKF 38393, a specific D1 receptor agonist, but inhibited by dopaminergic antagonists such as butaclamol and flupentixol. In situ hybridization revealed that the Drosophila dopamine receptor is highly expressed in the somata of the optic lobes. This suggests that the receptor might be involved in the processing of visual information and/or visual learning in invertebrates.
Evidence for a Complex Class of Nonadenylated mRNA in Drosophila

Science.gov (United States)

Zimmerman, J. Lynn; Fouts, David L.; Manning, Jerry E.

1980-01-01

The amount, by mass, of poly(A+) mRNA present in the polyribosomes of third-instar larvae of Drosophila melanogaster, and the relative contribution of the poly(A+) mRNA to the sequence complexity of total polysomal RNA, has been determined. Selective removal of poly(A+) mRNA from total polysomal RNA by use of either oligo-dT-cellulose, or poly(U)-sepharose affinity chromatography, revealed that only 0.15% of the mass of the polysomal RNA was present as poly(A+) mRNA. The present study shows that this RNA hybridized at saturation with 3.3% of the single-copy DNA in the Drosophila genome. After correction for asymmetric transcription and reactability of the DNA, 7.4% of the single-copy DNA in the Drosophila genome is represented in larval poly(A+) mRNA. This corresponds to 6.73 x 106 nucleotides of mRNA coding sequences, or approximately 5,384 diverse RNA sequences of average size 1,250 nucleotides. However, total polysomal RNA hybridizes at saturation to 10.9% of the single-copy DNA sequences. After correcting this value for asymmetric transcription and tracer DNA reactability, 24% of the single-copy DNA in Drosophila is represented in total polysomal RNA. This corresponds to 2.18 x 107 nucleotides of RNA coding sequences or 17,440 diverse RNA molecules of size 1,250 nucleotides. This value is 3.2 times greater than that observed for poly(A+) mRNA, and indicates that ≃69% of the polysomal RNA sequence complexity is contributed by nonadenylated RNA. Furthermore, if the number of different structural genes represented in total polysomal RNA is ≃1.7 x 104, then the number of genes expressed in third-instar larvae exceeds the number of chromomeres in Drosophila by about a factor of three. This numerology indicates that the number of chromomeres observed in polytene chromosomes does not reflect the number of structural gene sequences in the Drosophila genome. PMID:6777246
[Architecture of the X chromosome, expression of LIM kinase 1, and recombination in the agnostic mutants of Drosophila: a model of human Williams syndrome].

Science.gov (United States)

Savvateeva-Popova, E V; Peresleni, A I; Sharagina, L M; Medvedeva, A V; Korochkina, S E; Grigor'eva, I V; Diuzhikova, N A; Popov, A V; Baricheva, E M; Karagodin, D; Heisenberg, M

2004-06-01

As the Human Genome and Drosophila Genome Projects were completed, it became clear that functions of human disease-associated genes may be elucidated by studying the phenotypic expression of mutations affecting their structural or functional homologs in Drosophila. Genomic diseases were identified as a new class of human disorders. Their cause is recombination, which takes place at gene-flanking duplicons to generate chromosome aberrations such as deletions, duplications, inversions, and translocations. The resulting imbalance of the dosage of developmentally important genes arises at a frequency of 10(-3) (higher than the mutation rate of individual genes) and leads to syndromes with multiple manifestations, including cognitive defects. Genomic DNA fragments were cloned from the Drosophila melanogaster agnostic locus, whose mutations impair learning ability and memory. As a result, the locus was exactly localized in X-chromosome region 11A containing the LIM kinase 1 (LIMK1) gene (CG1848), which is conserved among many species. Hemizygosity for the LIMK1 gene, which is caused by recombination at neighboring extended repeats, underlies cognitive disorders in human Williams syndrome. LIMK1 is a component of the integrin signaling cascade, which regulates the functions of the actin cytoskeleton, synaptogenesis, and morphogenesis in the developing brain. Immunofluorescence analysis revealed LIMK1 in all subdomains of the central complex and the visual system of Drosophila melanogaster. Like in the human genome, the D. melanogaster region is flanked by numerous repeats, which were detected by molecular genetic methods and analysis of ectopic chromosome pairing. The repeats determined a higher rate of spontaneous and induced recombination. including unequal crossing over, in the agnostic gene region. Hence, the agnostic locus was considered as the first D. melanogaster model suitable for studying the genetic defect associated with Williams syndrome in human.
Drosophila melanogaster gene expression changes after spaceflight.

Data.gov (United States)

National Aeronautics and Space Administration — Gene expression levels were determined in 3rd instar and adult Drosophila melanogaster reared during spaceflight to elucidate the genetic and molecular mechanisms...
The effects of temperature and diet on age grading and population age structure determination in Drosophila.

Science.gov (United States)

Aw, Wen C; Ballard, J William O

2013-10-01

The age structure of natural population is of interest in physiological, life history and ecological studies but it is often difficult to determine. One methodological problem is that samples may need to be invasively sampled preventing subsequent taxonomic curation. A second problem is that it can be very expensive to accurately determine the age structure of given population because large sample sizes are often necessary. In this study, we test the effects of temperature (17 °C, 23 °C and 26 °C) and diet (standard cornmeal and low calorie diet) on the accuracy of the non-invasive, inexpensive and high throughput near-infrared spectroscopy (NIRS) technique to determine the age of Drosophila flies. Composite and simplified calibration models were developed for each sex. Independent sets for each temperature and diet treatments with flies not involved in calibration model were then used to validate the accuracy of the calibration models. The composite NIRS calibration model was generated by including flies reared under all temperatures and diets. This approach permits rapid age measurement and age structure determination in large population of flies as less than or equal to 9 days, or more than 9 days old with 85-97% and 64-99% accuracy, respectively. The simplified calibration models were generated by including flies reared at 23 °C on standard diet. Low accuracy rates were observed when simplified calibration models were used to identify (a) Drosophila reared at 17 °C and 26 °C and (b) 23 °C with low calorie diet. These results strongly suggest that appropriate calibration models need to be developed in the laboratory before this technique can be reliably used in field. These calibration models should include the major environmental variables that change across space and time in the particular natural population to be studied. Copyright © 2013 Elsevier Ltd. All rights reserved.
PINK1 is required for timely cell-type specific mitochondrial clearance during Drosophila midgut metamorphosis.

Science.gov (United States)

Liu, Yan; Lin, Jingjing; Zhang, Minjie; Chen, Kai; Yang, Shengxi; Wang, Qun; Yang, Hongqin; Xie, Shusen; Zhou, Yongjian; Zhang, Xi; Chen, Fei; Yang, Yufeng

2016-11-15

Mitophagy is the selective degradation of mitochondria by autophagy, which is an important mitochondrial quality and quantity control process. During Drosophila metamorphosis, the degradation of midgut involves a large change in length and organization, which is mediated by autophagy. Here we noticed a cell-type specific mitochondrial clearance process that occurs in enterocytes (ECs), while most mitochondria remain in intestinal stem cells (ISCs) during metamorphosis. Although PINK1/PARKIN represent the canonical pathway for the elimination of impaired mitochondria in varied pathological conditions, their roles in developmental processes or normal physiological conditions have been less studied. To examine the potential contribution of PINK1 in developmental processes, we monitored the dynamic expression pattern of PINK1 in the midgut development by taking advantage of a newly CRISPR/Cas9 generated knock-in fly strain expressing PINK1-mCherry fusion protein that presumably recapitulates the endogenous expression pattern of PINK1. We disclosed a spatiotemporal correlation between the expression pattern of PINK1 and the mitochondrial clearance or persistence in ECs or ISCs respectively. By mosaic genetic analysis, we then demonstrated that PINK1 and PARKIN function epistatically to mediate the specific timely removal of mitochondria, and are involved in global autophagy in ECs during Drosophila midgut metamorphosis, with kinase-dead PINK1 exerting dominant negative effects. Taken together, our studies concluded that the PINK1/PARKIN is crucial for timely cell-type specific mitophagy under physiological conditions and demonstrated again that Drosophila midgut metamorphosis might serve as an elegant in vivo model to study autophagy. Copyright Â© 2016 Elsevier Inc. All rights reserved.
Gut-associated microbes of Drosophila melanogaster

Science.gov (United States)

Broderick, Nichole; Lemaitre, Bruno

2012-01-01

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

Science.gov (United States)

Fear, Justin M; Arbeitman, Michelle N; Salomon, Matthew P; Dalton, Justin E; Tower, John; Nuzhdin, Sergey V; McIntyre, Lauren M

2015-09-04

The Drosophila sex determination hierarchy is a classic example of a transcriptional regulatory hierarchy, with sex-specific isoforms regulating morphology and behavior. We use a structural equation modeling approach, leveraging natural genetic variation from two studies on Drosophila female head tissues--DSPR collection (596 F1-hybrids from crosses between DSPR sub-populations) and CEGS population (75 F1-hybrids from crosses between DGRP/Winters lines to a reference strain w1118)--to expand understanding of the sex hierarchy gene regulatory network (GRN). This approach is completely generalizable to any natural population, including humans. We expanded the sex hierarchy GRN adding novel links among genes, including a link from fruitless (fru) to Sex-lethal (Sxl) identified in both populations. This link is further supported by the presence of fru binding sites in the Sxl locus. 754 candidate genes were added to the pathway, including the splicing factors male-specific lethal 2 and Rm62 as downstream targets of Sxl which are well-supported links in males. Independent studies of doublesex and transformer mutants support many additions, including evidence for a link between the sex hierarchy and metabolism, via Insulin-like receptor. The genes added in the CEGS population were enriched for genes with sex-biased splicing and components of the spliceosome. A common goal of molecular biologists is to expand understanding about regulatory interactions among genes. Using natural alleles we can not only identify novel relationships, but using supervised approaches can order genes into a regulatory hierarchy. Combining these results with independent large effect mutation studies, allows clear candidates for detailed molecular follow-up to emerge.
A Polymorphism in the Processing Body Component Ge-1 Controls Resistance to a Naturally Occurring Rhabdovirus in Drosophila.

Directory of Open Access Journals (Sweden)

Chuan Cao

2016-01-01

Full Text Available Hosts encounter an ever-changing array of pathogens, so there is continual selection for novel ways to resist infection. A powerful way to understand how hosts evolve resistance is to identify the genes that cause variation in susceptibility to infection. Using high-resolution genetic mapping we have identified a naturally occurring polymorphism in a gene called Ge-1 that makes Drosophila melanogaster highly resistant to its natural pathogen Drosophila melanogaster sigma virus (DMelSV. By modifying the sequence of the gene in transgenic flies, we identified a 26 amino acid deletion in the serine-rich linker region of Ge-1 that is causing the resistance. Knocking down the expression of the susceptible allele leads to a decrease in viral titre in infected flies, indicating that Ge-1 is an existing restriction factor whose antiviral effects have been increased by the deletion. Ge-1 plays a central role in RNA degradation and the formation of processing bodies (P bodies. A key effector in antiviral immunity, the RNAi induced silencing complex (RISC, localises to P bodies, but we found that Ge-1-based resistance is not dependent on the small interfering RNA (siRNA pathway. However, we found that Decapping protein 1 (DCP1 protects flies against sigma virus. This protein interacts with Ge-1 and commits mRNA for degradation by removing the 5' cap, suggesting that resistance may rely on this RNA degradation pathway. The serine-rich linker domain of Ge-1 has experienced strong selection during the evolution of Drosophila, suggesting that this gene may be under long-term selection by viruses. These findings demonstrate that studying naturally occurring polymorphisms that increase resistance to infections enables us to identify novel forms of antiviral defence, and support a pattern of major effect polymorphisms controlling resistance to viruses in Drosophila.
An Org-1-Tup transcriptional cascade reveals different types of alary muscles connecting internal organs in Drosophila.

Science.gov (United States)

Boukhatmi, Hadi; Schaub, Christoph; Bataillé, Laetitia; Reim, Ingolf; Frendo, Jean-Louis; Frasch, Manfred; Vincent, Alain

2014-10-01

The T-box transcription factor Tbx1 and the LIM-homeodomain transcription factor Islet1 are key components in regulatory circuits that generate myogenic and cardiogenic lineage diversity in chordates. We show here that Org-1 and Tup, the Drosophila orthologs of Tbx1 and Islet1, are co-expressed and required for formation of the heart-associated alary muscles (AMs) in the abdomen. The same holds true for lineage-related muscles in the thorax that have not been described previously, which we name thoracic alary-related muscles (TARMs). Lineage analyses identified the progenitor cell for each AM and TARM. Three-dimensional high-resolution analyses indicate that AMs and TARMs connect the exoskeleton to the aorta/heart and to different regions of the midgut, respectively, and surround-specific tracheal branches, pointing to an architectural role in the internal anatomy of the larva. Org-1 controls tup expression in the AM/TARM lineage by direct binding to two regulatory sites within an AM/TARM-specific cis-regulatory module, tupAME. The contributions of Org-1 and Tup to the specification of Drosophila AMs and TARMs provide new insights into the transcriptional control of Drosophila larval muscle diversification and highlight new parallels with gene regulatory networks involved in the specification of cardiopharyngeal mesodermal derivatives in chordates. © 2014. Published by The Company of Biologists Ltd.
Female Remating, Sperm Competition and Sexual Selection in Drosophila

OpenAIRE

Singh, Dr. Shree Ram; Singh, Dr. B N; Hoenigsberg, Dr. H F

2002-01-01

Female remating is the fundamental to evolutionary biology as it determines the pattern of sexual selection and sexual conflict. Remating in females is an important component of Drosophila mating systems because it is associated with pattern of sperm usage and sexual selection. Remating is common in females of many species of Drosophila in both natural and laboratory populations. It is reported in many insect species and vertebrates also. Female remating is prerequisite for the ...
Control of male sexual behavior in Drosophila by the sex determination pathway

NARCIS (Netherlands)

Billeter, Jean-Christophe; Rideout, Elizabeth J; Dornan, Anthony J; Goodwin, Stephen F

2006-01-01

Understanding how genes influence behavior, including sexuality, is one of biology's greatest challenges. Much of the recent progress in understanding how single genes can influence behavior has come from the study of innate behaviors in the fruit fly Drosophila melanogaster. In particular, the
A biological timer in the fat body comprising Blimp-1, βFtz-f1 and Shade regulates pupation timing in Drosophila melanogaster.

Science.gov (United States)

Akagi, Kazutaka; Sarhan, Moustafa; Sultan, Abdel-Rahman S; Nishida, Haruka; Koie, Azusa; Nakayama, Takumi; Ueda, Hitoshi

2016-07-01

During the development of multicellular organisms, many events occur with precise timing. In Drosophila melanogaster, pupation occurs about 12 h after puparium formation and its timing is believed to be determined by the release of a steroid hormone, ecdysone (E), from the prothoracic gland. Here, we demonstrate that the ecdysone-20-monooxygenase Shade determines pupation timing by converting E to 20-hydroxyecdysone (20E) in the fat body, which is the organ that senses nutritional status. The timing of shade expression is determined by its transcriptional activator βFtz-f1. The βftz-f1 gene is activated after a decline in the expression of its transcriptional repressor Blimp-1, which is temporally expressed around puparium formation in response to a high titer of 20E. The expression level and stability of Blimp-1 is critical for the precise timing of pupation. Thus, we propose that Blimp-1 molecules function like sand in an hourglass in this precise developmental timer system. Furthermore, our data suggest that a biological advantage results from both the use of a transcriptional repressor for time determination and the association of developmental timing with nutritional status of the organism. © 2016. Published by The Company of Biologists Ltd.
La violencia contra niños y niñas: un problema global de abordaje local, mediante la IAP

Directory of Open Access Journals (Sweden)

Alejandro Acosta-Ayerbe

2013-03-01

Full Text Available En el presente artículo nos ocupamos de las dimensiones y gravedad de la presencia actual de la violencia1 contra la niñez, reflejada en diferentes estudios, informes y recomendaciones de gobiernos y organismos nacionales e internacionales, y de la necesidad de recurrir a opciones de trabajo como la Investigación Acción Participativa, IAP, que permitan abordar la complejidad de los sujetos implicados, por la particularidad que traza la convergencia de factores sociales, culturales, económicos, familiares, personales y jurídicos, en cada contexto.
Modeling Human Cancers in Drosophila.

Science.gov (United States)

Sonoshita, M; Cagan, R L

2017-01-01

Cancer is a complex disease that affects multiple organs. Whole-body animal models provide important insights into oncology that can lead to clinical impact. Here, we review novel concepts that Drosophila studies have established for cancer biology, drug discovery, and patient therapy. Genetic studies using Drosophila have explored the roles of oncogenes and tumor-suppressor genes that when dysregulated promote cancer formation, making Drosophila a useful model to study multiple aspects of transformation. Not limited to mechanism analyses, Drosophila has recently been showing its value in facilitating drug development. Flies offer rapid, efficient platforms by which novel classes of drugs can be identified as candidate anticancer leads. Further, we discuss the use of Drosophila as a platform to develop therapies for individual patients by modeling the tumor's genetic complexity. Drosophila provides both a classical and a novel tool to identify new therapeutics, complementing other more traditional cancer tools. © 2017 Elsevier Inc. All rights reserved.
Toxic and biochemical effects of divalent metal ions in Drosophila: correlation to effects in mice and to chemical softness parameters

Energy Technology Data Exchange (ETDEWEB)

Jacobson, K B; Turner, J E; Christie, N T; Owenby, R K

1983-01-01

The mechanism of toxicity of 11 divalent cations was evaluated by determining the effects of dietary administration to Drosophila melanogaster and measurement of the frequency of lethality at 4 days, alterations in the developmental patterns of proteins, and changes in specific transfer RNAs. The relative effectiveness of divalent cations to kill Drosophila is significantly correlated to the relative values of the coordinate bond energy of the metal ions. The resistance of Drosophila to cadmium toxicity appears to be genetically determined since different inbred strains vary markedly. Also, the resistance is maximal in the young adult. Two different genetic strains seem to respond to different cations (Cd/sup 2 +/, Hg/sup 2 +/, Cu/sup 2 +/, Co/sup 2 +/, Ba/sup 2 +/, and Sr/sup 2 +/) in a similar manner. Basic mechanisms of toxicity may be studied in Drosophila as well as mice since the chemical properties of the metals reflect their toxic effects on the former as closely as the latter. 25 references, 5 figures, 1 table.
Semi-automated quantitative Drosophila wings measurements.

Science.gov (United States)

Loh, Sheng Yang Michael; Ogawa, Yoshitaka; Kawana, Sara; Tamura, Koichiro; Lee, Hwee Kuan

2017-06-28

Drosophila melanogaster is an important organism used in many fields of biological research such as genetics and developmental biology. Drosophila wings have been widely used to study the genetics of development, morphometrics and evolution. Therefore there is much interest in quantifying wing structures of Drosophila. Advancement in technology has increased the ease in which images of Drosophila can be acquired. However such studies have been limited by the slow and tedious process of acquiring phenotypic data. We have developed a system that automatically detects and measures key points and vein segments on a Drosophila wing. Key points are detected by performing image transformations and template matching on Drosophila wing images while vein segments are detected using an Active Contour algorithm. The accuracy of our key point detection was compared against key point annotations of users. We also performed key point detection using different training data sets of Drosophila wing images. We compared our software with an existing automated image analysis system for Drosophila wings and showed that our system performs better than the state of the art. Vein segments were manually measured and compared against the measurements obtained from our system. Our system was able to detect specific key points and vein segments from Drosophila wing images with high accuracy.

A Herpes Simplex Virus Type 1 Mutant Expressing a Baculovirus Inhibitor of Apoptosis Gene in Place of Latency-Associated Transcript Has a Wild-Type Reactivation Phenotype in the Mouse

Science.gov (United States)

Jin, Ling; Perng, Guey-Chuen; Mott, Kevin R.; Osorio, Nelson; Naito, Julia; Brick, David J.; Carpenter, Dale; Jones, Clinton; Wechsler, Steven L.

2005-01-01

The latency-associated transcript (LAT) is essential for the wild-type herpes simplex virus type 1 (HSV-1) high-reactivation phenotype since LAT− mutants have a low-reactivation phenotype. We previously reported that LAT can decrease apoptosis and proposed that this activity is involved in LAT's ability to enhance the HSV-1 reactivation phenotype. The first 20% of the primary 8.3-kb LAT transcript is sufficient for enhancing the reactivation phenotype and for decreasing apoptosis, supporting this proposal. For this study, we constructed an HSV-1 LAT− mutant that expresses the baculovirus antiapoptosis gene product cpIAP under control of the LAT promoter and in place of the LAT region mentioned above. Mice were ocularly infected with this mutant, designated dLAT-cpIAP, and the reactivation phenotype was determined using the trigeminal ganglion explant model. dLAT-cpIAP had a reactivation phenotype similar to that of wild-type virus and significantly higher than that of (i) the LAT− mutant dLAT2903; (ii) dLAT1.5, a control virus containing the same LAT deletion as dLAT-cpIAP, but with no insertion of foreign DNA, thereby controlling for potential readthrough transcription past the cpIAP insert; and (iii) dLAT-EGFP, a control virus identical to dLAT-cpIAP except that it contained the enhanced green fluorescent protein open reading frame (ORF) in place of the cpIAP ORF, thereby controlling for expression of a random foreign gene instead of the cpIAP gene. These results show that an antiapoptosis gene with no sequence similarity to LAT can efficiently substitute for the LAT function involved in enhancing the in vitro-induced HSV-1 reactivation phenotype in the mouse. PMID:16160155
Neuronal Cbl Controls Biosynthesis of Insulin-Like Peptides in Drosophila melanogaster

OpenAIRE

Yu, Yue; Sun, Ying; He, Shengqi; Yan, Cheng; Rui, Liangyou; Li, Wenjun; Liu, Yong

2012-01-01

The Cbl family proteins function as both E3 ubiquitin ligases and adaptor proteins to regulate various cellular signaling events, including the insulin/insulin-like growth factor 1 (IGF1) and epidermal growth factor (EGF) pathways. These pathways play essential roles in growth, development, metabolism, and survival. Here we show that in Drosophila melanogaster, Drosophila Cbl (dCbl) regulates longevity and carbohydrate metabolism through downregulating the production of Drosophila insulin-lik...
Drosophila melanogaster as a Versatile Model Organism in Food and Nutrition Research.

Science.gov (United States)

Staats, Stefanie; Lüersen, Kai; Wagner, Anika E; Rimbach, Gerald

2018-04-18

Drosophila melanogaster has been widely used in the biological sciences as a model organism. Drosophila has a relatively short life span of 60-80 days, which makes it attractive for life span studies. Moreover, approximately 60% of the fruit fly genes are orthologs to mammals. Thus, metabolic and signal transduction pathways are highly conserved. Maintenance and reproduction of Drosophila do not require sophisticated equipment and are rather cheap. Furthermore, there are fewer ethical issues involved in experimental Drosophila research compared with studies in laboratory rodents, such as rats and mice. Drosophila is increasingly recognized as a model organism in food and nutrition research. Drosophila is often fed complex solid diets based on yeast, corn, and agar. There are also so-called holidic diets available that are defined in terms of their amino acid, fatty acid, carbohydrate, vitamin, mineral, and trace element compositions. Feed intake, body composition, locomotor activity, intestinal barrier function, microbiota, cognition, fertility, aging, and life span can be systematically determined in Drosophila in response to dietary factors. Furthermore, diet-induced pathophysiological mechanisms including inflammation and stress responses may be evaluated in the fly under defined experimental conditions. Here, we critically evaluate Drosophila melanogaster as a versatile model organism in experimental food and nutrition research, review the corresponding data in the literature, and make suggestions for future directions of research.
Evolutionary changes in gene expression, coding sequence and copy-number at the Cyp6g1 locus contribute to resistance to multiple insecticides in Drosophila.

Directory of Open Access Journals (Sweden)

Thomas W R Harrop

Full Text Available Widespread use of insecticides has led to insecticide resistance in many populations of insects. In some populations, resistance has evolved to multiple pesticides. In Drosophila melanogaster, resistance to multiple classes of insecticide is due to the overexpression of a single cytochrome P450 gene, Cyp6g1. Overexpression of Cyp6g1 appears to have evolved in parallel in Drosophila simulans, a sibling species of D. melanogaster, where it is also associated with insecticide resistance. However, it is not known whether the ability of the CYP6G1 enzyme to provide resistance to multiple insecticides evolved recently in D. melanogaster or if this function is present in all Drosophila species. Here we show that duplication of the Cyp6g1 gene occurred at least four times during the evolution of different Drosophila species, and the ability of CYP6G1 to confer resistance to multiple insecticides exists in D. melanogaster and D. simulans but not in Drosophila willistoni or Drosophila virilis. In D. virilis, which has multiple copies of Cyp6g1, one copy confers resistance to DDT and another to nitenpyram, suggesting that the divergence of protein sequence between copies subsequent to the duplication affected the activity of the enzyme. All orthologs tested conferred resistance to one or more insecticides, suggesting that CYP6G1 had the capacity to provide resistance to anthropogenic chemicals before they existed. Finally, we show that expression of Cyp6g1 in the Malpighian tubules, which contributes to DDT resistance in D. melanogaster, is specific to the D. melanogaster-D. simulans lineage. Our results suggest that a combination of gene duplication, regulatory changes and protein coding changes has taken place at the Cyp6g1 locus during evolution and this locus may play a role in providing resistance to different environmental toxins in different Drosophila species.
Drosophila's contribution to stem cell research [v1; ref status: indexed, http://f1000r.es/5h7

Directory of Open Access Journals (Sweden)

Gyanesh Singh

2015-06-01

Full Text Available The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. A recent development in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub. Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila.
Effect of the gene transformer of Anastrepha on the somatic sexual development of Drosophila.

Science.gov (United States)

Ruiz, María-Fernanda; Sánchez, Lucas

2010-01-01

The gene transformer (tra) is the key regulatory memory device for sex determination in tephritid insects. The present manuscript addressed the question about the functional conservation of the tephritid Anastrepha Transformer protein to direct somatic sexual development in Drosophila (Drosophilidae). The transformer cDNA of Anastrepha encoding the putative full-length Tra protein was cloned in pUAST and introduced into Drosophila melanogaster. To express this protein, the GAL4-UAS system was used. The Anastrepha Tra protein induced the female-specific splicing of both dsx and fru pre-mRNAs in Drosophila XY male flies, so that these became transformed into females, though this transformation was incomplete (the sexually dimorphic foreleg basitarsus and the external terminalia were monitored). It was found that the degree of female transformation directly depended on the dose of Anastrepha tra and Drosophila transformer-2 (tra-2) genes, and that the Anastrepha Tra-Drosophila Tra2 complex is not as efficient as the Drosophila Tra-Tra2 complex at inducing the female-specific splicing of Drosophila dsx pre-mRNA. This can explain why the Anastrepha Tra protein cannot fully substitute for the endogenous Drosophila Tra protein.
Impact of Sampling and Cellular Separation on Amino Acid Determinations in Drosophila Hemolymph.

Science.gov (United States)

Cabay, Marissa R; Harris, Jasmine C; Shippy, Scott A

2018-04-03

The fruit fly is a frequently used model system with a high degree of human disease-related genetic homology. The quantitative chemical analysis of fruit fly tissues and hemolymph uniquely brings chemical signaling and compositional information to fly experimentation. The work here explores the impact of measured chemical content of hemolymph with three aspects of sample collection and preparation. Cellular content of hemolymph was quantitated and removed to determine hemolymph composition changes for seven primary amine analytes. Hemolymph sampling methods were adapted to determine differences in primary amine composition of hemolymph collected from the head, antenna, and abdomen. Also, three types of anesthesia were employed with hemolymph collection to quantitate effects on measured amino acid content. Cell content was found to be 45.4 ± 22.1 cells/nL of hemolymph collected from both adult and larvae flies. Cell-concentrated fractions of adult, but not larvae, hemolymph were found to have higher and more variable amine content. There were amino acid content differences found between all three areas indicating a robust method to characterize chemical markers from specific regions of a fly, and these appear related to physiological activity. Methods of anesthesia have an impact on hemolymph amino acid composition related to overall physiological impact to fly including higher amino acid content variability and oxygen deprivation effects. Together, these analyses identify potential complications with Drosophila hemolymph analysis and opportunities for future studies to relate hemolymph content with model physiological activity.
Temperature-dependent sex-reversal by a transformer-2 gene-edited mutation in the spotted wing drosophila, Drosophila suzukii

Science.gov (United States)

Female to male sex reversal was achieved in an emerging agricultural insect pest, Drosophila suzukii, by creating a temperature-sensitive point mutation in the sex-determination gene, transformer-2 (tra-2) using CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/ CRISPR-associated) hom...
Dscam1-mediated self-avoidance counters netrin-dependent targeting of dendrites in Drosophila.

Science.gov (United States)

Matthews, Benjamin J; Grueber, Wesley B

2011-09-13

Dendrites and axons show precise targeting and spacing patterns for proper reception and transmission of information in the nervous system. Self-avoidance promotes complete territory coverage and nonoverlapping spacing between processes from the same cell [1, 2]. Neurons that lack Drosophila Down syndrome cell adhesion molecule 1 (Dscam1) show aberrant overlap, fasciculation, and accumulation of dendrites and axons, demonstrating a role in self-recognition and repulsion leading to self-avoidance [3-11]. Fasciculation and accumulation of processes suggested that Dscam1 might promote process spacing by counterbalancing developmental signals that otherwise promote self-association [9, 12]. Here we show that Dscam1 functions to counter Drosophila sensory neuron dendritic targeting signals provided by secreted Netrin-B and Frazzled, a netrin receptor. Loss of Dscam1 function resulted in aberrant dendrite accumulation at a Netrin-B-expressing target, whereas concomitant loss of Frazzled prevented accumulation and caused severe deficits in dendritic territory coverage. Netrin misexpression was sufficient to induce ectopic dendritic targeting in a Frazzled-dependent manner, whereas Dscam1 was required to prevent ectopic accumulation, consistent with separable roles for these receptors. Our results suggest that Dscam1-mediated self-avoidance counters extrinsic signals that are required for normal dendritic patterning, but whose action would otherwise favor neurite accumulation. Counterbalancing roles for Dscam1 may be deployed in diverse contexts during neural circuit formation. Copyright © 2011 Elsevier Ltd. All rights reserved.
Myoblast fusion in Drosophila

Energy Technology Data Exchange (ETDEWEB)

Haralalka, Shruti [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Abmayr, Susan M., E-mail: sma@stowers.org [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, MO 66160 (United States)

2010-11-01

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

International Nuclear Information System (INIS)

Haralalka, Shruti; Abmayr, Susan M.

2010-01-01

The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.
The cytoskeleton of Drosophila-derived Schneider line-1 and Kc23 cells undergoes significant changes during long-term culture

Science.gov (United States)

Schatten, H.; Hedrick, J.; Chakrabarti, A.

1998-01-01

Insect cell cultures derived from Drosophila melanogaster are increasingly being used as an alternative system to mammalian cell cultures, as they are amenable to genetic manipulation. Although Drosophila cells are an excellent tool for the study of genes and expression of proteins, culture conditions have to be considered in the interpretation of biochemical results. Our studies indicate that significant differences occur in cytoskeletal structure during the long-term culture of the Drosophila-derived cell lines Schneider Line-1 (S1) and Kc23. Scanning, transmission-electron, and immunofluorescence microscopy studies reveal that microfilaments, microtubules, and centrosomes become increasingly different during the culture of these cells from 24 h to 7-14 days. Significant cytoskeletal changes are observed at the cell surface where actin polymerizes into microfilaments, during the elongation of long microvilli. Additionally, long protrusions develop from the cell surface; these protrusions are microtubule-based and establish contact with neighboring cells. In contrast, the microtubule network in the interior of the cells becomes disrupted after four days of culture, resulting in altered transport of mitochondria. Microtubules and centrosomes are also affected in a small percent of cells during cell division, indicating an instability of centrosomes. Thus, the cytoskeletal network of microfilaments, microtubules, and centrosomes is affected in Drosophila cells during long-term culture. This implies that gene regulation and post-translational modifications are probably different under different culture conditions.
DISCO interacting protein 2 determines direction of axon projection under the regulation of c-Jun N-terminal kinase in the Drosophila mushroom body

International Nuclear Information System (INIS)

Nitta, Yohei; Sugie, Atsushi

2017-01-01

Precisely controlled axon guidance for complex neuronal wiring is essential for appropriate neuronal function. c-Jun N-terminal kinase (JNK) was found to play a role in axon guidance recently as well as in cell proliferation, protection and apoptosis. In spite of many genetic and molecular studies on these biological processes regulated by JNK, how JNK regulates axon guidance accurately has not been fully explained thus far. To address this question, we use the Drosophila mushroom body (MB) as a model since the α/β axons project in two distinct directions. Here we show that DISCO interacting protein 2 (DIP2) is required for the accurate direction of axonal guidance. DIP2 expression is under the regulation of Basket (Bsk), the Drosophila homologue of JNK. We additionally found that the Bsk/DIP2 pathway is independent from the AP-1 transcriptional factor complex pathway, which is directly activated by Bsk. In conclusion, our findings revealed DIP2 as a novel effector downstream of Bsk modulating the direction of axon projection. - Highlights: • DIP2 is required for accurate direction of axon guidance in Drosophila mushroom body. • DIP2 is a downstream of JNK in the axon guidance of Drosophila mushroom body neuron. • JNK/DIP2 pathway is independent from JNK/AP-1 transcriptional factor complex pathway.
Drosophila homologues of adenomatous polyposis coli (APC) and the formin diaphanous collaborate by a conserved mechanism to stimulate actin filament assembly.

Science.gov (United States)

Jaiswal, Richa; Stepanik, Vince; Rankova, Aneliya; Molinar, Olivia; Goode, Bruce L; McCartney, Brooke M

2013-05-10

Vertebrate APC collaborates with Dia through its Basic domain to assemble actin filaments. Despite limited sequence homology between the vertebrate and Drosophila APC Basic domains, Drosophila APC1 collaborates with Dia to stimulate actin assembly in vitro. The mechanism of actin assembly is highly conserved over evolution. APC-Dia collaborations may be crucial in a wide range of animal cells. Adenomatous polyposis coli (APC) is a large multidomain protein that regulates the cytoskeleton. Recently, it was shown that vertebrate APC through its Basic domain directly collaborates with the formin mDia1 to stimulate actin filament assembly in the presence of nucleation barriers. However, it has been unclear whether these activities extend to homologues of APC and Dia in other organisms. Drosophila APC and Dia are each required to promote actin furrow formation in the syncytial embryo, suggesting a potential collaboration in actin assembly, but low sequence homology between the Basic domains of Drosophila and vertebrate APC has left their functional and mechanistic parallels uncertain. To address this question, we purified Drosophila APC1 and Dia and determined their individual and combined effects on actin assembly using both bulk fluorescence assays and total internal reflection fluorescence microscopy. Our data show that APC1, similar to its vertebrate homologue, bound to actin monomers and nucleated and bundled filaments. Further, Drosophila Dia nucleated actin assembly and protected growing filament barbed ends from capping protein. Drosophila APC1 and Dia directly interacted and collaborated to promote actin assembly in the combined presence of profilin and capping protein. Thus, despite limited sequence homology, Drosophila and vertebrate APCs exhibit highly related activities and mechanisms and directly collaborate with formins. These results suggest that APC-Dia interactions in actin assembly are conserved and may underlie important in vivo functions in a broad
What use is an infertile sperm? A comparative study of sperm-heteromorphic Drosophila

DEFF Research Database (Denmark)

Holman, Luke; Freckleton, Robert P; Snook, Rhonda R

2007-01-01

Sperm size and number are important determinants of male reproductive success. The genus Drosophila exhibits a remarkable diversity of sperm production strategies, including the production of multiple sperm morphs by individual males, a phenomenon called sperm heteromorphism. Sperm-heteromorphic ......Sperm size and number are important determinants of male reproductive success. The genus Drosophila exhibits a remarkable diversity of sperm production strategies, including the production of multiple sperm morphs by individual males, a phenomenon called sperm heteromorphism. Sperm......-heteromorphic Drosophila species in the obscura group produce large numbers of infertile "parasperm" in addition to fertile eusperm. Parasperm have been hypothesized to perform a number of roles in place of fertilization, predominantly focused on their potential function in postcopulatory sexual selection. However...
Ras1 interacts with multiple new signaling and cytoskeletal loci in Drosophila eggshell patterning and morphogenesis.

Science.gov (United States)

Schnorr, J D; Holdcraft, R; Chevalier, B; Berg, C A

2001-10-01

Little is known about the genes that interact with Ras signaling pathways to regulate morphogenesis. The synthesis of dorsal eggshell structures in Drosophila melanogaster requires multiple rounds of Ras signaling followed by dramatic epithelial sheet movements. We took advantage of this process to identify genes that link patterning and morphogenesis; we screened lethal mutations on the second chromosome for those that could enhance a weak Ras1 eggshell phenotype. Of 1618 lethal P-element mutations tested, 13 showed significant enhancement, resulting in forked and fused dorsal appendages. Our genetic and molecular analyses together with information from the Berkeley Drosophila Genome Project reveal that 11 of these lines carry mutations in previously characterized genes. Three mutations disrupt the known Ras1 cell signaling components Star, Egfr, and Blistered, while one mutation disrupts Sec61beta, implicated in ligand secretion. Seven lines represent cell signaling and cytoskeletal components that are new to the Ras1 pathway; these are Chickadee (Profilin), Tec29, Dreadlocks, POSH, Peanut, Smt3, and MESK2, a suppressor of dominant-negative Ksr. A twelfth insertion disrupts two genes, Nrk, a "neurospecific" receptor tyrosine kinase, and Tpp, which encodes a neuropeptidase. These results suggest that Ras1 signaling during oogenesis involves novel components that may be intimately associated with additional signaling processes and with the reorganization of the cytoskeleton. To determine whether these Ras1 Enhancers function upstream or downstream of the Egf receptor, four mutations were tested for their ability to suppress an activated Egfr construct (lambdatop) expressed in oogenesis exclusively in the follicle cells. Mutations in Star and l(2)43Bb had no significant effect upon the lambdatop eggshell defect whereas smt3 and dock alleles significantly suppressed the lambdatop phenotype.
The Drosophila melanogaster host model

Science.gov (United States)

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

2012-01-01

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

Directory of Open Access Journals (Sweden)

Christina O. Igboin

2012-02-01

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

Science.gov (United States)

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

2012-01-01

The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen-host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial-host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis-host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.
A Baculovirus immediate-early gene, ie1, promoter drives efficient expression of a transgene in both Drosophila melanogaster and Bombyx mori.

Directory of Open Access Journals (Sweden)

Mika Masumoto

Full Text Available Many promoters have been used to drive expression of heterologous transgenes in insects. One major obstacle in the study of non-model insects is the dearth of useful promoters for analysis of gene function. Here, we investigated whether the promoter of the immediate-early gene, ie1, from the Bombyx mori nucleopolyhedrovirus (BmNPV could be used to drive efficient transgene expression in a wide variety of insects. We used a piggyBac-based vector with a 3xP3-DsRed transformation marker to generate a reporter construct; this construct was used to determine the expression patterns driven by the BmNPV ie1 promoter; we performed a detailed investigation of the promoter in transgene expression pattern in Drosophila melanogaster and in B. mori. Drosophila and Bombyx belong to different insect orders (Diptera and Lepidoptera, respectively; however, and to our surprise, ie1 promoter-driven expression was evident in several tissues (e.g., prothoracic gland, midgut, and tracheole in both insects. Furthermore, in both species, the ie1 promoter drove expression of the reporter gene from a relatively early embryonic stage, and strong ubiquitous ie1 promoter-driven expression continued throughout the larval, pupal, and adult stages by surface observation. Therefore, we suggest that the ie1 promoter can be used as an efficient expression driver in a diverse range of insect species.

Study of radioadaptive response in Drosophila melanogaster at different oogenesis stages

International Nuclear Information System (INIS)

Glushkova, I.V.; Aksyutik, T.V.

2005-01-01

We study radioadaptive response in the Canton-S strain of Drosophila melanogaster at different oogenesis stages using the test of dominant lethal mutations (DLM). AR was not revealed at the stages of 14-7 and 7--1 oocytes in the studied Drosophila stock. It is likely to be associated with a genetic constitution of the Drosophila strain under study. (authors)
Early events in speciation: Polymorphism for hybrid male sterility in Drosophila

OpenAIRE

Reed, Laura K.; Markow, Therese A.

2004-01-01

Capturing the process of speciation early enough to determine the initial genetic causes of reproductive isolation remains a major challenge in evolutionary biology. We have found, to our knowledge, the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. Specifically, we show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, Drosophila arizonae, is controlled by factors p...
Oral antibodies to human intestinal alkaline phosphatase reduce dietary phytate phosphate bioavailability in the presence of dietary 1α-hydroxycholecalciferol.

Science.gov (United States)

Bobeck, Elizabeth A; Hellestad, Erica M; Helvig, Christian F; Petkovich, P Martin; Cook, Mark E

2016-03-01

While it is well established that active vitamin D treatment increases dietary phytate phosphate utilization, the mechanism by which intestinal alkaline phosphatase (IAP) participates in phytate phosphate use is less clear. The ability of human IAP (hIAP) oral antibodies to prevent dietary phytate phosphate utilization in the presence of 1α-hydroxycholecalciferol (1α-(OH) D3) in a chick model was investigated. hIAP specific chicken immunoglobulin Y (IgY) antibodies were generated by inoculating laying hens with 17 synthetic peptides derived from the human IAP amino acid sequence and harvesting egg yolk. Western blot analysis showed all antibodies recognized hIAP and 6 of the 8 antibodies selected showed modest inhibition of hIAP activity in vitro (6 to 33% inhibition). In chicks where dietary phosphate was primarily in the form of phytate, 4 selected hIAP antibodies inhibited 1α-(OH) D3-induced increases in blood phosphate, one of which, generated against selected peptide (MFPMGTPD), was as effective as sevelamer hydrochloride in preventing the 1α-(OH) D3-induced increase in blood phosphate, but ineffective in preventing an increase in body weight gain and bone ash induced by 1α-(OH) D3. These studies demonstrated that orally-delivered antibodies to IAP limit dietary phytate-phosphate utilization in chicks treated with 1α-(OH) D3, and implicate IAP as an important host enzyme in increasing phytate phosphate bioavailability in 1α-(OH) D3 fed chicks. © 2015 Poultry Science Association Inc.
Negative regulation of MAP kinase signaling in Drosophila by Ptp61F/PTP1B.

Science.gov (United States)

Tchankouo-Nguetcheu, Stéphane; Udinotti, Mario; Durand, Marjorie; Meng, Tzu-Ching; Taouis, Mohammed; Rabinow, Leonard

2014-10-01

PTP1B is an important negative regulator of insulin and other signaling pathways in mammals. However, the role of PTP1B in the regulation of RAS-MAPK signaling remains open to deliberation, due to conflicting evidence from different experimental systems. The Drosophila orthologue of mammalian PTP1B, PTP61F, has until recently remained largely uncharacterized. To establish the potential role of PTP61F in the regulation of signaling pathways in Drosophila and particularly to help resolve its fundamental function in RAS-MAPK signaling, we generated a new allele of Ptp61F as well as employed both RNA interference and overexpression alleles. Our results validate recent data showing that the activity of insulin and Abl kinase signaling is increased in Ptp61F mutants and RNA interference lines. Importantly, we establish negative regulation of the RAS/MAPK pathway by Ptp61F activity in whole animals. Of particular interest, our results document the modulation of hyperactive MAP kinase activity by Ptp61F alleles, showing that the phosphatase intervenes to directly or indirectly regulate MAP kinase itself.
[Studies of the repair of radiation-induced genetic damage in Drosophila]. Annual progress report, February 1, 1993 - November 1, 1994

International Nuclear Information System (INIS)

Hawley, R.S.

1998-01-01

This research focuses on two repair deficient mutations in Drosophila melanogaster, namely mei-9, mei-41. In addition, the authors propose to extend this study to include the mus-312 mutation. They expect these studies to provide substantial insights into both the molecular mechanisms of DNA repair in Drosophila and the role these genes play in normal biological processes
Hermann Muller and Mutations in Drosophila

Science.gov (United States)

dropdown arrow Site Map A-Z Index Menu Synopsis Hermann Muller and Mutations in Drosophila Resources with University of Texas. In Austin his experiments on fruit flies (Drosophila) first showed that exposure to September to spend a year at the only Drosophila laboratory in Europe which was doing parallel work
Anti-Aging Effect of Riboflavin Via Endogenous Antioxidant in Fruit fly Drosophila Melanogaster.

Science.gov (United States)

Zou, Y-X; Ruan, M-H; Luan, J; Feng, X; Chen, S; Chu, Z-Y

2017-01-01

This study investigated the effect of riboflavin on aging in Drosophila melanogaster (fruit fly). Experimental study. Naval Medical Research Institute. Fruit fly Drosophila melanogaster. After lifelong supplement of riboflavin, the lifespan and the reproduction of fruit flies were observed. Hydrogen peroxide (H2O2) was used to mimic oxidative stress damage to fruit flies and the survival time was recorded. The activity of copper-zinc-containing superoxide dismutase (SOD1), manganese containing SOD (SOD2) and catalase (CAT) and lipofuscin (LF) content were determined. Riboflavin significantly prolonged the lifespan (Log rank χ2=16.677, Priboflavin supplement. Riboflavin prolonged the lifespan and increased the reproduction of fruit flies through anti-oxidative stress pathway involving enhancing the activity of SOD1 and CAT and inhibiting LF accumulation. Riboflavin deserves more attention for slowing human aging.
Is Drosophila-microbe association species-specific or region specific? A study undertaken involving six Indian Drosophila species.

Science.gov (United States)

Singhal, Kopal; Khanna, Radhika; Mohanty, Sujata

2017-06-01

The present work aims to identify the microbial diversity associated with six Indian Drosophila species using next generation sequencing (NGS) technology and to discover the nature of their distribution across species and eco-geographic regions. Whole fly gDNA of six Drosophila species were used to generate sequences in an Illumina platform using NGS technology. De novo based assembled raw reads were blasted against the NR database of NCBI using BLASTn for identification of their bacterial loads. We have tried to include Drosophila species from different taxonomical groups and subgroups and from three different eco-climatic regions India; four species belong to Central India, while the rest two, D. melanogaster and D. ananassae, belong to West and South India to determine both their species-wise and region-wide distribution. We detected the presence of 33 bacterial genera across all six study species, predominated by the class Proteobacteria. Amongst all, D. melanogaster was found to be the most diverse by carrying around 85% of the bacterial diversity. Our findings infer both species-specific and environment-specific nature of the bacterial species inhabiting the Drosophila host. Though the present results are consistent with most of the earlier studies, they also remain incoherent with some. The present study outcome on the host-bacteria association and their species specific adaptation may provide some insight to understand the host-microbial interactions and the phenotypic implications of microbes on the host physiology. The knowledge gained may be importantly applied into the recent insect and pest population control strategy going to implement through gut microflora in India and abroad.
A genetic screen in Drosophila implicates Sex comb on midleg (Scm) in tissue overgrowth and mechanisms of Scm degradation by Wds.

Science.gov (United States)

Guo, Jiwei; Jin, Dan

2015-05-01

The sex comb on midleg (scm) gene encodes a transcriptional repressor and belongs to the Polycomb group (PcG) of genes, which regulates growth in Drosophila. Scm interacts with Polyhomeotic (a PcG protein) in vitro by recognizing its SPM domain. The homologous human protein, Sex comb on midleg-like 2 (Scml2), has been implicated in malignant brain tumors. Will die slowly (Wds) is another factor that regulates Drosophila development, and its homologous human protein, WD repeat domain 5(Wdr5), is part of the mixed lineage leukemia 1(MLL1) complex that promotes histone H3Lys4 methylation. Like Scml2, Wdr5 has been implicated in certain cancers; this protein plays an important role in leukemogenesis. In this study, we find that loss-of-function mutations in Scm result in non-autonomous tissue overgrowth in Drosophila, and determine that Scm is essential for ommatidium development and important for cell survival in Drosophila. Furthermore, our research suggests a relationship between Wds and Scm; Wds promotes Scm degradation through ubiquitination in vitro in Drosophila. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
The gene transformer-2 of Sciara (Diptera, Nematocera) and its effect on Drosophila sexual development.

Science.gov (United States)

Martín, Iker; Ruiz, María F; Sánchez, Lucas

2011-03-15

The gene transformer-2, which is involved in sex determination, has been studied in Drosophila, Musca, Ceratitis, Anastrepha and Lucilia. All these members of Diptera belong to the suborder Brachycera. In this work, it is reported the isolation and characterisation of genes transformer-2 of the dipterans Sciara ocellaris and Bradysia coprophila (formerly Sciara coprophila), which belong to the much less extensively analysed Sciaridae Family of the Suborder Nematocera, which is paraphyletic with respect to Suborder Brachycera. The transformer-2 genes of the studied Sciara species were found to be transcribed in both sexes during development and adult life, in both the soma and germ lines. They produced a single primary transcript, which follows the same alternative splicing in both sexes, giving rise to different mRNAs isoforms. In S. ocellaris the most abundant mRNA isoform encoded a full-length protein of 251 amino acids, while that of B. coprophila encoded a protein of 246 amino acids. Both showed the features of the SR protein family. The less significant mRNA isoforms of both species encoded truncated, presumably non-functional Transformer-2 proteins. The comparison of the functional Sciara Transformer-2 proteins among themselves and those of other insects revealed the greatest degree of conservation in the RRM domain and linker region. In contrast, the RS1 and RS2 domains showed extensive variation with respect to their number of amino acids and their arginine-serine (RS) dipeptide content. The expression of S. ocellaris Transformer-2 protein in Drosophila XX pseudomales lacking the endogenous transformer-2 function caused their partial feminisation. The transformer-2 genes of both Sciaridae species encode a single protein in both sexes that shares the characteristics of the Transformer-2 proteins of other insects. These proteins showed conserved sex-determination function in Drosophila; i.e., they were able to form a complex with the endogenous Drosophila
Calcium and Egg Activation in Drosophila

Science.gov (United States)

Sartain, Caroline V.; Wolfner, Mariana F.

2012-01-01

Summary In many animals, a rise in intracellular calcium levels is the trigger for egg activation, the process by which an arrested mature oocyte transitions to prepare for embryogenesis. In nearly all animals studied to date, this calcium rise, and thus egg activation, is triggered by the fertilizing sperm. However in the insects that have been examined, fertilization is not necessary to activate their oocytes. Rather, these insects’ eggs activate as they transit through the female’s reproductive tract, regardless of male contribution. Recent studies in Drosophila have shown that egg activation nevertheless requires calcium and that the downstream events and molecules of egg activation are also conserved, despite the difference in initial trigger. Genetic studies have uncovered essential roles for the calcium-dependent enzyme calcineurin and its regulator calcipressin, and have hinted at roles for calmodulin, in Drosophila egg activation. Physiological and in vitro studies have led to a model in which mechanical forces that impact the Drosophila oocyte as it moves through the reproductive tract triggers the influx of calcium from the external environment, thereby initiating egg activation. Future research will aim to test this model, as well as to determine the spatiotemporal dynamics of cytoplasmic calcium flux and mode of signal propagation in this unique system. PMID:23218670
Drosophila VAMP7 regulates Wingless intracellular trafficking.

Science.gov (United States)

Gao, Han; He, Fang; Lin, Xinhua; Wu, Yihui

2017-01-01

Drosophila Wingless (Wg) is a morphogen that determines cell fate during development. Previous studies have shown that endocytic pathways regulate Wg trafficking and signaling. Here, we showed that loss of vamp7, a gene required for vesicle fusion, dramatically increased Wg levels and decreased Wg signaling. Interestingly, we found that levels of Dally-like (Dlp), a glypican that can interact with Wg to suppress Wg signaling at the dorsoventral boundary of the Drosophila wing, were also increased in vamp7 mutant cells. Moreover, Wg puncta in Rab4-dependent recycling endosomes were Dlp positive. We hypothesize that VAMP7 is required for Wg intracellular trafficking and the accumulation of Wg in Rab4-dependent recycling endosomes might affect Wg signaling.
A novel Drosophila injury model reveals severed axons are cleared through a Draper/MMP-1 signaling cascade

Science.gov (United States)

Purice, Maria D; Ray, Arpita; Münzel, Eva Jolanda; Pope, Bernard J; Park, Daniel J; Speese, Sean D; Logan, Mary A

2017-01-01

Neural injury triggers swift responses from glia, including glial migration and phagocytic clearance of damaged neurons. The transcriptional programs governing these complex innate glial immune responses are still unclear. Here, we describe a novel injury assay in adult Drosophila that elicits widespread glial responses in the ventral nerve cord (VNC). We profiled injury-induced changes in VNC gene expression by RNA sequencing (RNA-seq) and found that responsive genes fall into diverse signaling classes. One factor, matrix metalloproteinase-1 (MMP-1), is induced in Drosophila ensheathing glia responding to severed axons. Interestingly, glial induction of MMP-1 requires the highly conserved engulfment receptor Draper, as well as AP-1 and STAT92E. In MMP-1 depleted flies, glia do not properly infiltrate neuropil regions after axotomy and, as a consequence, fail to clear degenerating axonal debris. This work identifies Draper-dependent activation of MMP-1 as a novel cascade required for proper glial clearance of severed axons. DOI: http://dx.doi.org/10.7554/eLife.23611.001 PMID:28825401
Drosophila as a model object in to study Chernobyl NPP after

International Nuclear Information System (INIS)

Marinenko, T.V.; Kozeretskaya, I.A.; Gorodetski, G.V.

2007-01-01

Complete text of publication follows. Water extractions of soil probes, which were selected on areas with different density of radioactive pollutions near Chernobyl exclusion zone ('Apple-tree garden' (Chernobyl); 'Island' (the bank of the pond-cooler of the Chernobyl nuclear power plant); 'Torch' (the area of revegetation near the Chernobyl nuclear power plant); 'Red forest' (side of a road) and 'Red forest' (edge of a forest)) were investigated. Dosimetric metering of all studied areas was conducted. γ- and β-activities of soil probes were determined by spectrometry and radiochemistry methods. The contents of trace elements in the soil probes of areas the 'Appletree garden' and 'Island' were determined. Water extractions from soil were prepared according to standard method (ratio - 1 : 2,5). The mutagenicity of water extractions of soil was estimated using the test of frequency of the sex-linked lethal mutations of Drosophila melanogaster. Water extractions were directly adds to a nourishing medium instead of standard component - distilled water. The strain of wild type of Drosophila Canton-S and natural populations of Drosophila from Pyriatin and Chernobyl were used in our study. The natural populations of Chernobyl and Pyriatin were included in study for more fully estimation of influence of factor on genetic processes of Drosophila, because of presence of unspecific adaptations of natural populations from radioactive polluted territories (as was shown before). According to dosimetric analysis data radiation activity of all water extractions of soils did not exceed a natural background. The probes of soil from areas the 'Red forest' and the 'Torch' were marked the higher activity; total activity of them was over 110 Mbk/kg. It is possibly that this fact was the reason of the absence of descendants in all variants of experiments conducted on medium with water extraction the 'Red forest' and in a variant of experiments concerned on study of activity of water
A damped oscillator imposes temporal order on posterior gap gene expression in Drosophila

Science.gov (United States)

Verd, Berta; Clark, Erik; Wotton, Karl R.; Janssens, Hilde; Jiménez-Guri, Eva; Crombach, Anton

2018-01-01

Insects determine their body segments in two different ways. Short-germband insects, such as the flour beetle Tribolium castaneum, use a molecular clock to establish segments sequentially. In contrast, long-germband insects, such as the vinegar fly Drosophila melanogaster, determine all segments simultaneously through a hierarchical cascade of gene regulation. Gap genes constitute the first layer of the Drosophila segmentation gene hierarchy, downstream of maternal gradients such as that of Caudal (Cad). We use data-driven mathematical modelling and phase space analysis to show that shifting gap domains in the posterior half of the Drosophila embryo are an emergent property of a robust damped oscillator mechanism, suggesting that the regulatory dynamics underlying long- and short-germband segmentation are much more similar than previously thought. In Tribolium, Cad has been proposed to modulate the frequency of the segmentation oscillator. Surprisingly, our simulations and experiments show that the shift rate of posterior gap domains is independent of maternal Cad levels in Drosophila. Our results suggest a novel evolutionary scenario for the short- to long-germband transition and help explain why this transition occurred convergently multiple times during the radiation of the holometabolan insects. PMID:29451884
Fipronil induces apoptosis through caspase-dependent mitochondrial pathways in Drosophila S2 cells.

Science.gov (United States)

Zhang, Baoyan; Xu, Zhiping; Zhang, Yixi; Shao, Xusheng; Xu, Xiaoyong; Cheng, Jiaogao; Li, Zhong

2015-03-01

Fipronil is the first phenylpyrazole insecticide widely used in controlling pests, including pyrethroid, organophosphate and carbamate insecticides. It is generally accepted that fipronil elicits neurotoxicity via interactions with GABA and glutamate receptors, although alternative mechanisms have recently been proposed. This study evaluates the genotoxicity of fipronil and its likely mode of action in Drosophila S2 cells, as an in vitro model. Fipronil administrated the concentration- and time-dependent S2 cell proliferation. Intracellular biochemical assays showed that fipronil-induced S2 cell apoptosis coincided with a decrease in the mitochondrial membrane potential and an increase reactive oxygen species generation, a significant decrease of Bcl-2 and DIAP1, and a marked augmentation of Cyt c and caspase-3. Because caspase-3 is the major executioner caspase downstream of caspase-9 in Drosophila, enzyme activity assays were used to determine the activities of caspase-3 and caspase-9. Our results indicated that fipronil effectively induced apoptosis in Drosophila S2 cells through caspase-dependent mitochondrial pathways. Copyright © 2015 Elsevier Inc. All rights reserved.
A non-redundant role for Drosophila Mkk4 and hemipterous/Mkk7 in TAK1-mediated activation of JNK.

Directory of Open Access Journals (Sweden)

Peter Geuking

Full Text Available BACKGROUND: The JNK pathway is a mitogen-activated protein (MAP kinase pathway involved in the regulation of numerous physiological processes during development and in response to environmental stress. JNK activity is controlled by two MAPK kinases (MAPKK, Mkk4 and Mkk7. Mkk7 plays a prominent role upon Tumor Necrosis Factor (TNF stimulation. Eiger, the unique TNF-superfamily ligand in Drosophila, potently activates JNK signaling through the activation of the MAPKKK Tak1. METHODOLOGY/PRINCIPAL FINDINGS: In a dominant suppressor screen for new components of the Eiger/JNK-pathway in Drosophila, we have identified an allelic series of the Mkk4 gene. Our genetic and biochemical results demonstrate that Mkk4 is dispensable for normal development and host resistance to systemic bacterial infection but plays a non-redundant role as a MAPKK acting in parallel to Hemipterous/Mkk7 in dTAK1-mediated JNK activation upon Eiger and Imd pathway activation. CONCLUSIONS/SIGNIFICANCE: In contrast to mammals, it seems that in Drosophila both MAPKKs, Hep/Mkk7 and Mkk4, are required to induce JNK upon TNF or pro-inflammatory stimulation.
The D1 family dopamine receptor, DopR, potentiates hind leg grooming behavior in Drosophila.

Science.gov (United States)

Pitmon, E; Stephens, G; Parkhurst, S J; Wolf, F W; Kehne, G; Taylor, M; Lebestky, T

2016-03-01

Drosophila groom away debris and pathogens from the body using their legs in a stereotyped sequence of innate motor behaviors. Here, we investigated one aspect of the grooming repertoire by characterizing the D1 family dopamine receptor, DopR. Removal of DopR results in decreased hind leg grooming, as substantiated by quantitation of dye remaining on mutant and RNAi animals vs. controls and direct scoring of behavioral events. These data are also supported by pharmacological results that D1 receptor agonists fail to potentiate grooming behaviors in headless DopR flies. DopR protein is broadly expressed in the neuropil of the thoracic ganglion and overlaps with TH-positive dopaminergic neurons. Broad neuronal expression of dopamine receptor in mutant animals restored normal grooming behaviors. These data provide evidence for the role of DopR in potentiating hind leg grooming behaviors in the thoracic ganglion of adult Drosophila. This is a remarkable juxtaposition to the considerable role of D1 family dopamine receptors in rodent grooming, and future investigations of evolutionary relationships of circuitry may be warranted. © 2016 The Authors. Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.
The role of the Drosophila LAMMER protein kinase DOA in somatic ...

Indian Academy of Sciences (India)

2010-09-06

Sep 6, 2010 ... Somatic sexual identity in Drosophila melanogaster is under the control of a ... between stages 12 and 14, in response to an X to autosome .... MER kinases used were Drosophila DOA, mouse CLK1, human CLK2 and.
Metabolomic Studies in Drosophila.

Science.gov (United States)

Cox, James E; Thummel, Carl S; Tennessen, Jason M

2017-07-01

Metabolomic analysis provides a powerful new tool for studies of Drosophila physiology. This approach allows investigators to detect thousands of chemical compounds in a single sample, representing the combined contributions of gene expression, enzyme activity, and environmental context. Metabolomics has been used for a wide range of studies in Drosophila , often providing new insights into gene function and metabolic state that could not be obtained using any other approach. In this review, we survey the uses of metabolomic analysis since its entry into the field. We also cover the major methods used for metabolomic studies in Drosophila and highlight new directions for future research. Copyright © 2017 by the Genetics Society of America.

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

International Nuclear Information System (INIS)

Lee, Shin-Hae; Park, Joung-Sun; Kim, Young-Shin; Chung, Hae-Young; Yoo, Mi-Ae

2012-01-01

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.
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.
A Drosophila Model to Image Phagosome Maturation

Directory of Open Access Journals (Sweden)

Douglas A. Brooks

2013-03-01

Full Text Available Phagocytosis involves the internalization of extracellular material by invagination of the plasma membrane to form intracellular vesicles called phagosomes, which have functions that include pathogen degradation. The degradative properties of phagosomes are thought to be conferred by sequential fusion with endosomes and lysosomes; however, this maturation process has not been studied in vivo. We employed Drosophila hemocytes, which are similar to mammalian professional macrophages, to establish a model of phagosome maturation. Adult Drosophila females, carrying transgenic Rab7-GFP endosome and Lamp1-GFP lysosome markers, were injected with E. coli DH5α and the hemocytes were collected at 15, 30, 45 and 60 minutes after infection. In wild-type females, E. coli were detected within enlarged Rab7-GFP positive phagosomes at 15 to 45 minutes after infection; and were also observed in enlarged Lamp1-GFP positive phagolysosomes at 45 minutes. Two-photon imaging of hemocytes in vivo confirmed this vesicle morphology, including enlargement of Rab7-GFP and Lamp1-GFP structures that often appeared to protrude from hemocytes. The interaction of endosomes and lysosomes with E. coli phagosomes observed in Drosophila hemocytes was consistent with that previously described for phagosome maturation in human ex vivo macrophages. We also tested our model as a tool for genetic analysis using 14-3-3e mutants, and demonstrated altered phagosome maturation with delayed E. coli internalization, trafficking and/or degradation. These findings demonstrate that Drosophila hemocytes provide an appropriate, genetically amenable, model for analyzing phagosome maturation ex vivo and in vivo.
Use of Drosophila to study DNA repair

International Nuclear Information System (INIS)

Boyd, J.B.; Harris, P.V.; Sakaguchi, K.

1988-01-01

This paper discusses Drosophila, the premier metazoan organism for analyzing many fundamental features of eukaryotic gene regulation. The authors present adaptations of several approaches for studying DNA repair to an analysis of repair-defective mutants in Drosophila. A current understanding of Drosophila DNA repair is described
TORC1 Inhibition by Rapamycin Promotes Antioxidant Defences in a Drosophila Model of Friedreich's Ataxia.

Directory of Open Access Journals (Sweden)

Pablo Calap-Quintana

Full Text Available Friedreich's ataxia (FRDA, the most common inherited ataxia in the Caucasian population, is a multisystemic disease caused by a significant decrease in the frataxin level. To identify genes capable of modifying the severity of the symptoms of frataxin depletion, we performed a candidate genetic screen in a Drosophila RNAi-based model of FRDA. We found that genetic reduction in TOR Complex 1 (TORC1 signalling improves the impaired motor performance phenotype of FRDA model flies. Pharmacologic inhibition of TORC1 signalling by rapamycin also restored this phenotype and increased the lifespan and ATP levels. Furthermore, rapamycin reduced the altered levels of malondialdehyde + 4-hydroxyalkenals and total glutathione of the model flies. The rapamycin-mediated protection against oxidative stress is due in part to an increase in the transcription of antioxidant genes mediated by cap-n-collar (Drosophila ortholog of Nrf2. Our results suggest that autophagy is indeed necessary for the protective effect of rapamycin in hyperoxia. Rapamycin increased the survival and aconitase activity of model flies subjected to high oxidative insult, and this improvement was abolished by the autophagy inhibitor 3-methyladenine. These results point to the TORC1 pathway as a new potential therapeutic target for FRDA and as a guide to finding new promising molecules for disease treatment.
Acute and long-term outcomes in a Drosophila melanogaster model of classic galactosemia occur independently of galactose-1-phosphate accumulation

Directory of Open Access Journals (Sweden)

Jennifer M. I. Daenzer

2016-11-01

Full Text Available Classic galactosemia (CG is a potentially lethal inborn error of metabolism that results from the profound loss of galactose-1-phosphate uridylyltransferase (GALT, the second enzyme in the Leloir pathway of galactose metabolism. Neonatal detection and dietary restriction of galactose minimizes or resolves the acute sequelae of CG, but fails to prevent the long-term complications experienced by a majority of patients. One of the substrates of GALT, galactose-1-phosphate (Gal-1P, accumulates to high levels in affected infants, especially following milk exposure, and has been proposed as the key mediator of acute and long-term pathophysiology in CG. However, studies of treated patients demonstrate no association between red blood cell Gal-1P level and long-term outcome severity. Here, we used genetic, epigenetic and environmental manipulations of a Drosophila melanogaster model of CG to test the role of Gal-1P as a candidate mediator of outcome in GALT deficiency. Specifically, we both deleted and knocked down the gene encoding galactokinase (GALK in control and GALT-null Drosophila, and assessed the acute and long-term outcomes of the resulting animals in the presence and absence of dietary galactose. GALK is the first enzyme in the Leloir pathway of galactose metabolism and is responsible for generating Gal-1P in humans and Drosophila. Our data confirmed that, as expected, loss of GALK lowered or eliminated Gal-1P accumulation in GALT-null animals. However, we saw no concomitant rescue of larval survival or adult climbing or fecundity phenotypes. Instead, we saw that loss of GALK itself was not benign and in some cases phenocopied or exacerbated the outcome seen in GALT-null animals. These findings strongly contradict the long-standing hypothesis that Gal-1P alone underlies pathophysiology of acute and long-term outcomes in GALT-null Drosophila and suggests that other metabolite(s of galactose, and/or other pathogenic factors, might be involved.
Transcripts of mobile element MDG1 during ontogenesis of Drosophila melanogaster

International Nuclear Information System (INIS)

Kuvakina, A.I.; Nurminskii, D.I.; Kogan, G.L.; Gvozdev, V.A.

1989-01-01

It has been demonstrated by Northern hybridization using a single-stranded labeled probes that the number of MDG1 transcripts as well as their size change during ontogenesis of Drosophila. The transcripts of MDG1 were not found in unfertilized eggs. The full-length transcript of MDG1 (about 7 kb long) appears in the embryonic and larval cells, and its quantity sharply increases in pupae and adults. A transcript of about 5 kb length is also found in the pupae and adults. Another, about 2 kb long transcript forms in the embryos, pupae and adults, which is absent in larvae. The main transcript in the larval cells, complementary to the inner part of the body of MDG1, is about 1 kb long. The transcription level of MDG1 and the mobile element copia do not change under heat shock at adult stage
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......,313 SAGE tags from transcripts expressed in Drosophila embryonic, larval, pupae, adult, and testicular tissue. From these SAGE tags, we identified 40,823 unique SAGE tags. Our analysis showed that 55% of the 40,823 unique SAGE tags are novel without matches in currently known Drosophila transcripts...... in the Drosophila genome. Our study reveals the presence of a significant number of novel low-abundant transcripts in Drosophila, and highlights the need to isolate these novel low-abundant transcripts for further biological studies. Udgivelsesdato: 2005-Jun...
Drosophila acetylcholinesterase: demonstration of a glycoinositol phospholipid anchor and an endogenous proteolytic cleavage

International Nuclear Information System (INIS)

Haas, R.; Marshall, T.L.; Rosenberry, T.L.

1988-01-01

The presence of a glycoinositol phospholipid anchor Drosophila acetylcholinesterase (AChE) was shown by several criteria. Chemical analysis of highly purified Drosophila AChE demonstrated approximately one residue of inositol per enzyme subunit. Selective cleavage by Staphylococcus aureus phosphatidylinositol-specific phospholipase C (PI-PLC) was tested with Drosophila AChE radiolabeled by the photoactivatable affinity probe 3-(trifluoromethyl)-3-(m-[ 125 I]iodophenyl)diazirine ([ 125 I]TID), a reagent that specifically labels the lipid moiety of glycoinositol phospholipid-anchored proteins. Digestion with PI-PLC released 75% of this radiolabel from the protein. Gel electrophoresis of Drosophila AChE in sodium dodecyl sulfate indicated prominent 55- and 16-kDa bands and a faint 70-kDa band. The [ 125 ]I]TID label was localized on the 55-kDa fragment, suggesting that this fragment is the C-terminal portion of the protein. In support of this conclusion, a sensitive microsequencing procedure that involved manual Edman degradation combined with radiomethylation was used to determine residues 2-5 of the 16-kDa fragment. Comparison with the Drosophila AChE cDNA sequence confirmed that the 16-kDa fragment includes the N-terminus of AChE. Furthermore, the position of the N-terminal amino acid of the mature Drosophila AChE is closely homologous to that of Torpedo AChE. The presence of radiomethylatable ethanolamine in both 16- and 55-kDa fragments was also confirmed. Thus, Drosophila AChE may include a second posttranslational modification involving ethanolamine
Notch-dependent epithelial fold determines boundary formation between developmental fields in the Drosophila antenna.

Science.gov (United States)

Ku, Hui-Yu; Sun, Y Henry

2017-07-01

Compartment boundary formation plays an important role in development by separating adjacent developmental fields. Drosophila imaginal discs have proven valuable for studying the mechanisms of boundary formation. We studied the boundary separating the proximal A1 segment and the distal segments, defined respectively by Lim1 and Dll expression in the eye-antenna disc. Sharp segregation of the Lim1 and Dll expression domains precedes activation of Notch at the Dll/Lim1 interface. By repressing bantam miRNA and elevating the actin regulator Enable, Notch signaling then induces actomyosin-dependent apical constriction and epithelial fold. Disruption of Notch signaling or the actomyosin network reduces apical constriction and epithelial fold, so that Dll and Lim1 cells become intermingled. Our results demonstrate a new mechanism of boundary formation by actomyosin-dependent tissue folding, which provides a physical barrier to prevent mixing of cells from adjacent developmental fields.
Prevention and Treatment of Vitamin D and Calcium Deficiency in Children and Adolescents: Indian Academy of Pediatrics (IAP) Guidelines.

Science.gov (United States)

Khadilkar, Anuradha; Khadilkar, Vaman; Chinnappa, Jagdish; Rathi, Narendra; Khadgawat, Rajesh; Balasubramanian, S; Parekh, Bakul; Jog, Pramod

2017-07-15

Vitamin D deficiency (VDD) is being increasingly reported from India from all age-groups. Reports suggest that VDD affects all age groups, from neonates to adolescents. Further, habitually low calcium intakes are also reported in Indian children. Given the multiple guidelines, peculiarities of Indian circumstances, changing lifestyles, and lack of fortification, the Indian Academy of Pediatrics (IAP) felt the need for a Practice Guideline for Pediatricians for the prevention and treatment of vitamin D and calcium deficiency in children and adolescents. The 'Guideline for Vitamin D and Calcium in Children' committee was formed by the IAP in September 2016. A consultative committee meeting was held in November 2016 in Mumbai. Evidence from Indian and international studies and other previous published recommendations, which were pertinent to the Indian circumstances, were collated for the preparation of these guidelines. To present a practice guideline for pediatricians for the prevention and treatment of deficiency of vitamin D and calcium in the Indian context. For the prevention of rickets in premature infants, 400 IU of vitamin D and 150-220 mg/kg of calcium, and in neonates, 400 IU of vitamin D and 200 mg of calcium are recommended daily. For prevention of rickets and hypocalcemia in infants (after neonatal period) upto 1 year of age, and from 1-18 years, 400 IU and 600 IU vitamin D/day and 250-500 mg/day and 600-800 mg/day of calcium, respectively, are recommended. For treatment of rickets in premature neonates, infants upto 1 year and from 1-18 years, 1000 IU, 2000 IU and 3000-6000 IU of vitamin D daily, respectively, and elemental calcium of 70-80 mg/kg/day in premature neonates and 500-800 mg daily for all children over that age are recommended. Larger doses of vitamin D may be given from 3 months to 18 years of age as 60,000 IU/week for 6 weeks.
The molecular mechanisms of OPA1-mediated optic atrophy in Drosophila model and prospects for antioxidant treatment.

Directory of Open Access Journals (Sweden)

Will Yarosh

2008-01-01

Full Text Available Mutations in optic atrophy 1 (OPA1, a nuclear gene encoding a mitochondrial protein, is the most common cause for autosomal dominant optic atrophy (DOA. The condition is characterized by gradual loss of vision, color vision defects, and temporal optic pallor. To understand the molecular mechanism by which OPA1 mutations cause optic atrophy and to facilitate the development of an effective therapeutic agent for optic atrophies, we analyzed phenotypes in the developing and adult Drosophila eyes produced by mutant dOpa1 (CG8479, a Drosophila ortholog of human OPA1. Heterozygous mutation of dOpa1 by a P-element or transposon insertions causes no discernable eye phenotype, whereas the homozygous mutation results in embryonic lethality. Using powerful Drosophila genetic techniques, we created eye-specific somatic clones. The somatic homozygous mutation of dOpa1 in the eyes caused rough (mispatterning and glossy (decreased lens and pigment deposition eye phenotypes in adult flies; this phenotype was reversible by precise excision of the inserted P-element. Furthermore, we show the rough eye phenotype is caused by the loss of hexagonal lattice cells in developing eyes, suggesting an increase in lattice cell apoptosis. In adult flies, the dOpa1 mutation caused an increase in reactive oxygen species (ROS production as well as mitochondrial fragmentation associated with loss and damage of the cone and pigment cells. We show that superoxide dismutase 1 (SOD1, Vitamin E, and genetically overexpressed human SOD1 (hSOD1 is able to reverse the glossy eye phenotype of dOPA1 mutant large clones, further suggesting that ROS play an important role in cone and pigment cell death. Our results show dOpa1 mutations cause cell loss by two distinct pathogenic pathways. This study provides novel insights into the pathogenesis of optic atrophy and demonstrates the promise of antioxidants as therapeutic agents for this condition.
Ebi/AP-1 suppresses pro-apoptotic genes expression and permits long-term survival of Drosophila sensory neurons.

Directory of Open Access Journals (Sweden)

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.
Hearing regulates Drosophila aggression.

Science.gov (United States)

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

2017-02-21

Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melanogaster to identify hearing as an important sensory modality in the context of intermale aggressive behavior. We demonstrate that neuronal silencing and targeted knockdown of hearing genes in the fly's auditory organ elicit abnormal aggression. Further, we show that exposure to courtship or aggression song has opposite effects on aggression. Our data define the importance of hearing in the control of Drosophila intermale aggression and open perspectives to decipher how hearing and other sensory modalities are integrated at the neural circuit level.
Two Components of Aversive Memory in Drosophila, Anesthesia-Sensitive and Anesthesia-Resistant Memory, Require Distinct Domains Within the Rgk1 Small GTPase.

Science.gov (United States)

Murakami, Satoshi; Minami-Ohtsubo, Maki; Nakato, Ryuichiro; Shirahige, Katsuhiko; Tabata, Tetsuya

2017-05-31

Multiple components have been identified that exhibit different stabilities for aversive olfactory memory in Drosophila These components have been defined by behavioral and genetic studies and genes specifically required for a specific component have also been identified. Intermediate-term memory generated after single cycle conditioning is divided into anesthesia-sensitive memory (ASM) and anesthesia-resistant memory (ARM), with the latter being more stable. We determined that the ASM and ARM pathways converged on the Rgk1 small GTPase and that the N-terminal domain-deleted Rgk1 was sufficient for ASM formation, whereas the full-length form was required for ARM formation. Rgk1 is specifically accumulated at the synaptic site of the Kenyon cells (KCs), the intrinsic neurons of the mushroom bodies, which play a pivotal role in olfactory memory formation. A higher than normal Rgk1 level enhanced memory retention, which is consistent with the result that Rgk1 suppressed Rac-dependent memory decay; these findings suggest that rgk1 bolsters ASM via the suppression of forgetting. We propose that Rgk1 plays a pivotal role in the regulation of memory stabilization by serving as a molecular node that resides at KC synapses, where the ASM and ARM pathway may interact. SIGNIFICANCE STATEMENT Memory consists of multiple components. Drosophila olfactory memory serves as a fundamental model with which to investigate the mechanisms that underlie memory formation and has provided genetic and molecular means to identify the components of memory, namely short-term, intermediate-term, and long-term memory, depending on how long the memory lasts. Intermediate memory is further divided into anesthesia-sensitive memory (ASM) and anesthesia-resistant memory (ARM), with the latter being more stable. We have identified a small GTPase in Drosophila , Rgk1, which plays a pivotal role in the regulation of olfactory memory stability. Rgk1 is required for both ASM and ARM. Moreover, N
Water SA - Vol 33, No 1 (2007)

African Journals Online (AJOL)

Determining a charge for the clearing of invasive alien plant species (IAPs) to augment water supply in South Africa · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. JN Blignaut, C Marais, JK Turpie. http://dx.doi.org/10.4314/wsa.v33i1.47868 ...
Mapping Linked Genes in "Drosophila Melanogaster" Using Data from the F2 Generation of a Dihybrid Cross

Science.gov (United States)

Marshall, Pamela A.

2008-01-01

"Drosophila melanogaster" is a commonly utilized organism for testing hypotheses about inheritance of traits. Students in both high school and university labs study the genetics of inheritance by analyzing offspring of appropriate "Drosophila" crosses to determine inheritance patterns, including gene linkage. However, most genetics investigations…
Vitellogenin family gene expression does not increase Drosophila lifespan or fecundity [v1; ref status: indexed, http://f1000r.es/3ac

Directory of Open Access Journals (Sweden)

Yingxue Ren

2014-06-01

Full Text Available One of the most striking patterns in comparative biology is the negative correlation between lifespan and fecundity observed in comparisons among species. This pattern is consistent with the idea that organisms need to allocate a fixed energy budget among competing demands of growth, development, reproduction and somatic maintenance. However, exceptions to this pattern have been observed in many social insects, including ants, bees, and termites. In honey bees (Apis mellifera, Vitellogenin (Vg, a yolk protein precursor, has been implicated in mediating the long lifespan and high fecundity of queen bees. To determine if Vg-like proteins can regulate lifespan in insects generally, we examined the effects of expression of Apis Vg and Drosophila CG31150 (a Vg-like gene recently identified as cv-d on Drosophila melanogaster lifespan and fecundity using the RU486-inducible GeneSwitch system. For all genotypes tested, overexpression of Vg and CG31150 decreased Drosophila lifespan and did not affect total or age-specific fecundity. We also detected an apparent effect of the GeneSwitch system itself, wherein RU486 exposure (or the GAL4 expression it induces led to a significant increase in longevity and decrease in fecundity in our fly strains. This result is consistent with the pattern reported in a recent meta-analysis of Drosophila aging studies, where transgenic constructs of the UAS/GAL4 expression system that should have no effect (e.g. an uninduced GeneSwitch significantly extended lifespan in some genetic backgrounds. Our results suggest that Vg-family genes are not major regulators of Drosophila life history traits, and highlight the importance of using appropriate controls in aging studies.
Snipper, an Eri1 homologue, affects histone mRNA abundance and is crucial for normal Drosophila melanogaster development.

Science.gov (United States)

Alexiadis, Anastasios; Delidakis, Christos; Kalantidis, Kriton

2017-07-01

The conserved 3'-5' RNA exonuclease ERI1 is implicated in RNA interference inhibition, 5.8S rRNA maturation and histone mRNA maturation and turnover. The single ERI1 homologue in Drosophila melanogaster Snipper (Snp) is a 3'-5' exonuclease, but its in vivo function remains elusive. Here, we report Snp requirement for normal Drosophila development, since its perturbation leads to larval arrest and tissue-specific downregulation results in abnormal tissue development. Additionally, Snp directly interacts with histone mRNA, and its depletion results in drastic reduction in histone transcript levels. We propose that Snp protects the 3'-ends of histone mRNAs and upon its absence, histone transcripts are readily degraded. This in turn may lead to cell cycle delay or arrest, causing growth arrest and developmental perturbations. © 2017 Federation of European Biochemical Societies.
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.

P1-10: The Association between Colors and Emotions

Directory of Open Access Journals (Sweden)

Yen-Yu Chen

2012-10-01

Full Text Available Wexner (1954 Journal of Applied Psychology 38 432–435 demonstrated colors were associated with specific emotions. Colors have many meanings, such as that red can lead to induce positive or negative emotions (Kaya & Epps, 2011 College Student Journal 38 396–406. This study extends previous findings and aims to investigate two questions, (1 whether colors are associated with the emotions of pictures in IAPS (International Affective Picture System and (2 whether perceiving IAPS consciously and unconsciously has different emotion associations. We replaced facial expressions with pictures of IAPS as stimuli. Five colors (black, red, yellow, blue, and white and 3 categories of IAPS (fear, awe, and amusement were manipulated in this study. Pictures were displayed in different durations to manipulate conscious (250 ms and unconscious (33 ms visual stimuli (Manuel & Pedro, 2009 Behavior Research Method 41 184–191 in two experiments. Participants were required to select the most suitable color at their first glance when the pictures of IAPS were presented, and vice versa. Results showed that overall association between colors and pictures of IAPS was weak but the association pattern was meaningful. It concluded (1 black and red colors are associated with the fearful emotion, and blue color is associated with the happy emotion; (2 white colors do not associate with the fear emotion, which is incongruent with the previous study (Osvaldo & Paul, 2007 Colour: Design & Creativity 1 1–20; (3 participants did not perform differently between conscious and unconscious stimulus conditions.
A comparison of Frost expression among species and life stages of Drosophila.

Science.gov (United States)

Bing, X; Zhang, J; Sinclair, Brent J

2012-02-01

Frost (Fst) is a gene associated with cold exposure in Drosophila melanogaster. We used real-time PCR to assess whether cold exposure induces expression of Fst in 10 different life stages of D. melanogaster, and adults of seven other Drosophila species. We exposed groups of individuals to 0 °C (2 h), followed by 1 h recovery (22 °C). Frost was significantly upregulated in response to cold in eggs, third instar larvae, and 2- and 5-day-old male and female adults in D. melanogaster. Life stages in which cold did not upregulate Fst had high constitutive expression. Frost is located on the opposite strand of an intron of Diuretic hormone (DH), but cold exposure did not upregulate DH. Frost orthologues were identified in six other species within the Melanogaster group (Drosophila sechellia, Drosophila simulans, Drosophila yakuba, Drosophila erecta, Drosophila ananassae and Drosophila mauritiana). Frost orthologues were upregulated in response to cold exposure in both sexes in adults of all of these species. The predicted structure of a putative Frost consensus protein shows highly conserved tandem repeats of motifs involved in cell signalling (PEST and TRAF2), suggesting that Fst might encode an adaptor protein involved in acute stress or apoptosis signalling in vivo. © 2011 The Authors. Insect Molecular Biology © 2011 The Royal Entomological Society.
Microtubule–microtubule sliding by kinesin-1 is essential for normal cytoplasmic streaming in Drosophila oocytes

Science.gov (United States)

Lu, Wen; Winding, Michael; Lakonishok, Margot; Wildonger, Jill

2016-01-01

Cytoplasmic streaming in Drosophila oocytes is a microtubule-based bulk cytoplasmic movement. Streaming efficiently circulates and localizes mRNAs and proteins deposited by the nurse cells across the oocyte. This movement is driven by kinesin-1, a major microtubule motor. Recently, we have shown that kinesin-1 heavy chain (KHC) can transport one microtubule on another microtubule, thus driving microtubule–microtubule sliding in multiple cell types. To study the role of microtubule sliding in oocyte cytoplasmic streaming, we used a Khc mutant that is deficient in microtubule sliding but able to transport a majority of cargoes. We demonstrated that streaming is reduced by genomic replacement of wild-type Khc with this sliding-deficient mutant. Streaming can be fully rescued by wild-type KHC and partially rescued by a chimeric motor that cannot move organelles but is active in microtubule sliding. Consistent with these data, we identified two populations of microtubules in fast-streaming oocytes: a network of stable microtubules anchored to the actin cortex and free cytoplasmic microtubules that moved in the ooplasm. We further demonstrated that the reduced streaming in sliding-deficient oocytes resulted in posterior determination defects. Together, we propose that kinesin-1 slides free cytoplasmic microtubules against cortically immobilized microtubules, generating forces that contribute to cytoplasmic streaming and are essential for the refinement of posterior determinants. PMID:27512034
A Drosophila wing spot test

International Nuclear Information System (INIS)

Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

1986-01-01

A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)
Effect of non-nutritive sugars to decrease the survivorship of spotted wing drosophila, Drosophila suzukii

Science.gov (United States)

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

Science.gov (United States)

Weir, Peter T; Dickinson, Michael H

2012-01-10

Insects maintain a constant bearing across a wide range of spatial scales. Monarch butterflies and locusts traverse continents [1, 2], and foraging bees and ants travel hundreds of meters to return to their nests [1, 3, 4], whereas many other insects fly straight for only a few centimeters before changing direction. Despite this variation in spatial scale, the brain region thought to underlie long-distance navigation is remarkably conserved [5, 6], suggesting that the use of a celestial compass is a general and perhaps ancient capability of insects. Laboratory studies of Drosophila have identified a local search mode in which short, straight segments are interspersed with rapid turns [7, 8]. However, this flight mode is inconsistent with measured gene flow between geographically separated populations [9-11], and individual Drosophila can travel 10 km across desert terrain in a single night [9, 12, 13]-a feat that would be impossible without prolonged periods of straight flight. To directly examine orientation behavior under outdoor conditions, we built a portable flight arena in which a fly viewed the natural sky through a liquid crystal device that could experimentally rotate the polarization angle. Our findings indicate that Drosophila actively orient using the sky's natural polarization pattern. Copyright © 2012 Elsevier Ltd. All rights reserved.
mutations of Drosophila melanogaster cause nonrandom cell death ...

Indian Academy of Sciences (India)

In Drosophila melanogaster, the intersex (ix) is a terminally positioned gene in somatic sex determination hierarchy and function with the female specific product of double sex (DSXF) to implement female sexual differentiation. The null phenotype of ix is to transform diplo-X individuals into intersexes while leaving haplo-X ...
Org-1, the Drosophila ortholog of Tbx1, is a direct activator of known identity genes during muscle specification.

Science.gov (United States)

Schaub, Christoph; Nagaso, Hideyuki; Jin, Hong; Frasch, Manfred

2012-03-01

Members of the T-Box gene family of transcription factors are important players in regulatory circuits that generate myogenic and cardiogenic lineage diversities in vertebrates. We show that during somatic myogenesis in Drosophila, the single ortholog of vertebrate Tbx1, optomotor-blind-related-gene-1 (org-1), is expressed in a small subset of muscle progenitors, founder cells and adult muscle precursors, where it overlaps with the products of the muscle identity genes ladybird (lb) and slouch (slou). In addition, org-1 is expressed in the lineage of the heart-associated alary muscles. org-1 null mutant embryos lack Lb and Slou expression within the muscle lineages that normally co-express org-1. As a consequence, the respective muscle fibers and adult muscle precursors are either severely malformed or missing, as are the alary muscles. To address the mechanisms that mediate these regulatory interactions between Org-1, Lb and Slou, we characterized distinct enhancers associated with somatic muscle expression of lb and slou. We demonstrate that these lineage- and stage-specific cis-regulatory modules (CRMs) bind Org-1 in vivo, respond to org-1 genetically and require T-box domain binding sites for their activation. In summary, we propose that org-1 is a common and direct upstream regulator of slou and lb in the developmental pathway of these two neighboring muscle lineages. Cross-repression between slou and lb and combinatorial activation of lineage-specific targets by Org-1-Slou and Org-1-Lb, respectively, then leads to the distinction between the two lineages. These findings provide new insights into the regulatory circuits that control the proper pattering of the larval somatic musculature in Drosophila.
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.
Control of G1 in the developing Drosophila eye: rca1 regulates Cyclin A.

Science.gov (United States)

Dong, X; Zavitz, K H; Thomas, B J; Lin, M; Campbell, S; Zipursky, S L

1997-01-01

In the developing eye of Drosophila melanogaster, cells become synchronized in the G1 phase of the cell cycle just prior to the onset of cellular differentiation and morphogenesis. In roughex (rux) mutants, cells enter S phase precociously because of ectopic activation of a Cyclin A/Cdk complex in early G1. This leads to defects in cell fate and pattern formation, and results in abnormalities in the morphology of the adult eye. A screen for dominant suppressors of the rux eye phenotype led to the identification of mutations in cyclin A, string (cdc25), and new cell cycle genes. One of these genes, regulator of cyclin A (rca1), encodes a novel protein required for both mitotic and meiotic cell cycle progression. rca1 mutants arrest in G2 of embryonic cell cycle 16 with a phenotype very similar to cyclin A loss of function mutants. Expression of rca1 transgenes in G1 or in postmitotic neurons promotes Cyclin A protein accumulation and drives cells into S phase in a Cyclin A-dependent fashion.
Glucuronylated core 1 glycans are required for precise localization of neuromuscular junctions and normal formation of basement membranes on Drosophila muscles.

Science.gov (United States)

Itoh, Kazuyoshi; Akimoto, Yoshihiro; Kondo, Shu; Ichimiya, Tomomi; Aoki, Kazuhiro; Tiemeyer, Michael; Nishihara, Shoko

2018-04-15

T antigen (Galβ1-3GalNAcα1-Ser/Thr) is an evolutionary-conserved mucin-type core 1 glycan structure in animals synthesized by core 1 β1,3-galactosyltransferase 1 (C1GalT1). Previous studies showed that T antigen produced by Drosophila C1GalT1 (dC1GalT1) was expressed in various tissues and dC1GalT1 loss in larvae led to various defects, including decreased number of circulating hemocytes, hyper-differentiation of hematopoietic stem cells in lymph glands, malformation of the central nervous system, mislocalization of neuromuscular junction (NMJ) boutons, and ultrastructural abnormalities in NMJs and muscle cells. Although glucuronylated T antigen (GlcAβ1-3Galβ1-3GalNAcα1-Ser/Thr) has been identified in Drosophila, the physiological function of this structure has not yet been clarified. In this study, for the first time, we unraveled biological roles of glucuronylated T antigen. Our data show that in Drosophila, glucuronylation of T antigen is predominantly carried out by Drosophila β1,3-glucuronyltransferase-P (dGlcAT-P). We created dGlcAT-P null mutants and found that mutant larvae showed lower expression of glucuronylated T antigen on the muscles and at NMJs. Furthermore, mislocalization of NMJ boutons and a partial loss of the basement membrane components collagen IV (Col IV) and nidogen (Ndg) at the muscle 6/7 boundary were observed. Those two phenotypes were correlated and identical to previously described phenotypes in dC1GalT1 mutant larvae. In addition, dGlcAT-P null mutants exhibited fewer NMJ branches on muscles 6/7. Moreover, ultrastructural analysis revealed that basement membranes that lacked Col IV and Ndg were significantly deformed. We also found that the loss of dGlcAT-P expression caused ultrastructural defects in NMJ boutons. Finally, we showed a genetic interaction between dGlcAT-P and dC1GalT1. Therefore, these results demonstrate that glucuronylated core 1 glycans synthesized by dGlcAT-P are key modulators of NMJ bouton localization
The Drosophila HEM-2/NAP1 homolog KETTE controls axonal pathfinding and cytoskeletal organization.

Science.gov (United States)

Hummel, T; Leifker, K; Klämbt, C

2000-04-01

In Drosophila, the correct formation of the segmental commissures depends on neuron-glial interactions at the midline. The VUM midline neurons extend axons along which glial cells migrate in between anterior and posterior commissures. Here, we show that the gene kette is required for the normal projection of the VUM axons and subsequently disrupts glial migration. Axonal projection defects are also found for many other moto- and interneurons. In addition, kette affects the cell morphology of mesodermal and epidermal derivatives, which show an abnormal actin cytoskeleton. The KETTE protein is homologous to the transmembrane protein HEM-2/NAP1 evolutionary conserved from worms to vertebrates. In vitro analysis has shown a specific interaction of the vertebrate HEM-2/NAP1 with the SH2-SH3 adapter protein NCK and the small GTPase RAC1, which both have been implicated in regulating cytoskeleton organization and axonal growth. Hypomorphic kette mutations lead to axonal defects similar to mutations in the Drosophila NCK homolog dreadlocks. Furthermore, we show that kette and dock mutants genetically interact. NCK is thought to interact with the small G proteins RAC1 and CDC42, which play a role in axonal growth. In line with these observations, a kette phenocopy can be obtained following directed expression of mutant DCDC42 or DRAC1 in the CNS midline. In addition, the kette mutant phenotype can be partially rescued by expression of an activated DRAC1 transgene. Our data suggest an important role of the HEM-2 protein in cytoskeletal organization during axonal pathfinding.
highroad Is a Carboxypetidase Induced by Retinoids to Clear Mutant Rhodopsin-1 in Drosophila Retinitis Pigmentosa Models

Directory of Open Access Journals (Sweden)

Huai-Wei Huang

2018-02-01

Full Text Available Rhodopsins require retinoid chromophores for their function. In vertebrates, retinoids also serve as signaling molecules, but whether these molecules similarly regulate gene expression in Drosophila remains unclear. Here, we report the identification of a retinoid-inducible gene in Drosophila, highroad, which is required for photoreceptors to clear folding-defective mutant Rhodopsin-1 proteins. Specifically, knockdown or genetic deletion of highroad blocks the degradation of folding-defective Rhodopsin-1 mutant, ninaEG69D. Moreover, loss of highroad accelerates the age-related retinal degeneration phenotype of ninaEG69D mutants. Elevated highroad transcript levels are detected in ninaEG69D flies, and interestingly, deprivation of retinoids in the fly diet blocks this effect. Consistently, mutations in the retinoid transporter, santa maria, impairs the induction of highroad in ninaEG69D flies. In cultured S2 cells, highroad expression is induced by retinoic acid treatment. These results indicate that cellular quality-control mechanisms against misfolded Rhodopsin-1 involve regulation of gene expression by retinoids.
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

. Whereas, 20% of Drosophila genes are annotated as encoding alternatively spliced premRNAs, splice-junction microarray experiments indicate that this number is at least 40% (ref. 7). Determining the diversity of mRNAs generated by alternative promoters, alternative splicing and RNA editing will substantially increase the inferred protein repertoire. Non-coding RNA genes (ncRNAs) including short interfering RNAs (siRNAs) and microRNAS (miRNAs) (reviewed in ref. 10), and longer ncRNAs such as bxd (ref. 11) and rox (ref. 12), have important roles in gene regulation, whereas others such as small nucleolar RNAs (snoRNAs)and small nuclear RNAs (snRNAs) are important components of macromolecular machines such as the ribosome and spliceosome. The transcription and processing of these ncRNAs must also be fully documented and mapped. As part of the modENCODE project to annotate the functional elements of the D. melanogaster and Caenorhabditis elegans genomes, we used RNA-Seq and tiling microarrays to sample the Drosophila transcriptome at unprecedented depth throughout development from early embryo to ageing male and female adults. We report on a high-resolution view of the discovery, structure and dynamic expression of the D. melanogaster transcriptome.
Analysis of the interaction between human RITA and Drosophila Suppressor of Hairless.

Science.gov (United States)

Brockmann, Birgit; Mastel, Helena; Oswald, Franz; Maier, Dieter

2014-12-01

Notch signalling mediates intercellular communication, which is effected by the transcription factor CSL, an acronym for vertebrate CBF1/RBP-J, Drosophila Suppressor of Hairless [Su(H)] and C. elegans Lag1. Nuclear import of CBF1/RBP-J depends on co-activators and co-repressors, whereas the export relies on RITA. RITA is a tubulin and CBF1/RBP-J binding protein acting as a negative regulator of Notch signalling in vertebrates. RITA protein is highly conserved in eumatazoa, but no Drosophila homologue was yet identified. In this work, the activity of human RITA in the fly was addressed. To this end, we generated transgenic flies that allow a tissue specific induction of human RITA, which was demonstrated by Western blotting and in fly tissues. Unexpectedly, overexpression of RITA during fly development had little phenotypic consequences, even when overexpressed simultaneously with either Su(H) or the Notch antagonist Hairless. We demonstrate the in vivo binding of human RITA to Su(H) and to tubulin by co-immune precipitation. Moreover, RITA and tubulin co-localized to some degree in several Drosophila tissues. Overall our data show that human RITA, albeit binding to Drosophila Su(H) and tubulin, cannot influence the Notch signalling pathway in the fly, suggesting that a nuclear export mechanism of Su(H), if existent in Drosophila, does not depend on RITA. © 2015 The Authors.
Differential effects of phytotherapic preparations in the hSOD1 Drosophila melanogaster model of ALS

Science.gov (United States)

De Rose, Francescaelena; Marotta, Roberto; Talani, Giuseppe; Catelani, Tiziano; Solari, Paolo; Poddighe, Simone; Borghero, Giuseppe; Marrosu, Francesco; Sanna, Enrico; Kasture, Sanjay; Acquas, Elio; Liscia, Anna

2017-01-01

The present study was aimed at characterizing the effects of Withania somnifera (Wse) and Mucuna pruriens (Mpe) on a Drosophila melanogaster model for Amyotrophic Lateral Sclerosis (ALS). In particular, the effects of Wse and Mpe were assessed following feeding the flies selectively overexpressing the wild human copper, zinc-superoxide dismutase (hSOD1-gain-of-function) in Drosophila motoneurons. Although ALS-hSOD1 mutants showed no impairment in life span, with respect to GAL4 controls, the results revealed impairment of climbing behaviour, muscle electrophysiological parameters (latency and amplitude of ePSPs) as well as thoracic ganglia mitochondrial functions. Interestingly, Wse treatment significantly increased lifespan of hSDO1 while Mpe had not effect. Conversely, both Wse and Mpe significantly rescued climbing impairment, and also latency and amplitude of ePSPs as well as failure responses to high frequency DLM stimulation. Finally, mitochondrial alterations were any more present in Wse- but not in Mpe-treated hSOD1 mutants. Hence, given the role of inflammation in the development of ALS, the high translational impact of the model, the known anti-inflammatory properties of these extracts, and the viability of their clinical use, these results suggest that the application of Wse and Mpe might represent a valuable pharmacological strategy to counteract the progression of ALS and related symptoms. PMID:28102336
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.
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.
Metabolome analysis of Drosophila melanogaster during embryogenesis.

Science.gov (United States)

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos' metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo.
Lethals induced by γ-radiation in drosophila somatic cells

International Nuclear Information System (INIS)

Ivanov, A.I.

1989-01-01

Exposure of 3-hour drosophila male embryos to γ-radiation during the topographic segregation of the germ anlage nuclei caused recessive sex-linked lethals in somatic cells only. The selectivity of the screening was determined by the ratio of mutation frequencies induced in embryos and adult males. Analysis of lethal mutations shows that a minimal rate of the divergence between germinal and somatic patterns of the cell development is observed in the embryogenesis, the 3d instar larva and prepupa, and maximal in the 1st and 2nd larva and pupa

Effects of curcuminoids identified in rhizomes of Curcuma longa on BACE-1 inhibitory and behavioral activity and lifespan of Alzheimer’s disease Drosophila models

Science.gov (United States)

2014-01-01

Background Alzheimer’s disease (AD) is the most common type of presenile and senile dementia. The human β-amyloid precursor cleavage enzyme (BACE-1) is a key enzyme responsible for amyloid plaque production, which implicates the progress and symptoms of AD. Here we assessed the anti-BACE-1 and behavioral activities of curcuminoids from rhizomes of Curcuma longa (Zingiberaceae), diarylalkyls curcumin (CCN), demethoxycurcumin (DMCCN), and bisdemethoxycurcumin (BDMCCN) against AD Drosophila melanogaster models. Methods Neuro-protective ability of the curcuminoids was assessed using Drosophila melanogaster model system overexpressing BACE-1 and its substrate APP in compound eyes and entire neurons. Feeding and climbing activity, lifespan, and morphostructural changes in fly eyes also were evaluated. Results BDMCCN has the strongest inhibitory activity toward BACE-1 with 17 μM IC50, which was 20 and 13 times lower than those of CCN and DMCCN respectively. Overexpression of APP/BACE-1 resulted in the progressive and measurable defects in morphology of eyes and locomotion. Remarkably, supplementing diet with either 1 mM BDMCCN or 1 mM CCN rescued APP/BACE1-expressing flies and kept them from developing both morphological and behavioral defects. Our results suggest that structural characteristics, such as degrees of saturation, types of carbon skeleton and functional group, and hydrophobicity appear to play a role in determining inhibitory potency of curcuminoids on BACE-1. Conclusion Further studies will warrant possible applications of curcuminoids as therapeutic BACE-1 blockers. PMID:24597901
Optogenetic pacing in Drosophila melanogaster

Science.gov (United States)

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

2015-01-01

Electrical stimulation is currently the gold standard for cardiac pacing. However, it is invasive and nonspecific for cardiac tissues. We recently developed a noninvasive cardiac pacing technique using optogenetic tools, which are widely used in neuroscience. Optogenetic pacing of the heart provides high spatial and temporal precisions, is specific for cardiac tissues, avoids artifacts associated with electrical stimulation, and therefore promises to be a powerful tool in basic cardiac research. We demonstrated optogenetic control of heart rhythm in a well-established model organism, Drosophila melanogaster. We developed transgenic flies expressing a light-gated cation channel, channelrhodopsin-2 (ChR2), specifically in their hearts and demonstrated successful optogenetic pacing of ChR2-expressing Drosophila at different developmental stages, including the larva, pupa, and adult stages. A high-speed and ultrahigh-resolution optical coherence microscopy imaging system that is capable of providing images at a rate of 130 frames/s with axial and transverse resolutions of 1.5 and 3.9 μm, respectively, was used to noninvasively monitor Drosophila cardiac function and its response to pacing stimulation. The development of a noninvasive integrated optical pacing and imaging system provides a novel platform for performing research studies in developmental cardiology. PMID:26601299
Xbp1-Independent Ire1 Signaling Is Required for Photoreceptor Differentiation and Rhabdomere Morphogenesis in Drosophila

Directory of Open Access Journals (Sweden)

Dina S. Coelho

2013-11-01

Full Text Available The unfolded protein response (UPR is composed by homeostatic signaling pathways that are activated by excessive protein misfolding in the endoplasmic reticulum. Ire1 signaling is an important mediator of the UPR, leading to the activation of the transcription factor Xbp1. Here, we show that Drosophila Ire1 mutant photoreceptors have defects in the delivery of rhodopsin-1 to the rhabdomere and in the secretion of Spacemaker/Eyes Shut into the interrhabdomeral space. However, these defects are not observed in Xbp1 mutant photoreceptors. Ire1 mutant retinas have higher mRNA levels for targets of regulated Ire1-dependent decay (RIDD, including for the fatty acid transport protein (fatp. Importantly, the downregulation of fatp by RNAi rescues the rhodopsin-1 delivery defects observed in Ire1 mutant photoreceptors. Our results show that the role of Ire1 during photoreceptor differentiation is independent of Xbp1 function and demonstrate the physiological relevance of the RIDD mechanism in this specific paradigm.
P element excision in drosophila melanogaster and related drosophilids

Science.gov (United States)

The frequency of P element excision and the structure of the resulting excision products were determined in three drosophilid species, Drosophila melanogaster, D. virilis, and Chymomyza procnemis. A transient P element mobility assay was conducted in the cells of developing insect embryos, but unlik...
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%. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
The Reproducibility of Indoor Air Pollution (IAP Measurement: A Test Case for the Measurement of Key Air Pollutants from the Pan Frying of Fish Samples

Directory of Open Access Journals (Sweden)

Ki-Hyun Kim

2014-01-01

Full Text Available To assess the robustness of various indoor air quality (IAQ indices, we explored the possible role of reproducibility-induced variability in the measurements of different pollutants under similar sampling and emissions conditions. Polluted indoor conditions were generated by pan frying fish samples in a closed room. A total of 11 experiments were carried out to measure a list of key variables commonly used to represent indoor air pollution (IAP indicators such as particulate matter (PM: PM1, PM2.5, PM10, and TSP and a set of individual volatile organic compounds (VOCs with some odor markers. The cooking activity conducted as part of our experiments was successful to consistently generate significant pollution levels (mean PM10: 7110 μg m−3 and mean total VOC (TVOC: 1400 μg m−3, resp.. Then, relative standard error (RSE was computed to assess the reproducibility between different IAP paramters measured across the repeated experiments. If the results were evaluated by an arbitrary criterion of 10%, the patterns were divided into two data groups (e.g., 10% for the remainders. Most noticeably, TVOC had the most repeatable results with a reproducibility (RSE value of 3.2% (n=11.
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
The sex of specific neurons controls female body growth in Drosophila.

Science.gov (United States)

Sawala, Annick; Gould, Alex P

2017-10-01

Sexual dimorphisms in body size are widespread throughout the animal kingdom but their underlying mechanisms are not well characterized. Most models for how sex chromosome genes specify size dimorphism have emphasized the importance of gonadal hormones and cell-autonomous influences in mammals versus strictly cell-autonomous mechanisms in Drosophila melanogaster. Here, we use tissue-specific genetics to investigate how sexual size dimorphism (SSD) is established in Drosophila. We find that the larger body size characteristic of Drosophila females is established very early in larval development via an increase in the growth rate per unit of body mass. We demonstrate that the female sex determination gene, Sex-lethal (Sxl), functions in central nervous system (CNS) neurons as part of a relay that specifies the early sex-specific growth trajectories of larval but not imaginal tissues. Neuronal Sxl acts additively in 2 neuronal subpopulations, one of which corresponds to 7 median neurosecretory cells: the insulin-producing cells (IPCs). Surprisingly, however, male-female differences in the production of insulin-like peptides (Ilps) from the IPCs do not appear to be involved in establishing SSD in early larvae, although they may play a later role. These findings support a relay model in which Sxl in neurons and Sxl in local tissues act together to specify the female-specific growth of the larval body. They also reveal that, even though the sex determination pathways in Drosophila and mammals are different, they both modulate body growth via a combination of tissue-autonomous and nonautonomous inputs.
Neuronal Cbl Controls Biosynthesis of Insulin-Like Peptides in Drosophila melanogaster

Science.gov (United States)

Yu, Yue; Sun, Ying; He, Shengqi; Yan, Cheng; Rui, Liangyou; Li, Wenjun

2012-01-01

The Cbl family proteins function as both E3 ubiquitin ligases and adaptor proteins to regulate various cellular signaling events, including the insulin/insulin-like growth factor 1 (IGF1) and epidermal growth factor (EGF) pathways. These pathways play essential roles in growth, development, metabolism, and survival. Here we show that in Drosophila melanogaster, Drosophila Cbl (dCbl) regulates longevity and carbohydrate metabolism through downregulating the production of Drosophila insulin-like peptides (dILPs) in the brain. We found that dCbl was highly expressed in the brain and knockdown of the expression of dCbl specifically in neurons by RNA interference increased sensitivity to oxidative stress or starvation, decreased carbohydrate levels, and shortened life span. Insulin-producing neuron-specific knockdown of dCbl resulted in similar phenotypes. dCbl deficiency in either the brain or insulin-producing cells upregulated the expression of dilp genes, resulting in elevated activation of the dILP pathway, including phosphorylation of Drosophila Akt and Drosophila extracellular signal-regulated kinase (dERK). Genetic interaction analyses revealed that blocking Drosophila epidermal growth factor receptor (dEGFR)-dERK signaling in pan-neurons or insulin-producing cells by overexpressing a dominant-negative form of dEGFR abolished the effect of dCbl deficiency on the upregulation of dilp genes. Furthermore, knockdown of c-Cbl in INS-1 cells, a rat β-cell line, also increased insulin biosynthesis and glucose-stimulated secretion in an ERK-dependent manner. Collectively, these results suggest that neuronal dCbl regulates life span, stress responses, and metabolism by suppressing dILP production and the EGFR-ERK pathway mediates the dCbl action. Cbl suppression of insulin biosynthesis is evolutionarily conserved, raising the possibility that Cbl may similarly exert its physiological actions through regulating insulin production in β cells. PMID:22778134
High rate of translocation-based gene birth on the Drosophila Y chromosome.

Science.gov (United States)

Tobler, Ray; Nolte, Viola; Schlötterer, Christian

2017-10-31

The Y chromosome is a unique genetic environment defined by a lack of recombination and male-limited inheritance. The Drosophila Y chromosome has been gradually acquiring genes from the rest of the genome, with only seven Y-linked genes being gained over the past 63 million years (0.12 gene gains per million years). Using a next-generation sequencing (NGS)-powered genomic scan, we show that gene transfers to the Y chromosome are much more common than previously suspected: at least 25 have arisen across three Drosophila species over the past 5.4 million years (1.67 per million years for each lineage). The gene transfer rate is significantly lower in Drosophila melanogaster than in the Drosophila simulans clade, primarily due to Y-linked retrotranspositions being significantly more common in the latter. Despite all Y-linked gene transfers being evolutionarily recent (Drosophila Y chromosome to be more dynamic than previously appreciated. Our analytical method provides a powerful means to identify Y-linked gene transfers and will help illuminate the evolutionary dynamics of the Y chromosome in Drosophila and other species. Copyright © 2017 the Author(s). Published by PNAS.
Genomic Signatures of Speciation in Sympatric and Allopatric Hawaiian Picture-Winged Drosophila.

Science.gov (United States)

Kang, Lin; Settlage, Robert; McMahon, Wyatt; Michalak, Katarzyna; Tae, Hongseok; Garner, Harold R; Stacy, Elizabeth A; Price, Donald K; Michalak, Pawel

2016-05-30

The Hawaiian archipelago provides a natural arena for understanding adaptive radiation and speciation. The Hawaiian Drosophila are one of the most diverse endemic groups in Hawaiì with up to 1,000 species. We sequenced and analyzed entire genomes of recently diverged species of Hawaiian picture-winged Drosophila, Drosophila silvestris and Drosophila heteroneura from Hawaiì Island, in comparison with Drosophila planitibia, their sister species from Maui, a neighboring island where a common ancestor of all three had likely occurred. Genome-wide single nucleotide polymorphism patterns suggest the more recent origin of D. silvestris and D. heteroneura, as well as a pervasive influence of positive selection on divergence of the three species, with the signatures of positive selection more prominent in sympatry than allopatry. Positively selected genes were significantly enriched for functional terms related to sensory detection and mating, suggesting that sexual selection played an important role in speciation of these species. In particular, sequence variation in Olfactory receptor and Gustatory receptor genes seems to play a major role in adaptive radiation in Hawaiian pictured-winged Drosophila. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
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.
New record for the invasive Spotted Wing Drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Anillaco, Argentina

Science.gov (United States)

The invasive Spotted Wing Drosophila (SWD), Drosophila suzukii Matsumura, is reported for the first time in La Rioja, Argentina. This represents a major range expansion for this species. The natural enemies of SWD, Leptopilina clavipes and Ganaspis hookeri were also collected with the SWD at the s...
Drosophila atonal fully rescues the phenotype of Math1 null mice: new functions evolve in new cellular contexts

Science.gov (United States)

Wang, Vincent Y.; Hassan, Bassem A.; Bellen, Hugo J.; Zoghbi, Huda Y.

2002-01-01

Many genes share sequence similarity between species, but their properties often change significantly during evolution. For example, the Drosophila genes engrailed and orthodenticle and the onychophoran gene Ultrabithorax only partially substitute for their mouse or Drosophila homologs. We have been analyzing the relationship between atonal (ato) in the fruit fly and its mouse homolog, Math1. In flies, ato acts as a proneural gene that governs the development of chordotonal organs (CHOs), which serve as stretch receptors in the body wall and joints and as auditory organs in the antennae. In the fly CNS, ato is important not for specification but for axonal arborization. Math1, in contrast, is required for the specification of cells in both the CNS and the PNS. Furthermore, Math1 serves a role in the development of secretory lineage cells in the gut, a function that does not parallel any known to be served by ato. We wondered whether ato and Math1 might be more functionally homologous than they appear, so we expressed Math1 in ato mutant flies and ato in Math1 null mice. To our surprise, the two proteins are functionally interchangeable.
Rasputin functions as a positive regulator of orb in Drosophila oogenesis.

Directory of Open Access Journals (Sweden)

Alexandre Costa

Full Text Available The determination of cell fate and the establishment of polarity axes during Drosophila oogenesis depend upon pathways that localize mRNAs within the egg chamber and control their on-site translation. One factor that plays a central role in regulating on-site translation of mRNAs is Orb. Orb is a founding member of the conserved CPEB family of RNA-binding proteins. These proteins bind to target sequences in 3' UTRs and regulate mRNA translation by modulating poly(A tail length. In addition to controlling the translation of axis-determining mRNAs like grk, fs(1K10, and osk, Orb protein autoregulates its own synthesis by binding to orb mRNA and activating its translation. We have previously shown that Rasputin (Rin, the Drosophila homologue of Ras-GAP SH3 Binding Protein (G3BP, associates with Orb in a messenger ribonucleoprotein (mRNP complex. Rin is an evolutionarily conserved RNA-binding protein believed to function as a link between Ras signaling and RNA metabolism. Here we show that Orb and Rin form a complex in the female germline. Characterization of a new rin allele shows that rin is essential for oogenesis. Co-localization studies suggest that Orb and Rin form a complex in the oocyte at different stages of oogenesis. This is supported by genetic and biochemical analyses showing that rin functions as a positive regulator in the orb autoregulatory pathway by increasing Orb protein expression. Tandem Mass Spectrometry analysis shows that several canonical stress granule proteins are associated with the Orb-Rin complex suggesting that a conserved mRNP complex regulates localized translation during oogenesis in Drosophila.
Rasputin functions as a positive regulator of orb in Drosophila oogenesis.

Science.gov (United States)

Costa, Alexandre; Pazman, Cecilia; Sinsimer, Kristina S; Wong, Li Chin; McLeod, Ian; Yates, John; Haynes, Susan; Schedl, Paul

2013-01-01

The determination of cell fate and the establishment of polarity axes during Drosophila oogenesis depend upon pathways that localize mRNAs within the egg chamber and control their on-site translation. One factor that plays a central role in regulating on-site translation of mRNAs is Orb. Orb is a founding member of the conserved CPEB family of RNA-binding proteins. These proteins bind to target sequences in 3' UTRs and regulate mRNA translation by modulating poly(A) tail length. In addition to controlling the translation of axis-determining mRNAs like grk, fs(1)K10, and osk, Orb protein autoregulates its own synthesis by binding to orb mRNA and activating its translation. We have previously shown that Rasputin (Rin), the Drosophila homologue of Ras-GAP SH3 Binding Protein (G3BP), associates with Orb in a messenger ribonucleoprotein (mRNP) complex. Rin is an evolutionarily conserved RNA-binding protein believed to function as a link between Ras signaling and RNA metabolism. Here we show that Orb and Rin form a complex in the female germline. Characterization of a new rin allele shows that rin is essential for oogenesis. Co-localization studies suggest that Orb and Rin form a complex in the oocyte at different stages of oogenesis. This is supported by genetic and biochemical analyses showing that rin functions as a positive regulator in the orb autoregulatory pathway by increasing Orb protein expression. Tandem Mass Spectrometry analysis shows that several canonical stress granule proteins are associated with the Orb-Rin complex suggesting that a conserved mRNP complex regulates localized translation during oogenesis in Drosophila.
Drosophila-Cdh1 (Rap/Fzr) a regulatory subunit of APC/C is required for synaptic morphology, synaptic transmission and locomotion.

Science.gov (United States)

Wise, Alexandria; Schatoff, Emma; Flores, Julian; Hua, Shao-Ying; Ueda, Atsushi; Wu, Chun-Fang; Venkatesh, Tadmiri

2013-11-01

The assembly of functional synapses requires the orchestration of the synthesis and degradation of a multitude of proteins. Protein degradation and modification by the conserved ubiquitination pathway has emerged as a key cellular regulatory mechanism during nervous system development and function (Kwabe and Brose, 2011). The anaphase promoting complex/cyclosome (APC/C) is a multi-subunit ubiquitin ligase complex primarily characterized for its role in the regulation of mitosis (Peters, 2002). In recent years, a role for APC/C in nervous system development and function has been rapidly emerging (Stegmuller and Bonni, 2005; Li et al., 2008). In the mammalian central nervous system the activator subunit, APC/C-Cdh1, has been shown to be a regulator of axon growth and dendrite morphogenesis (Konishi et al., 2004). In the Drosophila peripheral nervous system (PNS), APC2, a ligase subunit of the APC/C complex has been shown to regulate synaptic bouton size and activity (van Roessel et al., 2004). To investigate the role of APC/C-Cdh1 at the synapse we examined loss-of-function mutants of Rap/Fzr (Retina aberrant in pattern/Fizzy related), a Drosophila homolog of the mammalian Cdh1 during the development of the larval neuromuscular junction in Drosophila. Our cell biological, ultrastructural, electrophysiological, and behavioral data showed that rap/fzr loss-of-function mutations lead to changes in synaptic structure and function as well as locomotion defects. Data presented here show changes in size and morphology of synaptic boutons, and, muscle tissue organization. Electrophysiological experiments show that loss-of-function mutants exhibit increased frequency of spontaneous miniature synaptic potentials, indicating a higher rate of spontaneous synaptic vesicle fusion events. In addition, larval locomotion and peristaltic movement were also impaired. These findings suggest a role for Drosophila APC/C-Cdh1 mediated ubiquitination in regulating synaptic morphology
The Atg1-Tor pathway regulates yolk catabolism in Drosophila embryos.

Science.gov (United States)

Kuhn, Hallie; Sopko, Richelle; Coughlin, Margaret; Perrimon, Norbert; Mitchison, Tim

2015-11-15

Yolk provides an important source of nutrients during the early development of oviparous organisms. It is composed mainly of vitellogenin proteins packed into membrane-bound compartments called yolk platelets. Catabolism of yolk is initiated by acidification of the yolk platelet, leading to the activation of Cathepsin-like proteinases, but it is unknown how this process is triggered. Yolk catabolism initiates at cellularization in Drosophila melanogaster embryos. Using maternal shRNA technology we found that yolk catabolism depends on the Tor pathway and on the autophagy-initiating kinase Atg1. Whereas Atg1 was required for a burst of spatially regulated autophagy during late cellularization, autophagy was not required for initiating yolk catabolism. We propose that the conserved Tor metabolic sensing pathway regulates yolk catabolism, similar to Tor-dependent metabolic regulation on the lysosome. © 2015. Published by The Company of Biologists Ltd.
The spliceosome-associated protein Mfap1 binds to VCP in Drosophila.

Directory of Open Access Journals (Sweden)

Sandra Rode

Full Text Available Posttranscriptional regulation of gene expression contributes to many developmental transitions. Previously, we found that the AAA chaperone Valosin-Containing Protein (VCP regulates ecdysone-dependent dendrite pruning of Drosophila class IV dendritic arborization (c4da neurons via an effect on RNA metabolism. In a search for RNA binding proteins associated with VCP, we identified the spliceosome-associated protein Mfap1, a component of the tri-snRNP complex. Mfap1 is a nucleolar protein in neurons and its levels are regulated by VCP. Mfap1 binds to VCP and TDP-43, a disease-associated RNA-binding protein. via distinct regions in its N- and C-terminal halfs. Similar to vcp mutations, Mfap1 overexpression causes c4da neuron dendrite pruning defects and mislocalization of TDP-43 in these cells, but genetic analyses show that Mfap1 is not a crucial VCP target during dendrite pruning. Finally, rescue experiments with a lethal mfap1 mutant show that the VCP binding region is not essential for Mfap1 function, but may act to increase its stability or activity.
The Drosophila melanogaster circadian pacemaker circuit

Indian Academy of Sciences (India)

2016-08-26

Aug 26, 2016 ... Keywords. circadian rhythm; neuronal network; ion channel; behaviour; neurotransmitter; electrophysiology; Drosophila. Abstract. 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 ...

Chromosomal localization of microsatellite loci in Drosophila mediopunctata

Directory of Open Access Journals (Sweden)

Renato Cavasini

2015-03-01

Full Text Available Drosophila mediopunctata has been used as a model organism for genetics and evolutionary studies in the last three decades. A linkage map with 48 microsatellite loci recently published for this species showed five syntenic groups, which had their homology determined to Drosophila melanogaster chromosomes. Then, by inference, each of the groups was associated with one of the five major chromosomes of D. mediopunctata. Our objective was to carry out a genetic (chromosomal analysis to increase the number of available loci with known chromosomal location. We made a simultaneous analysis of visible mutant phenotypes and microsatellite genotypes in a backcross of a standard strain and a mutant strain, which had each major autosome marked. Hence, we could establish the chromosomal location of seventeen loci; including one from each of the five major linkage groups previously published, and twelve new loci. Our results were congruent with the previous location and they open new possibilities to future work integrating microsatellites, chromosomal inversions, and genetic determinants of physiological and morphological variation.
Loss of Drosophila i-AAA protease, dYME1L, causes abnormal mitochondria and apoptotic degeneration.

Science.gov (United States)

Qi, Y; Liu, H; Daniels, M P; Zhang, G; Xu, H

2016-02-01

Mitochondrial AAA (ATPases Associated with diverse cellular Activities) proteases i-AAA (intermembrane space-AAA) and m-AAA (matrix-AAA) are closely related and have major roles in inner membrane protein homeostasis. Mutations of m-AAA proteases are associated with neuromuscular disorders in humans. However, the role of i-AAA in metazoans is poorly understood. We generated a deletion affecting Drosophila i-AAA, dYME1L (dYME1L(del)). Mutant flies exhibited premature aging, progressive locomotor deficiency and neurodegeneration that resemble some key features of m-AAA diseases. dYME1L(del) flies displayed elevated mitochondrial unfolded protein stress and irregular cristae. Aged dYME1L(del) flies had reduced complex I (NADH/ubiquinone oxidoreductase) activity, increased level of reactive oxygen species (ROS), severely disorganized mitochondrial membranes and increased apoptosis. Furthermore, inhibiting apoptosis by targeting dOmi (Drosophila Htra2/Omi) or DIAP1, or reducing ROS accumulation suppressed retinal degeneration. Our results suggest that i-AAA is essential for removing unfolded proteins and maintaining mitochondrial membrane architecture. Loss of i-AAA leads to the accumulation of oxidative damage and progressive deterioration of membrane integrity, which might contribute to apoptosis upon the release of proapoptotic molecules such as dOmi. Containing ROS level could be a potential strategy to manage mitochondrial AAA protease deficiency.
Resting-State Functional MR Imaging for Determining Language Laterality in Intractable Epilepsy.

Science.gov (United States)

DeSalvo, Matthew N; Tanaka, Naoaki; Douw, Linda; Leveroni, Catherine L; Buchbinder, Bradley R; Greve, Douglas N; Stufflebeam, Steven M

2016-10-01

Purpose To measure the accuracy of resting-state functional magnetic resonance (MR) imaging in determining hemispheric language dominance in patients with medically intractable focal epilepsies against the results of an intracarotid amobarbital procedure (IAP). Materials and Methods This study was approved by the institutional review board, and all subjects gave signed informed consent. Data in 23 patients with medically intractable focal epilepsy were retrospectively analyzed. All 23 patients were candidates for epilepsy surgery and underwent both IAP and resting-state functional MR imaging as part of presurgical evaluation. Language dominance was determined from functional MR imaging data by calculating a laterality index (LI) after using independent component analysis. The accuracy of this method was assessed against that of IAP by using a variety of thresholds. Sensitivity and specificity were calculated by using leave-one-out cross validation. Spatial maps of language components were qualitatively compared among each hemispheric language dominance group. Results Measurement of hemispheric language dominance with resting-state functional MR imaging was highly concordant with IAP results, with up to 96% (22 of 23) accuracy, 96% (22 of 23) sensitivity, and 96% (22 of 23) specificity. Composite language component maps in patients with typical language laterality consistently included classic language areas such as the inferior frontal gyrus, the posterior superior temporal gyrus, and the inferior parietal lobule, while those of patients with atypical language laterality also included non-classical language areas such as the superior and middle frontal gyri, the insula, and the occipital cortex. Conclusion Resting-state functional MR imaging can be used to measure language laterality in patients with medically intractable focal epilepsy. (©) RSNA, 2016 Online supplemental material is available for this article.
Characterization of the Drosophila ortholog of the human Usher Syndrome type 1G protein sans.

Directory of Open Access Journals (Sweden)

Fabio Demontis

Full Text Available BACKGROUND: The Usher syndrome (USH is the most frequent deaf-blindness hereditary disease in humans. Deafness is attributed to the disorganization of stereocilia in the inner ear. USH1, the most severe subtype, is associated with mutations in genes encoding myosin VIIa, harmonin, cadherin 23, protocadherin 15, and sans. Myosin VIIa, harmonin, cadherin 23, and protocadherin 15 physically interact in vitro and localize to stereocilia tips in vivo, indicating that they form functional complexes. Sans, in contrast, localizes to vesicle-like structures beneath the apical membrane of stereocilia-displaying hair cells. How mutations in sans result in deafness and blindness is not well understood. Orthologs of myosin VIIa and protocadherin 15 have been identified in Drosophila melanogaster and their genetic analysis has identified essential roles in auditory perception and microvilli morphogenesis, respectively. PRINCIPAL FINDINGS: Here, we have identified and characterized the Drosophila ortholog of human sans. Drosophila Sans is expressed in tubular organs of the embryo, in lens-secreting cone cells of the adult eye, and in microvilli-displaying follicle cells during oogenesis. Sans mutants are viable, fertile, and mutant follicle cells appear to form microvilli, indicating that Sans is dispensable for fly development and microvilli morphogenesis in the follicle epithelium. In follicle cells, Sans protein localizes, similar to its vertebrate ortholog, to intracellular punctate structures, which we have identified as early endosomes associated with the syntaxin Avalanche. CONCLUSIONS: Our work is consistent with an evolutionary conserved function of Sans in vesicle trafficking. Furthermore it provides a significant basis for further understanding of the role of this Usher syndrome ortholog in development and disease.
Tradução, adaptação transcultural e evidências de validade da escala improvisation assessment profiles (IAPs) para uso no Brasil

DEFF Research Database (Denmark)

Gattino, Gustavo; Ferrari, Karina; Azevedo, Graciane

2016-01-01

This article is intended to present the second part of the research which created the Improvisation Assessment Profiles (IAPs) version in Brazil according to a formal translation process and the analysis of the instrument in relation to its cross-cultural adaptation. The scale was also evaluated ...
Phylogeny of the Genus Drosophila

Science.gov (United States)

O’Grady, Patrick M.; DeSalle, Rob

2018-01-01

Understanding phylogenetic relationships among taxa is key to designing and implementing comparative analyses. The genus Drosophila, which contains over 1600 species, is one of the most important model systems in the biological sciences. For over a century, one species in this group, Drosophila melanogaster, has been key to studies of animal development and genetics, genome organization and evolution, and human disease. As whole-genome sequencing becomes more cost-effective, there is increasing interest in other members of this morphologically, ecologically, and behaviorally diverse genus. Phylogenetic relationships within Drosophila are complicated, and the goal of this paper is to provide a review of the recent taxonomic changes and phylogenetic relationships in this genus to aid in further comparative studies. PMID:29716983
Expression of human PQBP-1 in Drosophila impairs long-term memory and induces abnormal courtship.

Science.gov (United States)

Yoshimura, Natsue; Horiuchi, Daisuke; Shibata, Masao; Saitoe, Minoru; Qi, Mei-Ling; Okazawa, Hitoshi

2006-04-17

Frame shift mutations of the polyglutamine binding protein-1 (PQBP1) gene lead to total or partial truncation of the C-terminal domain (CTD) and cause mental retardation in human patients. Interestingly, normal Drosophila homologue of PQBP-1 lacks CTD. As a model to analyze the molecular network of PQBP-1 affecting intelligence, we generated transgenic flies expressing human PQBP-1 with CTD. Pavlovian olfactory conditioning revealed that the transgenic flies showed disturbance of long-term memory. In addition, they showed abnormal courtship that male flies follow male flies. Abnormal functions of PQBP-1 or its binding partner might be linked to these symptoms.
Characterization of Autophagic Responses in Drosophila melanogaster.

Science.gov (United States)

Xu, T; Kumar, S; Denton, D

2017-01-01

Drosophila is an excellent model system for studying autophagy during animal development due to the availability of genetic reagents and opportunity for in vivo cell biological analysis. The regulation and mechanism of autophagy are highly evolutionarily conserved and the role of autophagy has been characterized during various stages of Drosophila development as well as following starvation. Studies in Drosophila have revealed novel insights into the role of distinct components of the autophagy machinery. This chapter describes protocols for examining autophagy during Drosophila development. A crucial step in the induction of autophagy is the incorporation of Atg8a into the autophagosome. This can be measured as autophagic puncta using live fluorescent imaging, immunostaining, or immunoblot analysis of LC3/Atg8a processing. The level of autophagy can also be examined using other specific components of the autophagy pathway as markers detected by immunofluorescent imaging. Based on the distinct morphology of autophagy, it can also be examined by transmission electron microscopy. In addition, one of the advantages of using Drosophila as a model is the ability to undertake genetic analysis of individual components of the autophagy machinery. Current approaches that can be used to monitor autophagy, including the overall flux and individual steps in Drosophila melanogaster, will be discussed. © 2017 Elsevier Inc. All rights reserved.
Recombining without Hotspots: A Comprehensive Evolutionary Portrait of Recombination in Two Closely Related Species of Drosophila

Science.gov (United States)

Smukowski Heil, Caiti S.; Ellison, Chris; Dubin, Matthew; Noor, Mohamed A.F.

2015-01-01

Meiotic recombination rate varies across the genome within and between individuals, populations, and species in virtually all taxa studied. In almost every species, this variation takes the form of discrete recombination hotspots, determined in some mammals by a protein called PRDM9. Hotspots and their determinants have a profound effect on the genomic landscape, and share certain features that extend across the tree of life. Drosophila, in contrast, are anomalous in their absence of hotspots, PRDM9, and other species-specific differences in the determination of recombination. To better understand the evolution of meiosis and general patterns of recombination across diverse taxa, we present a truly comprehensive portrait of recombination across time, combining recently published cross-based contemporary recombination estimates from each of two sister species with newly obtained linkage-disequilibrium-based historic estimates of recombination from both of these species. Using Drosophila pseudoobscura and Drosophila miranda as a model system, we compare recombination rate between species at multiple scales, and we suggest that Drosophila replicate the pattern seen in human–chimpanzee in which recombination rate is conserved at broad scales. We also find evidence of a species-wide recombination modifier(s), resulting in both a present and historic genome-wide elevation of recombination rates in D. miranda, and identify broad scale effects on recombination from the presence of an inversion. Finally, we reveal an unprecedented view of the distribution of recombination in D. pseudoobscura, illustrating patterns of linked selection and where recombination is taking place. Overall, by combining these estimation approaches, we highlight key similarities and differences in recombination between Drosophila and other organisms. PMID:26430062
Data for increase of Lymantria dispar male survival after topical application of single-stranded RING domain fragment of IAP-3 gene of its nuclear polyhedrosis virus

Science.gov (United States)

Oberemok, Volodymyr V.; Laikova, Kateryna V.; Zaitsev, Aleksei S.; Gushchin, Vladimir A.; Skorokhod, Oleksii A.

2016-01-01

This data article is related to the research article entitled “The RING for gypsy moth control: topical application of fragment of its nuclear polyhedrosis virus anti-apoptosis gene as insecticide” [1]. This article reports on significantly higher survival of gypsy moth Lymantria dispar male individuals in response to topical application of single-stranded DNA, based on RING (really interesting new gene) domain fragment of LdMNPV (L. dispar multicapsid nuclear polyhedrosis virus) IAP-3 (inhibitor of apoptosis) gene and acted as DNA insecticide. PMID:27054151
Determinants and Management Outcomes of Pelvic Organ Prolapse ...

African Journals Online (AJOL)

Conclusion: The incidence of pelvic organ prolapse in this study was 6.5% and the leading determinants of pelvic organ prolapse were multiparity, menopause, chronic increase in IAP and advanced age. Most were lost to follow-up and a lesser proportion was offered conservative management. Early presentation of women ...
Drosophila as a model to study the role of blood cells in inflammation, innate immunity and cancer

Science.gov (United States)

Wang, Lihui; Kounatidis, Ilias; Ligoxygakis, Petros

2014-01-01

Drosophila has a primitive yet effective blood system with three types of haemocytes which function throughout different developmental stages and environmental stimuli. Haemocytes play essential roles in tissue modeling during embryogenesis and morphogenesis, and also in innate immunity. The open circulatory system of Drosophila makes haemocytes ideal signal mediators to cells and tissues in response to events such as infection and wounding. The application of recently developed and sophisticated genetic tools to the relatively simple genome of Drosophila has made the fly a popular system for modeling human tumorigensis and metastasis. Drosophila is now used for screening and investigation of genes implicated in human leukemia and also in modeling development of solid tumors. This second line of research offers promising opportunities to determine the seemingly conflicting roles of blood cells in tumor progression and invasion. This review provides an overview of the signaling pathways conserved in Drosophila during haematopoiesis, haemostasis, innate immunity, wound healing and inflammation. We also review the most recent progress in the use of Drosophila as a cancer research model with an emphasis on the roles haemocytes can play in various cancer models and in the links between inflammation and cancer. PMID:24409421
Patterns of Nucleotide Diversity at the Regions Encompassing the Drosophila Insulin-Like Peptide (dilp) Genes: Demography vs. Positive Selection in Drosophila melanogaster

Science.gov (United States)

Guirao-Rico, Sara; Aguadé, Montserrat

2013-01-01

In Drosophila, the insulin-signaling pathway controls some life history traits, such as fertility and lifespan, and it is considered to be the main metabolic pathway involved in establishing adult body size. Several observations concerning variation in body size in the Drosophila genus are suggestive of its adaptive character. Genes encoding proteins in this pathway are, therefore, good candidates to have experienced adaptive changes and to reveal the footprint of positive selection. The Drosophila insulin-like peptides (DILPs) are the ligands that trigger the insulin-signaling cascade. In Drosophila melanogaster, there are several peptides that are structurally similar to the single mammalian insulin peptide. The footprint of recent adaptive changes on nucleotide variation can be unveiled through the analysis of polymorphism and divergence. With this aim, we have surveyed nucleotide sequence variation at the dilp1-7 genes in a natural population of D. melanogaster. The comparison of polymorphism in D. melanogaster and divergence from D. simulans at different functional classes of the dilp genes provided no evidence of adaptive protein evolution after the split of the D. melanogaster and D. simulans lineages. However, our survey of polymorphism at the dilp gene regions of D. melanogaster has provided some evidence for the action of positive selection at or near these genes. The regions encompassing the dilp1-4 genes and the dilp6 gene stand out as likely affected by recent adaptive events. PMID:23308258
Structure of PCNA from Drosophila melanogaster

International Nuclear Information System (INIS)

Wang, Ke; Shi, Zhubing; Zhang, Min; Cheng, Dianlin

2013-01-01

Proliferating cell nuclear antigen (PCNA) plays essential roles in DNA replication, DNA repair, cell-cycle regulation and chromatin metabolism. The PCNA from Drosophila melanogaster (DmPCNA) has been purified and crystallized. Proliferating cell nuclear antigen (PCNA) plays essential roles in DNA replication, DNA repair, cell-cycle regulation and chromatin metabolism. The PCNA from Drosophila melanogaster (DmPCNA) was purified and crystallized. The crystal of DmPCNA diffracted to 2.0 Å resolution and belonged to space group H3, with unit-cell parameters a = b = 151.16, c = 38.28 Å. The structure of DmPCNA was determined by molecular replacement. DmPCNA forms a symmetric homotrimer in a head-to-tail manner. An interdomain connector loop (IDCL) links the N- and C-terminal domains. Additionally, the N-terminal and C-terminal domains contact each other through hydrophobic associations. Compared with human PCNA, the IDCL of DmPCNA has conformational changes, which may explain their difference in function. This work provides a structural basis for further functional and evolutionary studies of PCNA
Clueless, a protein required for mitochondrial function, interacts with the PINK1-Parkin complex in Drosophila

Directory of Open Access Journals (Sweden)

Aditya Sen

2015-06-01

Full Text Available Loss of mitochondrial function often leads to neurodegeneration and is thought to be one of the underlying causes of neurodegenerative diseases such as Parkinson's disease (PD. However, the precise events linking mitochondrial dysfunction to neuronal death remain elusive. PTEN-induced putative kinase 1 (PINK1 and Parkin (Park, either of which, when mutated, are responsible for early-onset PD, mark individual mitochondria for destruction at the mitochondrial outer membrane. The specific molecular pathways that regulate signaling between the nucleus and mitochondria to sense mitochondrial dysfunction under normal physiological conditions are not well understood. Here, we show that Drosophila Clueless (Clu, a highly conserved protein required for normal mitochondrial function, can associate with Translocase of the outer membrane (TOM 20, Porin and PINK1, and is thus located at the mitochondrial outer membrane. Previously, we found that clu genetically interacts with park in Drosophila female germ cells. Here, we show that clu also genetically interacts with PINK1, and our epistasis analysis places clu downstream of PINK1 and upstream of park. In addition, Clu forms a complex with PINK1 and Park, further supporting that Clu links mitochondrial function with the PINK1-Park pathway. Lack of Clu causes PINK1 and Park to interact with each other, and clu mutants have decreased mitochondrial protein levels, suggesting that Clu can act as a negative regulator of the PINK1-Park pathway. Taken together, these results suggest that Clu directly modulates mitochondrial function, and that Clu's function contributes to the PINK1-Park pathway of mitochondrial quality control.
Epigenetic telomere protection by Drosophila DNA damage response pathways.

Science.gov (United States)

Oikemus, Sarah R; Queiroz-Machado, Joana; Lai, KuanJu; McGinnis, Nadine; Sunkel, Claudio; Brodsky, Michael H

2006-05-01

Analysis of terminal deletion chromosomes indicates that a sequence-independent mechanism regulates protection of Drosophila telomeres. Mutations in Drosophila DNA damage response genes such as atm/tefu, mre11, or rad50 disrupt telomere protection and localization of the telomere-associated proteins HP1 and HOAP, suggesting that recognition of chromosome ends contributes to telomere protection. However, the partial telomere protection phenotype of these mutations limits the ability to test if they act in the epigenetic telomere protection mechanism. We examined the roles of the Drosophila atm and atr-atrip DNA damage response pathways and the nbs homolog in DNA damage responses and telomere protection. As in other organisms, the atm and atr-atrip pathways act in parallel to promote telomere protection. Cells lacking both pathways exhibit severe defects in telomere protection and fail to localize the protection protein HOAP to telomeres. Drosophila nbs is required for both atm- and atr-dependent DNA damage responses and acts in these pathways during DNA repair. The telomere fusion phenotype of nbs is consistent with defects in each of these activities. Cells defective in both the atm and atr pathways were used to examine if DNA damage response pathways regulate telomere protection without affecting telomere specific sequences. In these cells, chromosome fusion sites retain telomere-specific sequences, demonstrating that loss of these sequences is not responsible for loss of protection. Furthermore, terminally deleted chromosomes also fuse in these cells, directly implicating DNA damage response pathways in the epigenetic protection of telomeres. We propose that recognition of chromosome ends and recruitment of HP1 and HOAP by DNA damage response proteins is essential for the epigenetic protection of Drosophila telomeres. Given the conserved roles of DNA damage response proteins in telomere function, related mechanisms may act at the telomeres of other organisms.
Analysis of Thioester-Containing Proteins during the Innate Immune Response of Drosophila melanogaster

Science.gov (United States)

Bou Aoun, Richard; Hetru, Charles; Troxler, Laurent; Doucet, Daniel; Ferrandon, Dominique; Matt, Nicolas

2010-01-01

Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1–Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila. PMID:21063077
Intestinal stem cells in the adult Drosophila midgut

International Nuclear Information System (INIS)

Jiang, Huaqi; Edgar, Bruce A.

2011-01-01

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.
Drosophila larvae food intake cessation following exposure to Erwinia contaminated media requires odor perception, Trpa1 channel and evf virulence factor.

Science.gov (United States)

Keita, Seydou; Masuzzo, Ambra; Royet, Julien; Kurz, C Leopold

2017-05-01

When exposed to microorganisms, animals use several protective strategies. On one hand, as elegantly exemplified in Drosophila melanogaster, the innate immune system recognizes microbial compounds and triggers an antimicrobial response. On the other hand, behaviors preventing an extensive contact with the microbes and thus reducing the risk of infection have been described. However, these reactions ranging from microbes aversion to intestinal transit increase or food intake decrease have been rarely defined at the molecular level. In this study, we set up an experimental system that allowed us to rapidly identify and quantify food intake decreases in Drosophila larvae exposed to media contaminated with bacteria. Specifically, we report a robust dose-dependent food intake decrease following exposure to the bacteria Erwinia carotovora carotovora strain Ecc15. We demonstrate that this response does not require Imd innate immune pathway, but rather the olfactory neuronal circuitry, the Trpa1 receptor and the evf virulence factor. Finally, we show that Ecc15 induce the same behavior in the invasive pest insect Drosophila suzukii. Copyright © 2017 Elsevier Ltd. All rights reserved.
Toll-8/Tollo negatively regulates antimicrobial response in the Drosophila respiratory epithelium.

Directory of Open Access Journals (Sweden)

Idir Akhouayri

2011-10-01

Full Text Available Barrier epithelia that are persistently exposed to microbes have evolved potent immune tools to eliminate such pathogens. If mechanisms that control Drosophila systemic responses are well-characterized, the epithelial immune responses remain poorly understood. Here, we performed a genetic dissection of the cascades activated during the immune response of the Drosophila airway epithelium i.e. trachea. We present evidence that bacteria induced-antimicrobial peptide (AMP production in the trachea is controlled by two signalling cascades. AMP gene transcription is activated by the inducible IMD pathway that acts non-cell autonomously in trachea. This IMD-dependent AMP activation is antagonized by a constitutively active signalling module involving the receptor Toll-8/Tollo, the ligand Spätzle2/DNT1 and Ect-4, the Drosophila ortholog of the human Sterile alpha and HEAT/ARMadillo motif (SARM. Our data show that, in addition to Toll-1 whose function is essential during the systemic immune response, Drosophila relies on another Toll family member to control the immune response in the respiratory epithelium.

Strong dietary restrictions protect Drosophila against anoxia/reoxygenation injuries.

Directory of Open Access Journals (Sweden)

Paul Vigne

Full Text Available Reoxygenation of ischemic tissues is a major factor that determines the severity of cardiovascular diseases. This paper describes the consequences of anoxia/reoxygenation (A/R stresses on Drosophila, a useful, anoxia tolerant, model organism.Newly emerged adult male flies were exposed to anoxic conditions (<1% O2 for 1 to 6 hours, reoxygenated and their survival was monitored.A/R stresses induced a transient increase in mortality which peaked at the time of reoxygenation. Then flies recovered low mortality rates similar to those of control flies. A/R induced mortality was strongly dependent on dietary conditions during the 48 h that preceded anoxia. Well fed flies were anoxia sensitive. Strong dietary restrictions and starvation conditions protected flies against A/R injuries. The tolerance to anoxia was associated to large decreases in glycogen, protein, and ATP contents. During anoxia, anoxia tolerant flies produced more lactate, less phosphate and they maintained more stable ATP levels than anoxia sensitive flies. Moderate dietary restrictions, which increased the longevity of normoxic flies, did not promote resistance to A/R stresses. Diet dependent A/R injuries were still observed in sigma loss of function mutants and they were insensitive to dietary rapamycin or resveratrol. AICAR (5-aminoimidazole-4-carboxamide-1-beta-D-ribose-furanoside, an activator AMP kinase decreased A/R injuries. Mutants in the insulin signalling pathway were more anoxia tolerant in a fed state.Long A/R stresses induce a transient increase in mortality in Drosophila. This mortality is highly dependent on dietary conditions prior to the stress. Strong dietary restrictions and starvation conditions protect flies against A/R injuries, probably by inducing a major remodelling of energy metabolism. The results also indicate that mechanistically different responses develop in response to dietary restrictions of different strengths. AMP kinase and the insulin signalling
Interorgan Communication Pathways in Physiology: Focus on Drosophila

OpenAIRE

Droujinine, Ilia A.; Perrimon, Norbert

2016-01-01

Studies in mammals and Drosophila have demonstrated the existence and significance of secreted factors involved in communication between distal organs. In this review, primarily focusing on Drosophila, we examine the known interorgan communication factors and their functions, physiological inducers, and integration in regulating physiology. Moreover, we describe how organ-sensing screens in Drosophila can systematically identify novel conserved interorgan communication factors. Finally, we di...
Gene expression variations during Drosophila metamorphosis in space: The GENE experiment in the Spanish cervantes missions to the ISS

Science.gov (United States)

Herranz, Raul; Benguria, Alberto; Medina, Javier; Gasset, Gilbert; van Loon, Jack J.; Zaballos, Angel; Marco, Roberto

2005-08-01

The ISS expedition 8, a Soyuz Mission, flew to the International Space Station (ISS) to replace the two- member ISS crew during October 2003. During this crew exchanging flight, the Spanish Cervantes Scientific Mission took place. In it some biological experiments were performed among them three proposed by our Team. The third member of the expedition, the Spanish born ESA astronaut Pedro Duque, returned within the Soyuz 7 capsule carrying the experiment containing transport box after almost 11 days in microgravity. In one of the three experiments, the GENE experiment, we intended to determine how microgravity affects the gene expression pattern of Drosophila with one of the current more powerful technologies , a complete Drosophila melanogaster genome microarray (AffymetrixTM, version 1.0). Due to the constrains in the current ISS experiments, we decided to limit our experiment to the organism rebuilding processes that occurs during Drosophila metamorphosis. In addition to the ISS samples, several control experiments have been performed including a 1g Ground control parallel to the ISS flight samples, a Random Position Machine microgravity simulated control and a parallel Hypergravity (10g) experiment. Extracted RNA from the samples was used to test the differences in gene expression during Drosophila development. A preliminary analysis of the results indicates that around five hundred genes change their expression profiles, many of them belonging to particular ontology classification groups.
Dumpy-30 family members as determinants of male fertility and interaction partners of metal-responsive transcription factor 1 (MTF-1 in Drosophila

Directory of Open Access Journals (Sweden)

Renkawitz-Pohl Renate

2008-06-01

Full Text Available Abstract Background Metal-responsive transcription factor 1 (MTF-1, which binds to metal response elements (MREs, plays a central role in transition metal detoxification and homeostasis. A Drosophila interactome analysis revealed two candidate dMTF-1 interactors, both of which are related to the small regulatory protein Dumpy-30 (Dpy-30 of the worm C. elegans. Dpy-30 is the founding member of a protein family involved in chromatin modifications, notably histone methylation. Mutants affect mating type in yeast and male mating in C. elegans. Results Constitutive expression of the stronger interactor, Dpy-30L1 (CG6444, in transgenic flies inhibits MTF-1 activity and results in elevated sensitivity to Cd(II and Zn(II, an effect that could be rescued by co-overexpression of dMTF-1. Electrophoretic mobility shift assays (EMSA suggest that Dpy-30L1 interferes with the binding of MTF-1 to its cognate MRE binding site. Dpy-30L1 is expressed in the larval brain, gonads, imaginal discs, salivary glands and in the brain, testes, ovaries and salivary glands of adult flies. Expression of the second interactor, Dpy-30L2 (CG11591, is restricted to larval male gonads, and to the testes of adult males. Consistent with these findings, dpy-30-like transcripts are also prominently expressed in mouse testes. Targeted gene disruption by homologous recombination revealed that dpy-30L1 knockout flies are viable and show no overt disruption of metal homeostasis. In contrast, the knockout of the male-specific dpy-30L2 gene results in male sterility, as does the double knockout of dpy-30L1 and dpy-30L2. A closer inspection showed that Dpy-30L2 is expressed in elongated spermatids but not in early or mature sperm. Mutant sperm had impaired motility and failed to accumulate in sperm storage organs of females. Conclusion Our studies help to elucidate the physiological roles of the Dumpy-30 proteins, which are conserved from yeast to humans and typically act in concert with
Radioresistance and radiosensitivity in Drosophila melanogaster

International Nuclear Information System (INIS)

Reguly, M.L.; Marques, E.K.

1987-01-01

The mechanisms of radioresistance in Drosophila are studied. The mutagenic effects of 5KR of 60 Cobalt gamma radiation and of 0,006M dose of ethyl methanesulfonate (EMS) on four D. Melanogaster strains (RC 1 , CO 3 , BUE and LEN) are investigated. (M.A.C.) [pt
The Drosophila nerfin-1 mRNA requires multiple microRNAs to regulate its spatial and temporal translation dynamics in the developing nervous system.

Science.gov (United States)

Kuzin, Alexander; Kundu, Mukta; Brody, Thomas; Odenwald, Ward F

2007-10-01

The mRNA encoding the Drosophila Zn-finger transcription factor Nerfin-1, required for CNS axon pathfinding events, is subject to post-transcriptional silencing. Although nerfin-1 mRNA is expressed in many neural precursor cells including all early delaminating CNS neuroblasts, the encoded Nerfin-1 protein is detected only in the nuclei of neural precursors that divide just once to generate neurons and then only transiently in nascent neurons. Using a nerfin-1 promoter-controlled reporter transgene, replacement of the nerfin-1 3' UTR with the viral SV-40 3' UTR releases the neuroblast translational block and prolongs reporter protein expression in neurons. Comparative genomics analysis reveals that the nerfin-1 mRNA 3' UTR contains multiple highly conserved sequence blocks that either harbor and/or overlap 21 predicted binding sites for 18 different microRNAs. To determine the functional significance of these microRNA-binding sites and less conserved microRNA target sites, we have studied their ability to block or limit the expression of reporter protein in nerfin-1-expressing cells during embryonic development. Our results indicate that no single microRNA is sufficient to fully inhibit protein expression but rather multiple microRNAs that target different binding sites are required to block ectopic protein expression in neural precursor cells and temporally restrict expression in neurons. Taken together, these results suggest that multiple microRNAs play a cooperative role in the post-transcriptional regulation of nerfin-1 mRNA, and the high degree of microRNA-binding site evolutionary conservation indicates that all members of the Drosophila genus employ a similar strategy to regulate the onset and extinction dynamics of Nerfin-1 expression.
Enteral intestinal alkaline phosphatase administration in newborns decreases iNOS expression in a neonatal necrotizing enterocolitis rat model.

Science.gov (United States)

Rentea, Rebecca M; Liedel, Jennifer L; Fredrich, Katherine; Pritchard, Kirkwood; Oldham, Keith T; Simpson, Pippa M; Gourlay, David M

2013-01-01

To determine if intestinal alkaline phosphatase (IAP) decreases intestinal injury resulting from experimentally induced necrotizing enterocolitis (NEC). We hypothesized that IAP administration prevents the initial development of NEC related intestinal inflammation. Pre- and full-term newborn Sprague-Dawley rat pups were sacrificed on day 1 of life. Pre-term pups were exposed to intermittent hypoxia and formula containing LPS to induce NEC. Select NEC pups were given 40, 4 or 0.4 units/kg of bovine IAP (NEC+IAP40u, IAP4u or IAP0.4u) enterally, once daily. Ileal sections were evaluated by real-time PCR (qRT-PCR) for IAP, iNOS, IL-1β, IL-6, and TNF-α mRNA and immunofluorescence for 3-nitrotyrosine (3-NT). Experimentally induced NEC decreased IAP mRNA expression by 66% (p ≤ 0.001). IAP supplementation increased IAP mRNA expression to control. Supplemental enteral IAP decreased nitrosative stress as measured by iNOS mRNA expression and 3-NT staining in the NEC stressed pups (p ≤ 0.01), as well as decreased intestinal TNF-α mRNA expression. In addition, IAP decreased LSP translocation into the serum in the treated pups. We conclude that enterally administered IAP prevents NEC-related intestinal injury and inflammation. Enteral IAP may prove a useful strategy in the prevention of NEC in preterm neonates. Copyright © 2013 Elsevier Inc. All rights reserved.
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.
Functions of the nonsense-mediated mRNA decay pathway in Drosophila development.

Directory of Open Access Journals (Sweden)

Mark M Metzstein

2006-12-01

Full Text Available Nonsense-mediated mRNA decay (NMD is a cellular surveillance mechanism that degrades transcripts containing premature translation termination codons, and it also influences expression of certain wild-type transcripts. Although the biochemical mechanisms of NMD have been studied intensively, its developmental functions and importance are less clear. Here, we describe the isolation and characterization of Drosophila "photoshop" mutations, which increase expression of green fluorescent protein and other transgenes. Mapping and molecular analyses show that photoshop mutations are loss-of-function mutations in the Drosophila homologs of NMD genes Upf1, Upf2, and Smg1. We find that Upf1 and Upf2 are broadly active during development, and they are required for NMD as well as for proper expression of dozens of wild-type genes during development and for larval viability. Genetic mosaic analysis shows that Upf1 and Upf2 are required for growth and/or survival of imaginal cell clones, but this defect can be overcome if surrounding wild-type cells are eliminated. By contrast, we find that the PI3K-related kinase Smg1 potentiates but is not required for NMD or for viability, implying that the Upf1 phosphorylation cycle that is required for mammalian and Caenorhabditis elegans NMD has a more limited role during Drosophila development. Finally, we show that the SV40 3' UTR, present in many Drosophila transgenes, targets the transgenes for regulation by the NMD pathway. The results establish that the Drosophila NMD pathway is broadly active and essential for development, and one critical function of the pathway is to endow proliferating imaginal cells with a competitive growth advantage that prevents them from being overtaken by other proliferating cells.
Early Olfactory Processing in Drosophila: Mechanisms and Principles

OpenAIRE

Wilson, Rachel I.

2013-01-01

In the olfactory system of Drosophila melanogaster, it is relatively straightforward to make in vivo measurements of activity in neurons corresponding to targeted processing. This, together with the numerical simplicity of the Drosophila olfactory system, has produced rapid gains in our understanding of Drosophila olfaction. This review summarizes the neurophysiology of the first two layers of this system: the peripheral olfactory receptor neurons and their postsynaptic targets in the antenna...
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

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.
Adaptive genic evolution in the Drosophila genomes

DEFF Research Database (Denmark)

Shapiro, Joshua A; Huang, Wei; Zhang, Chenhui

2007-01-01

and stable population. In this study, we sequenced 419 genes from 24 lines of Drosophila melanogaster and its close relatives. Together with data from Drosophila simulans, these data reveal the following. (i) Approximately 10% of the loci in regions of normal recombination are much less polymorphic at silent...... sites than expected, hinting at the action of selective sweeps. (ii) The level of polymorphism is negatively correlated with the rate of nonsynonymous divergence across loci. Thus, even under strict neutrality, the ratio of amino acid to silent nucleotide changes (A:S) between Drosophila species...
Reassignment of Drosophila willistoni Genome Scaffolds to Chromosome II Arms

OpenAIRE

Garcia, Carolina; Delprat, Alejandra; Ruiz, Alfredo; Valente, Vera L. S.

2015-01-01

Drosophila willistoni is a geographically widespread Neotropical species. The genome of strain Gd-H4-1 from Guadeloupe Island (Caribbean) was sequenced in 2007 as part of the 12 Drosophila Genomes Project. The assembled scaffolds were joined based on conserved linkage and assigned to polytene chromosomes based on a handful of genetic and physical markers. This paucity of markers was particularly striking in the metacentric chromosome II, comprised two similarly sized arms, IIL and IIR, tradit...
An automated paradigm for Drosophila visual psychophysics.

Directory of Open Access Journals (Sweden)

Oliver Evans

Full Text Available BACKGROUND: Mutations that cause learning and memory defects in Drosophila melanogaster have been found to also compromise visual responsiveness and attention. A better understanding of attention-like defects in such Drosophila mutants therefore requires a more detailed characterization of visual responsiveness across a range of visual parameters. METHODOLOGY/PRINCIPAL FINDINGS: We designed an automated behavioral paradigm for efficiently dissecting visual responsiveness in Drosophila. Populations of flies walk through multiplexed serial choice mazes while being exposed to moving visuals displayed on computer monitors, and infra-red fly counters at the end of each maze automatically score the responsiveness of a strain. To test our new design, we performed a detailed comparison between wild-type flies and a learning and memory mutant, dunce(1. We first confirmed that the learning mutant dunce(1 displays increased responsiveness to a black/green moving grating compared to wild type in this new design. We then extended this result to explore responses to a wide range of psychophysical parameters for moving gratings (e.g., luminosity, contrast, spatial frequency, velocity as well as to a different stimulus, moving dots. Finally, we combined these visuals (gratings versus dots in competition to investigate how dunce(1 and wild-type flies respond to more complex and conflicting motion effects. CONCLUSIONS/SIGNIFICANCE: We found that dunce(1 responds more strongly than wild type to high contrast and highly structured motion. This effect was found for simple gratings, dots, and combinations of both stimuli presented in competition.
Sleep deprivation specifically impairs short-term olfactory memory in Drosophila.

Science.gov (United States)

Li, Xinjian; Yu, Feng; Guo, Aike

2009-11-01

Sleep is crucial to memory consolidation in humans and other animals; however, the effect of insufficient sleep on subsequent learning and memory remains largely elusive. Learning and memory after 1-day sleep deprivation (slpD) was evaluated using Pavlovian olfactory conditioning in Drosophila, and locomotor activity was measured using the Drosophila Activity Monitoring System in a 12:12 light-dark cycle. We found that slpD specifically impaired 1-h memory in wild type Canton-S flies, and this effect could persist for at least 2 h. However, alternative stresses (heat stress, oxidative stress, starvation, and rotation stress) did not result in a similar effect and left the flies' memory intact. Mechanistic studies demonstrated that flies with either silenced transmission of the mushroom body (MB) during slpD or down-regulated cAMP levels in the MB demonstrated no slpD-induced 1-h memory impairment. We found that slpD specifically impaired 1-h memory in Drosophila, and either silencing of MB transmission during slpD or down-regulation of the cAMP level in the MB protected the flies from slpD-induced impairment.
Recombining without Hotspots: A Comprehensive Evolutionary Portrait of Recombination in Two Closely Related Species of Drosophila.

Science.gov (United States)

Smukowski Heil, Caiti S; Ellison, Chris; Dubin, Matthew; Noor, Mohamed A F

2015-10-01

Meiotic recombination rate varies across the genome within and between individuals, populations, and species in virtually all taxa studied. In almost every species, this variation takes the form of discrete recombination hotspots, determined in some mammals by a protein called PRDM9. Hotspots and their determinants have a profound effect on the genomic landscape, and share certain features that extend across the tree of life. Drosophila, in contrast, are anomalous in their absence of hotspots, PRDM9, and other species-specific differences in the determination of recombination. To better understand the evolution of meiosis and general patterns of recombination across diverse taxa, we present a truly comprehensive portrait of recombination across time, combining recently published cross-based contemporary recombination estimates from each of two sister species with newly obtained linkage-disequilibrium-based historic estimates of recombination from both of these species. Using Drosophila pseudoobscura and Drosophila miranda as a model system, we compare recombination rate between species at multiple scales, and we suggest that Drosophila replicate the pattern seen in human-chimpanzee in which recombination rate is conserved at broad scales. We also find evidence of a species-wide recombination modifier(s), resulting in both a present and historic genome-wide elevation of recombination rates in D. miranda, and identify broad scale effects on recombination from the presence of an inversion. Finally, we reveal an unprecedented view of the distribution of recombination in D. pseudoobscura, illustrating patterns of linked selection and where recombination is taking place. Overall, by combining these estimation approaches, we highlight key similarities and differences in recombination between Drosophila and other organisms. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Pharmacodynamic study on insomnia-curing effects of Shuangxia Decoction in Drosophila melanogaster.

Science.gov (United States)

Zhang, Zhi-Qian; Degejin; Geng, Di; Zhang, Qi; Tian, Yan; Xi, Yuan; Wang, Wen-Qi; Tang, Hua-Qi; Xu, Bing; Lin, Hong-Ying; Sun, Yi-Kun

2016-09-01

The present study aimed to establish a pharmacodynamic method using the pySolo software to explore the influence of freeze-dried powders of Shuangxia Decoction (SXD) on the sleep of normal Drosophila melanogaster and the Drosophila melanogaster whose sleep was divested by light. The dose-effect and the time-effect relationships of SXD on sleep were examined. The effect-onset concentration of SXD was 0.25%, the plateau appeared at the concentration of 2.5% and the total sleep time showed a downtrend when the concentration was greater than 2.5%. The sleep time was the longest on the fourth day after SXD was given. The fruit fly sleep deprivation model was repeated by light stimulation at night. The middle dosage group (2.5%) had the best insomnia-curing effect. In conclusion, using the pySolo software, an approach for the pharmacodynamics study was established with Drosophila melanogaster as a model organism to determine the insomnia-curing effects of the traditional Chinese medicine (TCM). Our results demonstrated the reliability of this method. The freeze-dried powders of SXD could effectively improve the sleep quality of Drosophila melanogaster. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.
40 CFR 798.5955 - Heritable translocation test in drosophila melanogaster.

Science.gov (United States)

2010-07-01

... drosophila melanogaster. 798.5955 Section 798.5955 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....5955 Heritable translocation test in drosophila melanogaster. (a) Purpose. The heritable translocation test in Drosophila measures the induction of chromosomal translocations in germ cells of insects...
Single Nucleotide Polymorphism Markers for Genetic Mapping in Drosophila melanogaster

OpenAIRE

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

2001-01-01

For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that recently have revolutionized human, mouse, and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila by using a sequence tagged site-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that sp...
Medium-term changes in Drosophila subobscura chromosomal ...

Indian Academy of Sciences (India)

2015-06-02

Jun 2, 2015 ... Krimbas C. B. 1993 Drosophila subobscura: biology, genetics and inversion polymorphism. Verlag Dr, Kovac, Hamburg. Menozzi P. and Krimbas C. B. 1992 The inversion polymorphism of Drosophila subobscura revisited: synthetic maps of gene arrangements frequencies and their interpretation. J. Evol.

Fragile X mental retardation protein regulates trans-synaptic signaling in Drosophila

Directory of Open Access Journals (Sweden)

Samuel H. Friedman

2013-11-01

Fragile X syndrome (FXS, the most common inherited determinant of intellectual disability and autism spectrum disorders, is caused by loss of the fragile X mental retardation 1 (FMR1 gene product (FMRP, an mRNA-binding translational repressor. A number of conserved FMRP targets have been identified in the well-characterized Drosophila FXS disease model, but FMRP is highly pleiotropic in function and the full spectrum of FMRP targets has yet to be revealed. In this study, screens for upregulated neural proteins in Drosophila fmr1 (dfmr1 null mutants reveal strong elevation of two synaptic heparan sulfate proteoglycans (HSPGs: GPI-anchored glypican Dally-like protein (Dlp and transmembrane Syndecan (Sdc. Our recent work has shown that Dlp and Sdc act as co-receptors regulating extracellular ligands upstream of intracellular signal transduction in multiple trans-synaptic pathways that drive synaptogenesis. Consistently, dfmr1 null synapses exhibit altered WNT signaling, with changes in both Wingless (Wg ligand abundance and downstream Frizzled-2 (Fz2 receptor C-terminal nuclear import. Similarly, a parallel anterograde signaling ligand, Jelly belly (Jeb, and downstream ERK phosphorylation (dpERK are depressed at dfmr1 null synapses. In contrast, the retrograde BMP ligand Glass bottom boat (Gbb and downstream signaling via phosphorylation of the transcription factor MAD (pMAD seem not to be affected. To determine whether HSPG upregulation is causative for synaptogenic defects, HSPGs were genetically reduced to control levels in the dfmr1 null background. HSPG correction restored both (1 Wg and Jeb trans-synaptic signaling, and (2 synaptic architecture and transmission strength back to wild-type levels. Taken together, these data suggest that FMRP negatively regulates HSPG co-receptors controlling trans-synaptic signaling during synaptogenesis, and that loss of this regulation causes synaptic structure and function defects characterizing the FXS disease state.
The histone deacetylase HDAC1 positively regulates Notch signaling during Drosophila wing development

Directory of Open Access Journals (Sweden)

Zehua Wang

2018-02-01

Full Text Available The Notch signaling pathway is highly conserved across different animal species and plays crucial roles in development and physiology. Regulation of Notch signaling occurs at multiple levels in different tissues and cell types. Here, we show that the histone deacetylase HDAC1 acts as a positive regulator of Notch signaling during Drosophila wing development. Depletion of HDAC1 causes wing notches on the margin of adult wing. Consistently, the expression of Notch target genes is reduced in the absence of HDAC1 during wing margin formation. We further provide evidence that HDAC1 acts upstream of Notch activation. Mechanistically, we show that HDAC1 regulates Notch protein levels by promoting Notch transcription. Consistent with this, the HDAC1-associated transcriptional co-repressor Atrophin (Atro is also required for transcriptional activation of Notch in the wing disc. In summary, our results demonstrate that HDAC1 positively regulates Notch signaling and reveal a previously unidentified function of HDAC1 in Notch signaling.
Ctr9, a Key Component of the Paf1 Complex, Affects Proliferation and Terminal Differentiation in the Developing Drosophila Nervous System

Directory of Open Access Journals (Sweden)

Shahrzad Bahrampour

2016-10-01

Full Text Available The Paf1 protein complex (Paf1C is increasingly recognized as a highly conserved and broadly utilized regulator of a variety of transcriptional processes. These include the promotion of H3K4 and H3K36 trimethylation, H2BK123 ubiquitination, RNA Pol II transcriptional termination, and also RNA-mediated gene silencing. Paf1C contains five canonical protein components, including Paf1 and Ctr9, which are critical for overall complex integrity, as well as Rtf1, Leo1, and Cdc73/Parafibromin(Hrpt2/Hyrax. In spite of a growing appreciation for the importance of Paf1C from yeast and mammalian studies, there has only been limited work in Drosophila. Here, we provide the first detailed phenotypic study of Ctr9 function in Drosophila. We found that Ctr9 mutants die at late embryogenesis or early larval life, but can be partly rescued by nervous system reexpression of Ctr9. We observed a number of phenotypes in Ctr9 mutants, including increased neuroblast numbers, increased nervous system proliferation, as well as downregulation of many neuropeptide genes. Analysis of cell cycle and regulatory gene expression revealed upregulation of the E2f1 cell cycle factor, as well as changes in Antennapedia and Grainy head expression. We also found reduction of H3K4me3 modification in the embryonic nervous system. Genome-wide transcriptome analysis points to additional downstream genes that may underlie these Ctr9 phenotypes, revealing gene expression changes in Notch pathway target genes, cell cycle genes, and neuropeptide genes. In addition, we find significant effects on the gene expression of metabolic genes. These findings reveal that Ctr9 is an essential gene that is necessary at multiple stages of nervous system development, and provides a starting point for future studies of the Paf1C in Drosophila.
Ostreid herpesvirus type 1 replication and host response in adult Pacific oysters, Crassostrea gigas.

Science.gov (United States)

Segarra, Amélie; Baillon, Laury; Tourbiez, Delphine; Benabdelmouna, Abdellah; Faury, Nicole; Bourgougnon, Nathalie; Renault, Tristan

2014-10-08

Since 2008, massive mortality outbreaks associated with OsHV-1 detection have been reported in Crassostrea gigas spat and juveniles in several countries. Nevertheless, adult oysters do not demonstrate mortality in the field related to OsHV-1 detection and were thus assumed to be more resistant to viral infection. Determining how virus and adult oyster interact is a major goal in understanding why mortality events are not reported among adult Pacific oysters. Dual transcriptomics of virus-host interactions were explored by real-time PCR in adult oysters after a virus injection. Thirty-nine viral genes and five host genes including MyD88, IFI44, IkB2, IAP and Gly were measured at 0.5, 10, 26, 72 and 144 hours post infection (hpi). No viral RNA among the 39 genes was detected at 144 hpi suggesting the adult oysters are able to inhibit viral replication. Moreover, the IAP gene (oyster gene) shows significant up-regulation in infected adults compared to control adults. This result suggests that over-expression of IAP could be a reaction to OsHV-1 infection, which may induce the apoptotic process. Apoptosis could be a main mechanism involved in disease resistance in adults. Antiviral activity of haemolymph against herpes simplex virus (HSV-1) was not significantly different between infected adults versus control.
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.
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.

2016-01-01

We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus. PMID:26901196
Humidity implications for populations of Drosophila suzukii (Diptera: Drosophilidae) on blueberry

Science.gov (United States)

Temperature and humidity affect insect physiology, survival, fecundity, reproductive status and behavior. Drosophila suzukii is an invasive pest of soft-skinned fruit and can cause severe economic losses in a wide range of susceptible crops. This study was conducted on blueberries to determine the e...
Metal-metal interaction mediates the iron induction of Drosophila MtnB

International Nuclear Information System (INIS)

Qiang, Wenjia; Huang, Yunpeng; Wan, Zhihui; Zhou, Bing

2017-01-01

Metallothionein (MT) protein families are a class of small and universal proteins rich in cysteine residues. They are synthesized in response to heavy metal stresses to sequester the toxic ions by metal-thiolate bridges. Five MT family members, namely MtnA, MtnB, MtnC, MtnD and MtnE, have been discovered and identified in Drosophila. These five isoforms of MTs are regulated by metal responsive transcription factor dMTF-1 and play differentiated but overlapping roles in detoxification of metal ions. Previous researches have shown that Drosophila MtnB responds to copper (Cu), cadmium (Cd) and zinc (Zn). Interestingly in this study we found that Drosophila MtnB expression also responds to elevated iron levels in the diet. Further investigations revealed that MtnB plays limited roles in iron detoxification, and the direct binding of MtnB to ferrous iron in vitro is also weak. The induction of MtnB by iron turns out to be mediated by iron interference of other metals, because EDTA at even a partial concentration of that of iron can suppress this induction. Indeed, in the presence of iron, zinc homeostasis is altered, as reflected by expression changes of zinc transporters dZIP1 and dZnT1. Thus, iron-mediated MtnB induction appears resulting from interrupted homeostasis of other metals such as zinc, which in turns induced MtnB expression. Metal-metal interaction may more widely exist than we expected. - Highlights: • Metallothionein B expression is regulated by iron in Drosophila melanogaster. • MtnB has limited physiological roles in iron detoxification. • Binding affinity of MtnB to iron is weak in vitro. • Induction of Drosophila MtnB by iron is mediated indirectly through metal-metal interaction.
Identification and characterization of novel natural pathogen of Drosophila melanogaster isolated from wild captured Drosophila spp.

Science.gov (United States)

Singh, Karan; Zulkifli, Mohammad; Prasad, N G

2016-12-01

Drosophila melanogaster is an emerging model system for the study of evolutionary ecology of immunity. However, a large number of studies have used non natural pathogens as very few natural pathogens have been isolated and identified. Our aim was to isolate and characterize natural pathogen/s of D. melanogaster. A bacterial pathogen was isolated from wild caught Drosophila spp., identified as a new strain of Staphylococcus succinus subsp. succinus and named PK-1. This strain induced substantial mortality (36-62%) in adults of several laboratory populations of D. melanogaster. PK-1 grew rapidly within the body of the flies post infection and both males and females had roughly same number of colony forming units. Mortality was affected by mode of infection and dosage of the pathogen. However mating status of the host had no effect on mortality post infection. Given that there are very few known natural bacterial pathogens of D. melanogaster and that PK-1 can establish a sustained infection across various outbred and inbred populations of D. melanogaster this new isolate is a potential resource for future studies on immunity. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
[Drosophila melanogaster as a model for studying the function of animal viral proteins].

Science.gov (United States)

Omelianchuk, L V; Iudina, O S

2011-07-01

Studies in which Drosophila melanogaster individuals carrying transgenes of animal viruses were used to analyze the action of animal viral proteins on the cell are reviewed. The data presented suggest that host specificity of viruses is determined by their proteins responsible for the penetration of the virus into the cell, while viral proteins responsible for interactions with the host cell are much less host-specific. Due to this, the model of Drosophila with its developed system of searching for genetic interactions can be used to find intracellular targets for the action of viral proteins of the second group.
Modeling Fragile X Syndrome in Drosophila

Science.gov (United States)

Drozd, Małgorzata; Bardoni, Barbara; Capovilla, Maria

2018-01-01

Intellectual disability (ID) and autism are hallmarks of Fragile X Syndrome (FXS), a hereditary neurodevelopmental disorder. The gene responsible for FXS is Fragile X Mental Retardation gene 1 (FMR1) encoding the Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein involved in RNA metabolism and modulating the expression level of many targets. Most cases of FXS are caused by silencing of FMR1 due to CGG expansions in the 5′-UTR of the gene. Humans also carry the FXR1 and FXR2 paralogs of FMR1 while flies have only one FMR1 gene, here called dFMR1, sharing the same level of sequence homology with all three human genes, but functionally most similar to FMR1. This enables a much easier approach for FMR1 genetic studies. Drosophila has been widely used to investigate FMR1 functions at genetic, cellular, and molecular levels since dFMR1 mutants have many phenotypes in common with the wide spectrum of FMR1 functions that underlay the disease. In this review, we present very recent Drosophila studies investigating FMRP functions at genetic, cellular, molecular, and electrophysiological levels in addition to research on pharmacological treatments in the fly model. These studies have the potential to aid the discovery of pharmacological therapies for FXS. PMID:29713264
Drosophila melanogaster as a model organism to study nanotoxicity.

Science.gov (United States)

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

2015-05-01

Drosophila melanogaster has been used as an in vivo model organism for the study of genetics and development since 100 years ago. Recently, the fruit fly Drosophila was also developed as an in vivo model organism for toxicology studies, in particular, the field of nanotoxicity. The incorporation of nanomaterials into consumer and biomedical products is a cause for concern as nanomaterials are often associated with toxicity in many in vitro studies. In vivo animal studies of the toxicity of nanomaterials with rodents and other mammals are, however, limited due to high operational cost and ethical objections. Hence, Drosophila, a genetically tractable organism with distinct developmental stages and short life cycle, serves as an ideal organism to study nanomaterial-mediated toxicity. This review discusses the basic biology of Drosophila, the toxicity of nanomaterials, as well as how the Drosophila model can be used to study the toxicity of various types of nanomaterials.
Drosophila's contribution to stem cell research [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Gyanesh Singh

2016-08-01

Full Text Available The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub. Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila.
Activation of PLC by an endogenous cytokine (GBP) in Drosophila S3 cells and its application as a model for studying inositol phosphate signalling through ITPK1.

Science.gov (United States)

Zhou, Yixing; Wu, Shilan; Wang, Huanchen; Hayakawa, Yoichi; Bird, Gary S; Shears, Stephen B

2012-12-01

Using immortalized [3H]inositol-labelled S3 cells, we demonstrated in the present study that various elements of the inositol phosphate signalling cascade are recruited by a Drosophila homologue from a cytokine family of so-called GBPs (growth-blocking peptides). HPLC analysis revealed that dGBP (Drosophila GBP) elevated Ins(1,4,5)P3 levels 9-fold. By using fluorescent Ca2+ probes, we determined that dGBP initially mobilized Ca2+ from intracellular pools; the ensuing depletion of intracellular Ca2+ stores by dGBP subsequently activated a Ca2+ entry pathway. The addition of dsRNA (double-stranded RNA) to knock down expression of the Drosophila Ins(1,4,5)P3 receptor almost completely eliminated mobilization of intracellular Ca2+ stores by dGBP. Taken together, the results of the present study describe a classical activation of PLC (phospholipase C) by dGBP. The peptide also promoted increases in the levels of other inositol phosphates with signalling credentials: Ins(1,3,4,5)P4, Ins(1,4,5,6)P4 and Ins(1,3,4,5,6)P5. These results greatly expand the regulatory repertoire of the dGBP family, and also characterize S3 cells as a model for studying the regulation of inositol phosphate metabolism and signalling by endogenous cell-surface receptors. We therefore created a cell-line (S3ITPK1) in which heterologous expression of human ITPK (inositol tetrakisphosphate kinase) was controlled by an inducible metallothionein promoter. We found that dGBP-stimulated S3ITPK1 cells did not synthesize Ins(3,4,5,6)P4, contradicting a hypothesis that the PLC-coupled phosphotransferase activity of ITPK1 [Ins(1,3,4,5,6)P5+Ins(1,3,4)P3→Ins(3,4,5,6)P4+Ins(1,3,4,6)P4] is driven solely by the laws of mass action [Chamberlain, Qian, Stiles, Cho, Jones, Lesley, Grabau, Shears and Spraggon (2007) J. Biol. Chem. 282, 28117-28125]. This conclusion represents a fundamental breach in our understanding of ITPK1 signalling.
Mood stabilizing drugs regulate transcription of immune, neuronal and metabolic pathway genes in Drosophila.

Science.gov (United States)

Herteleer, L; Zwarts, L; Hens, K; Forero, D; Del-Favero, J; Callaerts, P

2016-05-01

Lithium and valproate (VPA) are drugs used in the management of bipolar disorder. Even though they reportedly act on various pathways, the transcriptional targets relevant for disease mechanism and therapeutic effect remain unclear. Furthermore, multiple studies used lymphoblasts of bipolar patients as a cellular proxy, but it remains unclear whether peripheral cells provide a good readout for the effects of these drugs in the brain. We used Drosophila culture cells and adult flies to analyze the transcriptional effects of lithium and VPA and define mechanistic pathways. Transcriptional profiles were determined for Drosophila S2-cells and adult fly heads following lithium or VPA treatment. Gene ontology categories were identified using the DAVID functional annotation tool with a cut-off of p neuronal development, neuronal function, and metabolism. (i) Transcriptional effects of lithium and VPA in Drosophila S2 cells and heads show significant overlap. (ii) The overlap between transcriptional alterations in peripheral versus neuronal cells at the single gene level is negligible, but at the gene ontology and pathway level considerable overlap can be found. (iii) Lithium and VPA act on evolutionarily conserved pathways in Drosophila and mammalian models.
CHROMOSOMAL DIFFERENTIATIONS OF THE LAMPBRUSH TYPE FORMED BY THE Y CHROMOSOME IN DROSOPHILA HYDEI AND DROSOPHILA NEOHYDEI

Science.gov (United States)

Hess, Oswald; Meyer, Günther F.

1963-01-01

The nuclei of growing spermatocytes in Drosophila hydei and D. neohydei are characterized by the appearance of phase-specific, paired, loop-shaped structures thought to be similar to the loops in lampbrush chromosomes of amphibian oocytes. In X/O-males of D. hydei spermatogenesis is completely blocked before the first maturation division. No spermatozoa are formed in such testes. In the nuclei of X/O-spermatocytes, paired loop formations are absent. This shows the dependence of these chromosomal functional structures upon the Y chromosome. The basis of this dependence could be shown through an investigation of males with two Y chromosomes. All loop pairs are present in duplicate in XYY males. This proves that the intranuclear formations are structural modifications of the Y chromosome itself. These functional structures are species-specific and characteristically different in Drosophila hydei and D. neohydei. Reciprocal species crosses and a backcross showed that the spermatocyte nuclei of all hybrid males possess the functional structures corresponding to the species which donated the Y chromosome. This shows that the morphological character of the functional structures is also determined by the Y chromosome. PMID:13954225
Rapid and highly accurate detection of Drosophila suzukii, spotted wing Drosophila (Diptera: Drosophilidae) by loop-mediated isothermal amplification assays

Science.gov (United States)

Drosophila suzukii, the spotted wing drosophila (SWD), is currently a major pest that causes severe economic losses to thin-skinned, small fruit growers in North America and Europe. The monitoring and early detection of SWD in the field is of the utmost importance for its proper management. Althou...
Genomic and Transcriptomic Associations Identify a New Insecticide Resistance Phenotype for the Selective Sweep at the Cyp6g1 Locus of Drosophila melanogaster.

Science.gov (United States)

Battlay, Paul; Schmidt, Joshua M; Fournier-Level, Alexandre; Robin, Charles

2016-08-09

Scans of the Drosophila melanogaster genome have identified organophosphate resistance loci among those with the most pronounced signature of positive selection. In this study, the molecular basis of resistance to the organophosphate insecticide azinphos-methyl was investigated using the Drosophila Genetic Reference Panel, and genome-wide association. Recently released full transcriptome data were used to extend the utility of the Drosophila Genetic Reference Panel resource beyond traditional genome-wide association studies to allow systems genetics analyses of phenotypes. We found that both genomic and transcriptomic associations independently identified Cyp6g1, a gene involved in resistance to DDT and neonicotinoid insecticides, as the top candidate for azinphos-methyl resistance. This was verified by transgenically overexpressing Cyp6g1 using natural regulatory elements from a resistant allele, resulting in a 6.5-fold increase in resistance. We also identified four novel candidate genes associated with azinphos-methyl resistance, all of which are involved in either regulation of fat storage, or nervous system development. In Cyp6g1, we find a demonstrable resistance locus, a verification that transcriptome data can be used to identify variants associated with insecticide resistance, and an overlap between peaks of a genome-wide association study, and a genome-wide selective sweep analysis. Copyright © 2016 Battlay et al.
Viruses and Antiviral Immunity in Drosophila

Science.gov (United States)

Xu, Jie; Cherry, Sara

2013-01-01

Viral pathogens present many challenges to organisms, driving the evolution of a myriad of antiviral strategies to combat infections. A wide variety of viruses infect invertebrates, including both natural pathogens that are insect-restricted, and viruses that are transmitted to vertebrates. Studies using the powerful tools available in the model organism Drosophila have expanded our understanding of antiviral defenses against diverse viruses. In this review, we will cover three major areas. First, we will describe the tools used to study viruses in Drosophila. Second, we will survey the major viruses that have been studied in Drosophila. And lastly, we will discuss the well-characterized mechanisms that are active against these diverse pathogens, focusing on non-RNAi mediated antiviral mechanisms. Antiviral RNAi is discussed in another paper in this issue. PMID:23680639
Receptor Tyrosine Kinases in Drosophila Development

Science.gov (United States)

Sopko, Richelle; Perrimon, Norbert

2013-01-01

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

Anatomy and behavioral function of serotonin receptors in Drosophila melanogaster larvae.

Directory of Open Access Journals (Sweden)

Annina Huser

Full Text Available The biogenic amine serotonin (5-HT is an important neuroactive molecule in the central nervous system of the majority of animal phyla. 5-HT binds to specific G protein-coupled and ligand-gated ion receptors to regulate particular aspects of animal behavior. In Drosophila, as in many other insects this includes the regulation of locomotion and feeding. Due to its genetic amenability and neuronal simplicity the Drosophila larva has turned into a useful model for studying the anatomical and molecular basis of chemosensory behaviors. This is particularly true for the olfactory system, which is mostly described down to the synaptic level over the first three orders of neuronal information processing. Here we focus on the 5-HT receptor system of the Drosophila larva. In a bipartite approach consisting of anatomical and behavioral experiments we describe the distribution and the implications of individual 5-HT receptors on naïve and acquired chemosensory behaviors. Our data suggest that 5-HT1A, 5-HT1B, and 5-HT7 are dispensable for larval naïve olfactory and gustatory choice behaviors as well as for appetitive and aversive associative olfactory learning and memory. In contrast, we show that 5-HT/5-HT2A signaling throughout development, but not as an acute neuronal function, affects associative olfactory learning and memory using high salt concentration as a negative unconditioned stimulus. These findings describe for the first time an involvement of 5-HT signaling in learning and memory in Drosophila larvae. In the longer run these results may uncover developmental, 5-HT dependent principles related to reinforcement processing possibly shared with adult Drosophila and other insects.
Effect of Hawthorn on Drosophila Melanogaster Antioxidant-Related ...

African Journals Online (AJOL)

Results: The results indicate that hawthorn extract prolonged the life span of Drosophila, with 50 % survival time of 0.8 ... Drosophila's aging gene is highly similar to humans [4,5]. ..... reduces lipid peroxidation in senescence-accelerated mice .
Nutritional control of gene expression in Drosophila larvae via TOR, Myc and a novel cis-regulatory element

Directory of Open Access Journals (Sweden)

Grewal Savraj S

2010-01-01

Full Text Available Abstract Background Nutrient availability is a key determinant of eukaryotic cell growth. In unicellular organisms many signaling and transcriptional networks link nutrient availability to the expression of metabolic genes required for growth. However, less is known about the corresponding mechanisms that operate in metazoans. We used gene expression profiling to explore this issue in developing Drosophila larvae. Results We found that starvation for dietary amino acids (AA's leads to dynamic changes in transcript levels of many metabolic genes. The conserved insulin/PI3K and TOR signaling pathways mediate nutrition-dependent growth in Drosophila and other animals. We found that many AA starvation-responsive transcripts were also altered in TOR mutants. In contrast, although PI3K overexpression induced robust changes in the expression of many metabolic genes, these changes showed limited overlap with the AA starvation expression profile. We did however identify a strong overlap between genes regulated by the transcription factor, Myc, and AA starvation-responsive genes, particularly those involved in ribosome biogenesis, protein synthesis and mitochondrial function. The consensus Myc DNA binding site is enriched in promoters of these AA starvation genes, and we found that Myc overexpression could bypass dietary AA to induce expression of these genes. We also identified another sequence motif (Motif 1 enriched in the promoters of AA starvation-responsive genes. We showed that Motif 1 was both necessary and sufficient to mediate transcriptional responses to dietary AA in larvae. Conclusions Our data suggest that many of the transcriptional effects of amino acids are mediated via signaling through the TOR pathway in Drosophila larvae. We also find that these transcriptional effects are mediated through at least two mechanisms: via the transcription factor Myc, and via the Motif 1 cis-regulatory element. These studies begin to elucidate a nutrient
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.
Developing a Drosophila Model of Schwannomatosis

Science.gov (United States)

2013-02-01

processed for ChIP as described above. Cell culture and dsRNA S2 cells were cultured at 25°C in Schneider’s insect medium (Sigma; 10% fetal bovine serum...destroy pathogens. In Drosophila, circulating blood cells called hemocytes phagocytose bacteria, fungi, and parasitic wasp eggs [28]. RBF1 and dCAP-D3...hTERT-RPE-1 cells were grown in Dulbecco’sModified Essential Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and 1% penicillin
Characterization of dFOXO binding sites upstream of the Insulin Receptor P2 promoter across the Drosophila phylogeny.

Directory of Open Access Journals (Sweden)

Dorcas J Orengo

Full Text Available The insulin/TOR signal transduction pathway plays a critical role in determining such important traits as body and organ size, metabolic homeostasis and life span. Although this pathway is highly conserved across the animal kingdom, the affected traits can exhibit important differences even between closely related species. Evolutionary studies of regulatory regions require the reliable identification of transcription factor binding sites. Here we have focused on the Insulin Receptor (InR expression from its P2 promoter in the Drosophila genus, which in D. melanogaster is up-regulated by hypophosphorylated Drosophila FOXO (dFOXO. We have finely characterized this transcription factor binding sites in vitro along the 1.3 kb region upstream of the InR P2 promoter in five Drosophila species. Moreover, we have tested the effect of mutations in the characterized dFOXO sites of D. melanogaster in transgenic flies. The number of experimentally established binding sites varies across the 1.3 kb region of any particular species, and their distribution also differs among species. In D. melanogaster, InR expression from P2 is differentially affected by dFOXO binding sites at the proximal and distal halves of the species 1.3 kb fragment. The observed uneven distribution of binding sites across this fragment might underlie their differential contribution to regulate InR transcription.
PICK1 expression in the Drosophila central nervous system primarily occurs in the neuroendocrine system

DEFF Research Database (Denmark)

Jansen, Anna M; Nässel, Dick R; Madsen, Kenneth L

2009-01-01

in the adult and larval Drosophila central nervous system. PICK1 was found in cell bodies in the subesophageal ganglion, the antennal lobe, the protocerebrum, and the neuroendocrine center pars intercerebralis. The cell types that express PICK1 were identified using GAL4 enhancer trap lines. The PICK1...... (AMPA) receptor subunit GluR2 and the dopamine transporter. PICK1 is strongly implicated in GluR2 trafficking and synaptic plasticity. In mammals, PICK1 has been characterized extensively in cell culture studies. To study PICK1 in an intact system, we characterized PICK1 expression immunohistochemically...... neurons in the neuroendocrine system, which express the transcription factor DIMM and the amidating enzyme peptidylglycine-alpha-hydroxylating monooxygenase (PHM). The PICK1-positive cells include neurosecretory cells that produce the insulin-like peptide dILP2. PICK1 expression in insulin-producing cells...
Preference for and learning of amino acids in larval Drosophila

Directory of Open Access Journals (Sweden)

Nana Kudow

2017-03-01

Full Text Available Relative to other nutrients, less is known about how animals sense amino acids and how behaviour is organized accordingly. This is a significant gap in our knowledge because amino acids are required for protein synthesis − and hence for life as we know it. Choosing Drosophila larvae as a case study, we provide the first systematic analysis of both the preference behaviour for, and the learning of, all 20 canonical amino acids in Drosophila. We report that preference for individual amino acids differs according to the kind of amino acid, both in first-instar and in third-instar larvae. Our data suggest that this preference profile changes across larval instars, and that starvation during the third instar also alters this profile. Only aspartic acid turns out to be robustly attractive across all our experiments. The essentiality of amino acids does not appear to be a determinant of preference. Interestingly, although amino acids thus differ in their innate attractiveness, we find that all amino acids are equally rewarding. Similar discrepancies between innate attractiveness and reinforcing effect have previously been reported for other tastants, including sugars, bitter substances and salt. The present analyses will facilitate the ongoing search for the receptors, sensory neurons, and internal, homeostatic amino acid sensors in Drosophila.
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

, 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...... 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...... likelihood framework to 8,452 protein coding sequences with well-defined orthology in D. melanogaster, Drosophila sechellia, and Drosophila yakuba. Our analyses reveal intragenomic and interspecific variation in mutational patterns as well as in patterns and intensity of selection on synonymous sites. In D...
Origin and specification of type II neuroblasts in the Drosophila embryo.

Science.gov (United States)

Álvarez, José-Andrés; Díaz-Benjumea, Fernando J

2018-04-05

In Drosophila , neural stem cells or neuroblasts (NBs) acquire different identities according to their site of origin in the embryonic neuroectoderm. Their identity determines the number of times they will divide and the types of daughter cells they will generate. All NBs divide asymmetrically, with type I NBs undergoing self-renewal and generating another cell that will divide only once more. By contrast, a small set of NBs in the larval brain, type II NBs, divides differently, undergoing self-renewal and generating an intermediate neural progenitor (INP) that continues to divide asymmetrically several more times, generating larger lineages. In this study, we have analysed the origin of type II NBs and how they are specified. Our results indicate that these cells originate in three distinct clusters in the dorsal protocerebrum during stage 12 of embryonic development. Moreover, it appears that their specification requires the combined action of EGFR signalling and the activity of the related genes buttonhead and Drosophila Sp1 In addition, we also show that the INPs generated in the embryo enter quiescence at the end of embryogenesis, resuming proliferation during the larval stage. © 2018. Published by The Company of Biologists Ltd.
Sex determination

Indian Academy of Sciences (India)

The sex-determining system differs considerably among organisms. Even among insect species, the genetic system for sex-determination is highly diversified. In Drosophila melanogaster, somatic sexual differentiation is regulated by a well characterized genetic hierarchy X : A > Sxl > tra/tra2 > dsx and fru. This cascade ...
Evolution of genes and genomes on the Drosophila phylogeny

DEFF Research Database (Denmark)

Clark, Andrew G; Eisen, Michael B; Smith, Douglas R

2007-01-01

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the ......Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here...... tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila...
Tet protein function during Drosophila development.

Directory of Open Access Journals (Sweden)

Fei Wang

Full Text Available The TET (Ten-eleven translocation 1, 2 and 3 proteins have been shown to function as DNA hydroxymethylases in vertebrates and their requirements have been documented extensively. Recently, the Tet proteins have been shown to also hydroxylate 5-methylcytosine in RNA. 5-hydroxymethylcytosine (5hmrC is enriched in messenger RNA but the function of this modification has yet to be elucidated. Because Cytosine methylation in DNA is barely detectable in Drosophila, it serves as an ideal model to study the biological function of 5hmrC. Here, we characterized the temporal and spatial expression and requirement of Tet throughout Drosophila development. We show that Tet is essential for viability as Tet complete loss-of-function animals die at the late pupal stage. Tet is highly expressed in neuronal tissues and at more moderate levels in somatic muscle precursors in embryos and larvae. Depletion of Tet in muscle precursors at early embryonic stages leads to defects in larval locomotion and late pupal lethality. Although Tet knock-down in neuronal tissue does not cause lethality, it is essential for neuronal function during development through its affects upon locomotion in larvae and the circadian rhythm of adult flies. Further, we report the function of Tet in ovarian morphogenesis. Together, our findings provide basic insights into the biological function of Tet in Drosophila, and may illuminate observed neuronal and muscle phenotypes observed in vertebrates.
Estrogen receptor Î² exhibited anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kB/BCL-2 and PI3K/Akt signal pathway

Directory of Open Access Journals (Sweden)

Minfei Yang

2017-11-01

Full Text Available This study aimed to investigate the effects of Estrogen receptor Î² (ERÎ² on osteosarcoma cells, and explore the regulatory mechanisms involved in this process. Osteosarcoma U2-OS cells consisted four groups, and treated by E2, E2 + LY294002 (ERÎ² agonists, E2 + ERÎ² siRNA, E2 + ERÎ² siRNA + LY294002, respectively. Cell counting kit 8 (CCK-8 assay was performed to detect the cell viability of U2-OS cells in each group. The effects of ERÎ² on the migration and invasion ability of U2-OS cells were examined by wound healing assay and transwell cell culture chamber, respectively. The expression of Inhibitor of apoptosis protein (IAP and integrin Î±5 in U2-OS cells of each group was detected by quantitative RT-PCR, and the expression of phosphorylated p65 (p-p65, p-AKT and Bcl-2 was detected by western blotting. The cell viability, migration and invasion ability of U2-OS cells were significantly increased by ERÎ² siRNA, but inhibited by ERÎ² agonists LY294002 (p < 0.05. ERÎ² siRNA significantly downregulated Integrin Î±5 and unregulated IAP in U2-OS cells (p < 0.05. The expression of p-p65, p-AKT and Bcl-2 was significantly reduced by LY294002, but increased by ERÎ² siRNA (p < 0.05. In conclusion, ERÎ² exhibited obvious anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kBBCL-2 and PI3K/Akt signal pathway. Keywords: Estrogen receptor Î², Osteosarcoma, Anti-tumor, Regulatory mechanism
Genetic or pharmacological activation of the Drosophila PGC-1α ortholog spargel rescues the disease phenotypes of genetic models of Parkinson's disease.

Science.gov (United States)

Ng, Chee-Hoe; Basil, Adeline H; Hang, Liting; Tan, Royston; Goh, Kian-Leong; O'Neill, Sharon; Zhang, Xiaodong; Yu, Fengwei; Lim, Kah-Leong

2017-07-01

Despite intensive research, the etiology of Parkinson's disease (PD) remains poorly understood and the disease remains incurable. However, compelling evidence gathered over decades of research strongly support a role for mitochondrial dysfunction in PD pathogenesis. Related to this, PGC-1α, a key regulator of mitochondrial biogenesis, has recently been proposed to be an attractive target for intervention in PD. Here, we showed that silencing of expression of the Drosophila PGC-1α ortholog spargel results in PD-related phenotypes in flies and also seem to negate the effects of AMPK activation, which we have previously demonstrated to be neuroprotective, that is, AMPK-mediated neuroprotection appears to require PGC-1α. Importantly, we further showed that genetic or pharmacological activation of the Drosophila PGC-1α ortholog spargel is sufficient to rescue the disease phenotypes of Parkin and LRRK2 genetic fly models of PD, thus supporting the proposed use of PGC-1α-related strategies for neuroprotection in PD. Copyright © 2017 National Neuroscience Institute. Published by Elsevier Inc. All rights reserved.
Transcriptomic Response of Drosophila Melanogaster Pupae Developed in Hypergravity

Science.gov (United States)

Hosamani, Ravikumar; Hateley, Shannon; Bhardwaj, Shilpa R.; Pachter, Lior; Bhattacharya, Sharmila

2016-01-01

The metamorphosis of Drosophila is evolutionarily adapted to Earth's gravity, and is a tightly regulated process. Deviation from 1g to microgravity or hypergravity can influence metamorphosis, and alter associated gene expression. Understanding the relationship between an altered gravity environment and developmental processes is important for NASA's space travel goals. In the present study, 20 female and 20 male synchronized (Canton S, 2 to 3day old) flies were allowed to lay eggs while being maintained in a hypergravity environment (3g). Centrifugation was briefly stopped to discard the parent flies after 24hrs of egg laying, and then immediately continued until the eggs developed into P6-staged pupae (25 - 43 hours after pupation initiation). Post hypergravity exposure, P6-staged pupae were collected, total RNA was extracted using Qiagen RNeasy mini kits. We used RNA-Seq and qRT-PCR techniques to profile global transcriptomic changes in early pupae exposed to chronic hypergravity. During the pupal stage, Drosophila relies upon gravitational cues for proper development. Assessing gene expression changes in the pupa under altered gravity conditions helps highlight gravity dependent genetic pathways. A robust transcriptional response was observed in hypergravity-exposed pupae compared to controls, with 1,513 genes showing a significant (q Drosophila pupae in response to hypergravity.
Drosophila cell cycle under arrest: uncapped telomeres plead guilty.

Science.gov (United States)

Cenci, Giovanni

2009-04-01

Telomeres are specialized structures that protect chromosome ends from degradation and fusion events. In most organisms, telomeres consist of short, repetitive G-rich sequences added to chromosome ends by a reverse transcriptase with an internal RNA template, called telomerase. Specific DNA-binding protein complexes associate with telomeric sequences preventing chromosome ends from being recognized as DNA double strand breaks (DSBs). Telomeres that lose their cap activate the DNA damage response (DDR) likewise DSBs and, if inappropriately repaired, generate telomeric fusions, which eventually lead to genome instability. In Drosophila there is not telomerase, and telomere length is maintained by transposition of three specialized retroelements. However, fly telomeres are protected by multi protein complexes like their yeast and vertebrate counterparts; these complexes bind chromosome ends in a sequence-independent fashion and are required to prevent checkpoint activation and end-to-end fusion. Uncapped Drosophila telomeres elicit a DDR just as dysfunctional human telomeres. Most interestingly, uncapped Drosophila telomeres also activate the spindle assembly checkpoint (SAC) by recruiting the SAC kinase BubR1. BubR1 accumulations at chromosome ends trigger the SAC that inhibits the metaphase-to-anaphase transition. These findings, reviewed here, highlight an intriguing and unsuspected connection between telomeres and cell cycle regulation, providing a clue to understand human telomere function.
Nematocytes: Discovery and characterization of a novel anculeate hemocyte in Drosophila falleni and Drosophila phalerata.

Directory of Open Access Journals (Sweden)

Julianna Bozler

Full Text Available Immune challenges, such as parasitism, can be so pervasive and deleterious that they constitute an existential threat to a species' survival. In response to these ecological pressures, organisms have developed a wide array of novel behavioral, cellular, and molecular adaptations. Research into these immune defenses in model systems has resulted in a revolutionary understanding of evolution and functional biology. As the field has expanded beyond the limited number of model organisms our appreciation of evolutionary innovation and unique biology has widened as well. With this in mind, we have surveyed the hemolymph of several non-model species of Drosophila. Here we identify and describe a novel hemocyte, type-II nematocytes, found in larval stages of numerous Drosophila species. Examined in detail in Drosophila falleni and Drosophila phalerata, we find that these remarkable cells are distinct from previously described hemocytes due to their anucleate state (lacking a nucleus and unusual morphology. Type-II nematocytes are long, narrow cells with spindle-like projections extending from a cell body with high densities of mitochondria and microtubules, and exhibit the ability to synthesize proteins. These properties are unexpected for enucleated cells, and together with our additional characterization, we demonstrate that these type-II nematocytes represent a biological novelty. Surprisingly, despite the absence of a nucleus, we observe through live cell imaging that these cells remain motile with a highly dynamic cellular shape. Furthermore, these cells demonstrate the ability to form multicellular structures, which we suggest may be a component of the innate immune response to macro-parasites. In addition, live cell imaging points to a large nucleated hemocyte, type-I nematocyte, as the progenitor cell, leading to enucleation through a budding or asymmetrical division process rather than nuclear ejection: This study is the first to report such a
Quantification of Drosophila Grooming Behavior.

Science.gov (United States)

Barradale, Francesca; Sinha, Kairav; Lebestky, Tim

2017-07-19

Drosophila grooming behavior is a complex multi-step locomotor program that requires coordinated movement of both forelegs and hindlegs. Here we present a grooming assay protocol and novel chamber design that is cost-efficient and scalable for either small or large-scale studies of Drosophila grooming. Flies are dusted all over their body with Brilliant Yellow dye and given time to remove the dye from their bodies within the chamber. Flies are then deposited in a set volume of ethanol to solubilize the dye. The relative spectral absorbance of dye-ethanol samples for groomed versus ungroomed animals are measured and recorded. The protocol yields quantitative data of dye accumulation for individual flies, which can be easily averaged and compared across samples. This allows experimental designs to easily evaluate grooming ability for mutant animal studies or circuit manipulations. This efficient procedure is both versatile and scalable. We show work-flow of the protocol and comparative data between WT animals and mutant animals for the Drosophila type I Dopamine Receptor (DopR).
Interorgan Communication Pathways in Physiology: Focus on Drosophila.

Science.gov (United States)

Droujinine, Ilia A; Perrimon, Norbert

2016-11-23

Studies in mammals and Drosophila have demonstrated the existence and significance of secreted factors involved in communication between distal organs. In this review, primarily focusing on Drosophila, we examine the known interorgan communication factors and their functions, physiological inducers, and integration in regulating physiology. Moreover, we describe how organ-sensing screens in Drosophila can systematically identify novel conserved interorgan communication factors. Finally, we discuss how interorgan communication enabled and evolved as a result of specialization of organs. Together, we anticipate that future studies will establish a model for metazoan interorgan communication network (ICN) and how it is deregulated in disease.

Molecular analysis of mutant and wild type alcohol dehydrogenase alleles from Drosophila

International Nuclear Information System (INIS)

Batzer, M.A.

1988-01-01

Wild type alcohol dehydrogenase polypeptides (ADH) from Drosophila melanogaster transformants were examined using western blots and polyclonal antiserum specific for Drosophila melanogaster ADH. Mutants induced in Drosophila spermatozoa at the alcohol dehydrogenase (Adh) locus using X-rays, 1-ethyl-1-nitrosourea (ENU) or ethyl methanesulfonate (EMS) were characterized using genetic complementation tests, western blots, Southern blots, northern blots and enzymatic amplification of the Adh locus. Genetic complementation tests showed that 22/30 X-ray-induced mutants, and 3/13 ENU and EMS induced mutants were multi-locus deficiencies. Western blot analysis of the intragenic mutations showed that 4/7 X-ray-induced mutants produced detectable polypeptides, one of which was normal in molecular weight and charge. In contrast 8/10 intragenic ENU and EMS induced mutants produced normal polypeptides. Southern blot analysis showed that 5/7 intragenic X-ray induced mutants and all 10 of the intragenic ENU and EMS induced mutants were normal with respect to the alleles they were derived from
Acetylcholine receptors and cholinergic ligands: biochemical and genetic aspects in Torpedo californica and Drosophila melanogaster

International Nuclear Information System (INIS)

Rosenthal, L.S.

1987-01-01

This study evaluates the biochemical and genetic aspects of the acetylcholine receptor proteins and cholinergic ligands in Drosophila melanogaster and Torpedo californica. Included are (1) a comparative study of nicotinic ligand-induced cation release from acetylcholine receptors isolated from Torpedo californica and from Drosophila melanogaster, (2) solution studies of the cholinergic ligands, nikethamide and ethamivan, aimed at measuring internal molecular rotational barriers in solvents of different polarity; and (3) the isolation and characterization of the gene(s) for the acetylcholine receptor in Drosophila melasogaster. Acetylcholine receptor proteins isolated from Drosphila melanogaster heads were found to behave kinetically similar (with regards to cholinergic ligand-induced 155 Eu: 3+ displacement from prelabeled proteins) to receptor proteins isolated from Torpedo californica electric tissue, providing additional biochemical evidence for the existence of a Drosophila acetylcholine receptor
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.
Gene expression profiling of brakeless mutant Drosophila embryos.

Science.gov (United States)

Crona, Filip; Singla, Bhumica; Mannervik, Mattias

2015-12-01

The transcriptional co-regulator Brakeless performs many important functions during Drosophila development, but few target genes have been identified. Here we use Affymetrix microarrays to identify Brakeless-regulated genes in 2-4 h old Drosophila embryos. Robust multi-array analysis (RMA) and statistical tests revealed 240 genes that changed their expression more than 1.5 fold. We find that up- and down-regulated genes fall into distinct gene ontology categories. In our associated study [2] we demonstrate that both up- and down-regulated genes can be direct Brakeless targets. Our results indicate that the co-repressor and co-activator activities of Brakeless may result in distinct biological responses. The microarray data complies with MIAME guidelines and is deposited in GEO under accession number GSE60048.
Dietary Intake of Curcuma longa and Emblica officinalis Increases Life Span in Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Shilpa Rawal

2014-01-01

Full Text Available Intake of food and nutrition plays a major role in affecting aging process and longevity. However, the precise mechanisms underlying the ageing process are still unclear. To this respect, diet has been considered to be a determinant of ageing process. In order to better illustrate this, we used Drosophila melanogaster as a model and fed them orally with different concentrations of two commonly used Indian medicinal plant products, Curcuma longa (rhizome and Emblica officinalis (fruit. The results revealed significant increase in life span of Drosophila flies on exposure to both the plant products, more efficiently by C. Longa than by E. officinalis. In order to understand whether the increase in lifespan was due to high-antioxidant properties of these medicinal plants, we performed enzymatic assays to assess the SOD and catalase activities in case of both treated and control Drosophila flies. Interestingly, the results support the free radical theory of aging as both these plant derivatives show high reactive oxygen species (ROS scavenging activities.
Maximum likelihood estimation of ancestral codon usage bias parameters in Drosophila

DEFF Research Database (Denmark)

Nielsen, Rasmus; Bauer DuMont, Vanessa L; Hubisz, Melissa J

2007-01-01

: the selection coefficient for optimal codon usage (S), allowing joint maximum likelihood estimation of S and the dN/dS ratio. We apply the method to previously published data from Drosophila melanogaster, Drosophila simulans, and Drosophila yakuba and show, in accordance with previous results, that the D...
Comprehensive functional analysis of Rab GTPases in Drosophila nephrocytes.

Science.gov (United States)

Fu, Yulong; Zhu, Jun-Yi; Zhang, Fujian; Richman, Adam; Zhao, Zhanzheng; Han, Zhe

2017-06-01

The Drosophila nephrocyte is a critical component of the fly renal system and bears structural and functional homology to podocytes and proximal tubule cells of the mammalian kidney. Investigations of nephrocyte cell biological processes are fundamental to understanding the insect renal system. Nephrocytes are highly active in endocytosis and vesicle trafficking. Rab GTPases regulate endocytosis and trafficking but specific functions of nephrocyte Rabs remain undefined. We analyzed Rab GTPase expression and function in Drosophila nephrocytes and found that 11 out of 27 Drosophila Rabs were required for normal activity. Rabs 1, 5, 7, 11 and 35 were most important. Gene silencing of the nephrocyte-specific Rab5 eliminated all intracellular vesicles and the specialized plasma membrane structures essential for nephrocyte function. Rab7 silencing dramatically increased clear vacuoles and reduced lysosomes. Rab11 silencing increased lysosomes and reduced clear vacuoles. Our results suggest that Rab5 mediates endocytosis that is essential for the maintenance of functionally critical nephrocyte plasma membrane structures and that Rabs 7 and 11 mediate alternative downstream vesicle trafficking pathways leading to protein degradation and membrane recycling, respectively. Elucidating molecular pathways underlying nephrocyte function has the potential to yield important insights into human kidney cell physiology and mechanisms of cell injury that lead to disease. The Drosophila nephrocyte is emerging as a useful in vivo model system for molecular target identification and initial testing of therapeutic approaches in humans.
Metabolomics with Nuclear Magnetic Resonance Spectroscopy in a Drosophila melanogaster Model of Surviving Sepsis

Science.gov (United States)

Bakalov, Veli; Amathieu, Roland; Triba, Mohamed N.; Clément, Marie-Jeanne; Reyes Uribe, Laura; Le Moyec, Laurence; Kaynar, Ata Murat

2016-01-01

Patients surviving sepsis demonstrate sustained inflammation, which has been associated with long-term complications. One of the main mechanisms behind sustained inflammation is a metabolic switch in parenchymal and immune cells, thus understanding metabolic alterations after sepsis may provide important insights to the pathophysiology of sepsis recovery. In this study, we explored metabolomics in a novel Drosophila melanogaster model of surviving sepsis using Nuclear Magnetic Resonance (NMR), to determine metabolite profiles. We used a model of percutaneous infection in Drosophila melanogaster to mimic sepsis. We had three experimental groups: sepsis survivors (infected with Staphylococcus aureus and treated with oral linezolid), sham (pricked with an aseptic needle), and unmanipulated (positive control). We performed metabolic measurements seven days after sepsis. We then implemented metabolites detected in NMR spectra into the MetExplore web server in order to identify the metabolic pathway alterations in sepsis surviving Drosophila. Our NMR metabolomic approach in a Drosophila model of recovery from sepsis clearly distinguished between all three groups and showed two different metabolomic signatures of inflammation. Sham flies had decreased levels of maltose, alanine, and glutamine, while their level of choline was increased. Sepsis survivors had a metabolic signature characterized by decreased glucose, maltose, tyrosine, beta-alanine, acetate, glutamine, and succinate. PMID:28009836
Resources for Functional Genomics Studies in Drosophila melanogaster

Science.gov (United States)

Mohr, Stephanie E.; Hu, Yanhui; Kim, Kevin; Housden, Benjamin E.; Perrimon, Norbert

2014-01-01

Drosophila melanogaster has become a system of choice for functional genomic studies. Many resources, including online databases and software tools, are now available to support design or identification of relevant fly stocks and reagents or analysis and mining of existing functional genomic, transcriptomic, proteomic, etc. datasets. These include large community collections of fly stocks and plasmid clones, “meta” information sites like FlyBase and FlyMine, and an increasing number of more specialized reagents, databases, and online tools. Here, we introduce key resources useful to plan large-scale functional genomics studies in Drosophila and to analyze, integrate, and mine the results of those studies in ways that facilitate identification of highest-confidence results and generation of new hypotheses. We also discuss ways in which existing resources can be used and might be improved and suggest a few areas of future development that would further support large- and small-scale studies in Drosophila and facilitate use of Drosophila information by the research community more generally. PMID:24653003
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. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
Downregulation of dTps1 in Drosophila melanogaster larvae confirms involvement of trehalose in redox regulation following desiccation.

Science.gov (United States)

Thorat, Leena; Mani, Krishna-Priya; Thangaraj, Pradeep; Chatterjee, Suvro; Nath, Bimalendu B

2016-03-01

As a survival strategy to environmental water deficits, desiccation-tolerant organisms are commonly known for their ability to recruit stress-protective biomolecules such as trehalose. We have previously reported the pivotal role of trehalose in larval desiccation tolerance in Drosophila melanogaster. Trehalose has emerged as a versatile molecule, serving mainly as energy source in insects and also being a stress protectant. While several recent reports have revealed the unconventional role of trehalose in scavenging reactive oxygen species in yeast and plants, this aspect has not received much attention in animals. We examined the status of desiccation-induced generation of reactive oxygen species in D. melanogaster larvae and the possible involvement of trehalose in ameliorating the harmful consequences thereof. Insect trehalose synthesis is governed by the enzyme trehalose 6-phosphate synthase 1 (TPS1). Using the ubiquitous da-GAL4-driven expression of the dTps1-RNAi transgene, we generated dTps1-downregulated Drosophila larvae possessing depleted levels of dTps1 transcripts. This resulted in the inability of the larvae for trehalose synthesis, thereby allowing us to elucidate the significance of trehalose in the regulation of desiccation-responsive redox homeostasis. Furthermore, the results from molecular genetics studies, biochemical assays, electron spin resonance analyses and a simple, non-invasive method of whole larval live imaging suggested that trehalose in collaboration with superoxide dismutase (SOD) is involved in the maintenance of redox state in D. melanogaster.
Early events in speciation: polymorphism for hybrid male sterility in Drosophila.

Science.gov (United States)

Reed, Laura K; Markow, Therese A

2004-06-15

Capturing the process of speciation early enough to determine the initial genetic causes of reproductive isolation remains a major challenge in evolutionary biology. We have found, to our knowledge, the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. Specifically, we show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, Drosophila arizonae, is controlled by factors present at different frequencies in different populations of D. mojavensis. In addition, we show that hybrid male sterility is a complex phenotype; some hybrid males with motile sperm still cannot sire offspring. Because male sterility factors in hybrids between these species are not yet fixed within D. mojavensis, this system provides an invaluable opportunity to characterize the genetics of reproductive isolation at an early stage.
Modelling Cooperative Tumorigenesis in Drosophila

Science.gov (United States)

2018-01-01

The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression. PMID:29693007
Modelling Cooperative Tumorigenesis in Drosophila

Directory of Open Access Journals (Sweden)

Helena E. Richardson

2018-01-01

Full Text Available The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression.
A Circadian Clock Gene, Cry, Affects Heart Morphogenesis and Function in Drosophila as Revealed by Optical Coherence Microscopy.

Directory of Open Access Journals (Sweden)

Aneesh Alex

Full Text Available Circadian rhythms are endogenous, entrainable oscillations of physical, mental and behavioural processes in response to local environmental cues such as daylight, which are present in the living beings, including humans. Circadian rhythms have been related to cardiovascular function and pathology. However, the role that circadian clock genes play in heart development and function in a whole animal in vivo are poorly understood. The Drosophila cryptochrome (dCry is a circadian clock gene that encodes a major component of the circadian clock negative feedback loop. Compared to the embryonic stage, the relative expression levels of dCry showed a significant increase (>100-fold in Drosophila during the pupa and adult stages. In this study, we utilized an ultrahigh resolution optical coherence microscopy (OCM system to perform non-invasive and longitudinal analysis of functional and morphological changes in the Drosophila heart throughout its post-embryonic lifecycle for the first time. The Drosophila heart exhibited major morphological and functional alterations during its development. Notably, heart rate (HR and cardiac activity period (CAP of Drosophila showed significant variations during the pupa stage, when heart remodeling took place. From the M-mode (2D + time OCM images, cardiac structural and functional parameters of Drosophila at different developmental stages were quantitatively determined. In order to study the functional role of dCry on Drosophila heart development, we silenced dCry by RNAi in the Drosophila heart and mesoderm, and quantitatively measured heart morphology and function in those flies throughout its development. Silencing of dCry resulted in slower HR, reduced CAP, smaller heart chamber size, pupal lethality and disrupted posterior segmentation that was related to increased expression of a posterior compartment protein, wingless. Collectively, our studies provided novel evidence that the circadian clock gene, dCry, plays
A Circadian Clock Gene, Cry, Affects Heart Morphogenesis and Function in Drosophila as Revealed by Optical Coherence Microscopy

Science.gov (United States)

Zeng, Xianxu; Tate, Rebecca E.; McKee, Mary L.; Capen, Diane E.; Zhang, Zhan; Tanzi, Rudolph E.; Zhou, Chao

2015-01-01

Circadian rhythms are endogenous, entrainable oscillations of physical, mental and behavioural processes in response to local environmental cues such as daylight, which are present in the living beings, including humans. Circadian rhythms have been related to cardiovascular function and pathology. However, the role that circadian clock genes play in heart development and function in a whole animal in vivo are poorly understood. The Drosophila cryptochrome (dCry) is a circadian clock gene that encodes a major component of the circadian clock negative feedback loop. Compared to the embryonic stage, the relative expression levels of dCry showed a significant increase (>100-fold) in Drosophila during the pupa and adult stages. In this study, we utilized an ultrahigh resolution optical coherence microscopy (OCM) system to perform non-invasive and longitudinal analysis of functional and morphological changes in the Drosophila heart throughout its post-embryonic lifecycle for the first time. The Drosophila heart exhibited major morphological and functional alterations during its development. Notably, heart rate (HR) and cardiac activity period (CAP) of Drosophila showed significant variations during the pupa stage, when heart remodeling took place. From the M-mode (2D + time) OCM images, cardiac structural and functional parameters of Drosophila at different developmental stages were quantitatively determined. In order to study the functional role of dCry on Drosophila heart development, we silenced dCry by RNAi in the Drosophila heart and mesoderm, and quantitatively measured heart morphology and function in those flies throughout its development. Silencing of dCry resulted in slower HR, reduced CAP, smaller heart chamber size, pupal lethality and disrupted posterior segmentation that was related to increased expression of a posterior compartment protein, wingless. Collectively, our studies provided novel evidence that the circadian clock gene, dCry, plays an essential
Determination of methyl methanesulfonate pretreatment effect in Drosophila melanogaster larvaes upon repair mechanisms in somatic cells

International Nuclear Information System (INIS)

Hernandez Paz, M.

1992-01-01

To make evident the existence of SOS repair mecanism in somatic cells, larvaes of drosophila melanogaster with MWH markers for females and FLR markers for males were used. This larvaes received a pretreatment with MMS at concentrations of 0.0007% and 0.0014% during 24 hours and latter a treatment with gamma rays at different dosis. SMART program was used to make stastistical evaluations. Small spots were observed which can have two origins. First could be damage in the last part of third stage in which cells are in last divisions and second could be the damage to larvaes in early stages in shich pretreatment with MMS cause lesions which prevent the reproduction of the cells. Also big spots were observed which presence is due to recombination. It was detected than the bigger the concentration of MMS and radiation dose, the bigger the induced damage. In some groups such observation was impossible may be to technical problems as relative humidity, out of phase in the growth of larvaes giving place that treatment were given in three stages. For this reasons it was impossible to discriminate if drosophila melanogaster is wheter or not capable to induce a repair mechanism (Author)
Low-resolution structure of Drosophila translin

Science.gov (United States)

Kumar, Vinay; Gupta, Gagan D.

2012-01-01

Crystals of native Drosophila melanogaster translin diffracted to 7 Å resolution. Reductive methylation of the protein improved crystal quality. The native and methylated proteins showed similar profiles in size-exclusion chromatography analyses but the methylated protein displayed reduced DNA-binding activity. Crystals of the methylated protein diffracted to 4.2 Å resolution at BM14 of the ESRF synchrotron. Crystals with 49% solvent content belonged to monoclinic space group P21 with eight protomers in the asymmetric unit. Only 2% of low-resolution structures with similar low percentage solvent content were found in the PDB. The crystal structure, solved by molecular replacement method, refined to Rwork (Rfree) of 0.24 (0.29) with excellent stereochemistry. The crystal structure clearly shows that drosophila protein exists as an octamer, and not as a decamer as expected from gel-filtration elution profiles. The similar octameric quaternary fold in translin orthologs and in translin–TRAX complexes suggests an up-down dimer as the basic structural subunit of translin-like proteins. The drosophila oligomer displays asymmetric assembly and increased radius of gyration that accounts for the observed differences between the elution profiles of human and drosophila proteins on gel-filtration columns. This study demonstrates clearly that low-resolution X-ray structure can be useful in understanding complex biological oligomers. PMID:23650579
The Drosophila KIF1A homolog unc-104 is important for site-specific active zone maturation

Directory of Open Access Journals (Sweden)

Yao V. Zhang

2016-09-01

Full Text Available Abstract Mutations in the kinesin-3 family member KIF1A have been associated with hereditary spastic paraplegia, hereditary sensory and autonomic neuropathy type 2 and intellectual disability. Both autosomal recessive and autosomal dominant forms of inheritance have been reported. Loss of KIF1A or its homolog unc-104 causes early postnatal or embryonic lethality in mice and Drosophila, respectively. In this study we use a previously described hypomorphic allele of unc-104, unc-104bris, to investigate the impact of partial loss-of-function of kinesin-3 function on active zone formation at the Drosophila neuromuscular junction. unc-104bris mutants exhibit synaptic defects where a subset of synapses at the neuromuscular junction lack the key active zone organizer protein Bruchpilot. Modulating synaptic Bruchpilot levels by ectopic overexpression or RNAi-mediated knockdown suggests that the loss of active zone components such as Ca2+ channel and Liprin-α from these synapses is caused by impaired kinesin-3 transport rather than due to the absence of Bruchpilot at these synapses. In addition to defects in active zone maturation, unc-104bris mutants display impaired transport of dense core vesicles and synaptic vesicle associated proteins, among which Rab3 has been shown to regulate the distribution of Bruchpilot to active zones. Overexpression of Rab3 partially ameliorates synaptic phenotypes of unc-104bris neuromuscular junction, suggesting that lack of presynaptic Rab3 may contribute to defects in synapse maturation.
Microtubules are organized independently of the centrosome in Drosophila neurons

Directory of Open Access Journals (Sweden)

Nguyen Michelle M

2011-12-01

Full Text Available Abstract Background The best-studied arrangement of microtubules is that organized by the centrosome, a cloud of microtubule nucleating and anchoring proteins is clustered around centrioles. However, noncentrosomal microtubule arrays are common in many differentiated cells, including neurons. Although microtubules are not anchored at neuronal centrosomes, it remains unclear whether the centrosome plays a role in organizing neuronal microtubules. We use Drosophila as a model system to determine whether centrosomal microtubule nucleation is important in mature neurons. Results In developing and mature neurons, centrioles were not surrounded by the core nucleation protein γ-tubulin. This suggests that the centrioles do not organize functional centrosomes in Drosophila neurons in vivo. Consistent with this idea, centriole position was not correlated with a specific region of the cell body in neurons, and growing microtubules did not cluster around the centriole, even after axon severing when the number of growing plus ends is dramatically increased. To determine whether the centrosome was required for microtubule organization in mature neurons, we used two approaches. First, we used DSas-4 centriole duplication mutants. In these mutants, centrioles were present in many larval sensory neurons, but they were not fully functional. Despite reduced centriole function, microtubule orientation was normal in axons and dendrites. Second, we used laser ablation to eliminate the centriole, and again found that microtubule polarity in axons and dendrites was normal, even 3 days after treatment. Conclusion We conclude that the centrosome is not a major site of microtubule nucleation in Drosophila neurons, and is not required for maintenance of neuronal microtubule organization in these cells.

A novel assay reveals hygrotactic behavior in Drosophila.

Directory of Open Access Journals (Sweden)

Feiteng Ji

Full Text Available Humidity is one of the most important factors that determines the geographical distribution and survival of terrestrial animals. The ability to detect variation in humidity is conserved across many species. Here, we established a novel behavioral assay that revealed the thirsty Drosophila exhibits strong hygrotactic behavior, and it can locate water by detecting humidity gradient. In addition, exposure to high levels of moisture was sufficient to elicit proboscis extension reflex behavior in thirsty flies. Furthermore, we found that the third antennal segment was necessary for hygrotactic behavior in thirsty flies, while arista was required for the avoidance of moist air in hydrated flies. These results indicated that two types of hygroreceptor cells exist in Drosophila: one located in the third antennal segment that mediates hygrotactic behavior in thirst status, and the other located in arista which is responsible for the aversive behavior toward moist air in hydration status. Using a neural silencing screen, we demonstrated that synaptic output from the mushroom body α/β surface and posterior neurons was required for both hygrotactic behavior and moisture-aversive behavior.
Cyclin G Functions as a Positive Regulator of Growth and Metabolism in Drosophila.

Directory of Open Access Journals (Sweden)

Patrick Fischer

2015-08-01

Full Text Available In multicellular organisms, growth and proliferation is adjusted to nutritional conditions by a complex signaling network. The Insulin receptor/target of rapamycin (InR/TOR signaling cascade plays a pivotal role in nutrient dependent growth regulation in Drosophila and mammals alike. Here we identify Cyclin G (CycG as a regulator of growth and metabolism in Drosophila. CycG mutants have a reduced body size and weight and show signs of starvation accompanied by a disturbed fat metabolism. InR/TOR signaling activity is impaired in cycG mutants, combined with a reduced phosphorylation status of the kinase Akt1 and the downstream factors S6-kinase and eukaryotic translation initiation factor 4E binding protein (4E-BP. Moreover, the expression and accumulation of Drosophila insulin like peptides (dILPs is disturbed in cycG mutant brains. Using a reporter assay, we show that the activity of one of the first effectors of InR signaling, Phosphoinositide 3-kinase (PI3K92E, is unaffected in cycG mutants. However, the metabolic defects and weight loss in cycG mutants were rescued by overexpression of Akt1 specifically in the fat body and by mutants in widerborst (wdb, the B'-subunit of the phosphatase PP2A, known to downregulate Akt1 by dephosphorylation. Together, our data suggest that CycG acts at the level of Akt1 to regulate growth and metabolism via PP2A in Drosophila.
The Impact of Odor--Reward Memory on Chemotaxis in Larval "Drosophila"

Science.gov (United States)

Schleyer, Michael; Reid, Samuel F.; Pamir, Evren; Saumweber, Timo; Paisios, Emmanouil; Davies, Alexander; Gerber, Bertram; Louis, Matthieu

2015-01-01

How do animals adaptively integrate innate with learned behavioral tendencies? We tackle this question using chemotaxis as a paradigm. Chemotaxis in the "Drosophila" larva largely results from a sequence of runs and oriented turns. Thus, the larvae minimally need to determine (i) how fast to run, (ii) when to initiate a turn, and (iii)…
Generation of genome-modified Drosophila cell lines using SwAP.

Science.gov (United States)

Franz, Alexandra; Brunner, Erich; Basler, Konrad

2017-10-02

The ease of generating genetically modified animals and cell lines has been markedly increased by the recent development of the versatile CRISPR/Cas9 tool. However, while the isolation of isogenic cell populations is usually straightforward for mammalian cell lines, the generation of clonal Drosophila cell lines has remained a longstanding challenge, hampered by the difficulty of getting Drosophila cells to grow at low densities. Here, we describe a highly efficient workflow to generate clonal Cas9-engineered Drosophila cell lines using a combination of cell pools, limiting dilution in conditioned medium and PCR with allele-specific primers, enabling the efficient selection of a clonal cell line with a suitable mutation profile. We validate the protocol by documenting the isolation, selection and verification of eight independently Cas9-edited armadillo mutant Drosophila cell lines. Our method provides a powerful and simple workflow that improves the utility of Drosophila cells for genetic studies with CRISPR/Cas9.
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...
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
Metabolism of methoxychlor by the P450-monooxygenase CYP6G1 involved in insecticide resistance of Drosophila melanogaster after expression in cell cultures of Nicotiana tabacum.

Science.gov (United States)

Joussen, Nicole; Schuphan, Ingolf; Schmidt, Burkhard

2010-03-01

Cytochrome P450 monooxygenase CYP6G1 of Drosophila melanogaster was heterologously expressed in a cell suspension culture of Nicotiana tabacum. This in vitro system was used to study the capability of CYP6G1 to metabolize the insecticide methoxychlor (=1,1,1-trichloro-2,2-bis(4-methoxyphenyl)ethane, 1) against the background of endogenous enzymes of the corresponding non-transgenic culture. The Cyp6g1-transgenic cell culture metabolized 96% of applied methoxychlor (45.8 microg per assay) within 24 h by demethylation and hydroxylation mainly to trishydroxy and catechol methoxychlor (16 and 17%, resp.). About 34% of the metabolism and the distinct formation of trishydroxy and catechol methoxychlor were due to foreign enzyme CYP6G1. Furthermore, methoxychlor metabolism was inhibited by 43% after simultaneous addition of piperonyl butoxide (458 microg), whereas inhibition in the non-transgenic culture amounted to 92%. Additionally, the rate of glycosylation was reduced in both cultures. These results were supported by the inhibition of the metabolism of the insecticide imidacloprid (6; 20 microg, 24 h) in the Cyp6g1-transgenic culture by 82% in the presence of piperonyl butoxide (200 microg). Due to CYP6G1 being responsible for imidacloprid resistance of Drosophila or being involved in DDT resistance, it is likely that CYP6G1 conveys resistance to methoxychlor (1). Furthermore, treating Drosophila with piperonyl butoxide could weaken the observed resistance phenomena.
A Model of Oxidative Stress Management: Moderation of Carbohydrate Metabolizing Enzymes in SOD1-Null Drosophila melanogaster

Science.gov (United States)

Bernard, Kristine E.; Parkes, Tony L.; Merritt, Thomas J. S.

2011-01-01

The response to oxidative stress involves numerous genes and mutations in these genes often manifest in pleiotropic ways that presumably reflect perturbations in ROS-mediated physiology. The Drosophila melanogaster SOD1-null allele (cSODn108) is proposed to result in oxidative stress by preventing superoxide breakdown. In SOD1-null flies, oxidative stress management is thought to be reliant on the glutathione-dependent antioxidants that utilize NADPH to cycle between reduced and oxidized form. Previous studies suggest that SOD1-null Drosophila rely on lipid catabolism for energy rather than carbohydrate metabolism. We tested these connections by comparing the activity of carbohydrate metabolizing enzymes, lipid and triglyceride concentration, and steady state NADPH:NADP+ in SOD1-null and control transgenic rescue flies. We find a negative shift in the activity of carbohydrate metabolizing enzymes in SOD1-nulls and the NADP+-reducing enzymes were found to have significantly lower activity than the other enzymes assayed. Little evidence for the catabolism of lipids as preferential energy source was found, as the concentration of lipids and triglycerides were not significantly lower in SOD1-nulls compared with controls. Using a starvation assay to impact lipids and triglycerides, we found that lipids were indeed depleted in both genotypes when under starvation stress, suggesting that oxidative damage was not preventing the catabolism of lipids in SOD1-null flies. Remarkably, SOD1-nulls were also found to be relatively resistant to starvation. Age profiles of enzyme activity, triglyceride and lipid concentration indicates that the trends observed are consistent over the average lifespan of the SOD1-nulls. Based on our results, we propose a model of physiological response in which organisms under oxidative stress limit the production of ROS through the down-regulation of carbohydrate metabolism in order to moderate the products exiting the electron transport chain. PMID
Research progress on Drosophila visual cognition in China

Institute of Scientific and Technical Information of China (English)

无

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.
Research progress on Drosophila visual cognition in China.

Science.gov (United States)

Guo, AiKe; Zhang, Ke; Peng, YueQin; Xi, Wang

2010-03-01

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.
Diet-induced mating preference in Drosophila

OpenAIRE

Rosenberg, Eugene; Zilber-Rosenberg, Ilana; Sharon, Gil; Segal, Daniel

2018-01-01

Diet-induced mating preference was initially observed by Dodd (1). Subsequently, we reported that diet-induced mating preference occurred in Drosophila melanogaster. Treatment of the flies with antibiotics abolished the mating preference, suggesting that fly-associated commensal bacteria were responsible for the phenomenon (2). The hypothesis was confirmed when it was shown that colonizing antibiotic-treated flies with Lactobacillus plantarum reestablished mating preference in multiple-choice...
Strain-specific and pooled genome sequences for populations of Drosophila melanogaster from three continents.

Science.gov (United States)

Bergman, Casey M; Haddrill, Penelope R

2015-01-01

To contribute to our general understanding of the evolutionary forces that shape variation in genome sequences in nature, we have sequenced genomes from 50 isofemale lines and six pooled samples from populations of Drosophila melanogaster on three continents. Analysis of raw and reference-mapped reads indicates the quality of these genomic sequence data is very high. Comparison of the predicted and experimentally-determined Wolbachia infection status of these samples suggests that strain or sample swaps are unlikely to have occurred in the generation of these data. Genome sequences are freely available in the European Nucleotide Archive under accession ERP009059. Isofemale lines can be obtained from the Drosophila Species Stock Center.
Functional requirements driving the gene duplication in 12 Drosophila species.

Science.gov (United States)

Zhong, Yan; Jia, Yanxiao; Gao, Yang; Tian, Dacheng; Yang, Sihai; Zhang, Xiaohui

2013-08-15

Gene duplication supplies the raw materials for novel gene functions and many gene families arisen from duplication experience adaptive evolution. Most studies of young duplicates have focused on mammals, especially humans, whereas reports describing their genome-wide evolutionary patterns across the closely related Drosophila species are rare. The sequenced 12 Drosophila genomes provide the opportunity to address this issue. In our study, 3,647 young duplicate gene families were identified across the 12 Drosophila species and three types of expansions, species-specific, lineage-specific and complex expansions, were detected in these gene families. Our data showed that the species-specific young duplicate genes predominated (86.6%) over the other two types. Interestingly, many independent species-specific expansions in the same gene family have been observed in many species, even including 11 or 12 Drosophila species. Our data also showed that the functional bias observed in these young duplicate genes was mainly related to responses to environmental stimuli and biotic stresses. This study reveals the evolutionary patterns of young duplicates across 12 Drosophila species on a genomic scale. Our results suggest that convergent evolution acts on young duplicate genes after the species differentiation and adaptive evolution may play an important role in duplicate genes for adaption to ecological factors and environmental changes in Drosophila.
Drosophila melanogaster cellular repressor of E1A-stimulated genes is a lysosomal protein essential for fly development

OpenAIRE

Kowalewski-Nimmerfall, Elisabeth; Sch?hs, Philipp; Maresch, Daniel; Rendic, Dubravko; Kr?mer, Helmut; Mach, Lukas

2014-01-01

Mammalian cellular repressor of E1A-stimulated genes is a lysosomal glycoprotein implicated in cellular growth and differentiation. The genome of the fruit fly Drosophila melanogaster encodes a putative orthologue (dCREG), suggesting evolutionarily conserved physiological functions of this protein. In D. melanogaster S2 cells, dCREG was found to localize in lysosomes. Further studies revealed that intracellular dCREG is subject of proteolytic maturation. Processing and turnover could be subst...
Centriole Remodeling during Spermiogenesis in Drosophila.

Science.gov (United States)

Khire, Atul; Jo, Kyoung H; Kong, Dong; Akhshi, Tara; Blachon, Stephanie; Cekic, Anthony R; Hynek, Sarah; Ha, Andrew; Loncarek, Jadranka; Mennella, Vito; Avidor-Reiss, Tomer

2016-12-05

The first cell of an animal (zygote) requires centrosomes that are assembled from paternally inherited centrioles and maternally inherited pericentriolar material (PCM) [1]. In some animals, sperm centrioles with typical ultrastructure are the origin of the first centrosomes in the zygote [2-4]. In other animals, however, sperm centrioles lose their proteins and are thought to be degenerated and non-functional during spermiogenesis [5, 6]. Here, we show that the two sperm centrioles (the giant centriole [GC] and the proximal centriole-like structure [PCL]) in Drosophila melanogaster are remodeled during spermiogenesis through protein enrichment and ultrastructure modification in parallel to previously described centrosomal reduction [7]. We found that the ultrastructure of the matured sperm (spermatozoa) centrioles is modified dramatically and that the PCL does not resemble a typical centriole. We also describe a new phenomenon of Poc1 enrichment of the atypical centrioles in the spermatozoa. Using various mutants, protein expression during spermiogenesis, and RNAi knockdown of paternal Poc1, we found that paternal Poc1 enrichment is essential for the formation of centrioles during spermiogenesis and for the formation of centrosomes after fertilization in the zygote. Altogether, these findings demonstrate that the sperm centrioles are remodeled both in their protein composition and in ultrastructure, yet they are functional and are essential for normal embryogenesis in Drosophila. Copyright © 2016 Elsevier Ltd. All rights reserved.
U bodies respond to nutrient stress in Drosophila

International Nuclear Information System (INIS)

Buckingham, Mickey; Liu, Ji-Long

2011-01-01

The neurodegenerative disease spinal muscular atrophy (SMA) is caused by mutation of the survival motor neuron 1 (SMN1) gene. Cytoplasmic SMN protein-containing granules, known as U snRNP bodies (U bodies), are thought to be responsible for the assembly and storage of small nuclear ribonucleoproteins (snRNPs) which are essential for pre-mRNA splicing. U bodies exhibit close association with cytoplasmic processing bodies (P bodies), which are involved in mRNA decay and translational repression. The close association of the U body and P body in Drosophila resemble that of the stress granule and P body in yeast and mammalian cells. However, it is unknown whether the U body is responsive to any stress. Using Drosophila oogenesis as a model, here we show that U bodies increase in size following nutritional deprivation. Despite nutritional stress, U bodies maintain their close association with P bodies. Our results show that U bodies are responsive to nutrition changes, presumably through the U body–P body pathway.
U bodies respond to nutrient stress in Drosophila

Energy Technology Data Exchange (ETDEWEB)

Buckingham, Mickey; Liu, Ji-Long, E-mail: jilong.liu@dpag.ox.ac.uk

2011-12-10

The neurodegenerative disease spinal muscular atrophy (SMA) is caused by mutation of the survival motor neuron 1 (SMN1) gene. Cytoplasmic SMN protein-containing granules, known as U snRNP bodies (U bodies), are thought to be responsible for the assembly and storage of small nuclear ribonucleoproteins (snRNPs) which are essential for pre-mRNA splicing. U bodies exhibit close association with cytoplasmic processing bodies (P bodies), which are involved in mRNA decay and translational repression. The close association of the U body and P body in Drosophila resemble that of the stress granule and P body in yeast and mammalian cells. However, it is unknown whether the U body is responsive to any stress. Using Drosophila oogenesis as a model, here we show that U bodies increase in size following nutritional deprivation. Despite nutritional stress, U bodies maintain their close association with P bodies. Our results show that U bodies are responsive to nutrition changes, presumably through the U body-P body pathway.
Determination of Relative Biological Efficacy (RBE) and Oxygen Enhancement Ratio (OER) for the entire negative and positive pion beam profile using Vicia faba roots and Drosophila embryos as biological model systems

International Nuclear Information System (INIS)

Baarli, J.; Bianchi, M.; Keusch, F.; Mindek, G.; Sullivan, A.H.

As an introduction to preclinical studies, pilot studies of pion beams are planned with relatively simple biological model systems that can be quickly evaluated and that yield indicative data for further action. Inhibition of growth was studied in Vicia faba roots, a biological system excellently suited for RBE and OER studies. For comparison there are already results from a low-intensity pion irradiation. A second system used Drosophila embryos 1 and 4 hours old, which are especially well suited for LET studies. The unambiguous criterion will be failure to slip out of the oolemma. The smallness of the objects (their beam sensitivity) will make it possible to determine empirically the peak region and to determine Gain factors; furthermore, the known dependency of RBE on the development stage promises highly informative results
Polymorphism patterns in two tightly linked developmental genes, Idgf1 and Idgf3, of Drosophila melanogaster

Czech Academy of Sciences Publication Activity Database

Žurovcová, Martina; Ayala, F. J.

2002-01-01

Roč. 162, - (2002), s. 177-188 ISSN 0016-6731 Institutional research plan: CEZ:AV0Z5007907 Keywords : Drosophila melanogaster Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.483, year: 2002
Wiring economy and volume exclusion determine neuronal placement in the Drosophila brain.

Science.gov (United States)

Rivera-Alba, Marta; Vitaladevuni, Shiv N; Mishchenko, Yuriy; Mischenko, Yuriy; Lu, Zhiyuan; Takemura, Shin-Ya; Scheffer, Lou; Meinertzhagen, Ian A; Chklovskii, Dmitri B; de Polavieja, Gonzalo G

2011-12-06

Wiring economy has successfully explained the individual placement of neurons in simple nervous systems like that of Caenorhabditis elegans [1-3] and the locations of coarser structures like cortical areas in complex vertebrate brains [4]. However, it remains unclear whether wiring economy can explain the placement of individual neurons in brains larger than that of C. elegans. Indeed, given the greater number of neuronal interconnections in larger brains, simply minimizing the length of connections results in unrealistic configurations, with multiple neurons occupying the same position in space. Avoiding such configurations, or volume exclusion, repels neurons from each other, thus counteracting wiring economy. Here we test whether wiring economy together with volume exclusion can explain the placement of neurons in a module of the Drosophila melanogaster brain known as lamina cartridge [5-13]. We used newly developed techniques for semiautomated reconstruction from serial electron microscopy (EM) [14] to obtain the shapes of neurons, the location of synapses, and the resultant synaptic connectivity. We show that wiring length minimization and volume exclusion together can explain the structure of the lamina microcircuit. Therefore, even in brains larger than that of C. elegans, at least for some circuits, optimization can play an important role in individual neuron placement. Copyright © 2011 Elsevier Ltd. All rights reserved.

New Dystrophin/Dystroglycan interactors control neuron behavior in Drosophila eye

Directory of Open Access Journals (Sweden)

Rishko Valentyna M

2011-09-01

Full Text Available Abstract Background The Dystrophin Glycoprotein Complex (DGC is a large multi-component complex that is well known for its function in muscle tissue. When the main components of the DGC, Dystrophin (Dys and Dystroglycan (Dg are affected cognitive impairment and mental retardation in addition to muscle degeneration can occur. Previously we performed an array of genetic screens using a Drosophila model for muscular dystrophy in order to find novel DGC interactors aiming to elucidate the signaling role(s in which the complex is involved. Since the function of the DGC in the brain and nervous system has not been fully defined, we have here continued to analyze the DGC modifiers' function in the developing Drosophila brain and eye. Results Given that disruption of Dys and Dg leads to improper photoreceptor axon projections into the lamina and eye neuron elongation defects during development, we have determined the function of previously screened components and their genetic interaction with the DGC in this tissue. Our study first found that mutations in chif, CG34400, Nrk, Lis1, capt and Cam cause improper axon path-finding and loss of SP2353, Grh, Nrk, capt, CG34400, vimar, Lis1 and Cam cause shortened rhabdomere lengths. We determined that Nrk, mbl, capt and Cam genetically interact with Dys and/or Dg in these processes. It is notable that most of the neuronal DGC interacting components encountered are involved in regulation of actin dynamics. Conclusions Our data indicate possible DGC involvement in the process of cytoskeletal remodeling in neurons. The identification of new components that interact with the DGC not only helps to dissect the mechanism of axon guidance and eye neuron differentiation but also provides a great opportunity for understanding the signaling mechanisms by which the cell surface receptor Dg communicates via Dys with the actin cytoskeleton.
Enhanced tethered-flight duration and locomotor activity by overexpression of the human gene SOD1 in Drosophila motorneurons

Directory of Open Access Journals (Sweden)

Agavni Petrosyan

2015-03-01

Full Text Available Mutation of the human gene superoxide dismutase (hSOD1 is associated with the fatal neurodegenerative disease familial amyotrophic lateral sclerosis (Lou Gehrig’s disease. Selective overexpression of hSOD1 in Drosophila motorneurons increases lifespan to 140% of normal. The current study was designed to determine resistance to lifespan decline and failure of sensorimotor functions by overexpressing hSOD1 in Drosophila‘s motorneurons. First, we measured the ability to maintain continuous flight and wingbeat frequency (WBF as a function of age (5 to 50 days. Flies overexpressing hSOD1 under the D42-GAL4 activator were able to sustain flight significantly longer than controls, with the largest effect observed in the middle stages of life. The hSOD1-expressed line also had, on average, slower wingbeat frequencies in late, but not early life relative to age-matched controls. Second, we examined locomotor (exploratory walking behavior in late life when flies had lost the ability to fly (age ≥ 60 d. hSOD1-expressed flies showed significantly more robust walking activity relative to controls. Findings show patterns of functional decline dissimilar to those reported for other life-extended lines, and suggest that the hSOD1 gene not only delays death but enhances sensorimotor abilities critical to survival even in late life.
Internucleotide correlations and nucleotide periodicity in Drosophila mtDNA: New evidence for panselective evolution

Directory of Open Access Journals (Sweden)

Carlos Y Valenzuela

2010-01-01

Full Text Available Analysis for the homogeneity of the distribution of the second base of dinucleotides in relation to the first, whose bases are separated by 0, 1, 2,... 21 nucleotide sites, was performed with the VIH-1 genome (cDNA, the Drosophila mtDNA, the Drosophila Torso gene and the human p-globin gene. These four DNA segments showed highly significant heterogeneities of base distributions that cannot be accounted for by neutral or nearly neutral evolution or by the "neighbor influence" of nucleotides on mutation rates. High correlations are found in the bases of dinucleotides separated by 0, 1 and more number of sites. A periodicity of three consecutive significance values (measured by the x²9 was found only in Drosophila mtDNA. This periodicity may be due to an unknown structure or organization of mtDNA. This non-random distribution of the two bases of dinucleotides widespread throughout these DNA segments is rather compatible with panselective evolution and generalized internucleotide co-adaptation.
Adaptation to Variance of Stimuli in Drosophila Larva Navigation

Science.gov (United States)

Wolk, Jason; Gepner, Ruben; Gershow, Marc

In order to respond to stimuli that vary over orders of magnitude while also being capable of sensing very small changes, neural systems must be capable of rapidly adapting to the variance of stimuli. We study this adaptation in Drosophila larvae responding to varying visual signals and optogenetically induced fictitious odors using an infrared illuminated arena and custom computer vision software. Larval navigational decisions (when to turn) are modeled as the output a linear-nonlinear Poisson process. The development of the nonlinear turn rate in response to changes in variance is tracked using an adaptive point process filter determining the rate of adaptation to different stimulus profiles. Supported by NIH Grant 1DP2EB022359 and NSF Grant PHY-1455015.
Human SOD1 ALS Mutations in a Drosophila Knock-In Model Cause Severe Phenotypes and Reveal Dosage-Sensitive Gain- and Loss-of-Function Components.

Science.gov (United States)

Şahin, Aslı; Held, Aaron; Bredvik, Kirsten; Major, Paxton; Achilli, Toni-Marie; Kerson, Abigail G; Wharton, Kristi; Stilwell, Geoff; Reenan, Robert

2017-02-01

Amyotrophic Lateral Sclerosis (ALS) is the most common adult-onset motor neuron disease and familial forms can be caused by numerous dominant mutations of the copper-zinc superoxide dismutase 1 (SOD1) gene. Substantial efforts have been invested in studying SOD1-ALS transgenic animal models; yet, the molecular mechanisms by which ALS-mutant SOD1 protein acquires toxicity are not well understood. ALS-like phenotypes in animal models are highly dependent on transgene dosage. Thus, issues of whether the ALS-like phenotypes of these models stem from overexpression of mutant alleles or from aspects of the SOD1 mutation itself are not easily deconvolved. To address concerns about levels of mutant SOD1 in disease pathogenesis, we have genetically engineered four human ALS-causing SOD1 point mutations (G37R, H48R, H71Y, and G85R) into the endogenous locus of Drosophila SOD1 (dsod) via ends-out homologous recombination and analyzed the resulting molecular, biochemical, and behavioral phenotypes. Contrary to previous transgenic models, we have recapitulated ALS-like phenotypes without overexpression of the mutant protein. Drosophila carrying homozygous mutations rendering SOD1 protein enzymatically inactive (G85R, H48R, and H71Y) exhibited neurodegeneration, locomotor deficits, and shortened life span. The mutation retaining enzymatic activity (G37R) was phenotypically indistinguishable from controls. While the observed mutant dsod phenotypes were recessive, a gain-of-function component was uncovered through dosage studies and comparisons with age-matched dsod null animals, which failed to show severe locomotor defects or nerve degeneration. We conclude that the Drosophila knock-in model captures important aspects of human SOD1-based ALS and provides a powerful and useful tool for further genetic studies. Copyright © 2017 by the Genetics Society of America.
Orthodenticle is required for the development of olfactory projection neurons and local interneurons in Drosophila

Directory of Open Access Journals (Sweden)

Sonia Sen

2014-07-01

Full Text Available The accurate wiring of nervous systems involves precise control over cellular processes like cell division, cell fate specification, and targeting of neurons. The nervous system of Drosophila melanogaster is an excellent model to understand these processes. Drosophila neurons are generated by stem cell like precursors called neuroblasts that are formed and specified in a highly stereotypical manner along the neuroectoderm. This stereotypy has been attributed, in part, to the expression and function of transcription factors that act as intrinsic cell fate determinants in the neuroblasts and their progeny during embryogenesis. Here we focus on the lateral neuroblast lineage, ALl1, of the antennal lobe and show that the transcription factor-encoding cephalic gap gene orthodenticle is required in this lineage during postembryonic brain development. We use immunolabelling to demonstrate that Otd is expressed in the neuroblast of this lineage during postembryonic larval stages. Subsequently, we use MARCM clonal mutational methods to show that the majority of the postembryonic neuronal progeny in the ALl1 lineage undergoes apoptosis in the absence of orthodenticle. Moreover, we demonstrate that the neurons that survive in the orthodenticle loss-of-function condition display severe targeting defects in both the proximal (dendritic and distal (axonal neurites. These findings indicate that the cephalic gap gene orthodenticle acts as an important intrinsic determinant in the ALl1 neuroblast lineage and, hence, could be a member of a putative combinatorial code involved in specifying the fate and identity of cells in this lineage.
Thermal phenotypic plasticity of body size in Drosophila ...

Indian Academy of Sciences (India)

... body size in Drosophila melanogaster: sexual dimorphism and genetic correlations. Jean R. David, Amir Yassin, Jean-Claude Moreteau, Helene Legout and Brigitte Moreteau. J. Genet. 90, 295–302. Table 1. Correlations between wing and thorax length at the within (n = 420) and between line level (n = 30). Temperature.
Genome-wide comparative analysis of four Indian Drosophila species.

Science.gov (United States)

Mohanty, Sujata; Khanna, Radhika

2017-12-01

Comparative analysis of multiple genomes of closely or distantly related Drosophila species undoubtedly creates excitement among evolutionary biologists in exploring the genomic changes with an ecology and evolutionary perspective. We present herewith the de novo assembled whole genome sequences of four Drosophila species, D. bipectinata, D. takahashii, D. biarmipes and D. nasuta of Indian origin using Next Generation Sequencing technology on an Illumina platform along with their detailed assembly statistics. The comparative genomics analysis, e.g. gene predictions and annotations, functional and orthogroup analysis of coding sequences and genome wide SNP distribution were performed. The whole genome of Zaprionus indianus of Indian origin published earlier by us and the genome sequences of previously sequenced 12 Drosophila species available in the NCBI database were included in the analysis. The present work is a part of our ongoing genomics project of Indian Drosophila species.
Drosophila increase exploration after visually detecting predators.

Directory of Open Access Journals (Sweden)

Miguel de la Flor

Full Text Available Novel stimuli elicit behaviors that are collectively known as specific exploration. These behaviors allow the animal to become more familiar with the novel objects within its environment. Specific exploration is frequently suppressed by defensive reactions to predator cues. Herein, we examine if this suppression occurs in Drosophila melanogaster by measuring the response of these flies to wild harvested predators. The flies used in our experiments have been cultured and had not lived under predator threat for multiple decades. In a circular arena with centrally-caged predators, wild type Drosophila actively avoided the pantropical jumping spider, Plexippus paykulli, and the Texas unicorn mantis, Phyllovates chlorophaena, indicating an innate defensive reaction to these predators. Interestingly, wild type Drosophila males also avoided a centrally-caged mock spider, and the avoidance of the mock spider became exaggerated when it was made to move within the cage. Visually impaired Drosophila failed to detect and avoid the Plexippus paykulli and the moving mock spider, while the broadly anosmic orco2 mutants were fully capable of detecting and avoiding Plexippus paykulli, indicating that these flies principally relied upon vison to perceive the predator stimuli. During early exploration of the arena, exploratory activity increased in the presence of Plexippus paykulli and the moving mock spider. The elevated activity induced by Plexippus paykulli disappeared after the fly had finished exploring, suggesting the flies were capable of habituating the predator cues. Taken together, these results indicate that despite being isolated from predators for decades Drosophila will visually detect these predators, retain innate defensive behaviors, respond by increasing exploratory activity in the arena rather than suppressing activity, and may habituate to normal predator cues.
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.
High density lipoprotein (HDL)-associated sphingosine 1-phosphate (S1P) inhibits macrophage apoptosis by stimulating STAT3 activity and survivin expression.

Science.gov (United States)

Feuerborn, Renata; Becker, Susen; Potì, Francesco; Nagel, Petra; Brodde, Martin; Schmidt, Harmut; Christoffersen, Christina; Ceglarek, Uta; Burkhardt, Ralph; Nofer, Jerzy-Roch

2017-02-01

Macrophage apoptosis is critically involved in atherosclerosis. We here examined the effect of anti-atherogenic high density lipoprotein (HDL) and its component sphingosine-1-phosphate (S1P) on apoptosis in RAW264.7 murine macrophages. Mitochondrial or endoplasmic reticulum-dependent apoptosis was induced by exposure of macrophages to etoposide or thapsigargin/fukoidan, respectively. Cell death induced by these compounds was inhibited by S1P as inferred from reduced annexin V binding, TUNEL staining, and caspase 3, 9 and 12 activities. S1P induced expression of the inhibitor of apoptosis protein (IAP) family proteins cIAP1, cIAP2 and survivin, but only the inhibitor of survivin expression YM155 and not the cIAP1/2 blocker GDC0152 reversed the inhibitory effect of S1P on apoptosis. Moreover, S1P activated signal transducer and activator of transcription 3 (STAT3) and Janus kinase 2 (JAK2) and the stimulatory effect of S1P on survivin expression and inhibitory effects on apoptosis were attenuated by STAT3 or JAK2 inhibitors, S3I-201 or AG490, respectively. The effects of S1P on STAT3 activation, survivin expression and macrophage apoptosis were emulated by HDL, HDL lipids, and apolipoprotein (apo) M-containing HDL, but not by apoA-I or HDL deprived of S1P or apoM. In addition, JTE013 and CAY10444, S1P receptor 2 and 3 antagonists, respectively, compromised the S1P and HDL capacities to stimulate STAT3 activation and survivin expression, and to inhibit apoptosis. HDL-associated S1P inhibits macrophage apoptosis by stimulating STAT3 activity and survivin expression. The suppression of macrophage apoptosis may represent a novel mechanism utilized by HDL to exert its anti-atherogenic effects. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Spectra of molecular changes induced in DNA of Drosophila spermatozoa by 1-ethyl-1-nitrosourea and X-rays

International Nuclear Information System (INIS)

Batzer, M.A.; Fossett, N.G.; Lee, W.R.; Louisiana State Univ., Baton Rouge; Tedeschi, B.; Tucker, A.; Kilroy, G.; Arbour, P.

1988-01-01

Mutations induced in Drosophila spermatozoa at the alcohol dehydrogenase Adh locus by 1-ethyl-1-nitrosourea (ENU) were compared to X-ray-induced mutations using genetic tests for complementation, southern blotting, western blotting and northern blotting. 8 of 10 ENU-induced mutations complemented all known adjacent loci and were presumed to be intragenic. In contrast, 8 of 30 X-ray-induced mutations were intragenic. The interpretation of these results is that in spermatozoa X-rays induce primarily deletions that either produce deficiencies of the Adh locus or nonsense mutations within the locus, whereas ENU induces primarily missense mutations. This forward mutation assay based on loss of enzymatic activity efficiently recovered a broad spectrum of mutations ranging from missense to intragenic deletions and multi-locus deficiencies. Only 3 of these 40 mutations produced a polypeptide detectable as an electrophoretic variant. 37 refs.; 6 figs.; 2 tabs
Target organ specific activity of drosophila MRP (ABCC1) moderates developmental toxicity of methylmercury.

Science.gov (United States)

Prince, Lisa; Korbas, Malgorzata; Davidson, Philip; Broberg, Karin; Rand, Matthew Dearborn

2014-08-01

Methylmercury (MeHg) is a ubiquitous and persistent neurotoxin that poses a risk to human health. Although the mechanisms of MeHg toxicity are not fully understood, factors that contribute to susceptibility are even less well known. Studies of human gene polymorphisms have identified a potential role for the multidrug resistance-like protein (MRP/ABCC) family, ATP-dependent transporters, in MeHg susceptibility. MRP transporters have been shown to be important for MeHg excretion in adult mouse models, but their role in moderating MeHg toxicity during development has not been explored. We therefore investigated effects of manipulating expression levels of MRP using a Drosophila development assay. Drosophila MRP (dMRP) is homologous to human MRP1-4 (ABCC1-4), sharing 50% identity and 67% similarity with MRP1. A greater susceptibility to MeHg is seen in dMRP mutant flies, demonstrated by reduced rates of eclosion on MeHg-containing food. Furthermore, targeted knockdown of dMRP expression using GAL4>UAS RNAi methods demonstrates a tissue-specific function for dMRP in gut, Malpighian tubules, and the nervous system in moderating developmental susceptibility to MeHg. Using X-ray synchrotron fluorescence imaging, these same tissues were also identified as the highest Hg-accumulating tissues in fly larvae. Moreover, higher levels of Hg are seen in dMRP mutant larvae compared with a control strain fed an equivalent dose of MeHg. In sum, these data demonstrate that dMRP expression, both globally and within Hg-targeted organs, has a profound effect on susceptibility to MeHg in developing flies. Our findings point to a potentially novel and specific role for dMRP in neurons in the protection against MeHg. Finally, this experimental system provides a tractable model to evaluate human polymorphic variants of MRP and other gene variants relevant to genetic studies of mercury-exposed populations. © The Author 2014. Published by Oxford University Press on behalf of the Society of
Erythritol and Lufenuron detrimentally alter age structure of Wild Spotted Wing Drosophila (SWD) Drosophila suzukii (Diptera: Drosophilidae) populations in blueberry and blackberry

Science.gov (United States)

We report on the efficacy of 0.5 M (61,000 ppm) Erythritol (E) in Truvia Baking Blend®, 10 ppm Lufenuron (L), and their combination (LE) to reduce egg and larval densities of wild populations of spotted wing Drosophila, Drosophila suzukii (Matsumura) (SWD) infesting fields of rabbiteye blueberries (...
Drosophila Studies on Autism Spectrum Disorders

Institute of Scientific and Technical Information of China (English)

Yao Tian; Zi Chao Zhang; Junhai Han

2017-01-01

In the past decade,numerous genes associated with autism spectrum disorders (ASDs) have been identified.These genes encode key regulators of synaptogenesis,synaptic function,and synaptic plasticity.Drosophila is a prominent model system for ASD studies to define novel genes linked to ASDs and decipher their molecular roles in synaptogenesis,synaptic function,synaptic plasticity,and neural circuit assembly and consolidation.Here,we review Drosophila studies on ASD genes that regulate synaptogenesis,synaptic function,and synaptic plasticity through modulating chromatin remodeling,transcription,protein synthesis and degradation,cytoskeleton dynamics,and synaptic scaffolding.
NOVEL ASPECTS OF SPOTTED WING DROSOPHILA BIOLOGY AND IMPROVED METHODS OF REARING

Science.gov (United States)

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

Directory of Open Access Journals (Sweden)

Douglas Mark Ruden

2012-05-01

Full Text Available Drosophila melanogaster is an excellent model animal for studying the neurotoxicology of lead. It has been known since ancient Roman times that long-term exposure to low levels of lead results in behavioral abnormalities, such as what is now known as attention deficit hyperactivity disorder (ADHD. Because lead alters mechanisms that underlie developmental neuronal plasticity, chronic exposure of children, even at blood lead levels below the current CDC community action level (10 µg/dl, can result in reduced cognitive ability, increased likelihood of delinquency, behaviors associated with ADHD, changes in activity level, altered sensory function, delayed onset of sexual maturity in girls, and changes in immune function. In order to better understand how lead affects neuronal plasticity, we will describe recent findings from a Drosophila behavioral genetics laboratory, a Drosophila neurophysiology laboratory, and a Drosophila quantitative genetics laboratory who have joined forces to study the effects of lead on the Drosophila nervous system. Studying the effects of lead on Drosophila nervous system development will give us a better understanding of the mechanisms of Pb neurotoxicity in the developing human nervous system.
Drosophila suzukii population response to environment and management strategies

Science.gov (United States)

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

Science.gov (United States)

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

2014-06-15

Modern biological research relies heavily on microscopic imaging. The advanced genetic toolkit of Drosophila makes it possible to label molecular and cellular components with unprecedented level of specificity necessitating the application of the most sophisticated imaging technologies. Imaging in Drosophila spans all scales from single molecules to the entire populations of adult organisms, from electron microscopy to live imaging of developmental processes. As the imaging approaches become more complex and ambitious, there is an increasing need for quantitative, computer-mediated image processing and analysis to make sense of the imagery. Bioimage Informatics is an emerging research field that covers all aspects of biological image analysis from data handling, through processing, to quantitative measurements, analysis and data presentation. Some of the most advanced, large scale projects, combining cutting edge imaging with complex bioimage informatics pipelines, are realized in the Drosophila research community. In this review, we discuss the current research in biological image analysis specifically relevant to the type of systems level image datasets that are uniquely available for the Drosophila model system. We focus on how state-of-the-art computer vision algorithms are impacting the ability of Drosophila researchers to analyze biological systems in space and time. We pay particular attention to how these algorithmic advances from computer science are made usable to practicing biologists through open source platforms and how biologists can themselves participate in their further development. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
P1-10: The Association between Colors and Emotions

OpenAIRE

Yen-Yu Chen; Chih-Hao Lien; Cho-Han Yang; Yi-Jae Jhong; Tsun-Yu Chen; Shiau-Hua Liu

2012-01-01

Wexner (1954 Journal of Applied Psychology 38 432–435) demonstrated colors were associated with specific emotions. Colors have many meanings, such as that red can lead to induce positive or negative emotions (Kaya & Epps, 2011 College Student Journal 38 396–406). This study extends previous findings and aims to investigate two questions, (1) whether colors are associated with the emotions of pictures in IAPS (International Affective Picture System) and (2) whether perceiving IAPS consciously ...

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.
Irradiated cocoa tested in the wing spot assay in Drosophila melanogaster

International Nuclear Information System (INIS)

Zimmering, S.; Olvera, O.; Cruces, M.P.; Pimentel, E.; Arceo, C.; Rosa, M.E. de la; Guzman, J.

1992-01-01

The result of treatment of Drosophila melanogaster with irradiated cocoa as scored in the somatic wing spot test is described. The test has been used previously in the evaluation of irradiated food and has registrated a significantly greater number of positives among chemicals tested than germ line counterparts. Irradiated cocoa has thus far been reported negative in other mutagenicity assays including those employing salmonella and Drosophila germ cells and mammalian cells. The wing spot test as described in Graf et al. was employed. Females of the genotype mwh were mated with flr 3 /TM3; Ser males. (author). 9 refs.; 1 tab
Drosophila Longevity Assurance Conferred by Reduced Insulin Receptor Substrate Chico Partially Requires d4eBP.

Directory of Open Access Journals (Sweden)

Hua Bai

Full Text Available Mutations of the insulin/IGF signaling (IIS pathway extend Drosophila lifespan. Based on genetic epistasis analyses, this longevity assurance is attributed to downstream effects of the FOXO transcription factor. However, as reported FOXO accounts for only a portion of the observed longevity benefit, suggesting there are additional outputs of IIS to mediate aging. One candidate is target of rapamycin complex 1 (TORC1. Reduced TORC1 activity is reported to slow aging, whereas reduced IIS is reported to repress TORC1 activity. The eukaryotic translation initiation factor 4E binding protein (4E-BP is repressed by TORC1, and activated 4E-BP is reported to increase Drosophila lifespan. Here we use genetic epistasis analyses to test whether longevity assurance mutants of chico, the Drosophila insulin receptor substrate homolog, require Drosophila d4eBP to slow aging. In chico heterozygotes, which are robustly long-lived, d4eBP is required but not sufficient to slow aging. Remarkably, d4eBP is not required or sufficient for chico homozygotes to extend longevity. Likewise, chico heterozygote females partially require d4eBP to preserve age-dependent locomotion, and both chico genotypes require d4eBP to improve stress-resistance. Reproduction and most measures of growth affected by either chico genotype are always independent of d4eBP. In females, chico heterozygotes paradoxically produce more rather than less phosphorylated 4E-BP (p4E-BP. Altered IRS function within the IIS pathway of Drosophila appears to have partial, conditional capacity to regulate aging through an unconventional interaction with 4E-BP.
Characterization of the activity of β-galactosidase from Escherichia coli and Drosophila melanogaster in fixed and non-fixed Drosophila tissues

Directory of Open Access Journals (Sweden)

Mizuki Tomizawa

2016-12-01

Full Text Available β-Galactosidase encoded by the Escherichia coli lacZ gene, is widely used as a reporter molecule in molecular biology in a wide variety of animals. β-Galactosidase retains its enzymatic activity in cells or tissues even after fixation and can degrade X-Gal, a frequently used colormetric substrate, producing a blue color. Therefore, it can be used for the activity staining of fixed tissues. However, the enzymatic activity of the β-galactosidase that is ectopically expressed in the non-fixed tissues of animals has not been extensively studied. Here, we report the characterization of β-galactosidase activity in Drosophila tissues with and without fixation in various experimental conditions comparing the activity of two evolutionarily orthologous β-galactosidases derived from the E. coli lacZ and Drosophila melanogaster DmelGal genes. We performed quantitative analysis of the activity staining of larval imaginal discs and an in vitro assay using larval lysates. Our data showed that both E. coli and Drosophila β-galactosidase can be used for cell-type-specific activity staining, but they have their own preferences in regard to conditions. E. coli β-galactosidase showed a preference for neutral pH but not for acidic pH compared with Drosophila β-galactosidase. Our data suggested that both E. coli and Drosophila β-galactosidase show enzymatic activity in the physiological conditions of living animals when they are ectopically expressed in a desired specific spatial and temporal pattern. This may enable their future application to studies of chemical biology using model animals.
Mutants dissecting development and behaviour in drosophila

International Nuclear Information System (INIS)

Joshi, Adita; Chandrashekaran, Shanti; Sharma, R.P.

2005-01-01

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
Spontaneous alternation: A potential gateway to spatial working memory in Drosophila.

Science.gov (United States)

Lewis, Sara A; Negelspach, David C; Kaladchibachi, Sevag; Cowen, Stephen L; Fernandez, Fabian

2017-07-01

Despite their ubiquity in biomedical research, Drosophila have yet to be widely employed as model organisms in psychology. Many complex human-like behaviors are observed in Drosophila, which exhibit elaborate displays of inter-male aggression and female courtship, self-medication with alcohol in response to stress, and even cultural transmission of social information. Here, we asked whether Drosophila can demonstrate behavioral indices of spatial working memory in a Y-maze, a classic test of memory function and novelty-seeking in rodents. Our data show that Drosophila, like rodents, alternate their visits among the three arms of a Y-maze and spontaneously favor entry into arms they have explored less recently versus ones they have just seen. These findings suggest that Drosophila possess some of the information-seeking and working memory facilities mammals depend on to navigate through space and might be relevant models for understanding human psychological phenomena such as curiosity. Copyright © 2017 Elsevier Inc. All rights reserved.
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

2016-07-30

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.
Mapping of gene mutations in drosophila melanogaster

OpenAIRE

Halvorsen, Charlotte Marie

2004-01-01

In this experiment, mutant genes of a given unknown mutant strain of Drosophila melanogaster were mapped to specific chromosomes. Drosophila melanogaster, commonly known as the fruit fly, was the appropriate choice for the organism to use in this specific experiment because of its relatively rapid life cycle of 10-14 days and because of the small amount of space and food neccessary for maintaining thousands of flies. The D. Melanogaster unknown strain specifically used in this experiment wa...
First foreign exploration for asian parasitoids of Drosophila suzukii

Science.gov (United States)

The invasive spotted wing drosophila, Drosophila suzukii Matsumura (Dipt.: Drosophilidae), is a native of East Asia and is now widely established in North America and Europe, where it is a serious pest of small and stone fruit crops. The lack of effective indigenous parasitoids of D. suzukii in the ...
The X-linked 1.688 Satellite in Drosophila melanogaster Promotes Specific Targeting by Painting of Fourth.

Science.gov (United States)

Kim, Maria; Ekhteraei-Tousi, Samaneh; Lewerentz, Jacob; Larsson, Jan

2018-02-01

Repetitive DNA, represented by transposons and satellite DNA, constitutes a large portion of eukaryotic genomes, being the major component of constitutive heterochromatin. There is a growing body of evidence that it regulates several nuclear functions including chromatin state and the proper functioning of centromeres and telomeres. The 1.688 satellite is one of the most abundant repetitive sequences in Drosophila melanogaster , with the longest array being located in the pericentromeric region of the X-chromosome. Short arrays of 1.688 repeats are widespread within the euchromatic part of the X-chromosome, and these arrays were recently suggested to assist in recognition of the X-chromosome by the dosage compensation male-specific lethal complex. We discovered that a short array of 1.688 satellite repeats is essential for recruitment of the protein POF to a previously described site on the X-chromosome ( PoX2 ) and to various transgenic constructs. On an isolated target, i.e. , an autosomic transgene consisting of a gene upstream of 1.688 satellite repeats, POF is recruited to the transgene in both males and females. The sequence of the satellite, as well as its length and position within the recruitment element, are the major determinants of targeting. Moreover, the 1.688 array promotes POF targeting to the roX1 -proximal PoX1 site in trans Finally, binding of POF to the 1.688-related satellite-enriched sequences is conserved in evolution. We hypothesize that the 1.688 satellite functioned in an ancient dosage compensation system involving POF targeting to the X-chromosome. Copyright © 2018 by the Genetics Society of America.
Capacitación turística en comunidades indígenas. Un caso de Investigación Acción Participativa (IAP

Directory of Open Access Journals (Sweden)

Mariajosé Pastor-Alfonso

2015-01-01

Full Text Available La literatura académica subraya la importancia de involucrar a la comunidad en los procesos de capacitación turística. Sin embargo, apenas hay reflexiones sobre cómo diseñar e implementar la formación en áreas rurales y remotas. En este trabajo se exponen las cuatro fases de un ciclo de Investigación Acción Participativa (IAP, desarrollada en la Selva Lacandona de México con la colaboración de los grupos originarios lacandones y ch’oles. El objetivo de estudio fue la capacitación humana en las áreas de sistemas turísticos, interpretación del patrimonio natural y cultural, y creación de producto. Todo ello complementado con una capacitación específica para mujeres y jóvenes, grupos tradicionalmente relegados en estas comunidades. El relato de las distintas fases de la IAP nos muestra cómo el conocimiento ancestral es la base para una capacitación turística sólida. La involucración de jóvenes estudiantes en los procesos de formación en comunidades, los formatos adaptados a los contextos locales, y los ejercicios de reciprocidad científica, sirven además para la revitalización cultural, el refuerzo de la autoestima y el desarrollo endógeno de los pueblos indígenas.
Genome-wide analysis of promoter architecture in Drosophila melanogaster

Energy Technology Data Exchange (ETDEWEB)

Hoskins, Roger A.; Landolin, Jane M.; Brown, James B.; Sandler, Jeremy E.; Takahashi, Hazuki; Lassmann, Timo; Yu, Charles; Booth, Benjamin W.; Zhang, Dayu; Wan, Kenneth H.; Yang, Li; Boley, Nathan; Andrews, Justen; Kaufman, Thomas C.; Graveley, Brenton R.; Bickel, Peter J.; Carninci, Piero; Carlson, Joseph W.; Celniker, Susan E.

2010-10-20

Core promoters are critical regions for gene regulation in higher eukaryotes. However, the boundaries of promoter regions, the relative rates of initiation at the transcription start sites (TSSs) distributed within them, and the functional significance of promoter architecture remain poorly understood. We produced a high-resolution map of promoters active in the Drosophila melanogaster embryo by integrating data from three independent and complementary methods: 21 million cap analysis of gene expression (CAGE) tags, 1.2 million RNA ligase mediated rapid amplification of cDNA ends (RLMRACE) reads, and 50,000 cap-trapped expressed sequence tags (ESTs). We defined 12,454 promoters of 8037 genes. Our analysis indicates that, due to non-promoter-associated RNA background signal, previous studies have likely overestimated the number of promoter-associated CAGE clusters by fivefold. We show that TSS distributions form a complex continuum of shapes, and that promoters active in the embryo and adult have highly similar shapes in 95% of cases. This suggests that these distributions are generally determined by static elements such as local DNA sequence and are not modulated by dynamic signals such as histone modifications. Transcription factor binding motifs are differentially enriched as a function of promoter shape, and peaked promoter shape is correlated with both temporal and spatial regulation of gene expression. Our results contribute to the emerging view that core promoters are functionally diverse and control patterning of gene expression in Drosophila and mammals.
Drosophila: Retrotransposons Making up Telomeres.

Science.gov (United States)

Casacuberta, Elena

2017-07-19

Drosophila and extant species are the best-studied telomerase exception. In this organism, telomere elongation is coupled with targeted retrotransposition of Healing Transposon (HeT-A) and Telomere Associated Retrotransposon (TART) with sporadic additions of Telomere Associated and HeT-A Related (TAHRE), all three specialized non-Long Terminal Repeat (non-LTR) retrotransposons. These three very special retroelements transpose in head to tail arrays, always in the same orientation at the end of the chromosomes but never in interior locations. Apparently, retrotransposon and telomerase telomeres might seem very different, but a detailed view of their mechanisms reveals similarities explaining how the loss of telomerase in a Drosophila ancestor could successfully have been replaced by the telomere retrotransposons. In this review, we will discover that although HeT-A, TART, and TAHRE are still the only examples to date where their targeted transposition is perfectly tamed into the telomere biology of Drosophila, there are other examples of retrotransposons that manage to successfully integrate inside and at the end of telomeres. Because the aim of this special issue is viral integration at telomeres, understanding the base of the telomerase exceptions will help to obtain clues on similar strategies that mobile elements and viruses could have acquired in order to ensure their survival in the host genome.
Modeling glial contributions to seizures and epileptogenesis: cation-chloride cotransporters in Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Zeid M Rusan

Full Text Available Flies carrying a kcc loss-of-function mutation are more seizure-susceptible than wild-type flies. The kcc gene is the highly conserved Drosophila melanogaster ortholog of K+/Cl- cotransporter genes thought to be expressed in all animal cell types. Here, we examined the spatial and temporal requirements for kcc loss-of-function to modify seizure-susceptibility in flies. Targeted RNA interference (RNAi of kcc in various sets of neurons was sufficient to induce severe seizure-sensitivity. Interestingly, kcc RNAi in glia was particularly effective in causing seizure-sensitivity. Knockdown of kcc in glia or neurons during development caused a reduction in seizure induction threshold, cell swelling, and brain volume increase in 24-48 hour old adult flies. Third instar larval peripheral nerves were enlarged when kcc RNAi was expressed in neurons or glia. Results suggest that a threshold of K+/Cl- cotransport dysfunction in the nervous system during development is an important determinant of seizure-susceptibility in Drosophila. The findings presented are the first attributing a causative role for glial cation-chloride cotransporters in seizures and epileptogenesis. The importance of elucidating glial cell contributions to seizure disorders and the utility of Drosophila models is discussed.
Mutational analysis and genetic cloning of the agnostic locus, which regulates learning ability in Drosophila.

Science.gov (United States)

Peresleni, A I; Savvateeva, E V; Peresleni, I V; Sharagina, L M

1997-01-01

P-insertion mutations were obtained and localized by in situ methods at the agnostic gene (agn: 1-38.9; 11AB) in Drosophila. All agn mutants showed a wide spectrum of pleiotropic effects: an EMS-induced mutation of the agn-ts398 improved the ability to develop a conditioned defensive response and increased the activity of cAMP metabolic enzymes; spontaneous mutation of agnX1 showed morphological defects of the brain. P-insertion mutations were used to clone the gene; a restriction map of 80 kb in length was determined, and the insertion was localized to a fragment of 9 kb.
Drosophila comet assay: insights, uses, and future perspectives

Science.gov (United States)

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 been used to analyze the genotoxicity and action mechanisms of different chemicals, demonstrating good sensitivity and proving its usefulness. Moreover, it is the only assay that can be used to analyze DNA repair in somatic cells in vivo, comparing the effects of chemicals in different repair strains, and to quantitate repair activities in vitro. Additionally, the comet assay in Drosophila, in vivo and in vitro, has been applied to study the influence of protein overexpression on genome integrity and degradation. Although the assay is well established, it could benefit from some research to determine optimal experimental design to standardize it, and then to allow comparisons among laboratories independently of the chosen cell type. PMID:25221574
Genetic human prion disease modelled in PrP transgenic Drosophila.

Science.gov (United States)

Thackray, Alana M; Cardova, Alzbeta; Wolf, Hanna; Pradl, Lydia; Vorberg, Ina; Jackson, Walker S; Bujdoso, Raymond

2017-09-20

Inherited human prion diseases, such as fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD), are associated with autosomal dominant mutations in the human prion protein gene PRNP and accumulation of PrP Sc , an abnormal isomer of the normal host protein PrP C , in the brain of affected individuals. PrP Sc is the principal component of the transmissible neurotoxic prion agent. It is important to identify molecular pathways and cellular processes that regulate prion formation and prion-induced neurotoxicity. This will allow identification of possible therapeutic interventions for individuals with, or at risk from, genetic human prion disease. Increasingly, Drosophila has been used to model human neurodegenerative disease. An important unanswered question is whether genetic prion disease with concomitant spontaneous prion formation can be modelled in Drosophila We have used pUAST/PhiC31-mediated site-directed mutagenesis to generate Drosophila transgenic for murine or hamster PrP (prion protein) that carry single-codon mutations associated with genetic human prion disease. Mouse or hamster PrP harbouring an FFI (D178N) or fCJD (E200K) mutation showed mild Proteinase K resistance when expressed in Drosophila Adult Drosophila transgenic for FFI or fCJD variants of mouse or hamster PrP displayed a spontaneous decline in locomotor ability that increased in severity as the flies aged. Significantly, this mutant PrP-mediated neurotoxic fly phenotype was transferable to recipient Drosophila that expressed the wild-type form of the transgene. Collectively, our novel data are indicative of the spontaneous formation of a PrP-dependent neurotoxic phenotype in FFI- or CJD-PrP transgenic Drosophila and show that inherited human prion disease can be modelled in this invertebrate host. © 2017 The Author(s).
A genomic investigation of ecological differentiation between free-living and Drosophila-associated bacteria.

Science.gov (United States)

Winans, Nathan J; Walter, Alec; Chouaia, Bessem; Chaston, John M; Douglas, Angela E; Newell, Peter D

2017-09-01

Various bacterial taxa have been identified both in association with animals and in the external environment, but the extent to which related bacteria from the two habitat types are ecologically and evolutionarily distinct is largely unknown. This study investigated the scale and pattern of genetic differentiation between bacteria of the family Acetobacteraceae isolated from the guts of Drosophila fruit flies, plant material and industrial fermentations. Genome-scale analysis of the phylogenetic relationships and predicted functions was conducted on 44 Acetobacteraceae isolates, including newly sequenced genomes from 18 isolates from wild and laboratory Drosophila. Isolates from the external environment and Drosophila could not be assigned to distinct phylogenetic groups, nor are their genomes enriched for any different sets of genes or category of predicted gene functions. In contrast, analysis of bacteria from laboratory Drosophila showed they were genetically distinct in their universal capacity to degrade uric acid (a major nitrogenous waste product of Drosophila) and absence of flagellar motility, while these traits vary among wild Drosophila isolates. Analysis of the competitive fitness of Acetobacter discordant for these traits revealed a significant fitness deficit for bacteria that cannot degrade uric acid in culture with Drosophila. We propose that, for wild populations, frequent cycling of Acetobacter between Drosophila and the external environment prevents genetic differentiation by maintaining selection for traits adaptive in both the gut and external habitats. However, laboratory isolates bear the signs of adaptation to persistent association with the Drosophila host under tightly defined environmental conditions. © 2017 John Wiley & Sons Ltd.
Characterization of a method for quantitating food consumption for mutation assays in Drosophila

International Nuclear Information System (INIS)

Thompson, E.D.; Reeder, B.A.; Bruce, R.D.

1991-01-01

Quantitation of food consumption is necessary when determining mutation responses to multiple chemical exposures in the sex-linked recessive lethal assay in Drosophila. One method proposed for quantitating food consumption by Drosophila is to measure the incorporation of 14C-leucine into the flies during the feeding period. Three sources of variation in the technique of Thompson and Reeder have been identified and characterized. First, the amount of food consumed by individual flies differed by almost 30% in a 24 hr feeding period. Second, the variability from vial to vial (each containing multiple flies) was around 15%. Finally, the amount of food consumed in identical feeding experiments performed over the course of 1 year varied nearly 2-fold. The use of chemical consumption values in place of exposure levels provided a better means of expressing the combined mutagenic response. In addition, the kinetics of food consumption over a 3 day feeding period for exposures to cyclophosphamide which produce lethality were compared to non-lethal exposures. Extensive characterization of lethality induced by exposures to cyclophosphamide demonstrate that the lethality is most likely due to starvation, not chemical toxicity
Drosophila melanogaster--the model organism of choice for the complex biology of multi-cellular organisms

Science.gov (United States)

Beckingham, Kathleen M.; Armstrong, J. Douglas; Texada, Michael J.; Munjaal, Ravi; Baker, Dean A.

2005-01-01

Drosophila melanogaster has been intensely studied for almost 100 years. The sophisticated array of genetic and molecular tools that have evolved for analysis of gene function in this organism are unique. Further, Drosophila is a complex multi-cellular organism in which many aspects of development and behavior parallel those in human beings. These combined advantages have permitted research in Drosophila to make seminal contributions to the understanding of fundamental biological processes and ensure that Drosophila will continue to provide unique insights in the genomic era. An overview of the genetic methodologies available in Drosophila is given here, together with examples of outstanding recent contributions of Drosophila to our understanding of cell and organismal biology. The growing contribution of Drosophila to our knowledge of gravity-related responses is addressed.

Crystal structure of the Rasputin NTF2-like domain from Drosophila melanogaster

DEFF Research Database (Denmark)

Vognsen, Tina Reinholdt; Kristensen, Ole

2012-01-01

The crystal structure of the NTF2-like domain of the Drosophila homolog of Ras GTPase SH3 Binding Protein (G3BP), Rasputin, was determined at 2.7Å resolution. The overall structure is highly similar to nuclear transport factor 2: It is a homodimer comprised of a ß-sheet and three a-helices forming...
Inhibitor of Apoptosis (IAP) survivin is indispensable for survival of HER2 gene-amplified breast cancer cells with primary resistance to HER1/2-targeted therapies

International Nuclear Information System (INIS)

Oliveras-Ferraros, Cristina; Vazquez-Martin, Alejandro; Cufi, Silvia; Torres-Garcia, Violeta Zenobia; Sauri-Nadal, Tamara; Barco, Sonia Del; Lopez-Bonet, Eugeni; Brunet, Joan; Martin-Castillo, Begona; Menendez, Javier A.

2011-01-01

Highlights: → Intrinsic trastuzumab resistance occurs in ∼70% of metastatic HER2 + breast carcinomas (BC). → Approximately 15% of early HER2 + BC relapse in spite of treatment with trastuzumab-based therapies. → HER2-independent downstream pro-survival pathways might underlie trastuzumab refractoriness. → Survivin is indispensable for proliferation and survival of HER2 + BC unresponsive to HER2-targeted therapies ab initio. → Survivin antagonists may clinically circumvent the occurrence of de novo resistance to HER2-directed drugs. -- Abstract: Primary resistance of HER2 gene-amplified breast carcinomas (BC) to HER-targeted therapies can be explained in terms of overactive HER2-independent downstream pro-survival pathways. We here confirm that constitutive overexpression of Inhibitor of Apoptosis (IAP) survivin is indispensable for survival of HER2-positive BC cells with intrinsic cross-resistance to multiple HER1/2 inhibitors. The IC 50 values for the HER1/2 Tyrosine Kinase Inhibitors (TKIs) gefitinib, erlotinib and lapatinib were up to 40-fold higher in trastuzumab-unresponsive JIMT-1 cells than in trastuzumab-naive SKBR3 cells. ELISA-based and immunoblotting assays demonstrated that trastuzumab-refractory JIMT-1 cells constitutively expressed ∼4 times more survivin protein than trastuzumab-responsive SKBR3 cells. In response to trastuzumab, JIMT-1 cells accumulated ∼10 times more survivin than SKBR3 cells. HER1/2 TKIs failed to down-regulate survivin expression in JIMT-1 cells whereas equimolar doses of HER1/HER2 TKIs drastically depleted survivin protein in SKBR3 cells. ELISA-based detection of histone-associated DNA fragments confirmed that trastuzumab-refractory JIMT-1 cells were intrinsically protected against the apoptotic effects of HER1/2 TKIs. Of note, when we knocked-down survivin expression using siRNA and then added trastuzumab, cell proliferation and colony formation were completely suppressed in JIMT-1 cells. Our current findings may
Inhibitor of Apoptosis (IAP) survivin is indispensable for survival of HER2 gene-amplified breast cancer cells with primary resistance to HER1/2-targeted therapies

Energy Technology Data Exchange (ETDEWEB)

Oliveras-Ferraros, Cristina; Vazquez-Martin, Alejandro; Cufi, Silvia; Torres-Garcia, Violeta Zenobia [Unit of Translational Research, Catalan Institute of Oncology-Girona, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Girona Biomedical Research Institute, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Sauri-Nadal, Tamara; Barco, Sonia Del [Girona Biomedical Research Institute, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Medical Oncology, Catalan Institute of Oncology-Girona, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Lopez-Bonet, Eugeni [Girona Biomedical Research Institute, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Department of Anatomical Pathology, Dr. Josep Trueta University Hospital, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Brunet, Joan [Girona Biomedical Research Institute, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Medical Oncology, Catalan Institute of Oncology-Girona, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Martin-Castillo, Begona [Girona Biomedical Research Institute, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Unit of Clinical Research, Catalan Institute of Oncology-Girona, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Menendez, Javier A., E-mail: jmenendez@idibgi.org [Unit of Translational Research, Catalan Institute of Oncology-Girona, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain); Girona Biomedical Research Institute, Avenida de Francia S/N, E-17007 Girona, Catalonia (Spain)

2011-04-08

Highlights: {yields} Intrinsic trastuzumab resistance occurs in {approx}70% of metastatic HER2 + breast carcinomas (BC). {yields} Approximately 15% of early HER2 + BC relapse in spite of treatment with trastuzumab-based therapies. {yields} HER2-independent downstream pro-survival pathways might underlie trastuzumab refractoriness. {yields} Survivin is indispensable for proliferation and survival of HER2 + BC unresponsive to HER2-targeted therapies ab initio. {yields} Survivin antagonists may clinically circumvent the occurrence of de novo resistance to HER2-directed drugs. -- Abstract: Primary resistance of HER2 gene-amplified breast carcinomas (BC) to HER-targeted therapies can be explained in terms of overactive HER2-independent downstream pro-survival pathways. We here confirm that constitutive overexpression of Inhibitor of Apoptosis (IAP) survivin is indispensable for survival of HER2-positive BC cells with intrinsic cross-resistance to multiple HER1/2 inhibitors. The IC{sub 50} values for the HER1/2 Tyrosine Kinase Inhibitors (TKIs) gefitinib, erlotinib and lapatinib were up to 40-fold higher in trastuzumab-unresponsive JIMT-1 cells than in trastuzumab-naive SKBR3 cells. ELISA-based and immunoblotting assays demonstrated that trastuzumab-refractory JIMT-1 cells constitutively expressed {approx}4 times more survivin protein than trastuzumab-responsive SKBR3 cells. In response to trastuzumab, JIMT-1 cells accumulated {approx}10 times more survivin than SKBR3 cells. HER1/2 TKIs failed to down-regulate survivin expression in JIMT-1 cells whereas equimolar doses of HER1/HER2 TKIs drastically depleted survivin protein in SKBR3 cells. ELISA-based detection of histone-associated DNA fragments confirmed that trastuzumab-refractory JIMT-1 cells were intrinsically protected against the apoptotic effects of HER1/2 TKIs. Of note, when we knocked-down survivin expression using siRNA and then added trastuzumab, cell proliferation and colony formation were completely
Regulation of sleep by neuropeptide Y-like system in Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Chunxia He

Full Text Available 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 sleep during the nighttime. Further analysis demonstrated that sleep episode duration during nighttime was greatly increased and sleep latency was significantly reduced, indicating that NPF and NPFR1 promote sleep quality, and their action on sleep is not because of an impact of the NPF signal system on development. Moreover, the homeostatic regulation of flies after sleep deprivation was disrupted by altered NPF signaling, since sleep deprivation decreased transcription of NPF in control flies, and there were less sleep loss during sleep deprivation and less sleep gain after sleep deprivation in flies overexpressing NPF and NPFR1 than in control flies, suggesting that NPF system auto-regulation plays an important role in sleep homeostasis. However, these effects did not occur in females, suggesting a sex-dependent regulatory function in sleep for NPF and NPFR1. NPF in D1 brain neurons showed male-specific expression, providing the cellular locus for male-specific regulation of sleep by NPF and NPFR1. This study brings a new understanding into sleep studies of a sexually dimorphic regulatory mode in female and male flies.
Functional variation in the gut microbiome of wild Drosophila populations.

Science.gov (United States)

Bost, Alyssa; Martinson, Vincent G; Franzenburg, Soeren; Adair, Karen L; Albasi, Alice; Wells, Martin T; Douglas, Angela E

2018-05-26

Most of the evidence that the gut microbiome of animals is functionally variable, with consequences for the health and fitness of the animal host, is based on laboratory studies, often using inbred animals under tightly controlled conditions. It is largely unknown whether these microbiome effects would be evident in outbred animal populations under natural conditions. In this study, we quantified the functional traits of the gut microbiota (metagenome) and host (gut transcriptome) and the taxonomic composition of the gut microorganisms (16S rRNA gene sequence) in natural populations of three mycophagous Drosophila species. Variation in microbiome function and composition was driven principally by the period of sample collection, while host function varied mostly with Drosophila species, indicating that variation in microbiome traits is determined largely by environmental factors, and not host taxonomy. Despite this, significant correlations between microbiome and host functional traits were obtained. In particular, microbiome functions dominated by metabolism were positively associated with host functions relating to gut epithelial turnover. Much of the functional variation in the microbiome could be attributed to variation in abundance of Bacteroidetes, rather than the two other abundant groups, the γ-Proteobacteria or Lactobacillales. We conclude that functional variation in the interactions between animals and their gut microbiome can be detectable in natural populations and, in mycophagous Drosophila, this variation relates primarily to metabolism and homeostasis of the gut epithelium. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
The Human dsRNA binding protein PACT is unable to functionally substitute for the Drosophila dsRNA binding protein R2D2 [v1; ref status: indexed, http://f1000r.es/201

Directory of Open Access Journals (Sweden)

Benjamin K Dickerman

2013-10-01

Full Text Available The primary function of the dsRNA binding protein (dsRBP PACT/RAX is to activate the dsRNA dependent protein kinase PKR in response to stress signals. Additionally, it has been identified as a component of the small RNA processing pathway. A role for PACT/RAX in this pathway represents an important interplay between two modes of post-transcriptional gene regulation. The function of PACT/RAX in this context is poorly understood. Thus, additional models are required to clarify the mechanism by which PACT/RAX functions. In this study, Drosophila melanogaster was employed to identify functionally orthologous dsRNA-binding proteins. Transgenic Drosophila expressing human PACT were generated to determine whether PACT is capable of functionally substituting for the Drosophila dsRBP R2D2, which has a well-defined role in small RNA biogenesis. Results presented here indicate that PACT is unable to substitute for R2D2 at the whole organism level.
A genome-wide gene function prediction resource for Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Han Yan

2010-08-01

Full Text Available Predicting gene functions by integrating large-scale biological data remains a challenge for systems biology. Here we present a resource for Drosophila melanogaster gene function predictions. We trained function-specific classifiers to optimize the influence of different biological datasets for each functional category. Our model predicted GO terms and KEGG pathway memberships for Drosophila melanogaster genes with high accuracy, as affirmed by cross-validation, supporting literature evidence, and large-scale RNAi screens. The resulting resource of prioritized associations between Drosophila genes and their potential functions offers a guide for experimental investigations.
Life span extension and neuronal cell protection by Drosophila nicotinamidase.

Science.gov (United States)

Balan, Vitaly; Miller, Gregory S; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; VanBerkum, Mark F A; Arking, Robert; Freeman, D Carl; Maiese, Kenneth; Tzivion, Guri

2008-10-10

The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone deacetylases. In Caenorhabditis elegans, knockdown of a pnc1 homolog was shown recently to shorten the worm life span, whereas its overexpression increased survival under conditions of oxidative stress. The function and regulation of nicotinamidases in higher organisms has not been determined. Here, we report the identification and biochemical characterization of the Drosophila nicotinamidase, D-NAAM, and demonstrate that its overexpression significantly increases median and maximal fly life span. The life span extension was reversed in Sir2 mutant flies, suggesting Sir2 dependence. Testing for physiological effectors of D-NAAM in Drosophila S2 cells, we identified oxidative stress as a primary regulator, both at the transcription level and protein activity. In contrast to the yeast model, stress factors such as high osmolarity and heat shock, calorie restriction, or inhibitors of TOR and phosphatidylinositol 3-kinase pathways do not appear to regulate D-NAAM in S2 cells. Interestingly, the expression of D-NAAM in human neuronal cells conferred protection from oxidative stress-induced cell death in a sirtuin-dependent manner. Together, our findings establish a life span extending the ability of nicotinamidase in flies and offer a role for nicotinamide-modulating genes in oxidative stress regulated pathways influencing longevity and neuronal cell survival.
Two Algorithms for High-throughput and Multi-parametric Quantification of Drosophila Neuromuscular Junction Morphology.

Science.gov (United States)

Castells-Nobau, Anna; Nijhof, Bonnie; Eidhof, Ilse; Wolf, Louis; Scheffer-de Gooyert, Jolanda M; Monedero, Ignacio; Torroja, Laura; van der Laak, Jeroen A W M; Schenck, Annette

2017-05-03

Synaptic morphology is tightly related to synaptic efficacy, and in many cases morphological synapse defects ultimately lead to synaptic malfunction. The Drosophila larval neuromuscular junction (NMJ), a well-established model for glutamatergic synapses, has been extensively studied for decades. Identification of mutations causing NMJ morphological defects revealed a repertoire of genes that regulate synapse development and function. Many of these were identified in large-scale studies that focused on qualitative approaches to detect morphological abnormalities of the Drosophila NMJ. A drawback of qualitative analyses is that many subtle players contributing to NMJ morphology likely remain unnoticed. Whereas quantitative analyses are required to detect the subtler morphological differences, such analyses are not yet commonly performed because they are laborious. This protocol describes in detail two image analysis algorithms "Drosophila NMJ Morphometrics" and "Drosophila NMJ Bouton Morphometrics", available as Fiji-compatible macros, for quantitative, accurate and objective morphometric analysis of the Drosophila NMJ. This methodology is developed to analyze NMJ terminals immunolabeled with the commonly used markers Dlg-1 and Brp. Additionally, its wider application to other markers such as Hrp, Csp and Syt is presented in this protocol. The macros are able to assess nine morphological NMJ features: NMJ area, NMJ perimeter, number of boutons, NMJ length, NMJ longest branch length, number of islands, number of branches, number of branching points and number of active zones in the NMJ terminal.
Electrophysiological Recordings from Lobula Plate Tangential Cells in Drosophila.

Science.gov (United States)

Mauss, Alex S; Borst, Alexander

2016-01-01

Drosophila has emerged as an important model organism for the study of the neural basis of behavior. Its main asset is the experimental accessibility of identified neurons by genetic manipulation and physiological recordings. Drosophila therefore offers the opportunity to reach an integrative understanding of the development and neural underpinnings of behavior at all processing stages, from sensing to motor control, in a single species. Here, we will provide an account of the procedures involved in recording the electrical potential of individual neurons in the visual system of adult Drosophila using the whole-cell patch-clamp method. To this end, animals are fixed to a holder and mounted below a recording chamber. The head capsule is cut open and the glial sheath covering the brain is ruptured by a combination of shearing and enzymatic digest. Neuronal somata are thus exposed and targeted by low-resistance patch electrodes. After formation of a high resistance seal, electrical access to the cell is gained by small current pulses and suction. Stable recordings of large neurons are feasible for >1 h and can be combined with controlled visual stimulation as well as genetic and pharmacological manipulation of upstream circuit elements to infer circuit function in great detail.
Drosophila Courtship Conditioning As a Measure of Learning and Memory

NARCIS (Netherlands)

Koemans, T.S.; Oppitz, C.; Donders, R.; Bokhoven, H. van; Schenck, A.; Keleman, K.; Kramer, J.M.

2017-01-01

Many insights into the molecular mechanisms underlying learning and memory have been elucidated through the use of simple behavioral assays in model organisms such as the fruit fly, Drosophila melanogaster. Drosophila is useful for understanding the basic neurobiology underlying cognitive deficits
Simultaneous determination of local cerebral glucose utilization and blood flow by carbon-14 double-label autoradiography: method of procedure and validation studies in the rat

International Nuclear Information System (INIS)

Ginsberg, M.D.; Smith, D.W.; Wachtel, M.S.; Gonzalez-Carvajal, M.; Busto, R.

1986-01-01

Validation studies were undertaken to establish a computer-assisted double-label autoradiographic strategy employing [ 14 C]2-deoxyglucose ([ 14 C]2DG) and [ 14 C]iodoantipyrine ([ 14 C]IAP) to measure local CMRglu (LCMRglu) and CBF (LCBF). An organic solvent was used to extract the majority of IAP between first and second film exposures. In contrast to previously published data, all solvents tested produced partial losses of 2DG from tissue, and all allowed 2-6% of IAP to persist even after 5-day washes. Technical-grade chloroform permitted equal retention of unmetabolized and metabolized 2DG. A linear model was established, which was insensitive to the changes in tissue self-absorption that were shown to occur with chloroform extraction. Propagated error in computing tissue [ 14 C]2DG and [ 14 C]IAP was reduced by maximizing IAP extraction (by longer solvent wash times) and by administering 2.5 times as much IAP as 2DG. Fractional 2DG retention was measured in single-label 2DG sections placed on the films, and fractional IAP retention was evaluated by an optimization procedure. With this strategy, double-label values for LCMRglu and LCBF in anesthetized rats agreed with values obtained in matched single-label series to within 5%. The coefficients of variation for the double- and single-label LCMRglu data were virtually identical, whereas the coefficient of variation for double-label LCBF was 1.8 times that of single-label LCBF. The double-label strategy permitted pixel-by-pixel measurement and video display of the LCMRglu/LCBF ratio; the mean value among structures was 0.472 mumol/ml. With proper attention to methodological detail, this double-label strategy shows great promise for routine laboratory application
Effect of localized hypoxia on Drosophila embryo development.

Directory of Open Access Journals (Sweden)

Zhinan Wang

Full Text Available Environmental stress, such as oxygen deprivation, affects various cellular activities and developmental processes. In this study, we directly investigated Drosophila embryo development in vivo while cultured on a microfluidic device, which imposed an oxygen gradient on the developing embryos. The designed microfluidic device enabled both temporal and spatial control of the local oxygen gradient applied to the live embryos. Time-lapse live cell imaging was used to monitor the morphology and cellular migration patterns as embryos were placed in various geometries relative to the oxygen gradient. Results show that pole cell movement and tail retraction during Drosophila embryogenesis are highly sensitive to oxygen concentrations. Through modeling, we also estimated the oxygen permeability across the Drosophila embryonic layers for the first time using parameters measured on our oxygen control device.
Cell death in response to antimetabolites directed at ribonucleotide reductase and thymidylate synthase

Science.gov (United States)

Asuncion Valenzuela, Malyn M; Castro, Imilce; Gonda, Amber; Diaz Osterman, Carlos J; Jutzy, Jessica M; Aspe, Jonathan R; Khan, Salma; Neidigh, Jonathan W; Wall, Nathan R

2015-01-01

New agent development, mechanistic understanding, and combinatorial partnerships with known and novel modalities continue to be important in the study of pancreatic cancer and its improved treatment. In this study, known antimetabolite drugs such as gemcitabine (ribonucleotide reductase inhibitor) and 5-fluorouracil (thymidylate synthase inhibitor) were compared with novel members of these two drug families in the treatment of a chemoresistant pancreatic cancer cell line PANC-1. Cellular survival data, along with protein and messenger ribonucleic acid expression for survivin, XIAP, cIAP1, and cIAP2, were compared from both the cell cytoplasm and from exosomes after single modality treatment. While all antimetabolite drugs killed PANC-1 cells in a time- and dose-dependent manner, neither family significantly altered the cytosolic protein level of the four inhibitors of apoptosis (IAPs) investigated. Survivin, XIAP, cIAP1, and cIAP2 were found localized to exosomes where no significant difference in expression was recorded. This inability for significant and long-lasting expression may be a reason why pancreatic cancer lacks responsiveness to these and other cancer-killing agents. Continued investigation is required to determine the responsibilities of these IAPs in their role in chemoresistance in pancreatic adenocarcinoma. PMID:25767396
Sample Preparation and Mounting of Drosophila Embryos for Multiview Light Sheet Microscopy.

Science.gov (United States)

Schmied, Christopher; Tomancak, Pavel

2016-01-01

Light sheet fluorescent microscopy (LSFM), and in particular its most widespread flavor Selective Plane Illumination Microscopy (SPIM), promises to provide unprecedented insights into developmental dynamics of entire living systems. By combining minimal photo-damage with high imaging speed and sample mounting tailored toward the needs of the specimen, it enables in toto imaging of embryogenesis with high spatial and temporal resolution. Drosophila embryos are particularly well suited for SPIM imaging because the volume of the embryo does not change from the single cell embryo to the hatching larva. SPIM microscopes can therefore image Drosophila embryos embedded in rigid media, such as agarose, from multiple angles every few minutes from the blastoderm stage until hatching. Here, we describe sample mounting strategies to achieve such a recording. We also provide detailed protocols to realize multiview, long-term, time-lapse recording of Drosophila embryos expressing fluorescent markers on the commercially available Zeiss Lightsheet Z.1 microscope and the OpenSPIM.
Effects of caffeine or maternal repair systems in Drosophila melanogaster

International Nuclear Information System (INIS)

Osgood, C.; Zimmering, S.

1979-01-01

Drosophila melanogaster females were treated with 1% caffeine, mated with X-rayed males and the frequencies of induced sex-chromosome loss, translocations between the major autosomes and between the Y-chromosome and the major autosomes determined. In a reversal of the results obtained previously with 0.2% caffeine by Mendelson and Sobels, treatment of females with 1% caffeine led to a decrease in sex-chromosome loss, confirming preliminary data of Zimmering and Osgood and in increase in autosome-autosome translocations. It is suggested that the higher concentration of caffeine inhibits replication permitting more time available for chromosome-type restitutions by means of caffeine-insensitive repair mechanisms. In contrast with results for autosome-autosome translocation, the fequency of Y-autosome translocations was depressed below controls suggesting an isolation (by any one of several means) of Y-chromosome breaks from those in the autosomes. (Auth.)
On the difficulties of discriminating between major and minor hybrid male sterility factors in Drosophila by examining the segregation ratio of sterile and fertile sons in backcrossing experiments.

Science.gov (United States)

Maside, X R; Naveira, H F

1996-10-01

The observation of segregation ratios of sterile and fertile males in offspring samples from backcrossed hybrid females is, in principle, a valid method to unveil the genetic basis of hybrid male sterility in Drosophila. When the female parent is heterozygous (hybrid) for a sterility factor with major effects, equal proportions of fertile and sterile sons are expected in her offspring. However, intact (not recombined) chromosome segments of considerable length are expected to give segregation ratios that can not be easily differentiated from the 1:1 ratio expected from a single factor. When the phenotypic character under analysis can be determined by combinations of minor factors from the donor species spanning a certain chromosome length, very large offspring samples may be needed to test this alternative hypothesis against the null hypothesis of a single major factor. This is particularly the case of hybrid male sterility determinants in Drosophila.
Curcumin Promotes A-beta Fibrillation and Reduces Neurotoxicity in Transgenic Drosophila

Science.gov (United States)

Caesar, Ina; Jonson, Maria; Nilsson, K. Peter R.; Thor, Stefan; Hammarström, Per

2012-01-01

The pathology of Alzheimer's disease (AD) is characterized by the presence of extracellular deposits of misfolded and aggregated amyloid-β (Aβ) peptide and intraneuronal accumulation of tangles comprised of hyperphosphorylated Tau protein. For several years, the natural compound curcumin has been proposed to be a candidate for enhanced clearance of toxic Aβ amyloid. In this study we have studied the potency of feeding curcumin as a drug candidate to alleviate Aβ toxicity in transgenic Drosophila. The longevity as well as the locomotor activity of five different AD model genotypes, measured relative to a control line, showed up to 75% improved lifespan and activity for curcumin fed flies. In contrast to the majority of studies of curcumin effects on amyloid we did not observe any decrease in the amount of Aβ deposition following curcumin treatment. Conformation-dependent spectra from p-FTAA, a luminescent conjugated oligothiophene bound to Aβ deposits in different Drosophila genotypes over time, indicated accelerated pre-fibrillar to fibril conversion of Aβ1–42 in curcumin treated flies. This finding was supported by in vitro fibrillation assays of recombinant Aβ1–42. Our study shows that curcumin promotes amyloid fibril conversion by reducing the pre-fibrillar/oligomeric species of Aβ, resulting in a reduced neurotoxicity in Drosophila. PMID:22348084
Serotonin receptors expressed in Drosophila mushroom bodies differentially modulate larval locomotion.

Directory of Open Access Journals (Sweden)

Bryon Silva

Full Text Available Drosophila melanogaster has been successfully used as a simple model to study the cellular and molecular mechanisms underlying behaviors, including the generation of motor programs. Thus, it has been shown that, as in vertebrates, CNS biogenic amines (BA including serotonin (5HT participate in motor control in Drosophila. Several evidence show that BA systems innervate an important association area in the insect brain previously associated to the planning and/or execution of motor programs, the Mushroom Bodies (MB. The main objective of this work is to evaluate the contribution of 5HT and its receptors expressed in MB to motor behavior in fly larva. Locomotion was evaluated using an automated tracking system, in Drosophila larvae (3(rd-instar exposed to drugs that affect the serotonergic neuronal transmission: alpha-methyl-L-dopa, MDMA and fluoxetine. In addition, animals expressing mutations in the 5HT biosynthetic enzymes or in any of the previously identified receptors for this amine (5HT1AR, 5HT1BR, 5HT2R and 5HT7R were evaluated in their locomotion. Finally, RNAi directed to the Drosophila 5HT receptor transcripts were expressed in MB and the effect of this manipulation on motor behavior was assessed. Data obtained in the mutants and in animals exposed to the serotonergic drugs, suggest that 5HT systems are important regulators of motor programs in fly larvae. Studies carried out in animals pan-neuronally expressing the RNAi for each of the serotonergic receptors, support this idea and further suggest that CNS 5HT pathways play a role in motor control. Moreover, animals expressing an RNAi for 5HT1BR, 5HT2R and 5HT7R in MB show increased motor behavior, while no effect is observed when the RNAi for 5HT1AR is expressed in this region. Thus, our data suggest that CNS 5HT systems are involved in motor control, and that 5HT receptors expressed in MB differentially modulate motor programs in fly larvae.
Genetic monitoring of irradiated Drosophila populations treated with antimutagen melanine

International Nuclear Information System (INIS)

Mosseh, I.B.; Savchenko, V.K.; Lyakh, I.P.

1986-01-01

It was shown that viability of irradiated Drosophila is, on an average, lower than in intact populations. The fertility first decreases then increases exceeding the control level. Melanine added to the diet increases fertility and viability of both exposed and intact Drosophila populations

Starvation-Induced Dietary Behaviour in Drosophila melanogaster Larvae and Adults.

Science.gov (United States)

Ahmad, Muhammad; Chaudhary, Safee Ullah; Afzal, Ahmed Jawaad; Tariq, Muhammad

2015-09-24

Drosophila melanogaster larvae are classified as herbivores and known to feed on non-carnivorous diet under normal conditions. However, when nutritionally challenged these larvae exhibit cannibalistic behaviour by consuming a diet composed of larger conspecifics. Herein, we report that cannibalism in Drosophila larvae is confined not only to scavenging on conspecifics that are larger in size, but also on their eggs. Moreover, such cannibalistic larvae develop as normally as those grown on standard cornmeal medium. When stressed, Drosophila melanogaster larvae can also consume a carnivorous diet derived from carcasses of organisms belonging to diverse taxonomic groups, including Musca domestica, Apis mellifera, and Lycosidae sp. While adults are ill-equipped to devour conspecific carcasses, they selectively oviposit on them and also consume damaged cadavers of conspecifics. Thus, our results suggest that nutritionally stressed Drosophila show distinct as well as unusual feeding behaviours that can be classified as detritivorous, cannibalistic and/or carnivorous.
Three new species of Drosophila tripunctata group (Diptera: Drosophilidae in the eastern Andes of Ecuador

Directory of Open Access Journals (Sweden)

Emily Ramos Guillín

2015-12-01

Full Text Available Three new species of the Drosophila tripunctata group are described and illustrated. These new species were captured using plastic bottles containing pieces of fermented banana with yeast. The collections were from Napo Province, Ecuador at 2 200 m and 3 362 m above sea level. The new species are: Drosophila napoensis sp. nov., Drosophila cuyuja sp. nov. and Drosophila quijos sp. nov. The first two species belong to subgroup I and the latter species belong to subgroup III of the Drosophila tripunctata group.
Structural insights into the neuroprotective-acting carbonyl reductase Sniffer of Drosophila melanogaster.

Science.gov (United States)

Sgraja, Tanja; Ulschmid, Julia; Becker, Katja; Schneuwly, Stephan; Klebe, Gerhard; Reuter, Klaus; Heine, Andreas

2004-10-01

In vivo studies with the fruit-fly Drosophila melanogaster have shown that the Sniffer protein prevents age-dependent and oxidative stress-induced neurodegenerative processes. Sniffer is a NADPH-dependent carbonyl reductase belonging to the enzyme family of short-chain dehydrogenases/reductases (SDRs). The crystal structure of the homodimeric Sniffer protein from Drosophila melanogaster in complex with NADP+ has been determined by multiple-wavelength anomalous dispersion and refined to a resolution of 1.75 A. The observed fold represents a typical dinucleotide-binding domain as detected for other SDRs. With respect to the cofactor-binding site and the region referred to as substrate-binding loop, the Sniffer protein shows a striking similarity to the porcine carbonyl reductase (PTCR). This loop, in both Sniffer and PTCR, is substantially shortened compared to other SDRs. In most enzymes of the SDR family this loop adopts a well-defined conformation only after substrate binding and remains disordered in the absence of any bound ligands or even if only the dinucleotide cofactor is bound. In the structure of the Sniffer protein, however, the conformation of this loop is well defined, although no substrate is present. Molecular modeling studies provide an idea of how binding of substrate molecules to Sniffer could possibly occur.
Using Neurogenetics and the Warmth-Gated Ion Channel TRPA1 to Study the Neural Basis of Behavior in Drosophila.

Science.gov (United States)

Berni, Jimena; Muldal, Alistair M; Pulver, Stefan R

2010-01-01

Here we describe a set of straightforward laboratory exercises that integrate the study of genetics, neuroanatomy, cellular physiology and animal behavior. We use genetic tools in Drosophila for visualizing and remotely activating ensembles of neurons with heat pulses. First, we show how to examine the anatomy of several neuronal populations using genetically encoded green fluorescent protein. Next we demonstrate how to use the warmth gated Drosophila TRPA1 (dTRPA1) cation channel to remotely activate neural circuits in flies. To demonstrate the cellular effects of dTRPA1 activation, we expressed dTRPA1 panneurally and recorded excitatory junctional potentials in muscles in response to warmed (29°C) saline. Finally, we present inexpensive techniques for delivering heat pulses to activate dTRPA1 in the neuronal groups we observed previously while flies are freely behaving. We suggest how to film and quantify resulting behavioral phenotypes with limited resources. Activating all neurons with dTRPA1 caused tetanic paralysis in larvae, while in adults it led to paralysis in males and continuous uncoordinated leg and wing movements in females. Activation of cholinergic neurons produced spasms and writhing in larvae while causing paralysis in adults. When a single class of nociceptive sensory neurons was activated, it caused lateral rolling in larvae, but no discernable effects in adults. Overall, these exercises illustrate principles of modern genetics, neuroanatomy, the ionic basis of neuronal excitability, and quantitative methods in neuroethology. Relatively few research studies have used dTRPA1 to activate neural circuits, so these exercises give students opportunities to test novel hypotheses and make actual contributions to the scientific record.
Ionizing radiation causes the stress response in Drosophila melanogaster

International Nuclear Information System (INIS)

Gruntenko, N.E.; Zakharenko, L.P.; Raushenbakh, I.Yu.

1998-01-01

Potentiality of the stress-reaction arising in Drosophila melanogaster under gamma-irradiation of the source with 137 Cs (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 [ru
Isolation and characterization of an insulin-degrading enzyme from Drosophila melanogaster

International Nuclear Information System (INIS)

Garcia, J.V.; Fenton, B.W.; Rosner, M.R.

1988-01-01

An insulin-degrading enzyme (IDE) from the cytoplasm of Drosophila Kc cells has been purified and characterized. The purified enzyme is a monomer with an s value of 7.2 S, an apparent K/sub m/ for porcine insulin of 3 μM, and a specific activity of 3.3 nmol of porcine insulin degraded/(min x mg). N-Terminal sequence analysis of the gel-purified enzyme gave a single, serine-rich sequence. The Drosophila IDE shares a number of properties in common with its mammalian counterpart. The enzyme could be specifically affinity-labeled with [ 125 I]insulin, has a molecular weight of 110K, and has a pI of 5.3. Although Drosophila Kc cells grow at room temperature, the optimal enzyme activity assay conditions parallel those of the mammalian IDE: 37 0 C and a pH range of 7-8. The Drosophila IDE activity, like the mammalian enzymes, is inhibited by bacitracin and sulfhydryl-specific reagents. Similarly, the Drosophila IDE activity is insensitive to glutathione as well as protease inhibitors such as aprotinin and leupeptin. Insulin-like growth factor II, equine insulin, and porcine insulin compete for degradation of [ 125 I]insulin at comparable concentrations (approximately 10 -6 M), whereas insulin-like growth factor I and the individual A and B chains of insulin are less effective. The high degree of evolutionary conservation between the Drosophila and mammalian IDE suggest an important role for this enzyme in the metabolism of insulin and also provides further evidence for the existence of a complete insulin-like system in invertebrate organisms such as Drosophila
Comparative genomic analysis of Drosophila melanogaster and vector mosquito developmental genes.

Directory of Open Access Journals (Sweden)

Susanta K Behura

Full Text Available Genome sequencing projects have presented the opportunity for analysis of developmental genes in three vector mosquito species: Aedes aegypti, Culex quinquefasciatus, and Anopheles gambiae. A comparative genomic analysis of developmental genes in Drosophila melanogaster and these three important vectors of human disease was performed in this investigation. While the study was comprehensive, special emphasis centered on genes that 1 are components of developmental signaling pathways, 2 regulate fundamental developmental processes, 3 are critical for the development of tissues of vector importance, 4 function in developmental processes known to have diverged within insects, and 5 encode microRNAs (miRNAs that regulate developmental transcripts in Drosophila. While most fruit fly developmental genes are conserved in the three vector mosquito species, several genes known to be critical for Drosophila development were not identified in one or more mosquito genomes. In other cases, mosquito lineage-specific gene gains with respect to D. melanogaster were noted. Sequence analyses also revealed that numerous repetitive sequences are a common structural feature of Drosophila and mosquito developmental genes. Finally, analysis of predicted miRNA binding sites in fruit fly and mosquito developmental genes suggests that the repertoire of developmental genes targeted by miRNAs is species-specific. The results of this study provide insight into the evolution of developmental genes and processes in dipterans and other arthropods, serve as a resource for those pursuing analysis of mosquito development, and will promote the design and refinement of functional analysis experiments.
'Peer pressure' in larval Drosophila?

Science.gov (United States)

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

2014-06-06

Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila. © 2014. Published by The Company of Biologists Ltd.
Mutagenic effect of tritium on DNA of Drosophila melanogaster: Technical progress report, December 15, 1986-July 15, 1987

International Nuclear Information System (INIS)

Lee, W.R.

1987-01-01

Recombinant DNA techniques were used to analyze mutants induced by either tritium or x-ray. Mutations induced at the alcohol dehydrogenase locus (Adh) in Drosophila melanogaster were first characterized by genetic complementation tests to determine if a multi-locus deletion has occurred. Mutants that are intragenic as defined by the complementation test are then placed opposite a deficiency so that the DNA from the mutant allele may be extracted and analyzed. Part I of the project is to analyze mutants induced by ionizing radiation with molecular techniques, and part II is to determine the molecular effects of these mutant phenotypes on their expression in the polypeptide produced by the mutant gene. Part III of this project consists of inducing mutants with tritiated water at the Adh locus in D. melanogaster. We have reported the development of a feeding method for exposing male D. melanogaster to tritiated water that would give a range in dose from 6.66 Gy to 26.64 Gy. This method of exposing Drosophila was used first to study a dose response curve for tritium using as a genetic endpoint the sex-linked recessive lethal test. 3 figs., 1 tab
Gemcitabine inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells.

Science.gov (United States)

Yong-Xian, Gui; Xiao-Huan, Li; Fan, Zhang; Guo-Fang, Tian

2016-10-01

The aim of the study is to investigate the underlying molecular mechanisms by which gemcitabine (gem) inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells in vitro. After PANC-1 cells had been treated by indicated concentration (0, 5, and 25 mg/L) of gem for 48 h, cell proliferation was evaluated by 3'-(4, 5 dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay; cell morphology was observed by transmission electron microscopy; Expression of c-IAP2 and Bcl-2 proteins was analyzed by Western blot; the activity of caspase-3 and -9 was detected by spectrophotometry. Gem significantly inhibited cell proliferation and could induce apoptosis of human pancreatic cancer PANC-1 cells, with a dose-dependent manner. Western blot analysis showed that gem significantly reduced c-IAP2 and Bcl-2 proteins expression level (P PANC-1 cells. Gem could induce apoptosis of human pancreatic cancer PANC-1 cells, probably through downregulating c-IAP2 and Bcl-2 expression levels, and at the same time activating caspase-3 and -9.
Drosophila SMN complex proteins Gemin2, Gemin3, and Gemin5 are components of U bodies

International Nuclear Information System (INIS)

Cauchi, Ruben J.; Sanchez-Pulido, Luis; Liu, Ji-Long

2010-01-01

Uridine-rich small nuclear ribonucleoproteins (U snRNPs) play key roles in pre-mRNA processing in the nucleus. The assembly of most U snRNPs takes place in the cytoplasm and is facilitated by the survival motor neuron (SMN) complex. Discrete cytoplasmic RNA granules called U bodies have been proposed to be specific sites for snRNP assembly because they contain U snRNPs and SMN. U bodies invariably associate with P bodies, which are involved in mRNA decay and translational control. However, it remains unknown whether other SMN complex proteins also localise to U bodies. In Drosophila there are four SMN complex proteins, namely SMN, Gemin2/CG10419, Gemin3 and Gemin5/Rigor mortis. Drosophila Gemin3 was originally identified as the Drosophila orthologue of human and yeast Dhh1, a component of P bodies. Through an in silico analysis of the DEAD-box RNA helicases we confirmed that Gemin3 is the bona fide Drosophila orthologue of vertebrate Gemin3 whereas the Drosophila orthologue of Dhh1 is Me31B. We then made use of the Drosophila egg chamber as a model system to study the subcellular distribution of the Gemin proteins as well as Me31B. Our cytological investigations show that Gemin2, Gemin3 and Gemin5 colocalise with SMN in U bodies. Although they are excluded from P bodies, as components of U bodies, Gemin2, Gemin3 and Gemin5 are consistently found associated with P bodies, wherein Me31B resides. In addition to a role in snRNP biogenesis, SMN complexes residing in U bodies may also be involved in mRNP assembly and/or transport.
Drosophila SMN complex proteins Gemin2, Gemin3, and Gemin5 are components of U bodies

Energy Technology Data Exchange (ETDEWEB)

Cauchi, Ruben J.; Sanchez-Pulido, Luis [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX (United Kingdom); Liu, Ji-Long, E-mail: jilong.liu@dpag.ox.ac.uk [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX (United Kingdom)

2010-08-15

Uridine-rich small nuclear ribonucleoproteins (U snRNPs) play key roles in pre-mRNA processing in the nucleus. The assembly of most U snRNPs takes place in the cytoplasm and is facilitated by the survival motor neuron (SMN) complex. Discrete cytoplasmic RNA granules called U bodies have been proposed to be specific sites for snRNP assembly because they contain U snRNPs and SMN. U bodies invariably associate with P bodies, which are involved in mRNA decay and translational control. However, it remains unknown whether other SMN complex proteins also localise to U bodies. In Drosophila there are four SMN complex proteins, namely SMN, Gemin2/CG10419, Gemin3 and Gemin5/Rigor mortis. Drosophila Gemin3 was originally identified as the Drosophila orthologue of human and yeast Dhh1, a component of P bodies. Through an in silico analysis of the DEAD-box RNA helicases we confirmed that Gemin3 is the bona fide Drosophila orthologue of vertebrate Gemin3 whereas the Drosophila orthologue of Dhh1 is Me31B. We then made use of the Drosophila egg chamber as a model system to study the subcellular distribution of the Gemin proteins as well as Me31B. Our cytological investigations show that Gemin2, Gemin3 and Gemin5 colocalise with SMN in U bodies. Although they are excluded from P bodies, as components of U bodies, Gemin2, Gemin3 and Gemin5 are consistently found associated with P bodies, wherein Me31B resides. In addition to a role in snRNP biogenesis, SMN complexes residing in U bodies may also be involved in mRNP assembly and/or transport.
Radiation effects on the drosophila melanogaster genoma

International Nuclear Information System (INIS)

Arceo-Maldonado, C.

1989-01-01

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)
Associations of maximal voluntary isometric hip extension torque with muscle size of hamstring and gluteus maximus and intra-abdominal pressure.

Science.gov (United States)

Tayashiki, Kota; Hirata, Kosuke; Ishida, Kiraku; Kanehisa, Hiroaki; Miyamoto, Naokazu

2017-06-01

Muscle size of the hamstring and gluteus maximus (GM) as well as intra-abdominal pressure (IAP) are considered as factors affecting the torque development during hip extension. This study examined the associations of torque development during maximal voluntary isometric hip extension with IAP and muscle size of the hamstring and GM. Anatomical cross-sectional area (ACSA) of the hamstring and thickness of GM were determined in 20 healthy young males using an ultrasonography apparatus (Experiment 1). Torque and IAP were simultaneously measured while subjects performed maximal voluntary isometric hip extension. The IAP was measured using a pressure transducer placed in the rectum and determined at the time at which the developed torque reached to the maximal. In Experiment 2, torque and IAP were measured during maximal voluntary isometric hip flexion in 18 healthy young males. The maximal hip extension torque was significantly correlated with the IAP (r = 0.504, P = 0.024), not with the ACSA of the hamstring (r = 0.307, P = 0.188) or the thickness of GM (r = 0.405, P = 0.076). The relationship was still significant even when the ACSA of the hamstring and the thickness of GM were adjusted statistically (r = 0.486, P = 0.041). The maximal hip flexion torque was not significantly correlated with the IAP (r = -0.118, P = 0.642). The current results suggest that IAP can contribute independently of the muscle size of the agonists to maximal voluntary hip extension torque.
Intraabdominal pressure in women during CrossFit exercises and the effect of age and parity.

Science.gov (United States)

Gephart, Laura Faye; Doersch, Karen M; Reyes, Michelle; Kuehl, Thomas J; Danford, Jill M

2018-07-01

To determine intraabdominal pressure (IAP) in women during CrossFit and to determine whether parity, age, or CrossFit experience affects IAP during CrossFit exercises, we evaluated 10 women: 5 experienced and active CrossFitters and 5 who were not regularly engaged in CrossFit. A Laborie urodynamics abdominal pressure probe with the Goby wireless system measured IAP during 10 repetitions of 13 different CrossFit exercises. Women had a mean age of 36 years. A significant difference was found between mean peak IAP of the 5 parous vs the 5 nulliparous women ( P = 0.009). Experience with CrossFit did not affect mean peak IAP achieved with exercise. In some exercises, there was a significant change in IAP as participants progressed through repetitions ( P = 0.003 for back squats and 0.04 for sit-ups). Participants achieved IAP values that were markedly higher than those previously published.
Exposure-dependent variation in cryolite induced lethality in the nontarget insect, Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Podder Sayanti

2014-03-01

Full Text Available The starting point of toxicity testing of any chemical in an organism is the determination of its Lethal Concentration 50 (LC50. In the present study, LC50 of a fluorinated insecticide cryolite is determined in a non-target insect model, Drosophila melanogaster. Interestingly, the result shows that acute LC50 of cryolite was much greater in comparison to the chronic one in case of Drosophila larvae. Larvae which were exposed to 65,000 to 70,000 μg/ml cryolite through food showed 50% mortality after 18 hours of acute exposure, whereas only 150 to 160 μg/ml cryolite was sufficient to cause 50% mortality in case of chronic exposure. Thus cryolite in a small amount when applied once cannot produce noticeable changes in Drosophila, whereas the same amount when used continuously can be fatal. The non-feeding pupal stage was also seen to be affected by chemical treatment. This suggests that the test chemical affects the developmental fate and results in failure of adult emergence. Absence of chemical-induced mortality in adults assumes that the toxicity of cryolite might be restricted to the preimaginal stages of the organism. Reduction in body size of larvae after ingestion of cryolite (with food in acute treatment schedule is another interesting finding of this study. Some individuals consuming cryolite containing food cannot survive whereas the few survivors manifest a significant growth retardation which might be due to a tendency of refusal in feeding. Hence the present findings provide a scope of assessment of risk of other similar non-target groups
Evolutionary genetics: the Drosophila model

Indian Academy of Sciences (India)

Unknown

Evolutionary genetics straddles the two fundamental processes of life, ... of the genus Drosophila have been used extensively as model systems in experimental ... issue will prove interesting, informative and thought-provoking for both estab-.
Phospho-regulated Drosophila adducin is a determinant of synaptic plasticity in a complex with Dlg and PIP2 at the larval neuromuscular junction

Directory of Open Access Journals (Sweden)

Simon Ji Hau Wang

2014-11-01

Full Text Available Adducin is a ubiquitously expressed actin- and spectrin-binding protein involved in cytoskeleton organization, and is regulated through phosphorylation of the myristoylated alanine-rich C-terminal kinase (MARCKS-homology domain by protein kinase C (PKC. We have previously shown that the Drosophila adducin, Hu-li tai shao (Hts, plays a role in larval neuromuscular junction (NMJ growth. Here, we find that the predominant isoforms of Hts at the NMJ contain the MARCKS-homology domain, which is important for interactions with Discs large (Dlg and phosphatidylinositol 4,5-bisphosphate (PIP2. Through the use of Proximity Ligation Assay (PLA, we show that the adducin-like Hts isoforms are in complexes with Dlg and PIP2 at the NMJ. We provide evidence that Hts promotes the phosphorylation and delocalization of Dlg at the NMJ through regulation of the transcript distribution of the PAR-1 and CaMKII kinases in the muscle. We also show that Hts interactions with Dlg and PIP2 are impeded through phosphorylation of the MARCKS-homology domain. These results are further evidence that Hts is a signaling-responsive regulator of synaptic plasticity in Drosophila.
Drosophila melanogaster as an animal model for the study of Pseudomonas aeruginosa biofilm infections in vivo.

Directory of Open Access Journals (Sweden)

Heidi Mulcahy

2011-10-01

Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen capable of causing both acute and chronic infections in susceptible hosts. Chronic P. aeruginosa infections are thought to be caused by bacterial biofilms. Biofilms are highly structured, multicellular, microbial communities encased in an extracellular matrix that enable long-term survival in the host. The aim of this research was to develop an animal model that would allow an in vivo study of P. aeruginosa biofilm infections in a Drosophila melanogaster host. At 24 h post oral infection of Drosophila, P. aeruginosa biofilms localized to and were visualized in dissected Drosophila crops. These biofilms had a characteristic aggregate structure and an extracellular matrix composed of DNA and exopolysaccharide. P. aeruginosa cells recovered from in vivo grown biofilms had increased antibiotic resistance relative to planktonically grown cells. In vivo, biofilm formation was dependent on expression of the pel exopolysaccharide genes, as a pelB::lux mutant failed to form biofilms. The pelB::lux mutant was significantly more virulent than PAO1, while a hyperbiofilm strain (PAZHI3 demonstrated significantly less virulence than PAO1, as indicated by survival of infected flies at day 14 postinfection. Biofilm formation, by strains PAO1 and PAZHI3, in the crop was associated with induction of diptericin, cecropin A1 and drosomycin antimicrobial peptide gene expression 24 h postinfection. In contrast, infection with the non-biofilm forming strain pelB::lux resulted in decreased AMP gene expression in the fly. In summary, these results provide novel insights into host-pathogen interactions during P. aeruginosa oral infection of Drosophila and highlight the use of Drosophila as an infection model that permits the study of P. aeruginosa biofilms in vivo.
The genetic basis of Haldane's rule and the nature of asymmetric hybrid male sterility among Drosophila simulans, Drosophila mauritiana and Drosophila sechellia.

Science.gov (United States)

Zeng, L W; Singh, R S

1993-05-01

Haldane's rule (i.e., the preferential hybrid sterility and inviability of heterogametic sex) has been known for 70 years, but its genetic basis, which is crucial to the understanding of the process of species formation, remains unclear. In the present study, we have investigated the genetic basis of hybrid male sterility using Drosophila simulans, Drosophila mauritiana and Drosophila sechellia. An introgression of D. sechellia Y chromosome into a fairly homogenous background of D. simulans did not show any effect of the introgressed Y on male sterility. The substitution of D. simulans Y chromosome into D. sechellia, and both reciprocal Y chromosome substitutions between D. simulans and D. mauritiana were unsuccessful. Introgressions of cytoplasm between D. simulans and D. mauritiana (or D. sechellia) also did not have any effect on hybrid male sterility. These results rule out the X-Y interaction hypothesis as a general explanation of Haldane's rule in this species group and indicate an involvement of an X-autosome interaction. Models of symmetrical and asymmetrical X-autosome interaction have been developed which explain the Y chromosome substitution results and suggest that evolution of interactions between different genetic elements in the early stages of speciation is more likely to be of an asymmetrical nature. The model of asymmetrical X-autosome interaction also predicts that different sets of interacting genes may be involved in different pairs of related species and can account for the observation that hybrid male sterility in many partially isolated species is often nonreciprocal or unidirectional.

Hypoxia modifies the feeding preferences of Drosophila. Consequences for diet dependent hypoxic survival

Directory of Open Access Journals (Sweden)

Frelin Christian

2010-05-01

Full Text Available Abstract Background Recent attention has been given to the relationships between diet, longevity, aging and resistance to various forms of stress. Flies do not simply ingest calories. They sense different concentrations of carbohydrate and protein macronutrients and they modify their feeding behavior in response to changes in dietary conditions. Chronic hypoxia is a major consequence of cardiovascular diseases. Dietary proteins have recently been shown to decrease the survival of chronically hypoxic Drosophila. Whether flies modify their feeding behavior in response to hypoxia is not currently known. This study uses the recently developed capillary feeding assay to analyze the feeding behavior of normoxic and chronically hypoxic Drosophila melanogaster. Results The intakes rates of sucrose and yeast by normoxic or chronically hypoxic flies (5% O2 were analyzed under self selecting and "no choice" conditions. Chronically hypoxic flies fed on pure yeast diets or mixed diets under self selection conditions stopped feeding on yeast. Flies fed on mixed diets under "no choice" conditions reduced their food intakes. Hypoxia did not modify the adaptation of flies to diluted diets or to imbalanced diets. Mortality was assessed in parallel experiments. Dietary yeast had two distinct effects on hypoxic flies (i a repellent action which eventually led to starvation and which was best observed in the absence of dietary sucrose and (ii a toxic action which led to premature death. Finally we determined that hypoxic survivals were correlated to the intakes of sucrose, which suggested that dietary yeast killed flies by reducing their intake of sucrose. The feeding preferences of adult Drosophila were insensitive to NO scavengers, NO donor molecules and inhibitors of phosphodiesterases which are active on Drosophila larvae. Conclusion Chronically hypoxic flies modify their feeding behavior. They avoid dietary yeast which appears to be toxic. Hypoxic survival is
Body size and mating success in Drosophila willistoni are ...

Indian Academy of Sciences (India)

Mating activity and wing length were investigated in the F1 progeny of Drosophila willistoni females collected in the field to examine any possible relationship between body size and mating success. The flies were observed in a mating chamber under laboratory conditions. No significant differences in wing length were ...
REDfly: a Regulatory Element Database for Drosophila.

Science.gov (United States)

Gallo, Steven M; Li, Long; Hu, Zihua; Halfon, Marc S

2006-02-01

Bioinformatics studies of transcriptional regulation in the metazoa are significantly hindered by the absence of readily available data on large numbers of transcriptional cis-regulatory modules (CRMs). Even the richly annotated Drosophila melanogaster genome lacks extensive CRM information. We therefore present here a database of Drosophila CRMs curated from the literature complete with both DNA sequence and a searchable description of the gene expression pattern regulated by each CRM. This resource should greatly facilitate the development of computational approaches to CRM discovery as well as bioinformatics analyses of regulatory sequence properties and evolution.
Crystal Structure and Substrate Specificity of Drosophila 3,4-Dihydroxyphenylalanine Decarboxylase

Energy Technology Data Exchange (ETDEWEB)

Han, Q.; Ding, H; Robinson, H; Christensen, B; Li, J

2010-01-01

3,4-Dihydroxyphenylalanine decarboxylase (DDC), also known as aromatic L-amino acid decarboxylase, catalyzes the decarboxylation of a number of aromatic L-amino acids. Physiologically, DDC is responsible for the production of dopamine and serotonin through the decarboxylation of 3,4-dihydroxyphenylalanine and 5-hydroxytryptophan, respectively. In insects, both dopamine and serotonin serve as classical neurotransmitters, neuromodulators, or neurohormones, and dopamine is also involved in insect cuticle formation, eggshell hardening, and immune responses. In this study, we expressed a typical DDC enzyme from Drosophila melanogaster, critically analyzed its substrate specificity and biochemical properties, determined its crystal structure at 1.75 Angstrom resolution, and evaluated the roles residues T82 and H192 play in substrate binding and enzyme catalysis through site-directed mutagenesis of the enzyme. Our results establish that this DDC functions exclusively on the production of dopamine and serotonin, with no activity to tyrosine or tryptophan and catalyzes the formation of serotonin more efficiently than dopamine. The crystal structure of Drosophila DDC and the site-directed mutagenesis study of the enzyme demonstrate that T82 is involved in substrate binding and that H192 is used not only for substrate interaction, but for cofactor binding of drDDC as well. Through comparative analysis, the results also provide insight into the structure-function relationship of other insect DDC-like proteins.
Crystal structure and substrate specificity of Drosophila 3,4-dihydroxyphenylalanine decarboxylase.

Directory of Open Access Journals (Sweden)

Qian Han

2010-01-01

Full Text Available 3,4-Dihydroxyphenylalanine decarboxylase (DDC, also known as aromatic L-amino acid decarboxylase, catalyzes the decarboxylation of a number of aromatic L-amino acids. Physiologically, DDC is responsible for the production of dopamine and serotonin through the decarboxylation of 3,4-dihydroxyphenylalanine and 5-hydroxytryptophan, respectively. In insects, both dopamine and serotonin serve as classical neurotransmitters, neuromodulators, or neurohormones, and dopamine is also involved in insect cuticle formation, eggshell hardening, and immune responses.In this study, we expressed a typical DDC enzyme from Drosophila melanogaster, critically analyzed its substrate specificity and biochemical properties, determined its crystal structure at 1.75 Angstrom resolution, and evaluated the roles residues T82 and H192 play in substrate binding and enzyme catalysis through site-directed mutagenesis of the enzyme. Our results establish that this DDC functions exclusively on the production of dopamine and serotonin, with no activity to tyrosine or tryptophan and catalyzes the formation of serotonin more efficiently than dopamine.The crystal structure of Drosophila DDC and the site-directed mutagenesis study of the enzyme demonstrate that T82 is involved in substrate binding and that H192 is used not only for substrate interaction, but for cofactor binding of drDDC as well. Through comparative analysis, the results also provide insight into the structure-function relationship of other insect DDC-like proteins.
Late replication domains are evolutionary conserved in the Drosophila genome.

Science.gov (United States)

Andreyenkova, Natalya G; Kolesnikova, Tatyana D; Makunin, Igor V; Pokholkova, Galina V; Boldyreva, Lidiya V; Zykova, Tatyana Yu; Zhimulev, Igor F; Belyaeva, Elena S

2013-01-01

Drosophila chromosomes are organized into distinct domains differing in their predominant chromatin composition, replication timing and evolutionary conservation. We show on a genome-wide level that genes whose order has remained unaltered across 9 Drosophila species display late replication timing and frequently map to the regions of repressive chromatin. This observation is consistent with the existence of extensive domains of repressive chromatin that replicate extremely late and have conserved gene order in the Drosophila genome. We suggest that such repressive chromatin domains correspond to a handful of regions that complete replication at the very end of S phase. We further demonstrate that the order of genes in these regions is rarely altered in evolution. Substantial proportion of such regions significantly coincide with large synteny blocks. This indicates that there are evolutionary mechanisms maintaining the integrity of these late-replicating chromatin domains. The synteny blocks corresponding to the extremely late-replicating regions in the D. melanogaster genome consistently display two-fold lower gene density across different Drosophila species.
Adaptive dynamics of cuticular hydrocarbons in Drosophila

Czech Academy of Sciences Publication Activity Database

Rajpurohit, S.; Hanus, Robert; Vrkoslav, Vladimír; Behrman, E. L.; Bergland, A. O.; Petrov, D.; Cvačka, Josef; Schmidt, P. S.

2017-01-01

Roč. 30, č. 1 (2017), s. 66-80 ISSN 1010-061X R&D Projects: GA ČR GAP206/12/1093 Institutional support: RVO:61388963 Keywords : cuticular hydrocarbons * Drosophila * experimental evolution * spatiotemporal variation * thermal plasticity Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 2.792, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/jeb.12988/full
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...
Functional analysis of the glycogen binding subunit CG9238/Gbs-70E of protein phosphatase 1 in Drosophila melanogaster.

Science.gov (United States)

Kerekes, Éva; Kókai, Endre; Páldy, Ferenc Sándor; Dombrádi, Viktor

2014-06-01

The product of the CG9238 gene that we termed glycogen binding subunit 70E (Gbs-70E) was characterized by biochemical and molecular genetics methods. The interaction between Gbs-70E and all catalytic subunits of protein phosphatase 1 (Pp1-87B, Pp1-9C, Pp1-96A and Pp1-13C) of Drosophila melanogaster was confirmed by pairwise yeast two-hybrid tests, co-immunoprecipitation and pull down experiments. The binding of Gbs-70E to glycogen was demonstrated by sedimentation analysis. With RT-PCR we found that the mRNAs coding for the longer Gbs-70E PB/PC protein were expressed in all developmental stages of the fruit flies while the mRNA for the shorter Gbs-70E PA was restricted to the eggs and the ovaries of the adult females. The development specific expression of the shorter splice variant was not conserved in different Drosophila species. The expression level of the gene was manipulated by P-element insertions and gene deletion to analyze the functions of the gene product. A small or moderate reduction in the gene expression resulted in no significant changes, however, a deletion mutant expressing very low level of the transcript lived shorter and exhibited reduced glycogen content in the imagos. In addition, the gene deletion decreased the fertility of the fruit flies. Our results prove that Gbs-70E functions as the glycogen binding subunit of protein phosphatase 1 that regulates glycogen content and plays a role in the development of eggs in D. melanogaster. Copyright © 2014 Elsevier Ltd. All rights reserved.
Context effects on emotional and aesthetic evaluations of artworks and IAPS pictures.

Science.gov (United States)

Gerger, Gernot; Leder, Helmut; Kremer, Alexandra

2014-09-01

In the arts emotionally negative objects sometimes can be positively judged. Defining an object as art possibly yields specific changes in how perceivers emotionally experience and aesthetically judge a stimulus. To study how emotional experiences (joy, anger, disgust, fear, sadness, and shame ratings, plus facial EMG) and aesthetic judgements (liking ratings) are modulated by an art context ("This is an artwork") as compared to non-art reality context ("This is a press photograph") participants evaluated IAPS pictures and veridical artworks depicting emotionally positive and negative content. In line with the assumption that emotional distancing is an essential feature of the art experience we found that positive emotional reactions were attenuated (joy, M. zygomaticus activation) in an art compared to non-art context. However, context had little influence on negative emotional reactions (anger, disgust, fear, sadness, shame, and M. corrugator activation) suggesting that these are similar in art and non-art. Importantly, only artworks of emotionally negative content were judged more positively in an art context - thus liked more. This study, in accordance with the assumption of a distanced aesthetic mode, shows that an art context fosters appraisal processes that influence emotional experiences, allowing to judge negative stimuli aesthetically more positively - thus suppressing the immediacy of emotional stimulus content. Copyright © 2014 Elsevier B.V. All rights reserved.
SUMOylation in Drosophila Development

Directory of Open Access Journals (Sweden)

Albert J. Courey

2012-07-01

Full Text Available Small ubiquitin-related modifier (SUMO, an ~90 amino acid ubiquitin-like protein, is highly conserved throughout the eukaryotic domain. Like ubiquitin, SUMO is covalently attached to lysine side chains in a large number of target proteins. In contrast to ubiquitin, SUMO does not have a direct role in targeting proteins for proteasomal degradation. However, like ubiquitin, SUMO does modulate protein function in a variety of other ways. This includes effects on protein conformation, subcellular localization, and protein–protein interactions. Significant insight into the in vivo role of SUMOylation has been provided by studies in Drosophila that combine genetic manipulation, proteomic, and biochemical analysis. Such studies have revealed that the SUMO conjugation pathway regulates a wide variety of critical cellular and developmental processes, including chromatin/chromosome function, eggshell patterning, embryonic pattern formation, metamorphosis, larval and pupal development, neurogenesis, development of the innate immune system, and apoptosis. This review discusses our current understanding of the diverse roles for SUMO in Drosophila development.
Cytochrome P450-Dependent Metabolism of Caffeine in Drosophila melanogaster

Science.gov (United States)

Coelho, Alexandra; Fraichard, Stephane; Le Goff, Gaëlle; Faure, Philippe; Artur, Yves; Ferveur, Jean-François; Heydel, Jean-Marie

2015-01-01

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. PMID:25671424
Cytochrome P450-dependent metabolism of caffeine in Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

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.
Mechanisms underlying stage-1 TRPL channel translocation in Drosophila photoreceptors.

Directory of Open Access Journals (Sweden)

Minh-Ha Lieu

Full Text Available TRP channels function as key mediators of sensory transduction and other cellular signaling pathways. In Drosophila, TRP and TRPL are the light-activated channels in photoreceptors. While TRP is statically localized in the signaling compartment of the cell (the rhabdomere, TRPL localization is regulated by light. TRPL channels translocate out of the rhabdomere in two distinct stages, returning to the rhabdomere with dark-incubation. Translocation of TRPL channels regulates their availability, and thereby the gain of the signal. Little, however, is known about the mechanisms underlying this trafficking of TRPL channels.We first examine the involvement of de novo protein synthesis in TRPL translocation. We feed flies cycloheximide, verify inhibition of protein synthesis, and test for TRPL translocation in photoreceptors. We find that protein synthesis is not involved in either stage of TRPL translocation out of the rhabdomere, but that re-localization to the rhabdomere from stage-1, but not stage-2, depends on protein synthesis. We also characterize an ex vivo eye preparation that is amenable to biochemical and genetic manipulation. We use this preparation to examine mechanisms of stage-1 TRPL translocation. We find that stage-1 translocation is: induced with ATP depletion, unaltered with perturbation of the actin cytoskeleton or inhibition of endocytosis, and slowed with increased membrane sterol content.Our results indicate that translocation of TRPL out of the rhabdomere is likely due to protein transport, and not degradation/re-synthesis. Re-localization from each stage to the rhabdomere likely involves different strategies. Since TRPL channels can translocate to stage-1 in the absence of ATP, with no major requirement of the cytoskeleton, we suggest that stage-1 translocation involves simple diffusion through the apical membrane, which may be regulated by release of a light-dependent anchor in the rhabdomere.
Sigma virus and mutation in Drosophila melanogaster

International Nuclear Information System (INIS)

Paquin, S.L.A.

1977-01-01

- The objectives of these experiments have been (1) to verify and evidence more fully the action of sigma in causing recessive lethal mutation on the X chromosome of Drosophila, both in the male and the female germ line; (2) to extend the study of sigma-induced recessive lethal mutation to the Drosophila autosomes; (3) to explore the possibility that this mutagenesis is site-directed; (4) to study the effects of sigma virus in conjunction with radiation in increasing non-disjunction and dominant lethality. The virus increases the rate of radiation-induced nondisjunction by altering meiotic chromosomal behavior. Percentage of non-disjunction with 500 rads of x-rays in the virus-free flies was 0.176, while in sigma-containing lines it was 0.333. With high doses of either x or neutron radiation, the presence of the virus enhances the frequency of dominant lethality. The difference is especially significant with the fast neutrons. The results indicate that sigma, and presumably other viruses, are indeed environmental mutagens and are, therefore, factors in the rate of background or spontaneous mutation
Combinatorial effect of maytansinol and radiation in Drosophila and human cancer cells

Directory of Open Access Journals (Sweden)

Anthony Edwards

2011-07-01

Combination therapy, in which two or more agents are applied, is more effective than single therapies for combating cancer. For this reason, combinations of chemotherapy with radiation are being explored in clinical trials, albeit with an empirical approach. We developed a screen to identify, from the onset, molecules that act in vivo in conjunction with radiation, using Drosophila as a model. Screens through two small molecule libraries from the NCI Developmental Therapeutics Program yielded microtubule poisons; this class of agents is known to enhance the effect of radiation in mammalian cancer models. Here we report an analysis of one microtubule depolymerizing agent, maytansinol isobutyrate (NSC292222; maytansinol, in Drosophila and in human cancer cells. We find that the effect of maytansinol is p53 dependent in Drosophila cells and human cancer cells, that maytansinol enhances the effect of radiation in both systems, and that the combinatorial effect of drug and radiation is additive. We also uncover a differential sensitivity to maytansinol between Drosophila cells and Drosophila larvae, which illustrates the value of studying cell behavior in the context of a whole organism. On the basis of these results, we propose that Drosophila might be a useful model for unbiased screens through new molecule libraries to find cancer drugs for combination therapy.
Wash functions downstream of Rho1 GTPase in a subset of Drosophila immune cell developmental migrations

Science.gov (United States)

Verboon, Jeffrey M.; Rahe, Travis K.; Rodriguez-Mesa, Evelyn; Parkhurst, Susan M.

2015-01-01

Drosophila immune cells, the hemocytes, undergo four stereotypical developmental migrations to populate the embryo, where they provide immune reconnoitering, as well as a number of non–immune-related functions necessary for proper embryogenesis. Here, we describe a role for Rho1 in one of these developmental migrations in which posteriorly located hemocytes migrate toward the head. This migration requires the interaction of Rho1 with its downstream effector Wash, a Wiskott–Aldrich syndrome family protein. Both Wash knockdown and a Rho1 transgene harboring a mutation that prevents Wash binding exhibit the same developmental migratory defect as Rho1 knockdown. Wash activates the Arp2/3 complex, whose activity is needed for this migration, whereas members of the WASH regulatory complex (SWIP, Strumpellin, and CCDC53) are not. Our results suggest a WASH complex–independent signaling pathway to regulate the cytoskeleton during a subset of hemocyte developmental migrations. PMID:25739458
Failure of irradiated beef and ham to induce genetic aberrations of Drosophila

International Nuclear Information System (INIS)

Mittler, S.

1979-01-01

Ham that had been irradiated by electrons and beef which had been exposed to gamma rays from 60 Co were fed to Drosophila melanogaster to determine whether meat sterilized by these methods would induce genetic aberrations. The results showed that for yB/sc 8 y + Y males, fed on irradiated ham or beef, thermally preserved beef or frozen beef for their entire larval life, there was no significant increase in the loss of X or Y chromosomes or non-disjunction of these chromosomes; there was also no significant increase in any of the broods. Similarly for the Oregon R males, there was no significant increase in yield of sex-linked recessive lethals. Thus feeding of irradiated ham and beef to Drosophila males did not induce significant increases in genetic aberrations. The present findings are discussed in relation to the conflicting results of previous studies. (U.K.)
Phenetic distances in the Drosophila melanogaster-subgroup species and oviposition-site preference for food components

NARCIS (Netherlands)

Bos, M.; Boerema, A.

1981-01-01

Oviposition-site preferences (O.S.P.) have been investigated in females of six sibling species of the Drosophila melanogaster subgroup. O.S.P. were determined for standard food components and yeast genotypes. Females of all species showed a strong preference for complete medium and avoidance of pure
Distinct functions of Crumbs regulating slit diaphragms and endocytosis in Drosophila nephrocytes.

Science.gov (United States)

Hochapfel, Florian; Denk, Lucia; Mendl, Gudrun; Schulze, Ulf; Maaßen, Christine; Zaytseva, Yulia; Pavenstädt, Hermann; Weide, Thomas; Rachel, Reinhard; Witzgall, Ralph; Krahn, Michael P

2017-12-01

Mammalian podocytes, the key determinants of the kidney's filtration barrier, differentiate from columnar epithelial cells and several key determinants of apical-basal polarity in the conventional epithelia have been shown to regulate podocyte morphogenesis and function. However, little is known about the role of Crumbs, a conserved polarity regulator in many epithelia, for slit-diaphragm formation and podocyte function. In this study, we used Drosophila nephrocytes as model system for mammalian podocytes and identified a conserved function of Crumbs proteins for cellular morphogenesis, nephrocyte diaphragm assembly/maintenance, and endocytosis. Nephrocyte-specific knock-down of Crumbs results in disturbed nephrocyte diaphragm assembly/maintenance and decreased endocytosis, which can be rescued by Drosophila Crumbs as well as human Crumbs2 and Crumbs3, which were both expressed in human podocytes. In contrast to the extracellular domain, which facilitates nephrocyte diaphragm assembly/maintenance, the intracellular FERM-interaction motif of Crumbs is essential for regulating endocytosis. Moreover, Moesin, which binds to the FERM-binding domain of Crumbs, is essential for efficient endocytosis. Thus, we describe here a new mechanism of nephrocyte development and function, which is likely to be conserved in mammalian podocytes.

Peptidergic control of a fruit crop pest: the spotted-wing drosophila, Drosophila suzukii

Science.gov (United States)

Neuropeptides play an important role in the regulation of feeding in insects and offer potential targets for the development of new chemicals to control insect pests. A pest that has attracted much recent attention is the highly invasive Drosophila suzukii, a polyphagous pest that can cause serious...
Autoreceptor Control of Peptide/Neurotransmitter Corelease from PDF Neurons Determines Allocation of Circadian Activity in Drosophila

Directory of Open Access Journals (Sweden)

Charles Choi

2012-08-01

Full Text Available Drosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral-ventral pacemaker neurons (LNvs that secrete the neuropeptide PDF (pigment dispersing factor. Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR-expressing dorsal clock neurons in organizing circadian activity. Although LNvs also express functional PDFR, the role of these autoreceptors has remained enigmatic. Here, we show that (1 PDFR activation in LNvs shifts the balance of circadian activity from evening to morning, similar to behavioral responses to summer-like environmental conditions, and (2 this shift is mediated by stimulation of the Gα,s-cAMP pathway and a consequent change in PDF/neurotransmitter corelease from the LNvs. These results suggest another mechanism for environmental control of the allocation of circadian activity and provide new general insight into the role of neuropeptide autoreceptors in behavioral control circuits.
1.8 Å structure of murine GITR ligand dimer expressed in Drosophila melanogaster S2 cells

International Nuclear Information System (INIS)

Chattopadhyay, Kausik; Ramagopal, Udupi A.; Nathenson, Stanley G.; Almo, Steven C.

2009-01-01

1.8 Å X-ray crystal structure of mouse GITRL expressed in D. melanogaster S2 cells shows an identical ‘strand-exchanged’ dimeric assembly similar to that observed previously for the E. coli-expressed protein. Glucocorticoid-induced TNF receptor ligand (GITRL), a prominent member of the TNF superfamily, activates its receptor on both effector and regulatory T cells to generate critical costimulatory signals that have been implicated in a wide range of T-cell immune functions. The crystal structures of murine and human orthologs of GITRL recombinantly expressed in Escherichia coli have previously been determined. In contrast to all classical TNF structures, including the human GITRL structure, murine GITRL demonstrated a unique ‘strand-exchanged’ dimeric organization. Such a novel assembly behavior indicated a dramatic impact on receptor activation as well as on the signaling mechanism associated with the murine GITRL costimulatory system. In this present work, the 1.8 Å resolution crystal structure of murine GITRL expressed in Drosophila melanogaster S2 cells is reported. The eukaryotic protein-expression system allows transport of the recombinant protein into the extracellular culture medium, thus maximizing the possibility of obtaining correctly folded material devoid of any folding/assembly artifacts that are often suspected with E. coli-expressed proteins. The S2 cell-expressed murine GITRL adopts an identical ‘strand-exchanged’ dimeric structure to that observed for the E. coli-expressed protein, thus conclusively demonstrating the novel quaternary structure assembly behavior of murine GITRL
1.8 Å structure of murine GITR ligand dimer expressed in Drosophila melanogaster S2 cells

Energy Technology Data Exchange (ETDEWEB)

Chattopadhyay, Kausik [Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Ramagopal, Udupi A. [Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Nathenson, Stanley G., E-mail: nathenso@aecom.yu.edu [Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Almo, Steven C., E-mail: nathenso@aecom.yu.edu [Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

2009-05-01

1.8 Å X-ray crystal structure of mouse GITRL expressed in D. melanogaster S2 cells shows an identical ‘strand-exchanged’ dimeric assembly similar to that observed previously for the E. coli-expressed protein. Glucocorticoid-induced TNF receptor ligand (GITRL), a prominent member of the TNF superfamily, activates its receptor on both effector and regulatory T cells to generate critical costimulatory signals that have been implicated in a wide range of T-cell immune functions. The crystal structures of murine and human orthologs of GITRL recombinantly expressed in Escherichia coli have previously been determined. In contrast to all classical TNF structures, including the human GITRL structure, murine GITRL demonstrated a unique ‘strand-exchanged’ dimeric organization. Such a novel assembly behavior indicated a dramatic impact on receptor activation as well as on the signaling mechanism associated with the murine GITRL costimulatory system. In this present work, the 1.8 Å resolution crystal structure of murine GITRL expressed in Drosophila melanogaster S2 cells is reported. The eukaryotic protein-expression system allows transport of the recombinant protein into the extracellular culture medium, thus maximizing the possibility of obtaining correctly folded material devoid of any folding/assembly artifacts that are often suspected with E. coli-expressed proteins. The S2 cell-expressed murine GITRL adopts an identical ‘strand-exchanged’ dimeric structure to that observed for the E. coli-expressed protein, thus conclusively demonstrating the novel quaternary structure assembly behavior of murine GITRL.
Drosophila Sulf1 is required for the termination of intestinal stem cell division during regeneration.

Science.gov (United States)

Takemura, Masahiko; Nakato, Hiroshi

2017-01-15

Stem cell division is activated to trigger regeneration in response to tissue damage. The molecular mechanisms by which this stem cell mitotic activity is properly repressed at the end of regeneration are poorly understood. Here, we show that a specific modification of heparan sulfate is crucial for regulating Drosophila intestinal stem cell (ISC) division during normal midgut homeostasis and regeneration. Loss of the extracellular heparan sulfate endosulfatase Sulf1 resulted in increased ISC division during normal homeostasis, which was caused by upregulation of mitogenic signaling including the JAK-STAT, EGFR and Hedgehog pathways. Using a regeneration model, we found that ISCs failed to properly halt division at the termination stage in Sulf1 mutants, showing that Sulf1 is required for terminating ISC division at the end of regeneration. We propose that post-transcriptional regulation of mitogen signaling by heparan sulfate structural modifications provides a new regulatory step for precise temporal control of stem cell activity during regeneration. © 2017. Published by The Company of Biologists Ltd.
Identification of functional elements and regulatory circuits by Drosophila modENCODE

Energy Technology Data Exchange (ETDEWEB)

Roy, Sushmita; Ernst, Jason; Kharchenko, Peter V.; Kheradpour, Pouya; Negre, Nicolas; Eaton, Matthew L.; Landolin, Jane M.; Bristow, Christopher A.; Ma, Lijia; Lin, Michael F.; Washietl, Stefan; Arshinoff, Bradley I.; Ay, Ferhat; Meyer, Patrick E.; Robine, Nicolas; Washington, Nicole L.; Stefano, Luisa Di; Berezikov, Eugene; Brown, Christopher D.; Candeias, Rogerio; Carlson, Joseph W.; Carr, Adrian; Jungreis, Irwin; Marbach, Daniel; Sealfon, Rachel; Tolstorukov, Michael Y.; Will, Sebastian; Alekseyenko, Artyom A.; Artieri, Carlo; Booth, Benjamin W.; Brooks, Angela N.; Dai, Qi; Davis, Carrie A.; Duff, Michael O.; Feng, Xin; Gorchakov, Andrey A.; Gu, Tingting; Henikoff, Jorja G.; Kapranov, Philipp; Li, Renhua; MacAlpine, Heather K.; Malone, John; Minoda, Aki; Nordman, Jared; Okamura, Katsutomo; Perry, Marc; Powell, Sara K.; Riddle, Nicole C.; Sakai, Akiko; Samsonova, Anastasia; Sandler, Jeremy E.; Schwartz, Yuri B.; Sher, Noa; Spokony, Rebecca; Sturgill, David; van Baren, Marijke; Wan, Kenneth H.; Yang, Li; Yu, Charles; Feingold, Elise; Good, Peter; Guyer, Mark; Lowdon, Rebecca; Ahmad, Kami; Andrews, Justen; Berger, Bonnie; Brenner, Steven E.; Brent, Michael R.; Cherbas, Lucy; Elgin, Sarah C. R.; Gingeras, Thomas R.; Grossman, Robert; Hoskins, Roger A.; Kaufman, Thomas C.; Kent, William; Kuroda, Mitzi I.; Orr-Weaver, Terry; Perrimon, Norbert; Pirrotta, Vincenzo; Posakony, James W.; Ren, Bing; Russell, Steven; Cherbas, Peter; Graveley, Brenton R.; Lewis, Suzanna; Micklem, Gos; Oliver, Brian; Park, Peter J.; Celniker, Susan E.; Henikoff, Steven; Karpen, Gary H.; Lai, Eric C.; MacAlpine, David M.; Stein, Lincoln D.; White, Kevin P.; Kellis, Manolis

2010-12-22

of {approx}40% of the protein and nonprotein-coding genes [FlyBase 5.12 (4)] have been determined from cDNA collections (5, 6), manual curation of gene models (7), gene mutations and comprehensive genome-wide RNA interference screens (8-10), and comparative genomic analyses (11, 12). The Drosophila modENCODE project has generated more than 700 data sets that profile transcripts, histone modifications and physical nucleosome properties, general and specific transcription factors (TFs), and replication programs in cell lines, isolated tissues, and whole organisms across several developmental stages (Fig. 1). Here, we computationally integrate these data sets and report (i) improved and additional genome annotations, including full-length proteincoding genes and peptides as short as 21 amino acids; (ii) noncoding transcripts, including 132 candidate structural RNAs and 1608 nonstructural transcripts; (iii) additional Argonaute (Ago)-associated small RNA genes and pathways, including new microRNAs (miRNAs) encoded within protein-coding exons and endogenous small interfering RNAs (siRNAs) from 3-inch untranslated regions; (iv) chromatin 'states' defined by combinatorial patterns of 18 chromatin marks that are associated with distinct functions and properties; (v) regions of high TF occupancy and replication activity with likely epigenetic regulation; (vi)mixed TF and miRNA regulatory networks with hierarchical structure and enriched feed-forward loops; (vii) coexpression- and co-regulation-based functional annotations for nearly 3000 genes; (viii) stage- and tissue-specific regulators; and (ix) predictive models of gene expression levels and regulator function.
Peptidomics and processing of regulatory peptides in the fruit fly Drosophila

Directory of Open Access Journals (Sweden)

Dennis Pauls

2014-06-01

Full Text Available More than a decade has passed since the release of the Drosophila melanogaster genome and the first predictions of fruit fly regulatory peptides (neuropeptides and peptide hormones. Since then, mass spectrometry-based methods have fuelled the chemical characterisation of regulatory peptides, from 7 Drosophila peptides in the pre-genomic area to more than 60 today. We review the development of fruit fly peptidomics, and present a comprehensive list of the regulatory peptides that have been chemically characterised until today. We also summarise the knowledge on peptide processing in Drosophila, which has strongly profited from a combination of MS-based techniques and the genetic tools available for the fruit fly. This combination has a very high potential to study the functional biology of peptide signalling on all levels, especially with the ongoing developments in quantitative MS in Drosophila.
A dopamine receptor contributes to paraquat-induced neurotoxicity in Drosophila

Science.gov (United States)

Cassar, Marlène; Issa, Abdul-Raouf; Riemensperger, Thomas; Petitgas, Céline; Rival, Thomas; Coulom, Hélène; Iché-Torres, Magali; Han, Kyung-An; Birman, Serge

2015-01-01

Long-term exposure to environmental oxidative stressors, like the herbicide paraquat (PQ), has been linked to the development of Parkinson's disease (PD), the most frequent neurodegenerative movement disorder. Paraquat is thus frequently used in the fruit fly Drosophila melanogaster and other animal models to study PD and the degeneration of dopaminergic neurons (DNs) that characterizes this disease. Here, we show that a D1-like dopamine (DA) receptor, DAMB, actively contributes to the fast central nervous system (CNS) failure induced by PQ in the fly. First, we found that a long-term increase in neuronal DA synthesis reduced DAMB expression and protected against PQ neurotoxicity. Secondly, a striking age-related decrease in PQ resistance in young adult flies correlated with an augmentation of DAMB expression. This aging-associated increase in oxidative stress vulnerability was not observed in a DAMB-deficient mutant. Thirdly, targeted inactivation of this receptor in glutamatergic neurons (GNs) markedly enhanced the survival of Drosophila exposed to either PQ or neurotoxic levels of DA, whereas, conversely, DAMB overexpression in these cells made the flies more vulnerable to both compounds. Fourthly, a mutation in the Drosophila ryanodine receptor (RyR), which inhibits activity-induced increase in cytosolic Ca2+, also strongly enhanced PQ resistance. Finally, we found that DAMB overexpression in specific neuronal populations arrested development of the fly and that in vivo stimulation of either DNs or GNs increased PQ susceptibility. This suggests a model for DA receptor-mediated potentiation of PQ-induced neurotoxicity. Further studies of DAMB signaling in Drosophila could have implications for better understanding DA-related neurodegenerative disorders in humans. PMID:25158689
Genetic Determinants of RNA Editing Levels of ADAR Targets in Drosophila melanogaster.

Science.gov (United States)

Kurmangaliyev, Yerbol Z; Ali, Sammi; Nuzhdin, Sergey V

2015-12-12

RNA editing usually affects only a fraction of expressed transcripts and there is a vast amount of variation in editing levels of ADAR (adenosine deaminase, RNA-specific) targets. Here we explore natural genetic variation affecting editing levels of particular sites in 81 natural strains of Drosophila melanogaster. The analysis of associations between editing levels and single-nucleotide polymorphisms allows us to map putative cis-regulatory regions affecting editing of 16 A-to-I editing sites (cis-RNA editing quantitative trait loci or cis-edQTLs, P < 10(-8)). The observed changes in editing levels are validated by independent molecular technique. All identified regulatory variants are located in close proximity of modulated editing sites. Moreover, colocalized editing sites are often regulated by same loci. Similar to expression and splicing QTL studies, the characterization of edQTLs will greatly expand our understanding of cis-regulatory evolution of gene expression. Copyright © 2016 Kurmangaliyev et al.
Genetic Determinants of RNA Editing Levels of ADAR Targets in Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Yerbol Z. Kurmangaliyev

2016-02-01

Full Text Available RNA editing usually affects only a fraction of expressed transcripts and there is a vast amount of variation in editing levels of ADAR (adenosine deaminase, RNA-specific targets. Here we explore natural genetic variation affecting editing levels of particular sites in 81 natural strains of Drosophila melanogaster. The analysis of associations between editing levels and single-nucleotide polymorphisms allows us to map putative cis-regulatory regions affecting editing of 16 A-to-I editing sites (cis-RNA editing quantitative trait loci or cis-edQTLs, P < 10−8. The observed changes in editing levels are validated by independent molecular technique. All identified regulatory variants are located in close proximity of modulated editing sites. Moreover, colocalized editing sites are often regulated by same loci. Similar to expression and splicing QTL studies, the characterization of edQTLs will greatly expand our understanding of cis-regulatory evolution of gene expression.
Neurofibromin Loss of Function Drives Excessive Grooming in Drosophila

Directory of Open Access Journals (Sweden)

Lanikea B. King

2016-04-01

Full Text Available Neurofibromatosis I is a common genetic disorder that results in tumor formation, and predisposes individuals to a range of cognitive/behavioral symptoms, including deficits in attention, visuospatial skills, learning, language development, and sleep, and autism spectrum disorder-like traits. The nf1-encoded neurofibromin protein (Nf1 exhibits high conservation, from the common fruit fly, Drosophila melanogaster, to humans. Drosophila provides a powerful platform to investigate the signaling cascades upstream and downstream of Nf1, and the fly model exhibits similar behavioral phenotypes to mammalian models. In order to understand how loss of Nf1 affects motor behavior in flies, we combined traditional activity monitoring with video analysis of grooming behavior. In nf1 mutants, spontaneous grooming was increased up to 7x. This increase in activity was distinct from previously described dopamine-dependent hyperactivity, as dopamine transporter mutants exhibited slightly decreased grooming. Finally, we found that relative grooming frequencies can be compared in standard activity monitors that measure infrared beam breaks, enabling the use of activity monitors as an automated method to screen for grooming phenotypes. Overall, these data suggest that loss of nf1 produces excessive activity that is manifested as increased grooming, providing a platform to dissect the molecular genetics of neurofibromin signaling across neuronal circuits.
Neurofibromin Loss of Function Drives Excessive Grooming in Drosophila.

Science.gov (United States)

King, Lanikea B; Koch, Marta; Murphy, Keith R; Velazquez, Yoheilly; Ja, William W; Tomchik, Seth M

2016-04-07

Neurofibromatosis I is a common genetic disorder that results in tumor formation, and predisposes individuals to a range of cognitive/behavioral symptoms, including deficits in attention, visuospatial skills, learning, language development, and sleep, and autism spectrum disorder-like traits. The nf1-encoded neurofibromin protein (Nf1) exhibits high conservation, from the common fruit fly, Drosophila melanogaster, to humans. Drosophila provides a powerful platform to investigate the signaling cascades upstream and downstream of Nf1, and the fly model exhibits similar behavioral phenotypes to mammalian models. In order to understand how loss of Nf1 affects motor behavior in flies, we combined traditional activity monitoring with video analysis of grooming behavior. In nf1 mutants, spontaneous grooming was increased up to 7x. This increase in activity was distinct from previously described dopamine-dependent hyperactivity, as dopamine transporter mutants exhibited slightly decreased grooming. Finally, we found that relative grooming frequencies can be compared in standard activity monitors that measure infrared beam breaks, enabling the use of activity monitors as an automated method to screen for grooming phenotypes. Overall, these data suggest that loss of nf1 produces excessive activity that is manifested as increased grooming, providing a platform to dissect the molecular genetics of neurofibromin signaling across neuronal circuits. Copyright © 2016 King et al.
nalyot, a mutation of the Drosophila myb-related Adf1 transcription factor, disrupts synapse formation and olfactory memory.

Science.gov (United States)

DeZazzo, J; Sandstrom, D; de Belle, S; Velinzon, K; Smith, P; Grady, L; DelVecchio, M; Ramaswami, M; Tully, T

2000-07-01

nalyot (nal) is a novel olfactory memory mutant of Drosophila, encoding Adf1, a myb-related transcription factor. Following extended training sessions, Adf1 mutants show normal early memory but defective longterm memory. Adf1 shows widespread spatiotemporal expression, yet mutant alleles reveal no discernible disruptions in gross morphology of the nervous system. Studies at the larval neuromuscular junction, however, reveal a role for Adf1 in the modulation of synaptic growth-in contrast to the role established for dCREB2 in the control of synaptic function (Davis et al., 1996). These findings suggest that Adf1 and dCREB2 regulate distinct transcriptional cascades involved in terminal stages of synapse maturation. More generally, Adf1 provides a novel link between molecular mechanisms of developmental and behavioral plasticity.
Reproduction in Cage Populations of a Polymorphism Regularly Observed in the Natural Populations of DROSOPHILA MELANOGASTER in France.

Science.gov (United States)

Fleuriet, A

1978-04-01

Polymorphism for both alleles of a gene ref(2)P, which is a usual trait of French natural populations of Drosophila melanogaster , can be reproduced in experimental conditions. ref(2)P is a gene for resistance to the hereditary, noncontagious Rhabdovirus sigma, responsible for CO(2) sensitivity in Drosophila melanogaster . The equilibrium frequencies observed in cages are the same as in the wild, whether sigma virus is present or not. The rapid rate of return to these equilibrium frequencies indicates that strong forces, which remain to be determined, are responsible for the maintenance of this polymorphism.
Cold hardiness of winter-acclimated Drosophila suzukii (Diptera: Drosophilidae) adults

Science.gov (United States)

A.R. Stephens; M.K. Asplen; W.D. Hutchison; Robert C. Venette

2015-01-01

Drosophila suzukii Matsumura, often called spotted wing drosophila, is an exotic vinegar fly that is native to Southeast Asia and was first detected in the continental United States in 2008. Previous modeling studies have suggested that D. suzukii might not survive in portions of the northern United States or southern Canada...
Regulation of lifespan, metabolism, and stress responses by the Drosophila SH2B protein, Lnk.

Directory of Open Access Journals (Sweden)

Cathy Slack

2010-03-01

Full Text Available Drosophila Lnk is the single ancestral orthologue of a highly conserved family of structurally-related intracellular adaptor proteins, the SH2B proteins. As adaptors, they lack catalytic activity but contain several protein-protein interaction domains, thus playing a critical role in signal transduction from receptor tyrosine kinases to form protein networks. Physiological studies of SH2B function in mammals have produced conflicting data. However, a recent study in Drosophila has shown that Lnk is an important regulator of the insulin/insulin-like growth factor (IGF-1 signaling (IIS pathway during growth, functioning in parallel to the insulin receptor substrate, Chico. As this pathway also has an evolutionary conserved role in the determination of organism lifespan, we investigated whether Lnk is required for normal lifespan in Drosophila. Phenotypic analysis of mutants for Lnk revealed that loss of Lnk function results in increased lifespan and improved survival under conditions of oxidative stress and starvation. Starvation resistance was found to be associated with increased metabolic stores of carbohydrates and lipids indicative of impaired metabolism. Biochemical and genetic data suggest that Lnk functions in both the IIS and Ras/Mitogen activated protein Kinase (MapK signaling pathways. Microarray studies support this model, showing transcriptional feedback onto genes in both pathways as well as indicating global changes in both lipid and carbohydrate metabolism. Finally, our data also suggest that Lnk itself may be a direct target of the IIS responsive transcription factor, dFoxo, and that dFoxo may repress Lnk expression. We therefore describe novel functions for a member of the SH2B protein family and provide the first evidence for potential mechanisms of SH2B regulation. Our findings suggest that IIS signaling in Drosophila may require the activity of a second intracellular adaptor, thereby yielding fundamental new insights into the
Cytochrome c oxidase loses catalytic activity and structural integrity during the aging process in Drosophila melanogaster

Energy Technology Data Exchange (ETDEWEB)

Ren, Jian-Ching; Rebrin, Igor [Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033 (United States); Klichko, Vladimir; Orr, William C. [Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275 (United States); Sohal, Rajindar S., E-mail: sohal@usc.edu [Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033 (United States)

2010-10-08

Research highlights: {yields} Cytochrome c oxidase loses catalytic activity during the aging process. {yields} Abundance of seven nuclear-encoded subunits of cytochrome c oxidase decreased with age in Drosophila. {yields} Cytochrome c oxidase is specific intra-mitochondrial site of age-related deterioration. -- Abstract: The hypothesis, that structural deterioration of cytochrome c oxidase (CcO) is a causal factor in the age-related decline in mitochondrial respiratory activity and an increase in H{sub 2}O{sub 2} generation, was tested in Drosophila melanogaster. CcO activity and the levels of seven different nuclear DNA-encoded CcO subunits were determined at three different stages of adult life, namely, young-, middle-, and old-age. CcO activity declined progressively with age by 33%. Western blot analysis, using antibodies specific to Drosophila CcO subunits IV, Va, Vb, VIb, VIc, VIIc, and VIII, indicated that the abundance these polypeptides decreased, ranging from 11% to 40%, during aging. These and previous results suggest that CcO is a specific intra-mitochondrial site of age-related deterioration, which may have a broad impact on mitochondrial physiology.
Cytochrome c oxidase loses catalytic activity and structural integrity during the aging process in Drosophila melanogaster

International Nuclear Information System (INIS)

Ren, Jian-Ching; Rebrin, Igor; Klichko, Vladimir; Orr, William C.; Sohal, Rajindar S.

2010-01-01

Research highlights: → Cytochrome c oxidase loses catalytic activity during the aging process. → Abundance of seven nuclear-encoded subunits of cytochrome c oxidase decreased with age in Drosophila. → Cytochrome c oxidase is specific intra-mitochondrial site of age-related deterioration. -- Abstract: The hypothesis, that structural deterioration of cytochrome c oxidase (CcO) is a causal factor in the age-related decline in mitochondrial respiratory activity and an increase in H 2 O 2 generation, was tested in Drosophila melanogaster. CcO activity and the levels of seven different nuclear DNA-encoded CcO subunits were determined at three different stages of adult life, namely, young-, middle-, and old-age. CcO activity declined progressively with age by 33%. Western blot analysis, using antibodies specific to Drosophila CcO subunits IV, Va, Vb, VIb, VIc, VIIc, and VIII, indicated that the abundance these polypeptides decreased, ranging from 11% to 40%, during aging. These and previous results suggest that CcO is a specific intra-mitochondrial site of age-related deterioration, which may have a broad impact on mitochondrial physiology.
The role of abdominal compliance, the neglected parameter in critically ill patients - a consensus review of 16. Part 1: definitions and pathophysiology.

Science.gov (United States)

Malbrain, Manu L N G; Roberts, Derek J; De Laet, Inneke; De Waele, Jan J; Sugrue, Michael; Schachtrupp, Alexander; Duchesne, Juan; Van Ramshorst, Gabrielle; De Keulenaer, Bart; Kirkpatrick, Andrew W; Ahmadi-Noorbakhsh, Siavash; Mulier, Jan; Ivatury, Rao; Pracca, Francisco; Wise, Robert; Pelosi, Paolo

2014-01-01

Over the last few decades, increasing attention has been paid to understanding the pathophysiology, aetiology, prognosis, and treatment of elevated intra-abdominal pressure (IAP) in trauma, surgical, and medical patients. However, there is presently a relatively poor understanding of intra-abdominal volume (IAV) and the relationship between IAV and IAP (i.e. abdominal compliance). Consensus definitions on Cab were discussed during the 5th World Congress on Abdominal Compartment Syndrome and a writing committee was formed to develop this article. During the writing process, a systematic and structured Medline and PubMed search was conducted to identify relevant studies relating to the topic. According to the recently updated consensus definitions of the World Society on Abdominal Compartment Syndrome (WSACS), abdominal compliance (Cab) is defined as a measure of the ease of abdominal expansion, which is determined by the elasticity of the abdominal wall and diaphragm. It should be expressed as the change in IAV per change in IAP (mL [mm Hg]⁻¹). Importantly, Cab is measured differently than IAP and the abdominal wall (and its compliance) is only a part of the total abdominal pressure-volume (PV) relationship. During an increase in IAV, different phases are encountered: the reshaping, stretching, and pressurisation phases. The first part of this review article starts with a comprehensive list of the different definitions related to IAP (at baseline, during respiratory variations, at maximal IAV), IAV (at baseline, additional volume, abdominal workspace, maximal and unadapted volume), and abdominal compliance and elastance (i.e. the relationship between IAV and IAP). An historical background on the pathophysiology related to IAP, IAV and Cab follows this. Measurement of Cab is difficult at the bedside and can only be done in a case of change (removal or addition) in IAV. The Cab is one of the most neglected parameters in critically ill patients, although it plays a
P1 interneurons promote a persistent internal state that enhances inter-male aggression in Drosophila

Science.gov (United States)

Hoopfer, Eric D; Jung, Yonil; Inagaki, Hidehiko K; Rubin, Gerald M; Anderson, David J

2015-01-01

How brains are hardwired to produce aggressive behavior, and how aggression circuits are related to those that mediate courtship, is not well understood. A large-scale screen for aggression-promoting neurons in Drosophila identified several independent hits that enhanced both inter-male aggression and courtship. Genetic intersections revealed that 8-10 P1 interneurons, previously thought to exclusively control male courtship, were sufficient to promote fighting. Optogenetic experiments indicated that P1 activation could promote aggression at a threshold below that required for wing extension. P1 activation in the absence of wing extension triggered persistent aggression via an internal state that could endure for minutes. High-frequency P1 activation promoted wing extension and suppressed aggression during photostimulation, whereas aggression resumed and wing extension was inhibited following photostimulation offset. Thus, P1 neuron activation promotes a latent, internal state that facilitates aggression and courtship, and controls the overt expression of these social behaviors in a threshold-dependent, inverse manner. DOI: http://dx.doi.org/10.7554/eLife.11346.001 PMID:26714106

Genome-Wide Approaches to Drosophila Heart Development

Directory of Open Access Journals (Sweden)

Manfred Frasch

2016-05-01

Full Text Available The development of the dorsal vessel in Drosophila is one of the first systems in which key mechanisms regulating cardiogenesis have been defined in great detail at the genetic and molecular level. Due to evolutionary conservation, these findings have also provided major inputs into studies of cardiogenesis in vertebrates. Many of the major components that control Drosophila cardiogenesis were discovered based on candidate gene approaches and their functions were defined by employing the outstanding genetic tools and molecular techniques available in this system. More recently, approaches have been taken that aim to interrogate the entire genome in order to identify novel components and describe genomic features that are pertinent to the regulation of heart development. Apart from classical forward genetic screens, the availability of the thoroughly annotated Drosophila genome sequence made new genome-wide approaches possible, which include the generation of massive numbers of RNA interference (RNAi reagents that were used in forward genetic screens, as well as studies of the transcriptomes and proteomes of the developing heart under normal and experimentally manipulated conditions. Moreover, genome-wide chromatin immunoprecipitation experiments have been performed with the aim to define the full set of genomic binding sites of the major cardiogenic transcription factors, their relevant target genes, and a more complete picture of the regulatory network that drives cardiogenesis. This review will give an overview on these genome-wide approaches to Drosophila heart development and on computational analyses of the obtained information that ultimately aim to provide a description of this process at the systems level.
Identification of Compounds That Inhibit IGF-I Signaling in Hyperglycemia

Directory of Open Access Journals (Sweden)

Laura A. Maile

2009-01-01

Full Text Available Increased responsiveness of vascular cells to the growth factor IGF-I has been implicated in complications associated with diabetes. Here we describe the development of an assay and screening of a library of compounds for their ability to accelerate cleavage of the transmembrane protein integrin-associated protein (IAP thereby disrupting the association between IAP and SHPS-1 which we have shown as critical for the enhanced response of vascular cells to IGF-I. The cell-based ELISA utilizes an antibody that specifically detects cleaved, but not intact, IAP. Of the 1040 compounds tested, 14 were considered active by virtue of their ability to stimulate an increase in antibody-binding indicative of IAP cleavage. In experiments with smooth muscle and retinal endothelial cell cultures in hyperglycemic conditions, each active compound was shown to accelerate the cleavage of IAP, and this was associated with a decrease in IAP association with SHPS-1 as determined by coimmunoprecipitation of the proteins from cell lysates. As a consequence of the acceleration in IAP cleavage, the compounds were shown to inhibit IGF-I-stimulated phosphorylation of key signaling molecules including Shc and ERK1/2, and this in turn was associated with a decrease in IGF-I-stimulated cell proliferation. Identification of these compounds that utilize this mechanism has the potential to yield novel therapeutic approaches for the prevention and treatment of vascular complications associated with diabetes.
Adaptive evolution of relish, a Drosophila NF-kappaB/IkappaB protein.

OpenAIRE

Begun, D J; Whitley, P

2000-01-01

NF-kappaB and IkappaB proteins have central roles in regulation of inflammation and innate immunity in mammals. Homologues of these proteins also play an important role in regulation of the Drosophila immune response. Here we present a molecular population genetic analysis of Relish, a Drosophila NF-kappaB/IkappaB protein, in Drosophila simulans and D. melanogaster. We find strong evidence for adaptive protein evolution in D. simulans, but not in D. melanogaster. The adaptive evolution appear...
Drosophila MOF controls Checkpoint protein2 and regulates genomic stability during early embryogenesis

Directory of Open Access Journals (Sweden)

Pushpavalli Sreerangam NCVL

2013-01-01

Full Text Available Abstract Background In Drosophila embryos, checkpoints maintain genome stability by delaying cell cycle progression that allows time for damage repair or to complete DNA synthesis. Drosophila MOF, a member of MYST histone acetyl transferase is an essential component of male X hyperactivation process. Until recently its involvement in G2/M cell cycle arrest and defects in ionizing radiation induced DNA damage pathways was not well established. Results Drosophila MOF is highly expressed during early embryogenesis. In the present study we show that haplo-insufficiency of maternal MOF leads to spontaneous mitotic defects like mitotic asynchrony, mitotic catastrophe and chromatid bridges in the syncytial embryos. Such abnormal nuclei are eliminated and digested in the yolk tissues by nuclear fall out mechanism. MOF negatively regulates Drosophila checkpoint kinase 2 tumor suppressor homologue. In response to DNA damage the checkpoint gene Chk2 (Drosophila mnk is activated in the mof mutants, there by causing centrosomal inactivation suggesting its role in response to genotoxic stress. A drastic decrease in the fall out nuclei in the syncytial embryos derived from mof1/+; mnkp6/+ females further confirms the role of DNA damage response gene Chk2 to ensure the removal of abnormal nuclei from the embryonic precursor pool and maintain genome stability. The fact that mof mutants undergo DNA damage has been further elucidated by the increased number of single and double stranded DNA breaks. Conclusion mof mutants exhibited genomic instability as evidenced by the occurance of frequent mitotic bridges in anaphase, asynchronous nuclear divisions, disruption of cytoskeleton, inactivation of centrosomes finally leading to DNA damage. Our findings are consistent to what has been reported earlier in mammals that; reduced levels of MOF resulted in increased genomic instability while total loss resulted in lethality. The study can be further extended using
Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory.

Science.gov (United States)

Shuai, Yichun; Hirokawa, Areekul; Ai, Yulian; Zhang, Min; Li, Wanhe; Zhong, Yi

2015-12-01

Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-β'1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts.
Male recombination in Brazilian populations of Drosophila ananassae.

Science.gov (United States)

Goñi, Beatriz; Matsuda, Muneo; Tobari, Yoshiko N

2016-07-01

With few exceptions, spontaneous crossing over does not normally occur in male Drosophila. Drosophila ananassae males show considerable amounts of crossing over. In wild males of D. ananassae from Asian (2008) and Brazilian populations (1986 and 2007) variable frequencies of meiotic crossing over, estimated from chiasmata counts, suggested the existence of factors controlling male crossing over in these populations. To corroborate for such prediction, we present data on spontaneous recombination in F1 males of D. ananassae heterozygous for chromosomes of the same Brazilian populations (1986) and marker chromosomes using three testers stocks. Mean recombination value was low, although high variability existed between individual frequencies. Recombination frequencies between lines in each tester stock were not significantly different, excepting when the 3ple-px and 3ple-cy testers were compared (p recombination in chromosomes 2 and 3 in F1 males tested with e(65) se; bri ru was not related, suggesting they are under independent genetic control. Our data are consistent with proposed genetic factors controlling male crossing over in the tester stocks and to the presence of enhancers and suppressors of male crossing over segregating in the Brazilian populations (1986).
Mutation induction in repair-deficient strains of Drosophila

International Nuclear Information System (INIS)

Wuergler, F.E.; Graf, U.

1980-01-01

Experimental evidence indicates a polygenic control of mutagenesis in Drosophila melanogaster. In oocytes chromosome aberrations detected as half-translocations or dominant lethals depend on a repair system which in a number of genetically nonrelated strains shows different repair capacities. Sister chromatid exchanges are easily studied as ring chromosome losses. They develop through a genotype controlled mechanism from, premutational lesions. Stocks with particular pairs of third chromosomes were discovered in which increased sensitivity of larvae to the toxic effects of a monofunctional alkylating agent correlates with high frequencies of x-ray induced SCE's. Sex-linked mutagen-sensitive mutants could be shown to control mutation fixation: pronounced maternal effects were found when sperm carrying particular types of premutational lesions were introduced into different types of mutant oocytes. The mutant mus(1)101D1 was found to be unable to process lesions induced by the crosslinking agent nitrogen mustard into point mutations. Alkylation damage leads to increased point mutation frequencies in the excision repair deficient mutant mei-9L1, but to reduced frequencies in the post-replication repair deficient mutant mei-41D5. It became clear that the study of maternal effects on mutagenized sperm represents an efficient tool to analyze the gentic control of mutagenesis in the eukaryotic genome of Drosophila melanogaster
Simple Y-Autosomal Incompatibilities Cause Hybrid Male Sterility in Reciprocal Crosses Between Drosophila virilis and D. americana

OpenAIRE

Sweigart, Andrea L.

2010-01-01

Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F1 hybrid males are perfectly fertile. Second, later generation (backcross and F2) hybrid male sterility ...
Longevity and the stress response in Drosophila

DEFF Research Database (Denmark)

Vermeulen, Corneel J.; Loeschcke, Volker

2007-01-01

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...... research. Keywords: Ageing; Stress response; Hsp; Drosophila; Stress......The concept that lifespan is a function of the capacity to withstand extrinsic stress is very old. In concordance with this, long-lived individuals often have increased resistance against a variety of stresses throughout life. Genes underlying the stress response may therefore have the ability...
Mutagenic effects of irradiated glucose in Drosophila melanogaster

International Nuclear Information System (INIS)

Varma, M.B.; Rao, K.P.; Nandan, S.D.; Rao, M.S.

1982-01-01

The mutagenic effects of irradiated glucose were studied using the sex-linked recessive lethal test in Drosophila melanogaster. Oregon K males of D. melanogaster reared on a medium containing 20 or 40% glucose irradiated with a dose of 0.02, 0.10, 0.20, 2 or 5 Mrad #betta#-rays were scored for the induction of sex-linked recessive lethals. The results showed no significant increase in the frequency of X-lethals in Drosophila at any of the dose levels. (author)
Consequences of outbreeding on phenotypic plasticity in Drosophila mercatorum wings

DEFF Research Database (Denmark)

Krag, Kristian; Thomsen, Hans Paarup; Faurby, Søren

2009-01-01

A multivariate morphometric investigation was conducted on wings of two parthenogenetic Drosophila mercatorum strains and offspring (F1) of crosses between these parthenogenetic strains with highly inbred sexual individuals of the same species. The parental flies and F1 offspring were reared at t...
The role of reduced oxygen in the developmental physiology of growth and metamorphosis initiation in Drosophila

Science.gov (United States)

Rearing oxygen level is known to affect final body size in a variety of insects, but the physiological mechanisms by which oxygen affects size are incompletely understood. In Manduca and Drosophila, the larval size at which metamorphosis is initiated largely determines adult size, and metamorphosis ...
Border Structure of Intercalary Heterochromatin Bands of Drosophila melanogaster Polytene Chromosomes.

Science.gov (United States)

Khoroshko, V A; Zykova, T Yu; Popova, O O; Zhimulev, I F

2018-03-01

The precise genomic localization of the borders of 62 intercalary heterochromatin bands in Drosophila polytene chromosomes was determined. A new type of bands containing chromatin of different states was identified. This type is a combination of the gray band and the intercalary heterochromatin band, creating a genetic structure that with a light microscope is identified as a continuous band. The border structure of such bands includes the coding regions of genes with ubiquitous activity.
Comparative evaluation of the genomes of three common Drosophila-associated bacteria

Directory of Open Access Journals (Sweden)

Kristina Petkau

2016-09-01

Full Text Available Drosophila melanogaster is an excellent model to explore the molecular exchanges that occur between an animal intestine and associated microbes. Previous studies in Drosophila uncovered a sophisticated web of host responses to intestinal bacteria. The outcomes of these responses define critical events in the host, such as the establishment of immune responses, access to nutrients, and the rate of larval development. Despite our steady march towards illuminating the host machinery that responds to bacterial presence in the gut, there are significant gaps in our understanding of the microbial products that influence bacterial association with a fly host. We sequenced and characterized the genomes of three common Drosophila-associated microbes: Lactobacillus plantarum, Lactobacillus brevis and Acetobacter pasteurianus. For each species, we compared the genomes of Drosophila-associated strains to the genomes of strains isolated from alternative sources. We found that environmental Lactobacillus strains readily associated with adult Drosophila and were similar to fly isolates in terms of genome organization. In contrast, we identified a strain of A. pasteurianus that apparently fails to associate with adult Drosophila due to an inability to grow on fly nutrient food. Comparisons between association competent and incompetent A. pasteurianus strains identified a short list of candidate genes that may contribute to survival on fly medium. Many of the gene products unique to fly-associated strains have established roles in the stabilization of host-microbe interactions. These data add to a growing body of literature that examines the microbial perspective of host-microbe relationships.
Drosophila Vps13 Is Required for Protein Homeostasis in the Brain.

Directory of Open Access Journals (Sweden)

Jan J Vonk

Full Text Available Chorea-Acanthocytosis is a rare, neurodegenerative disorder characterized by progressive loss of locomotor and cognitive function. It is caused by loss of function mutations in the Vacuolar Protein Sorting 13A (VPS13A gene, which is conserved from yeast to human. The consequences of VPS13A dysfunction in the nervous system are still largely unspecified. In order to study the consequences of VPS13A protein dysfunction in the ageing central nervous system we characterized a Drosophila melanogaster Vps13 mutant line. The Drosophila Vps13 gene encoded a protein of similar size as human VPS13A. Our data suggest that Vps13 is a peripheral membrane protein located to endosomal membranes and enriched in the fly head. Vps13 mutant flies showed a shortened life span and age associated neurodegeneration. Vps13 mutant flies were sensitive to proteotoxic stress and accumulated ubiquitylated proteins. Levels of Ref(2P, the Drosophila orthologue of p62, were increased and protein aggregates accumulated in the central nervous system. Overexpression of the human Vps13A protein in the mutant flies partly rescued apparent phenotypes. This suggests a functional conservation of human VPS13A and Drosophila Vps13. Our results demonstrate that Vps13 is essential to maintain protein homeostasis in the larval and adult Drosophila brain. Drosophila Vps13 mutants are suitable to investigate the function of Vps13 in the brain, to identify genetic enhancers and suppressors and to screen for potential therapeutic targets for Chorea-Acanthocytosis.
Amplification of neural stem cell proliferation by intermediate progenitor cells in Drosophila brain development

Directory of Open Access Journals (Sweden)

Bello Bruno C

2008-02-01

Full Text Available Abstract Background In the mammalian brain, neural stem cells divide asymmetrically and often amplify the number of progeny they generate via symmetrically dividing intermediate progenitors. Here we investigate whether specific neural stem cell-like neuroblasts in the brain of Drosophila might also amplify neuronal proliferation by generating symmetrically dividing intermediate progenitors. Results Cell lineage-tracing and genetic marker analysis show that remarkably large neuroblast lineages exist in the dorsomedial larval brain of Drosophila. These lineages are generated by brain neuroblasts that divide asymmetrically to self renew but, unlike other brain neuroblasts, do not segregate the differentiating cell fate determinant Prospero to their smaller daughter cells. These daughter cells continue to express neuroblast-specific molecular markers and divide repeatedly to produce neural progeny, demonstrating that they are proliferating intermediate progenitors. The proliferative divisions of these intermediate progenitors have novel cellular and molecular features; they are morphologically symmetrical, but molecularly asymmetrical in that key differentiating cell fate determinants are segregated into only one of the two daughter cells. Conclusion Our findings provide cellular and molecular evidence for a new mode of neurogenesis in the larval brain of Drosophila that involves the amplification of neuroblast proliferation through intermediate progenitors. This type of neurogenesis bears remarkable similarities to neurogenesis in the mammalian brain, where neural stem cells as primary progenitors amplify the number of progeny they generate through generation of secondary progenitors. This suggests that key aspects of neural stem cell biology might be conserved in brain development of insects and mammals.
Pluripotency and a secretion mechanism of Drosophila transglutaminase.

Science.gov (United States)

Shibata, Toshio; Kawabata, Shun-Ichiro

2018-03-01

Transglutaminase (TG) catalyses the formation of an isopeptide bond between glutamine and lysine residues and amine incorporation into specific glutamine residues. TG is conserved in all metazoans and functions both intracellularly and extracellularly. Here we review the existing knowledge of Drosophila TG with an emphasis on its pluripotency: Drosophila TG (i) plays a key role in cuticular morphogenesis, haemolymph coagulation, and entrapment against invading pathogens, (ii) suppresses the immune deficiency pathway to enable immune tolerance against commensal bacteria through the incorporation of polyamines into the nuclear factor-κB-like transcription factor Relish as well as through the protein-protein cross-linking of Relish, (iii) forms a physical matrix in the gut through cross-linking of chitin-binding proteins and (iv) is involved in the maintenance of homeostasis in microbiota in the gut. Moreover, we review the evidence that TG-A, one of alternative splicing-derived isoforms of Drosophila TG, is secreted through an endoplasmic reticulum/Golgi-independent pathway involving exosomes and fatty acylations.
Measurement of lung water with SPECT

International Nuclear Information System (INIS)

Chu, R.Y.L.; Ficken, V.J.; Ekeh, S.U.; Ryals, C.J.; Allen, E.W.; Basmadjian, G.

1990-01-01

This paper investigates the use of iodoantipyrine (IAP) labeled with radioactive iodine (I-123) and single photon emission tomography (SPECT) to measure lung water. I-123 IAP was injected intravenously to six New Zealand White rabbits under anesthesia. After 1 hour, Tc-99m macroaggregates of albumin (MAA) were injected. SPECT imaging was performed in dual-energy mode. After a blood sample was drawn, the animals were sacrificed, and the lungs were removed. Blood samples were assayed for radioactivity. The lungs were weighed, dried, and weighted again to determine water content. The product of area defined by MAA in a tomogram and IAP count rate of central pixels of that region in the corresponding tomogram was taken as the relative amount of IAP in each lung
Extracellular matrix and its receptors in Drosophila neural development

Science.gov (United States)

Broadie, Kendal; Baumgartner, Stefan; Prokop, Andreas

2011-01-01

Extracellular matrix (ECM) and matrix receptors are intimately involved in most biological processes. The ECM plays fundamental developmental and physiological roles in health and disease, including processes underlying the development, maintenance and regeneration of the nervous system. To understand the principles of ECM-mediated functions in the nervous system, genetic model organisms like Drosophila provide simple, malleable and powerful experimental platforms. This article provides an overview of ECM proteins and receptors in Drosophila. It then focuses on their roles during three progressive phases of neural development: 1) neural progenitor proliferation, 2) axonal growth and pathfinding and 3) synapse formation and function. Each section highlights known ECM and ECM-receptor components and recent studies done in mutant conditions to reveal their in vivo functions, all illustrating the enormous opportunities provided when merging work on the nervous system with systematic research into ECM-related gene functions. PMID:21688401
miR-11 regulates pupal size of Drosophila melanogaster via directly targeting Ras85D.

Science.gov (United States)

Li, Yao; Li, Shengjie; Jin, Ping; Chen, Liming; Ma, Fei

2017-01-01

MicroRNAs play diverse roles in various physiological processes during Drosophila development. In the present study, we reported that miR-11 regulates pupal size during Drosophila metamorphosis via targeting Ras85D with the following evidences: pupal size was increased in the miR-11 deletion mutant; restoration of miR-11 in the miR-11 deletion mutant rescued the increased pupal size phenotype observed in the miR-11 deletion mutant; ectopic expression of miR-11 in brain insulin-producing cells (IPCs) and whole body shows consistent alteration of pupal size; Dilps and Ras85D expressions were negatively regulated by miR-11 in vivo; miR-11 targets Ras85D through directly binding to Ras85D 3'-untranslated region in vitro; removal of one copy of Ras85D in the miR-11 deletion mutant rescued the increased pupal size phenotype observed in the miR-11 deletion mutant. Thus, our current work provides a novel mechanism of pupal size determination by microRNAs during Drosophila melanogaster metamorphosis. Copyright © 2017 the American Physiological Society.

Some links on this page may take you to non-federal websites. Their policies may differ from this site.