Removal ratio of gaseous toluene and xylene transported from air to root zone via the stem by indoor plants.

PubMed

Kim, K J; Kim, H J; Khalekuzzaman, M; Yoo, E H; Jung, H H; Jang, H S

2016-04-01

This work was designed to investigate the removal efficiency as well as the ratios of toluene and xylene transported from air to root zone via the stem and by direct diffusion from the air into the medium. Indoor plants (Schefflera actinophylla and Ficus benghalensis) were placed in a sealed test chamber. Shoot or root zone were sealed with a Teflon bag, and gaseous toluene and xylene were exposed. Removal efficiency of toluene and total xylene (m, p, o) was 13.3 and 7.0 μg·m(-3)·m(-2) leaf area over a 24-h period in S. actinophylla, and was 13.0 and 7.3 μg·m(-3)·m(-2) leaf area in F. benghalensis. Gaseous toluene and xylene in a chamber were absorbed through leaf and transported via the stem, and finally reached to root zone, and also transported by direct diffusion from the air into the medium. Toluene and xylene transported via the stem was decreased with time after exposure. Xylene transported via the stem was higher than that by direct diffusion from the air into the medium over a 24-h period. The ratios of toluene transported via the stem versus direct diffusion from the air into the medium were 46.3 and 53.7% in S. actinophylla, and 46.9 and 53.1% in F. benghalensis, for an average of 47 and 53% for both species. The ratios of m,p-xylene transported over 3 to 9 h via the stem versus direct diffusion from the air into the medium was 58.5 and 41.5% in S. actinophylla, and 60.7 and 39.3% in F. benghalensis, for an average of 60 and 40% for both species, whereas the ratios of o-xylene transported via the stem versus direct diffusion from the air into the medium were 61 and 39%. Both S. actinophylla and F. benghalensis removed toluene and xylene from the air. The ratios of toluene and xylene transported from air to root zone via the stem were 47 and 60 %, respectively. This result suggests that root zone is a significant contributor to gaseous toluene and xylene removal, and transported via the stem plays an important role in this process.

Behavioral effects of environmental chemicals in rats exposed in an inhalational behavioral chamber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, T.K.; Copeland, R.L. Jr.; Pradhan, S.N.

1986-03-01

In order to study the behavioral toxicity of environmental chemicals at low concentrations (conc.), effects of inhalation of xylene or toluene were investigated in rats on fixed-ratio (FR24) liquid (5% sucrose) reinforcement (RIF) and intracranial self-stimulation (SS, with electrodes in A10 area) while being exposed to the solvent vapor in an inhalational behavioral chamber designed in the laboratory. While exposed to 3 graded conc. of xylene vapor for 2 hr each during 6 hr sessions, decreases in RIF was observed during 1,3 and 5 hr. Levels of behavioral performance were improved during 2,4 and 6 hr indicating development of tolerance.more » Similar effects were also observed in experiments (expt.) with toluene, which appeared to be somewhat less potent. Exposed to graded conc. of xylene for 2 hr each on separate days, rats also showed similar RIF decreases which appeared to be conc.-dependent. Prolonged (5hr) exposure to the lowest effective conc. of xylene used (139 ppm) which showed slight or no effect in these expt. decreased RIF only at hr 1 and hr 2 following which RIF improved further showing development of tolerance. Similar decreases in RIF was also observed at middle and high xylene conc. in ss expt. Thus, behavioral depression and subsequent development of tolerance were observed in these expt. with the industrial solvents.« less

Alternative to xylene as a clearing agent in histopathology

PubMed Central

Alwahaibi, Nasar; Aljaradi, Shaima; Alazri, Horiyah

2018-01-01

INTRODUCTION: Clearing is an essential step in processing tissue for light microscopy. Xylene is the clearing agent used most commonly worldwide. Xylene is toxic and therefore a threat to personnel working in histopathology laboratories. We evaluated a safer alternative clearing agent for use in the histopathology laboratory. MATERIALS AND METHODS: We used 230 formalin-fixed, paraffin-embedded tissue blocks from 19 different tissues. Half of the specimens were processed using xylene and half were processed using UltraClear™. Tissues were evaluated for eight parameters: sectioning, nuclear staining, cytoplasmic staining, overall cell morphology, clarity of staining, uniformity of staining, quality of immunohistochemistry (IHC), and cost. RESULTS: Both UltraClear™ and xylene processed sections scored 100% for IHC. Sections processed using UltraClear™ were easy to cut (81.7%) as were xylene processed sections (96.5%). UltraClear™ processed sections showed 67%, 60.9%, 52.2%, 63.5%, and 67% for nuclear staining, cytoplasmic staining, cell morphology, clarity of staining, and uniformity of staining, respectively. UltraClear™ is twice as expensive as xylene. We found that tissues processed using UltraClear™ were easy to cut and worked well for both hematoxylin and eosin and IHC staining. CONCLUSION: UltraClear™ is less toxic, less flammable, friendlier to the environment, and easy to handle, but it is two times expensive than xylene. The findings of this study recommend the use of UltraClear™ solution as a routine clearing agent in histopathology laboratories. However, further studies are required. PMID:29692586

Behavioral Teratogenesis in Drosophila melanogaster.

PubMed

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.

Metal-Organic Frameworks for Resonant-Gravimetric Detection of Trace-Level Xylene Molecules.

PubMed

Xu, Tao; Xu, Pengcheng; Zheng, Dan; Yu, Haitao; Li, Xinxin

2016-12-20

As one of typical VOCs, xylene is seriously harmful to human health. Nowadays, however, there is really lack of portable sensing method to directly detect environmental xylene that has chemical inertness. Especially when the concentration of xylene is lower than the human olfactory threshold of 470 ppb, people are indeed hard to be aware of and avoid this harmful vapor. Herein the metal-organic framework (MOF) of HKUST-1 is first explored for sensing to the nonpolar molecule of p-xylene. And the sensing mechanism is identified that is via host-guest interaction of MOF with xylene molecule. By loading MOFs on mass-gravimetric resonant-cantilevers, sensing experiments for four MOFs of MOF-5, HKUST-1, ZIF-8, and MOF-177 approve that HKUST-1 has the highest sensitivity to p-xylene. The resonant-gravimetric sensing experiments with our HKUST-1 based sensors have demonstrated that trace-level p-xylene of 400 ppb can be detected that is lower than the human olfactory threshold of 470 ppb. We analyze that the specificity of HKUST-1 to xylene comes from Cu 2+ -induced moderate Lewis acidity and the "like dissolves like" interaction of the benzene ring. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is used to elucidate the adsorbing/sensing mechanism of HKUST-1 to p-xylene, where p-xylene adsorbing induced blue-shift phenomenon is observed that confirms the sensing mechanism. Our study also indicates that the sensor shows good selectivity to various kinds of common interfering gases. And the long-term repeatability and stability of the sensing material are also approved for the usage/storage period of two months. This research approves that the MOF materials exhibit potential usages for high performance chemical sensors applications.

Xylenes transformation over zeolites ZSM-5 ruled by acidic properties

NASA Astrophysics Data System (ADS)

Gołąbek, Kinga; Tarach, Karolina A.; Góra-Marek, Kinga

2018-03-01

The studies presented in this work offer an insight into xylene isomerization process, followed by 2D COS analysis, in the terms of different acidity of microporous zeolites ZSM-5. The isomerisation reaction proceeded effectively over zeolites ZSM-5 of Si/Al equal of 12 and 32. Among them, the Al-poorer zeolite (Si/Al = 32) was found to offer the highest conversion and selectivity to p-xylene with the lowest number of disproportionation products, both in ortho- and meta-xylene transformation. Further reduction of Brønsted acidity facilitated the disproportionation path (zeolites of Si/Al = 48 and 750). The formation of intermediate species induced by the diffusion constraints for m-xylene in 10-ring channels was rationalized in the terms of the methylbenzenium ions formation inside the rigid micropore environment. Finally, both microporous character of zeolite and the optimised acidity were found to be crucial for high selectivity to the most desired product i.e. p-xylene. The analysis of asynchronous maps allowed for concluding on the order of the appearance of the respective products on the zeolite surface.

Benzene induced resistance in exposed Drosophila melanogaster: Outcome of improved detoxification and gene modulation.

PubMed

Sharma, Divya; Singh, Mahendra Pratap; Vimal, Divya; Kumar, Saurabh; Jha, Rakesh Roshan; Chowdhuri, D Kar

2018-06-01

Adaptive behaviour of an organism has relevance towards developing better resistance in subsequent generations following xenobiotic exposures. Using a genetically tractable and functional insect model, Drosophila melanogaster, we aimed to examine the resistance of the organism against repeated exposures of benzene, an industrial and environmental-chemical and a class I human carcinogen. While 100 mM benzene exposure to one-day old flies for seven days caused ∼95% mortality (F0), its exposure to subsequent generations of flies led a significant decrease in mortality with maximum survival (∼85%) as evident at F28 generation. While burden of benzene and its toxic metabolites was higher in initial generations, in latter generations (F24-F28), concentrations of less toxic metabolites were higher. In parallel, improved metabolism, less oxidative stress, less induction of hsp60 and hsp70 and higher induction of hsp26 and hsp27 along with increased gene dose ratio of three genes (cyp6g1, mrp1, and cyp12d1) were observed in latter generations of benzene exposed flies with maximum benefit accrued in F28 generation. The resistance developed in flies of F28 generation had a negative impact on reproduction which might be due to a cost against selection. The study demonstrates development of benzene resistance in Drosophila with permanent genetic changes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Control of workers’ exposure to xylene in a pesticide production factory

PubMed Central

Mohammadyan, M; Baharfar, Y

2015-01-01

Background: Acute and chronic exposure to xylene can result in a range of negative health effects. However, xylene is widely used and emitted in the air of workplaces. Objectives: To evaluate xylene vapor concentrations to guide the design and evaluation of a local exhaust ventilation (LEV) system to reduce exposure in a pesticide production factory. Method: A real time volatile organic compound (VOC) monitor was used to determine the workers’ time-weighted average (TWA) exposure. A LEV system was designed, and then, workers’ exposure to xylene vapor was evaluated. Results: We found that worker’s exposure to xylene (4.7±5.5 ppm) was lower than the standards recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) and the Occupational safety and health administration (OSHA). Despite the low TWA exposures, the short-term exposures for some workers were higher than STEL levels. Three canopy hoods were designed and installed with capture velocities of 0.508 m second−1 and duct velocity of 10.16 m second−1. Conclusion: We found that an exhaust ventilation system had a significantly reduced occupational exposure to xylene vapor. PMID:25487643

Sustainable hydrogen production from bio-oil model compounds (meta-xylene) and mixtures (1-butanol, meta-xylene and furfural).

PubMed

Bizkarra, K; Barrio, V L; Arias, P L; Cambra, J F

2016-09-01

In the present work m-xylene and an equimolecular mixture of m-xylene, 1-butanol and furfural, all of them bio-oil model compounds, were studied in steam reforming (SR) conditions. Three different nickel catalysts, which showed to be active in 1-butanol SR (Ni/Al2O3, Ni/CeO2-Al2O3 and Ni/La2O3-Al2O3), were tested and compared with thermodynamic equilibrium values. Tests were carried out at temperatures from 800 to 600°C at atmospheric pressure with a steam to carbon ratio (S/C) of 5.0. Despite the different bio-oils fed, the amount of moles going through the catalytic bed was kept constant in order to obtain comparable results. After their use, catalysts were characterized by different techniques and those values were correlated with the activity results. All catalysts were deactivated during the SR of the mixture, mainly by coking. The highest hydrogen yields were obtained with Ni/Al2O3 and Ni/CeO2-Al2O3 catalysts in the SR of m-xylene and SR of the mixture, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of neuropsychological symptoms and exposure to benzene, toluene and xylene among two different furniture worker groups in Izmir.

PubMed

Mandiracioglu, Aliye; Akgur, Serap; Kocabiyik, Nesrin; Sener, Ufuk

2011-10-01

This study was conducted to determine whether there was any exposure to toluene, xylene and benzene and to assess the health impact of these solvents on workers in furniture enterprises in Karabaglar, Izmir. This cross-sectional study covered furniture enterprises in Karabaglar, Izmir. This study was comprised of an exposed group consisting of workers engaged in painting and varnishing and therefore exposed either directly or indirectly toluene, xylene and benzene in the workplace and the non-exposed group engaged in other aspects of production. While a total of 261 individuals completed questionnaires, 210 workers agreed to provide blood samples. Blood solvents levels were determined using gas chromatograph at Ege University, Intoxication Research and Application Centre. The modified EUROQUEST questionnaire was used to assess neuropsychological symptoms and neurological and general examination were performed. Occupational and exposure history, demographic and work-related information was collected. In this study of workers, blood toluene and benzene levels were found to be significantly higher among those engaged in painting and varnishing compared to those who perform other tasks. The average blood toluene and benzene concentrations among exposed workers were 6.95 times and 1.64 times respectively higher than those in the nonexposed groups. Smokers and participants who worked in excess of 8 hours/day had higher blood toluene and benzene levels. The most frequently work-related health complaints were back pain, allergies and asthma. No differences were found in the average scores in the neuropsychological symptoms questionnaire between exposed and non-exposed groups. Neurological examination of two individuals with these complaints revealed a loss of reflexes. The workers were unaware that they were being exposed to solvents at work. Tobacco smoke is a major source of internal exposure to benzene. Improving working conditions in furniture work places is a priority.

Using wintergreen oil for mounting mosquito larvae: a safer alternative to xylene.

PubMed

Koay, J B; Natasya, N N; Nashithatul, Mag; Ihsanuddin, R; Salleh, F M; Azil, A H

2016-01-01

Permanent mounting of fourth instar mosquito larvae is essential for identifying Aedes spp. This procedure requires extensive exposure to xylene, a clearing agent in the mounting process. We investigated wintergreen oil as a substitute for xylene. Five hundred larvae were mounted on slides to evaluate shrinkage or expansion of specimens after clearing using xylene or wintergreen oil. We examined the ventral brush and siphonal hair tufts for species identification and for preservation of morphological characteristics after clearing specimens in xylene or wintergreen oil. Shrinkage of the length of whole larvae and width of the head, thorax and abdomen after mounting was significantly greater after clearing with xylene than with wintergreen oil. The length of the comb scale nearest the ventral brush was similar for both clearing agents. The clarity of the specimens after mounting was improved by clearing with wintergreen oil, but the integrity of the ventral brush and siphonal hair tufts were similar for both clearing agents.

Impact of Propene on Secondary Organic Aerosol Formation from m-Xylene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Chen; Na, Kwangsam; Warren, Bethany

2007-10-15

Propene is widely used in smog chamber experiments to increase the hydroxyl radical (OH) level based on the assumption that the formation of secondary organic aerosol (SOA) from parent hydrocarbon is unaffected. A series ofm-xylene/NOx photooxidation experiments were conducted in the presence of propene in the University of California CECERT atmospheric chamber facility. The experimental data are compared with previousm-xylene/NOx photooxidation work performed in the same chamber facility in the absence of propene (Song et al. Environ. Sci. Technol. 2005, 39, 3143-3149). The result shows that, for similar initial conditions, experiments with propene have lower reaction rates of m-xylene thanmore » those without propene, which indicates that propene reduces OH in the system. Furthermore, experiments with propene showed more than 15% reduction in SOA yield compared to experiments in the absence of propene. Additional experiments ofm-xylene/NOx with CO showed similar trends of suppressing OH and SOA formation. These results indicate that SOA from m-xylene/NOx photooxidation is strongly dependent on the OH level present, which provides evidence for the critical role of OH in SOA formation from aromatic hydrocarbons.« less

Synergistic effect of acidity and extraframework position in faujasite on renewable p-xylene production

PubMed Central

2018-01-01

p-Xylene is a commodity chemical used for the manufacture of plastic bottles and textiles. For the biomass-based route from 2,5-dimethylfuran (DMF) and ethylene, the properties of the catalyst such as acidity effect, product selectivity and catalyst activity play an important role. To determine the effect of acidity and extraframework position in faujasite zeolite on p-xylene selectivity, type Y (Si/Al = 40 and Si/Al = 2.55) and X (Si/Al = 1.25) zeolites containing the extraframework Lewis acids Na+, K+, Li+, Ag+ and Cu+, and a Brønsted acid-containing zeolite, HY (Si/Al = 40), were prepared and tested for p-xylene production under solvent-free conditions and at low conversions (less than 35%). Here it is reported that NaX zeolite catalyses DMF and ethylene conversion to p-xylene with 91% selectivity at 30% conversion, which is better than the 25% p-xylene selectivity obtained when using HY at similar conversion. ANOVA was used to show that there is a synergistic effect between acidity and extraframework position on the rate of p-xylene production. At 7% DMF conversion, Lewis acids were more selective than the Brønsted acid tested (50 versus 30% p-xylene selectivity). p-Xylene selectivity is optimal when using Lewis acids with moderate acidity and extraframework positions located in the faujasite supercage (sites II and III). PMID:29892435

Simultaneous quantitative determination of benzene, toluene, and xylenes in water using mid-infrared evanescent field spectroscopy.

PubMed

Karlowatz, M; Kraft, M; Mizaikoff, B

2004-05-01

Attenuated total reflection mid-infrared spectroscopy is applied for simultaneous detection and quantification of the environmentally relevant analytes benzene, toluene, and the three xylene isomers. The analytes are enriched into a thin polymer membrane coated onto the surface of an internal reflection waveguide, which is exposed to the aqueous sample. Direct detection of analytes permeating into the polymer coating is performed by utilizing evanescent field spectroscopy in the fingerprint range (>10 microm) of the mid-infrared (MIR) spectrum (3-20 microm) without additional sample preparation. All investigated compounds are characterized by well-separated absorption features in the evaluated wavelength regime. Hence, data evaluation was performed by integration of the respective absorption peaks. Limits of detection lower than 20 ppb (v/v) for all xylene isomers, 45 ppb (v/v) for benzene, and 80 ppb (v/v) for toluene have been achieved. The straightforward experimental setup and the achieved detection limits for these environmentally relevant volatile organic compounds in the low-ppb concentration range reveal a substantial potential of MIR evanescent field sensing devices for on-line in situ environmental analysis.

Effects of m-xylene on human equilibrium measured with a quantitative method.

PubMed

Savolainen, K; Linnavuo, M

1979-04-01

Swaying during normal upright posture in 17 young males and the effects of m-xylene exposure on the body sway of six of the 17 has been studied by a quantitative Romberg test, conducted with an equipment consisting of a strain gauge transducer platform and of an electronic unit. The exposures were conducted in a dynamic exposure chamber. The sway of the 17 subjects was larger when their eyes were closed than when they were open (P less than 0.001) indicating the importance of vision in the control of body balance. Exposure to a time-weighted average (TWA) concentration of 100 p.p.m. (4.1 mumol/l) of xylene with 200 p.p.m. (8.2 mumol/l) peaks had no observable effect on the body balance of the six subjects. Exposure to a TWA concentration of 200 p.p.m. of xylene with 400 p.p.m. (16.4 mumol/l) peaks--the corresponding mean concentration of xylene in venous blood being 29.1 +/- 3.2 mumol/l--clearly impaired the body balance of the six subjects. The impairment was most pronounced with the eyes closed (P = 0.016). The results suggest that human equilibrium is rather sensitive to effects of exposure to xylene.

Kerosene: Contributing agent to xylene as a clearing agent in tissue processing.

PubMed

Shah, Amisha Ashokkumar; Kulkarni, Dinraj; Ingale, Yashwant; Koshy, Ajit V; Bhagalia, Sanjay; Bomble, Nikhil

2017-01-01

Research methodology in oral and maxillofacial pathology has illimitable potential. The tissue processing involves many steps of which one of the most important step is "Clearing," which is a process of replacing dehydrant with a substance which is miscible with embedding medium or paraffin wax. Xylene is one of the common clearing agents used in laboratory, but it is also hazardous. The main aim of this study is to substitute conventionally used xylene by a mixture of kerosene and xylene in clearing steps without altering the morphology and staining characteristics of tissue sections. This will also minimize the toxic effects and tend to be more economical. One hundred and twenty bits of tissue samples were collected, each randomly separated into 4 groups (A, B, C and D) and kept for routine tissue processing till the step of clearing; during the step of clearing instead of conventional xylene, we used mixture of xylene and kerosene in 4 ratios ([A-K:X - 50:50]; [B-K:X - 70:30]; [C - Ab. Kerosene]; [D - Ab. Xylene - as control]) and observed for the light microscopic study adopting H and E staining, IHC (D2-40), Special stains (periodic acid-Schiff and congo red) procedure. The result was subjected to statistical analysis by using Fisher's exact test. The results obtained from the present study were compared with control group, i.e., D and it was observed that Groups A and B were absolutely cleared without altering the morphology of tissue and cellular details; optimum embedding characteristics and better staining characteristics were also noted, whereas Group C presents poor staining characteristics with reduced cellular details. Embedded tissues in Group C presented with rough, irregular surface and also appeared shrunken. Combined mixture of xylene and kerosene as a clearing agent in different ratio, i.e., Group A (K:X - 50:50) and B (K:X - 70:30) can be used without posing any health risk or compromising the cellular integrity.

The rate of percutaneous permeation of xylene, measured using the "perfused pig ear" model, is dependent on the effective protein concentration in the perfusing medium.

PubMed

de Lange, J; van Eck, P; Bruijnzeel, P L; Elliott, G R

1994-08-01

In order to study the dermal permeation of compounds through the skin, an in vitro model was developed which utilized pig ears perfused with autologous pig blood (de Lange, J., van Eck, P., Elliott, G. R., de Kort, W. L. A. M., and Wolthuis, O. L. (1992). J. Pharmacol. Toxicol. Methods 27, 71-77). In the present article we investigated to what extent the rate of permeation of xylene through pig ear skin is dependent on the perfusion medium used. Pig ears were exposed to xylene (10 cm2 area) for a 4-hr period (30 degrees C, relative humidity of 40-60%) and the perfusate was analyzed for xylene using gas chromatography. The rates of permeation of xylene for whole blood, blood depleted of white blood cells, and a buffer containing 4.5% albumin were similar (+/- 300 ng/min/cm2). The rate of penetration was fivefold higher when pig plasma was used and ninefold lower when albumin was excluded from the buffer. Using the buffer, we found that the rate of permeation of xylene was proportional to flow (constant protein concentration) and protein concentration (constant flow). Our data demonstrate that the measured permeation rate for xylene is, to a large degree, dependent on the effective protein concentration (mg/min) passing through the ear. Differences in this parameter could explain the variations in rates of permeation found using the different perfusion media. To avoid problems associated with the choice of receptor fluid for permeation experiments, we suggest that full blood remains the vehicle of choice, although the practical perfusion period is limited to about 6 hr. If longer perfusion periods are required, then it should be possible to reproduce results obtained with whole blood by choosing an appropriate buffer.

Near-Ideal Xylene Selectivity in Adaptive Molecular Pillar[ n]arene Crystals.

PubMed

Jie, Kecheng; Liu, Ming; Zhou, Yujuan; Little, Marc A; Pulido, Angeles; Chong, Samantha Y; Stephenson, Andrew; Hughes, Ashlea R; Sakakibara, Fumiyasu; Ogoshi, Tomoki; Blanc, Frédéric; Day, Graeme M; Huang, Feihe; Cooper, Andrew I

2018-06-06

The energy-efficient separation of alkylaromatic compounds is a major industrial sustainability challenge. The use of selectively porous extended frameworks, such as zeolites or metal-organic frameworks, is one solution to this problem. Here, we studied a flexible molecular material, perethylated pillar[ n]arene crystals ( n = 5, 6), which can be used to separate C8 alkylaromatic compounds. Pillar[6]arene is shown to separate para-xylene from its structural isomers, meta-xylene and ortho-xylene, with 90% specificity in the solid state. Selectivity is an intrinsic property of the pillar[6]arene host, with the flexible pillar[6]arene cavities adapting during adsorption thus enabling preferential adsorption of para-xylene in the solid state. The flexibility of pillar[6]arene as a solid sorbent is rationalized using molecular conformer searches and crystal structure prediction (CSP) combined with comprehensive characterization by X-ray diffraction and 13 C solid-state NMR spectroscopy. The CSP study, which takes into account the structural variability of pillar[6]arene, breaks new ground in its own right and showcases the feasibility of applying CSP methods to understand and ultimately to predict the behavior of soft, adaptive molecular crystals.

Biodiesel production from wet municipal sludge: evaluation of in situ transesterification using xylene as a cosolvent.

PubMed

Choi, O K; Song, J S; Cha, D K; Lee, J W

2014-08-01

This study proposes a method to produce biodiesel from wet wastewater sludge. Xylene was used as an alternative cosolvent to hexane for transesterification in order to enhance the biodiesel yield from wet wastewater sludge. The water present in the sludge could be separated during transesterification by employing xylene, which has a higher boiling point than water. Xylene enhanced the biodiesel yield up to 8.12%, which was 2.5 times higher than hexane. It was comparable to the maximum biodiesel yield of 9.68% obtained from dried sludge. Xylene could reduce either the reaction time or methanol consumption, when compared to hexane for a similar yield. The fatty acid methyl esters (FAMEs) content of the biodiesel increased approximately two fold by changing the cosolvent from hexane to xylene. The transesterification method using xylene as a cosolvent can be applied effectively and economically for biodiesel recovery from wet wastewater sludge without drying process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exposure to benzene, toluene, xylenes and total hydrocarbons among snowmobile drivers in Sweden.

PubMed

Eriksson, Kåre; Tjärner, Dan; Marqvardsen, Inger; Järvholm, Bengt

2003-03-01

The exposure to benzene, toluene, xylenes and total hydrocarbons among 25 individuals exposed to exhaust from a snowmobile equipped with a two-stroke engine has been evaluated. Sampling was performed by pumped and diffusive sampling in parallel. There was a relatively bad agreement between the two air-sampling methods. The bad agreement can in part be explained by back diffusion of the substances from the samplers, a high face velocity, and deposition of droplets of unburned gasoline onto or in the vicinity of the samplers. The levels of benzene ranged from not detectable (< or =0.01 mgm(-3)) to 2.5 mgm(-3). For toluene, xylenes and total hydrocarbons the exposure was 0.10-12.0, < or =0.05-13.0 and 0.90-273 mgm(-3) respectively. The result from two measurements on individuals travelling on an open sleigh at the rear of the vehicle indicated higher levels of benzene, 0.7-0.8 mgm(-3). Children are often riding as a passenger on a sledge and may thus have a higher exposure than their parents. This study indicates that spare time driving a snowmobile may cause a considerable exposure to benzene. Using a four-stroke engine equipped with a catalyst could reduce the exposure. To reduce the exposure for the passenger on a sleigh an extension of the exhaust pipe may be effective.

Metabolomic Analysis Provides Insights on Paraquat-Induced Parkinson-Like Symptoms in Drosophila melanogaster.

PubMed

Shukla, Arvind Kumar; Ratnasekhar, Ch; Pragya, Prakash; Chaouhan, Hitesh Singh; Patel, Devendra Kumar; Chowdhuri, Debapratim Kar; Mudiam, Mohana Krishna Reddy

2016-01-01

Paraquat (PQ) exposure causes degeneration of the dopaminergic neurons in an exposed organism while altered metabolism has a role in various neurodegenerative disorders. Therefore, the study presented here was conceived to depict the role of altered metabolism in PQ-induced Parkinson-like symptoms and to explore Drosophila as a potential model organism for such studies. Metabolic profile was generated in control and in flies that were fed PQ (5, 10, and 20 mM) in the diet for 12 and 24 h concurrent with assessment of indices of oxidative stress, dopaminergic neurodegeneration, and behavioral alteration. PQ was found to significantly alter 24 metabolites belonging to different biological pathways along with significant alterations in the above indices. In addition, PQ attenuated brain dopamine content in the exposed organism. The study demonstrates that PQ-induced alteration in the metabolites leads to oxidative stress and neurodegeneration in the exposed organism along with movement disorder, a phenotype typical of Parkinson-like symptoms. The study is relevant in the context of Drosophila and humans because similar alteration in the metabolic pathways has been observed in both PQ-exposed Drosophila and in postmortem samples of patients with Parkinsonism. Furthermore, this study provides advocacy towards the applicability of Drosophila as an alternate model organism for pre-screening of environmental chemicals for their neurodegenerative potential with altered metabolism.

Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

NASA Astrophysics Data System (ADS)

Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; Di Fulvio, A.; Clarke, S. D.; Pozzi, S. A.; Febbraro, M.

2016-06-01

In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. ×3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and EJ315) this scintillator can provide good pulse-shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene-based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition EJ301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light-response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective (×10 to ×100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. As we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse-selected beam (as needed for time-of-flight) is not available.

SOA formation from photooxidation of naphthalene and methylnaphthalenes with m-xylene and surrogate mixtures

NASA Astrophysics Data System (ADS)

Chen, Chia-Li; Li, Lijie; Tang, Ping; Cocker, David R.

2018-05-01

SOA formation is not well predicted in current models in urban area. The interaction among multiple anthropogenic volatile organic compounds is essential for the SOA formation in the complex urban atmosphere. Secondary organic aerosol (SOA) from the photooxidation of naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene as well as individual polycyclic aromatic hydrocarbons (PAHs) mixed with m-xylene or an atmospheric surrogate mixture was explored in the UCR CE-CERT environmental chamber under urban relevant low NOx and extremely low NOx (H2O2) conditions. Addition of m-xylene suppressed SOA formation from the individual PAH precursor. A similar suppression effect on SOA formation was observed during the surrogate mixture photooxidation suggesting the importance of gas-phase chemical reactivity to SOA formation. The SOA growth rate for different PAH-m-xylene mixtures was strongly correlated with initial [HO2]/[RO2] ratio but negatively correlated with initial m-xylene/NO ratio. Decreasing SOA formation was observed for increasing m-xylene/PAHs ratios and increasing initial m-xylene/NO ratio. The SOA chemical composition characteristics such as f44 versus f43, H/C ratio, O/C ratio, and the oxidation state of the carbon OSbarc were consistent with a continuously aging with the SOA exhibiting characteristics of both individual precursors. SOA formation from PAHs was also suppressed within an atmospheric surrogate mixture compared to the SOA formed from individual PAHs, indicating that atmospheric reactivity directly influences SOA formation from PAHs.

Enhanced xylene removal by photocatalytic oxidation using fiber-illuminated honeycomb reactor at ppb level.

PubMed

Wu, Yi-Ting; Yu, Yi-Hui; Nguyen, Van-Huy; Lu, Kung-Te; Wu, Jeffrey Chi-Sheng; Chang, Luh-Maan; Kuo, Chi-Wen

2013-11-15

The removal of volatile organic compounds (VOCs) at ppb level is one of the most critical challenges in clean rooms for the semiconductor industry. Photocatalytic oxidation is an innovative and promising technology for ppb-level VOCs degradation. We have designed a fiber-illuminated honeycomb reactor (FIHR) in which the removal efficiency of m-xylene is significantly enhanced to 96.5% as compared to 22.0% for UV irradiation only. The results indicate that photocatalysts not only play the role to substantially oxidize m-xylene, but also alter the chemical properties of xylene under UV illumination. Using the FIHR with Mn-TiO2 photocatalyst not only increased the m-xylene removal efficiency, but also increased the CO2 selectivity. Interestingly, Mn-TiO2 in FIHR also showed a very good reusability, 93% removal efficiency was still achieved in 72-h in reaction. Thus, the FIHR gave very high removal efficiency for xylene at ppb level under room temperature. The FIHR has great potential application in the clean room for the air purification system in the future. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparative efficacy of cedarwood oil and xylene in hematoxylin and eosin staining procedures: An experimental study.

PubMed

Indu, Sudip; Ramesh, V; Indu, Priyanka Chakravarty; Prashad, Karthikshree V; Premalatha, B; Ramadoss, K

2014-07-01

Xylene is used as a clearing agent in hematoxylin and eosin (H and E) staining of tissue sections in routine histopathology based diagnosis. However, the hazards associated with exposure to xylene are of concern. Numerous solutions mainly essential oils have been evaluated in the past as clearing agents, which can possibly be substituted for xylene during the routine tissue processing. The aim of this study is to compare the efficacy of essential oil (cedarwood oil), as a possible replacement for xylene in H and E staining procedures. The study was carried out in the Department of Oral Pathology and Microbiology. Thirty paraffin blocks of the routine biopsy specimen were retrieved from the department archives. The cedarwood oil was procured from organic and essential oil dealer in the local market. Two to three paraffin sections of four micron thickness were cut from each of the 30 paraffin blocks of processed tissue specimens, were subjected to different clearing agents: Essential oil (8% cedarwood oil) or xylene and stained with H and E stain. The stained sections were scored based on nuclear and cytoplasmic details, clarity and uniformity of staining. Significant correlation was observed between cedarwood oil and xylene in terms of the three staining quality parameters assessed. We conclude that cedarwood oil can be an effective, eco-friendly and safe alternative to xylene as a clearing agent in the histopathological laboratory.

Ultrastructural findings in the brain of fruit flies (Drosophila melanogaster) and mice exposed to high-energy particle radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

D'Amelio, F.; Kraft, L.M.; D'Antoni-D'Amelio, E.

1984-01-01

Effects of high energy, heavy particle (HZE) radiation were studied in the brain of the fruit fly (Drosophila melanogaster) exposed to argon (40Ar) or krypton (84Kr) ions. In the flies exposed to argon the fluence ranged from 6 X 10(4) to 8 X 10(7) particles/cm2. The insects were killed 35 days after exposure. Extensive tissue fragmentation was observed at the higher fluence employed. At fluences ranging from 5 X 10(6) (one hit/two cell bodies) to 9 X 10(4) (one hit/90 cell bodies) particles/cm2, swelling of the neuronal cytoplasm and focally fragmented membranes was observed. Marked increase of glial lamellae aroundmore » nerve cell processes was seen at fluences ranging from one hit/six to one hit/135 cell bodies. In the flies irradiated with krypton, the fluences employed were 5.8 X 10(3) and 2.2 X 10(6) particles/cm2. Acute and late effects were evaluated. In the flies killed 36 hours after exposure (acute effects) to either fluence, glycogen particles were found in the neuroglial compartment. The granules were no longer present in flies killed 35 days later (late effects). From these studies it appears that the Drosophila brain is a useful model to investigate radiation damage to mature neurons, neuroglia, and therefore, to the glio-neuronal metabolic unit. In a separate study, the synaptic profiles of the neuropil in layers II-III of the frontal cerebral cortex of anesthesized adult LAFl mice were quantitatively appraised after exposure to argon (40Ar) particles. The absorbed dose ranged from 0.05 to 5 gray (Gy) plateau. It was determined that the sodium pentobarbital anesthesia per se results in a significant decrease in synaptic profile length one day after anesthetization, with return to normal values after 2-28 days. Irradiation with 0.05-5 Gy argon particles significantly inhibited the synaptic shortening effect of anesthesia at one day after exposure.« less

Organochlorine pesticide, endosulfan induced cellular and organismal response in Drosophila melanogaster.

PubMed

Sharma, Anurag; Mishra, M; Shukla, A K; Kumar, R; Abdin, M Z; Chowdhuri, D Kar

2012-06-30

The effect of endosulfan (0.02-2.0μgmL(-1)) to Drosophila melanogaster (Oregon R(+)) at the cellular and organismal levels was examined. Third instar larvae of D. melanogaster and the strains transgenic for hsp70, hsp83 and hsp26 were exposed to endosulfan through food for 12-48h to examine the heat shock proteins (hsps), reactive oxygen species (ROS) generation, anti-oxidant stress markers and xenobiotic metabolism enzymes. We observed a concentration- and time-dependent significant induction of only small hsps (hsp23>hsp22) in the exposed organism in concurrence with a significant induction of ROS generation, oxidative stress and xenobiotic metabolism markers. Sub-organismal response was to be propagated towards organismal response, i.e., delay in the emergence of flies and decreased locomotor behaviour. Organisms with diminished locomotion also exhibited significantly lowered acetylcholinesterase activity. A significant positive correlation observed among ROS generation and different cellular endpoints (small hsps, oxidative stress markers, cytochrome P450 activities) in the exposed organism indicate a modulatory role of ROS in endosulfan-mediated cellular toxicity. The study thus suggests that the adverse effects of endosulfan in exposed Drosophila are manifested both at cellular and organismal levels and recommends Drosophila as an alternative animal model for screening the risk caused by environmental chemicals. Copyright © 2012 Elsevier B.V. All rights reserved.

Local viscosity and solvent relaxation experienced by rod-like fluorophores in AOT/4-chlorophenol/m-xylene organogels

NASA Astrophysics Data System (ADS)

Dandapat, Manika; Mandal, Debabrata

2017-01-01

Organogels prepared from AOT/4-chlorophenol/m-xylene are immobile in the macroscopic sense, with a well-characterized internal structure. However, the molecular level dynamics inside the gels is not too clear, although a very slow structural relaxation has been reported previously. Using a set of rod-like fluorophores, we find that the rotational mobility of a small guest molecule inside the gel can be extremely fast, indicating presence of sufficiently low-microviscosity domains. These domains consist of m-xylene solvent molecules trapped in the interstices of fiber bundles comprising columnar stacks of 4-chlorophenol surrounded by AOT molecules. However, interstitial trapping of m-xylene does retard its own dynamics, which explains the slow solvent relaxation inside the gels. Hence, the state of m-xylene in the organogel may be characterized as "bound", in contrast to the "free" state in neat m-xylene.

Tacrolimus hydrate ointment inhibits skin plasma extravasation in rats induced by topical m-xylene but not capsaicin.

PubMed

Goto, Shiho; Kondo, Fumio; Ikai, Yoshitomo; Miyake, Mio; Futamura, Masaki; Ito, Komei; Sakamoto, Tatsuo

2009-04-17

Tacrolimus ointment is used to treat various chronic inflammatory skin diseases. However, the effect of this ointment on acute neurogenic inflammation in the skin remains to be fully elucidated. Topical capsaicin and m-xylene produce tachykinin release from sensory nerves in the skin, resulting in skin plasma leakage. We investigated the effect of tacrolimus ointment (0.1%) on skin microvascular leakage induced by topical capsaicin (10 mM) and m-xylene (neat), and intracutaneous compound 48/80 (c48/80) (10 microg/ml, 50 microl/site) in two groups of rats pretreated with excessive capsaicin or its vehicle. The amount of leaked Evans blue dye reflected skin plasma leakage. Capsaicin, m-xylene or c48/80 was applied to the shaved abdomens of rats 8 h after topical application of tacrolimus ointment or its base. Desensitization with capsaicin reduced the skin response to capsaicin and m-xylene by 100% and 65%, respectively, but not to c48/80. Tacrolimus ointment significantly inhibited the skin response induced by m-xylene and c48/80, regardless of pretreatment with capsaicin. However, topical tacrolimus did not influence the skin response induced by capsaicin. We also evaluated whether topical capsaicin and m-xylene, and intracutaneous c48/80 cause mast cell degranulation in skin treated with tacrolimus. Mast cell degranulation was microscopically assessed. Topical tacrolimus only significantly suppressed degranulation induced by m-xylene and c48/80. Our data shows that tacrolimus ointment partially inhibits plasma leakage and mast cell degranulation in rat skin induced by m-xylene and c48/80 but not capsaicin, suggesting that the inhibitory effect is not associated with a reduction in neurogenic-mediated mechanisms.

Urine Methyl Hippuric Acid Levels in Acute Pesticide Poisoning: Estimation of Ingested Xylene Volume and Association with Clinical Outcome Parameters.

PubMed

Choi, Chi Young; Cho, NamJun; Park, Su Yeon; Park, Samel; Gil, Hyo Wook; Hong, Sae Yong

2017-12-01

To determine the relationship between the oral ingestion volume of xylene and methyl hippuric acid (MHA) in urine, we measured MHA in 11 patients whose ingested xylene volume was identified. The best-fit equation between urine MHA and ingested amount of xylene was as follows: y (ingested amount of xylene, mL/kg) = -0.052x² + 0.756x (x = MHA in urine in g/g creatinine). From this equation, we estimated the ingested xylene volume in 194 patients who had ingested pesticide of which the formulation was not available. Our results demonstrated that oxadiazole, dinitroaniline, chloroacetamide, organophosphate, and pyrethroid were xylene-containing pesticide classes, while the paraquat, glyphosate, glufosinate, synthetic auxin, fungicide, neonicotinoid, and carbamate classes were xylene-free pesticides. Sub-group univariate analysis showed a significant association between MHA levels in urine and ventilator necessity in the pyrethroid group. However, this association was not observed in the organophosphate group. Our results suggest that MHA in urine is a surrogate marker for xylene ingestion, and high urine MHA levels may be a risk factor for poor clinical outcome with some pesticide poisoning. © 2017 The Korean Academy of Medical Sciences.

Effects of space flight factors on Drosophila.

PubMed

Dubinin, N P; Glembotsky, Y L; Vaulina, E N; Grozdova, T Y; Kamshilova, E M; Ivaschenko, N I; Kholikova, I A; Nechitailo, G S; Mashinsky, A L; Iordanishvili, E K

1973-01-01

Drosophila melanogaster flies of strain D-32 were exposed aboard the Soyuz 10 spaceship. An insert with a nutritional medium and insects was placed in a small on-board thermostat (Biotherm II) providing a constant temperature (24 degrees C +/- 1 degree) for Drosophila development. The frequency of dominant lethals was determined in the females. Dominant, autosomal and sex-linked recessive lethals were estimated in hatching virgin males and females; the time of hatching was rigorously fixed. Sex-linked recessive lethals were related to certain stages of gametogenesis. The 1-5 oocyte stage showed an increased sensitivity to space-flight factors as regards the frequency of both dominant and recessive lethals.

Substrate Interactions during the Biodegradation of Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) Hydrocarbons by the Fungus Cladophialophora sp. Strain T1

PubMed Central

Prenafeta-Boldú, F. X.; Vervoort, J.; Grotenhuis, J. T. C.; van Groenestijn, J. W.

2002-01-01

The soil fungus Cladophialophora sp. strain T1 (= ATCC MYA-2335) was capable of growth on a model water-soluble fraction of gasoline that contained all six BTEX components (benzene, toluene, ethylbenzene, and the xylene isomers). Benzene was not metabolized, but the alkylated benzenes (toluene, ethylbenzene, and xylenes) were degraded by a combination of assimilation and cometabolism. Toluene and ethylbenzene were used as sources of carbon and energy, whereas the xylenes were cometabolized to different extents. o-Xylene and m-xylene were converted to phthalates as end metabolites; p-xylene was not degraded in complex BTEX mixtures but, in combination with toluene, appeared to be mineralized. The metabolic profiles and the inhibitory nature of the substrate interactions indicated that toluene, ethylbenzene, and xylene were degraded at the side chain by the same monooxygenase enzyme. Our findings suggest that soil fungi could contribute significantly to bioremediation of BTEX pollution. PMID:12039717

VARIATIONS AT A QUANTITATIVE TRAIT LOCUS (QTL) AFFECT DEVELOPMENT OF BEHAVIOR IN LEAD-EXPOSED DROSOPHILA MELANOGASTER

PubMed Central

Hirsch, Helmut V. B.; Possidente, Debra; Averill, Sarah; Despain, Tamira Palmetto; Buytkins, Joel; Thomas, Valerie; Goebel, W. Paul; Shipp-Hilts, Asante; Wilson, Diane; Hollocher, Kurt; Possidente, Bernard; Lnenicka, Greg; Ruden, Douglas M.

2009-01-01

We developed Drosophila melanogaster as a model to study correlated behavioral, neuronal and genetic effects of the neurotoxin lead, known to affect cognitive and behavioral development in children. We showed that, as in vertebrates, lead affects both synaptic development and complex behaviors (courtship, fecundity, locomotor activity) in Drosophila. By assessing differential behavioral responses to developmental lead exposure among recombinant inbred Drosophila lines (RI), derived from parental lines Oregon R and Russian 2b, we have now identified a genotype by environment interaction (GEI) for a behavioral trait affected by lead. Drosophila Activity Monitors (TriKinetics, Waltham, MA), which measure activity by counting the number of times a single fly in a small glass tube walks through an infrared beam aimed at the middle of the tube, were used to measure activity of flies, reared from eggs to 4 days of adult age on either control or lead-contaminated medium, from each of 75 RI lines. We observed a significant statistical association between the effect of lead on average daytime activity across lines and one marker locus, 30AB, on chromosome 2; we define this as a Quantitative Trait Locus (QTL) associated with behavioral effects of developmental lead exposure. When 30AB was from Russian 2b, lead significantly increased locomotor activity, whereas, when 30AB was from Oregon R, lead decreased it. 30AB contains about 125 genes among which are likely “candidate genes” for the observed lead-dependent behavioral changes. Drosophila are thus a useful, underutilized model for studying behavioral, synaptic and genetic changes following chronic exposure to lead or other neurotoxins during development. PMID:19428504

Characterization of the effect of Cr(VI) on humoral innate immunity using Drosophila melanogaster.

PubMed

Pragya, P; Shukla, A K; Murthy, R C; Abdin, M Z; Kar Chowdhuri, D

2015-11-01

With the advancement of human race, different anthropogenic activities have heaped the environment with chemicals that can cause alteration in the immune system of exposed organism. As a first line of barrier, the evolutionary conserved innate immunity is crucial for the health of an organism. However, there is paucity of information regarding in vivo assessment of the effect of environmental chemicals on innate immunity. Therefore, we examined the effect of a widely used environmental chemical, Cr(VI), on humoral innate immune response using Drosophila melanogaster. The adverse effect of Cr(VI) on host humoral response was characterized by decreased gene expression of antimicrobial peptides (AMPs) in the exposed organism. Concurrently, a significantly decreased transcription of humoral pathway receptors (Toll and PGRP) and triglyceride level along with inhibition of antioxidant enzyme activities were observed in exposed organism. This in turn weakened the immune response of exposed organism that was manifested by their reduced resistance against bacterial infection. In addition, overexpression of the components of humoral immunity particularly Diptericin benefits Drosophila from Cr(VI)-induced humoral immune-suppressive effect. To our knowledge, this is the first report regarding negative impact of an environmental chemical on humoral innate immune response of Drosophila along with subsequent protection by AMPs, which may provide novel insight into host-chemical interactions. Also, our data validate the utility and sensitivity of Drosophila as a model that could be used for screening the possible risk of environmental chemicals on innate immunity with minimum ethical concern that can be further extrapolated to higher organisms. © 2014 Wiley Periodicals, Inc.

Methods for the synthesis and polymerization of .alpha.,.alpha.'-dihalo-p-xylenes

DOEpatents

Ferraris, John P.; Neef, Charles J.

2002-07-30

The present invention describes an improved method for the polymerization of .alpha.,.alpha.-dihalo-p-xylene's such as the .alpha.,.alpha.'-dihalo-2-methoxy-5-(2-ethylhexyloxy)-xylene's. The procedure for synthesis is based on the specific order of addition of reagents and the use of an anionic initiator that allows control of the molecular weight of the polymer. The molecular weight control allows processability of the polymer which is important for its utility in applications including in light-emitting-diodes, field effect transistors and photovoltaic devices.

Mixture effects of benzene, toluene, ethylbenzene, and xylenes (BTEX) on lung carcinoma cells via a hanging drop air exposure system.

PubMed

Liu, Faye F; Escher, Beate I; Were, Stephen; Duffy, Lesley; Ng, Jack C

2014-06-16

A recently developed hanging drop air exposure system for toxicity studies of volatile chemicals was applied to evaluate the cell viability of lung carcinoma A549 cells after 1 and 24 h of exposure to benzene, toluene, ethylbenzene, and xylenes (BTEX) as individual compounds and as mixtures of four or six components. The cellular chemical concentrations causing 50% reduction of cell viability (EC50) were calculated using a mass balance model and came to 17, 12, 11, 9, 4, and 4 mmol/kg cell dry weight for benzene, toluene, ethylbenzene, m-xylene, o-xylene, and p-xylene, respectively, after 1 h of exposure. The EC50 decreased by a factor of 4 after 24 h of exposure. All mixture effects were best described by the mixture toxicity model of concentration addition, which is valid for chemicals with the same mode of action. Good agreement with the model predictions was found for benzene, toluene, ethylbenzene, and m-xylene at four different representative fixed concentration ratios after 1 h of exposure, but lower agreement with mixture prediction was obtained after 24 h of exposure. A recreated car exhaust mixture, which involved the contribution of the more toxic p-xylene and o-xylene, yielded an acceptable, but lower quality, prediction as well.

The synergetic effect of UV rays on the decomposition of xylene in dielectric barrier discharge plasma and photocatalyst process

NASA Astrophysics Data System (ADS)

Li, Wenjuan; Gu, Zhenyu; Teng, Fuhua; Lu, Jianhai; Dong, Shibi; Miao, Xiaoping; Wu, Zhongbiao

2018-06-01

The degradation of xylene in the dielectric barrier discharge plasma and photocatalyst process was studied, focusing on the synergetic effect of UV rays from plasma process and external UV lamps on the decomposition of xylene. The results showed that xylene could be decomposed by the discharge process in plasma system, whereas the UV rays from plasma process was very weak. After adding TiO2, the removal efficiency of xylene and energy yield in plasma process were enhanced since energetic particles activated the catalysis of TiO2. The removal efficiency of xylene and energy field in plasma and photocatalyst process combined with external UV lamps were further enhanced attributed to the degradation effect of plasma, the catalysis of TiO2 activated by plasma, the photolysis of UV rays and the photocatalysis of photocatalyst. The synergetic effect of UV rays from external UV lamps was obvious.

A comparison of Frost expression among species and life stages of Drosophila.

PubMed

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.

The influence of light on temperature preference in Drosophila

PubMed Central

Head, Lauren M.; Tang, Xin; Hayley, Sean E.; Goda, Tadahiro; Umezaki, Yujiro; Chang, Elaine C.; Leslie, Jennifer R.; Fujiwara, Mana; Garrity, Paul A.; Hamada, Fumika N.

2015-01-01

Ambient light affects multiple physiological functions and behaviors, such as circadian rhythms, sleep-wake activities, and development from flies to mammals [1–6]. Mammals exhibit a higher body temperature when exposed to acute light compared to when they are exposed to dark, but the underlying mechanisms are largely unknown [7–10]. The body temperature of small ecotherms, such as Drosophila, rely on the temperature of their surrounding environment and these animals exhibit a robust temperature preference behavior [11–13]. Here, we demonstrate that Drosophila prefer a one-degree higher temperature when exposed to acute light rather than dark. This acute light response, light dependent temperature preference (LDTP), was observed regardless of the time of day, suggesting that LDTP is regulated separately from the circadian clock. However, screening of eye and circadian clock mutants suggests that the circadian clock neurons, posterior dorsal neurons 1 (DN1ps) and pigment-dispersing factor receptor (pdfr) play a role in LDTP. To further investigate the role of DN1ps in LDTP, pdfr in DN1ps was knocked down, resulting in an abnormal LDTP. The phenotype of the pdfr mutant was sufficiently rescued by expressing pdfr in DN1ps, indicating that pdfr expression in DN1ps is responsible for LDTP. These results suggest that light positively influences temperature preference via the circadian clock neurons, DN1ps, which may result from the integration of light and temperature information. Given that both Drosophila and mammals respond to acute light by increasing their body temperature, the effect of acute light on temperature regulation may be conserved evolutionarily between flies and humans. PMID:25866391

A Green Alternative to Aluminum Chloride Alkylation of Xylene

ERIC Educational Resources Information Center

Sereda, Grigoriy A.; Rajpara, Vikul B.

2007-01-01

An acutely less toxic 2-bromobutane is used to develop a simple graphite-promoted procedure of alkylation of p-xylene. It is further demonstrated that aluminum chloride is not required, the need for aqueous workup is eliminated, waste solutions are not produced and the multiple use of the catalyst is allowed.

Over-Expression of Superoxide Dismutase Ameliorates Cr(VI) Induced Adverse Effects via Modulating Cellular Immune System of Drosophila melanogaster

PubMed Central

Pragya, Prakash; Shukla, Arvind Kumar; Murthy, Ramesh Chandra; Abdin, Malik Zainul; Kar Chowdhuri, Debapratim

2014-01-01

The evolutionarily conserved innate immune system plays critical role for maintaining the health of an organism. However, a number of environmental chemicals including metals are known to exert adverse effects on immune system. The present study assessed the in vivo effect of a major environmental chemical, Cr(VI), on cellular immune response using Drosophila melanogaster and subsequently the protective role of superoxide dismutase (SOD) based on the comparable performance of the tested anti-oxidant enzymes. The immuno-modulatory potential of Cr(VI) was demonstrated by observing a significant reduction in the total hemocyte count along with impaired phagocytic activity in exposed organism. Concurrently, a significant increase in the percentage of Annexin V-FITC positive cells, activation of DEVDase activity, generation of free radical species along with inhibition of anti-oxidant enzyme activities was observed in the hemocytes of exposed organism. In addition, we have shown that ONOO− is primarily responsible for Cr(VI) induced adverse effects on Drosophila hemocytes along with O2 −. While generation of O2 −/ONOO− in Cr(VI) exposed Drosophila hemocytes was found to be responsible for the suppression of Drosophila cellular immune response, Cr(VI) induced alteration was significantly reduced by the over-expression of sod in Drosophila hemocytes. Overall, our results suggest that manipulation of one of the anti-oxidant genes, sod, benefits the organism from Cr(VI) induced alteration in cellular immunity. Further, this study demonstrates the applicability of D. melanogaster to examine the possible effects of environmental chemicals on innate immunity which can be extrapolated to higher organisms due to evolutionary conservation of innate immune system between Drosophila and mammals. PMID:24505420

Innate and intrinsic antiviral immunity in Drosophila.

PubMed

Mussabekova, Assel; Daeffler, Laurent; Imler, Jean-Luc

2017-06-01

The fruit fly Drosophila melanogaster has been a valuable model to investigate the genetic mechanisms of innate immunity. Initially focused on the resistance to bacteria and fungi, these studies have been extended to include antiviral immunity over the last decade. Like all living organisms, insects are continually exposed to viruses and have developed efficient defense mechanisms. We review here our current understanding on antiviral host defense in fruit flies. A major antiviral defense in Drosophila is RNA interference, in particular the small interfering (si) RNA pathway. In addition, complex inducible responses and restriction factors contribute to the control of infections. Some of the genes involved in these pathways have been conserved through evolution, highlighting loci that may account for susceptibility to viral infections in humans. Other genes are not conserved and represent species-specific innovations.

Coexposure to toluene and p-xylene in man: central nervous functions.

PubMed Central

Olson, B A; Gamberale, F; Iregren, A

1985-01-01

Sixteen men were studied in an exposure chamber to assess the effect of four hours' exposure to toluene (3.25 mmol/m3), xylene (2.84 mmol/m3), a mixture of toluene and xylene (2.20 + 0.94 mmol/m3), and a control condition. With the aid of microcomputers, subjects performed tests of simple reaction time, short term memory, and choice reaction time immediately after entering the chamber, after two, and after four hours' exposure. The results indicate that the performance on the tests was unaffected by exposure. In the light of this result the risk of an acute effect on central nervous functions after exposure for four hours at concentrations that do not exceed the Swedish threshold limit values was considered to be minimal. PMID:3970870

Demonstration of In situ Anaerobic Transformation of Toluene and Xylene Using Single-Well Push-Pull Tests and Deuterated BTEX Surrogates

NASA Astrophysics Data System (ADS)

Field, J. A.; Reusser, D. E.; Beller, H. R.; Istok, J. D.

2001-12-01

Obtaining unambiguous evidence of in-situ transformation of benzene, toluene, ethylbenzene and xylene (BTEX) in the subsurface is a difficult task. Recently, benzylsuccinic acid and its methyl analogues were shown to be unequivocal degradation products of anaerobic toluene and xylene biodegradation. Conducting tracer tests at BTEX-contaminated field sites is problematic because background contaminant concentrations potentially interfere with the interpretation of field test data. To avoid the time and cost associated with removing background contaminants, alternative approaches are needed. Deuterated analogs of toluene and xylene are well-suited for use in field tracer tests because they are inexpensive and can be distinguished analytically from background toluene and xylene. In this study, single-well push-pull tests, in which deuterated toluene and xylene were injected, were performed to assess the in-situ anaerobic biotransformation of toluene and xylene in BTEX-contaminated wells. A total of 4 single-well push-pull tests were conducted at BTEX-contaminated field sites near Portland, OR and Kansas City, KS. Test solutions consisting of 100 mg/L bromide, 250 mg/L nitrate, 0.4 to 2.5 mg/L toluene-d8, and 0.4 to 1.0 mg/L o-xylene-d10.were injected at a rate of 0.5 - 2 L/min. During the extraction phase, samples were taken daily to biweekly for up to 30 days. Samples for volatile organic analytes were collected in 40-mL volatile organic analysis (VOA) vials without headspace. Samples for BSA and methyl-BSA were collected in 1 L glass bottles and preserved with 5% (w/w) formalin. Samples were shipped on ice and stored at 4 C until analysis. Unambiguous evidence of toluene and xylene biotransformation was obtained with the in-situ formation of BSA and methyl-BSA. The concentrations of BSA ranged from below the detection limit (0.2 ug/L) to 1.5 ug/L. The concentrations of methyl-BSA ranged from below detection to the quantitation limit (0.7 ug/L). The highest BSA

Transcriptomic Response of Drosophila Melanogaster Pupae Developed in Hypergravity

NASA Technical Reports Server (NTRS)

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 < 0.05) difference in gene expression. Five major biological processes were affected: ion transport, redox homeostasis, immune response, proteolysis, and cuticle development. This outlines the underlying molecular changes occurring in Drosophila pupae in response to hypergravity.

Innate and intrinsic antiviral immunity in Drosophila

PubMed Central

Mussabekova, Assel; Daeffler, Laurent; Imler, Jean-Luc

2017-01-01

The fruitfly Drosophila melanogaster has been a valuable model to investigate the genetic mechanisms of innate immunity. Initially focused on the resistance to bacteria and fungi, these studies have been extended to include antiviral immunity over the last decade. Like all living organisms, insects are continually exposed to viruses and have developed efficient defense mechanisms. We review here our current understanding on antiviral host-defense in fruit flies. A major antiviral defense in Drosophila is RNA interference, in particular the small interfering (si) RNA pathway. In addition, complex inducible responses and restriction factors contribute to the control of infections. Some of the genes involved in these pathways have been conserved through evolution, highlighting loci that may account for susceptibility to viral infections in humans. Other genes are not conserved and represent species-specific innovations. PMID:28102430

The effectiveness of eucalyptus oil, orange oil, and xylene in dissolving different endodontic sealers.

PubMed

Yadav, Hemant Kumar; Yadav, Rakesh Kumar; Chandra, Anil; Thakkar, Rahul Rameshbhai

2016-01-01

The objective of this study was to evaluate the dissolution effectiveness of eucalyptus oil, orange oil, xylene, and distilled water on three different endodontic sealers. About 240 samples of root canal sealers (eighty for each sealer) were prepared and divided into four groups of 20 each for immersion in different organic solvents. Each group was further subdivided into two subgroups (n = 10) for 2 and 10 min of immersion time. The mean percentage of weight loss was determined for each sealer in each solvent at both time periods. Data were statistically analyzed by two factor analysis of variance and significance of mean difference was obtained by Tukey's post hoc test (P < 0.05). The lowest level of solubility was observed for Adseal followed by Apexit Plus and Endomethasone N at both time periods in all solvents. Apexit Plus showed no significant (P > 0.05) difference in its dissolution in all the organic solvents except distilled water at both the time periods. The solubility profile of Endomethasone N and Adseal did not differ significantly among eucalyptus oil, orange oil, and xylene at 2 min and between eucalyptus oil and orange oil at 10 min. However, at 10 min, Endomethasone N and Adseal showed a more pronounced solubility in xylene as compared to both eucalyptus oil and orange oil. In general, xylene was the most effective in dissolving root canal sealers than other organic solvents. Essential oils (eucalyptus oil and orange oil) were found similar in their ability to dissolve Apexit Plus and Endomethasone N.

The effect of space environment on the development and aging of Drosophila Melanogaster (7-IML-1)

NASA Technical Reports Server (NTRS)

Marco, Roberto

1992-01-01

This experiment involves the study of the development of eggs of the fly, Drosophila, exposed to microgravity. It is presumed that oogenesis, rather than further states of embryonic development, is sensitive to gravity. This hypothesis will be tested by collecting eggs layered at specific times inflight and postflight from flies exposed to 0 and 1 g. This portion of the experiment is a repetition of an earlier experiment flown in Biorack during the Spacelab D1 Mission. An added feature of the experiment for the First International Microgravity Laboratory (IML-1) Mission is to study the effect of microgravity on the life span of Drosophila male flies. Various aspects of the investigation are discussed.

POLLUTION PREVENTION OPPORTUNITY ASSESSMENT HISTOLOGY LABORATORY XYLENE USE - FORT CARSON, COLORADO

EPA Science Inventory

Under the WREAFS program, RREL has performed a waste minimization opportunity assessment (WMOA) at the Evans Community Hospital Histopathology Laboratory on the Ft. Carson Army Base, Colorado, in the area of waste xylene and ethyl alcohol contaminated with human tissue. The waste...

Biofiltration of xylene using wood charcoal as the biofilter media under transient and high loading conditions.

PubMed

Singh, Kiran; Giri, B S; Sahi, Amrita; Geed, S R; Kureel, M K; Singh, Sanjay; Dubey, S K; Rai, B N; Kumar, Surendra; Upadhyay, S N; Singh, R S

2017-10-01

The main objective of this study was to evaluate the performance of wood charcoal as biofilter media under transient and high loading condition. Biofiltration of xylene was investigated for 150days in a laboratory scale unit packed with wood charcoal and inoculated with mixed microbial culture at the xylene loading rates ranged from 12 to 553gm -3 h -1 . The kinetic analysis of the xylene revealed absence of substrate inhibition and possibility of achieving higher elimination under optimum condition. The pH, temperature, pressure drop and CO 2 production rate were regularly monitored during the experiments. Throughout experimental period, the removal efficiency (RE) was found to be in the range of 65-98.7% and the maximum elimination capacity (EC) was 405.7gm -3 h -1 . Molecular characterization results show Bacillus sp. as dominating microbial group in the biofilm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exposure to Concentrated Ambient PM2.5 Shortens Lifespan and Induces Inflammation-Associated Signaling and Oxidative Stress in Drosophila.

PubMed

Wang, Xiaoke; Chen, Minjie; Zhong, Mianhua; Hu, Ziying; Qiu, Lianglin; Rajagopalan, Sanjay; Fossett, Nancy G; Chen, Lung-Chi; Ying, Zhekang

2017-03-01

Exposure to ambient PM 2.5 is associated with human premature mortality. However, it has not yet been toxicologically replicated, likely due to the lack of suitable animal models. Drosophila is frequently used in longevity research due to many incomparable merits. The present study aims to validate Drosophila models for PM 2.5 toxicity study through characterizing their biological responses to exposure to concentrated ambient PM 2.5 (CAP). The survivorship curve demonstrated that exposure to CAP markedly reduced lifespan of Drosophila. This antilongevity effect of CAP exposure was observed in both male and female Drosophila, and by comparison, the male was more sensitive [50% survivals: 20 and 48 days, CAP- and filtered air (FA)-exposed males, respectively; 21 and 40 days, CAP- and FA-exposed females, respectively]. Similar to its putative pathogenesis in humans, CAP exposure-induced premature mortality in Drosophila was also coincided with activation of pro-inflammatory signaling pathways including Jak, Jnk, and Nf-κb and increased systemic oxidative stress. Furthermore, like in humans and mammals, exposure to CAP significantly increased whole-body and circulating glucose levels and increased mRNA expression of Ilp2 and Ilp5 , indicating that CAP exposure induces dysregulated insulin signaling in Drosophila. Similar to effects on humans exposure to CAP leads to premature mortality likely through induction of inflammation-associated signaling, oxidative stress, and metabolic abnormality in Drosophila, strongly supporting that it can be a useful model organism for PM 2.5 toxicity study. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Analysis of the gene cluster encoding toluene/o-xylene monooxygenase from Pseudomonas stutzeri OX1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertoni, G.; Martino, M.; Galli, E.

The toluene/o-xylene monooxygenase cloned from Pseudomonas stutzeri OX1 displays a very broad range of substrates and a very peculiar regioselectivity, because it is able to hydroxylate more than one position on the aromatic ring of several hydrocarbons and phenols. The nucleotide sequence of the gene cluster coding for this enzymatic system has been determined. The sequence analysis revealed the presence of six open reading frames (ORFs) homologous to other genes clustered in operons coding for multicomponent monooxygenases found in benzene- and toluene-degradative pathways cloned from Pseudomonas strains. Significant similarities were also found with multicomponent monooxygenase systems for phenol, methane, alkene,more » and dimethyl sulfide cloned from different bacterial strains. The knockout of each ORF and complementation with the wild-type allele indicated that all six ORFs are essential for the full activity of the toluene/o-xylene monooxygenase in Escherichia coli. This analysis also shows that despite its activity on both hydrocarbons and phenols, toluene/o-xylene monooxygenase belongs to a toluene multicomponent monooxygenase subfamily rather than to the monooxygenases active on phenols.« less

Removal of p-xylene from an air stream in a hybrid biofilter.

PubMed

Wu, Dan; Quan, Xie; Zhao, Yazhi; Chen, Shuo

2006-08-21

Biofiltration of an air stream containing p-xylene has been studied in a laboratory hybrid biofilter packed with a mixture of mature pig compost, forest soil and the packing material which was made of polyethylene (PE) and used in the moving bed biological reactor (MBBR) in wastewater treatment. Three flow rates, 9.17, 19.87 and 40.66 m(3)m(-2)h(-1), were investigated for p-xylene inlet concentration ranging from 0.1 to 3.3 g m(-3). A high elimination capacity of 80 g m(-3)h(-1) corresponding to removal efficiency of 96% was obtained at a flow rate of 9.17 m(3)m(-2)h(-1) (empty bed residence time of 132 s). At a flow rate of 40.66 m(3)m(-2)h(-1) (empty bed residence time of 30s), the maximum elimination capacity for p-xylene was 40 g m(-3)h(-1) and removal efficiencies were in the range of 47-100%. The production of carbon dioxide (P(CO(2))) is proportional to elimination capacity (EC) and the linear relation was formulated as P(CO(2))=1.65EC+15.58. Stable pH values ranging from 6.3 to 7.6 and low pressure drop values less than 0.2 cm H(2)O (19.6 Pa) of packing media in compost-based biofilter of hybrid biofilter were observed, which avoided acidification and compaction of packing media and sustained the activity of microorganism populations.

Drosophila melanogaster mounts a unique immune response to the Rhabdovirus sigma virus.

PubMed

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

2008-05-01

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.

Drosophila melanogaster Mounts a Unique Immune Response to the Rhabdovirus Sigma virus▿

PubMed Central

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

Physiological, anatomical, and behavioral changes after acoustic trauma in Drosophila melanogaster

PubMed Central

Christie, Kevin W.; Sivan-Loukianova, Elena; Smith, Wesley C.; Aldrich, Benjamin T.; Schon, Michael A.; Roy, Madhuparna; Lear, Bridget C.; Eberl, Daniel F.

2013-01-01

Noise-induced hearing loss (NIHL) is a growing health issue, with costly treatment and lost quality of life. Here we establish Drosophila melanogaster as an inexpensive, flexible, and powerful genetic model system for NIHL. We exposed flies to acoustic trauma and quantified physiological and anatomical effects. Trauma significantly reduced sound-evoked potential (SEP) amplitudes and increased SEP latencies in control genotypes. SEP amplitude but not latency effects recovered after 7 d. Although trauma produced no gross morphological changes in the auditory organ (Johnston’s organ), mitochondrial cross-sectional area was reduced 7 d after exposure. In nervana 3 heterozygous flies, which slightly compromise ion homeostasis, trauma had exaggerated effects on SEP amplitude and mitochondrial morphology, suggesting a key role for ion homeostasis in resistance to acoustic trauma. Thus, Drosophila exhibit acoustic trauma effects resembling those found in vertebrates, including inducing metabolic stress in sensory cells. This report of noise trauma in Drosophila is a foundation for studying molecular and genetic sequelae of NIHL. PMID:24003166

Low doses of paraquat and polyphenols prolong life span and locomotor activity in knock-down parkin Drosophila melanogaster exposed to oxidative stress stimuli: implication in autosomal recessive juvenile parkinsonism.

PubMed

Bonilla-Ramirez, Leonardo; Jimenez-Del-Rio, Marlene; Velez-Pardo, Carlos

2013-01-10

Previous studies have shown that polyphenols might be potent neuroprotective agents in Drosophila melanogaster wild type Canton-S acutely or chronically treated with paraquat (PQ), a selective toxin for elimination of dopaminergic (DAergic) neurons by oxidative stress (OS), as model of Parkinson's disease (PD). This study reports for the first time that knock-down (K-D) parkin Drosophila melanogaster (TH-GAL4; UAS-RNAi-parkin) chronically exposed to PQ (0.1-0.25 mM), FeSO(4) (Fe, 0.1mM), deferoxamine (DFO, 0.01 mM) alone or (0.1mM) PQ in combination with polyphenols propyl gallate (PG, 0.1mM) and epigallocathecin gallate (EGCG, 0.1, 0.5mM) showed significantly higher life span and locomotor activity than untreated K-D flies or treated with (1, 5, 20mM) PQ alone. Whilst gallic acid (GA, 0.1, 0.5mM) alone or in the presence of PQ provoked no effect on K-D flies, epicathecin (EC, 0.5mM) only showed a positive effect on prolonging K-D flies' life span. It is shown that PG (and EGCG) protected protocerebral posterolateral 1 (PPL1) DAergic neurons against PQ. Interestingly, the protective effect of low PQ concentrations, DFO and iron might be explained by a phenomenon known as "hormesis." However, pre-fed K-D flies with (0.1mM) PQ for 7 days and then exposed to (0.25 mM) for additional 8 days affect neither survival nor climbing of K-D Drosophila compared to flies treated with (0.25 mM) PQ alone. Remarkably, K-D flies treated with 0.1mM PQ (7 days) and then with (0.25 mM) PQ plus PG (8 days) behaved almost as flies treated with (0.25 mM) PQ. Taken these data suggest that antioxidant supplements that synergistically act with low pro-oxidant stimuli to prolong and increase locomotor activity become inefficient once a threshold of OS has been reached in K-D flies. Our present findings support the notion that genetically altered Drosophila melanogaster as suitable model to study genetic and environmental factors as causal and/or modulators in the development of autosomal

Low-dose radiation induces Drosophila innate immunity through Toll pathway activation.

PubMed

Seong, Ki Moon; Kim, Cha Soon; Lee, Byung-Sub; Nam, Seon Young; Yang, Kwang Hee; Kim, Ji-Young; Park, Joong-Jean; Min, Kyung-Jin; Jin, Young-Woo

2012-01-01

Numerous studies report that exposing certain organisms to low-dose radiation induces beneficial effects on lifespan, tumorigenesis, and immunity. By analyzing survival after bacterial infection and antimicrobial peptide gene expression in irradiated flies, we demonstrate that low-dose irradiation of Drosophila enhances innate immunity. Low-dose irradiation of flies significantly increased resistance against gram-positive and gram-negative bacterial infections, as well as expression of several antimicrobial peptide genes. Additionally, low-dose irradiation also resulted in a specific increase in expression of key proteins of the Toll signaling pathway and phosphorylated forms of p38 and JNK. These results indicate that innate immunity is activated after low-dose irradiation through Toll signaling pathway in Drosophila.

Anaerobic Degradation of Benzene, Toluene, Ethylbenzene, and o-Xylene in Sediment-Free Iron-Reducing Enrichment Cultures

PubMed Central

Jahn, Michael K.; Haderlein, Stefan B.; Meckenstock, Rainer U.

2005-01-01

Monoaromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene (BTEX) are widespread contaminants in groundwater. We examined the anaerobic degradation of BTEX compounds with amorphous ferric oxide as electron acceptor. Successful enrichment cultures were obtained for all BTEX substrates both in the presence and absence of AQDS (9,10-anthraquinone-2,6-disulfonic acid). The electron balances showed a complete anaerobic oxidation of the aromatic compounds to CO2. This is the first report on the anaerobic degradation of o-xylene and ethylbenzene in sediment-free iron-reducing enrichment cultures. PMID:15933041

Rise of inhaled toluene, ethyl benzene, m-xylene, or mesitylene in rat blood after treatment with ethanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roemer, K.G.; Federsel, R.J.; Freundt, K.J.

Toluene, ethyl benzene, m-xylene, and mesitylene (1,3,5-methyl benzene) are widespread as solvents in industries and laboratories or in the manufacture and application of glues, paints, printing inks etc. These aromatics may be absorbed by employees during exposure at the workplace. Alcoholic beverages may be consumed during occupational inhalation or after shift's end at times. Toxicokinetic interactions between the aromatics and ethanol must be assumed because of the common pathway of biotransformation. The blood levels of toluene and m-xylene after inhalation increased significantly in volunteers dosed simultaneously with ethanol. In this view the present experiments in rats should elucidate whether themore » blood concentrations of inhaled ethyl benzene and mesitylene (both structurally related to toluene and m-xylene) can rise under the influence of ethanol, and whether quantitative differences of this effect due to the structure of these aromatics can occur. From the results informations important for the assessment of occupational health risk are to be expected.« less

Optimized RNA ISH, RNA FISH and protein-RNA double labeling (IF/FISH) in Drosophila ovaries

PubMed Central

Zimmerman, Sandra G; Peters, Nathaniel C; Altaras, Ariel E; Berg, Celeste A

2014-01-01

In situ hybridization (ISH) is a powerful technique for detecting nucleic acids in cells and tissues. Here we describe three ISH procedures that are optimized for Drosophila ovaries: whole-mount, digoxigenin-labeled RNA ISH; RNA fluorescent ISH (FISH); and protein immunofluorescence (IF)–RNA FISH double labeling (IF/FISH). Each procedure balances conflicting requirements for permeabilization, fixation and preservation of antigenicity to detect RNA and protein expression with high resolution and sensitivity. The ISH protocol uses alkaline phosphatase–conjugated digoxigenin antibodies followed by a color reaction, whereas FISH detection involves tyramide signal amplification (TSA). To simultaneously preserve antigens for protein detection and enable RNA probe penetration for IF/FISH, we perform IF before FISH and use xylenes and detergents to permeabilize the tissue rather than proteinase K, which can damage the antigens. ISH and FISH take 3 d to perform, whereas IF/FISH takes 5 d. Probe generation takes 1 or 2 d to perform. PMID:24113787

Biofiltration and inhibitory interactions of gaseous benzene, toluene, xylene, and methyl tert-butyl ether.

PubMed

Shim, Eun-Hwa; Kim, Jaisoo; Cho, Kyung-Suk; Ryu, Hee Wook

2006-05-01

This study evaluated the individual and combined removal capacities of benzene, toluene, and xylene (B, T, and X) in the presence and absence of methyl tert-butyl ether (MTBE) in a polyurethane biofilter inoculated with a BTX-degrading microbial consortium, and further examined their interactive effects in various mixtures. In addition, Polymerase chain reaction-denaturing gradient gel electrophoresis and phylogenetic analysis of 16S rRNA gene sequences were used to compare the microbial community structures found in biofilters exposed to the various gases and gas mixtures. The maximum individual elimination capacities (MECs) of B, T, and X were 200, 238, and 400 g m(-3) h(-1), respectively. There was no significant elimination of MTBE alone. Addition of MTBE decreased the MECs of B,T, and X to 75, 100, and 300 g m(-3) h(-1), respectively, indicating that benzene was most strongly inhibited by MTBE. When the three gases were mixed (B + T + X), the removal capacities of individual B, T, and X were 50, 90, and 200 g m(-3) h(-1), respectively. These capacities decreased to 40, 50, and 100 g m(-3) h(-1) when MTBE was added to the mix. The MEC of the three-gas mixture (B + T + X) was 340 g m(-3) h(-1), and that of the four-gas mixture was 200 g m(-3) h(-1). Although MTBE alone was not degraded by the biofilter, it could be co-metabolically degraded in the presence of toluene, benzene, or xylene with the MECs of 34, 23, and 14 g m(-3) h(-1), respectively. The microbial community structure analysis revealed that two large groups could be distinguished based on the presence or absence of MTBE, and many of the dominant bacteria in the consortia were closely related to bacteria isolated from aromatic hydrocarbon-contaminated sites and/ or oil wastewaters. These findings provide important new insights into biofiltration and may be used to improve the rational design of biofilters for remediation of petroleum gas-contaminated airstreams according to composition types of mixed

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

PubMed

Cowles, Richard S; Rodriguez-Saona, Cesar; Holdcraft, Robert; Loeb, Gregory M; Elsensohn, Johanna E; Hesler, Steven P

2015-04-01

The addition of sucrose to insecticides targeting spotted wing drosophila, Drosophila suzukii (Matsumura), enhanced lethality in laboratory, semifield, and field tests. In the laboratory, 0.1% sucrose added to a spray solution enhanced spotted wing drosophila feeding. Flies died 120 min earlier when exposed to spinosad residues at label rates enhanced with sucrose. Added sucrose reduced the LC50 for dried acetamiprid residues from 82 to 41 ppm in the spray solution. Laboratory bioassays of spotted wing drosophila mortality followed exposure to grape and blueberry foliage and/or fruit sprayed and aged in the field. On grape foliage, the addition of 2.4 g/liter of sugar with insecticide sprays resulted in an 11 and 6% increase of spotted wing drosophila mortality at 1 and 2 d exposures to residues, respectively, averaged over seven insecticides with three concentrations. In a separate experiment, spinetoram and cyantraniliprole reduced by 95-100% the larval infestation of blueberries, relative to the untreated control, 7 d after application at labeled rates when applied with 1.2 g/liter sucrose in a spray mixture, irrespective of rainfall; without sucrose infestation was reduced by 46-91%. Adding sugar to the organically acceptable spinosyn, Entrust, reduced larval infestation of strawberries by >50% relative to without sugar for five of the six sample dates during a season-long field trial. In a small-plot field test with blueberries, weekly applications in alternating sprays of sucrose plus reduced-risk insecticides, spinetoram or acetamiprid, reduced larval infestation relative to the untreated control by 76%; alternating bifenthrin and phosmet (without sucrose) reduced infestation by 65%. © 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.

Conversion Characteristics and Production Evaluation of Styrene/o-Xylene Mixtures Removed by DBD Pretreatment

PubMed Central

Jiang, Liying; Zhu, Runye; Mao, Yubo; Chen, Jianmeng; Zhang, Liang

2015-01-01

The combination of chemical oxidation methods with biotechnology to removal recalcitrant VOCs is a promising technology. In this paper, the aim was to identify the role of key process parameters and biodegradability of the degradation products using a dielectric barrier discharge (DBD) reactor, which provided the fundamental data to evaluate the possibilities of the combined system. Effects of various technologic parameters like initial concentration of mixtures, residence time and relative humidity on the decomposition and the degradation products were examined and discussed. It was found that the removal efficiency of mixed VOCs decreased with increasing initial concentration. The removal efficiency reached the maximum value as relative humidity was approximately 40%–60%. Increasing the residence time resulted in increasing the removal efficiency and the order of destruction efficiency of VOCs followed the order styrene > o-xylene. Compared with the single compounds, the removal efficiency of styrene and o-xylene in the mixtures of VOCs decreased significantly and o-xylene decreased more rapidly. The degradation products were analyzed by gas chromatography and gas chromatography-mass spectrometry, and the main compounds detected were O3, COx and benzene ring derivatives. The biodegradability of mixed VOCs was improved and the products had positive effect on biomass during plasma application, and furthermore typical results indicated that the biodegradability and biotoxicity of gaseous pollutant were quite depending on the specific input energy (SIE). PMID:25629961

Problem Definition Studies on Potential Environmental Pollutants. 4. Physical, Chemical, Toxicological, and Biological Properties of Benzene; Toluene; Xylenes; and para-Chlorophenyl Methyl Sulfide, Sulfoxide, and Sulfone

DTIC Science & Technology

1976-06-01

ecological hazards of benzene, toluene, xylenes,* and p-chlorophenyl methyl sulfide, sulfoxide, and sulfone at Rocky Mountain Arsenal (RMA). That assessment...recently reviewed the occupational hazard associated with the use of benzene, toluene, and xylene and has recomiended the folcwln !.ImitS In workroom air...Toxicology and Ecological Hazards of "Venzene; Toluene; Xylenes; and p-Chlorophenyl Methyl Sulfide, Sulfoxide, and Sulfone at Rocky tc-cntain Arsenal

Investigating the effects of nanoparticles on reproduction and development in Drosophila melanogaster and CD-1 mice

NASA Astrophysics Data System (ADS)

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

Silver nanoparticles disrupt germline stem cell maintenance in the Drosophila testis

NASA Astrophysics Data System (ADS)

Ong, Cynthia; Lee, Qian Ying; Cai, Yu; Liu, Xiaoli; Ding, Jun; Yung, Lin-Yue Lanry; Bay, Boon-Huat; Baeg, Gyeong-Hun

2016-02-01

Silver nanoparticles (AgNPs), one of the most popular nanomaterials, are commonly used in consumer products and biomedical devices, despite their potential toxicity. Recently, AgNP exposure was reported to be associated with male reproductive toxicity in mammalian models. However, there is still a limited understanding of the effects of AgNPs on spermatogenesis. The fruit fly Drosophila testis is an excellent in vivo model to elucidate the mechanisms underlying AgNP-induced defects in spermatogenesis, as germ lineages can be easily identified and imaged. In this study, we evaluated AgNP-mediated toxicity on spermatogenesis by feeding Drosophila with AgNPs at various concentrations. We first observed a dose-dependent uptake of AgNPs in vivo. Concomitantly, AgNP exposure caused a significant decrease in the viability and delay in the development of Drosophila in a dose-dependent manner. Furthermore, AgNP-treated male flies showed a reduction in fecundity, and the resulting testes contained a decreased number of germline stem cells (GSCs) compared to controls. Interestingly, testes exposed to AgNPs exhibited a dramatic increase in reactive oxygen species levels and showed precocious GSC differentiation. Taken together, our study suggests that AgNP exposure may increase ROS levels in the Drosophila testis, leading to a reduction of GSC number by promoting premature GSC differentiation.

Electrophysiological Recordings from Lobula Plate Tangential Cells in Drosophila.

PubMed

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.

Maternal control of the Drosophila dorsal–ventral body axis

PubMed Central

Stein, David S.; Stevens, Leslie M.

2016-01-01

The pathway that generates the dorsal–ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity. PMID:25124754

Naltrexone Reverses Ethanol Preference and Protein Kinase C Activation in Drosophila melanogaster

PubMed Central

Koyyada, Rajeswari; Latchooman, Nilesh; Jonaitis, Julius; Ayoub, Samir S.; Corcoran, Olivia; Casalotti, Stefano O.

2018-01-01

Alcohol use disorder (AUD) is a major health, social and economic problem for which there are few effective treatments. The opiate antagonist naltrexone is currently prescribed clinically with mixed success. We have used naltrexone in an established behavioral assay (CAFE) in Drosophila melanogaster that measures the flies' preference for ethanol-containing food. We have confirmed that Drosophila exposed to ethanol develop a preference toward this drug and we demonstrate that naltrexone, in a dose dependant manner, reverses the ethanol-induced ethanol preference. This effect is not permanent, as preference for alcohol returns after discontinuing naltrexone. Additionally, naltrexone reduced the alcohol-induced increase in protein kinase C activity. These findings are of interest because they confirm that Drosophila is a useful model for studying human responses to addictive drugs. Additionally because of the lack of a closely conserved opiate system in insects, our results could either indicate that a functionally related system does exist in insects or that in insects, and potentially also in mammals, naltrexone binds to alternative sites. Identifying such sites could lead to improved treatment strategies for AUD. PMID:29593550

Simulation chamber studies of the atmospheric degradation of xylene oxidation products

NASA Astrophysics Data System (ADS)

Clifford, G.; Rea, G.; Thuener, L.; Wenger, J.

2003-04-01

Aromatic compounds are emitted to the atmosphere from their use in automobile fuels and solvents. In addition to being important primary pollutants, many aromatics, including the xylenes, possess high photochemical reactivity and make a major contribution to the formation of oxidants, such as ozone and nitrates, in the troposphere. The atmospheric oxidation of aromatics produces a wide variety of products and the atmospheric reactivity of many of these species is unknown. The aim of this work was to study the atmospheric degradation processes for dimethylphenols, tolualdehydes and dicarbonyl compounds which are produced from the hydroxyl radical initiated oxidation of the xylenes. Experiments on the hydroxyl (OH) and nitrate radical initiated oxidation of dimethylphenols and tolualdehydes have been performed in a large atmospheric simulation chamber in our laboratory. The chamber is made of FEP foil and has a volume of about 4750 litres. It is equipped with gas chromatography, GC-MS, and in situ FTIR spectroscopy for chemical analysis and a scanning mobility particle sizer for aerosol measurements. Rate coefficients have been determined for the reactions of hydroxyl and nitrate radicals with dimethylphenols and tolualdehydes. Gas-phase products and the yield of secondary organic aerosol have also been determined for the OH-initiated oxidation of these compounds. Mechanisms for the formation of the products are proposed. The photolysis of the unsaturated dicarbonyls, butenedial and 4-oxo-pent-2-enal, has been studied using real sunlight at the European Photoreactor (EUPHORE) in Valencia, Spain. Photolysis rates were measured and indicate that photolysis by sunlight is the major atmospheric degradation process for these compounds. Product studies show the formation of a ketene intermediate that decays to form five membered ring compounds such as furanones and maleic anhydride. Mechanisms for the formation of the products are proposed. Finally, the data obtained in

Signaling Pathways Involved in 1-Octen-3-ol-Mediated Neurotoxicity in Drosophila melanogaster: Implication in Parkinson’s Disease

PubMed Central

Masurekar, Prakash; Hossain, Muhammad; Richardson, Jason R.; Bennett, Joan W.

2014-01-01

Previously, we have pioneered Drosophila melanogaster as a reductionist model to show that 1-octen-3-ol, a musty-smelling volatile compound emitted by fungi and other organisms, causes loss of dopaminergic neurons and Parkinson’s disease-like symptoms in flies. Using our in vivo Drosophila system, the modulatory roles of important signaling pathways—JNK, Akt and the caspase-3-dependent apoptotic pathway were investigated in the context of 1-octen-3-ol-induced dopamine neurotoxicity. When heterozygous flies carrying mutant alleles for these proteins were exposed to 0.5 ppm of 1-octen-3-ol, they had shorter survival times than wild-type Drosophila. The overexpressed levels of wild-type JNK and Akt, (UAS-bsk and UAS-Akt) with TH-GAL4 and elav-GAL4 drivers improved the survival duration of exposed flies compared with controls. Thus, we found that Akt and JNK both protect against loss of dopamine activity associated with 1-octen-3-ol exposure, indicating the pro-survival role of these signaling pathways. Further, 1-octen-3-ol exposure was associated with activation of caspase 3, a hallmark for apoptosis. PMID:23959949

Quantification of biodegradation for o-xylene and naphthalene using first order decay models, Michaelis-Menten kinetics and stable carbon isotopes.

PubMed

Blum, Philipp; Hunkeler, Daniel; Weede, Matthias; Beyer, Christof; Grathwohl, Peter; Morasch, Barbara

2009-04-01

At a former wood preservation plant severely contaminated with coal tar oil, in situ bulk attenuation and biodegradation rate constants for several monoaromatic (BTEX) and polyaromatic hydrocarbons (PAH) were determined using (1) classical first order decay models, (2) Michaelis-Menten degradation kinetics (MM), and (3) stable carbon isotopes, for o-xylene and naphthalene. The first order bulk attenuation rate constant for o-xylene was calculated to be 0.0025 d(-1) and a novel stable isotope-based first order model, which also accounted for the respective redox conditions, resulted in a slightly smaller biodegradation rate constant of 0.0019 d(-1). Based on MM-kinetics, the o-xylene concentration decreased with a maximum rate of k(max)=0.1 microg/L/d. The bulk attenuation rate constant of naphthalene retrieved from the classical first order decay model was 0.0038 d(-1). The stable isotope-based biodegradation rate constant of 0.0027 d(-1) was smaller in the reduced zone, while residual naphthalene in the oxic part of the plume further downgradient was degraded at a higher rate of 0.0038 d(-1). With MM-kinetics a maximum degradation rate of k(max)=12 microg/L/d was determined. Although best fits were obtained by MM-kinetics, we consider the carbon stable isotope-based approach more appropriate as it is specific for biodegradation (not overall attenuation) and at the same time accounts for the dominant electron-accepting process. For o-xylene a field based isotope enrichment factor epsilon(field) of -1.4 could be determined using the Rayleigh model, which closely matched values from laboratory studies of o-xylene degradation under sulfate-reducing conditions.

Phosphatidylserine recognition and induction of apoptotic cell clearance by Drosophila engulfment receptor Draper.

PubMed

Tung, Tran Thanh; Nagaosa, Kaz; Fujita, Yu; Kita, Asana; Mori, Hiroki; Okada, Ryo; Nonaka, Saori; Nakanishi, Yoshinobu

2013-05-01

The membrane phospholipid phosphatidylserine is exposed on the cell surface during apoptosis and acts as an eat-me signal in the phagocytosis of apoptotic cells in mammals and nematodes. However, whether this is also true in insects was unclear. When milk fat globule-epidermal growth factor 8, a phosphatidylserine-binding protein of mammals, was ectopically expressed in Drosophila, the level of phagocytosis was reduced, whereas this was not the case for the same protein lacking a domain responsible for the binding to phosphatidylserine. We found that the extracellular region of Draper, an engulfment receptor of Drosophila, binds to phosphatidylserine in an enzyme-linked immunosorbent assay-like solid-phase assay and in an assay for surface plasmon resonance. A portion of Draper containing domains EMI and NIM located close to the N-terminus was required for binding to phosphatidylserine, and a Draper protein lacking this region was not active in Drosophila. Finally, the level of tyrosine-phosphorylated Draper, indicative of the activation of Draper, in a hemocyte-derived cell line was increased after treatment with phosphatidylserine-containing liposome. These results indicated that phosphatidylserine serves as an eat-me signal in the phagocytic removal of apoptotic cells in Drosophila and that Draper is a phosphatidylserine-binding receptor for phagocytosis.

Transcriptomic response of Drosophila melanogaster pupae developed in hypergravity.

PubMed

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

2016-10-01

Altered gravity can perturb normal development and induce corresponding changes in gene expression. Understanding this relationship between the physical environment and a biological response is important for NASA's space travel goals. We use RNA-Seq and qRT-PCR techniques to profile changes in early Drosophila melanogaster pupae exposed to chronic hypergravity (3g, or three times Earth's gravity). During the pupal stage, D. melanogaster rely upon gravitational cues for proper development. Assessing gene expression changes in the pupae under altered gravity conditions helps highlight gravity-dependent genetic pathways. A robust transcriptional response was observed in hypergravity-treated pupae compared to controls, with 1513 genes showing a significant (q<0.05) difference in gene expression. Five major biological processes were affected: ion transport, redox homeostasis, immune response, proteolysis, and cuticle development. This outlines the underlying molecular and biological changes occurring in Drosophila pupae in response to hypergravity; gravity is important for many biological processes on Earth. Published by Elsevier Inc.

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

PubMed

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.

Semen quality of workers occupationally exposed to hydrocarbons.

PubMed

De Celis, R; Feria-Velasco, A; González-Unzaga, M; Torres-Calleja, J; Pedrón-Nuevo, N

2000-02-01

To determine whether occupational exposure of men to hydrocarbons has adverse effects on the quality of their semen. Comparative study. The rubber industry in Mexico City. Forty-eight workers who were exposed to hydrocarbons for 2-24 years and 42 unexposed workers. None. Environmental hydrocarbon concentrations were determined by continuous air monitoring in all areas of the factory. Analyses of semen samples were performed in accordance with World Health Organization criteria. Hydrocarbon concentrations were as follows: ethylbenzene, 220.7-234 mg/m3; benzene, 31.9-47.8 mg/m3; toluene, 189.7-212.5 mg/m3; and xylene, 47-56.4 mg/m3. The number of subjects with ejaculates that had normal characteristics was greater in the unexposed group (76%) than in the exposed group (17%). More abnormal characteristics were found in the semen of exposed workers than unexposed workers, including alterations in viscosity, liquefaction capacity, sperm count, sperm motility, and the proportion of sperm with normal morphology. Some abnormal characteristics correlated with the number of years of exposure to the hydrocarbons. Damage to the spermatogenic process resulting from hydrocarbon exposure was demonstrated by an increased rate of abnormalities in the semen of exposed workers compared with unexposed workers. This information may be useful for conducting future analyses of reproductive risks related to exposure to high concentrations of hydrocarbons.

Characterization of Deuterated-xylene Scintillator as a Neutron Spectrometer

DOE PAGES

Di Fulvio, Angela; Becchetti, F. D.; Raymond, R. S.; ...

2016-11-16

We have experimentally characterized the neutron light output response functions of a deuterated-xylene scintillator for neutron energies lower than 10 MeV. We then used the response matrix to unfold the energy distribution of neutrons produced via several reactions, i.e. spontaneous fission, d(d,n)3He, 27Al(d,n)28Si, and 9Be(alpha,n)12C. Organic scintillators based on deuterated compounds show a fast response and good gamma-neutron discrimination capability, similar to proton-based scintillators. Deuterated scintillators can also effectively provide neutron spectra by unfolding measured data with the detector response matrix, without the need of time-of-flight. Deuteron recoils, produced by elastic collisions between deuterium and impinging neutrons, are preferentially forward-scattered.more » This non-isotropic reaction results in distinct peaks in the response functions to monoenergetic neutrons. In this work, we evaluated a custom-fabricated 7.62 cm x 7.62 cm deuterated-xylene (EJ301D) liquid scintillator. This liquid has a low volatility and higher flash point, compared to benzene-based deuterated detectors, e.g. EJ315 and NE230. We measured the EJ301D detector neutron response matrix (up to 6 MeV neutron energy) using an intense Cf252 source and the time-of-flight technique. The number of response functions obtained using our method is only limited by counting statistics and by the experimentally achievable energy resolution. Multi-channel unfolding was performed successfully for neutron spectra with different energy spectra.« less

Modeling Human Cancers in Drosophila.

PubMed

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.

Semi-automated quantitative Drosophila wings measurements.

PubMed

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.

Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function.

PubMed

Adolfsson, Karl; Schneider, Martina; Hammarin, Greger; Häcker, Udo; Prinz, Christelle N

2013-07-19

Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III-V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate.

Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function

NASA Astrophysics Data System (ADS)

Adolfsson, Karl; Schneider, Martina; Hammarin, Greger; Häcker, Udo; Prinz, Christelle N.

2013-07-01

Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III-V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate.

Drosophila's contribution to stem cell research.

PubMed

Singh, Gyanesh

2015-01-01

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.

Drosophila's contribution to stem cell research

PubMed Central

Singh, Gyanesh

2016-01-01

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. PMID:26180635

Autophagy in Drosophila melanogaster.

PubMed

McPhee, Christina K; Baehrecke, Eric H

2009-09-01

Macroautophagy (autophagy) is a bulk cytoplasmic degradation process that is conserved from yeast to mammals. Autophagy is an important cellular response to starvation and stress, and plays critical roles in development, cell death, aging, immunity, and cancer. The fruit fly Drosophila melanogaster provides an excellent model system to study autophagy in vivo, in the context of a developing organism. Autophagy (atg) genes and their regulators are conserved in Drosophila, and autophagy is induced in response to nutrient starvation and hormones during development. In this review we provide an overview of how Drosophila research has contributed to our understanding of the role and regulation of autophagy in cell survival, growth, nutrient utilization, and cell death. Recent Drosophila research has also provided important mechanistic information about the role of autophagy in protein aggregation disorders, neurodegeneration, aging, and innate immunity. Differences in the role of autophagy in specific contexts and/or cell types suggest that there may be cell-context-specific regulators of autophagy, and studies in Drosophila are well-suited to yield discoveries about this specificity.

Anaerobic Degradation of Benzene, Toluene, Ethylbenzene, and Xylene Compounds by Dechloromonas Strain RCB

PubMed Central

Chakraborty, Romy; O'Connor, Susan M.; Chan, Emily; Coates, John D.

2005-01-01

Dechloromonas strain RCB has been shown to be capable of anaerobic degradation of benzene coupled to nitrate reduction. As a continuation of these studies, the metabolic versatility and hydrocarbon biodegradative capability of this organism were investigated. The results of these revealed that in addition to nitrate, strain RCB could alternatively degrade benzene both aerobically and anaerobically with perchlorate or chlorate [(per)chlorate] as a suitable electron acceptor. Furthermore, with nitrate as the electron acceptor, strain RCB could also utilize toluene, ethylbenzene, and all three isomers of xylene (ortho-, meta-, and para-) as electron donors. While toluene and ethylbenzene were completely mineralized to CO2, strain RCB did not completely mineralize para-xylene but rather transformed it to some as-yet-unidentified metabolite. Interestingly, with nitrate as the electron acceptor, strain RCB degraded benzene and toluene concurrently when the hydrocarbons were added as a mixture and almost 92 μM total hydrocarbons were oxidized within 15 days. The results of these studies emphasize the unique metabolic versatility of this organism, highlighting its potential applicability to bioremediative technologies. PMID:16332859

Ionic liquid-based single-drop microextraction/gas chromatographic/mass spectrometric determination of benzene, toluene, ethylbenzene and xylene isomers in waters.

PubMed

Aguilera-Herrador, Eva; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

2008-08-01

The direct coupling between ionic liquid-based single-drop microextraction and gas chromatography/mass spectrometry is proposed for the rapid and simple determination of benzene, toluene, ethylbenzene and xylenes isomers (BTEX) in water samples. The extraction procedure exploits not only the high affinity of the selected ionic liquid (1-methyl-3-octyl-imidazolium hexaflourophosphate) to these aromatic compounds but also its special properties like viscosity, low vapour pressure and immiscibility with water. All the variables involved in the extraction process have been studied in depth. The developed method allows the determination of these single-ring compounds in water under the reference concentration level fixed by the international legislation. In this case, limits of detection were in the range 20 ng L(-1) (obtained for benzene) and 91 ng L(-1) (for o-xylene). The repeatability of the proposed method, expressed as RSD (n=5), varied between 3.0% (o-xylene) and 5.2% (toluene).

Effect of pretreatment on pd/Al2O3 catalyst for catalytic oxidation of o-xylene at low temperature.

PubMed

Huang, Shaoyong; Zhang, Changbin; He, Hong

2013-06-01

The effect of pretreatment on Pd/Al2O3 catalysts for the catalytic oxidation of o-xylene at low temperature was studied by changing the pretreatment and testing conditions. The fresh and pretreated Pd/Al2O3 catalysts were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results showed that the pretreatment dramatically changed the Pd/PdO ratio and then significantly affected the Pd/Al2O3 activity; while the pretreatment had not much influence on Pd particle size. The Pd/Al2O3 pre-reduced at 300 degrees C/400 degrees C, which has fully reduced Pd species, showed the highest activity; while the fresh Pd/Al2O3, which has fully oxidized Pd species, presented the worst performance, indicating the Pd chemical state plays an important role in the catalytic activity for the o-xylene oxidation. It is concluded that metallic Pd is the active species on the Pd/Al2O3 catalyst for the catalytic oxidation of o-xylene at low temperature.

Developing a Drosophila Model of Schwannomatosis

DTIC Science & Technology

2013-02-01

Drosophila melanogaster has become an important model system for cancer studies. Reduced redundancy in the Drosophila genome compared with that of...of high-resolution deletion coverage of the Drosophila melanogaster genome . Nat. Genet. 36, 288-292. Pastor-Pareja, J. C., Wu, M. and Xu. T. (2008...microarray analysis of the entire Drosophila melanogaster genome and compared gene expression profiles of wild type, dCap-D3 and rbf1 mutant

A dopamine receptor contributes to paraquat-induced neurotoxicity in Drosophila

PubMed Central

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

The Drosophila melanogaster host model

PubMed Central

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

2012-01-01

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

The Drosophila melanogaster host model.

PubMed

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.

Development of benzene, toluene, ethylbenzene and xylenes certified gaseous reference materials

NASA Astrophysics Data System (ADS)

Brum, M. C.; Sobrinho, D. C. G.; Fagundes, F. A.; Oudwater, R. J.; Augusto, C. R.

2016-07-01

The work describes the production of certified gaseous reference materials of benzene, toluene, ethylbenzene and xylenes (BTEX) in nitrogen from the gravimetric production up to the long term stability tests followed by the certifying step. The uncertainty in the amount fractions of the compounds in these mixtures was approximately 4% (relative) for the range studied from 2 to 16 µmol/mol. Also the adsorption of the BTEX on the cylinder surface and the tubing were investigated as potential uncertainty source.

Chronic unpredictable mild stress-induced depressive-like behavior and dysregulation of brain levels of biogenic amines in Drosophila melanogaster.

PubMed

Araujo, Stífani Machado; Poetini, Marcia Rósula; Bortolotto, Vandreza Cardoso; de Freitas Couto, Shanda; Pinheiro, Franciane Cabral; Meichtry, Luana Barreto; de Almeida, Francielli Polet; Santos Musachio, Elize Aparecida; de Paula, Mariane Trindade; Prigol, Marina

2018-05-24

The etiopathogenesis of depression may involve repeated exposure to several unpredictable stressors. This study was conducted to investigate changes induced by chronic unpredictable mild stress (CUMS) and to assess behavioral and neurochemical changes that predict depressive-like behavior in Drosophila melanogaster. Male Drosophila melanogaster flies were exposed to CUMS with several stressors (cold, heat, starvation, and sleep deprivation) in an unpredictable and chronic manner for ten days. At the end of treatment, in vivo behavioral tests (open field, aggression, forced swimming, mating, light/dark box, male fertility evaluation, sucrose preference, weight evaluation) and ex vivo analyses (dopamine and serotonin levels) were performed. Using this CUMS model, we obtained results that contribute to the construction of a depressive model in Drosophila, where we reproduce some behavioral phenotypes corresponding to depressive symptoms, such as immobility in the forced swimming test, less exploration in the light/dark test, changes in mating behavior, changes in the aggressiveness test, reduced sucrose preference, and weight-loss, in addition to a significant reduction in the levels of serotonin and dopamine when compared to the control group. Fluoxetine was used in our study as a positive control to demonstrate that CUMS-induced depressive-like behaviors in flies can be reversed by antidepressants. In conclusion, male Drosophila melanogaster exposed to CUMS display a depressive-like phenotype, and, while this poses some limitations as an animal model for depression, it meets some of the criteria required to be a valid model, such as good face and construct validity. Copyright © 2018. Published by Elsevier B.V.

Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate

PubMed Central

Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.

2012-01-01

Drosophila melanogaster adults and larvae, but especially larvae, had profound effects on the densities and community structure of yeasts that developed in banana fruits. Pieces of fruit exposed to adult female flies previously fed fly-conditioned bananas developed higher yeast densities than pieces of the same fruits that were not exposed to flies, supporting previous suggestions that adult Drosophila vector yeasts to new substrates. However, larvae alone had dramatic effects on yeast density and species composition. When yeast densities were compared in pieces of the same fruits assigned to different treatments, fruits that developed low yeast densities in the absence of flies developed significantly higher yeast densities when exposed to larvae. Across all of the fruits, larvae regulated yeast densities within narrow limits, as compared to a much wider range of yeast densities that developed in pieces of the same fruits not exposed to flies. Larvae also affected yeast species composition, dramatically reducing species diversity across fruits, reducing variation in yeast communities from one fruit to the next (beta diversity), and encouraging the consistent development of a yeast community composed of three species of yeast (Candida californica, C. zemplinina, and Pichia kluvyeri), all of which were palatable to larvae. Larvae excreted viable cells of these three yeast species in their fecal pools, and discouraged the growth of filamentous fungi, processes which may have contributed to their effects on the yeast communities in banana fruits. These and other findings suggest that D. melanogaster adults and their larval offspring together engage in ‘niche construction’, facilitating a predictable microbial environment in the fruit substrates in which the larvae live and develop. PMID:22860093

The Drosophila imd signaling pathway.

PubMed

Myllymäki, Henna; Valanne, Susanna; Rämet, Mika

2014-04-15

The fruit fly, Drosophila melanogaster, has helped us to understand how innate immunity is activated. In addition to the Toll receptor and the Toll signaling pathway, the Drosophila immune response is regulated by another evolutionarily conserved signaling cascade, the immune deficiency (Imd) pathway, which activates NF-κB. In fact, the Imd pathway controls the expression of most of the antimicrobial peptides in Drosophila; thus, it is indispensable for normal immunity in flies. In this article, we review the current literature on the Drosophila Imd pathway, with special emphasis on its role in the (patho)physiology of different organs. We discuss the systemic response, as well as local responses, in the epithelial and mucosal surfaces and the nervous system.

NiO/NiWO4 Composite Yolk-Shell Spheres with Nanoscale NiO Outer Layer for Ultrasensitive and Selective Detection of Subppm-level p-Xylene.

PubMed

Kim, Tae-Hyung; Kwak, Chang-Hoon; Lee, Jong-Heun

2017-09-20

NiO/NiWO 4 composite yolk-shell spheres with a nanoscale NiO outer layer were prepared using one-pot ultrasonic spray pyrolysis and their gas sensing characteristics were studied. The NiO/NiWO 4 yolk-shell spheres exhibited an extremely high response to 5 ppm p-xylene (ratio of resistance to gas and air = 343.5) and negligible cross-responses to 5 ppm ethanol, ammonia, carbon monoxide, hydrogen, and benzene, whereas pure NiO yolk-shell spheres showed very low responses and selectivity to all the analyte gases. The detection limit for p-xylene was as low as 22.7 ppb. This ultrasensitive and selective detection of p-xylene is attributed to a synergistic catalytic effect between NiO and NiWO 4 , high gas accessibility with large specific surface area, and increased chemiresistive variation due to the formation of a heterojunction. The NiO/NiWO 4 yolk-shell spheres with a thin NiO outer layer can be used to detect subppm-level p-xylene in a highly sensitive and selective manner for monitoring indoor air pollution.

Genome of Drosophila suzukii, the Spotted Wing Drosophila

PubMed Central

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

2013-01-01

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

Developing a Drosophila Model of Schwannomatosis

DTIC Science & Technology

2012-08-01

the entire Drosophila melanogaster genome and compared...et al., 2009; Hanahan and Weinberg, 2011). Over the last decade, the fruit fly Drosophila melanogaster has become an important model system for cancer...studies. Reduced redundancy in the Drosophila genome compared with that of humans, coupled with the ability to conduct large-scale genetic screens

Meiosis in male Drosophila

PubMed Central

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

2012-01-01

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

Improved assignments of the vibrational fundamental modes of ortho -, meta -, and para -xylene using gas- and liquid-phase infrared and Raman spectra combined with ab initio calculations: Quantitative gas-phase infrared spectra for detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindenmaier, Rodica; Scharko, Nicole K.; Tonkyn, Russell G.

Xylenes contain a blend of the ortho-, meta-, and para- isomers, and all are abundant contaminants in the ground, surface waters, and air. To better characterize xylene and to better enable its detection, we report high quality quantitative vapor-phase infrared spectra of all three isomers over the 540-6500 cm -1 range. All fundamental vibrational modes are assigned based on these vapor-phase infrared spectra, liquid-phase infrared and Raman spectra, along with density functional theory (DFT), ab initio MP2 and high energy-accuracy compound theoretical model (W1BD) calculations. Both MP2 and DFT predict a single conformer with C 2v symmetry for ortho-xylene, andmore » two conformers each for meta- and para-xylene, depending on the preferred orientations of the methyl groups. For meta-xylene the two conformers have C s and C 2 symmetry, and for para-xylene these conformers have C 2v or C 2h symmetry. Since the relative population of the two conformers is approximately 50% for both isomers and predicted frequencies and intensities are very similar for each conformer, we made an arbitrary choice to discuss the C s conformer for meta-xylene and the C 2v conformer for para-xylene. We report integrated band intensities for all isomers. Using the quantitative infrared data, we determine the global warming potential values of each isomer and discuss potential bands for atmospheric monitoring.« less

Improved assignments of the vibrational fundamental modes of ortho-, meta-, and para-xylene using gas- and liquid-phase infrared and Raman spectra combined with ab initio calculations: Quantitative gas-phase infrared spectra for detection

NASA Astrophysics Data System (ADS)

Lindenmaier, Rodica; Scharko, Nicole K.; Tonkyn, Russell G.; Nguyen, Kiet T.; Williams, Stephen D.; Johnson, Timothy J.

2017-12-01

Xylenes contain a blend of the ortho-, meta-, and para- isomers, and all are abundant contaminants in the ground, surface waters, and air. To better characterize xylene and to better enable its detection, high quality quantitative vapor-phase infrared spectra of all three isomers over the 6500 - 540 cm-1 range are reported. All fundamental vibrational modes are assigned based on these vapor-phase infrared spectra, liquid-phase infrared and Raman spectra, along with density functional theory (DFT), ab initio MP2 and high energy-accuracy compound theoretical model (W1BD) calculations. Both MP2 and DFT predict a single conformer with C2v symmetry for ortho-xylene, and two conformers each for meta- and para-xylene, depending on the preferred orientations of the methyl groups. For meta-xylene the two conformers have Cs and C2 symmetry, and for para-xylene these conformers have C2v or C2h symmetry. Since the relative population of the two conformers is approximately 50% for both isomers and predicted frequencies and intensities are very similar for each conformer, an arbitrary choice to discuss the Cs conformer for meta-xylene and the C2v conformer for para-xylene is made. Integrated band intensities for all isomers are reported. Using the quantitative infrared data, the global warming potential values of each isomer are determined. Potential bands for atmospheric monitoring are also discussed.

Submersible optical sensors exposed to chemically dispersed crude oil: wave tank simulations for improved oil spill monitoring.

PubMed

Conmy, Robyn N; Coble, Paula G; Farr, James; Wood, A Michelle; Lee, Kenneth; Pegau, W Scott; Walsh, Ian D; Koch, Corey R; Abercrombie, Mary I; Miles, M Scott; Lewis, Marlon R; Ryan, Scott A; Robinson, Brian J; King, Thomas L; Kelble, Christopher R; Lacoste, Jordanna

2014-01-01

In situ fluorometers were deployed during the Deepwater Horizon (DWH) Gulf of Mexico oil spill to track the subsea oil plume. Uncertainties regarding instrument specifications and capabilities necessitated performance testing of sensors exposed to simulated, dispersed oil plumes. Dynamic ranges of the Chelsea Technologies Group AQUAtracka, Turner Designs Cyclops, Satlantic SUNA and WET Labs, Inc. ECO, exposed to fresh and artificially weathered crude oil, were determined. Sensors were standardized against known oil volumes and total petroleum hydrocarbons and benzene-toluene-ethylbenzene-xylene measurements-both collected during spills, providing oil estimates during wave tank dilution experiments. All sensors estimated oil concentrations down to 300 ppb oil, refuting previous reports. Sensor performance results assist interpretation of DWH oil spill data and formulating future protocols.

Aging Studies in Drosophila melanogaster

PubMed Central

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

2015-01-01

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

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION...,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The resins identified in paragraph (a) of... condensation of xylene-formaldehyde resin and 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins, to...

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

USDA-ARS?s Scientific Manuscript database

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

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

USDA-ARS?s Scientific Manuscript database

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

Current Recommendations for Managing Spotted Wing Drosophila (SWD), Drosophila suzukii, in PNW Strawberries

USDA-ARS?s Scientific Manuscript database

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

Determination of Benzene, Toluene, and Xylene by means of an ion mobility spectrometer device using photoionization

NASA Technical Reports Server (NTRS)

Leonhardt, J. W.; Bensch, H.; Berger, D.; Nolting, M.; Baumbach, J. I.

1995-01-01

The continuous monitoring of changes on the quality of ambient air is a field of advantage of ion mobility spectrometry. Benzene, Toluene, and Xylene are substances of special interest because of their toxicity. We present an optimized drift tube for ion mobility spectrometers, which uses photo-ionization tubes to produce the ions to be analyzed. The actual version of this drift tube has a length of 45 mm, an electric field strength established within the drift tube of about 180 V/cm and a shutter-opening-time of 400 mus. With the hydrogen tube used for ionisation a mean flux of 10(exp 12) photons/sq cm s was established for the experiments described. We discuss the results of investigations on Benzene, Toluene, and Xylene in normal used gasoline SUPER. The detection limits obtained with the ion mobility spectrometer developed in co-operation are in the range of 10 ppbv in this case. Normally, charge transfer from Benzene ions to Toluene takes place. Nevertheless the simultaneous determination in mixtures is possible by a data evaluation procedure developed for this case. The interferences found between Xylene and others are rather weak. The ion mobility spectra of different concentrations of gasoline SUPER are attached as an example for the resolution and the detection limit of the instrument developed. Resolution and sensitivity of the system are well demonstrated. A hand-held portable device produced just now is to be tested for special environmental analytical problems in some industrial and scientific laboratories in Germany.

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

Health Risk Assessment of Ambient Air Concentrations of Benzene, Toluene and Xylene (BTX) in Service Station Environments

PubMed Central

Edokpolo, Benjamin; Yu, Qiming Jimmy; Connell, Des

2014-01-01

A comprehensive evaluation of the adverse health effects of human exposures to BTX from service station emissions was carried out using BTX exposure data from the scientific literature. The data was grouped into different scenarios based on activity, location and occupation and plotted as Cumulative Probability Distributions (CPD) plots. Health risk was evaluated for each scenario using the Hazard Quotient (HQ) at 50% (CEXP50) and 95% (CEXP95) exposure levels. HQ50 and HQ95 > 1 were obtained with benzene in the scenario for service station attendants and mechanics repairing petrol dispensing pumps indicating a possible health risk. The risk was minimized for service stations using vapour recovery systems which greatly reduced the benzene exposure levels. HQ50 and HQ95 < 1 were obtained for all other scenarios with benzene suggesting minimal risk for most of the exposed population. However, HQ50 and HQ95 < 1 was also found with toluene and xylene for all scenarios, suggesting minimal health risk. The lifetime excess Cancer Risk (CR) and Overall Risk Probability for cancer on exposure to benzene was calculated for all Scenarios and this was higher amongst service station attendants than any other scenario. PMID:24945191

Ectoparasitic mites and their Drosophila hosts.

PubMed

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

2017-01-02

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

Metabolomic Studies in Drosophila.

PubMed

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.

The Drosophila vesicular monoamine transporter reduces pesticide-induced loss of dopaminergic neurons

PubMed Central

Lawal, Hakeem O.; Chang, Hui-Yun; Terrell, Ashley N.; Brooks, Elizabeth S.; Pulido, Dianne; Simon, Anne F.; Krantz, David E.

2010-01-01

Dopamine is cytotoxic and may play a role in the development of Parkinson’s disease. However, its interaction with environmental risk factors such as pesticides remains poorly understood. The vesicular monoamine transporter (VMAT) regulates intracellular dopamine content, and we have tested the neuroprotective effects of VMAT in vivo using the model organism Drosophila melanogaster. We find that Drosophila VMAT (dVMAT) mutants contain fewer dopaminergic neurons than wild type, consistent with a developmental effect, and that dopaminergic cell loss in the mutant is exacerbated by the pesticides rotenone and paraquat. Over-expression of DVMAT protein does not increase the survival of animals exposed to rotenone, but blocks the loss of dopaminergic neurons caused by this pesticide. These results are the first to demonstrate an interaction between a VMAT and pesticides in vivo, and provide an important model to investigate the mechanisms by which pesticides and cellular DA may interact to kill dopaminergic cells. PMID:20472063

Evaluation of Off-season Potential Breeding Sources for Spotted Wing Drosophila (Drosophila suzukii Matsumura) in Michigan.

PubMed

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.

Macrophages and cellular immunity in Drosophila melanogaster

PubMed Central

Gold, Katrina S.; Brückner, Katja

2016-01-01

The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. PMID:27117654

A Drosophila model for developmental nicotine exposure

PubMed Central

2017-01-01

Despite the known health risks of tobacco smoking, many people including pregnant women continue smoking. The effects of developmental nicotine exposure are known, but the underlying mechanisms are not well understood. Drosophila melanogaster is a model organism that can be used for uncovering genetic and molecular mechanisms for drugs of abuse. Here I show that Drosophila can be a model to elucidate the mechanisms for nicotine’s effects on a developing organism. Drosophila reared on nicotine food display developmental and behavioral effects similar to those in mammals including decreased survival and weight, increased developmental time, and decreased sensitivity to acute nicotine and ethanol. The Drosophila nicotinic acetylcholine receptor subunit alpha 7 (Dα7) mediates some of these effects. A novel role for Dα7 on ethanol sedation in Drosophila is also shown. Future research taking advantage of the genetic and molecular tools for Drosophila will allow additional discovery of the mechanisms behind the effects of nicotine during development. PMID:28498868

Volatile organic compounds from fungi isolated after hurricane katrina induce developmental defects and apoptosis in a Drosophila melanogaster model.

PubMed

Inamdar, Arati A; Bennett, Joan W

2015-05-01

In previous work, our laboratory developed a Drosophila model for studying the adverse effects of fungal volatile organic compounds (VOCs) emitted by growing cultures of molds. In this report, we have extended these studies and compared the toxic effects of fungal VOCs emitted from living cultures of four molds isolated after Hurricane Katrina from a flooded home in New Orleans. Strains of Aspergillus, Mucor, Penicillium, and Trichoderma were grown with wild-type larvae and the toxic effects of volatile products on the developmental stages of Drosophila larvae were evaluated. Furthermore, heterozygous mutants of Drosophila carrying the apoptotic genes, reaper and dronc, were used to assess the role of apoptosis in fungal VOCs mediated toxicity. Third-instar larvae of Drosophila carrying these apoptotic genes were exposed to fungal VOCs emitted from growing mold cultures for 10 days. The larval strains carrying apoptopic genes survived longer than the control wild type larvae; moreover, of those that survived, heterozygous reaper and dronc strains progressed to pupae and adult phases more rapidly, suggesting that fungal VOCs may induce apoptotic changes in flies. These data lend support to the use of Drosophila as an inexpensive and genetically versatile toxicological model to investigate the mechanistic basis for some of the human illnesses/symptoms associated with exposure to mold-contaminated indoor air, especially after hurricanes. © 2013 Wiley Periodicals, Inc.

An isotope dilution gas chromatography/mass spectrometry method for trace analysis of xylene and its metabolites in tissues following threshold limit value exposures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pyon, K.H.; Kracko, D.A.; Strunk, M.R.

1995-12-01

The existence of a nose-brain barrier that functions to protect the central nervous system (CNS) from inhaled toxicants has been postulated. Just as a blood-brain barrier protects the CNS from systemic toxicants, the nose-brain barrier may have similar characteristic functions. One component of interest is nasal xenobiotic metabolism and its effect on the transport of pollutants into the CNS at environmentally plausible levels of exposure. Previous results have shown that inhaled xylene are dimethyl phenol (DMP) and methyl benzyl alcohol (MBA), and the nonvolatile metabolites are toluic acid (TA) and methyl hippuric acid (MHA). The nonvolatile metabolites of xylene, alongmore » with a small quantity of volatiles, representing either parent xylene or volatile metabolites, are transported via the olfactory epithelium to the glomeruli within the olfactory bulbs of the brain. Further work will be done to establish the linearity for each analyte at the actual highest detection limit of the GC/MS.« less

Altered Gravity Induces Oxidative Stress in Drosophila Melanogaster

NASA Technical Reports Server (NTRS)

Bhattacharya, Sharmila; Hosamani, Ravikumar

2015-01-01

Altered gravity environments can induce increased oxidative stress in biological systems. Microarray data from our previous spaceflight experiment (FIT experiment on STS-121) indicated significant changes in the expression of oxidative stress genes in adult fruit flies after spaceflight. Currently, our lab is focused on elucidating the role of hypergravity-induced oxidative stress and its impact on the nervous system in Drosophila melanogaster. Biochemical, molecular, and genetic approaches were combined to study this effect on the ground. Adult flies (2-3 days old) exposed to acute hypergravity (3g, for 1 hour and 2 hours) showed significantly elevated levels of Reactive Oxygen Species (ROS) in fly brains compared to control samples. This data was supported by significant changes in mRNA expression of specific oxidative stress and antioxidant defense related genes. As anticipated, a stress-resistant mutant line, Indy302, was less vulnerable to hypergravity-induced oxidative stress compared to wild-type flies. Survival curves were generated to study the combined effect of hypergravity and pro-oxidant treatment. Interestingly, many of the oxidative stress changes that were measured in flies showed sex specific differences. Collectively, our data demonstrate that altered gravity significantly induces oxidative stress in Drosophila, and that one of the organs where this effect is evident is the brain.

Ectoparasitic mites and their Drosophila hosts

PubMed Central

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

2017-01-01

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

Hearing regulates Drosophila aggression.

PubMed

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

2017-02-21

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

Macrophages and cellular immunity in Drosophila melanogaster.

PubMed

Gold, Katrina S; Brückner, Katja

2015-12-01

The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. Copyright © 2016. Published by Elsevier Ltd.

Identification of a Novel Dioxygenase Involved in Metabolism of o-Xylene, Toluene, and Ethylbenzene by Rhodococcus sp. Strain DK17

PubMed Central

Kim, Dockyu; Chae, Jong-Chan; Zylstra, Gerben J.; Kim, Young-Soo; Kim, Seong-Ki; Nam, Myung Hee; Kim, Young Min; Kim, Eungbin

2004-01-01

Rhodococcus sp. strain DK17 is able to grow on o-xylene, benzene, toluene, and ethylbenzene. DK17 harbors at least two megaplasmids, and the genes encoding the initial steps in alkylbenzene metabolism are present on the 330-kb pDK2. The genes encoding alkylbenzene degradation were cloned in a cosmid clone and sequenced completely to reveal 35 open reading frames (ORFs). Among the ORFs, we identified two nearly exact copies (one base difference) of genes encoding large and small subunits of an iron sulfur protein terminal oxygenase that are 6 kb apart from each other. Immediately downstream of one copy of the dioxygenase genes (akbA1a and akbA2a) is a gene encoding a dioxygenase ferredoxin component (akbA3), and downstream of the other copy (akbA1b and akbA2b) are genes putatively encoding a meta-cleavage pathway. RT-PCR experiments show that the two copies of the dioxygenase genes are operonic with the downstream putative catabolic genes and that both operons are induced by o-xylene. When expressed in Escherichia coli, AkbA1a-AkbA2a-AkbA3 transformed o-xylene into 2,3- and 3,4-dimethylphenol. These were apparently derived from an unstable o-xylene cis-3,4-dihydrodiol, which readily dehydrates. This indicates a single point of attack of the dioxygenase on the aromatic ring. In contrast, attack of AkbA1a-AkbA2a-AkbA3 on ethylbenzene resulted in the formation of two different cis-dihydrodiols resulting from an oxidation at the 2,3 and the 3,4 positions on the aromatic ring, respectively. PMID:15574904

Resources for Biological Annotation of the Drosophila Genome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerald M. Rubin

2005-08-08

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

Gene expression variations during Drosophila metamorphosis in real and simulated gravity

NASA Astrophysics Data System (ADS)

Marco, R.; Leandro-García, L. J.; Benguría, A.; Herranz, R.; Zeballos, A.; Gassert, G.; van Loon, J. J.; Medina, F. J.

Establishing the extent and significance of the effects of the exposure to microgravity of complex living organisms is a critical piece of information if the long-term exploration of near-by planets involving human beings is going to take place in the Future As a first step in this direction we have started to look into the patterns of gene expression during Drosophila development in real and simulated microgravity using microarray analysis of mRNA isolated from samples exposed to different environmental conditions In these experiments we used Affymetrix chips version 1 0 containing probes for more than 14 000 genes almost the complete Drosophila genome 55 of which are tagged with some molecular or functional designation while 45 are still waiting to be identified in functional terms The real microgravity exposure was imposed on the samples during the crew exchanging Soyuz 8 Mission to the ISS in October 2003 when after 11 days in Microgravity the Spanish-born astronaut Pedro Duque returned in the Soyuz 7 capsule carrying the experiments prepared by our Team Due to the constraints in the current ISS experiments in these Missions we limited the stages explored in our experiment to the developmental processes occurring during Drosophila metamorphosis As the experimental conditions at the launch site Baikonour were fairly limited we prepared the experiment in Madrid Toulouse and transp o rted the samples at 15 C in a temperature controlled container to slow down the developmental process a

Developmental and transcriptional consequences of mutations in Drosophila TAF(II)60.

PubMed

Aoyagi, N; Wassarman, D A

2001-10-01

In vitro, the TAF(II)60 component of the TFIID complex contributes to RNA polymerase II transcription initiation by serving as a coactivator that interacts with specific activator proteins and possibly as a promoter selectivity factor that interacts with the downstream promoter element. In vivo roles for TAF(II)60 in metazoan transcription are not as clear. Here we have investigated the developmental and transcriptional requirements for TAF(II)60 by analyzing four independent Drosophila melanogaster TAF(II)60 mutants. Loss-of-function mutations in Drosophila TAF(II)60 result in lethality, indicating that TAF(II)60 provides a nonredundant function in vivo. Molecular analysis of TAF(II)60 alleles revealed that essential TAF(II)60 functions are provided by two evolutionarily conserved regions located in the N-terminal half of the protein. TAF(II)60 is required at all stages of Drosophila development, in both germ cells and somatic cells. Expression of TAF(II)60 from a transgene rescued the lethality of TAF(II)60 mutants and exposed requirements for TAF(II)60 during imaginal development, spermatogenesis, and oogenesis. Phenotypes of rescued TAF(II)60 mutant flies implicate TAF(II)60 in transcriptional mechanisms that regulate cell growth and cell fate specification and suggest that TAF(II)60 is a limiting component of the machinery that regulates the transcription of dosage-sensitive genes. Finally, TAF(II)60 plays roles in developmental regulation of gene expression that are distinct from those of other TAF(II) proteins.

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

USDA-ARS?s Scientific Manuscript database

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 ...

Evaluating the impact of water supply strategies on p-xylene biodegradation performance in an organic media-based biofilter.

PubMed

Gallastegui, G; Muñoz, R; Barona, A; Ibarra-Berastegi, G; Rojo, N; Elías, A

2011-01-30

The influence of water irrigation on both the long-term and short-term performance of p-xylene biodegradation under several organic loading scenarios was investigated using an organic packing material composed of pelletised sawdust and pig manure. Process operation in a modular biofilter, using no external water supply other than the moisture from the saturated inlet air stream, showed poor p-xylene abatement efficiencies (≈33 ± 7%), while sustained irrigation every 25 days rendered a high removal efficiency (RE) for a critical loading rate of 120 g m(-3)h(-1). Periodic profiles of removal efficiency, temperature and moisture content were recorded throughout the biofilter column subsequent to each biofilter irrigation. Hence, higher p-xylene biodegradation rates were always initially recorded in the upper module, which resulted in a subsequent increase in temperature and a decrease in moisture content. This decrease in the moisture content in the upper module resulted in a higher removal rate in the middle module, while the moisture level in the lower module steadily increased as a result of water condensation. Based on these results, mass balance calculations performed using measured bed temperatures and relatively humidity values were successfully used to account for water balances in the biofilter over time. Finally, the absence of bed compaction after 550 days of continuous operation confirmed the suitability of this organic material for biofiltration processes. Copyright © 2010 Elsevier B.V. All rights reserved.

Cytochrome P450-Dependent Metabolism of Caffeine in Drosophila melanogaster

PubMed Central

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

Functional Analysis of Human NF1 in Drosophila

DTIC Science & Technology

2008-12-01

also have learning problem. Such learning phenotypes have been recapitulated in animal models, including in mouse and Drosophila mutants. This proposal...by examining the phenotypes of mutated human genes expressed in Drosophila NF1 null mutants. We also propose that Gsα/NF1 activated AC pathway...in both Drosophila and mouse NF1 models. Our previous work has shown that defective cAMP signaling leads to the learning phenotype in Drosophila Nf1

Hearing regulates Drosophila aggression

PubMed Central

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

2017-01-01

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. PMID:28115690

Effects of high-LET particles /A-40/ on the brain of Drosophila melanogaster

NASA Technical Reports Server (NTRS)

Miquel, J.; Herman, M. M.; Benton, E. V.; Welch, G.

1976-01-01

To investigate the effects of galactic heavy particles on nervous tissue, Drosophila melanogaster flies were exposed to A-40 from the Super-HILAC accelerator at the Lawrence Berkeley Laboratory. The energy of the particles reaching the Drosophila neurons was 4.8 MeV/nucleon, and the fluence ranged from 60,000 to 80 million particles/sq cm. Thirty-five days after irradiation at the higher fluences, extensive tissue fragmentation and cysts were found. At fluences as low as one hit/two cell bodies (about 5 million) and one hit/90 cell bodies (about 90,000 particles/sq cm or 21 rad average dose) swelling of neuronal cytoplasm and focally fragmented membranes were noted; at fluences ranging from one hit/six to one hit/135 cell bodies, there was frequently a marked increase in glial lamellae around nerve-cell processes, which often had degenerative features. These findings support the view that single hits by heavy particles may injure nervous tissue.

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

USDA-ARS?s Scientific Manuscript database

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

Drosophila as an unconventional substrate for microfabrication

NASA Astrophysics Data System (ADS)

Shum, Angela J.; Parviz, Babak A.

2007-02-01

We present the application of Drosophila fruit flies as an unconventional substrate for microfabrication. Drosophila by itself represents a complex system capable of many functions not attainable with current microfabrication technology. By using Drosophila as a substrate, we are able to capitalize on these natural functions while incorporating additional functionality into a superior hybrid system. In the following, development of microfabrication processes for Drosophila substrates is discussed. In particular, results of a study on Drosophila tolerance to vacuum pressure during multiple stages of development are given. A remarkable finding that adult Drosophila may withstand up to 3 hours of exposure to vacuum with measurable survival is noted. This finding opens a number of new opportunities for performing fabrication processes, similar to the ones performed on a silicon wafer, on a fruit fly as a live substrate. As a model microfabrication process, it is shown how a collection of Drosophila can be made to self-assemble into an array of microfabricated recesses on a silicon wafer and how a shadow mask can be used to thermally evaporate 100 nm of indium on flies. The procedure resulted in the production of a number of live flies with a pre-designed metal micropattern on their wings. This demonstration of vacuum microfabrication on a live organism provides the first step towards the development of a hybrid biological/solid-state manufacturing process for complex microsystems.

Dopamine and Mushroom Bodies in Drosophila: Experience-Dependent and -Independent Aspects of Sexual Behavior

PubMed Central

Neckameyer, Wendi S.

1998-01-01

Depletion of dopamine in Drosophila melanogaster adult males, accomplished through systemic introduction of the tyrosine hydroxylase inhibitor 3-iodo-tyrosine, severely impaired the ability of these flies to modify their courtship responses to immature males. Mature males, when first exposed to immature males, will perform courtship rituals; the intensity and duration of this behavior rapidly diminshes with time. Dopamine is also required for normal female sexual receptivity; dopamine-depleted females show increased latency to copulation. One kilobase of 5′ upstream information from the Drosophila tyrosine hydroxylase (DTH) gene, when fused to the Escherichia coli β-galactosidase reporter and transduced into the genome of Drosophila melanogaster, is capable of directing expression of the reporter gene in the mushroom bodies, which are believed to mediate learning acquisition and memory retention in flies. Ablation of mushroom bodies by treatment of newly hatched larva with hydroxyurea resulted in the inability of treated mature adult males to cease courtship when placed with untreated immature males. However, functional mushroom bodies were not required for the dopaminergic modulation of an innate behavior, female sexual receptivity. These data suggest that dopamine acts as a signaling molecule within the mushroom bodies to mediate a simple form of learning. PMID:10454380

Effect of microwave exposure on the ovarian development of Drosophila melanogaster.

PubMed

Panagopoulos, Dimitris J

2012-06-01

In the present experiments the effect of GSM radiation on ovarian development of virgin Drosophila melanogaster female insects was studied. Newly emerged adult female flies were collected and divided into separate identical groups. After the a lapse of certain number of hours-different for each group-the insects (exposed and sham-exposed) were dissected and their intact ovaries were collected and photographed under an optical microscope with the same magnification. The size of the ovaries was compared between exposed and sham-exposed virgin female insects, during the time needed for the completion of oogenesis and maturation of the first eggs in the ovarioles. Immediately after the intact ovaries were photographed, they were further dissected into individual ovarioles and treated for TUNEL and acridine-orange assays to determine the degree of DNA damage in the egg chamber cells. The study showed that the ovarian size of the exposed insects is significantly smaller than that of the corresponding sham-exposed insects, due to destruction of egg chambers by the GSM radiation, after DNA damage and consequent cell death induction in the egg chamber cells of the virgin females as shown in previous experiments on inseminated females. The difference in ovarian size between sham-exposed and exposed virgin female flies becomes most evident 39-45 h after eclosion when the first eggs within the ovaries are at the late vitellogenic and post-vitellogenic stages (mid-late oogenesis). More than 45 h after eclosion, the difference in ovarian size decreases, as the first mature eggs of the sham-exposed insects are leaving the ovaries and are laid.

Removal of traces of toluene and p-xylene in indoor air using biofiltration and a hybrid system (biofiltration + adsorption).

PubMed

Luengas, Angela Tatiana; Hort, Cécile; Platel, Vincent; Elias, Ana; Barona, Astrid; Moynault, Laurent

2017-04-01

Biofiltration technology and the hybrid system combining biofiltration and adsorption (onto activated carbon) were compared as possible methods to toluene and p-xylene at parts per million concentration levels (2-45 and 1-33 ppb, respectively). An organic material was used as packing material for the biofiltration process. Even at low empty bed residence times (EBRTs) and concentrations, toluene removal efficiency reached 100% and p-xylene showed an increasing trend on their removal efficiency over the time using biofiltration. The assessment of by-products and particle generation by the biofilter and the hybrid system were taken into account. Acetone and acetic acid were identified as by-products of the biofilter. Particle emissions in the range of 0.03 to 10 μm were recorded for both systems.

Metabolome analysis of Drosophila melanogaster during embryogenesis.

PubMed

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.

Metabolome Analysis of Drosophila melanogaster during Embryogenesis

PubMed Central

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. PMID:25121768

Heritable Endosymbionts of Drosophila

PubMed Central

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

2006-01-01

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

Integrated Gas Sensing System of SWCNT and Cellulose Polymer Concentrator for Benzene, Toluene, and Xylenes

PubMed Central

Im, Jisun; Sterner, Elizabeth S.; Swager, Timothy M.

2016-01-01

An integrated cellulose polymer concentrator/single-walled carbon nanotube (SWCNT) sensing system is demonstrated to detect benzene, toluene, and xylenes (BTX) vapors. The sensing system consists of functionalized cellulose as a selective concentrator disposed directly on top of a conductive SWCNT sensing layer. Functionalized cellulose concentrator (top layer) selectively adsorbs the target analyte and delivers the concentrated analyte as near as possible to the SWCNT sensing layer (bottom layer), which enables the simultaneous concentrating and sensing within a few seconds. The selectivity can be achieved by functionalizing cellulose acetate with a pentafluorophenylacetyl selector that interacts strongly with the target BTX analytes. A new design of the integrated cellulose concentrator/SWCNT sensing system allows high sensitivity with limits of detection for benzene, toluene, and m-xylene vapors of 55 ppm, 19 ppm, and 14 ppm, respectively, selectivity, and fast responses (<10 s to reach equilibrium), exhibiting the potential ability for on-site, real-time sensing applications. The sensing mechanism involves the selective adsorption of analytes in the concentrator film, which in turn mediates changes in the electronic potentials at the polymer-SWCNT interface and potentially changes in the tunneling barriers between nanotubes. PMID:26848660

The drosomycin multigene family: three-disulfide variants from Drosophila takahashii possess antibacterial activity

PubMed Central

Gao, Bin; Zhu, Shunyi

2016-01-01

Drosomycin (DRS) is a strictly antifungal peptide in Drosophila melanogaster, which contains four disulfide bridges (DBs) with three buried in molecular interior and one exposed on molecular surface to tie the amino- and carboxyl-termini of the molecule together (called wrapper disulfide bridge, WDB). Based on computational analysis of genomes of Drosophila species belonging to the Oriental lineage, we identified a new multigene family of DRS in Drosphila takahashii that includes a total of 11 DRS-encoding genes (termed DtDRS-1 to DtDRS-11) and a pseudogene. Phylogenetic tree and synteny analyses reveal orthologous relationship between DtDRSs and DRSs, indicating that orthologous genes of DRS-1, DRS-2, DRS-3 and DRS-6 have undergone duplication in D. takahashii and three amplifications (DtDRS-9 to DtDRS-11) of DRS-3 have lost WDB. Among the 11 genes, five are transcriptionally active in adult fruitflies. The ortholog of DRS (DtDRS-1) shows high structural and functional similarity to DRS while two WDB-deficient members display antibacterial activity accompanying complete loss or remarkable reduction of antifungal activity. To the best of our knowledge, this is the first report on the presence of three-disulfide antibacterial DRSs in a specific Drosophila species, suggesting a potential role of DB loss in neofunctionalization of a protein via structural adjustment. PMID:27562645

New record for the invasive Spotted Wing Drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Anillaco, Argentina

USDA-ARS?s Scientific Manuscript database

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...

Cryptochrome Mediates Light-Dependent Magnetosensitivity of Drosophila's Circadian Clock

PubMed Central

Yoshii, Taishi; Ahmad, Margaret; Helfrich-Förster, Charlotte

2009-01-01

Since 1960, magnetic fields have been discussed as Zeitgebers for circadian clocks, but the mechanism by which clocks perceive and process magnetic information has remained unknown. Recently, the radical-pair model involving light-activated photoreceptors as magnetic field sensors has gained considerable support, and the blue-light photoreceptor cryptochrome (CRY) has been proposed as a suitable molecule to mediate such magnetosensitivity. Since CRY is expressed in the circadian clock neurons and acts as a critical photoreceptor of Drosophila's clock, we aimed to test the role of CRY in magnetosensitivity of the circadian clock. In response to light, CRY causes slowing of the clock, ultimately leading to arrhythmic behavior. We expected that in the presence of applied magnetic fields, the impact of CRY on clock rhythmicity should be altered. Furthermore, according to the radical-pair hypothesis this response should be dependent on wavelength and on the field strength applied. We tested the effect of applied static magnetic fields on the circadian clock and found that flies exposed to these fields indeed showed enhanced slowing of clock rhythms. This effect was maximal at 300 μT, and reduced at both higher and lower field strengths. Clock response to magnetic fields was present in blue light, but absent under red-light illumination, which does not activate CRY. Furthermore, cryb and cryOUT mutants did not show any response, and flies overexpressing CRY in the clock neurons exhibited an enhanced response to the field. We conclude that Drosophila's circadian clock is sensitive to magnetic fields and that this sensitivity depends on light activation of CRY and on the applied field strength, consistent with the radical pair mechanism. CRY is widespread throughout biological systems and has been suggested as receptor for magnetic compass orientation in migratory birds. The present data establish the circadian clock of Drosophila as a model system for CRY

Torsional, Vibrational and Vibration-Torsional Levels in the S_{1} and Ground Cationic D_{0}^{+} States of Para-Xylene

NASA Astrophysics Data System (ADS)

Gardner, Adrian M.; Tuttle, William Duncan; Groner, Peter; Wright, Timothy G.

2017-06-01

Insight gained from examining the "pure" torsional, vibrational and vibration-torsional (vibtor) levels of the single rotor molecules: toluene (methylbenzene) and para-fluorotoluene (pFT), is applied to the double rotor para-xylene (p-dimethylbenzene) molecule . Resonance-enhanced multiphoton ionization (REMPI) spectroscopy and zero-kinetic-energy (ZEKE) spectroscopy are employed in order to investigate the S_{1} and ground cationic states of para-xylene. Observed transitions are assigned in the full molecular symmetry group (G_{72}) for the first time. J. R. Gascooke, E. A. Virgo, and W. D. Lawrance, J. Chem. Phys., 143, 044313 (2015). A. M. Gardner, W. D. Tuttle, L. Whalley, A. Claydon, J. H. Carter and T. G. Wright, J. Chem. Phys., 145, 124307 (2016). A. M. Gardner, W. D. Tuttle, P. Groner and T. G. Wright, J. Chem. Phys., (2017, in press).

Interspecies Interactions Determine the Impact of the Gut Microbiota on Nutrient Allocation in Drosophila melanogaster

PubMed Central

Douglas, Angela E.

2014-01-01

The animal gut is perpetually exposed to microorganisms, and this microbiota affects development, nutrient allocation, and immune homeostasis. A major challenge is to understand the contribution of individual microbial species and interactions among species in shaping these microbe-dependent traits. Using the Drosophila melanogaster gut microbiota, we tested whether microbe-dependent performance and nutritional traits of Drosophila are functionally modular, i.e., whether the impact of each microbial taxon on host traits is independent of the presence of other microbial taxa. Gnotobiotic flies were constructed with one or a set of five of the Acetobacter and Lactobacillus species which dominate the gut microbiota of conventional flies (Drosophila with untreated microbiota). Axenic (microbiota-free) flies exhibited prolonged development time and elevated glucose and triglyceride contents. The low glucose content of conventional flies was recapitulated in gnotobiotic Drosophila flies colonized with any of the 5 bacterial taxa tested. In contrast, the development rates and triglyceride levels in monocolonized flies varied depending on the taxon present: Acetobacter species supported the largest reductions, while most Lactobacillus species had no effect. Only flies with both Acetobacter and Lactobacillus had triglyceride contents restored to the level in conventional flies. This could be attributed to two processes: Lactobacillus-mediated promotion of Acetobacter abundance in the fly and a significant negative correlation between fly triglyceride content and Acetobacter abundance. We conclude that the microbial basis of host traits varies in both specificity and modularity; microbe-mediated reduction in glucose is relatively nonspecific and modular, while triglyceride content is influenced by interactions among microbes. PMID:24242251

Gene expression profiles of Drosophila melanogaster exposed to an insecticidal extract of Piper nigrum.

PubMed

Jensen, Helen R; Scott, Ian M; Sims, Steve; Trudeau, Vance L; Arnason, John Thor

2006-02-22

Black pepper, Piper nigrum L. (Piperaceae), has insecticidal properties and could potentially be utilized as an alternative to synthetic insecticides. Piperine extracted from P. nigrum has a biphasic effect upon cytochrome P450 monooxygenase activity with an initial suppression followed by induction. In this study, an ethyl acetate extract of P. nigrum seeds was tested for insecticidal activity toward adult Musca domestica and Drosophila melanogaster. The effect of this same P. nigrum extract upon differential gene expression in D. melanogaster was investigated using cDNA microarray analysis of 7380 genes. Treatment of D. melanogaster with P. nigrum extract led to a greater than 2-fold upregulation of transcription of the cytochrome P450 phase I metabolism genes Cyp 6a8, Cyp 9b2, and Cyp 12d1 as well as the glutathione-S-transferase phase II metabolism gene Gst-S1. These data suggests a complex effect of P. nigrum upon toxin metabolism.

Phylogeny of the Genus Drosophila

PubMed Central

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

Thermochemistry of C60 fullerene solutions in benzene, toluene, o-xylene, and o-dichlorobenzene at 298.15 K

NASA Astrophysics Data System (ADS)

Akhapkina, T. E.; Krusheva, M. A.; Solov'ev, S. N.; Firer, A. A.

2017-02-01

The enthalpies of dissolution of C60 in benzene, toluene, o-xylene and o-dichlorobenzene are measured in a sealed high-sensitivity calorimeter at 298.15 K and at different concentrations of the solute. The standard enthalpies of dissolution of C60 in these solvents are determined.

Validation of Comet assay in Oregon-R and Wild type strains of Drosophila melanogaster exposed to a natural radioactive environment in Brazilian semiarid region.

PubMed

Verçosa, Cícero Jorge; Moraes Filho, Aroldo Vieira de; Castro, Ícaro Fillipe de Araújo; Santos, Robson Gomes Dos; Cunha, Kenya Silva; Silva, Daniela de Melo E; Garcia, Ana Cristina Lauer; Navoni, Julio Alejandro; Amaral, Viviane Souza do; Rohde, Claudia

2017-07-01

Natural radiation of geological origin is a common phenomenon in Brazil, a country where radioactive agents such as uranium may be often found. As an unstable atom, uranium undergoes radioactive decay with the generation of a series of decay by-products, including radon, which may be highly genotoxic and trigger several pathological processes, among which cancer. Because it is a gas, radon may move freely between cracks and gaps in the ground, seeping upwards into the buildings and in the environment. In this study, two Drosophila melanogaster Meigen (Diptera, Drosophilidae) strains called Oregon-R and Wild (collected in a non-radioactive environment) were exposed to atmospheric radiation in the Lajes Pintadas city, in the semiarid zone of northeastern Brazil. After six days of environmental exposure, the organisms presented genetic damage significantly higher than that of the negative control group. The genotoxic effects observed reinforce the findings of other studies carried out in the same region, which warn about the environmental risks related to natural radioactivity occurrence. The results also validate the use of the Comet assay in hemocytes of D. melanogaster as a sensitive test to detect genotoxicity caused by natural radiation, and the use of a recently collected D. melanogaster strain in the environmental of radon. Copyright © 2017. Published by Elsevier Inc.

Comparative toxic potential of market formulation of two organophosphate pesticides in transgenic Drosophila melanogaster (hsp70-lacZ).

PubMed

Gupta, S C; Siddique, H R; Saxena, D K; Chowdhuri, D Kar

2005-01-01

This study investigated the working hypothesis that two widely used organophosphate pesticides; Nuvan and Dimecron, exert toxic effects in Drosophila. Transgenic D. melanogaster (hsp70-lacZ) was used as a model for assaying stress gene expression and AchE activity as an endpoint for toxicity and also to evaluate whether stress gene expression is sufficient to protect against toxic insult of the chemicals and to prevent tissue damage. The study was extended to investigate the effect of the pesticides on the life cycle and reproduction of the organism. The study showed that Nuvan affected emergence of the exposed flies more drastically than Dimecron and the effect was lethal at the highest tested concentration (0.075 ppm). While Nuvan at 0.0075 and 0.015 ppm concentrations affected reproduction of the flies significantly, the effect of Dimecron was significant only at 0.015 and 0.075 ppm. Nuvan-exposed third-instar larvae exhibited a 1.2-fold to 1.5-fold greater hsp70 expression compared to Dimecron at concentrations ranging from 0.0075 to 0.075 ppm following 12 and 18 h exposure. While maximum expression of hsp70 was observed in Nuvan-exposed third-instar larval tissues following 18 h exposure at 0.075 ppm, Dimecron at the same dietary concentration induced a maximum expression of hsp70 following 24 h exposure. Further, concomitant with a significant induction of hsp70, significant inhibition of AchE was observed following chemical exposure and temperature shock. Concurrent with a significant decline in hsp70 expression in Nuvan-exposed larvae after 48 h at 0.075 ppm, tissue damage was evident. Dimecron-exposed larvae exhibited a plateau in hsp70 induction even after 48 h exposure and moderate tissue damage was observed in these larvae. The present study suggests that Nuvan is more cytotoxic than Dimecron in transgenic Drosophila melanogaster.

Iron Absorption in Drosophila melanogaster

PubMed Central

Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

2013-01-01

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

Drosophila immunity research on the move.

PubMed

Eleftherianos, Ioannis; Schneider, David

2011-01-01

Drosophila has been established as useful model for infectious diseases because it allows large numbers of whole animals to be studied and provides powerful genetic tools and conservation with signaling and pathogenesis mechanisms in vertebrates. During the past twenty years, significant progress has been made on the characterization of innate immune responses against various pathogenic organisms in flies (Fig. 1). In this year's Drosophila Research Conference, which was held in San Diego (March 30-April 3) and sponsored by the Genetics Society of America, the immunity and pathogenesis session comprised seven platform presentations and 34 posters that highlighted the latest advances in Drosophila infection and immunity field. The presented work covered a wide range of studies from immune signaling pathways and the molecular basis of humoral and cellular immune mechanisms to the role of endosymbionts in fly immune function and effects of immune priming. Here, we give an overview of the presented work and we explain how these findings will open new avenues in Drosophila immunity research.

Characterization of Autophagic Responses in Drosophila melanogaster.

PubMed

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.

Methylmercury Exposure Induces Sexual Dysfunction in Male and Female Drosophila Melanogaster.

PubMed

Chauhan, Ved; Srikumar, Syian; Aamer, Sarah; Pandareesh, Mirazkar D; Chauhan, Abha

2017-09-24

Mercury, an environmental health hazard, is a neurotoxic heavy metal. In this study, the effect of methylmercury (MeHg) exposure was analyzed on sexual behavior in Drosophila melanogaster (fruit fly), because neurons play a vital role in sexual functions. The virgin male and female flies were fed a diet mixed with different concentrations of MeHg (28.25, 56.5, 113, 226, and 339 µM) for four days, and the effect of MeHg on copulation of these flies was studied. While male and female control flies (no MeHg) and flies fed with lower concentrations of MeHg (28.25, 56.5 µM) copulated in a normal manner, male and female flies exposed to higher concentrations of MeHg (113, 226, and 339 µM) did not copulate. When male flies exposed to higher concentrations of MeHg were allowed to copulate with control female flies, only male flies fed with 113 µM MeHg were able to copulate. On the other hand, when female flies exposed to higher concentrations of MeHg were allowed to copulate with control male flies, none of the flies could copulate. After introduction of male and female flies in the copulation chamber, duration of wing flapping by male flies decreased in a MeHg-concentration-dependent manner from 101 ± 24 seconds (control) to 100.7 ± 18, 96 ±12, 59 ± 44, 31 ± 15, and 3.7 ± 2.7 seconds at 28.25, 56.5, 113, 226, and 339 µM MeHg, respectively. On the other hand, grooming in male and female flies increased in a MeHg-concentration-dependent manner. These findings suggest that MeHg exposure causes sexual dysfunction in male and female Drosophila melanogaster . Further studies showed that MeHg exposure increased oxidative stress and decreased triglyceride levels in a concentration-dependent manner in both male and female flies, suggesting that MeHg-induced oxidative stress and decreased triglyceride levels may partly contribute to sexual dysfunction in fruit flies.

Insulin Stimulates Translocation of Human GLUT4 to the Membrane in Fat Bodies of Transgenic Drosophila melanogaster

PubMed Central

Crivat, Georgeta; Lizunov, Vladimir A.; Li, Caroline R.; Stenkula, Karin G.; Zimmerberg, Joshua; Cushman, Samuel W.; Pick, Leslie

2013-01-01

The fruit fly Drosophila melanogaster is an excellent model system for studies of genes controlling development and disease. However, its applicability to physiological systems is less clear because of metabolic differences between insects and mammals. Insulin signaling has been studied in mammals because of relevance to diabetes and other diseases but there are many parallels between mammalian and insect pathways. For example, deletion of Drosophila Insulin-Like Peptides resulted in ‘diabetic’ flies with elevated circulating sugar levels. Whether this situation reflects failure of sugar uptake into peripheral tissues as seen in mammals is unclear and depends upon whether flies harbor the machinery to mount mammalian-like insulin-dependent sugar uptake responses. Here we asked whether Drosophila fat cells are competent to respond to insulin with mammalian-like regulated trafficking of sugar transporters. Transgenic Drosophila expressing human glucose transporter-4 (GLUT4), the sugar transporter expressed primarily in insulin-responsive tissues, were generated. After expression in fat bodies, GLUT4 intracellular trafficking and localization were monitored by confocal and total internal reflection fluorescence microscopy (TIRFM). We found that fat body cells responded to insulin with increased GLUT4 trafficking and translocation to the plasma membrane. While the amplitude of these responses was relatively weak in animals reared on a standard diet, it was greatly enhanced in animals reared on sugar-restricted diets, suggesting that flies fed standard diets are insulin resistant. Our findings demonstrate that flies are competent to mobilize translocation of sugar transporters to the cell surface in response to insulin. They suggest that Drosophila fat cells are primed for a response to insulin and that these pathways are down-regulated when animals are exposed to constant, high levels of sugar. Finally, these studies are the first to use TIRFM to monitor insulin

G-rich, a Drosophila selenoprotein, is a Golgi-resident type III membrane protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Chang Lan; Shim, Myoung Sup; Chung, Jiyeol

2006-10-06

G-rich is a Drosophila melanogaster selenoprotein, which is a homologue of human and mouse SelK. Subcellular localization analysis using GFP-tagged G-rich showed that G-rich was localized in the Golgi apparatus. The fusion protein was co-localized with the Golgi marker proteins but not with an endoplasmic reticulum (ER) marker protein in Drosophila SL2 cells. Bioinformatic analysis of G-rich suggests that this protein is either type II or type III transmembrane protein. To determine the type of transmembrane protein experimentally, GFP-G-rich in which GFP was tagged at the N-terminus of G-rich, or G-rich-GFP in which GFP was tagged at the C-terminus ofmore » G-rich, were expressed in SL2 cells. The tagged proteins were then digested with trypsin, and analyzed by Western blot analysis. The results showed that the C-terminus of the G-rich protein was exposed to the cytoplasm indicating it is a type III microsomal membrane protein. G-rich is First selenoprotein identified in the Golgi apparatus.« less

Ultrafast gas chromatography method with direct injection for the quantitative determination of benzene, toluene, ethylbenzene, and xylenes in commercial gasoline.

PubMed

Miranda, Nahieh Toscano; Sequinel, Rodrigo; Hatanaka, Rafael Rodrigues; de Oliveira, José Eduardo; Flumignan, Danilo Luiz

2017-04-01

Benzene, toluene, ethylbenzene, and xylenes are some of the most hazardous constituents found in commercial gasoline samples; therefore, these components must be monitored to avoid toxicological problems. We propose a new routine method of ultrafast gas chromatography coupled to flame ionization detection for the direct determination of benzene, toluene, ethylbenzene, and xylenes in commercial gasoline. This method is based on external standard calibration to quantify each compound, including the validation step of the study of linearity, detection and quantification limits, precision, and accuracy. The time of analysis was less than 3.2 min, with quantitative statements regarding the separation and quantification of all compounds in commercial gasoline samples. Ultrafast gas chromatography is a promising alternative method to official analytical techniques. Government laboratories could consider using this method for quality control. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

USDA-ARS?s Scientific Manuscript database

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

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

PubMed

Cirulli, Elizabeth T; Noor, Mohamed A F

2007-01-01

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

Intestinal stem cells in the adult Drosophila midgut

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Huaqi, E-mail: Huaqi.Jiang@UTSouthwestern.edu; Edgar, Bruce A., E-mail: b.edgar@dkfz.de; Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109

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:more » 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.« less

Ancient Anxiety Pathways Influence Drosophila Defense Behaviors.

PubMed

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

2016-04-04

Anxiety helps us anticipate and assess potential danger in ambiguous situations [1-3]; however, the anxiety disorders are the most prevalent class of psychiatric illness [4-6]. Emotional states are shared between humans and other animals [7], as observed by behavioral manifestations [8], physiological responses [9], and gene conservation [10]. Anxiety research makes wide use of three rodent behavioral assays-elevated plus maze, open field, and light/dark box-that present a choice between sheltered and exposed regions [11]. Exposure avoidance in anxiety-related defense behaviors was confirmed to be a correlate of rodent anxiety by treatment with known anxiety-altering agents [12-14] and is now used to characterize anxiety systems. Modeling anxiety with a small neurogenetic animal would further aid the elucidation of its neuronal and molecular bases. Drosophila neurogenetics research has elucidated the mechanisms of fundamental behaviors and implicated genes that are often orthologous across species. In an enclosed arena, flies stay close to the walls during spontaneous locomotion [15, 16], a behavior proposed to be related to anxiety [17]. We tested this hypothesis with manipulations of the GABA receptor, serotonin signaling, and stress. The effects of these interventions were strikingly concordant with rodent anxiety, verifying that these behaviors report on an anxiety-like state. Application of this method was able to identify several new fly anxiety genes. The presence of conserved neurogenetic pathways in the insect brain identifies Drosophila as an attractive genetic model for the study of anxiety and anxiety-related disorders, complementing existing rodent systems. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Carbon nanopipette electrodes for dopamine detection in Drosophila.

PubMed

Rees, Hillary R; Anderson, Sean E; Privman, Eve; Bau, Haim H; Venton, B Jill

2015-04-07

Small, robust, sensitive electrodes are desired for in vivo neurotransmitter measurements. Carbon nanopipettes have been previously manufactured and used for single-cell drug delivery and electrophysiological measurements. Here, a modified fabrication procedure was developed to produce batches of solid carbon nanopipette electrodes (CNPEs) with ∼250 nm diameter tips, and controllable lengths of exposed carbon, ranging from 5 to 175 μm. The electrochemical properties of CNPEs were characterized with fast-scan cyclic voltammetry (FSCV) for the first time. CNPEs were used to detect the electroactive neurotransmitters dopamine, serotonin, and octopamine. CNPEs were significantly more sensitive for serotonin detection than traditional carbon-fiber microelectrodes (CFMEs). Similar to CFMEs, CNPEs have a linear response for dopamine concentrations ranging from 0.1 to 10 μM and a limit of detection of 25 ± 5 nM. Recordings with CNPEs were stable for over 3 h when the applied triangle waveform was scanned between -0.4 and +1.3 V vs Ag/AgCl/Cl(-) at 400 V/s. CNPEs were used to detect endogenous dopamine release in Drosophila larvae using optogenetics, which verified the utility of CNPEs for in vivo neuroscience studies. CNPEs are advantageous because they are 1 order of magnitude smaller in diameter than typical CFMEs and have a sharp, tunable geometry that facilitates penetration and implantation for localized measurements in distinct regions of small organisms, such as the Drosophila brain.

Carbon nanopipette electrodes for dopamine detection in Drosophila

PubMed Central

Rees, Hillary R.; Anderson, Sean E.; Privman, Eve; Bau, Haim H.; Venton, B. Jill

2015-01-01

Small, robust, sensitive electrodes are desired for in vivo neurotransmitter measurements. Carbon nanopipettes have been previously manufactured and used for single cell drug delivery and electrophysiological measurements. Here, a modified fabrication procedure was developed to produce batches of solid carbon nanopipette electrodes (CNPEs) with ~250 nm diameter tips, and controllable lengths of exposed carbon, ranging from 5 μm to 175 μm. The electrochemical properties of CNPEs were characterized with fast-scan cyclic voltammetry (FSCV) for the first time. CNPEs were used to detect the electroactive neurotransmitters dopamine, serotonin, and octopamine. CNPEs were significantly more sensitive for serotonin detection than traditional carbon fiber microelectrodes (CFMEs). Similar to CFMEs, CNPEs have a linear response for dopamine concentrations ranging from 0.1 to 10 μM and a LOD of 25 ± 5 nM. Recordings with CNPEs were stable for over 3 hours when the applied triangle waveform was scanned between −0.4 and 1.3 V vs. Ag/AgCl/Cl− at 400 V/s. CNPEs were used to detect endogenous dopamine release in Drosophila larvae using optogenetics, which verified the utility of CNPEs for in vivo neuroscience studies. CNPEs are advantageous because they are an order of magnitude smaller in diameter than typical CFMEs and have a sharp, tunable geometry that facilitates penetration and implantation for localized measurements in distinct regions of small organisms, such as the Drosophila brain. PMID:25711512

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

PubMed Central

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

2016-01-01

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

Drosophila Courtship Conditioning As a Measure of Learning and Memory.

PubMed

Koemans, Tom S; Oppitz, Cornelia; Donders, Rogier A T; van Bokhoven, Hans; Schenck, Annette; Keleman, Krystyna; Kramer, Jamie M

2017-06-05

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 resulting from mutations in genes associated with human cognitive disorders, such as intellectual disability (ID) and autism. This work describes a methodology for testing learning and memory using a classic paradigm in Drosophila known as courtship conditioning. Male flies court females using a distinct pattern of easily recognizable behaviors. Premated females are not receptive to mating and will reject the male's copulation attempts. In response to this rejection, male flies reduce their courtship behavior. This learned reduction in courtship behavior is measured over time, serving as an indicator of learning and memory. The basic numerical output of this assay is the courtship index (CI), which is defined as the percentage of time that a male spends courting during a 10 min interval. The learning index (LI) is the relative reduction of CI in flies that have been exposed to a premated female compared to naïve flies with no previous social encounters. For the statistical comparison of LIs between genotypes, a randomization test with bootstrapping is used. To illustrate how the assay can be used to address the role of a gene relating to learning and memory, the pan-neuronal knockdown of Dihydroxyacetone phosphate acyltransferase (Dhap-at) was characterized here. The human ortholog of Dhap-at, glyceronephosphate O-acyltransferase (GNPT), is involved in rhizomelic chondrodysplasia punctata type 2, an autosomal-recessive syndrome characterized by severe ID. Using the courtship conditioning assay, it was determined that Dhap-at is required for long-term memory, but not for short-term memory. This result serves as a basis for further investigation of the underlying molecular

The digestive tract of Drosophila melanogaster.

PubMed

Lemaitre, Bruno; Miguel-Aliaga, Irene

2013-01-01

The digestive tract plays a central role in the digestion and absorption of nutrients. Far from being a passive tube, it provides the first line of defense against pathogens and maintains energy homeostasis by exchanging neuronal and endocrine signals with other organs. Historically neglected, the gut of the fruit fly Drosophila melanogaster has recently come to the forefront of Drosophila research. Areas as diverse as stem cell biology, neurobiology, metabolism, and immunity are benefitting from the ability to study the genetics of development, growth regulation, and physiology in the same organ. In this review, we summarize our knowledge of the Drosophila digestive tract, with an emphasis on the adult midgut and its functional underpinnings.

Developmental nicotine exposure affects larval brain size and the adult dopaminergic system of Drosophila melanogaster.

PubMed

Morris, Melanie; Shaw, Ariel; Lambert, Madison; Perry, Haley Halperin; Lowenstein, Eve; Valenzuela, David; Velazquez-Ulloa, Norma Andrea

2018-06-14

Pregnant women may be exposed to nicotine if they smoke or use tobacco products, nicotine replacement therapy, or via e-cigarettes. Prenatal nicotine exposure has been shown to have deleterious effects on the nervous system in mammals including changes in brain size and in the dopaminergic system. The genetic and molecular mechanisms for these changes are not well understood. A Drosophila melanogaster model for these effects of nicotine exposure could contribute to faster identification of genes and molecular pathways underlying these effects. The purpose of this study was to determine if developmental nicotine exposure affects the nervous system of Drosophila melanogaster, focusing on changes to brain size and the dopaminergic system at two developmental stages. We reared flies on control or nicotine food from egg to 3rd instar larvae or from egg to adult and determined effectiveness of the nicotine treatment. We used immunohistochemistry to visualize the whole brain and dopaminergic neurons, using tyrosine hydroxylase as the marker. We measured brain area, tyrosine hydroxylase fluorescence, and counted the number of dopaminergic neurons in brain clusters. We detected an increase in larval brain hemisphere area, a decrease in tyrosine hydroxylase fluorescence in adult central brains, and a decrease in the number of neurons in the PPM3 adult dopaminergic cluster. We tested involvement of Dα7, one of the nicotinic acetylcholine receptor subunits, and found it was involved in eclosion, as previously described, but not involved in brain size. We conclude that developmental nicotine exposure in Drosophila melanogaster affects brain size and the dopaminergic system. Prenatal nicotine exposure in mammals has also been shown to have effects on brain size and in the dopaminergic system. This study further establishes Drosophila melanogaster as model organism to study the effects of developmental nicotine exposure. The genetic and molecular tools available for Drosophila

DETERMINATION OF A BOUND MUSK XYLENE ...

EPA Pesticide Factsheets

Musk xylene (MX) is widely used as a fragrance ingredient in commercial toiletries. Identification and quantification of a bound 4-amino-MX (AMX) metabolite was carried out by gas chromatography-mass spectrometry (GC/MS), with selected ion monitoring (SIM). Detection of AMX occurred after the cysteine adducts in carp hemoglobin, derived from the nitroso metabolite, were released by alkaline hydrolysis. The released AMX metabolite was extracted into n-hexane. The extract was preconcentrated by evaporation, and analyzed by GC-SIM-MS. The concentration of AMX metabolite was found to range from 6.0 to 30.6 ng/g in the carp Hb, collected from the Las Vegas Wash and Lake Mead, Nevada areas. The presence of an AMX metabolite in the carp Hb was confirmed when similar mass spectral features and the same retention time of the AMX metabolite were obtained for both standard AMX and carp Hb extract solutions. In the non-hydrolyzed and reagent blank extracts, the AMX metabolite was not detected. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers,

Cholinergic synaptic transmissions were altered after single sevoflurane exposure in Drosophila pupa.

PubMed

Chen, Rongfa; Zhang, Tao; Kuang, Liting; Chen, Zhen; Ran, Dongzhi; Niu, Yang; Xu, Kangqing; Gu, Huaiyu

2015-01-01

. Sevoflurane, one of the most used general anesthetics, is widely used in clinical practice all over the world. Previous studies indicated that sevoflurane could induce neuron apoptosis and neural deficit causing query in the safety of anesthesia using sevoflurane. The present study was designed to investigate the effects of sevoflurane on electrophysiology in Drosophila pupa whose excitatory neurotransmitter is acetylcholine early after sevoflurane exposure using whole brain recording technique. Wide types of Drosophila (canton-s flies) were allocated to control and sevoflurane groups randomly. Sevoflurane groups (1% sevoflurane; 2% sevoflurane; 3% sevoflurane) were exposed to sevoflurane and the exposure lasted 5 hours, respectively. All flies were subjected to electrophysiology experiment using patch clamp 24 hours after exposure. The results showed that, 24 hours after sevoflurane exposure, frequency but not the amplitude of miniature excitatory postsynaptic currents (mEPSCs) was significantly reduced (P < 0.05). Furthermore, we explored the underlying mechanism and found that calcium currents density, which partially regulated the frequency of mEPSCs, was significantly reduced after sevoflurane exposure (P < 0.05). All these suggested that sevoflurane could alter the mEPSCs that are related to synaptic plasticity partially through modulating calcium channel early after sevoflurane exposure.

Gut-associated microbes of Drosophila melanogaster

PubMed Central

Broderick, Nichole; Lemaitre, Bruno

2012-01-01

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

Efficacy of xylene and passive ultrasonic irrigation on remaining root filling material during retreatment of anatomically complex teeth.

PubMed

Cavenago, B C; Ordinola-Zapata, R; Duarte, M A H; del Carpio-Perochena, A E; Villas-Bôas, M H; Marciano, M A; Bramante, C M; Moraes, I G

2014-11-01

To evaluate the volume of remaining filling material in the mesial root canals of mandibular molars after root canal retreatment with different procedures performed sequentially. The mesial root canals of 12 human first mandibular molars were instrumented using the BioRace system until a size 25, .06 taper instrument. The mesial roots were filled with gutta-percha and AH-Plus using a vertical compaction technique. The specimens were scanned using microcomputed tomography with a voxel size of 16.8 μm before and after the retreatment procedures. To remove the filling material, the root canals were enlarged until the size 40, .04 taper instrument. The second step was to irrigate the root canals with xylene in the attempt to clean the root canals with paper points. In the third step, the passive ultrasonic irrigation technique (PUI) was performed using 2.5% sodium hypochlorite. The initial and residual filling material volume (mm(3) ) after each step was evaluated from the 0.5 to 6.5 mm level. The obtained data were expressed in terms of percentage of residual filling material. Statistical analysis was performed using the Friedman test (P < 0.05). All specimens had residual filling materials after all retreatment procedures. Passive ultrasonic irrigation enhanced the elimination of residual filling material in comparison with the mechanical stage at the 0.5-2.5 mm and 4.5-6.5 mm levels (P < 0.05). No significant difference was found between xylene and PUI methods. Filling materials were not completely removed by any of the retreatment procedures. The use of xylene and PUI after mechanical instrumentation enhanced removal of materials during endodontic retreatment of anatomically complex teeth. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A novel, tissue-specific, Drosophila homeobox gene.

PubMed

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

1988-07-01

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

Drosophila cellular immunity: a story of migration and adhesion.

PubMed

Fauvarque, Marie-Odile; Williams, Michael J

2011-05-01

Research during the past 15 years has led to significant breakthroughs, providing evidence of a high degree of similarity between insect and mammalian innate immune responses, both humoural and cellular, and highlighting Drosophila melanogaster as a model system for studying the evolution of innate immunity. In a manner similar to cells of the mammalian monocyte and macrophage lineage, Drosophila immunosurveillance cells (haemocytes) have a number of roles. For example, they respond to wound signals, are involved in wound healing and contribute to the coagulation response. Moreover, they participate in the phagocytosis and encapsulation of invading pathogens, are involved in the removal of apoptotic bodies and produce components of the extracellular matrix. There are several reasons for using the Drosophila cellular immune response as a model to understand cell signalling during adhesion and migration in vivo: many genes involved in the regulation of Drosophila haematopoiesis and cellular immunity have been maintained across taxonomic groups ranging from flies to humans, many aspects of Drosophila and mammalian innate immunity seem to be conserved, and Drosophila is a simplified and well-studied genetic model system. In the present Commentary, we will discuss what is known about cellular adhesion and migration in the Drosophila cellular immune response, during both embryonic and larval development, and where possible compare it with related mechanisms in vertebrates.

Physiological effects of heat stress on Hawaiian picture-wing Drosophila: genome-wide expression patterns and stress-related traits

PubMed Central

Uy, Karen L; LeDuc, R; Ganote, C; Price, Donald K

2015-01-01

Abstract Climate change is compounding the threats to the future of biodiversity, already impacted by habitat loss, invasive species and diseases. In the Hawaiian Islands, many of the endemic species have narrow habitat ranges that make them especially vulnerable to climate change. The Hawaiian Drosophila, a remarkably diverse group of species with 11 listed as federally endangered, are thought to be sensitive to temperature changes. To examine the species differences in sensitivity of Hawaiian picture-wing Drosophila to temperature changes, wild populations of Drosophila sproati, a relatively common species, and Drosophila silvestris, a rare species, were collected from two locations on Hawaii Island and bred in common laboratory conditions. Adult flies were exposed to hot and cold temperatures and compared with adult flies at control temperatures. Drosophila silvestris adults were less tolerant to heat stress than D. sproati for both survival and sperm mobility. In contrast, D. silvestris adults were more tolerant to cold stress than D. sproati for adult survival. The expression of 4950 Gene Ontology annotated gene transcripts was also analysed in high-temperature-treated and control males to identify candidate genes related to heat tolerance. There were more than twice as many transcripts differentially expressed after high temperature treatment for D. silvestris (246 transcripts) as for D. sproati (106 transcripts), with 13 Gene Ontology terms enriched between temperatures for D. silvestris and merely three in D. sproati. The combined results are consistent with D. sproati occurring more widely today as well as occurring at lower elevations than D. silvestris and with a genetically based temperature response, which is more severe in D. silvestris at high temperatures than that in D. sproati. These experiments demonstrate the potential for different capacities of species to adapt to future climate change conditions as well as providing an explanation for

Pickle Flavors Relish in Drosophila Immunity.

PubMed

Salminen, Tiina Susanna; Rämet, Mika

2016-09-14

Immune responses must be tightly controlled to avoid host damage. In Drosophila, two NF-κB signaling pathways, Toll and Imd, mediate host immune responses. In this issue of Cell Host & Microbe, Morris et al. (2016) introduce Pickle, a nuclear IκB that inhibits Drosophila immune signaling by modulating the NF-κB Relish. Copyright © 2016 Elsevier Inc. All rights reserved.

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

PubMed

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

2016-08-16

How the evolution of olfactory genes correlates with adaption to new ecological niches is still a debated topic. We explored this issue in Drosophila suzukii, an emerging model that reproduces on fresh fruit rather than in fermenting substrates like most other Drosophila We first annotated the repertoire of odorant receptors (ORs), odorant binding proteins (OBPs), and antennal ionotropic receptors (aIRs) in the genomes of two strains of D. suzukii and of its close relative Drosophila biarmipes We then analyzed these genes on the phylogeny of 14 Drosophila species: whereas ORs and OBPs are characterized by higher turnover rates in some lineages including D. suzukii, aIRs are conserved throughout the genus. Drosophila suzukii is further characterized by a non-random distribution of OR turnover on the gene phylogeny, consistent with a change in selective pressures. In D. suzukii, we found duplications and signs of positive selection in ORs with affinity for short-chain esters, and loss of function of ORs with affinity for volatiles produced during fermentation. These receptors-Or85a and Or22a-are characterized by divergent alleles in the European and American genomes, and we hypothesize that they may have been replaced by some of the duplicated ORs in corresponding neurons, a hypothesis reciprocally confirmed by electrophysiological recordings. Our study quantifies the evolution of olfactory genes in Drosophila and reveals an array of genomic events that can be associated with the ecological adaptations of D. suzukii. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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

ERIC Educational Resources Information Center

Venema, Dennis R.

2006-01-01

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

Drosophila and Beer: An Experimental Laboratory Exercise

ERIC Educational Resources Information Center

Kurvink, Karen

2004-01-01

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

Early Liver and Kidney Dysfunction Associated with Occupational Exposure to Sub-Threshold Limit Value Levels of Benzene, Toluene, and Xylenes in Unleaded Petrol

PubMed Central

Neghab, Masoud; Hosseinzadeh, Kiamars; Hassanzadeh, Jafar

2015-01-01

Background Unleaded petrol contains significant amounts of monocyclic aromatic hydrocarbons such as benzene, toluene, and xylenes (BTX). Toxic responses following occupational exposure to unleaded petrol have been evaluated only in limited studies. The main purpose of this study was to ascertain whether (or not) exposure to unleaded petrol, under normal working conditions, is associated with any hepatotoxic or nephrotoxic response. Methods This was a cross-sectional study in which 200 employees of Shiraz petrol stations with current exposure to unleaded petrol, as well as 200 unexposed employees, were investigated. Atmospheric concentrations of BTX were measured using standard methods. Additionally, urine and fasting blood samples were taken from individuals for urinalysis and routine biochemical tests of kidney and liver function. Results The geometric means of airborne concentrations of BTX were found to be 0.8 mg m−3, 1.4 mg m−3, and 2.8 mg m−3, respectively. Additionally, means of direct bilirubin, alanine aminotransferase, aspartate aminotransferase, blood urea and plasma creatinine were significantly higher in exposed individuals than in unexposed employees. Conversely, serum albumin, total protein, and serum concentrations of calcium and sodium were significantly lower in petrol station workers than in their unexposed counterparts. Conclusion The average exposure of petrol station workers to BTX did not exceed the current threshold limit values (TLVs) for these chemicals. However, evidence of subtle, subclinical and prepathologic early liver and kidney dysfunction was evident in exposed individuals. PMID:26929843

Virus recognition by Toll-7 activates antiviral autophagy in Drosophila.

PubMed

Nakamoto, Margaret; Moy, Ryan H; Xu, Jie; Bambina, Shelly; Yasunaga, Ari; Shelly, Spencer S; Gold, Beth; Cherry, Sara

2012-04-20

Innate immunity is highly conserved and relies on pattern recognition receptors (PRRs) such as Toll-like receptors (identified through their homology to Drosophila Toll) for pathogen recognition. Although Drosophila Toll is vital for immune recognition and defense, roles for the other eight Drosophila Tolls in immunity have remained elusive. Here we have shown that Toll-7 is a PRR both in vitro and in adult flies; loss of Toll-7 led to increased vesicular stomatitis virus (VSV) replication and mortality. Toll-7, along with additional uncharacterized Drosophila Tolls, was transcriptionally induced by VSV infection. Furthermore, Toll-7 interacted with VSV at the plasma membrane and induced antiviral autophagy independently of the canonical Toll signaling pathway. These data uncover an evolutionarily conserved role for a second Drosophila Toll receptor that links viral recognition to autophagy and defense and suggest that other Drosophila Tolls may restrict specific as yet untested pathogens, perhaps via noncanonical signaling pathways. Copyright © 2012 Elsevier Inc. All rights reserved.

Visual Place Learning in Drosophila melanogaster

PubMed Central

Ofstad, Tyler A.; Zuker, Charles S.; Reiser, Michael B.

2011-01-01

The ability of insects to learn and navigate to specific locations in the environment has fascinated naturalists for decades. While the impressive navigation abilities of ants, bees, wasps, and other insects clearly demonstrate that insects are capable of visual place learning1–4, little is known about the underlying neural circuits that mediate these behaviors. Drosophila melanogaster is a powerful model organism for dissecting the neural circuitry underlying complex behaviors, from sensory perception to learning and memory. Flies can identify and remember visual features such as size, color, and contour orientation5, 6. However, the extent to which they use vision to recall specific locations remains unclear. Here we describe a visual place-learning platform and demonstrate that Drosophila are capable of forming and retaining visual place memories to guide selective navigation. By targeted genetic silencing of small subsets of cells in the Drosophila brain we show that neurons in the ellipsoid body, but not in the mushroom bodies, are necessary for visual place learning. Together, these studies reveal distinct neuroanatomical substrates for spatial versus non-spatial learning, and substantiate Drosophila as a powerful model for the study of spatial memories. PMID:21654803

Discovery of trypanosomatid parasites in globally distributed Drosophila species.

PubMed

Chandler, James Angus; James, Pamela M

2013-01-01

Microbial parasites of animals include bacteria, viruses, and various unicellular eukaryotes. Because of the difficulty in studying these microorganisms in both humans and disease vectors, laboratory models are commonly used for experimental analysis of host-parasite interactions. Drosophila is one such model that has made significant contributions to our knowledge of bacterial, fungal, and viral infections. Despite this, less is known about other potential parasites associated with natural Drosophila populations. Here, we surveyed sixteen Drosophila populations comprising thirteen species from four continents and Hawaii and found that they are associated with an extensive diversity of trypanosomatids (Euglenozoa, Kinetoplastea). Phylogenetic analysis finds that Drosophila-associated trypanosomatids are closely related to taxa that are responsible for various types of leishmaniases and more distantly related to the taxa responsible for human African trypanosomiasis and Chagas disease. We suggest that Drosophila may provide a powerful system for studying the interactions between trypanosomatids and their hosts.

Modulation of sestrin confers protection to Cr(VI) induced neuronal cell death in Drosophila melanogaster.

PubMed

Singh, Pallavi; Chowdhuri, D Kar

2018-01-01

Increased oxidative stress is one of the major causes of hexavalent chromium [Cr(VI)], a heavy metal with diverse applications and environmental presence, induced neuronal adversities in exposed organism including Drosophila. Sestrin (sesn), an oxidative stress responsive gene, emerges as a novel player in the management of oxidative stress response. It is reported to be regulated by Target of rapamycin (TOR) and the former regulates autophagy and plays an important role in the prevention of neurodegeneration. Due to limited information regarding the role of sesn in chemical induced cellular adversities, it was hypothesized that modulation of sesn may improve the Cr(VI) induced neuronal adversities in Drosophila. Upon exposure of Cr(VI) (5.0-20.0 μg/ml) to D. melanogaster larvae (w 1118 ; background control), neuronal cell death was observed at 20.0 μg/ml of Cr(VI) concentration which was found to be reversed by targeted sesn overexpression (Elav-GAL4>UAS-sesn) in those cells of exposed organism by the induction of autophagy concomitant with decreased reactive oxygen species (ROS) level, p-Foxo-, p-JNK- and p-Akt-levels with decreased apoptosis. Conversely, after sesn knockdown (Elav-GAL4>UAS-sesn RNAi ) in neuronal cells, they become more vulnerable to oxidative stress and apoptosis. Furthermore, knockdown of sesn in neuronal cells of exposed organism resulted in decreased autophagy with increased TOR and p-S6k levels while overexpression of sesn led to their decreased levels suggestive of decreased anabolic and increased catabolic activity in neuronal cells shifting energy towards the augmentation of cellular repair. Taken together, the study suggests therapeutic implications of sesn against chemical induced neuronal adversities in an organism. Copyright © 2017 Elsevier Ltd. All rights reserved.

The fruit fly Drosophila melanogaster unfolds the secrets of innate immunity.

PubMed

Rämet, Mika

2012-09-01

In 2011, the Nobel Prize in Physiology and Medicine was rewarded, in part, for research on the Drosophila immune response. The research described the role of the Drosophila Toll receptor in antifungal resistance, and the subsequent characterization of Toll-like receptors in mammals reshaped our understanding of the immune system. This review summarizes the potential of the Drosophila model and describes the path that has lead Drosophila to become an important model to study immunity. Drosophila melanogaster has been one of the most fruitful models to study innate immunity. © 2012 The Author(s)/Acta Paediatrica © 2012 Foundation Acta Paediatrica.

IMPACT OF ETHANOL ON THE NATURAL ATTENUATION OF BENZENE, TOLUENE, AND O-XYLENE IN A NORMALLY SULFATE-REDUCING AQUIFER

EPA Science Inventory

Two side-by-side field experiments were conducted in a shallow sulfate-reducing aquifer at a former service station site at Vandenberg Air Force Base, CA. On one side, we injected site groundwater amended with 1-3 mg/L benzene, toluene, and o-xylene (B, T, and o-X). On the othe...

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

USDA-ARS?s Scientific Manuscript database

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...

Receptor Tyrosine Kinases in Drosophila Development

PubMed Central

Sopko, Richelle; Perrimon, Norbert

2013-01-01

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

Viruses and Antiviral Immunity in Drosophila

PubMed Central

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

Multiple capacitors for natural genetic variation in Drosophila melanogaster.

PubMed

Takahashi, Kazuo H

2013-03-01

Cryptic genetic variation (CGV) or a standing genetic variation that is not ordinarily expressed as a phenotype is released when the robustness of organisms is impaired under environmental or genetic perturbations. Evolutionary capacitors modulate the amount of genetic variation exposed to natural selection and hidden cryptically; they have a fundamental effect on the evolvability of traits on evolutionary timescales. In this study, I have demonstrated the effects of multiple genomic regions of Drosophila melanogaster on CGV in wing shape. I examined the effects of 61 genomic deficiencies on quantitative and qualitative natural genetic variation in the wing shape of D. melanogaster. I have identified 10 genomic deficiencies that do not encompass a known candidate evolutionary capacitor, Hsp90, exposing natural CGV differently depending on the location of the deficiencies in the genome. Furthermore, five genomic deficiencies uncovered qualitative CGV in wing morphology. These findings suggest that CGV in wing shape of wild-type D. melanogaster is regulated by multiple capacitors with divergent functions. Future analysis of genes encompassed by these genomic regions would help elucidate novel capacitor genes and better understand the general features of capacitors regarding natural genetic variation. © 2012 Blackwell Publishing Ltd.

Electron-transporting small molecule/ o-xylene hybrid additives to boost the performance of simplified inverted polymer solar cells

NASA Astrophysics Data System (ADS)

Qin, Dashan; Cao, Huan; Zhang, Jidong

2017-05-01

Electron-transporting small molecule bathophenanthroline (Bphen) together with o-xylene has been used as hybrid additives to improve the performance of simplified inverted polymer solar cells employing ITO alone as cathode and photoactive layer based on polymer [[2,6'-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,3-b] dithiophene] [3-fluoro-2[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

Simulation of SOA formation and composition from oxidation of toluene and m-xylene in chamber experiments

NASA Astrophysics Data System (ADS)

Xu, J.; Liu, Y.; Nakao, S.; Cocker, D.; Griffin, R. J.

2013-12-01

Aromatic hydrocarbons contribute an important fraction of anthropogenic reactive volatile organic compounds (VOCs) in the urban atmosphere. Photo-oxidation of aromatic hydrocarbons leads to secondary organic products that have decreased volatilities or increased solubilities and can form secondary organic aerosol (SOA). Despite the crucial role of aromatic-derived SOA in deteriorating air quality and harming human health, its formation mechanism is not well understood and model simulation of SOA formation still remains difficult. The dependence of aromatic SOA formation on nitrogen oxides (NOx) is not captured fully by most SOA formation models. Most models predict SOA formation under high NOx levels well but underestimate SOA formation under low NOx levels more representative of the ambient atmosphere. Thus, it is crucial to investigate the NOx-dependent chemistry in aromatic photo-oxidation systems and correspondingly update SOA formation models. In this study, NOx-dependent mechanisms of toluene and m-xylene SOA formation are updated using the gas-phase Caltech Atmospheric Chemistry Mechanism (CACM) coupled to a gas/aerosol partitioning model. The updated models were optimized by comparing to eighteen University of California, Riverside United States Environmental Protection Agency (EPA) chamber experiment runs under both high and low NOx conditions. Correction factors for vapor pressures imply uncharacterized aerosol-phase association chemistry. Simulated SOA speciation implies the importance of ring-opening products in governing SOA formation (up to 40%~60% for both aromatics). The newly developed model can predict strong decreases of m-xylene SOA yield with increasing NOx. Speciation distributions under varied NOx levels implies that the well-known competition between RO2 + HO2 and RO2 + NO (RO2 = peroxide bicyclic radical) may not be the only factor influencing SOA formation. The reaction of aromatic peroxy radicals with NO competing with its self

Thermochemical data and additivity group values for ten species of o-xylene low-temperature oxidation mechanism.

PubMed

Canneaux, Sébastien; Vandeputte, Romain; Hammaecher, Catherine; Louis, Florent; Ribaucour, Marc

2012-01-12

o-Xylene could be a good candidate to represent the family of aromatic hydrocarbons in a surrogate fuel. This study uses computational chemistry to calculate standard enthalpies of formation at 298 K, Δ(f)H°(298 K), standard entropies at 298 K, S°(298 K), and standard heat capacities C(p)°(T) over the temperature range 300 K to 1500 K for ten target species present in the low-temperature oxidation mechanism of o-xylene: o-xylene (1), 2-methylbenzyl radical (2), 2-methylbenzylperoxy radical (3), 2-methylbenzyl hydroperoxide (4), 2-(hydroperoxymethyl)benzyl radical (5), 2-(hydroperoxymethyl)benzaldehyde (6), 1-ethyl-2-methylbenzene (7), 2,3-dimethylphenol (8), 2-hydroxybenzaldehyde (9), and 3-hydroxybenzaldehyde (10). Δ(f)H°(298 K) values are weighted averages across the values calculated using five isodesmic reactions and five composite calculation methods: CBS-QB3, G3B3, G3MP2, G3, and G4. The uncertainty in Δ(f)H°(298 K) is also evaluated. S°(298 K) and C(p)°(T) values are calculated at B3LYP/6-311G(d,p) level of theory from molecular properties and statistical thermodynamics through evaluation of translational, rotational, vibrational, and electronic partition functions. S°(298 K) and C(p)°(300 K) values are evaluated using the rigid-rotor-harmonic-oscillator model. C(p)°(T) values at T ≥ 400 K are calculated by treating separately internal rotation contributions and translational, external rotational, vibrational, and electronic contributions. The thermochemical properties of six target species are used to develop six new additivity groups taking into account the interaction between two substituents in ortho (ORT/CH2OOH/ME, ORT/ET/ME, ORT/CHO/OH, ORT/CHO/CH2OOH) or meta (MET/CHO/OH) positions, and the interaction between three substituents (ME/ME/OH123) located one beside the other (positions numbered 1, 2, 3) for two- or three-substituted benzenic species. Two other additivity groups are also developed using the thermochemical properties of

Reconstruction of Exposure to m-Xylene from Human Biomonitoring Data Using PBPK Modelling, Bayesian Inference, and Markov Chain Monte Carlo Simulation

PubMed Central

McNally, Kevin; Cotton, Richard; Cocker, John; Jones, Kate; Bartels, Mike; Rick, David; Price, Paul; Loizou, George

2012-01-01

There are numerous biomonitoring programs, both recent and ongoing, to evaluate environmental exposure of humans to chemicals. Due to the lack of exposure and kinetic data, the correlation of biomarker levels with exposure concentrations leads to difficulty in utilizing biomonitoring data for biological guidance values. Exposure reconstruction or reverse dosimetry is the retrospective interpretation of external exposure consistent with biomonitoring data. We investigated the integration of physiologically based pharmacokinetic modelling, global sensitivity analysis, Bayesian inference, and Markov chain Monte Carlo simulation to obtain a population estimate of inhalation exposure to m-xylene. We used exhaled breath and venous blood m-xylene and urinary 3-methylhippuric acid measurements from a controlled human volunteer study in order to evaluate the ability of our computational framework to predict known inhalation exposures. We also investigated the importance of model structure and dimensionality with respect to its ability to reconstruct exposure. PMID:22719759

Viruses and antiviral immunity in Drosophila.

PubMed

Xu, Jie; Cherry, Sara

2014-01-01

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 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparative Genomics in Drosophila.

PubMed

Oti, Martin; Pane, Attilio; Sammeth, Michael

2018-01-01

Since the pioneering studies of Thomas Hunt Morgan and coworkers at the dawn of the twentieth century, Drosophila melanogaster and its sister species have tremendously contributed to unveil the rules underlying animal genetics, development, behavior, evolution, and human disease. Recent advances in DNA sequencing technologies launched Drosophila into the post-genomic era and paved the way for unprecedented comparative genomics investigations. The complete sequencing and systematic comparison of the genomes from 12 Drosophila species represents a milestone achievement in modern biology, which allowed a plethora of different studies ranging from the annotation of known and novel genomic features to the evolution of chromosomes and, ultimately, of entire genomes. Despite the efforts of countless laboratories worldwide, the vast amount of data that were produced over the past 15 years is far from being fully explored.In this chapter, we will review some of the bioinformatic approaches that were developed to interrogate the genomes of the 12 Drosophila species. Setting off from alignments of the entire genomic sequences, the degree of conservation can be separately evaluated for every region of the genome, providing already first hints about elements that are under purifying selection and therefore likely functional. Furthermore, the careful analysis of repeated sequences sheds light on the evolutionary dynamics of transposons, an enigmatic and fascinating class of mobile elements housed in the genomes of animals and plants. Comparative genomics also aids in the computational identification of the transcriptionally active part of the genome, first and foremost of protein-coding loci, but also of transcribed nevertheless apparently noncoding regions, which were once considered "junk" DNA. Eventually, the synergy between functional and comparative genomics also facilitates in silico and in vivo studies on cis-acting regulatory elements, like transcription factor binding

Chemical Mass Shifts in a Digital Linear Ion Trap as Analytical Identity of o-, m-, and p-Xylene.

PubMed

Sun, Lulu; Xue, Bing; Huang, Zhengxu; Cheng, Ping; Ma, Li; Ding, Li; Zhou, Zhen

2018-07-01

Chemical mass shifts between isomeric ions of o-, m-, and p-xylene were measured using a digital linear ion trap, and the directions and values of the shifts were found to be correlated to the collision cross sections of the isomers. Both forward and reverse scans were used and the chemical shifts for each pair of isomers in scans of opposite directions were in opposite signs. Using different voltage settings (namely the voltage dividing ratio-VDR) of the ion trap allows adding high order field components in the quadrupole field and results in larger chemical mass shifts. The differential chemical mass shift which combined the shifts from forward and reverse scans doubled the amount of chemical shift, e.g., 0.077 Th between o- and p-xylene, enough for identification of the type of isomer without using an additional ion mobility spectrometer. The feature of equal and opposite chemical mass shifts also allowed to null out the chemical mass shift by calculating the mean m/z value between the two opposite scans and remove or reduce the mass error caused by chemical mass shift. Graphical Abstract ᅟ.

Chemical Mass Shifts in a Digital Linear Ion Trap as Analytical Identity of o-, m-, and p-Xylene

NASA Astrophysics Data System (ADS)

Sun, Lulu; Xue, Bing; Huang, Zhengxu; Cheng, Ping; Ma, Li; Ding, Li; Zhou, Zhen

2018-04-01

Chemical mass shifts between isomeric ions of o-, m-, and p-xylene were measured using a digital linear ion trap, and the directions and values of the shifts were found to be correlated to the collision cross sections of the isomers. Both forward and reverse scans were used and the chemical shifts for each pair of isomers in scans of opposite directions were in opposite signs. Using different voltage settings (namely the voltage dividing ratio-VDR) of the ion trap allows adding high order field components in the quadrupole field and results in larger chemical mass shifts. The differential chemical mass shift which combined the shifts from forward and reverse scans doubled the amount of chemical shift, e.g., 0.077 Th between o- and p-xylene, enough for identification of the type of isomer without using an additional ion mobility spectrometer. The feature of equal and opposite chemical mass shifts also allowed to null out the chemical mass shift by calculating the mean m/z value between the two opposite scans and remove or reduce the mass error caused by chemical mass shift. [Figure not available: see fulltext.

Trapping spotted wing drosophila, Drosophila suzukii (Matsumura)(Diptera: Drosophilidae) with combinations of vinegar and wine, and acetic acid and ethanol

USDA-ARS?s Scientific Manuscript database

Recommendations for monitoring spotted wing drosophila (SWD) Drosophila suzukii, (Matsumura) are to use either vinegar or wine as a bait for traps. Traps baited with vinegar and traps baited with wine, in field tests in northern Oregon, captured large numbers of male and female SWD flies. Numbers of...

Cholinergic Synaptic Transmissions Were Altered after Single Sevoflurane Exposure in Drosophila Pupa

PubMed Central

Chen, Rongfa; Zhang, Tao; Kuang, Liting; Chen, Zhen; Ran, Dongzhi; Niu, Yang; Gu, Huaiyu

2015-01-01

Purpose. Sevoflurane, one of the most used general anesthetics, is widely used in clinical practice all over the world. Previous studies indicated that sevoflurane could induce neuron apoptosis and neural deficit causing query in the safety of anesthesia using sevoflurane. The present study was designed to investigate the effects of sevoflurane on electrophysiology in Drosophila pupa whose excitatory neurotransmitter is acetylcholine early after sevoflurane exposure using whole brain recording technique. Methods. Wide types of Drosophila (canton-s flies) were allocated to control and sevoflurane groups randomly. Sevoflurane groups (1% sevoflurane; 2% sevoflurane; 3% sevoflurane) were exposed to sevoflurane and the exposure lasted 5 hours, respectively. All flies were subjected to electrophysiology experiment using patch clamp 24 hours after exposure. Results. The results showed that, 24 hours after sevoflurane exposure, frequency but not the amplitude of miniature excitatory postsynaptic currents (mEPSCs) was significantly reduced (P < 0.05). Furthermore, we explored the underlying mechanism and found that calcium currents density, which partially regulated the frequency of mEPSCs, was significantly reduced after sevoflurane exposure (P < 0.05). Conclusions. All these suggested that sevoflurane could alter the mEPSCs that are related to synaptic plasticity partially through modulating calcium channel early after sevoflurane exposure. PMID:25705662

Nematocytes: Discovery and characterization of a novel anculeate hemocyte in Drosophila falleni and Drosophila phalerata.

PubMed

Bozler, Julianna; Kacsoh, Balint Z; Bosco, Giovanni

2017-01-01

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 process of

Exposure-dependent variation in cryolite induced lethality in the non-target insect, Drosophila melanogaster

PubMed Central

Podder, Sayanti

2014-01-01

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. PMID:26038671

DNA Repair in Drosophila: Mutagens, Models, and Missing Genes

PubMed Central

Sekelsky, Jeff

2017-01-01

The numerous processes that damage DNA are counterbalanced by a complex network of repair pathways that, collectively, can mend diverse types of damage. Insights into these pathways have come from studies in many different organisms, including Drosophila melanogaster. Indeed, the first ideas about chromosome and gene repair grew out of Drosophila research on the properties of mutations produced by ionizing radiation and mustard gas. Numerous methods have been developed to take advantage of Drosophila genetic tools to elucidate repair processes in whole animals, organs, tissues, and cells. These studies have led to the discovery of key DNA repair pathways, including synthesis-dependent strand annealing, and DNA polymerase theta-mediated end joining. Drosophila appear to utilize other major repair pathways as well, such as base excision repair, nucleotide excision repair, mismatch repair, and interstrand crosslink repair. In a surprising number of cases, however, DNA repair genes whose products play important roles in these pathways in other organisms are missing from the Drosophila genome, raising interesting questions for continued investigations. PMID:28154196

Interorgan Communication Pathways in Physiology: Focus on Drosophila

PubMed Central

Droujinine, Ilia A.; Perrimon, Norbert

2017-01-01

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 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. PMID:27732790

Interorgan Communication Pathways in Physiology: Focus on Drosophila.

PubMed

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.

Birth, death, and replacement of karyopherins in Drosophila.

PubMed

Phadnis, Nitin; Hsieh, Emily; Malik, Harmit S

2012-05-01

Nucleocytoplasmic transport is a broadly conserved process across eukaryotes. Despite its essential function and conserved mechanism, components of the nuclear transport apparatus have been implicated in genetic conflicts in Drosophila, especially in the male germ line. The best understood case is represented by a truncated RanGAP gene duplication that is part of the segregation distorter system in Drosophila melanogaster. Consistent with the hypothesis that the nuclear transport pathway is at the heart of mediating genetic conflicts, both nucleoporins and directionality imposing components of nuclear transport have previously been shown to evolve under positive selection. Here, we present a comprehensive phylogenomic analysis of importins (karyopherins) in Drosophila evolution. Importins are adaptor molecules that physically mediate the transport of cargo molecules and comprise the third component of the nuclear transport apparatus. We find that importins have been repeatedly gained and lost throughout various stages of Drosophila evolution, including two intriguing examples of an apparently coincident loss and gain of nonorthologous and noncanonical importin-α. Although there are a few signatures of episodic positive selection, genetic innovation in importin evolution is more evident in patterns of recurrent gene birth and loss specifically for function in Drosophila testes, which is consistent with their role in supporting host genomes defense against segregation distortion.

Go Signaling in Mushroom Bodies Regulates Sleep in Drosophila

PubMed Central

Guo, Fang; Yi, Wei; Zhou, Mingmin; Guo, Aike

2011-01-01

Study Objectives: Sleep is a fundamental physiological process and its biological mechanisms are poorly understood. In Drosophila melanogaster, heterotrimeric Go protein is abundantly expressed in the brain. However, its post-developmental function has not been extensively explored. Design: Locomotor activity was measured using the Drosophila Activity Monitoring System under a 12:12 LD cycle. Sleep was defined as periods of 5 min with no recorded activity. Results: Pan-neuronal elevation of Go signaling induced quiescence accompanied by an increased arousal threshold in flies. By screening region-specific GAL4 lines, we mapped the sleep-regulatory function of Go signaling to mushroom bodies (MBs), a central brain region which modulates memory, decision making, and sleep in Drosophila. Up-regulation of Go activity in these neurons consolidated sleep while inhibition of endogenous Go via expression of Go RNAi or pertussis toxin reduced and fragmented sleep, indicating that the Drosophila sleep requirement is affected by levels of Go activity in the MBs. Genetic interaction results showed that Go signaling serves as a neuronal transmission inhibitor in a cAMP-independent pathway. Conclusion: Go signaling is a novel signaling pathway in MBs that regulates sleep in Drosophila. Citation: Guo F; Yi W; Zhou M; Guo A. Go signaling in mushroom bodies regulates sleep in drosophila. SLEEP 2011;34(3):273-281. PMID:21358844

Female remating, sperm competition and sexual selection in Drosophila.

PubMed

Singh, Shree Ram; Singh, Bashisth N; Hoenigsberg, Hugo F

2002-09-30

Female remating is 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 affects sperm usage patterns and sexual selection. Remating is common in females of many species of Drosophila in both natural and laboratory populations. It has been reported in many insect species and also in vertebrates. Female remating is a prerequisite for sperm competition between males, and the consequences of this competition, such as sperm precedence or sperm displacement, have been reported for many species of Drosophila. Female remating is dependent on the amount of sperm stored, the male seminal fluid components, nutrition, the quantity of eggs laid, experimental design and density of flies in laboratory. Remating by a female is an insurance against male sterility and sub-fertility and increases genetic heterogeneity of female offspring. Remating gives greater female productivity in many species of Drosophila. We examined female remating with respect to sperm competition and sexual selection in Drosophila and addressed the possible benefits for females. We also reviewed the role of accessory gland fluid in remating, costs associated with remating, the genetic basis of female remating and some possible mechanisms of sperm competition in the light of last male sperm priority and paternity assurance in Drosophila and other insects. We also suggest future areas of research.

Resources for Functional Genomics Studies in Drosophila melanogaster

PubMed Central

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

2014-01-01

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

Functional Gustatory Role of Chemoreceptors in Drosophila Wings.

PubMed

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

2016-05-17

Neuroanatomical evidence argues for the presence of taste sensilla in Drosophila wings; however, the taste physiology of insect wings remains hypothetical, and a comprehensive link to mechanical functions, such as flight, wing flapping, and grooming, is lacking. Our data show that the sensilla of the Drosophila anterior wing margin respond to both sweet and bitter molecules through an increase in cytosolic Ca(2+) levels. Conversely, genetically modified flies presenting a wing-specific reduction in chemosensory cells show severe defects in both wing taste signaling and the exploratory guidance associated with chemodetection. In Drosophila, the chemodetection machinery includes mechanical grooming, which facilitates the contact between tastants and wing chemoreceptors, and the vibrations of flapping wings that nebulize volatile molecules as carboxylic acids. Together, these data demonstrate that the Drosophila wing chemosensory sensilla are a functional taste organ and that they may have a role in the exploration of ecological niches. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

PubMed

Ventrella, Emanuela; Adamski, Zbigniew; Chudzińska, Ewa; Miądowicz-Kobielska, Mariola; Marciniak, Paweł; Büyükgüzel, Ender; Büyükgüzel, Kemal; Erdem, Meltem; Falabella, Patrizia; Scrano, Laura; Bufo, Sabino Aurelio

2016-01-01

Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture.

Quantifying Drosophila food intake: comparative analysis of current methodology

PubMed Central

Deshpande, Sonali A.; Carvalho, Gil B.; Amador, Ariadna; Phillips, Angela M.; Hoxha, Sany; Lizotte, Keith J.; Ja, William W.

2014-01-01

Food intake is a fundamental parameter in animal studies. Despite the prevalent use of Drosophila in laboratory research, precise measurements of food intake remain challenging in this model organism. Here, we compare several common Drosophila feeding assays: the Capillary Feeder (CAFE), food-labeling with a radioactive tracer or a colorimetric dye, and observations of proboscis extension (PE). We show that the CAFE and radioisotope-labeling provide the most consistent results, have the highest sensitivity, and can resolve differences in feeding that dye-labeling and PE fail to distinguish. We conclude that performing the radiolabeling and CAFE assays in parallel is currently the best approach for quantifying Drosophila food intake. Understanding the strengths and limitations of food intake methodology will greatly advance Drosophila studies of nutrition, behavior, and disease. PMID:24681694

Neuroprotective efficacy of Bacopa monnieri against rotenone induced oxidative stress and neurotoxicity in Drosophila melanogaster.

PubMed

Hosamani, Ravikumar; Muralidhara

2009-11-01

Bacopa monnieri, Linn. (Brahmi, BM), traditionally used to improve mental health in Indian ayurvedic system of medicine is known to possess various neuropharmacolgical properties. In the recent past, Drosophila has been widely used as a model to study various neurodegenerative diseases. Environmental toxins like rotenone, a specific inhibitor of complex I is employed to increase oxidative stress mediated neuropathology and sporadic Parkinson's disease. In this study, we examined the neuroprotective properties of BM against rotenone induced oxidative damage and neurotoxicity. Flies (Oregon K strain, adult males) exposed to a standardized BM powder for 7 days in the diet exhibited significant diminution in the levels of endogenous oxidative markers viz., malondialdehyde, hydroperoxide and protein carbonyl content. Further, BM offered complete protection against rotenone (500 microM) induced oxidative stress and markedly inhibited dopamine depletion (head region, 33%; body region, 44%) in flies. Flies exposed to rotenone+BM exhibited a lower incidence of mortality (40-66% protection) and performed better in a negative geotaxis assay (45-65%) both suggesting the neuroprotective potential of BM. Interestingly, BM also conferred significant resistance (43-54% protection) in a paraquat oxidative stress bioassay. The neuroprotective effects of BM were highly comparable to those of a commercially available Brahmi preparation. Although the precise mechanism/s underlying the neuroprotective efficacy of BM are not clear, it is hypothesized that it is wholly or in part related to its ability to mitigate rotenone induced oxidative stress. Further, our approach confirms the utility of the Drosophila model in screening putative neuroprotective phytomedicines prior to their use in mammalian models.

Low-resolution structure of Drosophila translin

PubMed Central

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

Copper homeostasis gene discovery in Drosophila melanogaster.

PubMed

Norgate, Melanie; Southon, Adam; Zou, Sige; Zhan, Ming; Sun, Yu; Batterham, Phil; Camakaris, James

2007-06-01

Recent studies have shown a high level of conservation between Drosophila melanogaster and mammalian copper homeostasis mechanisms. These studies have also demonstrated the efficiency with which this species can be used to characterize novel genes, at both the cellular and whole organism level. As a versatile and inexpensive model organism, Drosophila is also particularly useful for gene discovery applications and thus has the potential to be extremely useful in identifying novel copper homeostasis genes and putative disease genes. In order to assess the suitability of Drosophila for this purpose, three screening approaches have been investigated. These include an analysis of the global transcriptional response to copper in both adult flies and an embryonic cell line using DNA microarray analysis. Two mutagenesis-based screens were also utilized. Several candidate copper homeostasis genes have been identified through this work. In addition, the results of each screen were carefully analyzed to identify any factors influencing efficiency and sensitivity. These are discussed here with the aim of maximizing the efficiency of future screens and the most suitable approaches are outlined. Building on this information, there is great potential for the further use of Drosophila for copper homeostasis gene discovery.

T-Box Genes in Drosophila Mesoderm Development.

PubMed

Reim, I; Frasch, M; Schaub, C

2017-01-01

In Drosophila there are eight genes encoding transcription factors of the T-box family, which are known to exert a variety of crucial developmental functions during ectodermal patterning processes, neuronal cell specification, mesodermal tissue development, and the development of extraembryonic tissues. In this review, we focus on the prominent roles of Drosophila T-box genes in mesodermal tissues. First, we describe the contributions of brachyenteron (byn) and optomotor-blind-related-gene-1 (org-1) to the development of the visceral mesoderm. Second, we provide an overview on the functions of the three Dorsocross paralogs (Doc1-3) and the two Tbx20-related paralogs (midline and H15) during Drosophila heart development. Third, we portray the roles of org-1 and midline/H15 in the specification of individual body wall and organ-attached muscles, including the function of org-1 in the transdifferentiation of certain heart-attached muscles during metamorphosis. The functional analysis of these evolutionarily conserved T-box genes, along with their interactions with other types of transcription factors and various signaling pathways, has provided key insights into the regulation of Drosophila visceral mesoderm, muscle, and heart development. © 2017 Elsevier Inc. All rights reserved.

Organization of descending neurons in Drosophila melanogaster.

PubMed

Hsu, Cynthia T; Bhandawat, Vikas

2016-02-03

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

Within-group male relatedness reduces harm to females in Drosophila

PubMed Central

Allen, Felicity; Wigby, Stuart; Pizzari, Tommaso

2018-01-01

Resolving the mechanisms that switch competition to cooperation is key to understand biological organization1. This is particularly relevant for intrasexual competition, which often leads to males harming females2. Recent theory proposes that kin selection may modulate female harm by relaxing competition among relatives3–5. We experimentally manipulated the relatedness of groups of male Drosophila melanogaster competing over females to demonstrate that, as expected, within group relatedness inhibits male competition and female harm. Females exposed to three brothers unrelated to the female had higher lifetime reproductive success and slower reproductive ageing compared to females exposed to triplets of males unrelated to each other. Triplets of brothers also fought less with each other, courted females less intensively and lived longer than triplets of unrelated males. However, associations among brothers may be vulnerable to invasion by minorities of unrelated males: when two brothers were matched with an unrelated male, the latter sired on average twice as many offspring as either brother. These results demonstrate that relatedness can profoundly affect fitness through its modulation of intrasexual competition, as flies plastically adjust sexual behaviour in a way consistent with kin selection theory. PMID:24463521

The effect of water presence on the photocatalytic oxidation of benzene, toluene, ethylbenzene and m-xylene in the gas-phase

NASA Astrophysics Data System (ADS)

Korologos, Christos A.; Philippopoulos, Constantine J.; Poulopoulos, Stavros G.

2011-12-01

In the present work, the gas-solid heterogeneous photocatalytic oxidation of benzene, toluene, ethylbenzene and m-xylene (BTEX) over UV-irradiated titanium dioxide was studied in an annular reactor operated in the CSTR (continuous stirred-tank reactor) mode. GC-FID and GC-MS were used for analysing reactor inlet and outlet streams. Initial BTEX concentrations were in the low parts per million (ppmv) range, whereas the water concentration was in the range of 0-35,230 ppmv and the residence time varied from 50 to 210 s. The effect of water addition on the photocatalytic process showed strong dependence on the type of the BTEX and the water vapour concentration. The increase in residence time resulted in a considerable increase in the conversion achieved for all compounds and experimental conditions. There was a clear interaction between residence time and water presence regarding the effect on conversions achieved. It was established that conversions over 95% could be achieved by adjusting appropriately the experimental conditions and especially the water concentration in the reactor. In all cases, no by-products were detected above the detection limit and carbon dioxide was the only compound detected. Finally, various Langmuir-Hinshelwood kinetic models have been tested in the analysis of the experimental data obtained. The kinetic data obtained confirmed that water had an active participation in the photocatalytic reactions of benzene, toluene, ethylbenzene and m-xylene since the model involving reaction of BTEX and water adsorbed on different active sites yielded the most successful fitting to the experimental results for the first three compounds, whereas the kinetic model based on the assumption that reaction between VOC and water dissociatively adsorbed on the photocatalyst takes place was the most appropriate in the case of m-xylene.

Drosophila Genetic Resource and Stock Center; The National BioResource Project.

PubMed

Yamamoto, Masa-Toshi

2010-01-01

The fruit fly, Drosophila melanogaster, is not categorized as a laboratory animal, but it is recognised as one of the most important model organisms for basic biology, life science, and biomedical research. This tiny fly continues to occupy a core place in genetics and genomic approaches to studies of biology and medicine. The basic principles of genetics, including the variations of phenotypes, mutations, genetic linkage, meiotic chromosome segregation, chromosome aberrations, recombination, and precise mapping of genes by genetic as well as cytological means, were all derived from studies of Drosophila. Recombinant DNA technology was developed in the 1970s and Drosophila DNA was the first among multicellular organisms to be cloned. It provided a detailed characterization of genes in combination of classical cytogenetic data. Drosophila thus became the pioneering model organism for various fields of life science research into multicellular organisms. Here, I briefly describe the history of Drosophila research and provide a few examples of the application of the abundant genetic resources of Drosophila to basic biology and medical investigations. A Japanese national project, the National BioResource Project (NBRP) for collection, maintainance, and provision of Drosophila resources, that is well known and admired by researchers in other countries as an important project, is also briefly described.

Generation of genome-modified Drosophila cell lines using SwAP.

PubMed

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.

Headspace-mass spectrometry determination of benzene, toluene and the mixture of ethylbenzene and xylene isomers in soil samples using chemometrics.

PubMed

Esteve-Turrillas, F A; Armenta, S; Garrigues, S; Pastor, A; de la Guardia, M

2007-03-21

A simple and fast method has been developed for the determination of benzene, toluene and the mixture of ethylbenzene and xylene isomers (BTEX) in soils. Samples were introduced in 10 mL standard glass vials of a headspace (HS) autosampler together with 150 microL of 2,6,10,14-tetramethylpentadecane, heated at 90 degrees C for 10 min and introduced in the mass spectrometer by using a transfer line heated at 250 degrees C as interface. The volatile fraction of samples was directly introduced into the source of the mass spectrometer which was scanned from m/z 75 to 110. A partial least squares (PLS) multivariate calibration approach based on a classical 3(3) calibration model was build with mixtures of benzene, toluene and o-xylene in 2,6,10,14-tetramethylpentadecane for BTEX determination. Results obtained for BTEX analysis by HS-MS in different types of soil samples were comparables to those obtained by the reference HS-GC-MS procedure. So, the developed procedure allowed a fast identification and prediction of BTEX present in the samples without a prior chromatographic separation.

Analysis of the hypoxia-sensing pathway in Drosophila melanogaster

PubMed Central

Arquier, Nathalie; Vigne, Paul; Duplan, Eric; Hsu, Tien; Therond, Pascal P.; Frelin, Christian; D'Angelo, Gisela

2005-01-01

The mechanism by which hypoxia induces gene transcription involves the inhibition of HIF-1α (hypoxia-inducible factor-1 α subunit) PHD (prolyl hydroxylase) activity, which prevents the VHL (von Hippel-Lindau)-dependent targeting of HIF-1α to the ubiquitin/proteasome pathway. HIF-1α thus accumulates and promotes gene transcription. In the present study, first we provide direct biochemical evidence for the presence of a conserved hypoxic signalling pathway in Drosophila melanogaster. An assay for 2-oxoglutarate-dependent dioxygenases was developed using Drosophila embryonic and larval homogenates as a source of enzyme. Drosophila PHD has a low substrate specificity and hydroxylates key proline residues in the ODD (oxygen-dependent degradation) domains of human HIF-1α and Similar, the Drosophila homologue of HIF-1α. The enzyme promotes human and Drosophila [35S]VHL binding to GST (glutathione S-transferase)–ODD-domain fusion protein. Hydroxylation is enhanced by proteasomal inhibitors and was ascertained using an anti-hydroxyproline antibody. Secondly, by using transgenic flies expressing a fusion protein that combined an ODD domain and the green fluorescent protein (ODD–GFP), we analysed the hypoxic cascade in different embryonic and larval tissues. Hypoxic accumulation of the reporter protein was observed in the whole tracheal tree, but not in the ectoderm. Hypoxic stabilization of ODD–GFP in the ectoderm was restored by inducing VHL expression in these cells. These results show that Drosophila tissues exhibit different sensitivities to hypoxia. PMID:16176182

Drosophila adult and larval pheromones modulate larval food choice

PubMed Central

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

2014-01-01

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

Research progress on Drosophila visual cognition in China.

PubMed

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.

Homophila: human disease gene cognates in Drosophila

PubMed Central

Chien, Samson; Reiter, Lawrence T.; Bier, Ethan; Gribskov, Michael

2002-01-01

Although many human genes have been associated with genetic diseases, knowing which mutations result in disease phenotypes often does not explain the etiology of a specific disease. Drosophila melanogaster provides a powerful system in which to use genetic and molecular approaches to investigate human genetic diseases. Homophila is an intergenomic resource linking the human and fly genomes in order to stimulate functional genomic investigations in Drosophila that address questions about genetic disease in humans. Homophila provides a comprehensive linkage between the disease genes compiled in Online Mendelian Inheritance in Man (OMIM) and the complete Drosophila genomic sequence. Homophila is a relational database that allows searching based on human disease descriptions, OMIM number, human or fly gene names, and sequence similarity, and can be accessed at http://homophila.sdsc.edu. PMID:11752278

Functional requirements driving the gene duplication in 12 Drosophila species.

PubMed

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.

Hazardous effects of effluent from the chrome plating industry: 70 kDa heat shock protein expression as a marker of cellular damage in transgenic Drosophila melanogaster (hsp70-lacZ).

PubMed Central

Mukhopadhyay, Indranil; Saxena, Daya Krishna; Chowdhuri, Debapratim Kar

2003-01-01

Hazardous effects of an effluent from the chrome plating industry were examined by exposing transgenic Drosophila melanogaster (hsp70-lacZ) to various concentrations (0.05, 0.1, 1.0, 10.0, and 100.0 micro L/mL) of the effluent through diet. The emergence pattern of adult flies was affected, along with impaired reproductive performance at the higher dietary concentrations of the effluent. Interestingly, the effect of the effluent was more pronounced in male than in female flies. The effect of the effluent on development of adult flies was concurrent with the expression pattern of the heat shock protein 70 gene (hsp70), both in larval tissues and in the reproductive organs of adult flies. We observed a dose- and time-dependent expression of hsp70 in third instar larvae exposed for different time intervals. Absence of hsp70 expression in larvae exposed to 0.1 micro L/mL of the effluent indicated that this is the highest nontoxic concentration for Drosophila. The stress gene assay in the reproductive organs of adult flies revealed hsp70 expression in the testis of male flies only. However, trypan blue dye exclusion tests in these tissues indicate tissue damage in the male accessory gland of adult flies, which was further confirmed by ultrastructural observations. In the present study we demonstrate the utility of transgenic Drosophila as an alternative animal model for evaluating hazardous effects of the effluent from the chrome plating industry and further reveal the cytoprotective role of hsp70 and its expression as an early marker in environmental risk assessment. PMID:14644668

Removal of benzene, toluene, xylene and styrene by biotrickling filters and identification of their interactions

PubMed Central

Li, Enze; Li, Jianjun; Zeng, Peiyuan; Feng, Rongfang; Xu, Meiying

2018-01-01

Biotrickling filters (BTFs) are becoming very potential means to purify waste gases containing multiple VOC components, but the removal of the waste gases by BTF has been a major challenge due to the extremely complicated interactions among the components. Four biotrickling filters packed with polyurethane foam were employed to identify the interactions among four aromatic compounds (benzene, toluene, xylene and styrene). The elimination capacities obtained at 90% of removal efficiency for individual toluene, styrene and xylene were 297.02, 225.27 and 180.75 g/m3h, respectively. No obvious removal for benzene was observed at the inlet loading rates ranging from 20 to 450 g/m3h. The total elimination capacities for binary gases significantly decreased in all biotrickling filters. However, the removal of benzene was enhanced in the presence of other gases. The removal capacities of ternary and quaternary gases were further largely lowered. High-throughput sequencing results revealed that microbial communities changed greatly with the composition of gases, from which we found that: all samples were dominated either by the genus Achromobacter or the Burkholderia. Different gaseous combination enriched or inhibited some microbial species. Group I includes samples of BTFs treating single and binary gases and was dominated by the genus Achromobacter, with little Burkholderia inside. Group II includes the rest of the samples taken from BTFs domesticated with ternary and quaternary gases, and was dominated by the genus Burkholderia, with little Achromobacter detected. These genera were highly associated with the biodegradation of benzene series in BTFs. PMID:29293540

Drosophila melanogaster as a Versatile Model Organism in Food and Nutrition Research.

PubMed

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.

Drosophila as a model to study cardiac aging

PubMed Central

Nishimura, Mayuko; Ocorr, Karen; Bodmer, Rolf; Cartry, Jérôme

2010-01-01

With age, cardiac performance declines progressively and the risk of heart disease, a primary cause of mortality, rises dramatically. As the elderly population continues to increase, it is critical to gain a better understanding of the genetic influences and modulatory factors that impact cardiac aging. In an attempt to determine the relevance and utility of the Drosophila heart in unraveling the genetic mechanisms underlying cardiac aging, a variety of heart performance assays have recently been developed to quantify Drosophila heart performance that permit the use of the fruit fly to investigate the heart’s decline with age. As for the human heart, Drosophila heart function also deteriorates with age. Notably, with progressive age the incidence of cardiac arrhythmias, myofibrillar disorganization and susceptibility to heart dysfunction and failure all increase significantly. We review here the evidence for an involvement of the insulin-TOR pathway, the KATP channel subunit dSur, the KCNQ potassium channel, as well as Dystrophin and Myosin in fly cardiac aging, and discuss the utility of the Drosophila heart model for cardiac aging studies. PMID:21130861

Experimental control and characterization of autophagy in Drosophila.

PubMed

Juhasz, Gabor; Neufeld, Thomas P

2008-01-01

Insects such as the fruit fly Drosophila melanogaster, which fundamentally reorganize their body plan during metamorphosis, make extensive use of autophagy for their normal development and physiology. In the fruit fly, the hepatic/adipose organ known as the fat body accumulates nutrient stores during the larval feeding stage. Upon entering metamorphosis, as well as in response to starvation, these nutrients are mobilized through a massive induction of autophagy, providing support to other tissues and organs during periods of nutrient deprivation. High levels of autophagy are also observed in larval tissues destined for elimination, such as the salivary glands and larval gut. Drosophila is emerging as an important system for studying the functions and regulation of autophagy in an in vivo setting. In this chapter we describe reagents and methods for monitoring autophagy in Drosophila, focusing on the larval fat body. We also describe methods for experimentally activating and inhibiting autophagy in this system and discuss the potential for genetic analysis in Drosophila to identify novel genes involved in autophagy.

Real-time monitoring of benzene, toluene, and p-xylene in a photoreaction chamber with a tunable mid-infrared laser and ultraviolet differential optical absorption spectroscopy.

PubMed

Parsons, Matthew T; Sydoryk, Ihor; Lim, Alan; McIntyre, Thomas J; Tulip, John; Jäger, Wolfgang; McDonald, Karen

2011-02-01

We describe the implementation of a mid-infrared laser-based trace gas sensor with a photoreaction chamber, used for reproducing chemical transformations of benzene, toluene, and p-xylene (BTX) gases that may occur in the atmosphere. The system performance was assessed in the presence of photoreaction products including aerosol particles. A mid-infrared external cavity quantum cascade laser (EC-QCL)-tunable from 9.41-9.88 μm (1012-1063 cm(-1))-was used to monitor gas phase concentrations of BTX simultaneously and in real time during chemical processing of these compounds with hydroxyl radicals in a photoreaction chamber. Results are compared to concurrent measurements using ultraviolet differential optical absorption spectroscopy (UV DOAS). The EC-QCL based system provides quantitation limits of approximately 200, 200, and 600 parts in 10(9) (ppb) for benzene, toluene, and p-xylene, respectively, which represents a significant improvement over our previous work with this laser system. Correspondingly, we observe the best agreement between the EC-QCL measurements and the UV DOAS measurements with benzene, followed by toluene, then p-xylene. Although BTX gas-detection limits are not as low for the EC-QCL system as for UV DOAS, an unidentified by-product of the photoreactions was observed with the EC-QCL, but not with the UV DOAS system.

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

PubMed Central

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

2015-01-01

The Drosophila pheromone cis-11-octadecenyl acetate (cVA) is used as pheromone throughout the melanogaster group and fulfils a primary role in sexual and social behaviours. Here, we found that Drosophila suzukii, an invasive pest that oviposits in undamaged ripe fruit, does not produce cVA. In fact, its production site, the ejaculatory bulb, is atrophied. Despite loss of cVA production, its receptor, Or67d, and cognate sensillum, T1, which are essential in cVA-mediated behaviours, were fully functional. However, T1 expression was dramatically reduced in D. suzukii, and the corresponding antennal lobe glomerulus, DA1, minute. Behavioural responses to cVA depend on the input balance of Or67d neurons (driving cVA-mediated behaviours) and Or65a neurons (inhibiting cVA-mediated behaviours). Accordingly, the shifted input balance in D. suzukii has reversed cVA's role in sexual behaviour: perfuming D. suzukii males with Drosophila melanogaster equivalents of cVA strongly reduced mating rates. cVA has thus evolved from a generic sex pheromone to a heterospecific signal that disrupts mating in D. suzukii, a saltational shift, mediated through offsetting the input balance that is highly conserved in congeneric species. This study underlines that dramatic changes in a species' sensory preference can result from rather ‘simple’ numerical shifts in underlying neural circuits. PMID:25716789

Genome-wide comparative analysis of four Indian Drosophila species.

PubMed

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.

Insights From Natural Host-Parasite Interactions: The Drosophila Model

PubMed Central

Keebaugh, Erin S.; Schlenke, Todd A.

2013-01-01

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

Drosophila increase exploration after visually detecting predators.

PubMed

de la Flor, Miguel; Chen, Lijian; Manson-Bishop, Claire; Chu, Tzu-Chun; Zamora, Kathya; Robbins, Danielle; Gunaratne, Gemunu; Roman, Gregg

2017-01-01

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.

Drosophila increase exploration after visually detecting predators

PubMed Central

Manson-Bishop, Claire; Chu, Tzu-Chun; Zamora, Kathya; Robbins, Danielle; Gunaratne, Gemunu

2017-01-01

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. PMID:28746346

Optogenetic pacing in Drosophila melanogaster (Conference Presentation)

NASA Astrophysics Data System (ADS)

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

2016-03-01

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

Optogenetic pacing in Drosophila models (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wu, Penghe; Li, Airong; Men, Jing; Tans, Rudolph E.; Zhou, Chao

2017-02-01

The Drosophila melanogaster shares many similarities with vertebrates in heart development. Comparison of heart structural and functional characteristic between male and female Drosophila melanogaster at different developmental stages is helpful to understand heart morphogenesis and function for different genders. And also, it opens up the possibility to uncover the role of sex-related genes in heart development. In this longitudinal study, we cultured and tracked dozens of individually labeled flies throughout their lifecycle. The heart characteristic was measured at different developmental stages during culturing. The gender of each individual fly was determined by adult stage so that the collected data of early stages could be classified to male or female group. We adapted a high-speed optical coherence microscopy (OCM) system with axial and transverse resolution of 2um and 4um, respectively, to perform non-invasive M-mode imaging at a frame rate of 132Hz in Drosophila heart at third instar larva, early pupa and adult stage. Based on those GPU processed M-mode OCM images, we segmented the fly heart region and then quantified the cardiac structural and functional parameters such as heart rate, heart chamber size and so on. Despite large variances of wild type Drosophila in terms of some cardiac characteristic, our results suggest that the heart rate is lower for male flies than for female flies, especially at third instar larva stage. The end diastolic area (EDA) and end systolic area (ESA) of the heart are both slightly larger in female flies than in male flies at larva and adult stage. In summary, we showed gender differences of wild type drosophila in heart functional and structural characteristic.

Organization of descending neurons in Drosophila melanogaster

PubMed Central

Hsu, Cynthia T.; Bhandawat, Vikas

2016-01-01

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

Apoptosis in Drosophila: which role for mitochondria?

PubMed

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

2016-03-01

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

Erythritol and Lufenuron detrimentally alter age structure of Wild Spotted Wing Drosophila (SWD) Drosophila suzukii (Diptera: Drosophilidae) populations in blueberry and blackberry

USDA-ARS?s Scientific Manuscript database

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 (...

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

USDA-ARS?s Scientific Manuscript database

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 suzukii population response to environment and management strategies

USDA-ARS?s Scientific Manuscript database

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...

Developmental constraints and convergent evolution in Drosophila sex comb formation.

PubMed

Atallah, Joel; Liu, Nana Hou; Dennis, Peter; Hon, Andy; Larsen, Ellen W

2009-01-01

The most complex and diverse secondary sexual character in Drosophila is the sex comb (SC), an arrangement of modified bristles on the forelegs of a subclade of male fruit flies. We examined SC formation in six representative nonmodel fruit fly species, in an effort to understand how the variation in comb patterning arises. We first compared SC development in two species with relatively small combs, Drosophila takahashii, where the SCs remain approximately transverse, and Drosophila biarmipes, where two rows of SC teeth rotate and move in an anterior direction relative to other bristle landmarks. We then analyzed comb ontogeny in species with prominent extended SCs parallel to the proximodistal axis, including Drosophila ficusphila and species of the montium subgroup. Our study allowed us to identify two general methods of generating longitudinal combs on the tarsus, and we showed that a montium subgroup species (Drosophila nikananu) with a comb convergently similar in size, orientation and position to the model organism Drosophila melanogaster, forms its SC through a different developmental mechanism. We also found that the protein product of the leg patterning gene, dachshund (dac), is strongly reduced in the SC in all species, but not in other bristles. Our results suggest that an apparent constraint on SC position in the adult may be attributable to at least two different lineage-specific developmental processes, although external forces could also play a role.

Fruitful research: drug target discovery for neurodegenerative diseases in Drosophila.

PubMed

Konsolaki, Mary

2013-12-01

Although vertebrate model systems have obvious advantages in the study of human disease, invertebrate organisms have contributed enormously to this field as well. The conservation of genome structure and physiology among organisms poses unexpected peculiarities, and the redundancy in certain gene families or the presence of polymorphisms that can slightly alter gene expression can, in certain instances, bring invertebrate systems, such as Drosophila, closer to humans than mice and vice versa. This necessitates the analysis of disease pathways in multiple model organisms. The author highlights findings from Drosophila models of neurodegenerative diseases that have occurred in the past few years. She also highlights and discusses various molecular, genetic and genomic tools used in flies, as well as methods for generating disease models. Finally, the author describes Drosophila models of Alzheimer's, Parkinson's tri-nucleotide repeat diseases, and Fragile X syndrome and summarizes insights in disease mechanisms that have been discovered directly in fly models. Full genome genetic screens in Drosophila can lead to the rapid identification of drug target candidates that can be subsequently validated in a vertebrate system. In addition, the Drosophila models of neurodegeneration may often show disease phenotypes that are absent in equivalent mouse models. The author believes that the extensive contribution of Drosophila to both new disease drug target discovery, in addition to target validation, makes them indispensible to drug discovery and development.

Drosophila melanogaster, a genetic model system for alcohol research.

PubMed

Guarnieri, Douglas J; Heberlein, Ulrike

2003-01-01

In its natural environment, which consists of fermenting plant materials, the fruit fly Drosophila melanogaster encounters high levels of ethanol. Flies are well equipped to deal with the toxic effects of ethanol; they use it as an energy source and for lipid biosynthesis. The primary ethanol-metabolizing pathway in flies involves the enzymes alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH); their role in adaptation to ethanol-rich environments has been studied extensively. The similarity between Drosophila and mammals is not restricted to the manner in which they metabolize ethanol; behaviors elicited by ethanol exposure are also remarkably similar in these organisms. Flies show signs of acute intoxication, which range from locomotor stimulation at low doses to complete sedation at higher doses, they develop tolerance upon intermittent ethanol exposure, and they appear to like ethanol, showing preference for ethanol-containing media. Molecular genetic analysis of ethanol-induced behaviors in Drosophila, while still in its early stages, has already revealed some surprising parallels with mammals. The availability of powerful tools for genetic manipulation in Drosophila, together with the high degree of conservation at the genomic level, make Drosophila a promising model organism to study the mechanism by which ethanol regulates behavior and the mechanisms underlying the organism's adaptation to long-term ethanol exposure.

A comparative study to evaluate liquid dish washing soap as an alternative to xylene and alcohol in deparaffinization and hematoxylin and eosin staining.

PubMed

Pandey, Pinki; Dixit, Alok; Tanwar, Aparna; Sharma, Anuradha; Mittal, Sanjeev

2014-07-01

Our study presents a new deparaffinizing and hematoxylin and eosin (H and E) staining method that involves the use of easily available, nontoxic and eco-friendly liquid diluted dish washing soap (DWS) by completely eliminating expensive and hazardous xylene and alcohol from deparaffinizing and rehydration prior to staining, staining and from dehydration prior to mounting. The aim was to evaluate and compare the quality of liquid DWS treated xylene and alcohol free (XAF) sections with that of the conventional H and E sections. A total of 100 paraffin embedded tissue blocks from different tissues were included. From each tissue block, one section was stained with conventional H and E (normal sections) and the other with XAF H and E (soapy sections) staining method. Slides were scored using five parameters: Nuclear, cytoplasmic, clarity, uniformity, and crispness of staining. Z-test was used for statistical analysis. Soapy sections scored better for cytoplasmic (90%) and crisp staining (95%) with a statistically significant difference. Whereas for uniformity of staining, normal sections (88%) scored over soapy sections (72%) (Z = 2.82, P < 0.05). For nuclear (90%) and clarity of staining (90%) total scored favored soapy sections, but the difference was not statistically significant. About 84% normal sections stained adequately for diagnosis when compared with 86% in soapy sections (Z = 0.396, P > 0.05). Liquid DWS is a safe and efficient alternative to xylene and alcohol in deparaffinization and routine H and E staining procedure. We are documenting this project that can be used as a model for other histology laboratories.

Preparation of Drosophila central neurons for in situ patch clamping.

PubMed

Ryglewski, Stefanie; Duch, Carsten

2012-10-15

Short generation times and facile genetic techniques make the fruit fly Drosophila melanogaster an excellent genetic model in fundamental neuroscience research. Ion channels are the basis of all behavior since they mediate neuronal excitability. The first voltage gated ion channel cloned was the Drosophila voltage gated potassium channel Shaker(1,2). Toward understanding the role of ion channels and membrane excitability for nervous system function it is useful to combine powerful genetic tools available in Drosophila with in situ patch clamp recordings. For many years such recordings have been hampered by the small size of the Drosophila CNS. Furthermore, a robust sheath made of glia and collagen constituted obstacles for patch pipette access to central neurons. Removal of this sheath is a necessary precondition for patch clamp recordings from any neuron in the adult Drosophila CNS. In recent years scientists have been able to conduct in situ patch clamp recordings from neurons in the adult brain(3,4) and ventral nerve cord of embryonic(5,6), larval(7,8,9,10), and adult Drosophila(11,12,13,14). A stable giga-seal is the main precondition for a good patch and depends on clean contact of the patch pipette with the cell membrane to avoid leak currents. Therefore, for whole cell in situ patch clamp recordings from adult Drosophila neurons must be cleaned thoroughly. In the first step, the ganglionic sheath has to be treated enzymatically and mechanically removed to make the target cells accessible. In the second step, the cell membrane has to be polished so that no layer of glia, collagen or other material may disturb giga-seal formation. This article describes how to prepare an identified central neuron in the Drosophila ventral nerve cord, the flight motoneuron 5 (MN5(15)), for somatic whole cell patch clamp recordings. Identification and visibility of the neuron is achieved by targeted expression of GFP in MN5. We do not aim to explain the patch clamp technique

Adsorption of benzene, toluene, and xylene by two tetramethylammonium-smectites having different charge densities

USGS Publications Warehouse

Lee, Jiunn-Fwu; Mortland, Max M.; Chiou, Cary T.; Kite, Daniel E.; Boyd, Stephen A.

1990-01-01

A high-charge smectite from Arizona [cation-exchange capacity (CEC) = 120 meq/100 g] and a low-charge smectite from Wyoming (CEC = 90 meq/100 g) were used to prepare homoionic tetramethylammonium (TMA)-clay complexes. The adsorption of benzene, toluene, and o-xylene as vapors by the dry TMA-clays and as solutes from water by the wet TMA-clays was studied. The adsorption of the organic vapors by the dry TMA-smectite samples was strong and apparently consisted of interactions with both the aluminosilicate mineral surfaces and the TMA exchange ions in the interlayers. In the adsorption of organic vapors, the closer packing of TMA ions in the dry high-charge TMA-smectite, compared with the dry low-charge TMA-smectite, resulted in a somewhat higher degree of shape-selective adsorption of benzene, toluene, and xylene. In the presence of water, the adsorption capacities of both samples for the aromatic compounds were significantly reduced, although the uptake of benzene from water by the low-charge TMA-smectite was still substantial. This lower sorption capacity was accompanied by increased shape-selectivity for the aromatic compounds. The reduction in uptake and increased selectivity was much more pronounced for the water-saturated, high-charge TMA-smectite than for the low-charge TMA-smectite. Hydration of the TMA exchange ions and/or the mineral surfaces apparently reduced the accessibility of the aromatic molecules to interlamellar regions. The resulting water-induced sieving effect was greater for the high-charge TMA-smectite due to the higher density of exchanged TMA-ions. The low-charge Wyoming TMA-smectite was a highly effective adsorbent for removing benzene from water and may be useful for purifying benzene-contaminated water.

Biochemical and Functional Analysis of Drosophila-Sciara Chimeric Sex-Lethal Proteins

PubMed Central

Ruiz, María Fernanda; Sarno, Francesca; Zorrilla, Silvia; Rivas, Germán; Sánchez, Lucas

2013-01-01

Background The Drosophila SXL protein controls sex determination and dosage compensation. It is a sex-specific factor controlling splicing of its own Sxl pre-mRNA (auto-regulation), tra pre-mRNA (sex determination) and msl-2 pre-mRNA plus translation of msl-2 mRNA (dosage compensation). Outside the drosophilids, the same SXL protein has been found in both sexes so that, in the non-drosophilids, SXL does not appear to play the key discriminating role in sex determination and dosage compensation that it plays in Drosophila. Comparison of SXL proteins revealed that its spatial organisation is conserved, with the RNA-binding domains being highly conserved, whereas the N- and C-terminal domains showing significant variation. This manuscript focuses on the evolution of the SXL protein itself and not on regulation of its expression. Methodology Drosophila-Sciara chimeric SXL proteins were produced. Sciara SXL represents the non-sex-specific function of ancient SXL in the non-drosophilids from which presumably Drosophila SXL evolved. Two questions were addressed. Did the Drosophila SXL protein have affected their functions when their N- and C-terminal domains were replaced by the corresponding ones of Sciara? Did the Sciara SXL protein acquire Drosophila sex-specific functions when the Drosophila N- and C-terminal domains replaced those of Sciara? The chimeric SXL proteins were analysed in vitro to study their binding affinity and cooperative properties, and in vivo to analyse their effect on sex determination and dosage compensation by producing Drosophila flies that were transgenic for the chimeric SXL proteins. Conclusions The sex-specific properties of extant Drosophila SXL protein depend on its global structure rather than on a specific domain. This implies that the modifications, mainly in the N- and C-terminal domains, that occurred in the SXL protein during its evolution within the drosophilid lineage represent co-evolutionary changes that determine the appropriate

Mobile phone electromagnetic radiation activates MAPK signaling and regulates viability in Drosophila.

PubMed

Lee, Kyu-Sun; Choi, Jong-Soon; Hong, Sae-Yong; Son, Tae-Ho; Yu, Kweon

2008-07-01

Mobile phones are widely used in the modern world. However, biological effects of electromagnetic radiation produced by mobile phones are largely unknown. In this report, we show biological effects of the mobile phone 835 MHz electromagnetic field (EMF) in the Drosophila model system. When flies were exposed to the specific absorption rate (SAR) 1.6 W/kg, which is the proposed exposure limit by the American National Standards Institute (ANSI), more than 90% of the flies were viable even after the 30 h exposure. However, in the SAR 4.0 W/kg strong EMF exposure, viability dropped from the 12 h exposure. These EMF exposures triggered stress response and increased the production of reactive oxygen species. The EMF exposures also activated extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling, but not p38 kinase signaling. Interestingly, SAR 1.6 W/kg activated mainly ERK signaling and expression of an anti-apoptotic gene, whereas SAR 4.0 W/kg strongly activated JNK signaling and expression of apoptotic genes. In addition, SAR 4.0 W/kg amplified the number of apoptotic cells in the fly brain. These findings demonstrate that the exposure limit on electromagnetic radiation proposed by ANSI triggered ERK-survival signaling but the strong electromagnetic radiation activated JNK-apoptotic signaling in Drosophila.

Alightment of Spotted Wing Drosophila (Diptera: Drosophilidae) on Odorless Disks Varying in Color.

PubMed

Kirkpatrick, D M; McGhee, P S; Hermann, S L; Gut, L J; Miller, J R

2016-02-01

Methods for trapping spotted wing drosophila, Drosophila suzukii (Matsmura) (Diptera: Drosophilidae), have not yet been optimized for detecting this devastating pest of soft-skinned fruits. Here, we report outcomes of choice and no-choice laboratory bioassays quantifying the rates of spotted wing drosophila alightment on 5-cm-diameter sticky disks of various colors, but no fruit odors. Red, purple, and black disks captured the most spotted wing drosophila when presented against a white background. Male and female spotted wing drosophila responded identically in these tests. Significantly more D. suzukii were captured on the red and yellow disks than those presenting the corresponding grayscale for that color, proving that D. suzukii perceives colors and not just the level of target brightness. Fluorescent red is the best candidate for trap color, while clear and white are the least desirable. However, when the background was switched to black, all nonfluorescent colors were equally acceptable to spotted wing drosophila, suggesting that background must be specified when reporting spotted wing drosophila color preference. Additional spotted wing drosophila research is justified on the effects of target color against natural backgrounds. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America.

Parasite-specific immune response in adult Drosophila melanogaster: a genomic study

PubMed Central

Roxström-Lindquist, Katarina; Terenius, Olle; Faye, Ingrid

2004-01-01

Insects of the order Diptera are vectors for parasitic diseases such as malaria, sleeping sickness and leishmania. In the search for genes encoding proteins involved in the antiparasitic response, we have used the protozoan parasite Octosporea muscaedomesticae for oral infections of adult Drosophila melanogaster. To identify parasite-specific response molecules, other flies were exposed to virus, bacteria or fungi in parallel. Analysis of gene expression patterns after 24 h of microbial challenge, using Affymetrix oligonucleotide microarrays, revealed a high degree of microbe specificity. Many serine proteases, key intermediates in the induction of insect immune responses, were uniquely expressed following infection of the different organisms. Several lysozyme genes were induced in response to Octosporea infection, while in other treatments they were not induced or downregulated. This suggests that lysozymes are important in antiparasitic defence. PMID:14749722

Vibrational Detection of Odorant Functional Groups by Drosophila melanogaster

PubMed Central

Maniati, Klio; Haralambous, Katherine-Joanne

2017-01-01

Abstract A remarkable feature of olfaction, and perhaps the hardest one to explain by shape-based molecular recognition, is the ability to detect the presence of functional groups in odorants, irrespective of molecular context. We previously showed that Drosophila trained to avoid deuterated odorants could respond to a molecule bearing a nitrile group, which shares the vibrational stretch frequency with the CD bond. Here, we reproduce and extend this finding by showing analogous olfactory responses of Drosophila to the chemically vastly different functional groups, thiols and boranes, that nevertheless possess a common vibration at 2600 cm−1. Furthermore, we show that Drosophila do not respond to a cyanohydrin structure that renders nitrile groups invisible to IR spectroscopy. We argue that the response of Drosophila to these odorants which parallels their perception in humans, supports the hypothesis that odor character is encoded in odorant molecular vibrations, not in the specific shape-based activation pattern of receptors. PMID:29094064

The developmental transcriptome of Drosophila melanogaster

DOE Office of Scientific and Technical Information (OSTI.GOV)

University of Connecticut; Graveley, Brenton R.; Brooks, Angela N.

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

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

PubMed

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.

PubMed

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.

First foreign exploration for asian parasitoids of Drosophila suzukii

USDA-ARS?s Scientific Manuscript database

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 ...

Genomic Signatures of Speciation in Sympatric and Allopatric Hawaiian Picture-Winged Drosophila

PubMed Central

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

2016-01-01

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. PMID:27189993

Optogenetic pacing in Drosophila melanogaster

PubMed Central

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

2015-01-01

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

Drosophila: Retrotransposons Making up Telomeres.

PubMed

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.

Differential Contributions of Olfactory Receptor Neurons in a Drosophila Olfactory Circuit

PubMed Central

Newquist, Gunnar; Novenschi, Alexandra; Kohler, Donovan

2016-01-01

Abstract The ability of an animal to detect, discriminate, and respond to odors depends on the functions of its olfactory receptor neurons (ORNs). The extent to which each ORN, upon activation, contributes to chemotaxis is not well understood. We hypothesized that strong activation of each ORN elicits a different behavioral response in the Drosophila melanogaster larva by differentially affecting the composition of its navigational behavior. To test this hypothesis, we exposed Drosophila larvae to specific odorants to analyze the effect of individual ORN activity on chemotaxis. We used two different behavioral paradigms to analyze the chemotaxis response of larvae to odorants. When tested with five different odorants that elicit strong physiological responses from single ORNs, larval behavioral responses toward each odorant differed in the strength of attraction as well as in the composition of discrete navigational elements, such as runs and turns. Further, behavioral responses to odorants did not correlate with either the strength of odor gradients tested or the sensitivity of each ORN to its cognate odorant. Finally, we provide evidence that wild-type larvae with all ORNs intact exhibit higher behavioral variance than mutant larvae that have only a single pair of functional ORNs. We conclude that individual ORNs contribute differently to the olfactory circuit that instructs chemotactic responses. Our results, along with recent studies from other groups, suggest that ORNs are functionally nonequivalent units. These results have implications for understanding peripheral odor coding. PMID:27570823

Pharmacological identification of cholinergic receptor subtypes on Drosophila melanogaster larval heart.

PubMed

Malloy, Cole A; Ritter, Kyle; Robinson, Jonathan; English, Connor; Cooper, Robin L

2016-01-01

The Drosophila melanogaster heart is a popular model in which to study cardiac physiology and development. Progress has been made in understanding the role of endogenous compounds in regulating cardiac function in this model. It is well characterized that common neurotransmitters act on many peripheral and non-neuronal tissues as they flow through the hemolymph of insects. Many of these neuromodulators, including acetylcholine (ACh), have been shown to act directly on the D. melanogaster larval heart. ACh is a primary neurotransmitter in the central nervous system (CNS) of vertebrates and at the neuromuscular junctions on skeletal and cardiac tissue. In insects, ACh is the primary excitatory neurotransmitter of sensory neurons and is also prominent in the CNS. A full understanding regarding the regulation of the Drosophila cardiac physiology by the cholinergic system remains poorly understood. Here we use semi-intact D. melanogaster larvae to study the pharmacological profile of cholinergic receptor subtypes, nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs), in modulating heart rate (HR). Cholinergic receptor agonists, nicotine and muscarine both increase HR, while nAChR agonist clothianidin exhibits no significant effect when exposed to an open preparation at concentrations as low as 100 nM. In addition, both nAChR and mAChR antagonists increase HR as well but also display capabilities of blocking agonist actions. These results provide evidence that both of these receptor subtypes display functional significance in regulating the larval heart's pacemaker activity.

Drosophila Females Undergo Genome Expansion after Interspecific Hybridization

PubMed Central

Romero-Soriano, Valèria; Burlet, Nelly; Vela, Doris; Fontdevila, Antonio; Vieira, Cristina; García Guerreiro, María Pilar

2016-01-01

Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent. PMID:26872773

A genomic investigation of ecological differentiation between free-living and Drosophila-associated bacteria.

PubMed

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.

Single Nucleotide Polymorphism Markers for Genetic Mapping in Drosophila melanogaster

PubMed Central

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 span the genome. Most of these markers are single nucleotide polymorphisms and sequences for these variants are provided in an accessible format. The average density of the new markers is one per 225 kb on the autosomes and one per megabase on the X chromosome. We include in this survey a set of P-element strains that provide additional use for high-resolution mapping. We show one application of the new markers in a simple set of crosses to map a mutation in the hedgehog gene to an interval of <1 Mb. This new map resource significantly increases the efficiency and resolution of recombination mapping and will be of immediate value to the Drosophila research community. PMID:11381036

Single nucleotide polymorphism markers for genetic mapping in Drosophila melanogaster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoskins, Roger A.; Phan, Alexander C.; Naeemuddin, Mohammed

2001-04-16

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

Drosophila melanogaster--the model organism of choice for the complex biology of multi-cellular organisms

NASA Technical Reports Server (NTRS)

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.

Effect of the gene transformer of Anastrepha on the somatic sexual development of Drosophila.

PubMed

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.

Fruiting bodies of the social amoeba Dictyostelium discoideum increase spore transport by Drosophila

PubMed Central

2014-01-01

Background Many microbial phenotypes are the product of cooperative interactions among cells, but their putative fitness benefits are often not well understood. In the cellular slime mold Dictyostelium discoideum, unicellular amoebae aggregate when starved and form multicellular fruiting bodies in which stress-resistant spores are held aloft by dead stalk cells. Fruiting bodies are thought to be adaptations for dispersing spores to new feeding sites, but this has not been directly tested. Here we experimentally test whether fruiting bodies increase the rate at which spores are acquired by passing invertebrates. Results Drosophila melanogaster accumulate spores on their surfaces more quickly when exposed to intact fruiting bodies than when exposed to fruiting bodies physically disrupted to dislodge spore masses from stalks. Flies also ingest and excrete spores that still express a red fluorescent protein marker. Conclusions Multicellular fruiting bodies created by D. discoideum increase the likelihood that invertebrates acquire spores that can then be transported to new feeding sites. These results thus support the long-hypothesized dispersal benefits of altruism in a model system for microbial cooperation. PMID:24884856

DETERMINATION OF A BOUND MUSK XYLENE METABOLITE IN CARP HEMOGLOBIN AS A BIOMARKER OF EXPOSURE BY GAS CHROMATOGRAPHY MASS SPECTROMETRY USING SELECTED ION MONITORING

EPA Science Inventory

Musk xylene (MX) is widely used as a fragrance ingredient in commercial toiletries. Identification and quantification of a bound 4-amino-MX (AMX) metabolite was carried out by gas chromatography-mass spectrometry (GC/MS), with selected ion monitoring (SIM). Detection of AMX occur...

Is Drosophila-microbe association species-specific or region specific? A study undertaken involving six Indian Drosophila species.

PubMed

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.

Obesity-associated cardiac dysfunction in starvation-selected Drosophila melanogaster.

PubMed

Hardy, Christopher M; Birse, Ryan T; Wolf, Matthew J; Yu, Lin; Bodmer, Rolf; Gibbs, Allen G

2015-09-15

There is a clear link between obesity and cardiovascular disease, but the complexity of this interaction in mammals makes it difficult to study. Among the animal models used to investigate obesity-associated diseases, Drosophila melanogaster has emerged as an important platform of discovery. In the laboratory, Drosophila can be made obese through lipogenic diets, genetic manipulations, and adaptation to evolutionary stress. While dietary and genetic changes that cause obesity in flies have been demonstrated to induce heart dysfunction, there have been no reports investigating how obesity affects the heart in laboratory-evolved populations. Here, we studied replicated populations of Drosophila that had been selected for starvation resistance for over 65 generations. These populations evolved characteristics that closely resemble hallmarks of metabolic syndrome in mammals. We demonstrate that starvation-selected Drosophila have dilated hearts with impaired contractility. This phenotype appears to be correlated with large fat deposits along the dorsal cuticle, which alter the anatomical position of the heart. We demonstrate a strong relationship between fat storage and heart dysfunction, as dilation and reduced contractility can be rescued through prolonged fasting. Unlike other Drosophila obesity models, the starvation-selected lines do not exhibit excessive intracellular lipid deposition within the myocardium and rather store excess triglycerides in large lipid droplets within the fat body. Our findings provide a new model to investigate obesity-associated heart dysfunction. Copyright © 2015 the American Physiological Society.

big bang gene modulates gut immune tolerance in Drosophila.

PubMed

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

2013-02-19

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

Biomonitoring-based exposure assessment of benzene, toluene, ethylbenzene and xylene among workers at petroleum distribution facilities.

PubMed

Heibati, Behzad; Godri Pollitt, Krystal J; Charati, Jamshid Yazdani; Ducatman, Alan; Shokrzadeh, Mohammad; Karimi, Ali; Mohammadyan, Mahmoud

2018-03-01

Elevated emissions of volatile organic compounds, including benzene, toluene, ethylbenzene, and o, p, and m-xylenes (BTEX), are an occupational health concern at oil transfer stations. This exploratory study investigated personal exposure to BTEX through environmental air and urine samples collected from 50 male workers at a major oil distribution company in Iran. Airborne BTEX exposures were evaluated over 8h periods during work-shift by using personal passive samplers. Urinary BTEX levels were determined using solid-phase microextraction with gas chromatography mass spectrometry for separation and detection. Mean exposure to ambient concentrations of benzene differed by workers' job type: tanker loading workers (5390μg/m 3 ), tank-gauging workers (830μg/m 3 ), drivers (81.9μg/m 3 ), firefighters (71.2μg/m 3 ) and office workers (19.8μg/m 3 ). Exposure across job type was similarly stratified across all personal exposures to BTEX measured in air samples with maximum concentrations found for tanker loading workers. Average exposures concentrations of BTEX measured in urine were 11.83 ppb benzene, 1.87 ppb toluene, 0.43 ppb ethylebenzene, and 3.76 ppb xylene. Personal air exposure to benzene was found to be positively associated with benzene concentrations measured in urine; however, a relationship was not observed to the other BTEX compounds. Urinary exposure profiles are a potentially useful, noninvasive, and rapid method for assessing exposure to benzene in a developing and relatively remote production region. Copyright © 2017 Elsevier Inc. All rights reserved.

Label-free in vivo imaging of Drosophila melanogaster by multiphoton microscopy

NASA Astrophysics Data System (ADS)

Lin, Chiao-Ying; Hovhannisyan, Vladimir; Wu, June-Tai; Lin, Sung-Jan; Lin, Chii-Wann; Chen, Jyh-Horng; Dong, Chen-Yuan

2008-02-01

The fruit fly Drosophila melanogaster is one of the most valuable organisms in genetic and developmental biology studies. Drosophila is a small organism with a short life cycle, and is inexpensive and easy to maintain. The entire genome of Drosophila has recently been sequenced (cite the reference). These advantages make fruit fly an attractive model organism for biomedical researches. Unlike humans, Drosophila can be subjected to genetic manipulation with relative ease. Originally, Drosophila was mostly used in classical genetics studies. In the model era of molecular biology, the fruit fly has become a model organ for developmental biology researches. In the past, numerous molecularly modified mutants with well defined genetic defects affecting different aspects of the developmental processes have been identified and studied. However, traditionally, the developmental defects of the mutant flies are mostly examined in isolated fixed tissues which preclude the observation of the dynamic interaction of the different cell types and the extracellular matrix. Therefore, the ability to image different organelles of the fruit fly without extrinsic labeling is invaluable for Drosophila biology. In this work, we successfully acquire in vivo images of both developing muscles and axons of motor neurons in the three larval stages by using the minimially invasive imaging modality of multiphoton (SHG) microscopy. We found that while SHG imaging is useful in revealing the muscular architecture of the developing larva, it is the autofluorescence signal that allows label-free imaging of various organelles to be achieved. Our results demonstrate that multiphoton imaging is a powerful technique for investigation the development of Drosophila.

The circadian clock network in the brain of different Drosophila species.

PubMed

Hermann, Christiane; Saccon, Rachele; Senthilan, Pingkalai R; Domnik, Lilith; Dircksen, Heinrich; Yoshii, Taishi; Helfrich-Förster, Charlotte

2013-02-01

Comparative studies on cellular and molecular clock mechanisms have revealed striking similarities in the organization of the clocks among different animal groups. To gain evolutionary insight into the properties of the clock network within the Drosophila genus, we analyzed sequence identities and similarities of clock protein homologues and immunostained brains of 10 different Drosophila species using antibodies against vrille (VRI), PAR-protein domain1 (PDP1), and cryptochrome (CRY). We found that the clock network of both subgenera Sophophora and Drosophila consists of all lateral and dorsal clock neuron clusters that were previously described in Drosophila melanogaster. Immunostaining against CRY and the neuropeptide pigment-dispersing factor (PDF), however, revealed species-specific differences. All species of the Drosophila subgenus and D. pseudoobscura of the Sophophora subgenus completely lacked CRY in the large ventrolateral clock neurons (lLN(v) s) and showed reduced PDF immunostaining in the small ventrolateral clock neurons (sLN(v) s). In contrast, we found the expression of the ion transport peptide (ITP) to be consistent within the fifth sLN(v) and one dorsolateral clock neuron (LN(d) ) in all investigated species, suggesting a conserved putative function of this neuropeptide in the clock. We conclude that the general anatomy of the clock network is highly conserved throughout the Drosophila genus, although there is variation in PDF and CRY expression. Our comparative study is a first step toward understanding the organization of the circadian clock in Drosophila species adapted to different habitats. Copyright © 2012 Wiley Periodicals, Inc.

Seasonal and regional presence of hymenopteran parasitoids of Drosophila in Switzerland and their ability to parasitize the invasive Drosophila suzukii

PubMed Central

Knoll, Valery; Ellenbroek, Thomas; Romeis, Jörg; Collatz, Jana

2017-01-01

Since its introduction into Europe the invasive Drosophila suzukii has established and spread widely, thereby entering habitats populated by native Drosophila species and their natural enemies. The highly prolific D. suzukii will likely interact with these species as a competitor, host or prey. To investigate potential interactions of D. suzukii with parasitoids, a field survey was conducted across several fruit-growing regions in Switzerland in two consecutive years. Eight species of hymenopteran parasitoids were collected using D. melanogaster as sentinel hosts in field-traps. Parasitoid capture was much higher in 2015 than in 2014 and varied among regions, time of the growing season, and habitat type. Laboratory no-choice assays with the field-collected species demonstrated that the larval parasitoids Asobara tabida, Leptopilina boulardi, and L. heterotoma could not use D. suzukii for reproduction, although the latter two reduced the number of emerging D. suzukii. In contrast, the pupal parasitoids Pachycrepoideus vindemmiae, Trichopria drosophilae, Vrestovia fidenas and Spalangia erythromera all developed with D. suzukii as hosts. Regional differences between strains were generally not evident, with the exception of two T. drosophilae strains that differed in parasitization rate. Thus, native parasitoids may interact with D. suzukii and should be regarded when implementing pest control measures. PMID:28098183

Fat body remodeling and homeostasis control in Drosophila.

PubMed

Zheng, Huimei; Yang, Xiaohang; Xi, Yongmei

2016-12-15

Remarkable advances have been made in recent years in our understanding of the Drosophila fat body and its functions in energy storage, immune response and nutrient sensing. The fat body interplays with other tissues to respond to the physiological needs of the body's growth and coordinates various metabolic processes at different developmental stages and under different environmental conditions. The identification of various conserved genetic functions and signaling pathways relating to the Drosophila fat body may provide clues to lipometabolic disease and other aspects of tissue remodeling in humans. Here, we discuss recent insights into how regulation of fat body remodeling contributes to hemostasis with a special focus on how signaling networks and internal physiological states shape different aspects of the lipid metabolism in Drosophila. Copyright © 2016. Published by Elsevier Inc.

In vitro cell culture, platelet adhesion tests and in vivo implant tests of plasma-polymerized para-xylene films

NASA Astrophysics Data System (ADS)

Chou, Chia-Man; Yeh, Chou-Ming; Chung, Chi-Jen; He, Ju-Liang

2013-09-01

Plasma-polymerized para-xylene (PPX) was developed in a previous study by adjusting the process parameters: pulse frequency of the power supply (ωp) and para-xylene monomer flow rate (fp). All the obtained PPX films exhibit an amorphous structure and present hydrophobicity (water contact angle ranging from 98.5° to 121.1°), higher film growth rate and good fibroblast cell proliferation. In this study, in vitro tests (fibroblast cell compatibility and platelet adhesion) and an in vivo animal study were performed by using PPX deposited industrial-grade silicone sheets (IGS) and compared with medical-grade silicone ones (MS), which were commonly manufactured into catheters or drainage tubes in clinical use. The results reveal that PPX deposited at high ωp or high fp, in comparison with MS, exhibit better cell proliferation and clearly shows less cell adhesion regardless of ωp and fp. PPX also exhibit a comparatively lower level of platelet adhesion than MS. In the animal study, PPX-coated IGS result in similar local tissue responses at 3, 7 and 28 days (short-term) and 84 days (long-term) after subcutaneous implantation the abdominal wall of rodents compared with respective responses to MS. These results suggest that PPX-coated industrial-grade silicone is one alternative to high cost medical-grade silicone.

[The effect of altered oxygen partial pressure on the resisitance to hypoxia and expression of oxygen-sensitive genes in Drosophila melanogaster].

PubMed

Berezovs'kyĭ, V Ia; Chaka, O H; Litovka, I H; Levashov, M I; Ianko, R V

2014-01-01

As a result of resistance test to hypoxia of Drosophilas melanogaster of Oregon strain, we identified a high resistance (Group II) and low resistance (Group III) subpopulations of flies. Flies from groups II and III were incubated in a constant normobaric hypoxia (Po2=62-64 mm Hg) for 10 generations. A highly resistant group (Group IV) were exposed to a shortterm anoxia (Po,=1,5 mm Hg, 5 min) every generation. Larvae from Groups II, III, and IV demonstrated significantly elevated levels of Sir and CG 14740 expression. Larvae from Group II had a significantly higher expression of CG 14740 compared to group III. The restitution time after exposure to anoxia was significantly reduced in Group II (on 31% of the control values) Our results suggest that long-term adaptation to low oxygen partial pressure of highly resistant Drosophila significantly reduces the time of restitution and increases the expression of Sir2 and CG14740 genes.

Heat shock protein-70 (Hsp-70) suppresses paraquat-induced neurodegeneration by inhibiting JNK and caspase-3 activation in Drosophila model of Parkinson's disease.

PubMed

Shukla, Arvind Kumar; Pragya, Prakash; Chaouhan, Hitesh Singh; Tiwari, Anand Krishna; Patel, Devendra Kumar; Abdin, Malik Zainul; Chowdhuri, Debapratim Kar

2014-01-01

Parkinson's disease (PD) is one of the most common neurodegenerative disorders with limited clinical interventions. A number of epidemiological as well as case-control studies have revealed an association between pesticide exposure, especially of paraquat (PQ) and occurrence of PD. Hsp70, a molecular chaperone by function, has been shown as one of the modulators of neurological disorders. However, paucity of information regarding the protective role of Hsp70 on PQ-induced PD like symptoms led us to hypothesize that modulation of hsp70 expression in the dopaminergic neurons would improve the health of these cells. We took advantage of Drosophila, which is a well-established model for neurological research and also possesses genetic tools for easy manipulation of gene expression with limited ethical concern. Over-expression of hsp70 was found to reduce PQ-induced oxidative stress along with JNK and caspase-3 mediated dopaminergic neuronal cell death in exposed organism. Further, anti-apoptotic effect of hsp70 was shown to confer better homeostasis in the dopaminergic neurons of PQ-exposed organism as evidenced by their improved locomotor performance and survival. The study has merit in the context of human concern since we observed protection of dopaminergic neurons in PQ-exposed organism by over-expressing a human homologue of hsp70, HSPA1L, in these cells. The effect was parallel to that observed with Drosophila hsp70. These findings reflect the potential therapeutic applicability of hsp70 against PQ-induced PD like symptoms in an organism.

A comparative study to evaluate liquid dish washing soap as an alternative to xylene and alcohol in deparaffinization and hematoxylin and eosin staining

PubMed Central

Pandey, Pinki; Dixit, Alok; Tanwar, Aparna; Sharma, Anuradha; Mittal, Sanjeev

2014-01-01

Introduction: Our study presents a new deparaffinizing and hematoxylin and eosin (H and E) staining method that involves the use of easily available, nontoxic and eco-friendly liquid diluted dish washing soap (DWS) by completely eliminating expensive and hazardous xylene and alcohol from deparaffinizing and rehydration prior to staining, staining and from dehydration prior to mounting. The aim was to evaluate and compare the quality of liquid DWS treated xylene and alcohol free (XAF) sections with that of the conventional H and E sections. Materials and Methods: A total of 100 paraffin embedded tissue blocks from different tissues were included. From each tissue block, one section was stained with conventional H and E (normal sections) and the other with XAF H and E (soapy sections) staining method. Slides were scored using five parameters: Nuclear, cytoplasmic, clarity, uniformity, and crispness of staining. Z-test was used for statistical analysis. Results: Soapy sections scored better for cytoplasmic (90%) and crisp staining (95%) with a statistically significant difference. Whereas for uniformity of staining, normal sections (88%) scored over soapy sections (72%) (Z = 2.82, P < 0.05). For nuclear (90%) and clarity of staining (90%) total scored favored soapy sections, but the difference was not statistically significant. About 84% normal sections stained adequately for diagnosis when compared with 86% in soapy sections (Z = 0.396, P > 0.05). Conclusion: Liquid DWS is a safe and efficient alternative to xylene and alcohol in deparaffinization and routine H and E staining procedure. We are documenting this project that can be used as a model for other histology laboratories. PMID:25328332

Strawberry Accessions with Reduced Drosophila suzukii Emergence From Fruits

PubMed Central

Gong, Xiaoyun; Bräcker, Lasse; Bölke, Nadine; Plata, Camila; Zeitlmayr, Sarah; Metzler, Dirk; Olbricht, Klaus; Gompel, Nicolas; Parniske, Martin

2016-01-01

Drosophila suzukii is threatening soft fruit production worldwide due to the females’ ability to pierce through the intact skin of ripe fruits and lay eggs inside. Larval consumption and the associated microbial infection cause rapid fruit degradation, thus drastic yield and economic loss. Cultivars that limit the proliferation of flies may be ideal to counter this pest; however, they have not yet been developed or identified. To search for potential breeding material, we investigated the rate of adult D. suzukii emergence from individual fruits (fly emergence) of 107 accessions of Fragaria species that had been exposed to egg-laying D. suzukii females. We found significant variation in fly emergence across strawberries, which correlated with accession and fruit diameter, and to a lesser extent with the strawberry species background. We identified accessions with significantly reduced fly emergence, not explained by their fruit diameter. These accessions constitute valuable breeding material for strawberry cultivars that limit D. suzukii spread. PMID:28066452

Differential sexual survival of Drosophila melanogaster on copper sulfate.

PubMed

Balinski, Michael A; Woodruff, Ronny C

2017-04-01

Based on studies of the influence of X-chromosomes on the viability of Drosophila melanogaster exposed to cadmium, and on the role of X-linked genes on copper homeostasis, we examined the effect of copper sulfate (CuSO 4 ) on offspring viability using three independent, inbred D. melanogaster crosses (ensuring identical autosomes for males and females within each cross). Each cross was performed with attached X-chromosome females and males with a single X-chromosome. As female D. melanogaster have less metallothionein RNA expression than males, we predicted fewer female offspring than male offspring in crosses exposed to CuSO 4 , even though females have two copies of X-chromosome genes, possibly resulting in overdominant heterozygosity. In two of three crosses, CuSO 4 caused significantly higher numbers of male offspring compared to female offspring. We hypothesized that these gender-based viability differences to copper exposure are caused by X-chromosome ploidy and X-linked genetic variation affecting metallothionein expression. Observed differential offspring viability responses among crosses to copper exposure also showed that different genetic backgrounds (autosomal and/or X-chromosome) can result in significant differences in heavy metal and metallothionein regulation. These results suggest that the effect of copper on offspring viability depends on both genetic background and gender, as both factors can affect the regulation of metallothionein proteins as well as homeostasis of biologically necessary heavy metals.

The epicurean fly: using Drosophila melanogaster to study metabolism.

PubMed

Bharucha, Kamal N

2009-02-01

In this review, the utility of Drosophila melanogaster as a model organism for research in metabolism will be demonstrated. Importantly, many metabolic pathways are conserved in both man and the fly. Recent work has highlighted that these conserved molecular pathways have the potential to give rise to similar phenotypes. For example, it has proven possible to generate obese and diabetic Drosophila; conversely, genetic manipulation can also generate lean and hypoglycemic phenotypes. From conserved circulating hormones to key enzymes, the fly is host to a variety of homologous, metabolically active signaling mechanisms. The world of Drosophila research has not only a rich history of developing techniques for exquisite genetic manipulation, but also continues to develop genetic methodologies at an exciting rate. Many of these techniques add to the cadre of experimental tools available for the use of the fly as a model organism for studying carbohydrate and lipid homeostasis. This review is written for the pediatric-scientist with little background in Drosophila, with the goal of relaying the potential of this model organism for contributing to a better understanding of diseases affecting today's children.

Embryonic multipotent progenitors remodel the Drosophila airways during metamorphosis

PubMed Central

Pitsouli, Chrysoula; Perrimon, Norbert

2010-01-01

Adult structures in holometabolous insects such as Drosophila are generated by groups of imaginal cells dedicated to the formation of different organs. Imaginal cells are specified in the embryo and remain quiescent until the larval stages, when they proliferate and differentiate to form organs. The Drosophila tracheal system is extensively remodeled during metamorphosis by a small number of airway progenitors. Among these, the spiracular branch tracheoblasts are responsible for the generation of the pupal and adult abdominal airways. To understand the coordination of proliferation and differentiation during organogenesis of tubular organs, we analyzed the remodeling of Drosophila airways during metamorphosis. We show that the embryonic spiracular branch tracheoblasts are multipotent cells that express the homeobox transcription factor Cut, which is necessary for their survival and normal development. They give rise to three distinct cell populations at the end of larval development, which generate the adult tracheal tubes, the spiracle and the epidermis surrounding the spiracle. Our study establishes the series of events that lead to the formation of an adult tubular structure in Drosophila. PMID:20940225

Genomic Signatures of Speciation in Sympatric and Allopatric Hawaiian Picture-Winged Drosophila.

PubMed

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.

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

PubMed

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.

Drosophila hematopoiesis under normal conditions and in response to immune stress.

PubMed

Letourneau, Manon; Lapraz, Francois; Sharma, Anurag; Vanzo, Nathalie; Waltzer, Lucas; Crozatier, Michèle

2016-11-01

The emergence of hematopoietic progenitors and their differentiation into various highly specialized blood cell types constitute a finely tuned process. Unveiling the genetic cascades that control blood cell progenitor fate and understanding how they are modulated in response to environmental changes are two major challenges in the field of hematopoiesis. In the last 20 years, many studies have established important functional analogies between blood cell development in vertebrates and in the fruit fly, Drosophila melanogaster. Thereby, Drosophila has emerged as a powerful genetic model for studying mechanisms that control hematopoiesis during normal development or in pathological situations. Moreover, recent advances in Drosophila have highlighted how intricate cell communication networks and microenvironmental cues regulate blood cell homeostasis. They have also revealed the striking plasticity of Drosophila mature blood cells and the presence of different sites of hematopoiesis in the larva. This review provides an overview of Drosophila hematopoiesis during development and summarizes our current knowledge on the molecular processes controlling larval hematopoiesis, both under normal conditions and in response to an immune challenge, such as wasp parasitism. © 2016 Federation of European Biochemical Societies.

CROSS-RESISTANCE FOLLOWING ARTIFICIAL SELECTION FOR INCREASED DEFENSE AGAINST PARASITOIDS IN DROSOPHILA MELANOGASTER.

PubMed

Fellowes, M D E; Kraaijeveld, A R; Godfray, H C J

1999-06-01

An increase in resistance to one natural enemy may result in no correlated change, a positive correlated change, or a negative correlated change in the ability of the host or prey to resist other natural enemies. The type of specificity is important in understanding the evolutionary response to natural enemies and was studied here in a Drosophila-paxasitoid system. Drosophila melanogaster lines selected for increased larval resistance to the endoparasitoid wasps Asobara tabida or Leptopilina boulardi were exposed to attack by A. tabida, L. boulardi and Leptopilina heterotoma at 15°C, 20°C, and 25°C. In general, encapsulation ability increased with temperature, with the exception of the lines selected against L. boulardi, which showed the opposite trend. Lines selected against L. boulardi showed large increases in resistance against all three parasitoid species, and showed similar levels of defense against A. tabida to the lines selected against that parasitoid. In contrast, lines selected against A. tabida showed a large increase in resistance to A. tabida and generally to L. heterotoma, but displayed only a small change in their ability to survive attack by L. boulardi. Such asymmetries in correlated responses to selection for increased resistance to natural enemies may influence host-parasitoid community structure. © 1999 The Society for the Study of Evolution.

Drosophila lacks C20 and C22 polyunsaturated fatty acids

USDA-ARS?s Scientific Manuscript database

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

Thermotaxis, circadian rhythms, and TRP channels in Drosophila

PubMed Central

Bellemer, Andrew

2015-01-01

The fruit fly Drosophila melanogaster is a poikilothermic organism that must detect and respond to both fine and coarse changes in environmental temperature in order maintain optimal body temperature, synchronize behavior to daily temperature fluctuations, and to avoid potentially injurious environmental hazards. Members of the Transient Receptor Potential (TRP) family of cation channels are well known for their activation by changes in temperature and their essential roles in sensory transduction in both invertebrates and vertebrates. The Drosophila genome encodes 13 TRP channels, and several of these have key sensory transduction and modulatory functions in allowing larval and adult flies to make fine temperature discriminations to attain optimal body temperature, detect and avoid large environmental temperature fluctuations, and make rapid escape responses to acutely noxious stimuli. Drosophila use multiple, redundant signaling pathways and neural circuits to execute these behaviors in response to both increases and decreases in temperature of varying magnitudes and time scales. A plethora of powerful molecular and genetic tools and the fly's simple, well-characterized nervous system have given Drosophila neurobiologists a powerful platform to study the cellular and molecular mechanisms of TRP channel function and how these mechanisms are conserved in vertebrates, as well as how these channels function within sensorimotor circuits to generate both simple and complex thermosensory behaviors. PMID:27227026

'Peer pressure' in larval Drosophila?

PubMed

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

2014-06-06

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

Evolution of Drosophila ribosomal protein gene core promoters.

PubMed

Ma, Xiaotu; Zhang, Kangyu; Li, Xiaoman

2009-03-01

The coordinated expression of ribosomal protein genes (RPGs) has been well documented in many species. Previous analyses of RPG promoters focus only on Fungi and mammals. Recognizing this gap and using a comparative genomics approach, we utilize a motif-finding algorithm that incorporates cross-species conservation to identify several significant motifs in Drosophila RPG promoters. As a result, significant differences of the enriched motifs in RPG promoter are found among Drosophila, Fungi, and mammals, demonstrating the evolutionary dynamics of the ribosomal gene regulatory network. We also report a motif present in similar numbers of RPGs among Drosophila species which does not appear to be conserved at the individual RPG gene level. A module-wise stabilizing selection theory is proposed to explain this observation. Overall, our results provide significant insight into the fast-evolving nature of transcriptional regulation in the RPG module.

Evolution of Drosophila ribosomal protein gene core promoters

PubMed Central

Ma, Xiaotu; Zhang, Kangyu; Li, Xiaoman

2011-01-01

The coordinated expression of ribosomal protein genes (RPGs) has been well documented in many species. Previous analyses of RPG promoters focus only on Fungi and mammals. Recognizing this gap and using a comparative genomics approach, we utilize a motif-finding algorithm that incorporates cross-species conservation to identify several significant motifs in Drosophila RPG promoters. As a result, significant differences of the enriched motifs in RPG promoter are found among Drosophila, Fungi, and mammals, demonstrating the evolutionary dynamics of the ribosomal gene regulatory network. We also report a motif present in similar numbers of RPGs among Drosophila species which does not appear to be conserved at the individual RPG gene level. A module-wise stabilizing selection theory is proposed to explain this observation. Overall, our results provide significant insight into the fast-evolving nature of transcriptional regulation in the RPG module. PMID:19059316

Genetic manipulation and monitoring of autophagy in Drosophila.

PubMed

Neufeld, Thomas P

2008-01-01

Drosophila melanogaster provides a model system useful for many aspects of the study of autophagy in vivo. These include testing and validation of genes potentially involved in autophagy, discovery of novel genes through genetic screening for mutations that affect autophagy, and analysis of potential roles of autophagy in specific developmental or physiological processes. In recent years, a number of techniques and transgenic and mutant fly strains have been developed to facilitate autophagy analysis in this system. Here, protocols are described for activating or inhibiting autophagy in Drosophila, and for examining the progression of autophagy in vivo through imaging-based assays. The goal of this chapter is to provide a resource both for autophagy investigators with limited familiarity with fly genetics, as well as for experienced Drosophila biologists who wish to test for connections between autophagy and a given gene, pathway or process.

Functional reconstitution of Drosophila melanogaster NMJ glutamate receptors

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Functional reconstitution of Drosophila melanogaster NMJ glutamate receptors

DOE PAGES

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

2015-04-27

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

Piwi Nuclear Localization and Its Regulatory Mechanism in Drosophila Ovarian Somatic Cells.

PubMed

Yashiro, Ryu; Murota, Yukiko; Nishida, Kazumichi M; Yamashiro, Haruna; Fujii, Kaede; Ogai, Asuka; Yamanaka, Soichiro; Negishi, Lumi; Siomi, Haruhiko; Siomi, Mikiko C

2018-06-19

In Drosophila ovarian somatic cells (OSCs), Piwi represses transposons transcriptionally to maintain genome integrity. Piwi nuclear localization requires the N terminus and PIWI-interacting RNA (piRNA) loading of Piwi. However, the underlying mechanism remains unknown. Here, we show that Importinα (Impα) plays a pivotal role in Piwi nuclear localization and that Piwi has a bipartite nuclear localization signal (NLS). Impα2 and Impα3 are highly expressed in OSCs, whereas Impα1 is the least expressed. Loss of Impα2 or Impα3 forces Piwi to be cytoplasmic, which is rectified by overexpression of any Impα members. Extension of Piwi-NLS with an additional Piwi-NLS leads Piwi to be imported to the nucleus in a piRNA-independent manner, whereas replacement of Piwi-NLS with SV40-NLS fails. Limited proteolysis analysis suggests that piRNA loading onto Piwi triggers conformational change, exposing the N terminus to the environment. These results suggest that Piwi autoregulates its nuclear localization by exposing the NLS to Impα upon piRNA loading. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

The genetic basis of Haldane's rule and the nature of asymmetric hybrid male sterility among Drosophila simulans, Drosophila mauritiana and Drosophila sechellia.

PubMed

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.

The Genetic Basis of Haldane's Rule and the Nature of Asymmetric Hybrid Male Sterility among Drosophila Simulans, Drosophila Mauritiana and Drosophila Sechellia

PubMed Central

Zeng, L. W.; Singh, R. S.

1993-01-01

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. PMID:8514134

Starvation-Induced Dietary Behaviour in Drosophila melanogaster Larvae and Adults

PubMed Central

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

2015-01-01

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. PMID:26399327

Immune genes and divergent antimicrobial peptides in flies of the subgenus Drosophila.

PubMed

Hanson, Mark A; Hamilton, Phineas T; Perlman, Steve J

2016-10-24

Drosophila is an important model for studying the evolution of animal immunity, due to the powerful genetic tools developed for D. melanogaster. However, Drosophila is an incredibly speciose lineage with a wide range of ecologies, natural histories, and diverse natural enemies. Surprisingly little functional work has been done on immune systems of species other than D. melanogaster. In this study, we examine the evolution of immune genes in the speciose subgenus Drosophila, which diverged from the subgenus Sophophora (that includes D. melanogaster) approximately 25-40 Mya. We focus on D. neotestacea, a woodland species used to study interactions between insects and parasitic nematodes, and combine recent transcriptomic data with infection experiments to elucidate aspects of host immunity. We found that the vast majority of genes involved in the D. melanogaster immune response are conserved in D. neotestacea, with a few interesting exceptions, particularly in antimicrobial peptides (AMPs); until recently, AMPs were not thought to evolve rapidly in Drosophila. Unexpectedly, we found a distinct diptericin in subgenus Drosophila flies that appears to have evolved under diversifying (positive) selection. We also describe the presence of the AMP drosocin, which was previously thought to be restricted to the subgenus Sophophora, in the subgenus Drosophila. We challenged two subgenus Drosophila species, D. neotestacea and D. virilis with bacterial and fungal pathogens and quantified AMP expression. While diptericin in D. virilis was induced by exposure to gram-negative bacteria, it was not induced in D. neotestacea, showing that conservation of immune genes does not necessarily imply conservation of the realized immune response. Our study lends support to the idea that invertebrate AMPs evolve rapidly, and that Drosophila harbor a diverse repertoire of AMPs with potentially important functional consequences.

The FLIGHT Drosophila RNAi database

PubMed Central

Bursteinas, Borisas; Jain, Ekta; Gao, Qiong; Baum, Buzz; Zvelebil, Marketa

2010-01-01

FLIGHT (http://flight.icr.ac.uk/) is an online resource compiling data from high-throughput Drosophila in vivo and in vitro RNAi screens. FLIGHT includes details of RNAi reagents and their predicted off-target effects, alongside RNAi screen hits, scores and phenotypes, including images from high-content screens. The latest release of FLIGHT is designed to enable users to upload, analyze, integrate and share their own RNAi screens. Users can perform multiple normalizations, view quality control plots, detect and assign screen hits and compare hits from multiple screens using a variety of methods including hierarchical clustering. FLIGHT integrates RNAi screen data with microarray gene expression as well as genomic annotations and genetic/physical interaction datasets to provide a single interface for RNAi screen analysis and datamining in Drosophila. PMID:20855970

Drosophila blood cells and their role in immune responses.

PubMed

Vlisidou, Isabella; Wood, Will

2015-04-01

Drosophila melanogaster has been extensively used to study the humoral arm of innate immunity because of the developmental and functional parallels with mammalian innate immunity. However, the fly cellular response to infection is far less understood. Investigative work on Drosophila haemocytes, the immunosurveillance cells of the insect, has revealed that they fulfil roles similar to mammalian monocytes and macrophages. They respond to wound signals and orchestrate the coagulation response. In addition, they phagocytose and encapsulate invading pathogens, and clear up apoptotic bodies controlling inflammation. This review briefly describes the Drosophila haematopoietic system and discusses what is currently known about the contribution of haemocytes to the immune response upon infection and wounding, during all stages of development. © 2015 FEBS.

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

USDA-ARS?s Scientific Manuscript database

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...

Drosophila as a model system to study autophagy.

PubMed

Zirin, Jonathan; Perrimon, Norbert

2010-12-01

Originally identified as a response to starvation in yeast, autophagy is now understood to fulfill a variety of roles in higher eukaryotes, from the maintenance of cellular homeostasis to the cellular response to stress, starvation, and infection. Although genetics and biochemical studies in yeast have identified many components involved in autophagy, the findings that some of the essential components of the yeast pathway are missing in higher organisms underscore the need to study autophagy in more complex systems. This review focuses on the use of the fruitfly, Drosophila melanogaster as a model system for analysis of autophagy. Drosophila is an organism well-suited for genetic analysis and represents an intermediate between yeast and mammals with respect to conservation of the autophagy machinery. Furthermore, the complex biology and physiology of Drosophila presents an opportunity to model human diseases in a tissue specific and analogous context.

Stem cells in the Drosophila digestive system.

PubMed

Zeng, Xiankun; Chauhan, Chhavi; Hou, Steven X

2013-01-01

Adult stem cells maintain tissue homeostasis by continuously replenishing damaged, aged and dead cells in any organism. Five types of region and organ-specific multipotent adult stem cells have been identified in the Drosophila digestive system: intestinal stem cells (ISCs) in the posterior midgut; hindgut intestinal stem cells (HISCs) at the midgut/hindgut junction; renal and nephric stem cells (RNSCs) in the Malpighian Tubules; type I gastric stem cells (GaSCs) at foregut/midgut junction; and type II gastric stem cells (GSSCs) at the middle of the midgut. Despite the fact that each type of stem cell is unique to a particular organ, they share common molecular markers and some regulatory signaling pathways. Due to the simpler tissue structure, ease of performing genetic analysis, and availability of abundant mutants, Drosophila serves as an elegant and powerful model system to study complex stem cell biology. The recent discoveries, particularly in the Drosophila ISC system, have greatly advanced our understanding of stem cell self-renewal, differentiation, and the role of stem cells play in tissue homeostasis/regeneration and adaptive tissue growth.

Cold hardiness of winter-acclimated Drosophila suzukii (Diptera: Drosophilidae) adults

Treesearch

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...

Molecular genetic analysis of circadian timekeeping in Drosophila

PubMed Central

Hardin, Paul E.

2014-01-01

A genetic screen for mutants that alter circadian rhythms in Drosophila identified the first clock gene - the period (per) gene. The per gene is a central player within a transcriptional feedback loop that represents the core mechanism for keeping circadian time in Drosophila and other animals. The per feedback loop, or core loop, is interlocked with the Clock (Clk) feedback loop, but whether the Clk feedback loop contributes to circadian timekeeping is not known. A series of distinct molecular events are thought to control transcriptional feedback in the core loop. The time it takes to complete these events should take much less than 24h, thus delays must be imposed at different steps within the core loop. As new clock genes are identified, the molecular mechanisms responsible for these delays have been revealed in ever-increasing detail, and provide an in depth accounting of how transcriptional feedback loops keep circadian time. The phase of these feedback loops shift to maintain synchrony with environmental cycles, the most reliable of which is light. Although a great deal is known about cell-autonomous mechanisms of light-induced phase shifting by CRYPTOCHROME (CRY), much less is known about non-cell autonomous mechanisms. CRY mediates phase shifts through an uncharacterized mechanism in certain brain oscillator neurons, and carries out a dual role as a photoreceptor and transcription factor in other tissues. Here I will review how transcriptional feedback loops function to keep time in Drosophila, how they impose delays to maintain a 24h cycle, and how they maintain synchrony with environmental light:dark cycles. The transcriptional feedback loops that keep time in Drosophila are well conserved in other animals, thus what we learn about these loops in Drosophila should continue to provide insight into the operation of analogous transcriptional feedback loops in other animals. PMID:21924977

Circadian Modulation of Consolidated Memory Retrieval Following Sleep Deprivation in Drosophila

PubMed Central

Glou, Eric Le; Seugnet, Laurent; Shaw, Paul J.; Preat, Thomas; Goguel, Valérie

2012-01-01

Objectives: Several lines of evidence indicate that sleep plays a critical role in learning and memory. The aim of this study was to evaluate anesthesia resistant memory following sleep deprivation in Drosophila. Design: Four to 16 h after aversive olfactory training, flies were sleep deprived for 4 h. Memory was assessed 24 h after training. Training, sleep deprivation, and memory tests were performed at different times during the day to evaluate the importance of the time of day for memory formation. The role of circadian rhythms was further evaluated using circadian clock mutants. Results Memory was disrupted when flies were exposed to 4 h of sleep deprivation during the consolidation phase. Interestingly, normal memory was observed following sleep deprivation when the memory test was performed during the 2 h preceding lights-off, a period characterized by maximum wake in flies. We also show that anesthesia resistant memory was less sensitive to sleep deprivation in flies with disrupted circadian rhythms. Conclusions Our results indicate that anesthesia resistant memory, a consolidated memory less costly than long-term memory, is sensitive to sleep deprivation. In addition, we provide evidence that circadian factors influence memory vulnerability to sleep deprivation and memory retrieval. Taken together, the data show that memories weakened by sleep deprivation can be retrieved if the animals are tested at the optimal circadian time. Citation: Le Glou E; Seugnet L; Shaw PJ; Preat T; Goguel V. Circadian modulation of consolidated memory retrieval following sleep deprivation in Drosophila. SLEEP 2012;35(10):1377-1384. PMID:23024436

The Esg Gene Is Involved in Nicotine Sensitivity in Drosophila melanogaster

PubMed Central

Reyes-Taboada, José Luis; Covarrubias, Alejandra A; Narvaez-Padilla, Verónica; Reynaud, Enrique

2015-01-01

In humans, there is a strong correlation between sensitivity to substances of abuse and addiction risk. This differential tolerance to drugs has a strong genetic component. The identification of human genetic factors that alter drug tolerance has been a difficult task. For this reason and taking advantage of the fact that Drosophila responds similarly to humans to many drugs, and that genetically it has a high degree of homology (sharing at least 70% of genes known to be involved in human genetic diseases), we looked for genes in Drosophila that altered their nicotine sensitivity. We developed an instantaneous nicotine vaporization technique that exposed flies in a reproducible way. The amount of nicotine sufficient to “knock out” half of control flies for 30 minutes was determined and this parameter was defined as Half Recovery Time (HRT). Two fly lines, L4 and L70, whose HRT was significantly longer than control´s were identified. The L4 insertion is a loss of function allele of the transcriptional factor escargot (esg), whereas L70 insertion causes miss-expression of the microRNA cluster miR-310-311-312-313 (miR-310c). In this work, we demonstrate that esg loss of function induces nicotine sensitivity possibly by altering development of sensory organs and neurons in the medial section of the thoracoabdominal ganglion. The ectopic expression of the miR-310c also induces nicotine sensitivity by lowering Esg levels thus disrupting sensory organs and possibly to the modulation of other miR-310c targets. PMID:26222315

The Esg Gene Is Involved in Nicotine Sensitivity in Drosophila melanogaster.

PubMed

Sanchez-Díaz, Iván; Rosales-Bravo, Fernando; Reyes-Taboada, José Luis; Covarrubias, Alejandra A; Narvaez-Padilla, Verónica; Reynaud, Enrique

2015-01-01

In humans, there is a strong correlation between sensitivity to substances of abuse and addiction risk. This differential tolerance to drugs has a strong genetic component. The identification of human genetic factors that alter drug tolerance has been a difficult task. For this reason and taking advantage of the fact that Drosophila responds similarly to humans to many drugs, and that genetically it has a high degree of homology (sharing at least 70% of genes known to be involved in human genetic diseases), we looked for genes in Drosophila that altered their nicotine sensitivity. We developed an instantaneous nicotine vaporization technique that exposed flies in a reproducible way. The amount of nicotine sufficient to "knock out" half of control flies for 30 minutes was determined and this parameter was defined as Half Recovery Time (HRT). Two fly lines, L4 and L70, whose HRT was significantly longer than control´s were identified. The L4 insertion is a loss of function allele of the transcriptional factor escargot (esg), whereas L70 insertion causes miss-expression of the microRNA cluster miR-310-311-312-313 (miR-310c). In this work, we demonstrate that esg loss of function induces nicotine sensitivity possibly by altering development of sensory organs and neurons in the medial section of the thoracoabdominal ganglion. The ectopic expression of the miR-310c also induces nicotine sensitivity by lowering Esg levels thus disrupting sensory organs and possibly to the modulation of other miR-310c targets.

Molecular symmetry group analysis of the low-wavenumber torsions and vibration-torsions in the S1 state and ground state cation of p-xylene: An investigation using resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy

NASA Astrophysics Data System (ADS)

Gardner, Adrian M.; Tuttle, William D.; Groner, Peter; Wright, Timothy G.

2017-03-01

For the first time, a molecular symmetry group (MSG) analysis has been undertaken in the investigation of the electronic spectroscopy of p-xylene (p-dimethylbenzene). Torsional and vibration-torsional (vibtor) levels in the S1 state and ground state of the cation of p-xylene are investigated using resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy. In the present work, we concentrate on the 0-350 cm-1 region, where there are a number of torsional and vibtor bands and we discuss the assignment of this region. In Paper II [W. D. Tuttle et al., J. Chem. Phys. 146, 124309 (2017)], we examine the 350-600 cm-1 region where vibtor levels are observed as part of a Fermi resonance. The similarity of much of the observed spectral activity to that in the related substituted benzenes, toluene and para-fluorotoluene, is striking, despite the different symmetries. The discussion necessitates a consideration of the MSG of p-xylene, which has been designated G72, but we shall also designate [{3,3}]D2h and we include the symmetry operations, character table, and direct product table for this. We also discuss the symmetries of the internal rotor (torsional) levels and the selection rules for the particular electronic transition of p-xylene investigated here.

Notch and affinity boundaries in Drosophila.

PubMed

Herranz, Héctor; Milán, Marco

2006-02-01

Cells in multicellular organisms often do not intermingle freely with each other. Differential cell affinities can contribute to organizing cells into different tissues. Drosophila limbs and the vertebrate central nervous system are subdivided into compartments. Cells in adjacent compartments do not mix. Cell interactions mediated by Notch-family receptors have been implicated in the specification of these compartment boundaries. Two recent reports analyze the role of the Notch signaling pathway in the generation of an affinity boundary in the Drosophila wing. The first report analyzes the connection between Notch and the actin cytoskeleton. The second report analyzes the differential requirements of Notch and the transcription factor Suppressor of Hairless in generating the affinity boundary.

Sleep Deprivation During Early-Adult Development Results in Long-Lasting Learning Deficits in Adult Drosophila

PubMed Central

Seugnet, Laurent; Suzuki, Yasuko; Donlea, Jeff M.; Gottschalk, Laura; Shaw, Paul J.

2011-01-01

Study Objectives: Multiple lines of evidence indicate that sleep is important for the developing brain, although little is known about which cellular and molecular pathways are affected. Thus, the aim of this study was to determine whether the early adult life of Drosophila, which is associated with high amounts of sleep and critical periods of brain plasticity, could be used as a model to identify developmental processes that require sleep. Subjects: Wild type Canton-S Drosophila melanogaster. Design; Intervention: Flies were sleep deprived on their first full day of adult life and allowed to recover undisturbed for at least 3 days. The animals were then tested for short-term memory and response-inhibition using aversive phototaxis suppression (APS). Components of dopamine signaling were further evaluated using mRNA profiling, immunohistochemistry, and pharmacological treatments. Measurements and Results: Flies exposed to acute sleep deprivation on their first day of life showed impairments in short-term memory and response inhibition that persisted for at least 6 days. These impairments in adult performance were reversed by dopamine agonists, suggesting that the deficits were a consequence of reduced dopamine signaling. However, sleep deprivation did not impact dopaminergic neurons as measured by their number or by the levels of dopamine, pale (tyrosine hydroxylase), dopadecarboxylase, and the Dopamine transporter. However, dopamine pathways were impacted as measured by increased transcript levels of the dopamine receptors D2R and dDA1. Importantly, blocking signaling through the dDA1 receptor in animals that were sleep deprived during their critical developmental window prevented subsequent adult learning impairments. Conclusions: These data indicate that sleep plays an important and phylogenetically conserved role in the developing brain. Citation: Seugnet L; Suzuki Y; Donlea JM; Gottschalk L; Shaw PJ. Sleep deprivation during early-adult development results in

Stem-Cell-Based Tumorigenesis in Adult Drosophila.

PubMed

Hou, S X; Singh, S R

2017-01-01

Recent studies suggest that a small subset of cells within a tumor, the so-called cancer stem cells (CSCs), are responsible for tumor propagation, relapse, and the eventual death of most cancer patients. CSCs may derive from a few tumor-initiating cells, which are either transformed normal stem cells or reprogrammed differentiated cells after acquiring initial cancer-causing mutations. CSCs and normal stem cells share some properties, but CSCs differ from normal stem cells in their tumorigenic ability. Notably, CSCs are usually resistant to chemo- and radiation therapies. Despite the apparent roles of CSCs in human cancers, the biology underlying their behaviors remains poorly understood. Over the past few years, studies in Drosophila have significantly contributed to this new frontier of cancer research. Here, we first review how stem-cell tumors are initiated and propagated in Drosophila, through niche appropriation in the posterior midgut and through stem-cell competition for niche occupancy in the testis. We then discuss the differences between normal and tumorigenic stem cells, revealed by studying Ras V12 -transformed stem-cell tumors in the Drosophila kidney. Finally, we review the biology behind therapy resistance, which has been elucidated through studies of stem-cell resistance and sensitivity to death inducers using female germline stem cells and intestinal stem cells of the posterior midgut. We expect that screens using adult Drosophila neoplastic stem-cell tumor models will be valuable for identifying novel and effective compounds for treating human cancers. © 2017 Elsevier Inc. All rights reserved.

Selective endosomal microautophagy is starvation-inducible in Drosophila.

PubMed

Mukherjee, Anindita; Patel, Bindi; Koga, Hiroshi; Cuervo, Ana Maria; Jenny, Andreas

2016-11-01

Autophagy delivers cytosolic components to lysosomes for degradation and is thus essential for cellular homeostasis and to cope with different stressors. As such, autophagy counteracts various human diseases and its reduction leads to aging-like phenotypes. Macroautophagy (MA) can selectively degrade organelles or aggregated proteins, whereas selective degradation of single proteins has only been described for chaperone-mediated autophagy (CMA) and endosomal microautophagy (eMI). These 2 autophagic pathways are specific for proteins containing KFERQ-related targeting motifs. Using a KFERQ-tagged fluorescent biosensor, we have identified an eMI-like pathway in Drosophila melanogaster. We show that this biosensor localizes to late endosomes and lysosomes upon prolonged starvation in a KFERQ- and Hsc70-4- dependent manner. Furthermore, fly eMI requires endosomal multivesicular body formation mediated by ESCRT complex components. Importantly, induction of Drosophila eMI requires longer starvation than the induction of MA and is independent of the critical MA genes atg5, atg7, and atg12. Furthermore, inhibition of Tor signaling induces eMI in flies under nutrient rich conditions, and, as eMI in Drosophila also requires atg1 and atg13, our data suggest that these genes may have a novel, additional role in regulating eMI in flies. Overall, our data provide the first evidence for a novel, starvation-inducible, catabolic process resembling endosomal microautophagy in the Drosophila fat body.

Unraveling Selection in the Mitochondrial Genome of Drosophila

PubMed Central

Ballard, JWO.; Kreitman, M.

1994-01-01

We examine mitochondrial DNA variation at the cytochrome b locus within and between three species of Drosophila to determine whether patterns of variation conform to the predictions of neutral molecular evolution. The entire 1137-bp cytochrome b locus was sequenced in 16 lines of Drosophila melanogaster, 18 lines of Drosophila simulans and 13 lines of Drosophila yakuba. Patterns of variation depart from neutrality by several test criteria. Analysis of the evolutionary clock hypothesis shows unequal rates of change along D. simulans lineages. A comparison within and between species of the ratio of amino acid replacement change to synonymous change reveals a relative excess of amino acid replacement polymorphism compared to the neutral prediction, suggestive of slightly deleterious or diversifying selection. There is evidence for excess homozygosity in our world wide sample of D. melanogaster and D. simulans alleles, as well as a reduction in the number of segregating sites in D. simulans, indicative of selective sweeps. Furthermore, a test of neutrality for codon usage shows the direction of mutations at third positions differs among different topological regions of the gene tree. The analyses indicate that molecular variation and evolution of mtDNA are governed by many of the same selective forces that have been shown to govern nuclear genome evolution and suggest caution be taken in the use of mtDNA as a ``neutral'' molecular marker. PMID:7851772

Calcium and Egg Activation in Drosophila

PubMed Central

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

Flying Drosophila orient to sky polarization.

PubMed

Weir, Peter T; Dickinson, Michael H

2012-01-10

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

‘Peer pressure’ in larval Drosophila?

PubMed Central

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

2014-01-01

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

Experience improves feature extraction in Drosophila.

PubMed

Peng, Yueqing; Xi, Wang; Zhang, Wei; Zhang, Ke; Guo, Aike

2007-05-09

Previous exposure to a pattern in the visual scene can enhance subsequent recognition of that pattern in many species from honeybees to humans. However, whether previous experience with a visual feature of an object, such as color or shape, can also facilitate later recognition of that particular feature from multiple visual features is largely unknown. Visual feature extraction is the ability to select the key component from multiple visual features. Using a visual flight simulator, we designed a novel protocol for visual feature extraction to investigate the effects of previous experience on visual reinforcement learning in Drosophila. We found that, after conditioning with a visual feature of objects among combinatorial shape-color features, wild-type flies exhibited poor ability to extract the correct visual feature. However, the ability for visual feature extraction was greatly enhanced in flies trained previously with that visual feature alone. Moreover, we demonstrated that flies might possess the ability to extract the abstract category of "shape" but not a particular shape. Finally, this experience-dependent feature extraction is absent in flies with defective MBs, one of the central brain structures in Drosophila. Our results indicate that previous experience can enhance visual feature extraction in Drosophila and that MBs are required for this experience-dependent visual cognition.

Suboptimal evolutionary novel environments promote singular altered gravity responses of transcriptome during Drosophila metamorphosis

PubMed Central

2013-01-01

Background Previous experiments have shown that the reduced gravity aboard the International Space Station (ISS) causes important alterations in Drosophila gene expression. These changes were shown to be intimately linked to environmental space-flight related constraints. Results Here, we use an array of different techniques for ground-based simulation of microgravity effects to assess the effect of suboptimal environmental conditions on the gene expression of Drosophila in reduced gravity. A global and integrative analysis, using “gene expression dynamics inspector” (GEDI) self-organizing maps, reveals different degrees in the responses of the transcriptome when using different environmental conditions or microgravity/hypergravity simulation devices. Although the genes that are affected are different in each simulation technique, we find that the same gene ontology groups, including at least one large multigene family related with behavior, stress response or organogenesis, are over represented in each case. Conclusions These results suggest that the transcriptome as a whole can be finely tuned to gravity force. In optimum environmental conditions, the alteration of gravity has only mild effects on gene expression but when environmental conditions are far from optimal, the gene expression must be tuned greatly and effects become more robust, probably linked to the lack of experience of organisms exposed to evolutionary novel environments such as a gravitational free one. PMID:23806134

Systematic screen of chemotherapeutics in Drosophila stem cell tumors

PubMed Central

Markstein, Michele; Dettorre, Samantha; Cho, Julio; Neumüller, Ralph A.; Craig-Müller, Sören; Perrimon, Norbert

2014-01-01

Here we report the development of an in vivo system to study the interaction of stem cells with drugs using a tumor model in the adult Drosophila intestine. Strikingly, we find that some Food and Drug Administration-approved chemotherapeutics that can inhibit the growth of Drosophila tumor stem cells can paradoxically promote the hyperproliferation of their wild-type counterparts. These results reveal an unanticipated side effect on stem cells that may contribute to tumor recurrence. We propose that the same side effect may occur in humans based on our finding that it is driven in Drosophila by the evolutionarily conserved Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway. An immediate implication of our findings is that supplementing traditional chemotherapeutics with anti-inflammatories may reduce tumor recurrence. PMID:24616500

Monoclonal Antibodies against the Drosophila Nervous System

NASA Astrophysics Data System (ADS)

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

1982-12-01

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

Presence of DNA methyltransferase activity and CpC methylation in Drosophila melanogaster.

PubMed

Panikar, Chitra S; Rajpathak, Shriram N; Abhyankar, Varada; Deshmukh, Saniya; Deobagkar, Deepti D

2015-12-01

Drosophila melanogaster lacks DNMT1/DNMT3 based methylation machinery. Despite recent reports confirming the presence of low DNA methylation in Drosophila; little is known about the methyltransferase. Therefore, in this study, we have aimed to investigate the possible functioning of DNA methyltransferase in Drosophila. The 14 K oligo microarray slide was incubated with native cell extract from adult Drosophila to check the presence of the methyltransferase activity. After incubation under appropriate conditions, the methylated oligo sequences were identified by the binding of anti 5-methylcytosine monoclonal antibody. The antibody bound to the methylated oligos was detected using Cy3 labeled secondary antibody. Methylation sensitive restriction enzyme mediated PCR was used to assess the methylation at a few selected loci identified on the array. It could be seen that a few of the total oligos got methylated under the assay conditions. Analysis of methylated oligo sequences provides evidence for the presence of de novo methyltransferase activity and allows identification of its sequence specificity in adult Drosophila. With the help of methylation sensitive enzymes we could detect presence of CpC methylation in the selected genomic regions. This study reports presence of an active DNA methyltransferase in adult Drosophila, which exhibits sequence specificity confirmed by presence of asymmetric methylation at corresponding sites in the genomic DNA. It also provides an innovative approach to investigate methylation specificity of a native methyltransferase.

A Buoyancy-based Method of Determining Fat Levels in Drosophila.

PubMed

Hazegh, Kelsey E; Reis, Tânia

2016-11-01

Drosophila melanogaster is a key experimental system in the study of fat regulation. Numerous techniques currently exist to measure levels of stored fat in Drosophila, but most are expensive and/or laborious and have clear limitations. Here, we present a method to quickly and cheaply determine organismal fat levels in L3 Drosophila larvae. The technique relies on the differences in density between fat and lean tissues and allows for rapid detection of fat and lean phenotypes. We have verified the accuracy of this method by comparison to body fat percentage as determined by neutral lipid extraction and gas chromatography coupled with mass spectrometry (GCMS). We furthermore outline detailed protocols for the collection and synchronization of larvae as well as relevant experimental recipes. The technique presented below overcomes the major shortcomings in the most widely used lipid quantitation methods and provides a powerful way to quickly and sensitively screen L3 larvae for fat regulation phenotypes while maintaining the integrity of the larvae. This assay has wide applications for the study of metabolism and fat regulation using Drosophila.

Functional sub-division of the Drosophila genome via chromatin looping

PubMed Central

Ahanger, Sajad H.; Shouche, Yogesh S.; Mishra, Rakesh K.

2013-01-01

Insulators help in organizing the eukaryotic genomes into physically and functionally autonomous regions through the formation of chromatin loops. Recent findings in Drosophila and vertebrates suggest that insulators anchor multiple loci through long-distance interactions which may be mechanistically linked to insulator function. Important to such processes in Drosophila is CP190, a common co-factor of insulator complexes. CP190 is also known to associate with the nuclear matrix, components of the RNAi machinery, active promoters and borders of the repressive chromatin domains. Although CP190 plays a pivotal role in insulator function in Drosophila, vertebrates lack a probable functional equivalent of CP190 and employ CTCF as the major factor to carry out insulator function/chromatin looping. In this review, we discuss the emerging role of CP190 in tethering genome, specifically in the perspective of insulator function in Drosophila. Future studies aiming genome-wide role of CP190 in chromatin looping is likely to give important insights into the mechanism of genome organization. PMID:23333867

Pluripotency and a secretion mechanism of Drosophila transglutaminase.

PubMed

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.

Three-Dimensional Genome Organization and Function in Drosophila

PubMed Central

Schwartz, Yuri B.; Cavalli, Giacomo

2017-01-01

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

Generation of a transgenic ORFeome library in Drosophila

PubMed Central

Bischof, Johannes; Sheils, Emma M.; Björklund, Mikael; Basler, Konrad

2014-01-01

Overexpression screens can be used to explore gene function in Drosophila melanogaster, but to demonstrate their full potential comprehensive and systematic collections of fly strains are required. Here we provide a protocol for high-throughput cloning of Drosophila open reading frames (ORFs) regulated by Upstream Activation Sequences (UAS sites); the resulting Gal4-inducible UAS-ORF plasmid library is then used to generate Drosophila strains by ΦC31 integrase-mediated site-specific integration. We also provide details for FLP/FRT-mediated in vivo exchange of epitope tags (or regulatory regions) in the ORF library strains, which further extends their potential applications. These transgenic UAS-ORF strains are a useful resource to complement and validate genetic experiments performed with loss-of-function mutants and RNAi lines. The duration of the complete protocol strongly depends on the number of ORFs required, but the procedure of injection and establishing balanced fly stocks can be completed within approx. 6-7 weeks for a few genes. PMID:24922270

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

PubMed Central

Hernández, Alejandro; Zalom, Frank G.

2012-01-01

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

Unique transposon landscapes are pervasive across Drosophila melanogaster genomes

PubMed Central

Rahman, Reazur; Chirn, Gung-wei; Kanodia, Abhay; Sytnikova, Yuliya A.; Brembs, Björn; Bergman, Casey M.; Lau, Nelson C.

2015-01-01

To understand how transposon landscapes (TLs) vary across animal genomes, we describe a new method called the Transposon Insertion and Depletion AnaLyzer (TIDAL) and a database of >300 TLs in Drosophila melanogaster (TIDAL-Fly). Our analysis reveals pervasive TL diversity across cell lines and fly strains, even for identically named sub-strains from different laboratories such as the ISO1 strain used for the reference genome sequence. On average, >500 novel insertions exist in every lab strain, inbred strains of the Drosophila Genetic Reference Panel (DGRP), and fly isolates in the Drosophila Genome Nexus (DGN). A minority (<25%) of transposon families comprise the majority (>70%) of TL diversity across fly strains. A sharp contrast between insertion and depletion patterns indicates that many transposons are unique to the ISO1 reference genome sequence. Although TL diversity from fly strains reaches asymptotic limits with increasing sequencing depth, rampant TL diversity causes unsaturated detection of TLs in pools of flies. Finally, we show novel transposon insertions negatively correlate with Piwi-interacting RNA (piRNA) levels for most transposon families, except for the highly-abundant roo retrotransposon. Our study provides a useful resource for Drosophila geneticists to understand how transposons create extensive genomic diversity in fly cell lines and strains. PMID:26578579

An infrared system for monitoring Drosophila motility during microgravity

NASA Technical Reports Server (NTRS)

Miller, Mark S.; Fortney, Michael D.; Keller, Tony S.

2002-01-01

Presently, the precise mechanisms of the aging process are unknown. Examination and comprehension of the aging process in other species could lead to significant advances in the understanding of human aging. Drosophila melanogaster (fruit fly), commonly used for aging studies, is a widely studied organism in terms of behavior, development, and genetics. Previous microgravity experiments have shown a significant decrease in the life span of young male Drosophila after microgravity exposure. This decrease in lifespan may be related to locomotor activity, a convenient measure of overall physiological performance. This study describes the design and performance of a Drosophila Infrared Motility Monitoring System (DIMMS). The DIMMS uses a unique design of two infrared (IR) beams per fly to measure the locomotor activity of 240 flies. Locomotor activity is measured in terms of number of IR crossings per unit time, instantaneous velocity, and continuous velocity. Ground-based results using the DIMMS equipment agree well with previous values for Drosophila locomotor velocity. DIMMS is an improvement over equipment previously used due to its ability to continuously monitor locomotor activity throughout short-duration microgravity exposure. DIMMS is also lightweight, compact, and power efficient. DIMMS has been flight tested onboard NASA's KC-135 reduced gravity research aircraft and a Nike-Orion sounding rocket.

An infrared system for monitoring Drosophila motility during microgravity.

PubMed

Miller, Mark S; Fortney, Michael D; Keller, Tony S

2002-12-01

Presently, the precise mechanisms of the aging process are unknown. Examination and comprehension of the aging process in other species could lead to significant advances in the understanding of human aging. Drosophila melanogaster (fruit fly), commonly used for aging studies, is a widely studied organism in terms of behavior, development, and genetics. Previous microgravity experiments have shown a significant decrease in the life span of young male Drosophila after microgravity exposure. This decrease in lifespan may be related to locomotor activity, a convenient measure of overall physiological performance. This study describes the design and performance of a Drosophila Infrared Motility Monitoring System (DIMMS). The DIMMS uses a unique design of two infrared (IR) beams per fly to measure the locomotor activity of 240 flies. Locomotor activity is measured in terms of number of IR crossings per unit time, instantaneous velocity, and continuous velocity. Ground-based results using the DIMMS equipment agree well with previous values for Drosophila locomotor velocity. DIMMS is an improvement over equipment previously used due to its ability to continuously monitor locomotor activity throughout short-duration microgravity exposure. DIMMS is also lightweight, compact, and power efficient. DIMMS has been flight tested onboard NASA's KC-135 reduced gravity research aircraft and a Nike-Orion sounding rocket.

The Knock-Limited Performance of Fuel Blends Containing Aromatics V : N-Propylbenzene, N-Butylbenzene, Isobutylbenzene, M-Xylene, and 1-Isopropyl-4-Methylbenzene

NASA Technical Reports Server (NTRS)

Meyer, Carl L.; Branstetter, J. Robert

1946-01-01

Results are reported of knock-limited tests of five aromatics, each individually blended with selected base fuels and tested with and without TEL, using 17.6, F-4, and F-3 small-scale engines. The five aromatics rated in the following order of decreasing antiknock effectiveness at fuel/air ratio 0.10: m-xylene, 1-isopropyl-4-methylbenzene, n-propylbenzene, isobutylbenzene, and n-butylbenzene.

New tools for the analysis of glial cell biology in Drosophila.

PubMed

Awasaki, Takeshi; Lee, Tzumin

2011-09-01

Because of its genetic, molecular, and behavioral tractability, Drosophila has emerged as a powerful model system for studying molecular and cellular mechanisms underlying the development and function of nervous systems. The Drosophila nervous system has fewer neurons and exhibits a lower glia:neuron ratio than is seen in vertebrate nervous systems. Despite the simplicity of the Drosophila nervous system, glial organization in flies is as sophisticated as it is in vertebrates. Furthermore, fly glial cells play vital roles in neural development and behavior. In addition, powerful genetic tools are continuously being created to explore cell function in vivo. In taking advantage of these features, the fly nervous system serves as an excellent model system to study general aspects of glial cell development and function in vivo. In this article, we review and discuss advanced genetic tools that are potentially useful for understanding glial cell biology in Drosophila. Copyright © 2011 Wiley-Liss, Inc.

Diverse radiofrequency sensitivity and radiofrequency effects of mobile or cordless phone near fields exposure in Drosophila melanogaster.

PubMed

Geronikolou, Styliani; Zimeras, Stelios; Davos, Constantinos H; Michalopoulos, Ioannis; Tsitomeneas, Stephanos

2014-01-01

The impact of electromagnetic fields on health is of increasing scientific interest. The aim of this study was to examine how the Drosophila melanogaster animal model is affected when exposed to portable or mobile phone fields. Two experiments have been designed and performed in the same laboratory conditions. Insect cultures were exposed to the near field of a 2G mobile phone (the GSM 2G networks support and complement in parallel the 3G wide band or in other words the transmission of information via voice signals is served by the 2G technology in both mobile phones generations) and a 1880 MHz cordless phone both digitally modulated by human voice. Comparison with advanced statistics of the egg laying of the second generation exposed and non-exposed cultures showed limited statistical significance for the cordless phone exposed culture and statistical significance for the 900 MHz exposed insects. We calculated by physics, simulated and illustrated in three dimensional figures the calculated near fields of radiation inside the experimenting vials and their difference. Comparison of the power of the two fields showed that the difference between them becomes null when the experimental cylinder radius and the height of the antenna increase. Our results suggest a possible radiofrequency sensitivity difference in insects which may be due to the distance from the antenna or to unexplored intimate factors. Comparing the near fields of the two frequencies bands, we see similar not identical geometry in length and height from the antenna and that lower frequencies tend to drive to increased radiofrequency effects.

Measurement of BTEX (benzene, toluene, ethybenzene, and xylene) levels at urban and semirural areas of Algiers City using passive air samplers.

PubMed

Kerchich, Yacine; Kerbachi, Rabah

2012-12-01

The study presents the levels of air pollution by aromatic organic compounds BTEX (benzene, toluene, ethylbenzene, o-, m-, and p-xylenes) in the city of Algiers. The sampling was carried out using Radiello passive sampler. Three sampling campaigns were carried out in roadside, tunnel, urban background, and semirural sites in Algiers. In order to determine the diurnal mean levels of air pollution by BTEX to which people are exposed, a modified passive sampler was used for the first time. In addition, monitoring of pollution inside vehicles was also made. In the spring of 2009, more than 27 samplings were carried out. In the background and road traffic sites the Radiello sampler was exposed for 7 days, whereas the time exposure was reduced to 1 day in the case of the vehicle as well as the tunnel. The results indicate that average benzene concentrations in the roadside and inside vehicle exceed largely the limit value of 5 microg m(-3) established by the European Community (EC). On the other hand, it has been noticed that the concentration levels of other BTEX are relatively high. Also, in order to identify the origin of emission sources, ratios and correlations between the BTEX species have been highlighted. This study shows that road traffic remains the main source of many local emission in Algiers. The vehicle fleet in Algeria is growing rapidly since the 1990s following economic growth and is responsible for the increasing air pollution in large cities. Because there are no data collection of BTEX carried out by national air quality network, all environmental and transportation policies are based on European emissions standards, but national emission standards are currently not in place. This work will contribute to the analysis of real emissions of BTEX in Algiers, for the development of management and for assessment of population exposure variation depending on the location in the city of Algiers.

T-Box Genes in Drosophila Limb Development.

PubMed

Pflugfelder, G O; Eichinger, F; Shen, J

2017-01-01

T-box genes are essential for limb development in vertebrates and arthropods. The Drosophila genome encodes eight T-box genes, six of which are expressed in limb ontogenesis. The Tbx20-related gene pair midline and H15 is essential for dorso-ventral patterning of the Drosophila legs. The three Tbx6-related Dorsocross genes are required for epithelial remodeling during wing development. The Drosophila gene optomotor-blind (omb) is the only member of the Tbx2 subfamily in the fly and is predominantly involved in wing development. Omb is essential for wing development and is sufficient to promote the development of a second wing pair. Targeted manipulations of omb expression have shown that the bulk omb requirement for wing development can be deconstructed into a number of individual functions. Even though omb expression in the wing disc is symmetrical with regard to the anterior/posterior (A/P) compartment boundary, anterior and posterior knockdowns have distinct consequences: Anterior Omb is required for the maintenance of a straight A/P lineage restriction boundary. Posterior Omb suppresses formation of an apical epithelial fold along the A/P boundary. Drosophila T-box gene expression is not confined to the ectoderm-derived epithelia of the imaginal discs. Both Doc and Omb are prominently expressed in leg disc muscle precursor cells. Omb is also strongly expressed in a tracheal branch that invades the extracellular matrix of the wing disc. The function of Doc and Omb in the latter tissues is not known, indicative of the many questions still open in the field. © 2017 Elsevier Inc. All rights reserved.

Fluctuation-Driven Neural Dynamics Reproduce Drosophila Locomotor Patterns

PubMed Central

Cruchet, Steeve; Gustafson, Kyle; Benton, Richard; Floreano, Dario

2015-01-01

The neural mechanisms determining the timing of even simple actions, such as when to walk or rest, are largely mysterious. One intriguing, but untested, hypothesis posits a role for ongoing activity fluctuations in neurons of central action selection circuits that drive animal behavior from moment to moment. To examine how fluctuating activity can contribute to action timing, we paired high-resolution measurements of freely walking Drosophila melanogaster with data-driven neural network modeling and dynamical systems analysis. We generated fluctuation-driven network models whose outputs—locomotor bouts—matched those measured from sensory-deprived Drosophila. From these models, we identified those that could also reproduce a second, unrelated dataset: the complex time-course of odor-evoked walking for genetically diverse Drosophila strains. Dynamical models that best reproduced both Drosophila basal and odor-evoked locomotor patterns exhibited specific characteristics. First, ongoing fluctuations were required. In a stochastic resonance-like manner, these fluctuations allowed neural activity to escape stable equilibria and to exceed a threshold for locomotion. Second, odor-induced shifts of equilibria in these models caused a depression in locomotor frequency following olfactory stimulation. Our models predict that activity fluctuations in action selection circuits cause behavioral output to more closely match sensory drive and may therefore enhance navigation in complex sensory environments. Together these data reveal how simple neural dynamics, when coupled with activity fluctuations, can give rise to complex patterns of animal behavior. PMID:26600381

Functional domains of the Drosophila Engrailed protein.

PubMed Central

Han, K; Manley, J L

1993-01-01

We have studied the transcriptional activity of the Drosophila homeodomain protein Engrailed (En) by using a transient expression assay employing Schneider L2 cells. En was found to very strongly repress promoters activated by a variety of different activator proteins. However, unlike another Drosophila homeodomain-containing repressor, Even-skipped (Eve), En was unable to repress the activity of several basal promoters in the absence of activator expression. These findings indicate that En is a specific repressor of activated transcription, and suggest that En may repress transcription by a different mechanism than Eve, perhaps by interfering with interactions between transcriptional activators and the general transcription machinery. By analyzing the properties of a variety of En mutants, we identified a minimal repression domain composed of 55 residues, which can function when fused to a heterologous DNA binding domain. Like repression domains identified in the Drosophila repressors Eve and Krüppel, the En repression domain is rich in alanine residues (26%), but unlike these other domains, is moderately charged (six arginine and three glutamic acid residues). Separate regions of En that may in some circumstances function in transcriptional activation were also identified. Images PMID:8334991

Methods to study Drosophila immunity.

PubMed

Neyen, Claudine; Bretscher, Andrew J; Binggeli, Olivier; Lemaitre, Bruno

2014-06-15

Innate immune mechanisms are well conserved throughout evolution, and many theoretical concepts, molecular pathways and gene networks are applicable to invertebrate model organisms as much as vertebrate ones. Drosophila immunity research benefits from an easily manipulated genome, a fantastic international resource of transgenic tools and over a quarter century of accumulated techniques and approaches to study innate immunity. Here we present a short collection of ways to challenge the fruit fly immune system with various pathogens and parasites, as well as read-outs to assess its functions, including cellular and humoral immune responses. Our review covers techniques for assessing the kinetics and efficiency of immune responses quantitatively and qualitatively, such as survival analysis, bacterial persistence, antimicrobial peptide gene expression, phagocytosis and melanisation assays. Finally, we offer a toolkit of Drosophila strains available to the research community for current and future research. Copyright © 2014 Elsevier Inc. All rights reserved.

The role of MOF in the ionizing radiation response is conserved in Drosophila melanogaster

PubMed Central

Bhadra, Manika P.; Horikoshi, Nobuo; Pushpavallipvalli, Sreerangam NCVL; Sarkar, Arpita; Bag, Indira; Krishnan, Anita; Lucchesi, John C.; Kumar, Rakesh; Yang, Qin; Pandita, Raj K.; Singh, Mayank; Bhadra, Utpal; Eissenberg, Joel C.; Pandita, Tej K.

2014-01-01

In Drosophila, males absent on the first (MOF) acetylates histone H4 at lysine 16 (H4K16ac). This acetylation mark is highly enriched on the male X chromosome and is required for dosage compensation in Drosophila but not utilized for such in mammals. Recently, we and others reported that mammalian MOF, through H4K16ac, has a critical role at multiple stages in the DNA damage response (DDR) and double-strand break repair pathways. The goal of this study was to test whether mof is similarly required for the response to ionizing radiation (IR) in Drosophila. We report that Drosophila mof mutations in males and females, as well as mof knockdown in SL-2 cells, reduce post-irradiation survival. MOF depletion in SL-2 cells also results in an elevated frequency of metaphases with chromosomal aberrations, suggesting that MOF is involved in DDR. Mutation in Drosophila mof also results in a defective mitotic checkpoint, enhanced apoptosis, and a defective p53 response post-irradiation. In addition, IR exposure enhanced H4K16ac levels in Drosophila as it also does in mammals. These results are the first to demonstrate a requirement for MOF in the whole animal IR response and suggest that the role of MOF in the response to IR is conserved between Drosophila and mammals. PMID:22072291

Genetics and neurobiology of aggression in Drosophila

PubMed Central

Zwarts, Liesbeth; Versteven, Marijke; Callaerts, Patrick

2012-01-01

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

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

USDA-ARS?s Scientific Manuscript database

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

Trehalose as an indicator of desiccation stress in Drosophila melanogaster larvae: A potential marker of anhydrobiosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thorat, Leena J.; Gaikwad, Sushama M.; Nath, Bimalendu B., E-mail: bbnath@unipune.ac.in

Highlights: Black-Right-Pointing-Pointer First report confirming anhydrobiosis in Drosophila melanogaster larvae. Black-Right-Pointing-Pointer Trehalose synthesis and accumulation in larvae that hydrolyzed on rehydration. Black-Right-Pointing-Pointer Trehalose synthesis in concert with the enzymes involved in trehalose metabolism. Black-Right-Pointing-Pointer Inhibition of trehalose hydrolysis in presence of a specific trehalase inhibitor. Black-Right-Pointing-Pointer Trehalose proposed as a reliable marker for biomonitoring of climate change studies. -- Abstract: In the current scenario of global climate change, desiccation is considered as one of the major environmental stressors for the biota exposed to altered levels of ambient temperature and humidity. Drosophila melanogaster, a cosmopolitan terrestrial insect has been chosen asmore » a humidity-sensitive bioindicator model for the present study since its habitat undergoes frequent stochastic and/or seasonally aggravated dehydration regimes. We report here for the first time the occurrence of anhydrobiosis in D. melanogaster larvae by subjecting them to desiccation stress under laboratory conditions. Larvae desiccated for ten hours at <5% relative humidity could enter anhydrobiosis and could revive upon rehydration followed by resumption of active metabolism. As revealed by FTIR and HPLC analyzes, our findings strongly indicated the synthesis and accumulation of trehalose in the desiccating larvae. Biochemical measurements pointed out the desiccation-responsive trehalose metabolic pathway that was found to be coordinated in concert with the enzymes trehalose 6-phosphate synthase and trehalase. Further, an inhibitor-based experimental approach using deoxynojirimycin, a specific trehalase inhibitor, demonstrated the pivotal role of trehalose in larval anhydrobiosis of D. melanogaster. We therefore propose trehalose as a potential marker for the assessment of anhydrobiosis in Drosophila. The present findings

Immunolocalization of the vesicular acetylcholine transporter in larval and adult Drosophila neurons.

PubMed

Boppana, Sridhar; Kendall, Natalie; Akinrinsola, Opeyemi; White, Daniel; Patel, Krushali; Lawal, Hakeem

2017-03-16

Vesicular acetylcholine transporter (VAChT) function is essential for organismal survival, mediating the packaging of acetylcholine (ACh) for exocytotic release. However, its expression pattern in the Drosophila brain has not been fully elucidated. To investigate the localization of VAChT, we developed an antibody against the C terminal region of the protein and we show that this antibody recognizes a 65KDa protein corresponding to VAChT on an immunoblot in both Drosophila head homogenates and in Schneider 2 cells. Further, we report for the first time the expression of VAChT in the antennal lobe and ventral nerve cord of Drosophila larva; and we independently confirm the expression of the protein in mushroom bodies and optic lobes of adult Drosophila. Importantly, we show that VAChT co-localizes with a synaptic vesicle marker in vivo, confirming previous reports of the localization of VAChT to synaptic terminals. Together, these findings help establish the vesicular localization of VAChT in cholinergic neurons in Drosophila and present an important molecular tool with which to dissect the function of the transporter in vivo. Copyright © 2017 Elsevier B.V. All rights reserved.

Drosophila as a genetic and cellular model for studies on axonal growth

PubMed Central

Sánchez-Soriano, Natalia; Tear, Guy; Whitington, Paul; Prokop, Andreas

2007-01-01

One of the most fascinating processes during nervous system development is the establishment of stereotypic neuronal networks. An essential step in this process is the outgrowth and precise navigation (pathfinding) of axons and dendrites towards their synaptic partner cells. This phenomenon was first described more than a century ago and, over the past decades, increasing insights have been gained into the cellular and molecular mechanisms regulating neuronal growth and navigation. Progress in this area has been greatly assisted by the use of simple and genetically tractable invertebrate model systems, such as the fruit fly Drosophila melanogaster. This review is dedicated to Drosophila as a genetic and cellular model to study axonal growth and demonstrates how it can and has been used for this research. We describe the various cellular systems of Drosophila used for such studies, insights into axonal growth cones and their cytoskeletal dynamics, and summarise identified molecular signalling pathways required for growth cone navigation, with particular focus on pathfinding decisions in the ventral nerve cord of Drosophila embryos. These Drosophila-specific aspects are viewed in the general context of our current knowledge about neuronal growth. PMID:17475018

Molecular Analysis of Core Kinetochore Composition and Assembly in Drosophila melanogaster

PubMed Central

Przewloka, Marcin R.; Archambault, Vincent; D'Avino, Pier Paolo; Lilley, Kathryn S.; Laue, Ernest D.; McAinsh, Andrew D.; Glover, David M.

2007-01-01

Background Kinetochores are large multiprotein complexes indispensable for proper chromosome segregation. Although Drosophila is a classical model organism for studies of chromosome segregation, little is known about the organization of its kinetochores. Methodology/Principal Findings We employed bioinformatics, proteomics and cell biology methods to identify and analyze the interaction network of Drosophila kinetochore proteins. We have shown that three Drosophila proteins highly diverged from human and yeast Ndc80, Nuf2 and Mis12 are indeed their orthologues. Affinity purification of these proteins from cultured Drosophila cells identified a further five interacting proteins with weak similarity to subunits of the SPC105/KNL-1, MIND/MIS12 and NDC80 kinetochore complexes together with known kinetochore associated proteins such as dynein/dynactin, spindle assembly checkpoint components and heterochromatin proteins. All eight kinetochore complex proteins were present at the kinetochore during mitosis and MIND/MIS12 complex proteins were also centromeric during interphase. Their down-regulation led to dramatic defects in chromosome congression/segregation frequently accompanied by mitotic spindle elongation. The systematic depletion of each individual protein allowed us to establish dependency relationships for their recruitment onto the kinetochore. This revealed the sequential recruitment of individual members of first, the MIND/MIS12 and then, NDC80 complex. Conclusions/Significance The Drosophila MIND/MIS12 and NDC80 complexes and the Spc105 protein, like their counterparts from other eukaryotic species, are essential for chromosome congression and segregation, but are highly diverged in sequence. Hierarchical dependence relationships of individual proteins regulate the assembly of Drosophila kinetochore complexes in a manner similar, but not identical, to other organisms. PMID:17534428

Sustainable Production of o-Xylene from Biomass-Derived Pinacol and Acrolein.

PubMed

Hu, Yancheng; Li, Ning; Li, Guangyi; Wang, Aiqin; Cong, Yu; Wang, Xiaodong; Zhang, Tao

2017-07-21

o-Xylene (OX) is a large-volume commodity chemical that is conventionally produced from fossil fuels. In this study, an efficient and sustainable two-step route is used to produce OX from biomass-derived pinacol and acrolein. In the first step, the phosphotungstic acid (HPW)-catalyzed pinacol dehydration in 1-ethyl-3-methylimidazolium chloride ([emim]Cl) selectively affords 2,3-dimethylbutadiene. The high selectivity of this reaction can be ascribed to the H-bonding interaction between Cl - and the hydroxy group of pinacol. The stabilization of the carbocation intermediate by the surrounding anion Cl - may be another reason for the high selectivity. Notably, the good reusability of the HPW/[emim]Cl system can reduce the waste output and production cost. In the second step, OX is selectively produced by a Diels-Alder reaction of 2,3-dimethylbutadiene and acrolein, followed by a Pd/C-catalyzed decarbonylation/aromatization cascade in a one-pot fashion. The sustainable two-step process efficiently produces renewable OX in 79 % overall yield. Analogously, biomass-derived crotonaldehyde and pinacol can also serve as the feedstocks for the production of 1,2,4-trimethylbenzene. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective Production of Renewable para-Xylene by Tungsten Carbide Catalyzed Atom-Economic Cascade Reactions.

PubMed

Dai, Tao; Li, Changzhi; Li, Lin; Zhao, Zongbao Kent; Zhang, Bo; Cong, Yu; Wang, Aiqin

2018-02-12

Tungsten carbide was employed as the catalyst in an atom-economic and renewable synthesis of para-xylene with excellent selectivity and yield from 4-methyl-3-cyclohexene-1-carbonylaldehyde (4-MCHCA). This intermediate is the product of the Diels-Alder reaction between the two readily available bio-based building blocks acrolein and isoprene. Our results suggest that 4-MCHCA undergoes a novel dehydroaromatization-hydrodeoxygenation cascade process by intramolecular hydrogen transfer that does not involve an external hydrogen source, and that the hydrodeoxygenation occurs through the direct dissociation of the C=O bond on the W 2 C surface. Notably, this process is readily applicable to the synthesis of various (multi)methylated arenes from bio-based building blocks, thus potentially providing a petroleum-independent solution to valuable aromatic compounds. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phenotypic and transcriptional response to selection for alcohol sensitivity in Drosophila melanogaster

PubMed Central

Morozova, Tatiana V; Anholt, Robert RH; Mackay, Trudy FC

2007-01-01

Background Alcoholism is a complex disorder determined by interactions between genetic and environmental risk factors. Drosophila represents a powerful model system to dissect the genetic architecture of alcohol sensitivity, as large numbers of flies can readily be reared in defined genetic backgrounds and under controlled environmental conditions. Furthermore, flies exposed to ethanol undergo physiological and behavioral changes that resemble human alcohol intoxication, including loss of postural control, sedation, and development of tolerance. Results We performed artificial selection for alcohol sensitivity for 35 generations and created duplicate selection lines that are either highly sensitive or resistant to ethanol exposure along with unselected control lines. We used whole genome expression analysis to identify 1,678 probe sets with different expression levels between the divergent lines, pooled across replicates, at a false discovery rate of q < 0.001. We assessed to what extent genes with altered transcriptional regulation might be causally associated with ethanol sensitivity by measuring alcohol sensitivity of 37 co-isogenic P-element insertional mutations in 35 candidate genes, and found that 32 of these mutants differed in sensitivity to ethanol exposure from their co-isogenic controls. Furthermore, 23 of these novel genes have human orthologues. Conclusion Combining whole genome expression profiling with selection for genetically divergent lines is an effective approach for identifying candidate genes that affect complex traits, such as alcohol sensitivity. Because of evolutionary conservation of function, it is likely that human orthologues of genes affecting alcohol sensitivity in Drosophila may contribute to alcohol-associated phenotypes in humans. PMID:17973985

On-line CO, CO2 emissions evaluation and (benzene, toluene, xylene) determination from experimental burn of tropical biomass.

PubMed

Tawfiq, Mohammed F; Aroua, Mohamed Kheireddine; Sulaiman, Nik Meriam Nik

2015-07-01

Atmospheric pollution and global warming issues are increasingly becoming major environmental concerns. Fire is one of the significant sources of pollutant gases released into the atmosphere; and tropical biomass fires, which are of particular interest in this study, contribute greatly to the global budget of CO and CO2. This pioneer research simulates the natural biomass burning strategy in Malaysia using an experimental burning facility. The investigation was conducted on the emissions (CO2, CO, and Benzene, Toluene, Ethylbenzene, Xylenes (BTEX)) from ten tropical biomass species. The selected species represent the major tropical forests that are frequently subjected to dry forest fire incidents. An experimental burning facility equipped with an on-line gas analyzer was employed to determine the burning emissions. The major emission factors were found to vary among the species, and the specific results were as follows. The moisture content of a particular biomass greatly influenced its emission pattern. The smoke analysis results revealed the existence of BTEX, which were sampled from a combustion chamber by enrichment traps aided with a universal gas sampler. The BTEX were determined by organic solvent extraction followed by GC/MS quantification, the results of which suggested that the biomass burning emission factor contributed significant amounts of benzene, toluene, and m,p-xylene. The modified combustion efficiency (MCE) changed in response to changes in the sample moisture content. Therefore, this study concluded that the emission of some pollutants mainly depends on the burning phase and sample moisture content of the biomass. Copyright © 2015. Published by Elsevier B.V.

Optimization of the p-xylene oxidation process by a multi-objective differential evolution algorithm with adaptive parameters co-derived with the population-based incremental learning algorithm

NASA Astrophysics Data System (ADS)

Guo, Zhan; Yan, Xuefeng

2018-04-01

Different operating conditions of p-xylene oxidation have different influences on the product, purified terephthalic acid. It is necessary to obtain the optimal combination of reaction conditions to ensure the quality of the products, cut down on consumption and increase revenues. A multi-objective differential evolution (MODE) algorithm co-evolved with the population-based incremental learning (PBIL) algorithm, called PBMODE, is proposed. The PBMODE algorithm was designed as a co-evolutionary system. Each individual has its own parameter individual, which is co-evolved by PBIL. PBIL uses statistical analysis to build a model based on the corresponding symbiotic individuals of the superior original individuals during the main evolutionary process. The results of simulations and statistical analysis indicate that the overall performance of the PBMODE algorithm is better than that of the compared algorithms and it can be used to optimize the operating conditions of the p-xylene oxidation process effectively and efficiently.

The route of infection determines Wolbachia antibacterial protection in Drosophila.

PubMed

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.

Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

PubMed Central

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

2016-01-01

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

Hypergravity-induced altered behavior in Drosophila

NASA Astrophysics Data System (ADS)

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

2012-07-01

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

Autophagy in Drosophila: From Historical Studies to Current Knowledge

PubMed Central

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

2014-01-01

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

Effects of hypo-O-GlcNAcylation on Drosophila development.

PubMed

Mariappa, Daniel; Ferenbach, Andrew T; van Aalten, Daan M F

2018-05-11

Post-translational modification of serine/threonine residues in nucleocytoplasmic proteins with GlcNAc ( O -GlcNAcylation) is an essential regulatory mechanism in many cellular processes. In Drosophila , null mutants of the Polycomb gene O -GlcNAc transferase ( OGT ; also known as super sex combs ( sxc )) display homeotic phenotypes. To dissect the requirement for O -GlcNAc signaling in Drosophila development, we used CRISPR/Cas9 gene editing to generate rationally designed sxc catalytically hypomorphic or null point mutants. Of the fertile males derived from embryos injected with the CRISPR/Cas9 reagents, 25% produced progeny carrying precise point mutations with no detectable off-target effects. One of these mutants, the catalytically inactive sxc K872M , was recessive lethal, whereas a second mutant, the hypomorphic sxc H537A , was homozygous viable. We observed that reduced total protein O -GlcNAcylation in the sxc H537A mutant is associated with a wing vein phenotype and temperature-dependent lethality. Genetic interaction between sxc H537A and a null allele of Drosophila host cell factor ( dHcf ), encoding an extensively O -GlcNAcylated transcriptional coactivator, resulted in abnormal scutellar bristle numbers. A similar phenotype was also observed in sxc H537A flies lacking a copy of skuld ( skd ), a Mediator complex gene known to affect scutellar bristle formation. Interestingly, this phenotype was independent of OGT Polycomb function or dHcf downstream targets. In conclusion, the generation of the endogenous OGT hypomorphic mutant sxc H537A enabled us to identify pleiotropic effects of globally reduced protein O -GlcNAc during Drosophila development. The mutants generated and phenotypes observed in this study provide a platform for discovery of OGT substrates that are critical for Drosophila development. © 2018 Mariappa et al.

Epigenetic Telomere Protection by Drosophila DNA Damage Response Pathways

PubMed Central

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

2006-01-01

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

Epigenetic telomere protection by Drosophila DNA damage response pathways.

PubMed

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.

Reduction of dopamine level enhances the attractiveness of male Drosophila to other males.

PubMed

Liu, Tong; Dartevelle, Laurence; Yuan, Chunyan; Wei, Hongping; Wang, Ying; Ferveur, Jean-François; Guo, Aike

2009-01-01

Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior.

Reduction of Dopamine Level Enhances the Attractiveness of Male Drosophila to Other Males

PubMed Central

Liu, Tong; Dartevelle, Laurence; Yuan, Chunyan; Wei, Hongping; Wang, Ying; Ferveur, Jean-François; Guo, Aike

2009-01-01

Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior. PMID:19238209

Neuromodulation of Innate Behaviors in Drosophila.

PubMed

Kim, Susy M; Su, Chih-Ying; Wang, Jing W

2017-07-25

Animals are born with a rich repertoire of robust behaviors that are critical for their survival. However, innate behaviors are also highly adaptable to an animal's internal state and external environment. Neuromodulators, including biogenic amines, neuropeptides, and hormones, are released to signal changes in animals' circumstances and serve to reconfigure neural circuits. This circuit flexibility allows animals to modify their behavioral responses according to environmental cues, metabolic demands, and physiological states. Aided by powerful genetic tools, researchers have made remarkable progress in Drosophila melanogaster to address how a myriad of contextual information influences the input-output relationship of hardwired circuits that support a complex behavioral repertoire. Here we highlight recent advances in understanding neuromodulation of Drosophila innate behaviors, with a special focus on feeding, courtship, aggression, and postmating behaviors.

Induced antiviral innate immunity in Drosophila.

PubMed

Lamiable, Olivier; Imler, Jean-Luc

2014-08-01

Immunity to viral infections in the model organism Drosophila melanogaster involves both RNA interference and additional induced responses. The latter include not only cellular mechanisms such as programmed cell death and autophagy, but also the induction of a large set of genes, some of which contribute to the control of viral replication and resistance to infection. This induced response to infection is complex and involves both virus-specific and cell-type specific mechanisms. We review here recent developments, from the sensing of viral infection to the induction of signaling pathways and production of antiviral effector molecules. Our current understanding, although still partial, validates the Drosophila model of antiviral induced immunity for insect pests and disease vectors, as well as for mammals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Walking modulates speed sensitivity in Drosophila motion vision.

PubMed

Chiappe, M Eugenia; Seelig, Johannes D; Reiser, Michael B; Jayaraman, Vivek

2010-08-24

Changes in behavioral state modify neural activity in many systems. In some vertebrates such modulation has been observed and interpreted in the context of attention and sensorimotor coordinate transformations. Here we report state-dependent activity modulations during walking in a visual-motor pathway of Drosophila. We used two-photon imaging to monitor intracellular calcium activity in motion-sensitive lobula plate tangential cells (LPTCs) in head-fixed Drosophila walking on an air-supported ball. Cells of the horizontal system (HS)--a subgroup of LPTCs--showed stronger calcium transients in response to visual motion when flies were walking rather than resting. The amplified responses were also correlated with walking speed. Moreover, HS neurons showed a relatively higher gain in response strength at higher temporal frequencies, and their optimum temporal frequency was shifted toward higher motion speeds. Walking-dependent modulation of HS neurons in the Drosophila visual system may constitute a mechanism to facilitate processing of higher image speeds in behavioral contexts where these speeds of visual motion are relevant for course stabilization. Copyright 2010 Elsevier Ltd. All rights reserved.

High Yield Magnetic Nanoparticles Filled Multiwalled Carbon Nanotubes Using Pulsed Laser Deposition

DTIC Science & Technology

2008-12-01

exposing silica structures to a mixture of ferrocene and xylene at 770 oC for 10 min. The furnace is pumped down to ~200 mtorr in argon bleed and then...heated to the temperature of 770 oC. The solution of ferrocene dissolved in xylene (~0.01g/ml) is pre-heated in a bubbler to 175 oC and then passed

Estimating Divergence Dates and Substitution Rates in the Drosophila Phylogeny

PubMed Central

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

2012-01-01

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

Drosophila as a Model for Human Diseases-Focus on Innate Immunity in Barrier Epithelia.

PubMed

Bergman, P; Seyedoleslami Esfahani, S; Engström, Y

2017-01-01

Epithelial immunity protects the host from harmful microbial invaders but also controls the beneficial microbiota on epithelial surfaces. When this delicate balance between pathogen and symbiont is disturbed, clinical disease often occurs, such as in inflammatory bowel disease, cystic fibrosis, or atopic dermatitis, which all can be in part linked to impairment of barrier epithelia. Many innate immune receptors, signaling pathways, and effector molecules are evolutionarily conserved between human and Drosophila. This review describes the current knowledge on Drosophila as a model for human diseases, with a special focus on innate immune-related disorders of the gut, lung, and skin. The discovery of antimicrobial peptides, the crucial role of Toll and Toll-like receptors, and the evolutionary conservation of signaling to the immune systems of both human and Drosophila are described in a historical perspective. Similarities and differences between human and Drosophila are discussed; current knowledge on receptors, signaling pathways, and effectors are reviewed, including antimicrobial peptides, reactive oxygen species, as well as autophagy. We also give examples of human diseases for which Drosophila appears to be a useful model. In addition, the limitations of the Drosophila model are mentioned. Finally, we propose areas for future research, which include using the Drosophila model for drug screening, as a validation tool for novel genetic mutations in humans and for exploratory research of microbiota-host interactions, with relevance for infection, wound healing, and cancer. © 2017 Elsevier Inc. All rights reserved.

A Programmable Optical Stimulator for the Drosophila Eye.

PubMed

Chen, Xinping; Leon-Salas, Walter D; Zigon, Taylor; Ready, Donald F; Weake, Vikki M

2017-10-01

A programmable optical stimulator for Drosophila eyes is presented. The target application of the stimulator is to induce retinal degeneration in fly photoreceptor cells by exposing them to light in a controlled manner. The goal of this work is to obtain a reproducible system for studying age-related changes in susceptibility to environmental ocular stress. The stimulator uses light emitting diodes and an embedded computer to control illuminance, color (blue or red) and duration in two independent chambers. Further, the stimulator is equipped with per-chamber light and temperature sensors and a fan to monitor light intensity and to control temperature. An ON/OFF temperature control implemented on the embedded computer keeps the temperature from reaching levels that will induce the heat shock stress response in the flies. A custom enclosure was fabricated to house the electronic components of the stimulator. The enclosure provides a light-impermeable environment that allows air flow and lets users easily load and unload fly vials. Characterization results show that the fabricated stimulator can produce light at illuminances ranging from 0 to 16000 lux and power density levels from 0 to 7.2 mW/cm 2 for blue light. For red light the maximum illuminance is 8000 lux which corresponds to a power density of 3.54 mW/cm 2 . The fans and the ON/OFF temperature control are able to keep the temperature inside the chambers below 28.17°C. Experiments with white-eye male flies were performed to assess the ability of the fabricated simulator to induce blue light-dependent retinal degeneration. Retinal degeneration is observed in flies exposed to 8 hours of blue light at 7949 lux. Flies in a control experiment with no light exposure show no retinal degeneration. Flies exposed to red light for the similar duration and light intensity (8 hours and 7994 lux) do not show retinal degeneration either. Hence, the fabricated stimulator can be used to create environmental ocular stress

Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

NASA Astrophysics Data System (ADS)

Li, Ying; Liu, Zengrong

MicroRNAs (miRNAs) interact with 3‧untranslated region (UTR) elements of target genes to regulate mRNA stability or translation, and play a crucial role in regulating many different biological processes. bantam, a conserved miRNA, is involved in several functions, such as regulating Drosophila growth and circadian rhythm. Recently, it has been discovered that bantam plays a crucial role in the core circadian pacemaker. In this paper, based on experimental observations, a detailed dynamical model of bantam-regulated circadian clock system is developed to show the post-transcriptional behaviors in the modulation of Drosophila circadian rhythm, in which the regulation of bantam is incorporated into a classical model. The dynamical behaviors of the model are consistent with the experimental observations, which shows that bantam is an important regulator of Drosophila circadian rhythm. The sensitivity analysis of parameters demonstrates that with the regulation of bantam the system is more sensitive to perturbations, indicating that bantam regulation makes it easier for the organism to modulate its period against the environmental perturbations. The effectiveness in rescuing locomotor activity rhythms of mutated flies shows that bantam is necessary for strong and sustained rhythms. In addition, the biological mechanisms of bantam regulation are analyzed, which may help us more clearly understand Drosophila circadian rhythm regulated by other miRNAs.

Zeolite/iron oxide composite as sorbent for magnetic solid-phase extraction of benzene, toluene, ethylbenzene and xylenes from water samples prior to gas chromatography⬜mass spectrometry.

PubMed

Fernández, Elena; Vidal, Lorena; Canals, Antonio

2016-08-05

This study reports a new composite based on ZSM-5 zeolite decorated with iron oxide magnetic nanoparticles as a valuable sorbent for magnetic solid-phase extraction (MSPE). A proposal is made to determine benzene, toluene, ethylbenzene and xylenes (BTEX) as model analytes in water samples using gas chromatography-mass spectrometry. A two-step multivariate optimization strategy, using Plackett⬜Burman and circumscribed central composite designs, was employed to optimize experimental parameters affecting MSPE. The method was evaluated under optimized extraction conditions (i.e., amount of sorbent, 138mg; extraction time, 11min; sample pH, pH of water (i.e., 5.5⬜6.5); eluent solvent volume, 0.5mL; and elution time, 5min), obtaining a linear response from 1 to 100μgL(↙1) for benzene; from 10 to 100μgL(↙1) for toluene, ethylbenzene and o-xylene; and from 10 to 75μgL(↙1) for m,p-xylene. The repeatability of the proposed method was evaluated at a 40μgL(↙1) spiking level and coefficients of variation ranged between 8 and 11% (n=5). Limits of detection were found to be 0.3μgL(↙1) for benzene and 3μgL(↙1) for the other analytes. These values satisfy the current normative of the Environmental Protection Agency and European Union for BTEX content in waters for human consumption. Finally, drinking water, wastewater and river water were selected as real water samples to assess the applicability of the method. Relative recoveries varied between 85% and 114% showing negligible matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

The myosin ID pathway and left-right asymmetry in Drosophila.

PubMed

Géminard, Charles; González-Morales, Nicanor; Coutelis, Jean-Baptiste; Noselli, Stéphane

2014-06-01

Drosophila is a classical model to study body patterning, however left-right (L/R) asymmetry had remained unexplored, until recently. The discovery of the conserved myosin ID gene as a major determinant of L/R asymmetry has revealed a novel L/R pathway involving the actin cytoskeleton and the adherens junction. In this process, the HOX gene Abdominal-B plays a major role through the control of myosin ID expression and therefore symmetry breaking. In this review, we present organs and markers showing L/R asymmetry in Drosophila and discuss our current understanding of the underlying molecular genetic mechanisms. Drosophila represents a valuable model system revealing novel strategies to establish L/R asymmetry in invertebrates and providing an evolutionary perspective to the problem of laterality in bilateria. © 2014 Wiley Periodicals, Inc.

Open-field arena boundary is a primary object of exploration for Drosophila

PubMed Central

Soibam, Benjamin; Mann, Monica; Liu, Lingzhi; Tran, Jessica; Lobaina, Milena; Kang, Yuan Yuan; Gunaratne, Gemunu H; Pletcher, Scott; Roman, Gregg

2012-01-01

Drosophila adults, when placed into a novel open-field arena, initially exhibit an elevated level of activity followed by a reduced stable level of spontaneous activity and spend a majority of time near the arena edge, executing motions along the walls. In order to determine the environmental features that are responsible for the initial high activity and wall-following behavior exhibited during exploration, we examined wild-type and visually impaired mutants in arenas with different vertical surfaces. These experiments support the conclusion that the wall-following behavior of Drosophila is best characterized by a preference for the arena boundary, and not thigmotaxis or centrophobicity. In circular arenas, Drosophila mostly move in trajectories with low turn angles. Since the boundary preference could derive from highly linear trajectories, we further developed a simulation program to model the effects of turn angle on the boundary preference. In an hourglass-shaped arena with convex-angled walls that forced a straight versus wall-following choice, the simulation with constrained turn angles predicted general movement across a central gap, whereas Drosophila tend to follow the wall. Hence, low turn angled movement does not drive the boundary preference. Lastly, visually impaired Drosophila demonstrate a defect in attenuation of the elevated initial activity. Interestingly, the visually impaired w1118 activity decay defect can be rescued by increasing the contrast of the arena's edge, suggesting that the activity decay relies on visual detection of the boundary. The arena boundary is, therefore, a primary object of exploration for Drosophila. PMID:22574279

Neuronal Cbl Controls Biosynthesis of Insulin-Like Peptides in Drosophila melanogaster

PubMed Central

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

The Immune Phenotype of Three Drosophila Leukemia Models.

PubMed

Arefin, Badrul; Kunc, Martin; Krautz, Robert; Theopold, Ulrich

2017-07-05

Many leukemia patients suffer from dysregulation of their immune system, making them more susceptible to infections and leading to general weakening (cachexia). Both adaptive and innate immunity are affected. The fruit fly Drosophila melanogaster has an innate immune system, including cells of the myeloid lineage (hemocytes). To study Drosophila immunity and physiology during leukemia, we established three models by driving expression of a dominant-active version of the Ras oncogene ( Ras V12 ) alone or combined with knockdowns of tumor suppressors in Drosophila hemocytes. Our results show that phagocytosis, hemocyte migration to wound sites, wound sealing, and survival upon bacterial infection of leukemic lines are similar to wild type. We find that in all leukemic models the two major immune pathways (Toll and Imd) are dysregulated. Toll-dependent signaling is activated to comparable extents as after wounding wild-type larvae, leading to a proinflammatory status. In contrast, Imd signaling is suppressed. Finally, we notice that adult tissue formation is blocked and degradation of cell masses during metamorphosis of leukemic lines, which is akin to the state of cancer-dependent cachexia. To further analyze the immune competence of leukemic lines, we used a natural infection model that involves insect-pathogenic nematodes. We identified two leukemic lines that were sensitive to nematode infections. Further characterization demonstrates that despite the absence of behavioral abnormalities at the larval stage, leukemic larvae show reduced locomotion in the presence of nematodes. Taken together, this work establishes new Drosophila models to study the physiological, immunological, and behavioral consequences of various forms of leukemia. Copyright © 2017 Arefin et al.

Post-eclosion odor experience modifies olfactory receptor neuron coding in Drosophila

PubMed Central

Iyengar, Atulya; Chakraborty, Tuhin Subhra; Goswami, Sarit Pati; Wu, Chun-Fang; Siddiqi, Obaid

2010-01-01

Olfactory responses of Drosophila undergo pronounced changes after eclosion. The flies develop attraction to odors to which they are exposed and aversion to other odors. Behavioral adaptation is correlated with changes in the firing pattern of olfactory receptor neurons (ORNs). In this article, we present an information-theoretic analysis of the firing pattern of ORNs. Flies reared in a synthetic odorless medium were transferred after eclosion to three different media: (i) a synthetic medium relatively devoid of odor cues, (ii) synthetic medium infused with a single odorant, and (iii) complex cornmeal medium rich in odors. Recordings were made from an identified sensillum (type II), and the Jensen–Shannon divergence (DJS) was used to assess quantitatively the differences between ensemble spike responses to different odors. Analysis shows that prolonged exposure to ethyl acetate and several related esters increases sensitivity to these esters but does not improve the ability of the fly to distinguish between them. Flies exposed to cornmeal display varied sensitivity to these odorants and at the same time develop greater capacity to distinguish between odors. Deprivation of odor experience on an odorless synthetic medium leads to a loss of both sensitivity and acuity. Rich olfactory experience thus helps to shape the ORNs response and enhances its discriminative power. The experiments presented here demonstrate an experience-dependent adaptation at the level of the receptor neuron. PMID:20448199

Post-eclosion odor experience modifies olfactory receptor neuron coding in Drosophila.

PubMed

Iyengar, Atulya; Chakraborty, Tuhin Subhra; Goswami, Sarit Pati; Wu, Chun-Fang; Siddiqi, Obaid

2010-05-25

Olfactory responses of Drosophila undergo pronounced changes after eclosion. The flies develop attraction to odors to which they are exposed and aversion to other odors. Behavioral adaptation is correlated with changes in the firing pattern of olfactory receptor neurons (ORNs). In this article, we present an information-theoretic analysis of the firing pattern of ORNs. Flies reared in a synthetic odorless medium were transferred after eclosion to three different media: (i) a synthetic medium relatively devoid of odor cues, (ii) synthetic medium infused with a single odorant, and (iii) complex cornmeal medium rich in odors. Recordings were made from an identified sensillum (type II), and the Jensen-Shannon divergence (D(JS)) was used to assess quantitatively the differences between ensemble spike responses to different odors. Analysis shows that prolonged exposure to ethyl acetate and several related esters increases sensitivity to these esters but does not improve the ability of the fly to distinguish between them. Flies exposed to cornmeal display varied sensitivity to these odorants and at the same time develop greater capacity to distinguish between odors. Deprivation of odor experience on an odorless synthetic medium leads to a loss of both sensitivity and acuity. Rich olfactory experience thus helps to shape the ORNs response and enhances its discriminative power. The experiments presented here demonstrate an experience-dependent adaptation at the level of the receptor neuron.

Kinetics of Doubletime Kinase-dependent Degradation of the Drosophila Period Protein*

PubMed Central

Syed, Sheyum; Saez, Lino; Young, Michael W.

2011-01-01

Robust circadian oscillations of the proteins PERIOD (PER) and TIMELESS (TIM) are hallmarks of a functional clock in the fruit fly Drosophila melanogaster. Early morning phosphorylation of PER by the kinase Doubletime (DBT) and subsequent PER turnover is an essential step in the functioning of the Drosophila circadian clock. Here using time-lapse fluorescence microscopy we study PER stability in the presence of DBT and its short, long, arrhythmic, and inactive mutants in S2 cells. We observe robust PER degradation in a DBT allele-specific manner. With the exception of doubletime-short (DBTS), all mutants produce differential PER degradation profiles that show direct correspondence with their respective Drosophila behavioral phenotypes. The kinetics of PER degradation with DBTS in cell culture resembles that with wild-type DBT and posits that, in flies DBTS likely does not modulate the clock by simply affecting PER degradation kinetics. For all the other tested DBT alleles, the study provides a simple model in which the changes in Drosophila behavioral rhythms can be explained solely by changes in the rate of PER degradation. PMID:21659538

Distribution and activity of Drosophila suzukii in cultivated raspberry and surrounding vegetation

USDA-ARS?s Scientific Manuscript database

Spotted wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), readily utilizes wild ‘Himalaya’ blackberry (HB) Rubus armeniacus Focke, as a refuge, among other non-crop host plants, and is suspected of invading berry and stone fruit crops from adjacent field margins. Studies were c...

Axons guided by insulin receptor in Drosophila visual system.

PubMed

Song, Jianbo; Wu, Lingling; Chen, Zun; Kohanski, Ronald A; Pick, Leslie

2003-04-18

Insulin receptors are abundant in the central nervous system, but their roles remain elusive. Here we show that the insulin receptor functions in axon guidance. The Drosophila insulin receptor (DInR) is required for photoreceptor-cell (R-cell) axons to find their way from the retina to the brain during development of the visual system. DInR functions as a guidance receptor for the adapter protein Dock/Nck. This function is independent of Chico, the Drosophila insulin receptor substrate (IRS) homolog.

Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway.

PubMed

Troutwine, B R; Ghezzi, A; Pietrzykowski, A Z; Atkinson, N S

2016-04-01

A growing body of evidence has shown that alcohol alters the activity of the innate immune system and that changes in innate immune system activity can influence alcohol-related behaviors. Here, we show that the Toll innate immune signaling pathway modulates the level of alcohol resistance in Drosophila. In humans, a low level of response to alcohol is correlated with increased risk of developing an alcohol use disorder. The Toll signaling pathway was originally discovered in, and has been extensively studied in Drosophila. The Toll pathway is a major regulator of innate immunity in Drosophila, and mammalian Toll-like receptor signaling has been implicated in alcohol responses. Here, we use Drosophila-specific genetic tools to test eight genes in the Toll signaling pathway for effects on the level of response to ethanol. We show that increasing the activity of the pathway increases ethanol resistance whereas decreasing the pathway activity reduces ethanol resistance. Furthermore, we show that gene products known to be outputs of innate immune signaling are rapidly induced following ethanol exposure. The interaction between the Toll signaling pathway and ethanol is rooted in the natural history of Drosophila melanogaster. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Second-Order Conditioning in "Drosophila"

ERIC Educational Resources Information Center

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

2011-01-01

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

Effects of methylmercury and alcohol exposure in Drosophila melanogaster: Potential risks in neurodevelopmental disorders.

PubMed

Chauhan, Ved; Chauhan, Abha

2016-06-01

Extensive evidence suggests the role of oxidative stress in autism and other neurodevelopmental disorders. In this study, we investigated whether methylmercury (MeHg) and/or alcohol exposure has deleterious effects in Drosophila melanogaster (fruit flies). A diet containing different concentrations of MeHg in Drosophila induced free radical generation and increased lipid peroxidation (markers of oxidative stress) in a dose-dependent manner. This effect of MeHg on oxidative stress was enhanced by further exposure to alcohol. It was observed that alcohol alone could also induce free radical generation in flies. After alcohol exposure, MeHg did not affect the immobilization of flies, but it increased the recovery time in a concentration-dependent manner. MeHg significantly inhibited the activity of alcohol dehydrogenase (ADH) in a dose-dependent manner. Linear regression analysis showed a significant negative correlation between ADH activity and recovery time upon alcohol exposure in the flies fed a diet with MeHg. This relationship between ADH activity and recovery time after alcohol exposure was confirmed by adding 4-methyl pyrazole (an inhibitor of ADH) to the diet for the flies. These results suggest that consumption of alcohol by pregnant mothers who are exposed to MeHg may lead to increased oxidative stress and to increased length of time for alcohol clearance, which may have a direct impact on the development of the fetus, thereby increasing the risk of neurodevelopmental disorders. Published by Elsevier Ltd.

Hold on: females modulate sperm depletion from storage sites in the fly Drosophila melanogaster.

PubMed

Bloch Qazi, Margaret C; Hogdal, Leah

2010-09-01

Among many species of insects, females gain fitness benefits by producing numerous offspring. Yet actions related to producing numerous offspring such as mating with multiple males, producing oocytes and placing offspring in sub-optimal environments incur costs. Females can decrease the magnitude of these costs by retaining gametes when suitable oviposition sites are absent. We used the pomace fly, Drosophila melanogaster, to explore how the availability of fresh feeding/oviposition medium influenced female fitness via changes in offspring survivorship and the modulation of gamete release. Availability of fresh medium affected the absolute number and temporal production of offspring. This outcome was attributable to both decreased larval survival under crowded conditions and to female modulation of gamete release. Direct examination of the number of sperm retained among the different female storage organs revealed that females 'hold on' to sperm, retaining more sperm in storage, disproportionately within the spermathecae, when exposed infrequently to fresh medium. Despite this retention, females with lower rates of storage depletion exhibited decreased sperm use efficiency shortly after mating. This study provides direct evidence that females influence the rate of sperm depletion from specific storage sites in a way that can affect both female and male fitness. The possible adaptive significance of selective gamete utilization by female Drosophila includes lowering costs associated with frequent remating and larval overcrowding when oviposition sites are limiting, as well as potentially influencing paternity when females store sperm from multiple males.

Patterns of Nucleotide Diversity at the Regions Encompassing the Drosophila Insulin-Like Peptide (dilp) Genes: Demography vs. Positive Selection in Drosophila melanogaster

PubMed Central

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

Neurophysiology of Drosophila Models of Parkinson's Disease

PubMed Central

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

2015-01-01

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

Molecular Genetic Analysis of Ethanol Intoxication in Drosophila melanogaster.

PubMed

Heberlein, Ulrike; Wolf, Fred W; Rothenfluh, Adrian; Guarnieri, Douglas J

2004-08-01

Recently, the fruit fly Drosophila melanogaster has been introduced as a model system to study the molecular bases of a variety of ethanol-induced behaviors. It became immediately apparent that the behavioral changes elicited by acute ethanol exposure are remarkably similar in flies and mammals. Flies show signs of acute intoxication, which range from locomotor stimulation at low doses to complete sedation at higher doses and they develop tolerance upon intermittent ethanol exposure. Genetic screens for mutants with altered responsiveness to ethanol have been carried out and a few of the disrupted genes have been identified. This analysis, while still in its early stages, has already revealed some surprising molecular parallels with mammals. The availability of powerful tools for genetic manipulation in Drosophila, together with the high degree of conservation at the genomic level, make Drosophila a promising model organism to study the mechanism by which ethanol regulates behavior and the mechanisms underlying the organism's adaptation to long-term ethanol exposure.

RNA editing in Drosophila melanogaster: new targets and functionalconsequences

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2006-09-05

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

Yeast Communities of Diverse Drosophila Species: Comparison of Two Symbiont Groups in the Same Hosts

PubMed Central

Eisen, Jonathan A.; Kopp, Artyom

2012-01-01

The combination of ecological diversity with genetic and experimental tractability makes Drosophila a powerful model for the study of animal-associated microbial communities. Despite the known importance of yeasts in Drosophila physiology, behavior, and fitness, most recent work has focused on Drosophila-bacterial interactions. In order to get a more complete understanding of the Drosophila microbiome, we characterized the yeast communities associated with different Drosophila species collected around the world. We focused on the phylum Ascomycota because it constitutes the vast majority of the Drosophila-associated yeasts. Our sampling strategy allowed us to compare the distribution and structure of the yeast and bacterial communities in the same host populations. We show that yeast communities are dominated by a small number of abundant taxa, that the same yeast lineages are associated with different host species and populations, and that host diet has a greater effect than host species on yeast community composition. These patterns closely parallel those observed in Drosophila bacterial communities. However, we do not detect a significant correlation between the yeast and bacterial communities of the same host populations. Comparative analysis of different symbiont groups provides a more comprehensive picture of host-microbe interactions. Future work on the role of symbiont communities in animal physiology, ecological adaptation, and evolution would benefit from a similarly holistic approach. PMID:22885750

Developing a new bait for spotted wing Drosophila in organic cherry production

USDA-ARS?s Scientific Manuscript database

Studies conducted at the USDA Laboratory in Wapato, WA and at Oregon State University were initiated in 2011 to improve the efficacy of an organically-certified formulation of the insecticide spinosad (Entrust®) for control of the spotted wing drosophila, Drosophila suzukii. Our initial approach was...

Protective effect of Geraniol on the transgenic Drosophila model of Parkinson's disease.

PubMed

Siddique, Yasir Hasan; Naz, Falaq; Jyoti, Smita; Ali, Fahad; Fatima, Ambreen; Rahul; Khanam, Saba

2016-04-01

The role of Geraniol was studied on the transgenic Drosophila model flies expressing normal human alpha synuclein (h-αS) in the neurons. Geraniol at final concentration of 10, 20 and 40μM were mixed in the diet and the flies were allowed to feed on it for 24 days. The effect of geraniol was studied on the climbing ability, activity pattern, lipid peroxidation, protein carbonyl, glutathione, dopamine content, and glutathione-S-transferase activity in the brains of transgenic Drosophila. The exposure of PD model flies to 10, 20 and 40μM of geraniol results in a significant delay in the loss of climbing ability (p<0.05), improved activity pattern reduced the oxidative stress (p<0.05) in the brains of transgenic Drosophila as compared to unexposed PD model flies. The results suggest that geraniol is potent in reducing the PD symptoms in transgenic Drosophila model of Parkinson's disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Valeriana officinalis attenuates the rotenone-induced toxicity in Drosophila melanogaster.

PubMed

Sudati, Jéssie Haigert; Vieira, Francielli Araújo; Pavin, Sandra Sartoretto; Dias, Glaecir Roseni Mundstock; Seeger, Rodrigo Lopes; Golombieski, Ronaldo; Athayde, Margareth Linde; Soares, Félix Antunes; Rocha, João Batista Teixeira; Barbosa, Nilda Vargas

2013-07-01

In this study, we investigated the potential protective effects of Valeriana officinalis (V. officinalis) against the toxicity induced by rotenone in Drosophila melanogaster (D. melanogaster). Adult wild-type flies were concomitantly exposed to rotenone (500 μM) and V. officinalis aqueous extract (10mg/mL) in the food during 7 days. Rotenone-fed flies had a worse performance in the negative geotaxis assay (i.e. climbing capability) and open-field test (i.e. mobility time) as well as a higher incidence of mortality when compared to control group. V. officinalis treatment offered protection against these detrimental effects of rotenone. In contrast, the decreased number of crossings observed in the flies exposed to rotenone was not modified by V. officinalis. Rotenone toxicity was also associated with a marked decrease on the total-thiol content in the homogenates and cell viability of flies, which were reduced by V. officinalis treatment. Indeed, rotenone exposure caused a significant increase in the mRNA expression of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) and also in the tyrosine hydroxylase (TH) gene. The expression of SOD and CAT mRNAs was normalized by V. officinalis treatment. Our results suggest that V. officinalis extract was effective in reducing the toxicity induced by rotenone in D. melanogaster as well as confirm the utility of this model to investigate potential therapeutic strategies on movement disorders, including Parkinson disease (PD). Copyright © 2013 Elsevier Inc. All rights reserved.

Drosophila Mitf regulates the V-ATPase and the lysosomal-autophagic pathway.

PubMed

Bouché, Valentina; Espinosa, Alma Perez; Leone, Luigi; Sardiello, Marco; Ballabio, Andrea; Botas, Juan

2016-01-01

An evolutionarily conserved gene network regulates the expression of genes involved in lysosome biogenesis, autophagy, and lipid metabolism. In mammals, TFEB and other members of the MiTF-TFE family of transcription factors control this network. Here we report that the lysosomal-autophagy pathway is controlled by Mitf gene in Drosophila melanogaster. Mitf is the single MiTF-TFE family member in Drosophila and prior to this work was known only for its function in eye development. We show that Mitf regulates the expression of genes encoding V-ATPase subunits as well as many additional genes involved in the lysosomal-autophagy pathway. Reduction of Mitf function leads to abnormal lysosomes and impairs autophagosome fusion and lipid breakdown during the response to starvation. In contrast, elevated Mitf levels increase the number of lysosomes, autophagosomes and autolysosomes, and decrease the size of lipid droplets. Inhibition of Drosophila MTORC1 induces Mitf translocation to the nucleus, underscoring conserved regulatory mechanisms between Drosophila and mammalian systems. Furthermore, we show Mitf-mediated clearance of cytosolic and nuclear expanded ATXN1 (ataxin 1) in a cellular model of spinocerebellar ataxia type 1 (SCA1). This remarkable observation illustrates the potential of the lysosomal-autophagy system to prevent toxic protein aggregation in both the cytoplasmic and nuclear compartments. We anticipate that the genetics of the Drosophila model and the absence of redundant MIT transcription factors will be exploited to investigate the regulation and function of the lysosomal-autophagy gene network.

Transcription Start Site Evolution in Drosophila

PubMed Central

Main, Bradley J.; Smith, Andrew D.; Jang, Hyosik; Nuzhdin, Sergey V.

2013-01-01

Transcription start site (TSS) evolution remains largely undescribed in Drosophila, likely due to limited annotations in non-melanogaster species. In this study, we introduce a concise new method that selectively sequences from the 5′-end of mRNA and used it to identify TSS in four Drosophila species, including Drosophila melanogaster, D. simulans, D. sechellia, and D. pseudoobscura. For verification, we compared our results in D. melanogaster with known annotations, published 5′-rapid amplification of cDNA ends data, and with RNAseq from the same mRNA pool. Then, we paired 2,849 D. melanogaster TSS with its closest equivalent TSS in each species (likely to be its true ortholog) using the available multiple sequence alignments. Most of the D. melanogaster TSSs were successfully paired with an ortholog in each species (83%, 86%, and 55% for D. simulans, D. sechellia, and D. pseudoobscura, respectively). On the basis of the number and distribution of reads mapped at each TSS, we also estimated promoter-specific expression (PSE) and TSS peak shape, respectively. Among paired TSS orthologs, the location and promoter activity were largely conserved. TSS location appears important as PSE, and TSS peak shape was more frequently divergent among TSS that had moved. Unpaired TSS were surprisingly common in D. pseudoobscura. An increased mutation rate upstream of TSS might explain this pattern. We found an enrichment of ribosomal protein genes among diverged TSS, suggesting that TSS evolution is not uniform across the genome. PMID:23649539

A Drosophila Model of Essential Tremor.

PubMed

Smith, Philip; Arias, Ronald; Sonti, Shilpa; Odgerel, Zagaa; Santa-Maria, Ismael; McCabe, Brian D; Tsaneva-Atanasova, Krasimira; Louis, Elan D; Hodge, James J L; Clark, Lorraine N

2018-05-16

Essential Tremor (ET) is one of the most common neurological diseases, with an estimated 7 million affected individuals in the US; the pathophysiology of the disorder is poorly understood. Recently, we identified a mutation (KCNS2 (Kv9.2), c.1137 T > A, p.(D379E) in an electrically silent voltage-gated K + channel α-subunit, Kv9.2, in a family with ET, that modulates the activity of Kv2 channels. We have produced transgenic Drosophila lines that express either the human wild type Kv9.2 (hKv9.2) or the ET causing mutant Kv9.2 (hKv9.2-D379E) subunit in all neurons. We show that the hKv9.2 subunit modulates activity of endogenous Drosophila K + channel Shab. The mutant hKv9.2-D379E subunit showed significantly higher levels of Shab inactivation and a higher frequency of spontaneous firing rate consistent with neuronal hyperexcitibility. We also observed behavioral manifestations of nervous system dysfunction including effects on night time activity and sleep. This functional data further supports the pathogenicity of the KCNS2 (p.D379E) mutation, consistent with our prior observations including co-segregation with ET in a family, a likely pathogenic change in the channel pore domain and absence from population databases. The Drosophila hKv9.2 transgenic model recapitulates several features of ET and may be employed to advance our understanding of ET disease pathogenesis.

Diverse Radiofrequency Sensitivity and Radiofrequency Effects of Mobile or Cordless Phone near Fields Exposure in Drosophila melanogaster

PubMed Central

Geronikolou, Styliani; Zimeras, Stelios; Davos, Constantinos H.; Michalopoulos, Ioannis; Tsitomeneas, Stephanos

2014-01-01

Introduction The impact of electromagnetic fields on health is of increasing scientific interest. The aim of this study was to examine how the Drosophila melanogaster animal model is affected when exposed to portable or mobile phone fields. Methods/Results Two experiments have been designed and performed in the same laboratory conditions. Insect cultures were exposed to the near field of a 2G mobile phone (the GSM 2G networks support and complement in parallel the 3G wide band or in other words the transmission of information via voice signals is served by the 2G technology in both mobile phones generations) and a 1880 MHz cordless phone both digitally modulated by human voice. Comparison with advanced statistics of the egg laying of the second generation exposed and non-exposed cultures showed limited statistical significance for the cordless phone exposed culture and statistical significance for the 900 MHz exposed insects. We calculated by physics, simulated and illustrated in three dimensional figures the calculated near fields of radiation inside the experimenting vials and their difference. Comparison of the power of the two fields showed that the difference between them becomes null when the experimental cylinder radius and the height of the antenna increase. Conclusions/Significance Our results suggest a possible radiofrequency sensitivity difference in insects which may be due to the distance from the antenna or to unexplored intimate factors. Comparing the near fields of the two frequencies bands, we see similar not identical geometry in length and height from the antenna and that lower frequencies tend to drive to increased radiofrequency effects. PMID:25402465

Drosophila Growth Cones Advance by Forward Translocation of the Neuronal Cytoskeletal Meshwork In Vivo

PubMed Central

Roossien, Douglas H.; Lamoureux, Phillip; Van Vactor, David; Miller, Kyle E.

2013-01-01

In vitro studies conducted in Aplysia and chick sensory neurons indicate that in addition to microtubule assembly, long microtubules in the C-domain of the growth cone move forward as a coherent bundle during axonal elongation. Nonetheless, whether this mode of microtubule translocation contributes to growth cone motility in vivo is unknown. To address this question, we turned to the model system Drosophila. Using docked mitochondria as fiduciary markers for the translocation of long microtubules, we first examined motion along the axon to test if the pattern of axonal elongation is conserved between Drosophila and other species in vitro. When Drosophila neurons were cultured on Drosophila extracellular matrix proteins collected from the Drosophila Kc167 cell line, docked mitochondria moved in a pattern indicative of bulk microtubule translocation, similar to that observed in chick sensory neurons grown on laminin. To investigate whether the C-domain is stationary or advances in vivo, we tracked the movement of mitochondria during elongation of the aCC motor neuron in stage 16 Drosophila embryos. We found docked mitochondria moved forward along the axon shaft and in the growth cone C-domain. This work confirms that the physical mechanism of growth cone advance is similar between Drosophila and vertebrate neurons and suggests forward translocation of the microtubule meshwork in the axon underlies the advance of the growth cone C-domain in vivo. These results highlight the need for incorporating en masse microtubule translocation, in addition to assembly, into models of axonal elongation. PMID:24244629

An Autosomal Factor from Drosophila Arizonae Restores Normal Spermatogenesis in Drosophila Mojavensis Males Carrying the D. Arizonae Y Chromosome

PubMed Central

Pantazidis, A. C.; Galanopoulos, V. K.; Zouros, E.

1993-01-01

Males of Drosophila mojavensis whose Y chromosome is replaced by the Y chromosome of the sibling species Drosophila arizonae are sterile. It is shown that genetic material from the fourth chromosome of D. arizonae is necessary and sufficient, in single dose, to restore fertility in these males. In introgression and mapping experiments this material segregates as a single Mendelian factor (sperm motility factor, SMF). Light and electron microscopy studies of spermatogenesis in D. mojavensis males whose Y chromosome is replaced by introgression with the Y chromosome of D. arizonae (these males are symbolized as mojY(a)) revealed postmeiotic abnormalities all of which are restored when the SMF of D. arizonae is co-introgressed (these males are symbolized as mojY(a)SMF(a)). The number of mature sperm per bundle in mojY(a)SMF(a) is slightly less than in pure D. mojavensis and is even smaller in males whose fertility is rescued by introgression of the entire fourth chromosome of D. arizonae. These observations establish an interspecific incompatibility between the Y chromosome and an autosomal factor (or more than one tightly linked factors) that can be useful for the study of the evolution of male hybrid sterility in Drosophila and the genetic control of spermatogenesis. PMID:8514139

Window contamination on Expose-R

NASA Astrophysics Data System (ADS)

Demets, R.; Bertrand, M.; Bolkhovitinov, A.; Bryson, K.; Colas, C.; Cottin, H.; Dettmann, J.; Ehrenfreund, P.; Elsaesser, A.; Jaramillo, E.; Lebert, M.; van Papendrecht, G.; Pereira, C.; Rohr, T.; Saiagh, K.

2015-01-01

Expose is a multi-user instrument for astrobiological and astrochemical experiments in space. Installed at the outer surface of the International Space Station, it enables investigators to study the impact of the open space environment on biological and biochemical test samples. Two Expose missions have been completed so far, designated as Expose-E (Rabbow et al. 2012) and Expose-R (Rabbow et al. this issue). One of the space-unique environmental factors offered by Expose is full-spectrum, ultraviolet (UV)-rich electromagnetic radiation from the Sun. This paper describes and analyses how on Expose-R, access of the test samples to Solar radiation degraded during space exposure in an unpredicted way. Several windows in front of the Sun-exposed test samples acquired a brown shade, resulting in a reduced transparency in visible light, UV and vacuum UV (VUV). Post-flight investigations revealed the discolouration to be caused by a homogenous film of cross-linked organic polymers at the inside of the windows. The chemical signature varied per sample carrier. No such films were found on windows from sealed, pressurized compartments, or on windows that had been kept out of the Sun. This suggests that volatile compounds originating from the interior of the Expose facility were cross-linked and photo-fixed by Solar irradiation at the rear side of the windows. The origin of the volatiles was not fully identified; most probably there was a variety of sources involved including the biological test samples, adhesives, plastics and printed circuit boards. The outer surface of the windows (pointing into space) was chemically impacted as well, with a probable effect on the transparency in VUV. The reported analysis of the window contamination on Expose-R is expected to help the interpretation of the scientific results and offers possibilities to mitigate this problem on future missions - in particular Expose-R2, the direct successor of Expose-R.

Peptidoglycan recognition proteins in Drosophila immunity.

PubMed

Kurata, Shoichiro

2014-01-01

Innate immunity is the front line of self-defense against infectious non-self in vertebrates and invertebrates. The innate immune system is mediated by germ-line encoding pattern recognition molecules (pathogen sensors) that recognize conserved molecular patterns present in the pathogens but absent in the host. Peptidoglycans (PGN) are essential cell wall components of almost all bacteria, except mycoplasma lacking a cell wall, which provides the host immune system an advantage for detecting invading bacteria. Several families of pattern recognition molecules that detect PGN and PGN-derived compounds have been indentified, and the role of PGRP family members in host defense is relatively well-characterized in Drosophila. This review focuses on the role of PGRP family members in the recognition of invading bacteria and the activation and modulation of immune responses in Drosophila. Copyright © 2013 Elsevier Ltd. All rights reserved.

Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila.

PubMed

Silva, Bryon; Molina-Fernández, Claudia; Ugalde, María Beatriz; Tognarelli, Eduardo I; Angel, Cristian; Campusano, Jorge M

2015-01-01

The most studied form of associative learning in Drosophila consists in pairing an odorant, the conditioned stimulus (CS), with an unconditioned stimulus (US). The timely arrival of the CS and US information to a specific Drosophila brain association region, the mushroom bodies (MB), can induce new olfactory memories. Thus, the MB is considered a coincidence detector. It has been shown that olfactory information is conveyed to the MB through cholinergic inputs that activate acetylcholine (ACh) receptors, while the US is encoded by biogenic amine (BA) systems. In recent years, we have advanced our understanding on the specific neural BA pathways and receptors involved in olfactory learning and memory. However, little information exists on the contribution of cholinergic receptors to this process. Here we evaluate for the first time the proposition that, as in mammals, muscarinic ACh receptors (mAChRs) contribute to memory formation in Drosophila. Our results show that pharmacological and genetic blockade of mAChRs in MB disrupts olfactory aversive memory in larvae. This effect is not explained by an alteration in the ability of animals to respond to odorants or to execute motor programs. These results show that mAChRs in MB contribute to generating olfactory memories in Drosophila.

Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila

PubMed Central

Silva, Bryon; Molina-Fernández, Claudia; Ugalde, María Beatriz; Tognarelli, Eduardo I.; Angel, Cristian; Campusano, Jorge M.

2015-01-01

The most studied form of associative learning in Drosophila consists in pairing an odorant, the conditioned stimulus (CS), with an unconditioned stimulus (US). The timely arrival of the CS and US information to a specific Drosophila brain association region, the mushroom bodies (MB), can induce new olfactory memories. Thus, the MB is considered a coincidence detector. It has been shown that olfactory information is conveyed to the MB through cholinergic inputs that activate acetylcholine (ACh) receptors, while the US is encoded by biogenic amine (BA) systems. In recent years, we have advanced our understanding on the specific neural BA pathways and receptors involved in olfactory learning and memory. However, little information exists on the contribution of cholinergic receptors to this process. Here we evaluate for the first time the proposition that, as in mammals, muscarinic ACh receptors (mAChRs) contribute to memory formation in Drosophila. Our results show that pharmacological and genetic blockade of mAChRs in MB disrupts olfactory aversive memory in larvae. This effect is not explained by an alteration in the ability of animals to respond to odorants or to execute motor programs. These results show that mAChRs in MB contribute to generating olfactory memories in Drosophila. PMID:26380118

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

PubMed

Stephenson, R; Metcalfe, N H

2013-01-01

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

Species and genetic diversity in the genus Drosophila inhabiting the Indian subcontinent.

PubMed

Singh, Bashisth N

2015-06-01

Biodiversity is the sum total of all living things on the earth with particular reference to the profound variety in structure,function and genetic constitution. It includes both number and frequency of species or genes in a given assemblage and the variety of resulting ecosystems in a region. It is usually considered at three different levels: genetic, species and ecological diversities. Genus Drosophila belongs to the family Drosophilidae (class Insecta, order Diptera), characterized by rich species diversity at global level and also in India, which is a megadiverse country. At global level, more than 1500 species have been described and several thousands estimated. Hawaiian Islands are particularly rich in species diversity with more than 500 species which provides a unique opportunity to study evolution in genus Drosophila. About 150 species of Drosophila have been reported from India. Certain species of Drosophila found in India have been investigated for genetic diversity within the species. In this regard, Drosophila ananassae is noteworthy. It is a cosmopolitan and domestic species with common occurrence in India and is endowed with many genetic peculiarities. Population genetics and evolutionary studies in this species have revealed as to how genetic diversity within a species play an important role in adaptation of populations to varying environments. In addition, the work carried on D. melanogaster, D. nasuta, D. bipectinata and certain other species in India has shown that these species vary in degree and pattern of genetic diversity, and have evolved different mechanisms for adjusting to their environments. The ecological adaptations to various kinds of stress studied in certain species of Drosophila inhabiting the Indian subcontinent are also discussed.

High rate of translocation-based gene birth on the Drosophila Y chromosome.

PubMed

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 (<1 million years old), only three showed evidence for purifying selection ( ω ≤ 0.14). Thus, although the resulting Y-linked functional gene acquisition rate (0.25 new genes per million years) is double the longer-term estimate, the fate of most new Y-linked genes is defined by rapid degeneration and pseudogenization. Our results show that Y-linked gene traffic, and the molecular mechanisms governing these transfers, can diverge rapidly between species, revealing the 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.

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

PubMed Central

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

2016-01-01

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

Mapping Second Chromosome Mutations to Defined Genomic Regions in Drosophila melanogaster

PubMed Central

Kahsai, Lily; Cook, Kevin R.

2017-01-01

Hundreds of Drosophila melanogaster stocks are currently maintained at the Bloomington Drosophila Stock Center with mutations that have not been associated with sequence-defined genes. They have been preserved because they have interesting loss-of-function phenotypes. The experimental value of these mutations would be increased by tying them to specific genomic intervals so that geneticists can more easily associate them with annotated genes. Here, we report the mapping of 85 second chromosome complementation groups in the Bloomington collection to specific, small clusters of contiguous genes or individual genes in the sequenced genome. This information should prove valuable to Drosophila geneticists interested in processes associated with particular phenotypes and those searching for mutations affecting specific sequence-defined genes. PMID:29066472

Bone pain caused by swelling of mouse ear capsule static xylene and effects on rat models of cervical spondylosis

NASA Astrophysics Data System (ADS)

Zhang, Xuhui; Xia, Lei; Hao, Shaojun; Chen, Weiliang; Guo, Junyi; Ma, Zhenzhen; Wang, Huamin; Kong, Xuejun; Wang, Hongyu; Zhang, Zhengchen

2018-04-01

To observe the effect of intravenous bone pain Capsule on the ear of mice induced by xylene, swelling of rat models of cervical spondylosis. Weighing 18 ˜ 21g 50 mice, male, were randomly divided into for five groups, which were fed with service for bone pain static capsule suspension, Jingfukang granule suspension 0.5%CMC liquid and the same volume of. Respectively to the mice ear drop of xylene 0.05 ml, 4h after cervical dislocation, the mice were sacrificed and the cut two ear, rapid analytical balance weighing, and calculate the ear swelling degree and the other to take the weight of 200 - 60 250g male SD rats, were randomly divided into for 6 groups, 10 rats in each group, of which 5 groups made cervical spondylosis model. Results: with the blank group than bone pain static capsule group and Jingfukang granule group can significantly reduce mouse auricular dimethylbenzene swelling, significantly reduce ear swelling degree (P < 0.01); the successful establishment of the rat model of cervical spondylosis. With the model group ratio, large, medium and small dose of bone pain static capsule group, Jingfukang granule group (P < 0.01) angle of swash plate of rats increased significantly, the high and middle dose of bone pain static capsule group, Jingfukang granule group can significantly reduce the rat X-ray scores (P < 0.05). Bone pain static capsule can significantly reduce mouse auricular dimethylbenzene swelling. The bone pain capsule has a good effect on the rat model of cervical spondylosis.

Drosophila Cajal bodies: accessories not included

PubMed Central

Matera, A. Gregory

2006-01-01

Cajal bodies are nuclear sites of small ribonucleoprotein (RNP) remodeling and maturation. A recent study describes the discovery of the Drosophila Cajal body, revealing some interesting insights into the subnuclear organization of RNA processing machineries among different species. PMID:16533940

Comprehensive functional analysis of Rab GTPases in Drosophila nephrocytes.

PubMed

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.

The ecology of the Drosophila-yeast mutualism in wineries

PubMed Central

2018-01-01

The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila. PMID:29768432

The ecology of the Drosophila-yeast mutualism in wineries.

PubMed

Quan, Allison S; Eisen, Michael B

2018-01-01

The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila.

The Drosophila serpins: multiple functions in immunity and morphogenesis.

PubMed

Reichhart, Jean Marc; Gubb, David; Leclerc, Vincent

2011-01-01

Members of the serpin superfamily of proteins have been found in all living organisms, although rarely in bacteria or fungi. They have been extensively studied in mammals, where many rapid physiological responses are regulated by inhibitory serpins. In addition to the inhibitory serpins, a large group of noninhibitory proteins with a conserved serpin fold have also been identified in mammals. These noninhibitory proteins have a wide range of functions, from storage proteins to molecular chaperones, hormone transporters, and tumor suppressors. In contrast, until recently, very little was known about insect serpins in general, or Drosophila serpins in particular. In the last decade, however, there has been an increasing interest in the serpin biology of insects. It is becoming clear that, like in mammals, a similar wide range of physiological responses are regulated in insects and that noninhibitory serpin-fold proteins also play key roles in insect biology. Drosophila is also an important model organism that can be used to study human pathologies (among which serpinopathies or other protein conformational diseases) and mechanisms of regulation of proteolytic cascades in health or to develop strategies for control of insect pests and disease vectors. As most of our knowledge on insect serpins comes from studies on the Drosophila immune response, we survey here the Drosophila serpin literature and describe the laboratory techniques that have been developed to study serpin-regulated responses in this model genetic organism. Copyright © 2011 Elsevier Inc. All rights reserved.

CASK and CaMKII function in Drosophila memory

PubMed Central

Malik, Bilal R.; Hodge, James J. L.

2014-01-01

Calcium (Ca2+) and Calmodulin (CaM)-dependent serine/threonine kinase II (CaMKII) plays a central role in synaptic plasticity and memory due to its ability to phosphorylate itself and regulate its own kinase activity. Autophosphorylation at threonine 287 (T287) switches CaMKII to a Ca2+ independent and constitutively active state replicated by overexpression of a phosphomimetic CaMKII-T287D transgene or blocked by expression of a T287A transgene. A second pair of sites, T306 T307 in the CaM binding region once autophosphorylated, prevents CaM binding and inactivates the kinase during synaptic plasticity and memory, and can be blocked by a TT306/7AA transgene. Recently the synaptic scaffolding molecule called CASK (Ca2+/CaM-associated serine kinase) has been shown to control both sets of CaMKII autophosphorylation events during neuronal growth, Ca2+ signaling and memory in Drosophila. Deletion of either full length CASK or just its CaMK-like and L27 domains removed middle-term memory (MTM) and long-term memory (LTM), with CASK function in the α′/ß′ mushroom body neurons being required for memory. In a similar manner directly changing the levels of CaMKII autophosphorylation (T287D, T287A, or TT306/7AA) in the α′/ß′ neurons also removed MTM and LTM. In the CASK null mutant expression of either the Drosophila or human CASK transgene in the α′/ß′ neurons was found to completely rescue memory, confirming that CASK signaling in α′/β′ neurons is necessary and sufficient for Drosophila memory formation and that the neuronal function of CASK is conserved between Drosophila and human. Expression of human CASK in Drosophila also rescued the effect of CASK deletion on the activity state of CaMKII, suggesting that human CASK may also regulate CaMKII autophosphorylation. Mutations in human CASK have recently been shown to result in intellectual disability and neurological defects suggesting a role in plasticity and learning possibly via regulation of Ca

Drosophila VAMP7 regulates Wingless intracellular trafficking.

PubMed

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.

Overview of Drosophila immunity: a historical perspective.

PubMed

Imler, Jean-Luc

2014-01-01

The functional analysis of genes from the model organism Drosophila melanogaster has provided invaluable information for many cellular and developmental or physiological processes, including immunity. The best-understood aspect of Drosophila immunity is the inducible humoral response, first recognized in 1972. This pioneering work led to a remarkable series of findings over the next 30 years, ranging from the identification and characterization of the antimicrobial peptides produced, to the deciphering of the signalling pathways activating the genes that encode them and, ultimately, to the discovery of the receptors sensing infection. These studies on an insect model coincided with a revival of the field of innate immunity, and had an unanticipated impact on the biomedical field. Copyright © 2013 Elsevier Ltd. All rights reserved.

The fabulous destiny of the Drosophila heart.

PubMed

Medioni, Caroline; Sénatore, Sébastien; Salmand, Pierre-Adrien; Lalevée, Nathalie; Perrin, Laurent; Sémériva, Michel

2009-10-01

For the last 15 years the fly cardiovascular system has attracted developmental geneticists for its potential as a model system of organogenesis. Heart development in Drosophila indeed provides a remarkable system for elucidating the basic molecular and cellular mechanisms of morphogenesis and, more recently, for understanding the genetic control of cardiac physiology. The success of these studies can in part be attributed to multidisciplinary approaches, the multiplicity of existing genetic tools, and a detailed knowledge of the system. Striking similarities with vertebrate cardiogenesis have long been stressed, in particular concerning the conservation of key molecular regulators of cardiogenesis and the new data presented here confirm Drosophila cardiogenesis as a model not only for organogenesis but also for the study of molecular mechanisms of human cardiac disease.

The genetics of behavioral alcohol responses in Drosophila.

PubMed

Rodan, Aylin R; Rothenfluh, Adrian

2010-01-01

Drosophila melanogaster is commonly found near rotting or fermenting fruit, reflected in its name pomace, or vinegar fly. In such environments, flies often encounter significant levels of ethanol. Three observations have made Drosophila a very promising model organism to understand the genetic contributions to the behavioral responses to alcohol. First, similar to higher vertebrates, flies show hyperactivation upon exposure to a low to medium dose of alcohol, while high doses can lead to sedation. In addition, when given a choice, flies will actually prefer alcohol-containing food over regular food. Second, the genes and biochemical pathways implicated in controlling these behavioral responses in flies are also participating in determining alcohol responses, and drinking behavior in mammals. Third, the fact that flies have been studied genetically for over one hundred years means that an exceptional repertoire of genetic tools are at our disposal. Here, we will review some of these tools and experimental approaches, survey the methods for, and measures after Drosophila ethanol exposure, and discuss the different molecular components and functional pathways involved in these behavioral responses to alcohol. Copyright 2010 Elsevier Inc. All rights reserved.

Analysis of the interaction between human RITA and Drosophila Suppressor of Hairless.

PubMed

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.

Life History Traits of an Extended Longevity Phenotype of Drosophila melanogaster.

PubMed

Deepashree, S; Shivanandappa, T; Ramesh, S R

2017-01-01

Aging or senescence is a complex biological phenomenon. Artificially selected Drosophila for extended longevity is one of the experimental models used to understand the mechanisms involved in aging and to test various theories. To examine the life history traits and biochemical defenses in relation to aging in an extended longevity phenotype of Drosophila melanogaster. Life history traits viz., survivability, fecundity, development time, dry weight, wing size, lipid content, starvation, desiccation and cold resistances, locomotory ability, antioxidant enzyme activities and reactive oxygen species level between control and selected lines of D. melanogaster were investigated. In our model of Drosophila, extended longevity is associated with no trade-off in fecundity and shows variable resistance to environmental stress such as starvation, cold and desiccation. Enhanced biochemical defense involving the antioxidant enzymes was positively correlated with longevity. Extended longevity phenotypes of Drosophila represent genomic plasticity associated with variable life history traits attributed to the genetic background of the progenitor population and the environment of selection. Oxidative stress resistance seems to be a significant factor in longevity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Dyeing Insects for Behavioral Assays: the Mating Behavior of Anesthetized Drosophila

PubMed Central

Verspoor, Rudi L.; Heys, Chloe; Price, Thomas A. R.

2015-01-01

Mating experiments using Drosophila have contributed greatly to the understanding of sexual selection and behavior. Experiments often require simple, easy and cheap methods to distinguish between individuals in a trial. A standard technique for this is CO2 anaesthesia and then labelling or wing clipping each fly. However, this is invasive and has been shown to affect behavior. Other techniques have used coloration to identify flies. This article presents a simple and non-invasive method for labelling Drosophila that allows them to be individually identified within experiments, using food coloring. This method is used in trials where two males compete to mate with a female. Dyeing allowed quick and easy identification. There was, however, some difference in the strength of the coloration across the three species tested. Data is presented showing the dye has a lower impact on mating behavior than CO2 in Drosophila melanogaster. The impact of CO2 anaesthesia is shown to depend on the species of Drosophila, with D. pseudoobscura and D. subobscura showing no impact, whereas D. melanogaster males had reduced mating success. The dye method presented is applicable to a wide range of experimental designs. PMID:25938821

Conditioning to colors: a population assay for visual learning in Drosophila.

PubMed

van Swinderen, Bruno

2011-11-01

Vision is a major sensory modality in Drosophila behavior, with more than one-half of the Drosophila brain devoted to visual processing. The mechanisms of vision in Drosophila can be studied in individuals and in populations of flies by using various paradigms. Although there has never been a widely used population assay for visual learning in Drosophila, some population paradigms have shown significant visual learning. These studies use colors as conditioned stimuli (CS) and shaking as the unconditioned stimulus (US). A simple version of the paradigm, conditioning to colors using a shaking device, is described here. A conditioning chamber, called a crab, is designed to center the flies after shaking by having them tumble down to the lowest point between joined glass tubes forming a V. Thus, vibration should be just strong enough to center most flies. After shaking, flies display a geotactic response and climb up either side of the V, and their choice of which side to climb is influenced by color displays on either side. The proportion of flies on either side determines the flies' natural preference or their learned avoidance of a color associated with shaking.

Protein Equilibration through Somatic Ring Canals in Drosophila

PubMed Central

McLean, Peter F.; Cooley, Lynn

2013-01-01

Although intercellular bridges resulting from incomplete cytokinesis were discovered in somatic Drosophila tissues decades ago, the impact of these structures on intercellular communication and tissue biology is largely unknown. In this work, we demonstrate that the ~250 nm diameter somatic ring canals permit diffusion of cytoplasmic contents between connected cells and across mitotic clone boundaries, and enable the equilibration of protein between transcriptionally mosaic follicle cells in the Drosophila ovary. We obtained similar, though more restricted, results in the larval imaginal discs. Our work illustrates the lack of cytoplasmic autonomy in these tissues and suggests a role for somatic ring canals in promoting homogeneous protein expression within the tissue. PMID:23704373

Tracing the tracks of genotoxicity by trivalent and hexavalent chromium in Drosophila melanogaster.

PubMed

Mishra, Manish; Sharma, Anurag; Negi, M P S; Dwivedi, U N; Chowdhuri, D Kar

2011-05-18

Mutagen sensitive strains (mus) in Drosophila are known for their hypersensitivity to mutagens and environmental carcinogens. Accordingly, these mutants were grouped in pre- and post-replication repair pathways. However, studying mutants belonging to one particular repair pathway may not be adequate for examining chemical-induced genotoxicity when other repair pathways may neutralize its effect. To test whether both pre-and post-replication pathways are involved and effect of Cr(III)- and Cr(VI)-induced genotoxicity in absence or presence of others, we used double mutant approach in D. melanogaster. We observed DNA damage as evident by changes in Comet assay DNA migration in cells of larvae of Oregon R(+) and single mutants of pre- (mei-9, mus201 and mus210) and post- (mei-41, mus209 and mus309) replication repair pathways and also in double mutants of different combinations (pre-pre, pre-post and post-post replication repair) exposed to increasing concentrations of Cr(VI) (0.0, 5.0, 10.0 and 20.0 μg/ml) for 48 h. The damage was greater in pre-replication repair mutants after exposure to 5.0 μg/ml Cr(VI), while effects on Oregon R(+) and post replication repair mutants were insignificant. Post-replication repair mutants revealed significant DNA damage after exposure to 20.0 μg/ml Cr(VI). Further, double mutants generated in the above repair categories were examined for DNA damage following Cr(VI) exposure and a comparison of damage was studied between single and double mutants. Combinations of double mutants generated in the pre-pre replication repair pathways showed an indifferent interaction between the two mutants after Cr(VI) exposure while a synergistic interaction was evident in exposed post-post replication repair double mutants. Cr(III) (20.0 μg/ml) exposure to these strains did not induce any significant DNA damage in their cells. The study suggests that both pre- and post-replication pathways are affected in Drosophila by Cr(VI) leading to

Visual Pattern Memory Requires "Foraging" Function in the Central Complex of "Drosophila"

ERIC Educational Resources Information Center

Wang, Zhipeng; Pan, Yufeng; Li, Weizhe; Jiang, Huoqing; Chatzimanolis, Lazaros; Chang, Jianhong; Gong, Zhefeng; Liu, Li

2008-01-01

The role of the "foraging" ("for)" gene, which encodes a cyclic guanosine-3',5'-monophosphate (cGMP)-dependent protein kinase (PKG), in food-search behavior in "Drosophila" has been intensively studied. However, its functions in other complex behaviors have not been well-characterized. Here, we show experimentally in "Drosophila" that the "for"…

How Hot Are Drosophila Hotspots? Examining Recombination Rate Variation and Associations with Nucleotide Diversity, Divergence, and Maternal Age in Drosophila pseudoobscura

PubMed Central

Manzano-Winkler, Brenda; McGaugh, Suzanne E.; Noor, Mohamed A. F.

2013-01-01

Fine scale meiotic recombination maps have uncovered a large amount of variation in crossover rate across the genomes of many species, and such variation in mammalian and yeast genomes is concentrated to <5kb regions of highly elevated recombination rates (10–100x the background rate) called “hotspots.” Drosophila exhibit substantial recombination rate heterogeneity across their genome, but evidence for these highly-localized hotspots is lacking. We assayed recombination across a 40Kb region of Drosophila pseudoobscura chromosome 2, with one 20kb interval assayed every 5Kb and the adjacent 20kb interval bisected into 10kb pieces. We found that recombination events across the 40kb stretch were relatively evenly distributed across each of the 5kb and 10kb intervals, rather than concentrated in a single 5kb region. This, in combination with other recent work, indicates that the recombination landscape of Drosophila may differ from the punctate recombination pattern observed in many mammals and yeast. Additionally, we found no correlation of average pairwise nucleotide diversity and divergence with recombination rate across the 20kb intervals, nor any effect of maternal age in weeks on recombination rate in our sample. PMID:23967224

Evolutionary optimality applied to Drosophila experiments: hypothesis of constrained reproductive efficiency.

PubMed

Novoseltsev, V N; Arking, R; Novoseltseva, J A; Yashin, A I

2002-06-01

The general purpose of the paper is to test evolutionary optimality theories with experimental data on reproduction, energy consumption, and longevity in a particular Drosophila genotype. We describe the resource allocation in Drosophila females in terms of the oxygen consumption rates devoted to reproduction and to maintenance. The maximum ratio of the component spent on reproduction to the total rate of oxygen consumption, which can be realized by the female reproductive machinery, is called metabolic reproductive efficiency (MRE). We regard MRE as an evolutionary constraint. We demonstrate that MRE may be evaluated for a particular Drosophila phenotype given the fecundity pattern, the age-related pattern of oxygen consumption rate, and the longevity. We use a homeostatic model of aging to simulate a life history of a representative female fly, which describes the control strain in the long-term experiments with the Wayne State Drosophila genotype. We evaluate the theoretically optimal trade-offs in this genotype. Then we apply the Van Noordwijk-de Jong resource acquisition and allocation model, Kirkwood's disposable soma theory. and the Partridge-Barton optimality approach to test if the experimentally observed trade-offs may be regarded as close to the theoretically optimal ones. We demonstrate that the two approaches by Partridge-Barton and Kirkwood allow a positive answer to the question, whereas the Van Noordwijk-de Jong approach may be used to illustrate the optimality. We discuss the prospects of applying the proposed technique to various Drosophila experiments, in particular those including manipulations affecting fecundity.

Increased centrosome amplification in aged stem cells of the Drosophila midgut

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Joung-Sun; Pyo, Jung-Hoon; Na, Hyun-Jin

Highlights: • Increased centrosome amplification in ISCs of aged Drosophila midguts. • Increased centrosome amplification in ISCs of oxidative stressed Drosophila midguts. • Increased centrosome amplification in ISCs by overexpression of PVR, EGFR, and AKT. • Supernumerary centrosomes can be responsible for abnormal ISC polyploid cells. • Supernumerary centrosomes can be a useful marker for aging stem cells. - Abstract: Age-related changes in long-lived tissue-resident stem cells may be tightly linked to aging and age-related diseases such as cancer. Centrosomes play key roles in cell proliferation, differentiation and migration. Supernumerary centrosomes are known to be an early event in tumorigenesismore » and senescence. However, the age-related changes of centrosome duplication in tissue-resident stem cells in vivo remain unknown. Here, using anti-γ-tubulin and anti-PH3, we analyzed mitotic intestinal stem cells with supernumerary centrosomes in the adult Drosophila midgut, which may be a versatile model system for stem cell biology. The results showed increased centrosome amplification in intestinal stem cells of aged and oxidatively stressed Drosophila midguts. Increased centrosome amplification was detected by overexpression of PVR, EGFR, and AKT in intestinal stem cells/enteroblasts, known to mimic age-related changes including hyperproliferation of intestinal stem cells and hyperplasia in the midgut. Our data show the first direct evidence for the age-related increase of centrosome amplification in intestinal stem cells and suggest that the Drosophila midgut is an excellent model for studying molecular mechanisms underlying centrosome amplification in aging adult stem cells in vivo.« less

Generating Germ-Free Drosophila to Study Gut-Microbe Interactions: Protocol to Rear Drosophila Under Axenic Conditions.

PubMed

Kietz, Christa; Pollari, Vilma; Meinander, Annika

2018-06-22

As several diseases have been linked to dysbiosis of the human intestinal microflora, manipulation of the microbiota has emerged as an exciting new strategy for potentially treating and preventing diseases. However, the human microbiota consists of a plethora of different species, and distinguishing the impact of a specific bacterial species on human health is challenging. In tackling this challenge, the fruit fly Drosophila melanogaster, with its far simpler microbial composition, has emerged as a powerful model for unraveling host-microbe interactions. To study the interplay between the resident commensal microbiome and the host, flies can be made germ-free, or axenic. To elucidate the impact of specific bacteria, axenic flies can then be re-introduced to specific microbial species. In this unit, we provide a step-by-step protocol on how to rear Drosophila melanogaster under axenic conditions and confirm the axenity of flies. © 2018 by John Wiley & Sons, Inc. © 2018 John Wiley & Sons, Inc.

Effect of explosion-puffed coffee on locomotor activity and behavioral patterns in Drosophila melanogaster.

PubMed

Ko, Bong Soo; Ahn, So Hyun; Noh, Dong Ouk; Hong, Ki-Bae; Han, Sung Hee; Suh, Hyung Joo

2017-10-01

the underlying mechanism of the behavioral change patterns of explosive puffed with or without caffeine in Drosophila models, transcript level for the Dop1-R1 receptor in caffeine group was significantly higher than normal, PB, and DePB groups. Flies exposed to the caffeine had significantly decreased transcript levels for the GABA receptors. PB 7.5 and DePB showed higher level of GABA content than RB. Copyright © 2017 Elsevier Ltd. All rights reserved.

Longevity-modulating effects of symbiosis: insights from Drosophila-Wolbachia interaction.

PubMed

Maistrenko, Oleksandr M; Serga, Svitlana V; Vaiserman, Alexander M; Kozeretska, Iryna A

2016-11-01

Microbial communities are known to significantly affect various fitness components and survival of their insect hosts, including Drosophila. The composition of symbiotic microbiota has been shown to change with the host's aging. It is unclear whether these changes are caused by the aging process or, vice versa, they affect the host's aging and longevity. Recent findings indicate that fitness and lifespan of Drosophila are affected by endosymbiotic bacteria Wolbachia. These effects, however, are inconsistent and have been reported both to extend and shorten longevity. The main molecular pathways underlying the lifespan-modulating effects of Wolbachia remain unclear, however insulin/insulin-like growth factor, immune deficiency, ecdysteroid synthesis and signaling and c-Jun N-terminal kinase pathways as well as heat shock protein synthesis and autophagy have been proposed to play a role. Here we revise the current evidence that elucidates the impact of Wolbachia endosymbionts on the aging processes in Drosophila.

Identification and functional characterization of muscle satellite cells in Drosophila

PubMed Central

Reichert, Heinrich

2017-01-01

Work on genetic model systems such as Drosophila and mouse has shown that the fundamental mechanisms of myogenesis are remarkably similar in vertebrates and invertebrates. Strikingly, however, satellite cells, the adult muscle stem cells that are essential for the regeneration of damaged muscles in vertebrates, have not been reported in invertebrates. In this study, we show that lineal descendants of muscle stem cells are present in adult muscle of Drosophila as small, unfused cells observed at the surface and in close proximity to the mature muscle fibers. Normally quiescent, following muscle fiber injury, we show that these cells express Zfh1 and engage in Notch-Delta-dependent proliferative activity and generate lineal descendant populations, which fuse with the injured muscle fiber. In view of strikingly similar morphological and functional features, we consider these novel cells to be the Drosophila equivalent of vertebrate muscle satellite cells. PMID:29072161

Predatory cannibalism in Drosophila melanogaster larvae.

PubMed

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

2013-01-01

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

The translation factors of Drosophila melanogaster.

PubMed

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

2017-01-02

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

Modification of CO2 avoidance behaviour in Drosophila by inhibitory odorants.

PubMed

Turner, Stephanie Lynn; Ray, Anandasankar

2009-09-10

The fruitfly Drosophila melanogaster exhibits a robust and innate olfactory-based avoidance behaviour to CO(2), a component of odour emitted from stressed flies. Specialized neurons in the antenna and a dedicated neuronal circuit in the higher olfactory system mediate CO(2) detection and avoidance. However, fruitflies need to overcome this avoidance response in some environments that contain CO(2) such as ripening fruits and fermenting yeast, which are essential food sources. Very little is known about the molecular and neuronal basis of this unique, context-dependent modification of innate olfactory avoidance behaviour. Here we identify a new class of odorants present in food that directly inhibit CO(2)-sensitive neurons in the antenna. Using an in vivo expression system we establish that the odorants act on the Gr21a/Gr63a CO(2) receptor. The presence of these odorants significantly and specifically reduces CO(2)-mediated avoidance behaviour, as well as avoidance mediated by 'Drosophila stress odour'. We propose a model in which behavioural avoidance to CO(2) is directly influenced by inhibitory interactions of the novel odours with CO(2) receptors. Furthermore, we observe differences in the temporal dynamics of inhibition: the effect of one of these odorants lasts several minutes beyond the initial exposure. Notably, animals that have been briefly pre-exposed to this odorant do not respond to the CO(2) avoidance cue even after the odorant is no longer present. We also show that related odorants are effective inhibitors of the CO(2) response in Culex mosquitoes that transmit West Nile fever and filariasis. Our findings have broader implications in highlighting the important role of inhibitory odorants in olfactory coding, and in their potential to disrupt CO(2)-mediated host-seeking behaviour in disease-carrying insects like mosquitoes.

Differentiation of Drosophila glial cells.

PubMed

Sasse, Sofia; Neuert, Helen; Klämbt, Christian

2015-01-01

Glial cells are important constituents of the nervous system and a hallmark of these cells are their pronounced migratory abilities. In Drosophila, glial lineages have been well described and some of the molecular mechanisms necessary to guide migrating glial cells to their final target sites have been identified. With the onset of migration, glial cells are already specified into one of five main glial cell types. The perineurial and subperineurial glial cells are eventually located at the outer surface of the Drosophila nervous system and constitute the blood-brain barrier. The cortex glial cells ensheath all neuroblasts and their progeny and reside within the central nervous system. Astrocyte-like cells invade the neuropil to control synaptic function and ensheathing glial cells encase the entire neuropil. Within the peripheral nervous system, wrapping glial cells ensheath individual axons or axon fascicles. Here, we summarize the current knowledge on how differentiation of glial cells into the specific subtypes is orchestrated. Furthermore, we discuss sequencing data that will facilitate further analyses of glial differentiation in the fly nervous system. © 2015 Wiley Periodicals, Inc.

Evidence for a Complex Class of Nonadenylated mRNA in Drosophila

PubMed Central

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

Transcriptional regulation of xenobiotic detoxification in Drosophila

PubMed Central

Misra, Jyoti R.; Horner, Michael A.; Lam, Geanette; Thummel, Carl S.

2011-01-01

Living organisms, from bacteria to humans, display a coordinated transcriptional response to xenobiotic exposure, inducing enzymes and transporters that facilitate detoxification. Several transcription factors have been identified in vertebrates that contribute to this regulatory response. In contrast, little is known about this pathway in insects. Here we show that the Drosophila Nrf2 (NF-E2-related factor 2) ortholog CncC (cap ‘n’ collar isoform-C) is a central regulator of xenobiotic detoxification responses. A binding site for CncC and its heterodimer partner Maf (muscle aponeurosis fibromatosis) is sufficient and necessary for robust transcriptional responses to three xenobiotic compounds: phenobarbital (PB), chlorpromazine, and caffeine. Genetic manipulations that alter the levels of CncC or its negative regulator, Keap1 (Kelch-like ECH-associated protein 1), lead to predictable changes in xenobiotic-inducible gene expression. Transcriptional profiling studies reveal that more than half of the genes regulated by PB are also controlled by CncC. Consistent with these effects on detoxification gene expression, activation of the CncC/Keap1 pathway in Drosophila is sufficient to confer resistance to the lethal effects of the pesticide malathion. These studies establish a molecular mechanism for the regulation of xenobiotic detoxification in Drosophila and have implications for controlling insect populations and the spread of insect-borne human diseases. PMID:21896655

Peroxiredoxin 5 confers protection against oxidative stress and apoptosis and also promotes longevity in Drosophila

PubMed Central

Radyuk, Svetlana N.; Michalak, Katarzyna; Klichko, Vladimir I.; Benes, Judith; Rebrin, Igor; Sohal, Rajindar S.; Orr, William C.

2010-01-01

Peroxiredoxin 5 is a distinct isoform of the peroxiredoxin gene family. The antioxidative and anti-apoptotic functions of peroxiredoxin 5 have been extensively demonstrated in cell culture experiments. In the present paper, we provide the first functional analysis of peroxiredoxin 5 in a multicellular organism, Drosophila melanogaster. Similar to its mammalian, yeast or human counterparts, dPrx5 (Drosophila peroxiredoxin 5) is expressed in several cellular compartments, including the cytosol, nucleus and the mitochondrion. Global overexpression of dPrx5 in flies increased resistance to oxidative stress and extended their life span by up to 30% under normal conditions. The dprx5−/− null flies were comparatively more susceptible to oxidative stress, had higher incidence of apoptosis, and a shortened life span. TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) analysis revealed that the dprx5−/− null mutant had discernible tissue-specific apoptotic patterns, similar to those observed in control flies exposed to paraquat. In addition, apoptosis was particularly notable in oenocytes. During development the dPrx5 levels co-varied with ecdysone pulses, suggesting inter-relationship between ecdystreroids and dPrx5 expression. The importance of dPrx5 for development was further underscored by the embryonic lethal phenotype of progeny derived from the dprx5−/− null mutant. Results from the present study suggest that the antioxidant and anti-apoptotic activities of dPrx5 play a critical role in development and aging of the fly. PMID:19128239

mus304 encodes a novel DNA damage checkpoint protein required during Drosophila development

PubMed Central

Brodsky, Michael H.; Sekelsky, Jeff J.; Tsang, Garson; Hawley, R. Scott; Rubin, Gerald M.

2000-01-01

Checkpoints block cell cycle progression in eukaryotic cells exposed to DNA damaging agents. We show that several Drosophila homologs of checkpoint genes, mei-41, grapes, and 14-3-3ε, regulate a DNA damage checkpoint in the developing eye. We have used this assay to show that the mutagen-sensitive gene mus304 is also required for this checkpoint. mus304 encodes a novel coiled-coil domain protein, which is targeted to the cytoplasm. Similar to mei-41, mus304 is required for chromosome break repair and for genomic stability. mus304 animals also exhibit three developmental defects, abnormal bristle morphology, decreased meiotic recombination, and arrested embryonic development. We suggest that these phenotypes reflect distinct developmental consequences of a single underlying checkpoint defect. Similar mechanisms may account for the puzzling array of symptoms observed in humans with mutations in the ATM tumor suppressor gene. PMID:10733527

Odor-Evoked Inhibition of Olfactory Sensory Neurons Drives Olfactory Perception in Drosophila

DTIC Science & Technology

2017-05-22

J.L. Highly efficient targeted 859 mutagenesis of Drosophila with the CRISPR /Cas9 system. Cell Rep. 4, 220-228 860 (2013). 861 53. Gratz, S.J...Harrison, M.M., Wildonger, J. & O’Connor-Giles, K.M. Precise 862 Genome Editing of Drosophila with CRISPR RNA-Guided Cas9. Methods Mol. 863 Biol. 1311

Spotted Wing Drosophila, Sparganothis phenology and a new look at the BugFloods

USDA-ARS?s Scientific Manuscript database

Drosophila suzukii, commonly known as spotted wing drosophila (SWD), does not readily oviposit in cranberries. Following multiple replicated trials using ripe, under-ripe, and over-ripe organic Wisconsin cranberries, SWD females would not (or could not) insert eggs into under-ripe or ripe cranberrie...

Gene Regulation Networks for Modeling Drosophila Development

NASA Technical Reports Server (NTRS)

Mjolsness, E.

1999-01-01

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

Drosophila Protein Kinase CK2: Genetics, Regulatory Complexity and Emerging Roles during Development

PubMed Central

Bandyopadhyay, Mohna; Arbet, Scott; Bishop, Clifton P.; Bidwai, Ashok P.

2016-01-01

CK2 is a Ser/Thr protein kinase that is highly conserved amongst all eukaryotes. It is a well-known oncogenic kinase that regulates vital cell autonomous functions and animal development. Genetic studies in the fruit fly Drosophila are providing unique insights into the roles of CK2 in cell signaling, embryogenesis, organogenesis, neurogenesis, and the circadian clock, and are revealing hitherto unknown complexities in CK2 functions and regulation. Here, we review Drosophila CK2 with respect to its structure, subunit diversity, potential mechanisms of regulation, developmental abnormalities linked to mutations in the gene encoding CK2 subunits, and emerging roles in multiple aspects of eye development. We examine the Drosophila CK2 “interaction map” and the eye-specific “transcriptome” databases, which raise the prospect that this protein kinase has many additional targets in the developing eye. We discuss the possibility that CK2 functions during early retinal neurogenesis in Drosophila and mammals bear greater similarity than has been recognized, and that this conservation may extend to other developmental programs. Together, these studies underscore the immense power of the Drosophila model organism to provide new insights and avenues to further investigate developmentally relevant targets of this protein kinase. PMID:28036067

Dissecting social cell biology and tumors using Drosophila genetics.

PubMed

Pastor-Pareja, José Carlos; Xu, Tian

2013-01-01

Cancer was seen for a long time as a strictly cell-autonomous process in which oncogenes and tumor-suppressor mutations drive clonal cell expansions. Research in the past decade, however, paints a more integrative picture of communication and interplay between neighboring cells in tissues. It is increasingly clear as well that tumors, far from being homogenous lumps of cells, consist of different cell types that function together as complex tissue-level communities. The repertoire of interactive cell behaviors and the quantity of cellular players involved call for a social cell biology that investigates these interactions. Research into this social cell biology is critical for understanding development of normal and tumoral tissues. Such complex social cell biology interactions can be parsed in Drosophila. Techniques in Drosophila for analysis of gene function and clonal behavior allow us to generate tumors and dissect their complex interactive biology with cellular resolution. Here, we review recent Drosophila research aimed at understanding tissue-level biology and social cell interactions in tumors, highlighting the principles these studies reveal.

Upstream paths for Hippo signaling in Drosophila organ development.

PubMed

Choi, Kwang-Wook

2018-03-01

Organ growth is fundamental to animal development. One of major mechanisms for growth control is mediated by the conserved Hippo signaling pathway initially identified in Drosophila. The core of this pathway in Drosophila consists of a cascade of protein kinases Hippo and Warts that negatively regulate transcriptional coactivator Yorkie (Yki). Activation of Yki promotes cell survival and proliferation to induce organ growth. A key issue in Hippo signaling is to understand how core kinase cascade is activated. Activation of Hippo kinase cascade is regulated in the upstream by at least two transmembrane proteins Crumbs and Fat that act in parallel. These membrane proteins interact with additional factors such as FERM-domain proteins Expanded and Merlin to modulate subcellular localization and function of the Hippo kinase cascade. Hippo signaling is also influenced by cytoskeletal networks and cell tension in epithelia of developing organs. These upstream events in the regulation of Hippo signaling are only partially understood. This review focuses on our current understanding of some upstream processes involved in Hippo signaling in developing Drosophila organs. [BMB Reports 2018; 51(3): 134-142].

Drosophila Melanogaster as an Experimental Organism.

ERIC Educational Resources Information Center

Rubin, Gerald M.

1988-01-01

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

Imaging cell competition in Drosophila imaginal discs.

PubMed

Ohsawa, Shizue; Sugimura, Kaoru; Takino, Kyoko; Igaki, Tatsushi

2012-01-01

Cell competition is a process in which cells with higher fitness ("winners") survive and proliferate at the expense of less fit neighbors ("losers"). It has been suggested that cell competition is involved in a variety of biological processes such as organ size control, tissue homeostasis, cancer progression, and the maintenance of stem cell population. By advent of a genetic mosaic technique, which enables to generate fluorescently marked somatic clones in Drosophila imaginal discs, recent studies have presented some aspects of molecular mechanisms underlying cell competition. Now, with a live-imaging technique using ex vivo-cultured imaginal discs, we can dissect the spatiotemporal nature of competitive cell behaviors within multicellular communities. Here, we describe procedures and tips for live imaging of cell competition in Drosophila imaginal discs. Copyright © 2012 Elsevier Inc. All rights reserved.

A Test for Gene Flow among Sympatric and Allopatric Hawaiian Picture-Winged Drosophila.

PubMed

Kang, Lin; Garner, Harold R; Price, Donald K; Michalak, Pawel

2017-06-01

The Hawaiian Drosophila are one of the most species-rich endemic groups in Hawaii and a spectacular example of adaptive radiation. Drosophila silvestris and D. heteroneura are two closely related picture-winged Drosophila species that occur sympatrically on Hawaii Island and are known to hybridize in nature, yet exhibit highly divergent behavioral and morphological traits driven largely through sexual selection. Their closest-related allopatric species, D. planitibia from Maui, exhibits hybrid male sterility and reduced behavioral reproductive isolation when crossed experimentally with D. silvestris or D. heteroneura. A modified four-taxon test for gene flow was applied to recently obtained genomes of the three Hawaiian Drosophila species. The analysis indicates recent gene flow in sympatry, but also, although less extensive, between allopatric species. This study underscores the prevalence of gene flow, even in taxonomic groups considered classic examples of allopatric speciation on islands. The potential confounding effects of gene flow in phylogenetic and population genetics inference are discussed, as well as the implications for conservation.

Laser ablation of Drosophila embryonic motoneurons causes ectopic innervation of target muscle fibers

NASA Technical Reports Server (NTRS)

Chang, T. N.; Keshishian, H.

1996-01-01

We have tested the effects of neuromuscular denervation in Drosophila by laser-ablating the RP motoneurons in intact embryos before synaptogenesis. We examined the consequences of this ablation on local synaptic connectivity in both 1st and 3rd instar larvae. We find that the partial or complete loss of native innervation correlates with the appearance of alternate inputs from neighboring motor endings and axons. These collateral inputs are found at ectopic sites on the denervated target muscle fibers. The foreign motor endings are electrophysiologically functional and are observed on the denervated muscle fibers by the 1st instar larval stage. Our data are consistent with the existence of a local signal from the target environment, which is regulated by innervation and influences synaptic connectivity. Our results show that, despite the stereotypy of Drosophila neuromuscular connections, denervation can induce local changes in connectivity in wild-type Drosophila, suggesting that mechanisms of synaptic plasticity may also be involved in normal Drosophila neuromuscular development.

Faster-X Evolution of Gene Expression in Drosophila

PubMed Central

Meisel, Richard P.; Malone, John H.; Clark, Andrew G.

2012-01-01

DNA sequences on X chromosomes often have a faster rate of evolution when compared to similar loci on the autosomes, and well articulated models provide reasons why the X-linked mode of inheritance may be responsible for the faster evolution of X-linked genes. We analyzed microarray and RNA–seq data collected from females and males of six Drosophila species and found that the expression levels of X-linked genes also diverge faster than autosomal gene expression, similar to the “faster-X” effect often observed in DNA sequence evolution. Faster-X evolution of gene expression was recently described in mammals, but it was limited to the evolutionary lineages shortly following the creation of the therian X chromosome. In contrast, we detect a faster-X effect along both deep lineages and those on the tips of the Drosophila phylogeny. In Drosophila males, the dosage compensation complex (DCC) binds the X chromosome, creating a unique chromatin environment that promotes the hyper-expression of X-linked genes. We find that DCC binding, chromatin environment, and breadth of expression are all predictive of the rate of gene expression evolution. In addition, estimates of the intraspecific genetic polymorphism underlying gene expression variation suggest that X-linked expression levels are not under relaxed selective constraints. We therefore hypothesize that the faster-X evolution of gene expression is the result of the adaptive fixation of beneficial mutations at X-linked loci that change expression level in cis. This adaptive faster-X evolution of gene expression is limited to genes that are narrowly expressed in a single tissue, suggesting that relaxed pleiotropic constraints permit a faster response to selection. Finally, we present a conceptional framework to explain faster-X expression evolution, and we use this framework to examine differences in the faster-X effect between Drosophila and mammals. PMID:23071459

Bacterial Communities of Diverse Drosophila Species: Ecological Context of a Host–Microbe Model System

PubMed Central

Bhatnagar, Srijak; Eisen, Jonathan A.; Kopp, Artyom

2011-01-01

Drosophila melanogaster is emerging as an important model of non-pathogenic host–microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal–microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host–microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host–microbe interactions. Bacterial taxa used in experimental studies are rare or absent in

Citizen scientist lepidopterists exposed to potential carcinogens.

PubMed

Vainio, Petri J; Vahlberg, Tero; Liesivuori, Jyrki

2016-05-01

Lepidopterists use substantial volumes of solvents, such as chloroform, 1,1,2,2-tetrachloroethane and xylene, in their traps when collecting faunistic and phenological data. A majority of them are citizen scientists and thus in part not identified by occupational healthcare as being at risk due to solvent handling. We surveyed the extent of solvent use, the frequency and extent of potential exposure and the safety precautions taken in trapping and catch handling by Finnish lepidopterists. Chloroform and 1,1,2,2-tetrachloroethane were the most frequently used anaesthetics. Potential for exposure prevailed during trap maintenance and exploration and catch sorting. Adequate protection against vapours or spills was worn by 17% during trap exploration. Subjects completed a median of 100 trap explorations per season. Dermal or mucosal spills were recorded at a median rate of one spill per ten (chloroform) to 20 (1,1,2,2-tetrachloroethane and xylene) trap explorations. Median annual cumulative durations of 8 and 20 h of exposure to chloroform and 1,1,2,2-tetrachloroethane at levels above odour detection threshold were reported. Subjective adverse findings possibly related solvents had been noticed by 24 (9.8%) lepidopterists. All the events had been mild to moderate. No factor predicting unsafe procedures or adverse reactions was recorded despite thorough statistical testing. Copyright © 2016 Elsevier Ltd. All rights reserved.

cAMP signalling in mushroom bodies modulates temperature preference behaviour in Drosophila.

PubMed

Hong, Sung-Tae; Bang, Sunhoe; Hyun, Seogang; Kang, Jongkyun; Jeong, Kyunghwa; Paik, Donggi; Chung, Jongkyeong; Kim, Jaeseob

2008-08-07

Homoiotherms, for example mammals, regulate their body temperature with physiological responses such as a change of metabolic rate and sweating. In contrast, the body temperature of poikilotherms, for example Drosophila, is the result of heat exchange with the surrounding environment as a result of the large ratio of surface area to volume of their bodies. Accordingly, these animals must instinctively move to places with an environmental temperature as close as possible to their genetically determined desired temperature. The temperature that Drosophila instinctively prefers has a function equivalent to the 'set point' temperature in mammals. Although various temperature-gated TRP channels have been discovered, molecular and cellular components in Drosophila brain responsible for determining the desired temperature remain unknown. We identified these components by performing a large-scale genetic screen of temperature preference behaviour (TPB) in Drosophila. In parallel, we mapped areas of the Drosophila brain controlling TPB by targeted inactivation of neurons with tetanus toxin and a potassium channel (Kir2.1) driven with various brain-specific GAL4s. Here we show that mushroom bodies (MBs) and the cyclic AMP-cAMP-dependent protein kinase A (cAMP-PKA) pathway are essential for controlling TPB. Furthermore, targeted expression of cAMP-PKA pathway components in only the MB was sufficient to rescue abnormal TPB of the corresponding mutants. Preferred temperatures were affected by the level of cAMP and PKA activity in the MBs in various PKA pathway mutants.

Comparative genome sequencing of Drosophila pseudoobscura: Chromosomal, gene, and cis-element evolution

PubMed Central

Richards, Stephen; Liu, Yue; Bettencourt, Brian R.; Hradecky, Pavel; Letovsky, Stan; Nielsen, Rasmus; Thornton, Kevin; Hubisz, Melissa J.; Chen, Rui; Meisel, Richard P.; Couronne, Olivier; Hua, Sujun; Smith, Mark A.; Zhang, Peili; Liu, Jing; Bussemaker, Harmen J.; van Batenburg, Marinus F.; Howells, Sally L.; Scherer, Steven E.; Sodergren, Erica; Matthews, Beverly B.; Crosby, Madeline A.; Schroeder, Andrew J.; Ortiz-Barrientos, Daniel; Rives, Catharine M.; Metzker, Michael L.; Muzny, Donna M.; Scott, Graham; Steffen, David; Wheeler, David A.; Worley, Kim C.; Havlak, Paul; Durbin, K. James; Egan, Amy; Gill, Rachel; Hume, Jennifer; Morgan, Margaret B.; Miner, George; Hamilton, Cerissa; Huang, Yanmei; Waldron, Lenée; Verduzco, Daniel; Clerc-Blankenburg, Kerstin P.; Dubchak, Inna; Noor, Mohamed A.F.; Anderson, Wyatt; White, Kevin P.; Clark, Andrew G.; Schaeffer, Stephen W.; Gelbart, William; Weinstock, George M.; Gibbs, Richard A.

2005-01-01

We have sequenced the genome of a second Drosophila species, Drosophila pseudoobscura, and compared this to the genome sequence of Drosophila melanogaster, a primary model organism. Throughout evolution the vast majority of Drosophila genes have remained on the same chromosome arm, but within each arm gene order has been extensively reshuffled, leading to a minimum of 921 syntenic blocks shared between the species. A repetitive sequence is found in the D. pseudoobscura genome at many junctions between adjacent syntenic blocks. Analysis of this novel repetitive element family suggests that recombination between offset elements may have given rise to many paracentric inversions, thereby contributing to the shuffling of gene order in the D. pseudoobscura lineage. Based on sequence similarity and synteny, 10,516 putative orthologs have been identified as a core gene set conserved over 25–55 million years (Myr) since the pseudoobscura/melanogaster divergence. Genes expressed in the testes had higher amino acid sequence divergence than the genome-wide average, consistent with the rapid evolution of sex-specific proteins. Cis-regulatory sequences are more conserved than random and nearby sequences between the species—but the difference is slight, suggesting that the evolution of cis-regulatory elements is flexible. Overall, a pattern of repeat-mediated chromosomal rearrangement, and high coadaptation of both male genes and cis-regulatory sequences emerges as important themes of genome divergence between these species of Drosophila. PMID:15632085

Thermal performance of two indigenous pupal parasitoids attacking the invasive Drosophila suzukii (Diptera: Drosophilidae)

USDA-ARS?s Scientific Manuscript database

Pachycrepoideus vindemiae (Rondani) and Trichopria drosophilae (Perkins) are among a few indigenous parasitoids attacking the invasive Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) in North America. Both parasitoid species occur in California, whereas only P. vindemiae has been reported fr...

A novel mode of induction of the humoral innate immune response in Drosophila larvae

PubMed Central

Kenmoku, Hiroyuki

2017-01-01

ABSTRACT Drosophila adults have been utilized as a genetically tractable model organism to decipher the molecular mechanisms of humoral innate immune responses. In an effort to promote the utility of Drosophila larvae as an additional model system, in this study, we describe a novel aspect of an induction mechanism for innate immunity in these larvae. By using a fine tungsten needle created for manipulating semi-conductor devices, larvae were subjected to septic injury. However, although Toll pathway mutants were susceptible to infection with Gram-positive bacteria as had been shown for Drosophila adults, microbe clearance was not affected in the mutants. In addition, Drosophila larvae were found to be sensitive to mechanical stimuli with respect to the activation of a sterile humoral response. In particular, pinching with forceps to a degree that might cause minor damage to larval tissues could induce the expression of the antifungal peptide gene Drosomycin; notably, this induction was partially independent of the Toll and immune deficiency pathways. We therefore propose that Drosophila larvae might serve as a useful model to analyze the infectious and non-infectious inflammation that underlies various inflammatory diseases such as ischemia, atherosclerosis and cancer. PMID:28250052

Dopamine Dynamics and Signaling in Drosophila: An Overview of Genes, Drugs and Behavioral Paradigms

PubMed Central

Yamamoto, Shinya; Seto, Elaine S.

2014-01-01

Changes in dopamine (DA) signaling have been implicated in a number of human neurologic and psychiatric disorders. Similarly, defects in DA signaling in the fruit fly, Drosophila melanogaster, have also been associated with several behavioral defects. As most genes involved in DA synthesis, transport, secretion, and signaling are conserved between species, Drosophila is a powerful genetic model organism to study the regulation of DA signaling in vivo. In this review, we will provide an overview of the genes and drugs that regulate DA biology in Drosophila. Furthermore, we will discuss the behavioral paradigms that are regulated by DA signaling in flies. By analyzing the genes and neuronal circuits that govern such behaviors using sophisticated genetic, pharmacologic, electrophysiologic, and imaging approaches in Drosophila, we will likely gain a better understanding about how this neuromodulator regulates motor tasks and cognition in humans. PMID:24770636

Shared neurocircuitry underlying feeding and drugs of abuse in Drosophila.

PubMed

Landayan, Dan; Wolf, Fred W

2015-12-01

The neural circuitry and molecules that control the rewarding properties of food and drugs of abuse appear to partially overlap in the mammalian brain. This has raised questions about the extent of the overlap and the precise role of specific circuit elements in reward and in other behaviors associated with feeding regulation and drug responses. The much simpler brain of invertebrates including the fruit fly Drosophila, offers an opportunity to make high-resolution maps of the circuits and molecules that govern behavior. Recent progress in Drosophila has revealed not only some common substrates for the actions of drugs of abuse and for the regulation of feeding, but also a remarkable level of conservation with vertebrates for key neuromodulatory transmitters. We speculate that Drosophila may serve as a model for distinguishing the neural mechanisms underlying normal and pathological motivational states that will be applicable to mammals. Copyright © 2016 Chang Gung University. Published by Elsevier B.V. All rights reserved.

Altered Cytochrome c Display Precedes Apoptotic Cell Death in Drosophila

PubMed Central

Varkey, Johnson; Chen, Po; Jemmerson, Ronald; Abrams, John M.

1999-01-01

Drosophila affords a genetically well-defined system to study apoptosis in vivo. It offers a powerful extension to in vitro models that have implicated a requirement for cytochrome c in caspase activation and apoptosis. We found that an overt alteration in cytochrome c anticipates programmed cell death (PCD) in Drosophila tissues, occurring at a time that considerably precedes other known indicators of apoptosis. The altered configuration is manifested by display of an otherwise hidden epitope and occurs without release of the protein into the cytosol. Conditional expression of the Drosophila death activators, reaper or grim, provoked apoptogenic cytochrome c display and, surprisingly, caspase activity was necessary and sufficient to induce this alteration. In cell-free studies, cytosolic caspase activation was triggered by mitochondria from apoptotic cells but identical preparations from healthy cells were inactive. Our observations provide compelling validation of an early role for altered cytochrome c in PCD and suggest propagation of apoptotic physiology through reciprocal, feed-forward amplification involving cytochrome c and caspases. PMID:10037791

Drosophila melanogaster as a model system of aluminum toxicity and aging.

PubMed

Kijak, Ewelina; Rosato, Ezio; Knapczyk, Katarzyna; Pyza, Elżbieta

2014-04-01

The aim of this study was to investigate the toxic effects of aluminum (Al) on the model organism-Drosophila melanogaster. The study is especially concerned with the effects of aluminum on the fruit fly's development, life span, and circadian rhythm in rest and activity. Flies were exposed to aluminum in concentrations from 40 to 280 mg/kg in rearing media or the flies were raised on control medium. Moreover, the life span of insects exposed to aluminum containing 40, 120, or 240 mg/kg of Al in the medium, only during their larval development, during the whole life cycle and only in their adult life was tested. To check if aluminum and aging cause changes in D. melanogaster behavior, the locomotor activity of flies at different ages was recorded. Results showed that aluminum is toxic in concentrations above 160 mg/kg in the rearing medium. Depending on Al concentration and time of exposure, the life span of the flies was shortened. At intermediate concentrations (120 mg/kg), however, Al had a stimulating effect on males increasing their life span and level of locomotor activity. At higher concentration the aluminum exposure increased or decreased the level of locomotor activity of D. melanogaster depending on age of flies. In addition, in the oldest insects reared on aluminum supplemented media and in mid-aged flies reared on the highest concentration of Al the daily rhythm of activity was disrupted. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Methods to assess Drosophila heart development, function and aging

PubMed Central

Ocorr, Karen; Vogler, Georg; Bodmer, Rolf

2014-01-01

In recent years the Drosophila heart has become an established model of many different aspects of human cardiac disease. This model has allowed identification of disease-causing mechanisms underlying congenital heart disease and cardiomyopathies and has permitted the study underlying genetic, metabolic and age-related contributions to heart function. In this review we discuss methods currently employed in the analysis of the Drosophila heart structure and function, such as optical methods to infer heart function and performance, electrophysiological and mechanical approaches to characterize cardiac tissue properties, and conclude with histological techniques used in the study of heart development and adult structure. PMID:24727147

Uncoupling neurogenic gene networks in the Drosophila embryo.

PubMed

Rogers, William A; Goyal, Yogesh; Yamaya, Kei; Shvartsman, Stanislav Y; Levine, Michael S

2017-04-01

The EGF signaling pathway specifies neuronal identities in the Drosophila embryo by regulating developmental patterning genes such as intermediate neuroblasts defective ( ind ). EGFR is activated in the ventral midline and neurogenic ectoderm by the Spitz ligand, which is processed by the Rhomboid protease. CRISPR/Cas9 was used to delete defined rhomboid enhancers mediating expression at each site of Spitz processing. Surprisingly, the neurogenic ectoderm, not the ventral midline, was found to be the dominant source of EGF patterning activity. We suggest that Drosophila is undergoing an evolutionary transition in central nervous system (CNS)-organizing activity from the ventral midline to the neurogenic ectoderm. © 2017 Rogers et al.; Published by Cold Spring Harbor Laboratory Press.

Open-Ended Laboratory Investigations with Drosophila.

ERIC Educational Resources Information Center

Mertens, Thomas R.

1983-01-01

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

Investigation of Seasonal and Latitudinal Effects on the Expression of Clock Genes in Drosophila

NASA Astrophysics Data System (ADS)

Hosseini, Seyede Sanaz; Nazarimehr, Fahimeh; Jafari, Sajad

The primary goal in this work is to develop a dynamical model capturing the influence of seasonal and latitudinal variations on the expression of Drosophila clock genes. To this end, we study a specific dynamical system with strange attractors that exhibit changes of Drosophila activity in a range of latitudes and across different seasons. Bifurcations of this system are analyzed to peruse the effect of season and latitude on the behavior of clock genes. Existing experimental data collected from the activity of Drosophila melanogaster corroborate the dynamical model.

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

PubMed

Huser, Annina; Eschment, Melanie; Güllü, Nazli; Collins, Katharina A N; Böpple, Kathrin; Pankevych, Lyubov; Rolsing, Emilia; Thum, Andreas S

2017-01-01

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.

Anatomy and behavioral function of serotonin receptors in Drosophila melanogaster larvae