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Sample records for fungus cunninghamella elegans

  1. Biotransformation of Malachite Green by the Fungus Cunninghamella elegans

    PubMed Central

    Cha, Chang-Jun; Doerge, Daniel R.; Cerniglia, Carl E.

    2001-01-01

    The filamentous fungus Cunninghamella elegans ATCC 36112 metabolized the triphenylmethane dye malachite green with a first-order rate constant of 0.029 μmol h−1 (mg of cells)−1. Malachite green was enzymatically reduced to leucomalachite green and also converted to N-demethylated and N-oxidized metabolites, including primary and secondary arylamines. Inhibition studies suggested that the cytochrome P450 system mediated both the reduction and the N-demethylation reactions. PMID:11526047

  2. Biotransformation of fluorene by the fungus Cunninghamella elegans

    SciTech Connect

    Pothuluri, J.V.; Freeman, J.P.; Evans, F.E.; Cerniglia, C.E. )

    1993-06-01

    Fluorene, a tricyclic aromatic hydrocarbon, is formed during the combustion of fossil fuels and is an important pollutant of aquatic ecosystems where it is highly toxic to fish and algae. Few studies on microbial biodegradation of fluorene have been reported. This investigation describes the metabolism of fluorene by the fungus Cunninghamella elegans ATCC 36112 and the identification of major metabolites. 26 refs., 2 figs., 1 tab.

  3. Quinoline biodegradation by filamentous fungus Cunninghamella elegans and adaptive modifications of the fungal membrane composition.

    PubMed

    Felczak, Aleksandra; Bernat, Przemysław; Różalska, Sylwia; Lisowska, Katarzyna

    2016-05-01

    Quinoline, which belongs to N-heterocyclic compounds, occurs naturally in the environment and is used in numerous industrial processes. The structures of various chemicals, such as dyes and medicines, are based on this compound. Due to that fact, quinoline and its derivatives are widely distributed in environment and can exert toxic effects on organisms from different trophic levels. The ability of the filamentous fungus Cunninghamella elegans IM 1785/21Gp to degrade quinoline and modulate the membrane composition in response to the pollutant was studied. C. elegans IM 1785/21Gp removes quinoline with high efficiency and transforms the pollutant into two novel hydroxylated derivatives, 2-hydroxyquinoline and 3-hydroxyquinoline. Moreover, due to the disruption in the membrane stability by quinoline, C. elegans IM 1785/21Gp modulates the fatty acid composition and phospholipid profile. PMID:26810790

  4. Stereoselective metabolism of anthracene and phenanthrene by the fungus Cunninghamella elegans

    SciTech Connect

    Cerniglia, C.E.; Yang, S.K.

    1984-01-01

    The fungus Cunninghamella elegans oxidized anthracene and phenanthrene to form predominately transdihydrodiols. The metabolites were isolated by reversed-phase high-pressure liquid chromatography for structural and conformational analyses. Comparison of the circular dichroism spectrum of the fungal trans-1,2-dihydroxy-1,2-dihydroanthracene to that formed by rat liver microsomes indicated that the major enantiomer of the trans-1,2-dihydroxy-1,2-dihydroanthracene formed by C. elegans had an S,S absolute stereochemistry, which is opposite to the predominately 1R,2R dihydrodiol formed by rat liver microsomes. C. elegans oxidized phenanthrene primarily in the 1,2-positions to form trans-1,2-dihydroxy-1,2-dihydrophenanthrene. In addition, a minor amount of trans-3,4-dihydroxy-3,4-dihydrophenanthrene was detected. Metabolism at the K-region (9,10-positions) of phenanthrene was not detected. Comparison of the circular dichroism spectra of the phenanthrene trans-1,2- and trans-3,4-dihydrodiols formed by C. elegans to those formed by mammalian enzymes indicated that each of the dihydrodiols formed by C. elegans had an S,S absolute configuration. The results indicate that there are differences in both the regio- and stereoselective metabolism of anthracene and phenanthrene between the fungus C. elegans and rat liver microsomes. 26 references.

  5. Stereoselective metabolism of anthracene and phenanthrene by the fungus Cunninghamella elegans.

    PubMed Central

    Cerniglia, C E; Yang, S K

    1984-01-01

    The fungus Cunninghamella elegans oxidized anthracene and phenanthrene to form predominately trans-dihydrodiols. The metabolites were isolated by reversed-phase high-pressure liquid chromatography for structural and conformational analyses. Comparison of the circular dichroism spectrum of the fungal trans-1,2-dihydroxy-1,2-dihydroanthracene to that formed by rat liver microsomes indicated that the major enantiomer of the trans-1,2-dihydroxy-1,2-dihydroanthracene formed by C. elegans had an S,S absolute stereochemistry, which is opposite to the predominately 1R,2R dihydrodiol formed by rat liver microsomes. C. elegans oxidized phenanthrene primarily in the 1,2-positions to form trans-1,2-dihydroxy-1,2-dihydrophenanthrene. In addition, a minor amount of trans-3,4-dihydroxy-3,4-dihydrophenanthrene was detected. Metabolism at the K-region (9,10-positions) of phenanthrene was not detected. Comparison of the circular dichroism spectra of the phenanthrene trans-1,2- and trans-3,4-dihydrodiols formed by C. elegans to those formed by mammalian enzymes indicated that each of the dihydrodiols formed by C. elegans had an S,S absolute configuration. The results indicate that there are differences in both the regio- and stereoselective metabolism of anthracene and phenanthrene between the fungus C. elegans and rat liver microsomes. PMID:6696409

  6. The fungus Cunninghamella elegans can produce human and equine metabolites of selective androgen receptor modulators (SARMs).

    PubMed

    Rydevik, Axel; Thevis, Mario; Krug, Oliver; Bondesson, Ulf; Hedeland, Mikael

    2013-05-01

    1. Selective androgen receptor modulators (SARMs) are a group of substances that have potential to be used as doping agents in sports. Being a relatively new group not available on the open market means that no reference materials are commercially available for the main metabolites. In the presented study, the in vitro metabolism of SARMs by the fungus Cunninghamella elegans has been investigated with the purpose of finding out if it can produce relevant human and equine metabolites. 2. Three different SARMs, S1, S4 and S24, were incubated for 5 days with C. elegans. The samples were analysed both with and without sample pretreatment using ultra performance liquid chromatography coupled to high resolution mass spectrometry. 3. All the important phase I and some phase II metabolites from human and horse were formed by the fungus. They were formed through reactions such as hydroxylation, deacetylation, O-dephenylation, nitro-reduction, acetylation and sulfonation. 4. The study showed that the fungus produced relevant metabolites of the SARMs and thus can be used to mimic mammalian metabolism. Furthermore, it has the potential to be used for future production of reference material. PMID:23153056

  7. Biotransformation of fluorobiphenyl by Cunninghamella elegans.

    PubMed

    Amadio, Jessica; Murphy, Cormac D

    2010-03-01

    The fungus Cunninghamella elegans is a useful model of human catabolism of xenobiotics. In this paper, the biotransformation of fluorinated biphenyls by C. elegans was investigated by analysis of the culture supernatants with a variety of analytical techniques. 4-Fluorobiphenyl was principally transformed to 4-fluoro-4'-hydroxybiphenyl, but other mono- and dihydroxylated compounds were detected in organic extracts by gas chromatography-mass spectrometry. Additionally, fluorinated water-soluble products were detected by (19)F NMR and were identified as sulphate and beta-glucuronide conjugates. Other fluorobiphenyls (2-fluoro-, 4,4'-difluoro- and 2,3,4,5,6-pentafluoro-biphenyl) were catabolised by C. elegans, yielding mono- and dihydroxylated products, but phase II metabolites were detected from 4,4'-difluorobiphenyl only. PMID:19956946

  8. Fungal transformation of fluoranthene. [Cunninghamella elegans

    SciTech Connect

    Pothuluri, J.V.; Freeman, J.P.; Evans, F.E.; Cerniglia, C.E. )

    1990-10-01

    The fungus Cunninghamella elegans ATCC 36112 metabolized approximately 80% of the 3-{sup 14}C-labeled fluoranthene (FA) added within 72 h of incubation. C. elegans metabolized FA to trans-2,3-dihydroxy-2,3-dihydrofluoranthene (trans-2,3-dihydrodiol), 8- and 9-hydroxyfluoranthene trans-2,3-dihydrodiol, 3-fluoranthene-{beta}-glucopyranoside, and 3-(8-hydroxyflouranthene)-{beta}-glucopyranoside. These metabolites were separated by thin-layer and reversed-phase high-performance liquid chromatography and identified by {sup 1}H nuclear magnetic resonance, UV, and mass spectral techniques. The major pathway involved hydroxylation to form a glucoside conjugate of 3-hydroxyfluoranthene and a glucoside conjugate of 3,8-dihydroxyfluoranthene which together accounted for 52% of the total ethyl acetate-soluble metabolites. C. elegans initially metabolized FA in the 2,3 position to form fluoranthene trans-2,3-dihydrodiol, which has previously been shown to be a biologically active compound in mammalian and bacterial genotoxicity tests. However, C. elegans formed predominantly glucoside conjugates of the phenolic derivatives of FA, which suggests that this fungus has the potential to detoxify FA.

  9. Biotransformation of patchoulol by Cunninghamella echinulata var. elegans.

    PubMed

    Xu, Fangfang; Liao, Kangsheng; Liu, Yuhong; Zhang, Zhenbiao; Guo, Dean; Su, Ziren; Liu, Bo

    2016-03-01

    Biocatalysis of patchoulol (PA) was performed by the fungus Cunninghamella echinulata var. elegans. Eight metabolites (1-8) including four new compounds were obtained, and their structures were elucidated as (5R,8S)-5,8 dihydroxypatchoulol (1), (5R*,9R*)-5,9 dihydroxypatchoulol (2), (6S*, 9S*)-6,9 dihydroxypatchoulol (3), and (4R*)-4 hydroxypatchoulol (4) by spectroscopic analysis. The absolute configuration of 1 was determined by single crystal X-ray diffraction. PMID:26778089

  10. Data on individual metabolites of synthetic cannabinoids JWH-018, JWH-073 and AM2201 by Cunninghamella elegans.

    PubMed

    Watanabe, Shimpei; Kuzhiumparambil, Unnikrishnan; Winiarski, Zophia; Fu, Shanlin

    2016-06-01

    Synthetic cannabinoids JWH-018, JWH-073 and AM2201 were metabolised by the fungus Cunninghamella elegans. In this article, data on individual metabolites of their retention times, mass accuracies, major product ions and structures indicated by product ions are presented. The data in this article is related to "Biotransformation of synthetic cannabinoids JWH-018, JWH-073 and AM2201 by Cunninghamella elegans" [1]. PMID:26977432

  11. Microbial transformation of 6-nitrobenzo(a)pyrene. [Cunninghamella elegans

    SciTech Connect

    Millner, G.C.; Fu, P.P.; Cerniglia, C.E.

    1986-01-01

    The fungal metabolism of the potent mutagenic and carcinogenic nitropolycyclic aromatic hydrocarbon (nitro-PAH) 6-nitrobenzo(a)pyrene (6-NO/sub 2/-BaP) was investigated. Cunninghamella elegans was incubated with 6-NO/sub 2/-BaP for periods ranging between 1 and 7 d, and the metabolites formed were separated by high-performance liquid chromatography and identified by their UV-visible absorption, mass, and /sup 1/H nuclear magnetic resonance spectra. The results of the study indicate that C. elegans metabolized 6-NO/sub 2/-BaP to glucoside and sulfate conjugates of 1- and 3-hydroxy 6-NO/sub 2/-BaP and suggests that glycosylation and sulfation reactions may represent detoxification pathways in the fungal metabolism of nitro-PAHs. Experiments using (G-/sup 3/H)-6-NO/sub 2/-BaP indicated that C. elegans metabolized 62% of 6-NO/sub 2/-BaP with 168 h. The data also indicated that the nitro group at the C-6 position of benzo(a)pyrene blocked metabolism at the regions peri to the nitro substituent (C-7, C-8 positions) and enhanced metabolism at the C-1 and C-3 positions. The ability of the fungus C. elegans to metabolize 6-NO/sub 2/-BaP to biologically inactive compounds may have practical applications in the detoxification of nitro-PAH-contaminated wastes.

  12. Data on individual metabolites of synthetic cannabinoids JWH-018, JWH-073 and AM2201 by Cunninghamella elegans

    PubMed Central

    Watanabe, Shimpei; Kuzhiumparambil, Unnikrishnan; Winiarski, Zophia; Fu, Shanlin

    2016-01-01

    Synthetic cannabinoids JWH-018, JWH-073 and AM2201 were metabolised by the fungus Cunninghamella elegans. In this article, data on individual metabolites of their retention times, mass accuracies, major product ions and structures indicated by product ions are presented. The data in this article is related to “Biotransformation of synthetic cannabinoids JWH-018, JWH-073 and AM2201 by Cunninghamella elegans” [1]. PMID:26977432

  13. Biotransformation of chlorpromazine and methdilazine by Cunninghamella elegans.

    PubMed Central

    Zhang, D; Freeman, J P; Sutherland, J B; Walker, A E; Yang, Y; Cerniglia, C E

    1996-01-01

    When tested as a microbial model for mammalian drug metabolism, the filamentous fungus Cunninghamella elegans metabolized chlorpromazine and methdilazine within 72 h. The metabolites were extracted by chloroform, separated by high-performance liquid chromatography, and characterized by proton nuclear magnetic resonance, mass, and UV spectroscopic analyses. The major metabolites of chlorpromazine were chlorpromazine sulfoxide (36%), N-desmethylchlorpromazine (11%), N-desmethyl-7-hydroxychlorpromazine (6%), 7-hydroxychlorpromazine sulfoxide (36%), N-hydroxychlorpromazine (11%), 7-hydroxychlorpromazine sulfoxide (5%), and chlorpromazine N-oxide (2%), all of which have been found in animal studies. The major metabolites of methdilazine were 3-hydroxymethdilazine (3%). (18)O(2) labeling experiments indicated that the oxygen atoms in methdilazine sulfoxide, methdilazine N-oxide, and 3-hydroxymethdilazine were all derived from molecular oxygen. The production of methdilazine sulfoxide and 3-hydroxymethdilazine was inhibited by the cytochrome P-450 inhibitors metyrapone and proadifen. An enzyme activity for the sulfoxidation of methdilazine was found in microsomal preparations of C. elegans. These experiments suggest that the sulfoxidation and hydroxylation of methdilazine and chlorpromazine by C. elegans are catalyzed by cytochrome P-450. PMID:8975609

  14. Fungal metabolism and detoxification of fluoranthene. [Cunninghamella elegans

    SciTech Connect

    Pothuluri, J.V.; Heflich, R.H.; Fu, P.P.; Cerniglia, C.E. )

    1992-03-01

    Five metabolites produced by Cunninghamella elegans from fluoranthene (FA) in biotransformation studies were investigated for mutagenic activity towards Salmonella typhimurium TA100 and TA104. Whereas FA displayed positive, dose-related mutagenic responses in both tester strains in the presence of a rat liver homogenate fraction, 3-FA-{beta}-glucopyranoside, 3-(8-hydroxy-FA)-{beta}-glucopyranoside, FA trans-2,3-dihydrodiol, and 8-hydroxy-FA trans-2,3-dihydrodiol were negative. 9-Hydroxy-FA trans-2,3-dihydrodiol showed a weak positive response in S. typhimurium TA100. Mutagenicity assays performed with samples extracted at 24-h intervals during incubation of C. elegans with FA for 120 h showed that mutagenic activity decreased with time. Comparative studies with rat liver microsomes indicated that FA trans-2,3-dihydrodiol, the previously identified proximal mutagenic metabolite of FA, was the major metabolite. The circular dichroism spectrum of the rat liver microsomal FA trans-2,3-dihydrodiol indicated that is was optically active. In contrast, the circular dichroism spectrum of the fungal FA trans-2,3-dihydrodiol showed no optical activity. These results indicate that C. elegans has the potential to detoxify FA and that the stereochemistry of its trans-2,3-dihydrodiol metabolite reduces its mutagenic potential.

  15. Transformation of 1- and 2-methylnaphthalene by Cunninghamella elegans

    SciTech Connect

    Cerniglia, C.E.; Lambert, K.J.; Miller, D.W.; Freeman, J.P.

    1984-01-01

    Cunninghamella elegans metabolized 1- and 2-methylnaphthalene primarily at the methyl group to form 1- and 2-hydroxymethylnaphthalene, respectively. Other compounds isolated and identified were 1- and 2-naphthoic acids, 5-hydroxy-1-naphthoic acid, 5-hydroxy-2-naphthoic acid, 6-hydroxy-2-naphthoic acid, and phenolic derivatives of 1- and 2-methylnaphthalene. The metabolites were isolated by thin-layer and reverse-phase high-presure liquid chromatography and characterized by the application of UV-visible absorption, /sup 1/H nuclear magnetic resonance, and mass spectral techniques. Experiments with (8-/sup 14/C)2-methylnaphthalene indicated that over a 72-h period, 9.8% of 2-methylnaphthalene was oxidized to metabolic products. The ratio of organic-soluble to water-soluble metabolites at 2 h was 92:8, and at 72 h it was 41:59. Enzymatic treatment of the 48-h aqueous phase with either ..beta..-glucuronidase or arylsufatase released 60% of the metabolites of 2-methylnaphthalene that were extractable with ethyl acetate. In both cases, the major conjugates released were 5-hydroxy-2-naphthoic acid and 6-hydroxy-2-naphthoic acid. The ratio of the water-soluble glucuronide conjugates to sulfate conjugates was 1:1. Incubation of C. elegans with 2-methylnaphthalene under an /sup 18/O/sub 2/ atmosphere and subsequent mass spectral analysis of 2-hydroxymethylnaphthalene indicated that hydroxylation of the methyl group is catalyzed by a monooxygenase. 23 references.

  16. Biotransformation of synthetic cannabinoids JWH-018, JWH-073 and AM2201 by Cunninghamella elegans.

    PubMed

    Watanabe, Shimpei; Kuzhiumparambil, Unnikrishnan; Winiarski, Zofia; Fu, Shanlin

    2016-04-01

    Being marketed as "legal" smoking blends or mixtures, synthetic cannabinoids are abused widely owing to its cannabis-like effect. Due to the rapid introduction of new generation analogues of synthetic cannabinoids to escape from legislative/judicial control, the investigation of the metabolic pathways of these substances is of particular importance for drug control, abstinence and forensic toxicology purposes. In this study, the in vitro metabolism of JWH-018, JWH-073 and AM2201 by the fungus Cunninghamella elagans has been investigated with the purpose of validating its potential as a complementary model for investigating synthetic cannabinoid metabolism. JWH-018, JWH-073 and AM2201 were incubated for 72h with C. elegans. Detection of metabolites was based on liquid chromatography-tandem mass spectrometry and high resolution mass spectrometry analysis. C. elegans was found capable of producing the majority of the phase I metabolites observed in earlier in vitro and in vivo mammalian studies as a result of monohydroxylation, dihydroxylation, carboxylation, dehydrogenation, ketone formation, dihydrodiol formation, dihydrodiol formation with N-dealkylation and combinations thereof. C. elegans can thus be a useful and economic model for studying synthetic cannabinoid metabolism. PMID:26907475

  17. Mass spectrometric characterization of glucuronides formed by a new concept, combining Cunninghamella elegans with TEMPO.

    PubMed

    Rydevik, Axel; Bondesson, Ulf; Thevis, Mario; Hedeland, Mikael

    2013-10-01

    A new concept for the production of drug glucuronides is presented and the products formed were characterized using ultra high performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). Glucuronic acid conjugates are important phase II metabolites of a wide range of drugs. There is a lack of commercially available glucuronides and classic synthetic methods are tedious and expensive. Thus, new methods of glucuronide synthesis are needed. Selective androgen receptor modulators (SARMs) of the aryl propionamide class were used as model compounds and were incubated with the fungus Cunninghamella elegans which was previously known to conjugate drugs with glucose. The resulting glucoside metabolites were then oxidized with tetramethylpiperidinyl-1-oxy (TEMPO). UPLC-HRMS analysis showed that the peaks corresponding to the glucosides had disappeared after the reaction and were replaced by peaks with m/z consistent with the corresponding glucuronic acid conjugates. The MS/MS spectra of the reaction products were investigated and the observed fragment ion pattern corroborated the suggested structural change. A comparison in terms of retention times and product ion spectra between the glucuronides formed by the new method and those produced by liver microsomes indicated that the conjugates from the two different sources were identical, thus demonstrating the human relevance of the presented technique. Furthermore, the glucuronides formed by the presented method were readily hydrolyzed by β-glucuronidase which further gave evidence as to the fact that they were of β configuration. The investigated method was easy to perform, required a low input of work and had a low cost. PMID:23867089

  18. Biodegradation of bisphenol A and its halogenated analogues by Cunninghamella elegans ATCC36112.

    PubMed

    Keum, Young Soo; Lee, Hye Ri; Park, Hee Won; Kim, Jeong-Han

    2010-11-01

    Bisphenol A and its halogenated analogues are commonly used industrial chemicals with strong toxicological effects over many organisms. In this study, metabolic fate of bisphenol A and its halogenated analogues were evaluated with Cunninghamella elegans ATCC36112. Bisphenol A and related analogues were rapidly transformed into several metabolites by C. elegans within 2-4 days. Detailed analysis of metabolites reveals that both phase I and II metabolism occurred in C. elegans. Cytochrome P450-dependent hydroxylation was observed in BPA. However, major reaction with bisphenol A and analogues with 1-2 halogen atoms were the formation of glucose-conjugate, not being inhibited by cytochrome P450 inhibitor. Overall metabolic rates decreased with increasing number of substitution at 2- and 6-position of BPA structures, which may be consequences of limited bioavailability or steric hindrance to conjugate-forming reaction. Information from the current study will provide detailed insights over the fungal metabolism of BPA and analogues. PMID:20455075

  19. Cadmium Tolerance and Removal from Cunninghamella elegans Related to the Polyphosphate Metabolism

    PubMed Central

    de Lima, Marcos A. B.; Franco, Luciana de O.; de Souza, Patrícia M.; do Nascimento, Aline E.; da Silva, Carlos A. A.; Maia, Rita de C. C.; Rolim, Hercília M. L.; Takaki, Galba M. C.

    2013-01-01

    The aim of the present work was to study the cadmium effects on growth, ultrastructure and polyphosphate metabolism, as well as to evaluate the metal removal and accumulation by Cunninghamella elegans (IFM 46109) growing in culture medium. The presence of cadmium reduced growth, and a longer lag phase was observed. However, the phosphate uptake from the culture medium increased 15% when compared to the control. Moreover, C. elegans removed 70%–81% of the cadmium added to the culture medium during its growth. The C. elegans mycelia showed a removal efficiency of 280 mg/g at a cadmium concentration of 22.10 mg/L, and the removal velocity of cadmium was 0.107 mg/h. Additionally, it was observed that cadmium induced vacuolization, the presence of electron dense deposits in vacuoles, cytoplasm and cell membranes, as well as the distinct behavior of polyphosphate fractions. The results obtained with C. elegans suggest that precipitation, vacuolization and polyphosphate fractions were associated to cadmium tolerance, and this species demonstrated a higher potential for bioremediation of heavy metals. PMID:23538844

  20. Microbial models of mammalian metabolism. Biotransformations of N-methylcarbazole using the fungus Cunninghamella echinulata.

    PubMed

    Yang, W; Davis, P J

    1992-01-01

    The fungal metabolism of N-methylcarbazole (NMC) was investigated during the development of microbial models of mammalian metabolism. NMC was metabolized by the fungus Cunninghamella echinulata (ATCC 9244) to generate four metabolites: carbazole, N-hydroxymethylcarbazole (NHMC), 3-hydroxycarbazole, and 3-hydroxy-NHMC. Carbazole and NHMC are two major metabolites previously identified in mammalian systems, while 3-hydroxycarbazole and 3-hydroxy-NHMC have not been previously reported as metabolites of NMC. Structural identification of the four metabolites was based upon spectral (UV, MS, and NMR) and chromatographic (TLC and HPLC) comparisons with synthetic standards. These studies demonstrate that C. echinulata catalyzes the two principal biotransformations observed in mammalian systems with NMC: aliphatic hydroxylation to yield the (relatively) stable carbinolamine NHMC (with slow decomposition to the N-dealkylated product, carbazole) and aromatic hydroxylation in the 3-position. PMID:1346994

  1. Enhanced Biotransformation of Fluoranthene by Intertidally Derived Cunninghamella elegans under Biofilm-Based and Niche-Mimicking Conditions

    PubMed Central

    Mitra, Sayani; Pramanik, Arnab; Banerjee, Srijoni; Haldar, Saubhik; Gachhui, Ratan

    2013-01-01

    The aims of the investigation were to ascertain if surface attachment of Cunninghamella elegans and niche intertidal conditions provided in a bioreactor influenced biotransformation of fluoranthene by C. elegans. A newly designed polymethylmethacrylate (PMMA) conico-cylindrical flask (CCF) holding eight equidistantly spaced rectangular strips mounted radially on a circular disc allowed comparison of fluoranthene biotransformation between CCFs with a hydrophobic surface (PMMA-CCF) and a hydrophilic glass surface (GS-CCF) and a 500-ml Erlenmeyer flask (EF). Fluoranthene biotransformation was higher by 22-fold, biofilm growth was higher by 3-fold, and cytochrome P450 gene expression was higher by 2.1-fold when C. elegans was cultivated with 2% inoculum as biofilm culture in PMMA-CCF compared to planktonic culture in EF. Biotransformation was enhanced by 7-fold with 10% inoculum. The temporal pattern of biofilm progression based on three-channel fluorescence detection by confocal laser scanning microscopy demonstrated well-developed, stable biofilm with greater colocalization of fluoranthene within extracellular polymeric substances and filaments of the biofilm grown on PMMA in contrast to a glass surface. A bioreactor with discs rotating at 2 revolutions per day affording 6-hourly emersion and immersion mimicked the niche intertidal habitat of C. elegans and supported biofilm formation and transformation of fluoranthene. The amount of transformed metabolite was 3.5-fold, biofilm growth was 3-fold, and cytochrome P450 gene expression was 1.9-fold higher in the process mimicking the intertidal conditions than in a submerged process without disc rotation. In the CCF and reactor, where biofilm formation was comparatively greater, higher concentration of exopolysaccharides allowed increased mobilization of fluoranthene within the biofilm with consequential higher gene expression leading to enhanced volumetric productivity. PMID:24038685

  2. Biotransformation of flurbiprofen by Cunninghamella species.

    PubMed

    Amadio, Jessica; Gordon, Katherine; Murphy, Cormac D

    2010-09-01

    The biotransformation of the fluorinated anti-inflammatory drug flurbiprofen was investigated in Cunninghamella spp. Mono- and dihydroxylated metabolites were detected using gas chromatography-mass spectrometry and fluorine-19 nuclear magnetic resonance spectroscopy, and the major metabolite 4'-hydroxyflurbiprofen was isolated by preparative high-pressure liquid chromatography (HPLC). Cunninghamella elegans DSM 1908 and C. blakesleeana DSM 1906 also produced a phase II (conjugated) metabolite, which was identified as the sulfated drug via deconjugation experiments. PMID:20656862

  3. Effect of corn steep liquor (CSL) and cassava wastewater (CW) on chitin and chitosan production by Cunninghamella elegans and their physicochemical characteristics and cytotoxicity.

    PubMed

    Berger, Lúcia Raquel Ramos; Stamford, Thayza Christina Montenegro; Stamford-Arnaud, Thatiana Montenegro; de Oliveira Franco, Luciana; do Nascimento, Aline Elesbão; Cavalcante, Horacinna M de M; Macedo, Rui Oliveira; de Campos-Takaki, Galba Maria

    2014-01-01

    Microbiological processes were used for chitin and chitosan production with Cunninghamella elegans UCP/WFCC 0542 grown in different concentrations of two agro-industrial wastes, corn steep liquor (CSL) and cassava wastewater (CW) established using a 2² full factorial design. The polysaccharides were extracted by alkali-acid treatment and characterized by infrared spectroscopy, viscosity, thermal analysis, elemental analysis, scanning electron microscopy and X-ray diffraction. The cytotoxicity of chitosan was evaluated for signs of vascular change on the chorioallantoic membrane of chicken eggs. The highest biomass (9.93 g/L) was obtained in trial 3 (5% CW, 8% CSL), the greatest chitin and chitosan yields were 89.39 mg/g and 57.82 mg/g, respectively, and both were obtained in trial 2 (10% CW, 4% CSL). Chitin and chitosan showed a degree of deacetylation of 40.98% and 88.24%, and a crystalline index of 35.80% and 23.82%, respectively, and chitosan showed low molecular weight (LMW 5.2 × 10³ Da). Chitin and chitosan can be considered non-irritating, due to the fact they do not promote vascular change. It was demonstrated that CSL and CW are effective renewable agroindustrial alternative substrates for the production of chitin and chitosan. PMID:24590203

  4. Harnessing indigenous plant seed oil for the production of bio-fuel by an oleaginous fungus, Cunninghamella blakesleeana- JSK2, isolated from tropical soil.

    PubMed

    Sukrutha, S K; Janakiraman, Savitha

    2014-01-01

    Cunninghamella blakesleeana- JSK2, a gamma-linolenic acid (GLA) producing tropical fungal isolate, was utilized as a tool to evaluate the influence of various plant seed oils on biomass, oleagenicity and bio-fuel production. The fungus accumulated 26 % total lipid of their dry biomass (2 g/l) and 13 % of GLA in its total fatty acid. Among the various plant seed oils tested as carbon sources for biotransformation studies, watermelon oil had an effect on biomass and total lipid increasing up to 9.24 g/l and 34 % respectively. Sunflower, pumpkin, and onion oil increased GLA content between 15-18 %. Interestingly, an indigenous biodiesel commodity, Pongamia pinnata oil showed tremendous effect on fatty acid profile in C. blakesleeana- JSK2, when used as a sole source of carbon. There was complete inhibition of GLA from 13 to 0 % and increase in oleic acid content, one of the key components of biodiesel to 70 % (from 20 % in control). Our results suggest the potential application of indigenous plant seed oils, particularly P. pinnata oil, for the production of economically valuable bio-fuel in oleaginous fungi in general, and C. blakesleeana- JSK2, in particular. PMID:24142351

  5. Eleganketal A, a highly oxygenated dibenzospiroketal from the marine-derived fungus Spicaria elegans KLA03.

    PubMed

    Luan, Yepeng; Wei, Hongjuan; Zhang, Zhenpei; Che, Qian; Liu, Yankai; Zhu, Tianjiao; Mándi, Attila; Kurtán, Tibor; Gu, Qianqun; Li, Dehai

    2014-07-25

    Eleganketal A (1), a naturally occurring aromatic polyketide possessing a rare highly oxygenated spiro[isobenzofuran-1,3'-isochroman] ring system, was isolated from the fungus Spicaria elegans KLA03 by culturing it in a modified mannitol-based medium. The structure of 1 including the absolute configuration was determined by combining spectroscopic analysis, synthesis of the racemic permethylated analogue, chiral-phase HPLC separation, and TDDFT-ECD analysis. PMID:24967847

  6. Bioactive Phenylalanine Derivatives and Cytochalasins from the Soft Coral-Derived Fungus, Aspergillus elegans

    PubMed Central

    Zheng, Cai-Juan; Shao, Chang-Lun; Wu, Lu-Yong; Chen, Min; Wang, Kai-Ling; Zhao, Dong-Lin; Sun, Xue-Ping; Chen, Guang-Ying; Wang, Chang-Yun

    2013-01-01

    One new phenylalanine derivative 4′-OMe-asperphenamate (1), along with one known phenylalanine derivative (2) and two new cytochalasins, aspochalasin A1 (3) and cytochalasin Z24 (4), as well as eight known cytochalasin analogues (5–12) were isolated from the fermentation broth of Aspergillus elegans ZJ-2008010, a fungus obtained from a soft coral Sarcophyton sp. collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods. The absolute configuration of 1 was determined by chemical synthesis and Marfey’s method. All isolated metabolites (1–12) were evaluated for their antifouling and antibacterial activities. Cytochalasins 5, 6, 8 and 9 showed strong antifouling activity against the larval settlement of the barnacle Balanus amphitrite, with the EC50 values ranging from 6.2 to 37 μM. This is the first report of antifouling activity for this class of metabolites. Additionally, 8 exhibited a broad spectrum of antibacterial activity, especially against four pathogenic bacteria Staphylococcus albus, S. aureus, Escherichia coli and Bacillus cereus. PMID:23752358

  7. Production of 3-nitropropionic acid by endophytic fungus Phomopsis longicolla isolated from Trichilia elegans A. JUSS ssp. elegans and evaluation of biological activity.

    PubMed

    Flores, Andressa Caroline; Pamphile, João Alencar; Sarragiotto, Maria Helena; Clemente, Edmar

    2013-05-01

    The compound 3-nitropropionic acid is a potent neurotoxic agent in animals and well-known as a potent inhibitor of Mycobacterium tuberculosis. In this research, we were able to extract this compound from the endophytic fungus, Phomopsis longicolla (FJ62759), isolated from Trichilia elegans A. JUSS ssp. elegans. The aim of this study was the isolation of secondary metabolites produced by P. longicolla, the chemical identification of these compounds and evaluation of their antimicrobial and insecticidal activity. To accomplish these goals, the fungus was cultured in BD broth for 25 days without agitation at 28 °C, and then the broth was separated from the mycelium. The supernatant was partitioned with dichloromethane (CH2Cl2), ethyl acetate (EtOAc), and butanol (BuOH) solvents resulting in 3 extracts. However, only the EtOAc extract was used for fractionation and chemical identification because it had the greatest mass. After common chromatographic procedures, the fractions were analyzed by nuclear magnetic resonance to elucidate the chemical components. This procedure resulted in the identification of 3-nitropropionic acid in the D fraction. Evaluation of the insecticidal and antimicrobial activity of this compound has been accomplished, and the results indicate good inhibition of the citrus pathogen Guignardia citricarpa and cocoa pathogen Moniliophthora perniciosa and slight inhibition of the human bacterial pathogens Micrococcus luteus, Salmonella typhi and slight inhibition of phytopathogenic bacteria Xanthomonas axonopodis pv. phaseoli. The evaluation of insecticide activity did not show mortality of the Diatraea saccharalis larvae by the metabolite 3-nitropropionic acid in the D fraction. The results suggest that P. longicolla is a bioactive metabolic producing endophytic fungus with biotechnological properties. PMID:23296917

  8. Onychomycosis due to Cunninghamella bertholletiae in an Immunocompetent Male from Central India

    PubMed Central

    Tadepalli, Karuna; Gupta, Pradeep Kumar; Asati, Dinesh P.; Biswas, Debasis

    2015-01-01

    Onychomycosis is a fungal infection of nails seen frequently in immune competent and immune compromised patients due to dermatophytes, Candida spp., Fusarium spp., Scopulariopsis brevicaulis, Penicillium spp., and Aspergillus spp. We report a case of onychomycosis in a young immunocompetent male who presented onycholysis of a solitary nail without inflammation. The etiological agent was diagnosed to be Cunninghamella bertholletiae, a fungus pertaining to the order Mucorales (subdivision Mucoromycotina) and known for some of the invasive lesions among immunocompromised patients. This case demonstrates the association of onychomycosis with Cunninghamella bertholletiae in an immune competent individual, not reported so far. PMID:26640729

  9. Phylogenetic diversity of endophytic leaf fungus isolates from the medicinal tree Trichilia elegans (Meliaceae).

    PubMed

    Rhoden, S A; Garcia, A; Rubin Filho, C J; Azevedo, J L; Pamphile, J A

    2012-01-01

    Various types of organisms, mainly fungi and bacteria, live within vegetal organs and tissues, without causing damage to the plant. These microorganisms, which are called endophytes, can be useful for biological control and plant growth promotion; bioactive compounds from these organisms may have medical and pharmaceutical applications. Trichilia elegans (Meliaceae) is a native tree that grows abundantly in several regions of Brazil. Preparations using the leaves, seeds, bark, and roots of many species of the Meliaceae family have been widely used in traditional medicine, and some members of the Trichilia genus are used in Brazilian popular medicine. We assessed the diversity of endophytic fungi from two wild specimens of T. elegans, collected from a forest remnant, by sequencing ITS1-5.8S-ITS2 of rDNA of the isolates. The fungi were isolated and purified; 97 endophytic fungi were found; they were separated into 17 morpho-groups. Of the 97 endophytic fungi, four genera (Phomopsis, Diaporthe, Dothideomycete, and Cordyceps) with 11 morpho-groups were identified. Phomopsis was the most frequent genus among the identified endophytes. Phylogenetic analysis showed two major clades: Sordariomycetes, which includes three genera, Phomopsis, Diaporthe, and Cordyceps, and the clade Dothideomycetes, which was represented by the order Pleosporales. PMID:22782630

  10. New Record of Mariannaea elegans var. elegans in Korea.

    PubMed

    Tang, Longqing; Hyun, Min Woo; Yun, Yeo Hong; Suh, Dong Yeon; Kim, Seong Hwan; Sung, Gi Ho

    2012-03-01

    A Mariannaea fungus was isolated during investigation of an elm tree infested with unidentified beetles. Based on morphological characteristics and molecular analysis of the internal transcribed spacer rDNA sequence, the fungus was identified as Mariannaea elegans var. elegans. Fungal growth was better on malt extract agar than on potato dextrose agar and oatmeal agar. Optimal temperature and pH for growth of the fungus were 30℃ and pH 7.0, respectively. The fungus was found to have the ability to produce extracellular enzymes such as amylase, β-glucosidase, cellulase, and protease. This is first report on M. elegans var. elegans in Korea. PMID:22783129

  11. Mechanism of hydroxylation of biphenyl by Cunninghamella echinulata.

    PubMed Central

    Smith, R V; Davis, P J; Clark, A M; Prasatik, S K

    1981-01-01

    The hydroxylation of [U-2H]biphenyl and [2,2',3,3',5,5',6,6'-2H]biphenyl by Cunninghamella echinulata A.T.C.C. 9244 has been studied. G.l.c.-mass-spectrometry analyses indicate the lack of an isotope effect during the hydroxylation of the perdeuterated substrate. Both g.l.c.-mass spectrometry and 1H n.m.r. were used to definitively demonstrate the presence of a 1,2-hydride-shift during the microbiological hydroxylation of [2,2',3,3',5,5',6,6'-2H]biphenyl. PMID:7306077

  12. Three new cytochalasins from the marine-derived fungus Spicaria elegans KLA03 by supplementing the cultures with L- and D-tryptophan.

    PubMed

    Wang, Fa-Zuo; Wei, Hong-Juan; Zhu, Tian-Jiao; Li, De-Hai; Lin, Zhen-Jian; Gu, Qian-Qun

    2011-05-01

    Three new cytochalasins Z(21) -Z(23) (1-3, resp.), together with five analogs, 4-8, were isolated from Spicaria elegans KLA03 by the OSMAC (one strain-many compounds) approach with adding L- and D-tryptophan during its cultivation. The structures of new cytochalasins were elucidated on the basis of comprehensive 1D- and 2D-NMR and HR-ESI-MS analyses. Cytochalasins Z(21) and Z(22) (1 and 2, resp.), and compound 5 showed cytotoxic activities against A-549 cell lines with IC(50) values of 8.2, 20.0, and 3.1 μM, respectively. PMID:21560237

  13. Biosurfactant-and-Bioemulsifier Produced by a Promising Cunninghamella echinulata Isolated from Caatinga Soil in the Northeast of Brazil

    PubMed Central

    Silva, Nadielly R. Andrade; Luna, Marcos A. C.; Santiago, André L. C. M. A.; Franco, Luciana O.; Silva, Grayce K. B.; de Souza, Patrícia M.; Okada, Kaoru; Albuquerque, Clarissa D. C.; da Silva, Carlos A. Alves; Campos-Takaki, Galba M.

    2014-01-01

    A Mucoralean fungus was isolated from Caatinga soil of Pernambuco, Northeast of Brazil, and was identified as Cunninghamella echinulata by morphological, physiological, and biochemical tests. This strain was evaluated for biosurfactant/bioemulsifier production using soybean oil waste (SOW) and corn steep liquor (CSL) as substrates, added to basic saline solution, by measuring surface tension and emulsifier index and activity. The best results showed the surface water tension was reduced from 72 to 36 mN/m, and an emulsification index (E24) of 80% was obtained using engine oil and burnt engine oil, respectively. A new molecule of biosurfactant showed an anionic charge and a polymeric chemical composition consisting of lipids (40.0% w/w), carbohydrates (35.2% w/w) and protein (20.3% w/w). In addition, the biosurfactant solution (1%) demonstrated its ability for an oil displacement area (ODA) of 37.36 cm2, which is quite similar to that for Triton X-100 (38.46 cm2). The stability of the reduction in the surface water tension as well as of the emulsifier index proved to be stable over a wide range of temperatures, in pH, and in salt concentration (4%–6% w/v). The biosurfactant showed an ability to reduce and increase the viscosity of hydrophobic substrates and their molecules, suggesting that it is a suitable candidate for mediated enhanced oil recovery. At the same time, these studies indicate that renewable, relatively inexpensive and easily available resources can be used for important biotechnological processes. PMID:25257520

  14. Microbial models of mammalian metabolism: involvement of cytochrome P450 in the N-demethylation of N-methylcarbazole by Cunninghamella echinulata.

    PubMed

    Yang, W; Jiang, T; Acosta, D; Davis, P J

    1993-09-01

    1. As previously reported (Yang and Davis 1992), N-methylcarbazole (NMC) is converted to N-hydroxymethylcarbazole (NHMC), and 3-hydroxy-N-hydroxymethylcarbazole (3-OH-NHMC), two relatively stable carbinolamine metabolites by the fungus Cunninghamella echinulata (ATCC 9244). Decomposition of these two carbinolamines yields the corresponding dealkylated metabolites, carbazole and 3-hydroxycarbazole. In the present study, the possible involvement of cytochrome P450 in the requisite N-alkyl hydroxylation reaction was examined. 2. Carbon monoxide, a classical P450 inhibitor, markedly inhibited the formation of NHMC, as did potassium cyanide. 1-Benzylimidazole, piperonyl butoxide and SKF-525A inhibited the formation of both NHMC and 3-OH-NHMC, while beta-naphthoflavone (5,6-benzoflavone) induced their formation. 3. The source of the oxygen atom in the metabolite NHMC was examined by GC/MS analysis of NHMC formed during incubation of NMC in H218O-enriched medium which resulted in no incorporation of labelled oxygen into the metabolite. 4. An intermolecular isotope effect was not observed for the formation of NHMC suggesting that C-H bond cleavage is not a rate limiting step in the formation of this metabolite under the conditions examined. 5. It was concluded that P450 enzymes may be involved in the N-demethylation of NMC catalyzed by this fungal model of mammalian metabolism, and provides further support for biochemical and mechanistic parallels between mammalian metabolism and microbial systems catalyzing phase-1 biotransformations. PMID:8291265

  15. Optimization of Aeration and Agitation Rate for Lipid and Gamma Linolenic Acid Production by Cunninghamella bainieri 2A1 in Submerged Fermentation Using Response Surface Methodology

    PubMed Central

    Saad, Normah; Abdeshahian, Peyman; Kalil, Mohd Sahaid; Wan Yusoff, Wan Mohtar

    2014-01-01

    The locally isolated filamentous fungus Cunninghamella bainieri 2A1 was cultivated in a 5 L bioreactor to produce lipid and gamma-linolenic acid (GLA). The optimization was carried out using response surface methodology based on a central composite design. A statistical model, second-order polynomial model, was adjusted to the experimental data to evaluate the effect of key operating variables, including aeration rate and agitation speed on lipid production. Process analysis showed that linear and quadratic effect of agitation intensity significantly influenced lipid production process (P < 0.01). The quadratic model also indicated that the interaction between aeration rate and agitation speed had a highly significant effect on lipid production (P < 0.01). Experimental results showed that a lipid content of 38.71% was produced in optimum conditions using an airflow rate and agitation speed of 0.32 vvm and 599 rpm, respectively. Similar results revealed that 0.058 (g/g) gamma-linolenic acid was produced in optimum conditions where 1.0 vvm aeration rate and 441.45 rpm agitation rate were used. The regression model confirmed that aeration and agitation were of prime importance for optimum production of lipid in the bioreactor. PMID:25610901

  16. Whole-Cell Mediated 11β-Hydroxylation on the Basic Limonoid Skeleton by Cunninghamella echinulata.

    PubMed

    Haldar, Saikat; Mulani, Fayaj A; Aarthy, Thiagarayaselvam; Thulasiram, Hirekodathakallu V

    2015-06-19

    Regio- and stereoselective 11β-hydroxylation was achieved on the basic limonoid skeleton through microbial transformation. Whole cells of Cunninghamella echinulata efficiently converted basic limonoids such as epoxyazadiradione, azadiradione, and gedunin to their 11β-hydroxy analogues as the sole metabolite. Fermentation conditions affecting the efficiency (96%) of biotransformation including substrate concentration, incubation period, pH, and temperature were optimized. The position and stereochemistry of hydroxyl functionality on the isolated metabolites were established through extensive spectroscopic and spectrometric studies (1D, 2D NMR, ESI-MS, and MS/MS). PMID:25985231

  17. Fungus Amongus

    ERIC Educational Resources Information Center

    Wakeley, Deidra

    2005-01-01

    This role-playing simulation is designed to help teach middle level students about the typical lifecycle of a fungus. In this interactive simulation, students assume the roles of fungi, spores, living and dead organisms, bacteria, and rain. As they move around a playing field collecting food and water chips, they discover how the organisms…

  18. Antimicrobial abietane diterpenoids from Plectranthus elegans.

    PubMed

    Dellar, J E; Cole, M D; Waterman, P G

    1996-02-01

    Two novel abietane diterpenoids have been isolated from the aerial material of Plectranthus elegans and identified as 11-hydroxy-12-oxo-7,9(11),13-abietatriene and 7 alpha,11-dihydroxy-12-methoxy-8,11,13-abietatriene. Their structures were determined through rigorous use of spectroscopic methods. Both inhibited spore germination of the fungus Cladosporium cucumerinum, in direct bioautography, at a dose of 1 microgram. The new diterpenes also inhibited the growth of Gram-positive bacteria, in the concentration range 10-40 micrograms ml-1 in broth dilution assay. No effect was observed against Gram-negative bacteria. The ecological implications of these findings are discussed. PMID:8835454

  19. Pulmonary zygomycosis with Cunninghamella bertholletiae in a killer whale (Orcinus orca).

    PubMed

    Abdo, W; Kakizoe, Y; Ryono, M; Dover, S R; Fukushi, H; Okuda, H; Kano, R; Shibahara, T; Okada, E; Sakai, H; Yanai, T

    2012-07-01

    An adult female killer whale (Orcinus orca) was transported to the Port of Nagoya public aquarium in June 2010. While the animal was being maintained in the aquarium there was a gradual decrease in body weight. On October 1st, 2010 the whale exhibited signs of gastrointestinal disease and died on January 14th, 2011. At necropsy examination the gastric compartments were filled with a large number of variably-sized rocks (total weight 81.4 kg) and there was marked ulceration in the third compartment. There were multifocal tubercle-like nodules within the lungs and on sectioning there were numerous abscesses and pulmonary cavities. Microscopically, there was severe suppurative pneumonia associated with fungal hyphae that were infrequently septate and often branched. Numerous bacterial colonies were also present. The hyphae demonstrated immunohistochemical cross-reactivity with Rhizomucor spp. and Cunninghamella bertholletiae was cultured. Bacteriological culture revealed the presence of Proteus mirabilis, Pseudomonas aeruginosa and Pseudomonas oryzihabitans. This case represents the first documentation of zygomycosis associated with C. bertholletiae in a marine mammal. PMID:22000035

  20. Production of gamma-linolenic acid by Cunninghamella echinulata cultivated on glucose and orange peel.

    PubMed

    Gema, H; Kavadia, A; Dimou, D; Tsagou, V; Komaitis, M; Aggelis, G

    2002-03-01

    A newly isolated strain of Cunninghamella echinulata grown on glucose produced significant quantities of biomass and cellular lipids in media with high C/N ratio. The oil yield from glucose consumed increased after nitrogen exhaustion in the growth medium, but gamma-linolenic acid (GLA) content in cellular oil systematically decreased during the lipid accumulation process. When lipid accumulation was completed, GLA concentration in the cellular lipids progressively increased. The highest GLA production (720 mg/l) was achieved in medium with a C/N ratio equal to 163. C. echinulata was also able to grow on orange peel. The C/N ratio in the orange peel decreased from 50 to 26 during solid-state fermentation. Maximum oxygen uptake was observed during assimilation of reducing sugars, whereas a polygalacturonase activity was detected after reducing sugars had been exhausted. The maximum GLA production was 1.2-1.5 mg/g of fermented peel, calculated on a dry weight basis. After enrichment of the pulp with inorganic nitrogen and glucose, an increase in the production of oil and GLA was observed. PMID:11935180

  1. C. elegans TRP channels

    PubMed Central

    Xiao, Rui; Xu, X.Z. Shawn

    2010-01-01

    TRP (transient receptor potential) channels represent a superfamily of cation channels found in all eukaryotes. The C. elegans genome encodes seventeen TRP channels covering all of the seven TRP subfamilies. Genetic analyses in C. elegans have implicated TRP channels in a wide spectrum of behavioral and physiological processes, ranging from sensory transduction (e.g. chemosensation, touch sensation, proprioception and osmosensation) to fertilization, drug dependence, organelle biogenesis, apoptosis, gene expression, and neurotransmitter/hormone release. Many C. elegans TRP channels share similar activation and regulatory mechanisms with their vertebrate counterparts. Studies in C. elegans have also revealed some previously unrecognized functions and regulatory mechanisms of TRP channels. C. elegans represents an excellent genetic model organism for the study of function and regulation of TRP channels in vivo. PMID:21290304

  2. Rice-Field Drowning-Associated Pneumonia in which Pseudomonas spp., Aspergillus fumigatus, and Cunninghamella sp. Are Isolated.

    PubMed

    Yamawaki, Satoshi; Nakashima, Kei; Suzuki, Fumi; Otsuki, Ayumu; Watanabe, Junko; Takai, Motohisa; Katsurada, Masahiro; Katsurada, Naoko; Ohkuni, Yoshihiro; Misawa, Masafumi; Kaneko, Norihiro; Otsuka, Yoshihito; Aoshima, Masahiro

    2016-01-01

    We herein report the case of an 84-year-old who developed pneumonia after drowning in a rice field. Besides Aspergillus fumigatus, many pathogens previously not reported in drowning-associated pneumonia (such as Pseudomonas fluorescens, Pseudomonas putida, Nocardia niigatensis, and Cunninghamella sp.) were isolated from his sputum. He received sulbactam/ampicillin, trimethoprim/sulfamethoxazole, voriconazole, levofloxacin and liposomal amphotericin B, but died due to respiratory failure. Because the patient had drowned in a contaminated stagnant rice field and had multiple lung cavities, zygomycosis was suspected. This report provides invaluable information for the consideration of zygomycosis after an individual drowning in a rice field, even in an immunocompetent patient. PMID:27041173

  3. Repeated Batch Fermentation Biotechnology for the Biosynthesis of Lipid and Gamma-Linolenic Acid by Cunninghamella bainieri 2A1

    PubMed Central

    Ganjali Dashti, Marjan; Abdeshahian, Peyman; Wan Yusoff, Wan Mohtar; Kalil, Mohd Sahaid; Abdul Hamid, Aidil

    2014-01-01

    The biosynthesis of biomedical products including lipid and gamma-linolenic acid (GLA) by Cunninghamella bainieri 2A1 was studied in repeated batch fermentation. Three key process variables, namely, glucose concentration, ammonium tartrate concentration, and harvesting time, were optimized using response surface methodology. Repeated batch fermentation was carried out by the cultivation of Cunninghamella bainieri 2A1 in nitrogen-limited medium with various nitrogen concentration (1–4 g/L) and glucose concentration (20–40 g/L) at three time intervals (12 h, 24 h, and 48 h). Experimental results showed that the highest lipid concentration of 6.2 g/L and the highest GLA concentration of 0.4 g/L were obtained in optimum conditions, where 20.2 g/L glucose, 2.12 g/L ammonium tartrate, and 48 h harvesting time were utilized. Statistical results showed that the interaction between glucose and ammonium tartrate concentration had highly significant effects on lipid and GLA biosynthesis (P < 0.01). Moreover, harvesting time had a significant interaction effect with glucose and ammonium tartrate concentration on lipid production (P < 0.05). PMID:25147817

  4. Demodex mite infestation of unknown significance in a patient with rhinocerebral mucormycosis due to Apophysomyces elegans species complex.

    PubMed

    Hallur, Vinaykumar; Singh, Gagandeep; Rudramurthy, Shivaprakash M; Kapoor, Rakesh; Chakrabarti, Arunaloke

    2013-06-01

    Demodex mites have been reported in the past as a cause of facial rash in immunosuppressed patients. Here, we report an interesting case of possible demodicosis associated with rhinocerebral mucormycosis. The association of mites with a fungus was detected on direct microscopic examination of the scrapings of a nasal ulcer. The mite and the fungus were identified as Demodex folliculorum and Apophysomyces elegans species complex, respectively. PMID:23475907

  5. Apophysomyces elegans: a novel cause of endogenous endophthalmitis in an immunocompetent individual.

    PubMed

    Dave, Vivek Pravin; Sharma, Savitri; Yogi, Rohit; Reddy, Swapna

    2014-12-01

    A 20-year-old male presented with sudden onset redness, pain, and decreased vision in his left eye. Best-corrected visual acuity in the left eye was noted to be perception of light positive with inaccurate projection. On clinical examination, he was diagnosed to have left eye endogenous endophthalmitis. Smear and culture of vitreous biopsy were positive for Apophysomyces elegans, a fungus known to cause extensive soft tissue infections systemically characteristically in immunocompetent individual. The patient was treated aggressively with topical, systemic, and intravitreal antifungals but had a poor visual and anatomical outcome. This is a first known report of endogenous endophthalmitis due to Apophysomyces elegans. PMID:25183462

  6. Transgenesis in C. elegans.

    PubMed

    Praitis, Vida; Maduro, Morris F

    2011-01-01

    The ability to manipulate the genome of organisms at will is perhaps the single most useful ability for the study of biological systems. Techniques for the generation of transgenics in the nematode Caenorhabditis elegans became available in the late 1980s. Since then, improvements to the original approach have been made to address specific limitations with transgene expression, expand on the repertoire of the types of biological information that transgenes can provide, and begin to develop methods to target transgenes to defined chromosomal locations. Many recent, detailed protocols have been published, and hence in this chapter, we will review various approaches to making C. elegans transgenics, discuss their applications, and consider their relative advantages and disadvantages. Comments will also be made on anticipated future developments and on the application of these methods to other nematodes. PMID:22118277

  7. Laser Microsurgery in Caenorhabditis elegans

    PubMed Central

    Fang-Yen, Christopher; Gabel, Christopher V.; Samuel, Aravinthan D. T.; Bargmann, Cornelia I.; Avery, Leon

    2013-01-01

    Laser killing of cell nuclei has long been a powerful means of examining the roles of individual cells in C. elegans. Advances in genetics, laser technology, and imaging have further expanded the capabilities and usefulness of laser surgery. Here, we review the implementation and application of currently used methods for target edoptical disruption in C. elegans. PMID:22226524

  8. Toxicity testing using Caenorhabditis elegans

    SciTech Connect

    Middendorf, P.J.; Dusenbery, D.B.; Williams, P.L.

    1995-12-31

    Caenorhabditis elegans is a small free-living nematode that is representative of what may be the most abundant animal group. It has been promoted as a possible model organism for toxicity testing in the laboratory and in field evaluations in part because more is known about its biology than any other animal, Toxicity tests using C. elegans have been developed with lethality, reproduction, and behavior as end points. The tests have also been developed to varying degrees using standard laboratory media, water, and soil. The results of the tests when exposing C. elegans to a variety of metals, inorganic, and organic compounds indicate it is typically at least as sensitive as other species currently used, such as Daphnia and earthworms, and is generally much easier to maintain in the laboratory. The advantages and disadvantages of C. elegans and the state of development of the tests will be discussed.

  9. Mitochondrial division in Caenorhabditis elegans.

    PubMed

    Gandre, Shilpa; van der Bliek, Alexander M

    2007-01-01

    The study of mitochondrial division proteins has largely focused on yeast and mammalian cells. We describe methods to use Caenorhabditis elegans as an alternative model for studying mitochondrial division, taking advantage of the many wonderful resources provided by the C. elegans community. Our methods are largely based on manipulation of gene expression using classic and molecular genetic techniques combined with fluorescence microscopy. Some biochemical methods are also included. As antibodies become available, these biochemical methods are likely to become more sophisticated. PMID:18314747

  10. Neuropeptide GPCRs in C. elegans

    PubMed Central

    Frooninckx, Lotte; Van Rompay, Liesbeth; Temmerman, Liesbet; Van Sinay, Elien; Beets, Isabel; Janssen, Tom; Husson, Steven J.; Schoofs, Liliane

    2012-01-01

    Like most organisms, the nematode Caenorhabditis elegans relies heavily on neuropeptidergic signaling. This tiny animal represents a suitable model system to study neuropeptidergic signaling networks with single cell resolution due to the availability of powerful molecular and genetic tools. The availability of the worm’s complete genome sequence allows researchers to browse through it, uncovering putative neuropeptides and their cognate G protein-coupled receptors (GPCRs). Many predictions have been made about the number of C. elegans neuropeptide GPCRs. In this review, we report the state of the art of both verified as well as predicted C. elegans neuropeptide GPCRs. The predicted neuropeptide GPCRs are incorporated into the receptor classification system based on their resemblance to orthologous GPCRs in insects and vertebrates. Appointing the natural ligand(s) to each predicted neuropeptide GPCR (receptor deorphanization) is a crucial step during characterization. The development of deorphanization strategies resulted in a significant increase in the knowledge of neuropeptidergic signaling in C. elegans. Complementary localization and functional studies demonstrate that neuropeptides and their GPCRs represent a rich potential source of behavioral variability in C. elegans. Here, we review all neuropeptidergic signaling pathways that so far have been functionally characterized in C. elegans. PMID:23267347

  11. Batch culture and repeated-batch culture of Cunninghamella bainieri 2A1 for lipid production as a comparative study

    PubMed Central

    Dashti, Marjan Ganjali; Abdeshahian, Peyman

    2015-01-01

    This research was performed based on a comparative study on fungal lipid production by a locally isolated strain Cunninghamella bainieri 2A1 in batch culture and repeated-batch culture using a nitrogen-limited medium. Lipid production in the batch culture was conducted to study the effect of different agitation rates on the simultaneous consumption of ammonium tartrate and glucose sources. Lipid production in the repeated-batch culture was studied by considering the effect of harvesting time and harvesting volume of the culture broth on the lipid accumulation. The batch cultivation was carried out in a 500 ml Erlenmeyer flask containing 200 ml of the fresh nitrogen-limited medium. Microbial culture was incubated at 30 °C under different agitation rates of 120, 180 and 250 rpm for 120 h. The repeated-batch culture was performed at three harvesting times of 12, 24 and 48 h using four harvesting cultures of 60%, 70%, 80% and 90%. Experimental results revealed that nitrogen source (ammonium tartrate) was fully utilized by C. bainieri 2A1 within 24 h in all agitation rates tested. It was also observed that a high amount of glucose in culture medium was consumed by C. bainieri 2A1 at 250 rpm agitation speed during the batch fermentation. Similar results showed that the highest lipid concentration of 2.96 g/L was obtained at an agitation rate of 250 rpm at 120 h cultivation time with the maximum lipid productivity of 7.0 × 10−2 mg/ml/h. On the other hand, experimental results showed that the highest lipid concentration produced in the repeated-batch culture was 3.30 g/L at the first cycle of 48 h harvesting time using 70% harvesting volume, while 0.23 g/L gamma-linolenic acid (GLA) was produced at the last cycle of 48 h harvesting time using 80% harvesting volume. PMID:26980997

  12. Batch culture and repeated-batch culture of Cunninghamella bainieri 2A1 for lipid production as a comparative study.

    PubMed

    Dashti, Marjan Ganjali; Abdeshahian, Peyman

    2016-03-01

    This research was performed based on a comparative study on fungal lipid production by a locally isolated strain Cunninghamella bainieri 2A1 in batch culture and repeated-batch culture using a nitrogen-limited medium. Lipid production in the batch culture was conducted to study the effect of different agitation rates on the simultaneous consumption of ammonium tartrate and glucose sources. Lipid production in the repeated-batch culture was studied by considering the effect of harvesting time and harvesting volume of the culture broth on the lipid accumulation. The batch cultivation was carried out in a 500 ml Erlenmeyer flask containing 200 ml of the fresh nitrogen-limited medium. Microbial culture was incubated at 30 °C under different agitation rates of 120, 180 and 250 rpm for 120 h. The repeated-batch culture was performed at three harvesting times of 12, 24 and 48 h using four harvesting cultures of 60%, 70%, 80% and 90%. Experimental results revealed that nitrogen source (ammonium tartrate) was fully utilized by C. bainieri 2A1 within 24 h in all agitation rates tested. It was also observed that a high amount of glucose in culture medium was consumed by C. bainieri 2A1 at 250 rpm agitation speed during the batch fermentation. Similar results showed that the highest lipid concentration of 2.96 g/L was obtained at an agitation rate of 250 rpm at 120 h cultivation time with the maximum lipid productivity of 7.0 × 10(-2) mg/ml/h. On the other hand, experimental results showed that the highest lipid concentration produced in the repeated-batch culture was 3.30 g/L at the first cycle of 48 h harvesting time using 70% harvesting volume, while 0.23 g/L gamma-linolenic acid (GLA) was produced at the last cycle of 48 h harvesting time using 80% harvesting volume. PMID:26980997

  13. Intermediate Filaments in Caenorhabditis elegans.

    PubMed

    Zuela, Noam; Gruenbaum, Yosef

    2016-01-01

    More than 70 different genes in humans and 12 different genes in Caenorhabditis elegans encode the superfamily of intermediate filament (IF) proteins. In C. elegans, similar to humans, these proteins are expressed in a cell- and tissue-specific manner, can assemble into heteropolymers and into 5-10nm wide filaments that account for the principal structural elements at the nuclear periphery, nucleoplasm, and cytoplasm. At least 5 of the 11 cytoplasmic IFs, as well as the nuclear IF, lamin, are essential. In this chapter, we will include a short review of our current knowledge of both cytoplasmic and nuclear IFs in C. elegans and will describe techniques used for their analyses. PMID:26795488

  14. Fungal biotransformation of 6-nitrochrysene

    SciTech Connect

    Pothuluri, J.V.; Sutherland, J.B.; Freeman, J.P.; Cerniglia, C.E.

    1998-08-01

    The fungus Cunninghamella elegans was used to biotransform 6-nitrochrysene, a mutagen that is a widespread environmental contaminant. After 6 days, 74% of the {sup 3}H-labeled 6-nitrochrysene added had been metabolized to two isomeric sulfate conjugates. These conjugates were separated by high-performance liquid chromatography and identified by UV-visible, {sup 1}H nuclear magnetic resonance, and mass spectral techniques as 6-nitrochrysene 1-sulfate and 6-nitrochrysene 2-sulfate.

  15. C. elegans chemotaxis assay.

    PubMed

    Margie, Olivia; Palmer, Chris; Chin-Sang, Ian

    2013-01-01

    Many organisms use chemotaxis to seek out food sources, avoid noxious substances, and find mates. Caenorhabditis elegans has impressive chemotaxis behavior. The premise behind testing the response of the worms to an odorant is to place them in an area and observe the movement evoked in response to an odorant. Even with the many available assays, optimizing worm starting location relative to both the control and test areas, while minimizing the interaction of worms with each other, while maintaining a significant sample size remains a work in progress (1-10). The method described here aims to address these issues by modifying the assay developed by Bargmann et al.(1). A Petri dish is divided into four quadrants, two opposite quadrants marked "Test" and two are designated "Control". Anesthetic is placed in all test and control sites. The worms are placed in the center of the plate with a circle marked around the origin to ensure that non-motile worms will be ignored. Utilizing a four-quadrant system rather than one 2 or two 1 eliminates bias in the movement of the worms, as they are equidistant from test and control samples, regardless of which side of the origin they began. This circumvents the problem of worms being forced to travel through a cluster of other worms to respond to an odorant, which can delay worms or force them to take a more circuitous route, yielding an incorrect interpretation of their intended path. This method also shows practical advantages by having a larger sample size and allowing the researcher to run the assay unattended and score the worms once the allotted time has expired. PMID:23644543

  16. Proteomic analysis of Caenorhabditis elegans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteomic studies of the free-living nematode Caenorhabditis elegans have recently received great attention because this animal is a useful model platform for the in vivo study of various biological problems relevant to human disease. In general, proteomic analysis is performed in order to address a...

  17. Durotaxis in Nematode Caenorhabditis elegans.

    PubMed

    Parida, Lipika; Padmanabhan, Venkat

    2016-08-01

    Durotaxis is a process where cells are able to sense the stiffness of substrates and preferentially migrate toward stiffer regions. Here, we show that the 1-mm-long nematode, Caenorhabditis elegans are also able to detect the rigidity of underlying substrates and always migrate to regions of higher stiffness. Our results indicate that C. elegans are able to judiciously make a decision to stay on stiffer regions. We found that the, undulation frequency, and wavelength of worms, crawling on surfaces show nonmonotonic behavior with increasing stiffness. A number of control experiments were also conducted to verify whether C. elegans are really able to detect the rigidity of substrates or whether the migration to stiffer regions is due to other factors already reported in the literature. As it is known that bacteria and other single-celled organisms exhibit durotaxis toward stiffer surfaces, we conjecture that durotaxis in C. elegans may be one of the strategies developed to improve their chances of locating food. PMID:27508449

  18. Electrophysiological Methods for C. elegans Neurobiology

    PubMed Central

    Goodman, Miriam B.; Lindsay, Theodore H.; Lockery, Shawn R.; Richmond, Janet E.

    2014-01-01

    Patch-clamp electrophysiology is the technique of choice for the biophysical analysis of the function of nerve, muscle, and synapse in C. elegans nematodes. Considerable technical progress has been made in C. elegans electrophysiology in the decade since the initial publication of this technique. Today, most, if not all electrophysiological studies that can be done in larger animal preparations can also be done in C. elegans. This chapter has two main goals. The first is to present to a broad audience the many techniques available for patch-clamp analysis of neurons, muscles, and synapses in C. elegans. The second is to provide a methodological introduction to the techniques for patch-clamping C. elegans neurons and body-wall muscles in vivo, including emerging methods for optogenetic stimulation coupled with post-synaptic recording. We also present samples of the cell-intrinsic and post-synaptic ionic currents that can be measured in C. elegans nerve and muscle. PMID:22226532

  19. Yellow Pigment Aurovertins Mediate Interactions between the Pathogenic Fungus Pochonia chlamydosporia and Its Nematode Host.

    PubMed

    Wang, Yan-li; Li, Lin-fang; Li, Dong-xian; Wang, Baile; Zhang, Keqin; Niu, Xuemei

    2015-07-29

    Nematophagous fungi are globally distributed soil fungi and well-known natural predators of soil-dwelling nematodes. Pochonia chlamydosporia can be found in diverse nematode-suppressive soils as a parasite of nematode eggs and is one of the most studied potential biological control agents of nematodes. However, little is known about the functions of small molecules in the process of infection of nematodes by this parasitic fungus or about small-molecule-mediated interactions between the pathogenic fungus and its host. Our recent study demonstrated that a P. chlamydosporia strain isolated from root knots of tobacco infected by the root-knot nematode Meloidogyne incognita produced a class of yellow pigment metabolite aurovertins, which induced the death of the free-living nematode Panagrellus redivevus. Here we report that nematicidal P. chlamydosporia strains obtained from the nematode worms tended to yield a total yellow pigment aurovertin production exceeding the inhibitory concentration shown in nematicidal bioassays. Aurovertin D was abundant in the pigment metabolites of P. chlamydosporia strains. Aurovertin D showed strong toxicity toward the root-knot nematode M. incognita and exerted profound and detrimental effects on the viability of Caenorhabditis elegans even at a subinhibitory concentration. Evaluation of the nematode mutation in the β subunit of F1-ATPase, together with the application of RNA interference in screening each subunit of F1FO-ATPase in the nematode worms, demonstrated that the β subunit of F1-ATPase might not be the specific target for aurovertins in nematodes. The resistance of C. elegans daf-2(e1370) and the hypersensitivity of C. elegans daf-16(mu86) to aurovertin D indicated that DAF-16/FOXO transcription factor in nematodes was triggered in response to the aurovertin attack. These findings advance our understanding of the roles of aurovertin production in the interactions between nematodes and the pathogen fungus P. chlamydosporia

  20. Sensory Transduction in Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Brown, Austin L.; Ramot, Daniel; Goodman, Miriam B.

    The roundworm Caenorhabditis elegans has a well-defined and comparatively simple repertoire of sensory-guided behaviors, all of which rely on its ability to detect chemical, mechanical or thermal stimuli. In this chapter, we review what is known about the ion channels that mediate sensation in this remarkable model organism. Genetic screens for mutants defective in sensory-guided behaviors have identified genes encoding channel proteins, which are likely transducers of chemical, thermal, and mechanical stimuli. Such classical genetic approaches are now being coupled with molecular genetics and in vivo cellular physiology to elucidate how these channels are activated in specific sensory neurons. The ion channel superfamilies implicated in sensory transduction in C. elegans - CNG, TRP, and DEG/ENaC - are conserved across phyla and also appear to contribute to sensory transduction in other organisms, including vertebrates. What we learn about the role of these ion channels in C. elegans sensation is likely to illuminate analogous processes in other animals, including humans.

  1. Germline Transformation of Caenorhabditis elegans by Injection

    NASA Astrophysics Data System (ADS)

    Kadandale, Pavan; Chatterjee, Indrani; Singson, Andrew

    Microinjection is a commonly used technique for DNA transformation in Caenorhabditis elegans. It is a powerful tool that links genetic and molecular analysis to phenotypic analysis. In this chapter we shall provide an overview of microinjection for germline transformation in worms. Our discussion will emphasize C. elegans reproductive biology, applications and protocols for carrying out microinjection in order to successfully obtain transgenic worms.

  2. Cocaine modulates locomotion behavior in C. elegans.

    PubMed

    Ward, Alex; Walker, Vyvyca J; Feng, Zhaoyang; Xu, X Z Shawn

    2009-01-01

    Cocaine, a potent addictive substance, is an inhibitor of monoamine transporters, including DAT (dopamine transporter), SERT (serotonin transporter) and NET (norepinephrine transporter). Cocaine administration induces complex behavioral alterations in mammals, but the underlying mechanisms are not well understood. Here, we tested the effect of cocaine on C. elegans behavior. We show for the first time that acute cocaine treatment evokes changes in C. elegans locomotor activity. Interestingly, the neurotransmitter serotonin, rather than dopamine, is required for cocaine response in C. elegans. The C. elegans SERT MOD-5 is essential for the effect of cocaine, consistent with the role of cocaine in targeting monoamine transporters. We further show that the behavioral response to cocaine is primarily mediated by the ionotropic serotonin receptor MOD-1. Thus, cocaine modulates locomotion behavior in C. elegans primarily by impinging on its serotoninergic system. PMID:19536276

  3. Regulation of body fat in Caenorhabditis elegans.

    PubMed

    Srinivasan, Supriya

    2015-01-01

    Over the past decade, studies conducted in Caenorhabditis elegans have helped to uncover the ancient and complex origins of body fat regulation. This review highlights the powerful combination of genetics, pharmacology, and biochemistry used to study energy balance and the regulation of cellular fat metabolism in C. elegans. The complete wiring diagram of the C. elegans nervous system has been exploited to understand how the sensory nervous system regulates body fat and how food perception is coupled with the production of energy via fat metabolism. As a model organism, C. elegans also offers a unique opportunity to discover neuroendocrine factors that mediate direct communication between the nervous system and the metabolic tissues. The coming years are expected to reveal a wealth of information on the neuroendocrine control of body fat in C. elegans. PMID:25340962

  4. Metabolic inhibition of meloxicam by specific CYP2C9 inhibitors in Cunninghamella blakesleeana NCIM 687: in silico and in vitro studies.

    PubMed

    Prasad, G Shyam; Srisailam, K; Sashidhar, R B

    2016-01-01

    Specific inhibitors of Cytochrome P4502C9 enzyme (CYP2C9) viz. clopidogrel, fenofibrate fluvoxamine and sertraline at concentration of 50, 100, 150 and 200 µM were employed to investigate the nature of enzyme involved in bioconversion of meloxicam to its main metabolite 5-OH methyl meloxicam by Cunninghamella blakesleeana. Virtual screening for interaction of specific CYP2C9 inhibitors with human CYP2C9 enzyme was performed by molecular docking using Auto dock vina 4.2 version. The in silico studies were further substantiated by in vitro studies, which indicated fenofibrate to be a potent inhibitor of CYP2C9 enzyme followed by sertraline, clopidogrel and fluvoxamine, respectively. Two-stage fermentation protocol was followed to study metabolism of meloxicam and its inhibition by different CYP2C9 inhibitors. Meloxicam metabolites were identified using HPLC, LC-MS analysis and based on previous reports, as 5-OH methyl meloxicam (M1), 5-carboxy meloxicam (M2) and an unidentified metabolite (M3). All the inhibitors tested in the study showed a clear concentration dependent inhibition of meloxicam metabolism. The results suggest that the enzymes involved in metabolism of meloxicam in C. blakesleeana are akin to mammalian metabolism. Hence, C. blakesleeana can be used as a model organism in studying drug interactions and also in predicting mammalian drug metabolism. PMID:27026863

  5. Using C. elegans for aging research

    PubMed Central

    Tissenbaum, Heidi A.

    2015-01-01

    Over a century ago, the zoologist Emile Maupas first identified the nematode, Rhabditis elegans, in the soil in Algiers. Subsequent work and phylogenic studies renamed the species Caenorhabditis elegans or more commonly referred to as C. elegans; (Caeno meaning recent; rhabditis meaning rod; elegans meaning nice). However, it was not until 1963, when Sydney Brenner, already successful from his work on DNA, RNA, and the genetic code, suggested the future of biological research lay in model organisms. Brenner believed that biological research required a model system that could grow in vast quantities in the lab, were cheap to maintain and had a simple body plan, and he chose the nematode C. elegans to fulfill such a role. Since that time, C. elegans has emerged as one of the premiere model systems for aging research. This paper reviews some initial identification of mutants with altered lifespan with a focus on genetics and then discusses advantages and disadvantages for using C. elegans as a model system to understand human aging. This review focuses on molecular genetics aspects of this model organism. PMID:26136622

  6. Untwisting the Caenorhabditis elegans embryo

    PubMed Central

    Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

    2015-01-01

    The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis. DOI: http://dx.doi.org/10.7554/eLife.10070.001 PMID:26633880

  7. Gait synchronization in Caenorhabditis elegans

    PubMed Central

    Yuan, Jinzhou; Raizen, David M.; Bau, Haim H.

    2014-01-01

    Collective motion is observed in swarms of swimmers of various sizes, ranging from self-propelled nanoparticles to fish. The mechanisms that govern interactions among individuals are debated, and vary from one species to another. Although the interactions among relatively large animals, such as fish, are controlled by their nervous systems, the interactions among microorganisms, which lack nervous systems, are controlled through physical and chemical pathways. Little is known, however, regarding the mechanism of collective movements in microscopic organisms with nervous systems. To attempt to remedy this, we studied collective swimming behavior in the nematode Caenorhabditis elegans, a microorganism with a compact nervous system. We evaluated the contributions of hydrodynamic forces, contact forces, and mechanosensory input to the interactions among individuals. We devised an experiment to examine pair interactions as a function of the distance between the animals and observed that gait synchronization occurred only when the animals were in close proximity, independent of genes required for mechanosensation. Our measurements and simulations indicate that steric hindrance is the dominant factor responsible for motion synchronization in C. elegans, and that hydrodynamic interactions and genotype do not play a significant role. We infer that a similar mechanism may apply to other microscopic swimming organisms and self-propelled particles. PMID:24778261

  8. Untwisting the Caenorhabditis elegans embryo.

    PubMed

    Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

    2015-01-01

    The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis. PMID:26633880

  9. C. elegans outside the Petri dish.

    PubMed

    Frézal, Lise; Félix, Marie-Anne

    2015-01-01

    The roundworm Caenorhabditis elegans has risen to the status of a top model organism for biological research in the last fifty years. Among laboratory animals, this tiny nematode is one of the simplest and easiest organisms to handle. And its life outside the laboratory is beginning to be unveiled. Like other model organisms, C. elegans has a boom-and-bust lifestyle. It feasts on ephemeral bacterial blooms in decomposing fruits and stems. After resource depletion, its young larvae enter a migratory diapause stage, called the dauer. Organisms known to be associated with C. elegans include migration vectors (such as snails, slugs and isopods) and pathogens (such as microsporidia, fungi, bacteria and viruses). By deepening our understanding of the natural history of C. elegans, we establish a broader context and improved tools for studying its biology. PMID:25822066

  10. C. elegans outside the Petri dish

    PubMed Central

    Frézal, Lise; Félix, Marie-Anne

    2015-01-01

    The roundworm Caenorhabditis elegans has risen to the status of a top model organism for biological research in the last fifty years. Among laboratory animals, this tiny nematode is one of the simplest and easiest organisms to handle. And its life outside the laboratory is beginning to be unveiled. Like other model organisms, C. elegans has a boom-and-bust lifestyle. It feasts on ephemeral bacterial blooms in decomposing fruits and stems. After resource depletion, its young larvae enter a migratory diapause stage, called the dauer. Organisms known to be associated with C. elegans include migration vectors (such as snails, slugs and isopods) and pathogens (such as microsporidia, fungi, bacteria and viruses). By deepening our understanding of the natural history of C. elegans, we establish a broader context and improved tools for studying its biology. DOI: http://dx.doi.org/10.7554/eLife.05849.001 PMID:25822066

  11. Caenorhabditis elegans as an alternative animal species.

    PubMed

    Williams, P L; Anderson, G L; Johnstone, J L; Nunn, A D; Tweedle, M F; Wedeking, P

    2000-12-29

    Caenorhabditis elegans has proven useful in toxicity testing of known toxicants, but its potential for assessing the toxicity of new pharmaceuticals is relatively unexplored. In this study the procedures used in aquatic testing of toxicants were modified to permit testing of small amounts (<40 mg) of gadolinium-based magnetic resonance imaging (MRI) compounds. Five blinded compounds were tested. The toxicity of these compounds determined using C. elegans was compared to existing mammalian test system data (minimum lethal dose [MLD] values for mice). Four of five compounds tested had the same relative sensitivity with C. elegans as with the mouse test system. Testing with C. elegans is efficient and could markedly reduce the cost of screening potentially useful compounds. PMID:11132694

  12. Forward and reverse mutagenesis in C. elegans

    PubMed Central

    Kutscher, Lena M.; Shaham, Shai

    2014-01-01

    Mutagenesis drives natural selection. In the lab, mutations allow gene function to be deciphered. C. elegans is highly amendable to functional genetics because of its short generation time, ease of use, and wealth of available gene-alteration techniques. Here we provide an overview of historical and contemporary methods for mutagenesis in C. elegans, and discuss principles and strategies for forward (genome-wide mutagenesis) and reverse (target-selected and gene-specific mutagenesis) genetic studies in this animal. PMID:24449699

  13. Neurogenetics of vesicular transporters in C. elegans.

    PubMed

    Rand, J B; Duerr, J S; Frisby, D L

    2000-12-01

    The nematode Caenorhabditis elegans has a number of advantages for the analysis of synaptic molecules. These include a simple nervous system in which all cells are identified and synaptic connectivity is known and reproducible, a large collection of mutants and powerful methods of genetic analysis, simple methods for the generation and analysis of transgenic animals, and a number of relatively simple quantifiable behaviors. Studies in C. elegans have made major contributions to our understanding of vesicular transmitter transporters. Two of the four classes of vesicular transporters so far identified (VAChT and VGAT) were first described and cloned in C. elegans; in both cases, the genes were first identified and cloned by means of mutations causing a suggestive phenotype (1, 2). The phenotypes of eat-4 mutants and the cell biology of the EAT-4 protein were critical in the identification of this protein as the vesicular glutamate transporter (3, 4). In addition, the unusual gene structure associated with the cholinergic locus was first described in C. elegans (5). The biochemical properties of the nematode transporters are surprisingly similar to their vertebrate counterparts, and they can be assayed under similar conditions using the same types of mammalian cells (6, 7). In addition, mild and severe mutants (including knockouts) are available for each of the four C. elegans vesicular transporters, which has permitted a careful evaluation of the role(s) of vesicular transport in transmitter-specific behaviors. Accordingly, it seems appropriate at this time to present the current status of the field. In this review, we will first discuss the properties of C. elegans vesicular transporters and transporter mutants, and then explore some of the lessons and insights C. elegans research has provided to the field of vesicular transport. PMID:11099459

  14. Caenorhabditis elegans proteomics comes of age.

    PubMed

    Shim, Yhong-Hee; Paik, Young-Ki

    2010-02-01

    Caenorhabditis elegans, a free-living soil nematode, is an ideal model system for studying various physiological problems relevant to human diseases. Despite its short history, C. elegans proteomics is receiving great attention in multiple research areas, including the genome annotation, major signaling pathways (e.g. TGF-beta and insulin/IGF-1 signaling), verification of RNA interference-mediated gene targeting, aging, disease models, as well as peptidomic analysis of neuropeptides involved in behavior and locomotion. For example, a proteome-wide profiling of developmental and aging processes not only provides basic information necessary for constructing a molecular network, but also identifies important target proteins for chemical modulation. Although C. elegans has a simple body system and neural circuitry, it exhibits very complicated functions ranging from feeding to locomotion. Investigation of these functions through proteomic analysis of various C. elegans neuropeptides, some of which are not found in the predicted genome sequence, would open a new field of peptidomics. Given the importance of nematode infection in plants and mammalian pathogenesis pathways, proteomics could be applied to investigate the molecular mechanisms underlying plant- or animal-nematode pathogenesis and to identify novel antinematodal drugs. Thus, C. elegans proteomics, in combination of other molecular, biological and genetic techniques, would provide a versatile new tool box for the systematic analysis of gene functions throughout the entire life cycle of this nematode. PMID:20029841

  15. Microfluidic Devices in Advanced Caenorhabditis elegans Research.

    PubMed

    Muthaiyan Shanmugam, Muniesh; Subhra Santra, Tuhin

    2016-01-01

    The study of model organisms is very important in view of their potential for application to human therapeutic uses. One such model organism is the nematode worm, Caenorhabditis elegans. As a nematode, C. elegans have ~65% similarity with human disease genes and, therefore, studies on C. elegans can be translated to human, as well as, C. elegans can be used in the study of different types of parasitic worms that infect other living organisms. In the past decade, many efforts have been undertaken to establish interdisciplinary research collaborations between biologists, physicists and engineers in order to develop microfluidic devices to study the biology of C. elegans. Microfluidic devices with the power to manipulate and detect bio-samples, regents or biomolecules in micro-scale environments can well fulfill the requirement to handle worms under proper laboratory conditions, thereby significantly increasing research productivity and knowledge. The recent development of different kinds of microfluidic devices with ultra-high throughput platforms has enabled researchers to carry out worm population studies. Microfluidic devices primarily comprises of chambers, channels and valves, wherein worms can be cultured, immobilized, imaged, etc. Microfluidic devices have been adapted to study various worm behaviors, including that deepen our understanding of neuromuscular connectivity and functions. This review will provide a clear account of the vital involvement of microfluidic devices in worm biology. PMID:27490525

  16. Chemically defined medium and Caenorhabditis elegans

    NASA Technical Reports Server (NTRS)

    Szewczyk, Nathaniel J.; Kozak, Elena; Conley, Catharine A.

    2003-01-01

    BACKGROUND: C. elegans has been established as a powerful genetic system. Use of a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of use in large-scale growth and screening of animals. RESULTS: We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats to using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change the composition of the defined medium. CONCLUSIONS: As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  17. Mitochondrial Cell Death Pathways in Caenorhabiditis elegans.

    PubMed

    Seervi, Mahendra; Xue, Ding

    2015-01-01

    Programmed cell death is an evolutionarily conserved process essential for animal development and tissue homeostasis. Mitochondria have been demonstrated to play a central role in regulating both the activation and the execution of apoptosis. In particular, mitochondria release multiple proapoptotic factors from its intermembrane space, leading to both caspase-dependent and -independent cell death. Despite the pivotal roles of invertebrate animal models, Caenorhabiditis elegans and Drosophila melanogaster, in deciphering conserved pathways and mechanisms of programmed cell death, the importance of mitochondria to apoptosis of invertebrates remains elusive and largely unexplored. Recent studies have corroborated significant association between mitochondria and apoptosis in C. elegans, making it a thrust area of investigations. In this review, we detail the roles of mitochondrial proteins in mediating execution of cell death in C. elegans, including chromosome fragmentation, phosphatidylserine externalization, and elimination of mitochondria, and discuss the potential roles of mitochondria in the activation of C. elegans cell death. The combination of traditional powerful genetic tools and the emergence of the multiple new reverse genetic techniques, including the highly efficient CRISPR/Cas9 gene-editing method, should make C. elegans an ideal animal model for analyzing mitochondrial cell death pathways and associated regulatory mechanisms. PMID:26431563

  18. Optogenetic mutagenesis in Caenorhabditis elegans

    PubMed Central

    Noma, Kentaro; Jin, Yishi

    2015-01-01

    Reactive oxygen species (ROS) can modify and damage DNA. Here we report an optogenetic mutagenesis approach that is free of toxic chemicals and easy to perform by taking advantage of a genetically encoded ROS generator. This method relies on the potency of ROS generation by His-mSOG, the mini singlet oxygen generator, miniSOG, fused to a histone. Caenorhabditis elegans expressing His-mSOG in the germline behave and reproduce normally, without photoinduction. Following exposure to blue light, the His-mSOG animals produce progeny with a wide range of heritable phenotypes. We show that optogenetic mutagenesis by His-mSOG induces a broad spectrum of mutations including single-nucleotide variants (SNVs), chromosomal deletions, as well as integration of extrachromosomal transgenes, which complements those derived from traditional chemical or radiation mutagenesis. The optogenetic mutagenesis expands the toolbox for forward genetic screening and also provides direct evidence that nuclear ROS can induce heritable and specific genetic mutations. PMID:26632265

  19. Regulation of Body Fat in C. elegans

    PubMed Central

    Srinivasan, Supriya

    2016-01-01

    Studies conducted in C. elegans over the last decade highlight the ancient and complex origins of body fat regulation. In this critical review, I introduce the major functional approaches used to study energy balance and body fat, the lipid composition of C. elegans, the regulation of cellular fat metabolism and its transcriptional control. Next I describe the influence of the sensory nervous system on body fat and the major regulatory mechanisms that couple food perception in the nervous system with the production of energy via fat metabolism. The final section describes the opportunities for the discovery of neuroendocrine factors that control communication between the nervous system and the metabolic tissues. The coming years are expected to reveal a wealth of information on the neuroendocrine control of body fat in C. elegans. PMID:25340962

  20. Analysis of apoptosis in Caenorhabditis elegans.

    PubMed

    Lant, Benjamin; Derry, W Brent

    2014-05-01

    The nematode worm Caenorhabditis elegans has provided researchers with a wealth of information on the molecular mechanisms controlling programmed cell death (apoptosis). Its genetic tractability, optical clarity, and relatively short lifespan are key advantages for rapid assessment of apoptosis in vivo. The use of forward and reverse genetics methodology, coupled with in vivo imaging, has provided deep insights into how a multicellular organism orchestrates the self-destruction of specific cells during development and in response to exogenous stresses. Strains of C. elegans carrying mutations in the core elements of the apoptotic pathway, or in tissue-specific regulators of apoptosis, can be used for genetic analyses to reveal conserved mechanisms by which apoptosis is regulated in the somatic and reproductive (germline) tissue. Here we present an introduction to the study of apoptosis in C. elegans, including current techniques for visualization, analysis, and screening. PMID:24786497

  1. Phospholipase Cepsilon regulates ovulation in Caenorhabditis elegans.

    PubMed

    Kariya, Ken-Ichi; Bui, Yen Kim; Gao, Xianlong; Sternberg, Paul W; Kataoka, Tohru

    2004-10-01

    Phospholipase Cepsilon (PLCepsilon) is a novel class of phosphoinositide-specific PLC with unknown physiological functions. Here, we present the first genetic analysis of PLCepsilon in an intact organism, the nematode Caenorhabditis elegans. Ovulation in C. elegans is dependent on an inositol 1,4,5-trisphosphate (IP(3)) signaling pathway activated by the receptor tyrosine kinase LET-23. We generated deletion mutants of the gene, plc-1, encoding C. elegans PLCepsilon. We observed a novel ovulation phenotype whereby oocytes are trapped in the spermatheca due to delayed dilation of the spermatheca-uterine valve. The expression of plc-1 in the adult spermatheca is consistent with its involvement in regulation of ovulation. On the other hand, we failed to observe genetic interaction of plc-1 with let-23-mediated IP(3) signaling pathway genes, suggesting a complex mechanism for control of ovulation. PMID:15355798

  2. Host-Microbe Interactions in Caenorhabditis elegans

    PubMed Central

    Hou, Aixin

    2013-01-01

    A good understanding of how microbes interact with hosts has a direct bearing on our capability of fighting infectious microbial pathogens and making good use of beneficial ones. Among the model organisms used to study reciprocal actions among microbes and hosts, C. elegans may be the most advantageous in the context of its unique attributes such as the short life cycle, easiness of laboratory maintenance, and the availability of different genetic mutants. This review summarizes the recent advances in understanding host-microbe interactions in C. elegans. Although these investigations have greatly enhanced our understanding of C. elegans-microbe relationships, all but one of them involve only one or few microbial species. We argue here that more research is needed for exploring the evolution and establishment of a complex microbial community in the worm's intestine and its interaction with the host. PMID:23984180

  3. Dopamine regulates body size in Caenorhabditis elegans.

    PubMed

    Nagashima, Takashi; Oami, Eitaro; Kutsuna, Natsumaro; Ishiura, Shoichi; Suo, Satoshi

    2016-04-01

    The nervous system plays a critical role in the regulation of animal body sizes. In Caenorhabditis elegans, an amine neurotransmitter, dopamine, is required for the tactile perception of food and food-dependent behavioral changes, while its role in development is unknown. In this study, we show that dopamine negatively regulates body size through a D2-like dopamine receptor, DOP-3, in C. elegans. Dopamine alters body size without affecting food intake or developmental rate. We also found that dopamine promotes egg-laying, although the regulation of body size by dopamine was not solely caused by this effect. Furthermore, dopamine negatively regulates body size through the suppression of signaling by octopamine and Gq-coupled octopamine receptors, SER-3 and SER-6. Our results demonstrate that dopamine and octopamine regulate the body size of C. elegans and suggest a potential role for perception in addition to ingestion of food for growth. PMID:26921458

  4. [Cutaneous mold fungus granuloma from Ulocladium chartarum].

    PubMed

    Altmeyer, P; Schon, K

    1981-01-01

    Cutaneous granulomas due to the mold fungus Ulocladium chartarum (Preuss) are described in a 58 year old woman. This fungus is usually harmless for mammalian. It is thought that a consisting immunosuppression (Brill-Symmer's disease, therapy with corticosteroids) was a priming condition for the infection. The route of infection in this patient described is unknown. PMID:7194869

  5. Neurophysiological methods in C. elegans: an introduction.

    PubMed

    Schafer, William R

    2006-01-01

    The simple and well-defined structure of the C. elegans nervous system has made it an attractive model for studying the neural and genetic basis of behavior. However, the wider use physiological methods for monitoring neural activity in vivo or determining the effects of specific ion channels on neuronal function has been a relatively recent development. This chapter presents a compendium of protocols and technical reports on the current state of the art in C. elegans electrophysiology and neuroimaging. These include methods for calcium imaging in intact animals, in situ electrical recording from neurons and muscle cells, and in vitro recording from cultured neurons and oocytes. PMID:18050439

  6. Regulation of metabolism in Caenorhabditis elegans longevity.

    PubMed

    Gallo, Marco; Riddle, Donald L

    2010-01-01

    The nematode Caenorhabditis elegans is a favorite model for the study of aging. A wealth of genetic and genomic studies show that metabolic regulation is a hallmark of life-span modulation. A recent study in BMC Biology identifying metabolic signatures for longevity suggests that amino-acid pools may be important in longevity. PMID:20156326

  7. The invertebrate Caenorhabditis elegans biosynthesizes ascorbate

    PubMed Central

    Patananan, Alexander N.; Budenholzer, Lauren M.; Pedraza, Maria E.; Torres, Eric R.; Adler, Lital N.; Clarke, Steven G.

    2015-01-01

    L-ascorbate, commonly known as vitamin C, serves as an antioxidant and cofactor essential for many biological processes. Distinct ascorbate biosynthetic pathways have been established for animals and plants, but little is known about the presence or synthesis of this molecule in invertebrate species. We have investigated ascorbate metabolism in the nematode Caenorhabditis elegans, where this molecule would be expected to play roles in oxidative stress resistance and as cofactor in collagen and neurotransmitter synthesis. Using high-performance liquid chromatography and gas-chromatography mass spectrometry, we determined that ascorbate is present at low amounts in the egg stage, L1 larvae, and mixed animal populations, with the egg stage containing the highest concentrations. Incubating C. elegans with precursor molecules necessary for ascorbate synthesis in plants and animals did not significantly alter ascorbate levels. Furthermore, bioinformatic analyses did not support the presence in C. elegans of either the plant or the animal biosynthetic pathway. However, we observed the complete 13C-labeling of ascorbate when C. elegans was grown with 13C-labeled Escherichia coli as a food source. These results support the hypothesis that ascorbate biosynthesis in invertebrates may proceed by a novel pathway and lay the foundation for a broader understanding of its biological role. PMID:25668719

  8. Guidelines for monitoring autophagy in Caenorhabditis elegans

    PubMed Central

    Zhang, Hong; Chang, Jessica T; Guo, Bin; Hansen, Malene; Jia, Kailiang; Kovács, Attila L; Kumsta, Caroline; Lapierre, Louis R; Legouis, Renaud; Lin, Long; Lu, Qun; Meléndez, Alicia; O'Rourke, Eyleen J; Sato, Ken; Sato, Miyuki; Wang, Xiaochen; Wu, Fan

    2015-01-01

    The cellular recycling process of autophagy has been extensively characterized with standard assays in yeast and mammalian cell lines. In multicellular organisms, numerous external and internal factors differentially affect autophagy activity in specific cell types throughout the stages of organismal ontogeny, adding complexity to the analysis of autophagy in these metazoans. Here we summarize currently available assays for monitoring the autophagic process in the nematode C. elegans. A combination of measuring levels of the lipidated Atg8 ortholog LGG-1, degradation of well-characterized autophagic substrates such as germline P granule components and the SQSTM1/p62 ortholog SQST-1, expression of autophagic genes and electron microscopy analysis of autophagic structures are presently the most informative, yet steady-state, approaches available to assess autophagy levels in C. elegans. We also review how altered autophagy activity affects a variety of biological processes in C. elegans such as L1 survival under starvation conditions, dauer formation, aging, and cell death, as well as neuronal cell specification. Taken together, C. elegans is emerging as a powerful model organism to monitor autophagy while evaluating important physiological roles for autophagy in key developmental events as well as during adulthood. PMID:25569839

  9. Cytological Analysis of Meiosis in Caenorhabditis elegans

    PubMed Central

    Phillips, Carolyn M.; McDonald, Kent L.; Dernburg, Abby F.

    2011-01-01

    The nematode Caenorhabditis elegans has emerged as an informative experimental system for analysis of meiosis, in large part because of the advantageous physical organization of meiotic nuclei as a gradient of stages within the germline. Here we provide tools for detailed observational studies of cells within the worm gonad, including techniques for light and electron microscopy. PMID:19685325

  10. A Protocol to Infect Caenorhabditis elegans with Salmonella typhimurium

    PubMed Central

    Zhang, Jiuli; Jia, Kailiang

    2014-01-01

    In the last decade, C. elegans has emerged as an invertebrate organism to study interactions between hosts and pathogens, including the host defense against gram-negative bacterium Salmonella typhimurium. Salmonella establishes persistent infection in the intestine of C. elegans and results in early death of infected animals. A number of immunity mechanisms have been identified in C. elegans to defend against Salmonella infections. Autophagy, an evolutionarily conserved lysosomal degradation pathway, has been shown to limit the Salmonella replication in C. elegans and in mammals. Here, a protocol is described to infect C. elegans with Salmonella typhimurium, in which the worms are exposed to Salmonella for a limited time, similar to Salmonella infection in humans. Salmonella infection significantly shortens the lifespan of C. elegans. Using the essential autophagy gene bec-1 as an example, we combined this infection method with C. elegans RNAi feeding approach and showed this protocol can be used to examine the function of C. elegans host genes in defense against Salmonella infection. Since C. elegans whole genome RNAi libraries are available, this protocol makes it possible to comprehensively screen for C. elegans genes that protect against Salmonella and other intestinal pathogens using genome-wide RNAi libraries. PMID:24998902

  11. Hormetic effect of methylmercury on Caenorhabditis elegans

    SciTech Connect

    Helmcke, Kirsten J. Aschner, Michael

    2010-10-15

    Research has demonstrated the toxic effects of methylmercury (MeHg), yet molecular mechanisms underlying its toxicity are not completely understood. Caenorhabditis elegans (C. elegans) offers a unique biological model to explore mechanisms of MeHg toxicity given many advantages associated with its ease of use and genetic power. Since our previous work indicated neurotoxic resistance of C. elegans to MeHg, the present study was designed to examine molecular mechanisms associated with this resistance. We hypothesized MeHg would induce expression of gst, hsp or mtl in vivo since glutathione (GSH), heat shock proteins (HSPs), and metallothioneins (MTs) have shown involvement in MeHg toxicity. Our studies demonstrated a modest, but significant increase in fluorescence in gst-4::GFP and mtl-1::GFP strains at an acute, low L1 MeHg exposure, whereas chronic L4 MeHg exposure induced expression of gst-4::GFP and hsp-4::GFP. Knockout gst-4 animals showed no alterations in lethality sensitivity compared to wildtype animals whereas mtl knockouts displayed increased sensitivity to MeHg exposure. GSH levels were increased by acute MeHg treatment and depleted with chronic exposure. We also demonstrate that MeHg induces hormesis, a phenotype whereby a sublethal exposure to MeHg rendered C. elegans resistant to subsequent exposure to the organometal. The involvement of gst-4, hsp-4, mtl-1, and mtl-2 in hormesis was examined. An increase in gst-4::GFP expression after a low-dose acute exposure to MeHg indicated that gst-4 may be involved in this response. Our results implicate GSH, HSPs, and MTs in protecting C. elegans from MeHg toxicity and show a potential role of gst-4 in MeHg-induced hormesis.

  12. Hormetic effect of methylmercury on Caenorhabditis elegans.

    PubMed

    Helmcke, Kirsten J; Aschner, Michael

    2010-10-15

    Research has demonstrated the toxic effects of methylmercury (MeHg), yet molecular mechanisms underlying its toxicity are not completely understood. Caenorhabditis elegans (C. elegans) offers a unique biological model to explore mechanisms of MeHg toxicity given many advantages associated with its ease of use and genetic power. Since our previous work indicated neurotoxic resistance of C. elegans to MeHg, the present study was designed to examine molecular mechanisms associated with this resistance. We hypothesized MeHg would induce expression of gst, hsp or mtl in vivo since glutathione (GSH), heat shock proteins (HSPs), and metallothioneins (MTs) have shown involvement in MeHg toxicity. Our studies demonstrated a modest, but significant increase in fluorescence in gst-4::GFP and mtl-1::GFP strains at an acute, low L1 MeHg exposure, whereas chronic L4 MeHg exposure induced expression of gst-4::GFP and hsp-4::GFP. Knockout gst-4 animals showed no alterations in lethality sensitivity compared to wildtype animals whereas mtl knockouts displayed increased sensitivity to MeHg exposure. GSH levels were increased by acute MeHg treatment and depleted with chronic exposure. We also demonstrate that MeHg induces hormesis, a phenotype whereby a sublethal exposure to MeHg rendered C. elegans resistant to subsequent exposure to the organometal. The involvement of gst-4, hsp-4, mtl-1, and mtl-2 in hormesis was examined. An increase in gst-4::GFP expression after a low-dose acute exposure to MeHg indicated that gst-4 may be involved in this response. Our results implicate GSH, HSPs, and MTs in protecting C. elegans from MeHg toxicity and show a potential role of gst-4 in MeHg-induced hormesis. PMID:20691719

  13. Granulicatella elegans Causing Periorbital Infection During Orthodontic Treatment.

    PubMed

    Kim, Yong Joon; Choi, Bo Mi; Choi, Kyung Seek

    2016-01-01

    Granulicatella elegans is a normal component of the oral flora and is an unusual causative agent of infective endocarditis. A case of G. elegans periorbital infection of the eyelid after dental treatment is reported. A healthy 35-year-old man presented with painful swelling of the left upper eyelid. He was empirically treated with oral amoxicillin for 1 week. He presented 3 months later with the same clinical features. G. elegans and Staphylococcus epidermidis were identified in bacterial cultures from wound aspirates. Probable relapse of periorbital infection was successfully treated with a 6-week course of oral amoxicillin. This is the first reported case of a non-bloodstream infection caused by G. elegans. Clinicians should be aware of G. elegans as an unusual causative agent of periorbital infection. Within the limitations of this case report, prolonged antibiotic therapy is recommended for a G. elegans periorbital infection to minimize the risk of relapse. PMID:25105523

  14. Chemical detoxification of small molecules by C. elegans

    PubMed Central

    Stupp, Gregory S.; von Reuss, Stephan H.; Izrayelit, Yevgeniy; Ajredini, Ramadan; Schroeder, Frank C.; Edison, Arthur S.

    2012-01-01

    Caenorhabditis elegans lives in compost and decaying fruit, eats bacteria and is exposed to pathogenic microbes. We show that C. elegans is able to modify diverse microbial small-molecule toxins via both O-and N-glucosylation as well as unusual 3′-O-phosphorylation of the resulting glucosides. The resulting glucosylated derivatives have significantly reduced toxicity to C. elegans, suggesting that these chemical modifications represent a general mechanism for worms to detoxify their environments. PMID:23163740

  15. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities.

    PubMed

    Lou, Jingfeng; Yu, Ruiting; Wang, Xiaohan; Mao, Ziling; Fu, Linyun; Liu, Yang; Zhou, Ligang

    2016-01-01

    One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75μg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27μg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18μg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17μg/mL and 74.62μg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms. PMID:26887231

  16. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities

    PubMed Central

    Lou, Jingfeng; Yu, Ruiting; Wang, Xiaohan; Mao, Ziling; Fu, Linyun; Liu, Yang; Zhou, Ligang

    2016-01-01

    One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75 μg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27 μg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18 μg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17 μg/mL and 74.62 μg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms. PMID:26887231

  17. Why are there males in the hermaphroditic species Caenorhabditis elegans?

    PubMed Central

    Chasnov, J R; Chow, King L

    2002-01-01

    The free-living nematode worm Caenorhabditis elegans reproduces primarily as a self-fertilizing hermaphrodite, yet males are maintained in wild-type populations at low frequency. To determine the role of males in C. elegans, we develop a mathematical model for the genetic system of hermaphrodites that can either self-fertilize or be fertilized by males and we perform laboratory observations and experiments on both C. elegans and a related dioecious species C. remanei. We show that the mating efficiency of C. elegans is poor compared to a dioecious species and that C. elegans males are more attracted to C. remanei females than they are to their conspecific hermaphrodites. We postulate that a genetic mutation occurred during the evolution of C. elegans hermaphrodites, resulting in the loss of an attracting sex pheromone present in the ancestor of both C. elegans and C. remanei. Our findings suggest that males are maintained in C. elegans because of the particular genetic system inherited from its dioecious ancestor and because of nonadaptive spontaneous nondisjunction of sex chromosomes, which occurs during meiosis in the hermaphrodite. A theoretical argument shows that the low frequency of male mating observed in C. elegans can support male-specific genes against mutational degeneration. This results in the continuing presence of functional males in a 99.9% hermaphroditic species in which outcrossing is disadvantageous to hermaphrodites. PMID:11901116

  18. C. elegans in high-throughput drug discovery

    PubMed Central

    O’Reilly, Linda P.; Luke, Cliff J.; Perlmutter, David H.; Silverman, Gary A.; Pak, Stephen C.

    2014-01-01

    C. elegans has proven to be a useful model organism for investigating molecular and cellular aspects of numerous human diseases. More recently, investigators have explored the use of this organism as a tool for drug discovery. Although earlier drug screens were labor-intensive and low in throughput, recent advances in high-throughput liquid workflows, imaging platforms and data analysis software have made C. elegans a viable option for automated high-throughput drug screens. This review will outline the evolution of C. elegans-based drug screening, discuss the inherent challenges of using C. elegans, and highlight recent technological advances that have paved the way for future drug screens. PMID:24333896

  19. Measurements of behavioral quiescence in Caenorhabditis elegans.

    PubMed

    Nagy, Stanislav; Raizen, David M; Biron, David

    2014-08-01

    The nematode Caenorhabditis (C.) elegans, a long time work horse for behavioral genetic studies of locomotion, has recently been studied for quiescent behavior. Methods previously established for the study of C. elegans locomotion are not well-suited for the study of quiescent behavior. We describe in detail two computer vision approaches to distinguish quiescent from movement bouts focusing on the behavioral quiescence that occurs during fourth larval stage lethargus, a transition stage between the larva and the adult. The first is the frame subtraction method, which consists of subtraction of temporally adjacent images as a sensitive way to detect motion. The second, which is more computationally intensive, is the posture analysis method, which consists of analysis of the rate of local angle change of the animal's body. Quiescence measurements should be done continuously while minimizing sensory perturbation of the animal. PMID:24642199

  20. Mechanisms of iron metabolism in Caenorhabditis elegans

    PubMed Central

    Anderson, Cole P.; Leibold, Elizabeth A.

    2014-01-01

    Iron is involved in many biological processes essential for sustaining life. In excess, iron is toxic due to its ability to catalyze the formation of free radicals that damage macromolecules. Organisms have developed specialized mechanisms to tightly regulate iron uptake, storage and efflux. Over the past decades, vertebrate model organisms have led to the identification of key genes and pathways that regulate systemic and cellular iron metabolism. This review provides an overview of iron metabolism in the roundworm Caenorhabditis elegans and highlights recent studies on the role of hypoxia and insulin signaling in the regulation of iron metabolism. Given that iron, hypoxia and insulin signaling pathways are evolutionarily conserved, C. elegans provides a genetic model organism that promises to provide new insights into mechanisms regulating mammalian iron metabolism. PMID:24904417

  1. Proteomics applications in Caenorhabditis elegans research.

    PubMed

    Husson, Steven J; Moyson, Sofie; Valkenborg, Dirk; Baggerman, Geert; Mertens, Inge

    2015-12-25

    The free-living nematode Caenorhabditis elegans is one of the most studied models in a wide variety of research fields with applications in agro- or pharmaceutical industries. It has been used for the development of new anthelminthic drugs and was proven to yield key insights in neurodegenerative diseases and metabolic syndromes. Due to its suitability for high-throughput genetic screens, efficiency for RNA interference approaches and the availability of thousands of mutants, most studies were carried out at the genetic level. However, determining the cellular function of each gene product remains an unfinished goal in this post-genomic era. A systems biology approach focusing on the actual gene products (i.e. proteins) can help unraveling this puzzle. A fundamental pillar in this research is mass spectrometry-based proteomics. We here provide an in-depth overview of proteomics-related studies in C. elegans research, with special emphasis on the methodologies and biological applications. PMID:26585491

  2. Biogenic magnetite in the nematode caenorhabditis elegans.

    PubMed Central

    Cranfield, Charles G; Dawe, Adam; Karloukovski, Vassil; Dunin-Borkowski, Rafal E; de Pomerai, David; Dobson, Jon

    2004-01-01

    The nematode Caenorhabditis elegans is widely used as a model system in biological research. Recently, examination of the production of heat-shock proteins in this organism in response to mobile phone-type electromagnetic field exposure produced the most robust demonstration to date of a non-thermal, deleterious biological effect. Though these results appear to be a sound demonstration of non-thermal bioeffects, to our knowledge, no mechanism has been proposed to explain them. We show, apparently for the first time, that biogenic magnetite, a ferrimagnetic iron oxide, is present in C. elegans. Its presence may have confounding effects on experiments involving electromagnetic fields as well as implications for the use of this nematode as a model system for iron biomineralization in multi-cellular organisms. PMID:15801597

  3. Locomotion of C elegans in structured environments

    NASA Astrophysics Data System (ADS)

    Majmudar, Trushant; Keaveny, Eric; Shelley, Michael; Zhang, Jun

    2011-11-01

    We have established a combined experimental and numerical platform to study the swimming dynamics of an undulating worm in structured environments (fluid-filled micro-pillar arrays). We have shown that the worm (C. elegans) swims with different velocity and frequency depending on the lattice spacing and our purely mechanistic simulations (elastically linked bead-chain) reproduce the experimental results qualitatively and quantitatively, including ``life-like'' trajectories the worm exhibits. We build upon this platform to investigate more complex environments, such as linear and radial lattices, with gradients in spacing. In addition, we study C. elegans mutants to investigate the role of length of the worm, frequency of undulations, and mechano-sensation on the resultant dynamics. We also examine the worm moving through a lattice with random distribution of obstacles - a model soil-like environment. Our combined experimental and simulations approach allows us to gain insights into the dynamics of locomotion of undulating microorganisms in realistic complex environments.

  4. The laboratory domestication of Caenorhabditis elegans

    PubMed Central

    Sterken, Mark G.; Snoek, L. Basten; Kammenga, Jan E.; Andersen, Erik C.

    2015-01-01

    Model organisms are of great importance to understanding basic biology and to making advances in biomedical research. However, the influence of laboratory cultivation on these organisms is underappreciated, especially how that environment can affect research outcomes. Recent experiments led to insights into how the widely used laboratory reference strain of the nematode Caenorhabditis elegans compares to natural strains. Here, we describe potential selective pressures that led to fixation of laboratory-derived alleles for the genes npr-1, glb-5, and nath-10. These alleles influence a large number of traits, resulting in behaviors that affect experimental interpretations. Furthermore, strong phenotypic effects caused by these laboratory-derived alleles hinder the discovery of natural alleles. We highlight strategies to reduce the influences of laboratory-derived alleles and to harness the full power of C. elegans. PMID:25804345

  5. Dietary choice behavior in Caenorhabditis elegans.

    PubMed

    Shtonda, Boris Borisovich; Avery, Leon

    2006-01-01

    Animals have evolved diverse behaviors that serve the purpose of finding food in the environment. We investigated the food seeking strategy of the soil bacteria-eating nematode Caenorhabditis elegans. C. elegans bacterial food varies in quality: some species are easy to eat and support worm growth well, while others do not. We show that worms exhibit dietary choice: they hunt for high quality food and leave hard-to-eat bacteria. This food seeking behavior is enhanced in animals that have already experienced good food. When hunting for good food, worms alternate between two modes of locomotion, known as dwelling: movement with frequent stops and reversals; and roaming: straight rapid movement. On good food, roaming is very rare, while on bad food it is common. Using laser ablations and mutant analysis, we show that the AIY neurons serve to extend roaming periods, and are essential for efficient food seeking. PMID:16354781

  6. Lamin-Binding Proteins in Caenorhabditis elegans.

    PubMed

    Dobrzynska, Agnieszka; Askjaer, Peter; Gruenbaum, Yosef

    2016-01-01

    The nuclear lamina, composed of lamins and numerous lamin-associated proteins, is required for mechanical stability, mechanosensing, chromatin organization, developmental gene regulation, mRNA transcription, DNA replication, nuclear assembly, and nuclear positioning. Mutations in lamins or lamin-binding proteins cause at least 18 distinct human diseases that affect specific tissues such as muscle, adipose, bone, nerve, or skin, and range from muscular dystrophies to lipodystrophy, peripheral neuropathy, or accelerated aging. Caenorhabditis elegans has unique advantages in studying lamin-binding proteins. These advantages include the low complexity of genes encoding lamin and lamin-binding proteins, advanced transgenic techniques, simple application of RNA interference, sophisticated genetic strategies, and a large collection of mutant lines. This chapter provides detailed and comprehensive protocols for the genetic and phenotypic analysis of lamin-binding proteins in C. elegans. PMID:26778571

  7. [C. elegans: of neurons and genes].

    PubMed

    Gally, Christelle; Bessereau, Jean-Louis

    2003-01-01

    The human brain contains 100 billion neurons and probably one thousand times more synapses. Such a system can be analyzed at different complexity levels, from cognitive functions to molecular structure of ion channels. However, it remains extremely difficult to establish links between these different levels. An alternative strategy relies on the use of much simpler animals that can be easily manipulated. In 1974, S. Brenner introduced the nematode Caenorhabditis elegans as a model system. This worm has a simple nervous system that only contains 302 neurons and about 7,000 synapses. Forward genetic screens are powerful tools to identify genes required for specific neuron functions and behaviors. Moreover, studies of mutant phenotypes can identify the function of a protein in the nervous system. The data that have been obtained in C. elegans demonstrate a fascinating conservation of the molecular and cellular biology of the neuron between worms and mammals through more than 550 million years of evolution. PMID:12942444

  8. Programmed Cell Death During Caenorhabditis elegans Development.

    PubMed

    Conradt, Barbara; Wu, Yi-Chun; Xue, Ding

    2016-08-01

    Programmed cell death is an integral component of Caenorhabditis elegans development. Genetic and reverse genetic studies in C. elegans have led to the identification of many genes and conserved cell death pathways that are important for the specification of which cells should live or die, the activation of the suicide program, and the dismantling and removal of dying cells. Molecular, cell biological, and biochemical studies have revealed the underlying mechanisms that control these three phases of programmed cell death. In particular, the interplay of transcriptional regulatory cascades and networks involving multiple transcriptional regulators is crucial in activating the expression of the key death-inducing gene egl-1 and, in some cases, the ced-3 gene in cells destined to die. A protein interaction cascade involving EGL-1, CED-9, CED-4, and CED-3 results in the activation of the key cell death protease CED-3, which is tightly controlled by multiple positive and negative regulators. The activation of the CED-3 caspase then initiates the cell disassembly process by cleaving and activating or inactivating crucial CED-3 substrates; leading to activation of multiple cell death execution events, including nuclear DNA fragmentation, mitochondrial elimination, phosphatidylserine externalization, inactivation of survival signals, and clearance of apoptotic cells. Further studies of programmed cell death in C. elegans will continue to advance our understanding of how programmed cell death is regulated, activated, and executed in general. PMID:27516615

  9. Toxicological Effects of Fullerenes on Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Schomaker, Justin; Snook, Renee; Howell, Carina

    2014-03-01

    The nematode species Caenorhabditis elegans is a useful genetic model organism due to its simplicity and the substantial molecular, genetic, and developmental knowledge about the species. In this study, this species was used to test the toxicological effects of C60 fullerene nanoparticles. In previous studies using rats, a solution of C60 fullerenes in olive oil proved to extend the life of the subjects. The purpose of this experiment was to subject C. elegans to varying concentrations of C60 fullerenes and observe their toxicological effects. Initial findings indicate a link between fullerene exposure and enlargement of the vulva as well as the formation of a small nodule at the base of the tail in some individuals. While the fullerenes are not lethally toxic in C. elegans, results will be presented that pertain to changes in life span and progeny of the nematodes exposed to varying concentrations of fullerenes as well as the mechanisms of toxicity. High magnification imaging via SEM and/or AFM will be used to characterize the fullerene nanoparticles. Testing the toxicity of fullerenes in a wide variety of organisms will lead to a more complete understanding of the effects of fullerenes on living organisms to ultimately understand their effects in humans. This work was supported by National Science Foundation grants DUE-1058829, DMR-0923047, DUE-0806660 and Lock Haven FPDC grants.

  10. Control of Neuronal Network in Caenorhabditis elegans

    PubMed Central

    Badhwar, Rahul; Bagler, Ganesh

    2015-01-01

    Caenorhabditis elegans, a soil dwelling nematode, is evolutionarily rudimentary and contains only ∼ 300 neurons which are connected to each other via chemical synapses and gap junctions. This structural connectivity can be perceived as nodes and edges of a graph. Controlling complex networked systems (such as nervous system) has been an area of excitement for mankind. Various methods have been developed to identify specific brain regions, which when controlled by external input can lead to achievement of control over the state of the system. But in case of neuronal connectivity network the properties of neurons identified as driver nodes is of much importance because nervous system can produce a variety of states (behaviour of the animal). Hence to gain insight on the type of control achieved in nervous system we implemented the notion of structural control from graph theory to C. elegans neuronal network. We identified ‘driver neurons’ which can provide full control over the network. We studied phenotypic properties of these neurons which are referred to as ‘phenoframe’ as well as the ‘genoframe’ which represents their genetic correlates. We find that the driver neurons are primarily motor neurons located in the ventral nerve cord and contribute to biological reproduction of the animal. Identification of driver neurons and its characterization adds a new dimension in controllability of C. elegans neuronal network. This study suggests the importance of driver neurons and their utility to control the behaviour of the organism. PMID:26413834

  11. CLC chloride channels in Caenorhabditis elegans.

    PubMed

    Schriever, A M; Friedrich, T; Pusch, M; Jentsch, T J

    1999-11-26

    The genome of the nematode Caenorhabditis elegans encodes six putative chloride channels (CeCLC-1 through CeCLC-6) that represent all three known branches of the mammalian CLC gene family. Using promoter fragments to drive the expression of the green fluorescent protein, CeCLC-2, -3, and -4 expression was studied in transgenic C. elegans. CeCLC-4 was specifically expressed in the large H-shaped excretory cell, where it was co-expressed with CeCLC-3, which is also expressed in other cells, including neurons, muscles, and epithelial cells. Also, CeCLC-2 was expressed in several cells of the nervous system, intestinal cells, and vulval muscle cells. Similar to mammalian CLC proteins, only two nematode CLC channels elicited detectable plasma membrane currents in Xenopus oocytes. CeCLC-3 currents were inwardly rectifying and were activated by positive prepulses. Its complex gating behavior can be explained by two gates, at least one of which depends on extracellular anions. In this respect it resembles some mammalian chloride channels with which it also shares a preference of chloride over iodide. C. elegans thus provides new opportunities to understand common mechanisms underlying structure and function in CLC channels and will allow for a genetic dissection of chloride channels in this simple model organism. PMID:10567397

  12. Katz model prediction of Caenorhabditis elegans mutagenesis on STS-42

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.; Katz, Robert; Badhwar, Gautam D.

    1992-01-01

    Response parameters that describe the production of recessive lethal mutations in C. elegans from ionizing radiation are obtained with the Katz track structure model. The authors used models of the space radiation environment and radiation transport to predict and discuss mutation rates for C. elegans on the IML-1 experiment aboard STS-42.

  13. CRISPR/Cas9-targeted mutagenesis in Caenorhabditis elegans.

    PubMed

    Waaijers, Selma; Portegijs, Vincent; Kerver, Jana; Lemmens, Bennie B L G; Tijsterman, Marcel; van den Heuvel, Sander; Boxem, Mike

    2013-11-01

    The generation of genetic mutants in Caenorhabditis elegans has long relied on the selection of mutations in large-scale screens. Directed mutagenesis of specific loci in the genome would greatly speed up analysis of gene function. Here, we adapt the CRISPR/Cas9 system to generate mutations at specific sites in the C. elegans genome. PMID:23979586

  14. Caenorhabditis elegans chemical biology: lessons from small molecules

    Technology Transfer Automated Retrieval System (TEKTRAN)

    How can we complement Caenorhabditis elegans genomics and proteomics with a comprehensive structural and functional annotation of its metabolome? Several lines of evidence indicate that small molecules of largely undetermined structure play important roles in C. elegans biology, including key pathw...

  15. Fungus-insect gall of Phlebopus portentosus.

    PubMed

    Zhang, Chun-Xia; He, Ming-Xia; Cao, Yang; Liu, Jing; Gao, Feng; Wang, Wen-Bing; Ji, Kai-Ping; Shao, Shi-Cheng; Wang, Yun

    2015-01-01

    Phlebopus portentosus is a popular edible wild mushroom found in the tropical Yunnan, China, and northern Thailand. In its natural habitats, a gall often has been found on some plant roots, around which fungal fruiting bodies are produced. The galls are different from common insect galls in that their cavity walls are not made from plant tissue but rather from the hyphae of P. portentosus. Therefore we have termed this phenomenon "fungus-insect gall". Thus far six root mealy bug species in the family Pseudococcidae that form fungus-insect galls with P. portentosus have been identified: Formicococcus polysperes, Geococcus satellitum, Planococcus minor, Pseudococcus cryptus, Paraputo banzigeri and Rastrococcus invadens. Fungus-insect galls were found on the roots of more than 21 plant species, including Delonix regia, Citrus maxima, Coffea arabica and Artocarpus heterophyllus. Greenhouse inoculation trials showed that fungus-insect galls were found on the roots of A. heterophyllus 1 mo after inoculation. The galls were subglobose to globose, fulvous when young and became dark brown at maturation. Each gall harbored one or more mealy bugs and had a chimney-like vent for ventilation and access to the gall. The cavity wall had three layers. Various shaped mealy bug wax deposits were found inside the wall. Fungal hyphae invaded the epidermis of plant roots and sometimes even the cortical cells during the late stage of gall development. The identity of the fungus inside the cavity was confirmed by molecular methods. PMID:25344264

  16. The Caenorhabiditis elegans model as a reliable tool in neurotoxicology

    PubMed Central

    Avila, Daiana; Helmcke, Kirsten; Aschner, Michael

    2016-01-01

    Caenorhabiditis elegans (C. elegans) offers an attractive experimental platform as it has a short life cycle, is inexpensive to maintain and most importantly has high degree of evolutionary conservation with higher eukaryotes. Understanding the contribution of inherent genes that regulate neurotoxicity and antioxidant stress responses in the worm provides critical insight into mechanisms of mammalian neurotoxicity. The C. elegans model readily enables multi-gene approach, allowing for combinatorial genetic variation to be studied within the context of the influence of multigenic polymorphisms in environmental risk and vulnerability. This review provides a synopsis of recent studies on metal and pesticides toxicity in C. elegans, highlighting the utility of the model system in understanding molecular mechanisms that underlie developmental, reproductive and neuronal damage. The continuation of these investigations combining basic toxicological experimentation with novel genetic and high throughput methods will continue to make C. elegans an invaluable tool for future research, providing insight into molecular and cellular mechanisms of toxicity. PMID:21148196

  17. The Caenorhabditis elegans lipidome: A primer for lipid analysis in Caenorhabditis elegans.

    PubMed

    Witting, Michael; Schmitt-Kopplin, Philippe

    2016-01-01

    Lipids play important roles in biology, ranging from building blocks of membranes to signaling lipids. The nematode and model organism Caenorhabditis elegans has been used to explore lipid metabolism and several techniques for their analysis have been employed. These techniques include different possibilities ranging from visualization of lipid droplets, analysis of total fatty acids to analysis of complex lipids using lipidomics approaches. Lipidomics evolved from metabolomics, the latest off-spring of the "omics"-technologies and aims to characterize the lipid content of a given organism or system. Although being an extensively studied model organism, only a few applications of lipidomics to C. elegans have been reported to far, but the number is steadily increasing with more applications expected in the near future. This review gives an overview on the C. elegans lipidome, lipid classes it contains and ways to analyze them. It serves as primer for scientists interested in studying lipids in this model organism and list methods used so far and what information can be derived from them. Lastly, challenges and future (methodological) research directions, together with new methods potentially useful for C. elegans lipid research are discussed. PMID:26072113

  18. An unusual niche for an opportunistic fungus.

    PubMed

    Rodríguez-del Valle, N; Quigdley, L; Silva-Ruíz, S A

    1991-02-01

    An acrylic on canvas painting from the collection of the Institute of Puerto Rico Culture was found to be stained with light brown spots. Under ultraviolet light it was evident that these spots covered the entire painting. Scotch tape samples from different areas of the painting were taken. In almost all of these samples, septated hyphae were observed to surround the canvas fibers and in most of them, spiny or rough-surfaced conidia were also observed. A sample from the canvas which was incubated over a Sabourand agar plate yielded a fungus very similar to the one observed in the tape samples after subculturing in potato dextrose agar. Slide cultures and culture characteristics provided evidence that this fungus was a species of Scopulariopsis. This fungus has been implicated in human disease and in this case, it was the cause of the deterioration of the painting. PMID:2043232

  19. Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis

    PubMed Central

    Oh, Dong-Chan; Poulsen, Michael; Currie, Cameron R.; Clardy, Jon

    2009-01-01

    Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective antibiotics to defend that fungus from specialized fungal parasites. In the first system to be analyzed at the molecular level, the bacterium associated with the ant Apterostigma dentigerum produces dentigerumycin, a cyclic depsipeptide with highly modified amino acids, to selectively inhibit the parasitic fungus (Escovopsis sp.). PMID:19330011

  20. Microbial light-activatable proton pumps as neuronal inhibitors to functionally dissect neuronal networks in C. elegans.

    PubMed

    Husson, Steven J; Liewald, Jana F; Schultheis, Christian; Stirman, Jeffrey N; Lu, Hang; Gottschalk, Alexander

    2012-01-01

    Essentially any behavior in simple and complex animals depends on neuronal network function. Currently, the best-defined system to study neuronal circuits is the nematode Caenorhabditis elegans, as the connectivity of its 302 neurons is exactly known. Individual neurons can be activated by photostimulation of Channelrhodopsin-2 (ChR2) using blue light, allowing to directly probe the importance of a particular neuron for the respective behavioral output of the network under study. In analogy, other excitable cells can be inhibited by expressing Halorhodopsin from Natronomonas pharaonis (NpHR) and subsequent illumination with yellow light. However, inhibiting C. elegans neurons using NpHR is difficult. Recently, proton pumps from various sources were established as valuable alternative hyperpolarizers. Here we show that archaerhodopsin-3 (Arch) from Halorubrum sodomense and a proton pump from the fungus Leptosphaeria maculans (Mac) can be utilized to effectively inhibit excitable cells in C. elegans. Arch is the most powerful hyperpolarizer when illuminated with yellow or green light while the action spectrum of Mac is more blue-shifted, as analyzed by light-evoked behaviors and electrophysiology. This allows these tools to be combined in various ways with ChR2 to analyze different subsets of neurons within a circuit. We exemplify this by means of the polymodal aversive sensory ASH neurons, and the downstream command interneurons to which ASH neurons signal to trigger a reversal followed by a directional turn. Photostimulating ASH and subsequently inhibiting command interneurons using two-color illumination of different body segments, allows investigating temporal aspects of signaling downstream of ASH. PMID:22815873

  1. Open-Ended Experimentation with the Fungus Pilobolus.

    ERIC Educational Resources Information Center

    Coble, Charles R.; Bland, Charles E.

    This paper describes open-ended experimentation with the fungus Pilobolus for laboratory work by high school students. The fungus structure and reproduction is described and sources of the fungus are suggested. Four areas for investigation are suggested: the effect of a diffuse light source, the effect of a point light source, the effect of light…

  2. Immunoglobulin superfamily proteins in Caenorhabditis elegans.

    PubMed

    Teichmann, S A; Chothia, C

    2000-03-10

    The predicted proteins of the genome of Caenorhabditis elegans were analysed by various sequence comparison methods to identify the repertoire of proteins that are members of the immunoglobulin superfamily (IgSF). The IgSF is one of the largest families of protein domain in this genome and likely to be one of the major families in other multicellular eukaryotes too. This is because members of the superfamily are involved in a variety of functions including cell-cell recognition, cell-surface receptors, muscle structure and, in higher organisms, the immune system. Sixty-four proteins with 488 I set IgSF domains were identified largely by using Hidden Markov models. The domain architectures of the protein products of these 64 genes are described. Twenty-one of these had been characterised previously. We show that another 25 are related to proteins of known function. The C. elegans IgSF proteins can be classified into five broad categories: muscle proteins, protein kinases and phosphatases, three categories of proteins involved in the development of the nervous system, leucine-rich repeat containing proteins and proteins without homologues of known function, of which there are 18. The 19 proteins involved in nervous system development that are not kinases or phosphatases are homologues of neuroglian, axonin, NCAM, wrapper, klingon, ICCR and nephrin or belong to the recently identified zig gene family. Out of the set of 64 genes, 22 are on the X chromosome. This study should be seen as an initial description of the IgSF repertoire in C. elegans, because the current gene definitions may contain a number of errors, especially in the case of long sequences, and there may be IgSF genes that have not yet been detected. However, the proteins described here do provide an overview of the bulk of the repertoire of immunoglobulin superfamily members in C. elegans, a framework for refinement and extension of the repertoire as gene and protein definitions improve, and the basis

  3. Caenorhabditis elegans as a model for obesity research.

    PubMed

    Zheng, J; Greenway, F L

    2012-02-01

    Caenorhabditis elegans (C. elegans) is a small nematode that conserves 65% of the genes associated with human disease, has a 21-day lifespan, reproductive cycles of 3 days, large brood sizes, lives in an agar dish and does not require committee approvals for experimentation. Research using C. elegans is encouraged and a Caenorhabditis Genetics Center (CGC, Minnesota) is funded by the National Institutes of Health-National Center for Research Resources. Many genetically manipulated strains of C. elegans are available at nominal cost from the CGC. Studies using the C. elegans model have explored insulin signaling, response to dietary glucose, the influence of serotonin on obesity, satiety, feeding and hypoxia-associated illnesses. C. elegans has also been used as a model to evaluate potential obesity therapeutics, explore the mechanisms behind single gene mutations related to obesity and to define the mechanistic details of fat metabolism. Obesity now affects a third of the US population and is becoming a progressively more expensive public health problem. Faster and less expensive methods to reach more effective treatments are clearly needed. We present this review hoping to stimulate interest in using the C. elegans model as a vehicle to advance the understanding and future treatment of obesity. PMID:21556043

  4. Characterization of the effects of methylmercury on Caenorhabditis elegans

    SciTech Connect

    Helmcke, Kirsten J.; Syversen, Tore; Miller, David M.; Aschner, Michael

    2009-10-15

    The rising prevalence of methylmercury (MeHg) in seafood and in the global environment provides an impetus for delineating the mechanism of the toxicity of MeHg. Deleterious effects of MeHg have been widely observed in humans and in other mammals, the most striking of which occur in the nervous system. Here we test the model organism, Caenorhabditis elegans (C. elegans), for MeHg toxicity. The simple, well-defined anatomy of the C. elegans nervous system and its ready visualization with green fluorescent protein (GFP) markers facilitated our study of the effects of methylmercuric chloride (MeHgCl) on neural development. Although MeHgCl was lethal to C. elegans, induced a developmental delay, and decreased pharyngeal pumping, other traits including lifespan, brood size, swimming rate, and nervous system morphology were not obviously perturbed in animals that survived MeHgCl exposure. Despite the limited effects of MeHgCl on C. elegans development and behavior, intracellular mercury (Hg) concentrations ({<=} 3 ng Hg/mg protein) in MeHgCl-treated nematodes approached levels that are highly toxic to mammals. If MeHgCl reaches these concentrations throughout the animal, this finding indicates that C. elegans cells, particularly neurons, may be less sensitive to MeHgCl toxicity than mammalian cells. We propose, therefore, that C. elegans should be a useful model for discovering intrinsic mechanisms that confer resistance to MeHgCl exposure.

  5. Characterization of the effects of methylmercury on Caenorhabditis elegans

    PubMed Central

    Helmcke, Kirsten J.; Syversen, Tore; Miller, David M.; Aschner, Michael

    2009-01-01

    The rising prevalence of methylmercury (MeHg) in seafood and in the global environment provides an impetus for delineating the mechanism of the toxicity of MeHg. Deleterious effects of MeHg have been widely observed in humans and in other mammals, the most striking of which occur in the nervous system. Here we test the model organism, Caenorhabditis elegans (C. elegans), for MeHg toxicity. The simple, well-defined anatomy of the C. elegans nervous system and its ready visualization with green fluorescent protein (GFP) markers facilitated our study of the effects of methylmercuric chloride (MeHgCl) on neural development. Although MeHgCl was lethal to C. elegans, induced a developmental delay, and decreased pharyngeal pumping, other traits including lifespan, brood size, swimming rate, and nervous system morphology were not obviously perturbed in animals that survived MeHgCl exposure. Despite the limited effects of MeHgCl on C. elegans development and behavior, intracellular mercury (Hg) concentrations (≤ 3 ng Hg/mg protein) in MeHgCl-treated nematodes approached levels that are highly toxic to mammals. If MeHgCl reaches these concentrations throughout the animal, this finding indicates that C. elegans cells, particularly neurons, may be less sensitive to MeHgCl toxicity than mammalian cells. We propose, therefore, that C. elegans should be a useful model for discovering intrinsic mechanisms that confer resistance to MeHgCl exposure. PMID:19341752

  6. Caenorhabditis elegans opens up new insights into circadian clock mechanisms.

    PubMed

    Hasegawa, Kenji; Saigusa, Tetsu; Tamai, Yoichi

    2005-01-01

    The roundworm, Caenorhabditis elegans, is known to carry homologues of clock genes such as per (=period) and tim (=timeless), which constitute the core of the circadian clock in Drosophila and mammals: lin-42 and tim-1. Analyses using WormBase (C. elegans gene database) have identified with relatively high identity analogous of the clock genes recognized in Drosophila and mammals, with the notable exception of cry (=cryptochrome), which is lacking in C. elegans. All of these C. elegans cognates of the clock genes appear to belong to members of the PAS-superfamily and to participate in development or responsiveness to the environment but apparently are not involved in the C. elegans circadian clock. Nevertheless, C. elegans exhibits convincing circadian rhythms in locomotor behavior in the adult stage and in resistance to hyperosmotic stress in starved larvae (L1) after hatching, indicating that it has a circadian clock with a core design entirely different from that of Drosophila and mammals. Here two possibilities are considered. First, the core of the C. elegans circadian clock includes transcriptional/translational feedback loops between genes and their protein products that are entirely different from those of Drosophila and mammals. Second, a more basic principle such as homeostasis governs the circadian cellular physiology, and was established primarily to minimize the accumulation of DNA damage in response to an environment cycling at 24 h intervals. PMID:15865318

  7. Caenorhabditis elegans as a model for intracellular pathogen infection

    PubMed Central

    Balla, Keir M.; Troemel, Emily R.

    2014-01-01

    Summary The genetically tractable nematode Caenorhabditis elegans is a convenient host for studies of pathogen infection. With the recent identification of two types of natural intracellular pathogens of C. elegans, this host now provides the opportunity to examine interactions and defence against intracellular pathogens in a whole-animal model for infection. C. elegans is the natural host for a genus of microsporidia, which comprise a phylum of fungal-related pathogens of widespread importance for agriculture and medicine. More recently, C. elegans has been shown to be a natural host for viruses related to the Nodaviridae family. Both microsporidian and viral pathogens infect the C. elegans intestine, which is composed of cells that share striking similarities to human intestinal epithelial cells. Because C. elegans nematodes are transparent, these infections provide a unique opportunity to visualize differentiated intestinal cells in vivo during the course of intracellular infection. Together, these two natural pathogens of C. elegans provide powerful systems in which to study microbial pathogenesis and host responses to intracellular infection. PMID:23617769

  8. Solanapyrone analogues from a Hawaiian fungicolous fungus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four new solanayrone analogues (solanapyrones J-M; 1-4) have been isolated from an unidentified fungicolous fungus collected in Hawaii. The structures and relative configurations of these compounds were determined by analysis of ID NMR, 2D NMR, and MS data. Solanapyrone J(1) showed antifungal acti...

  9. Microsporidia Are Natural Intracellular Parasites of the Nematode Caenorhabditis elegans

    PubMed Central

    Troemel, Emily R; Félix, Marie-Anne; Whiteman, Noah K; Barrière, Antoine; Ausubel, Frederick M

    2008-01-01

    For decades the soil nematode Caenorhabditis elegans has been an important model system for biology, but little is known about its natural ecology. Recently, C. elegans has become the focus of studies of innate immunity and several pathogens have been shown to cause lethal intestinal infections in C. elegans. However none of these pathogens has been shown to invade nematode intestinal cells, and no pathogen has been isolated from wild-caught C. elegans. Here we describe an intracellular pathogen isolated from wild-caught C. elegans that we show is a new species of microsporidia. Microsporidia comprise a large class of eukaryotic intracellular parasites that are medically and agriculturally important, but poorly understood. We show that microsporidian infection of the C. elegans intestine proceeds through distinct stages and is transmitted horizontally. Disruption of a conserved cytoskeletal structure in the intestine called the terminal web correlates with the release of microsporidian spores from infected cells, and appears to be part of a novel mechanism by which intracellular pathogens exit from infected cells. Unlike in bacterial intestinal infections, the p38 MAPK and insulin/insulin-like growth factor (IGF) signaling pathways do not appear to play substantial roles in resistance to microsporidian infection in C. elegans. We found microsporidia in multiple wild-caught isolates of Caenorhabditis nematodes from diverse geographic locations. These results indicate that microsporidia are common parasites of C. elegans in the wild. In addition, the interaction between C. elegans and its natural microsporidian parasites provides a system in which to dissect intracellular intestinal infection in vivo and insight into the diversity of pathogenic mechanisms used by intracellular microbes. PMID:19071962

  10. Cellular Symmetry Breaking during Caenorhabditis elegans Development

    PubMed Central

    Munro, Edwin; Bowerman, Bruce

    2009-01-01

    The nematode worm Caenorhabditis elegans has produced a wellspring of insights into mechanisms that govern cellular symmetry breaking during animal development. Here we focus on two highly conserved systems that underlie many of the key symmetry-breaking events that occur during embryonic and larval development in the worm. One involves the interplay between Par proteins, Rho GTPases, and the actomyosin cytoskeleton and mediates asymmetric cell divisions that establish the germline. The other uses elements of the Wnt signaling pathway and a highly reiterative mechanism that distinguishes anterior from posterior daughter cell fates. Much of what we know about these systems comes from intensive study of a few key events—Par/Rho/actomyosin-mediated polarization of the zygote in response to a sperm-derived cue and the Wnt-mediated induction of endoderm at the four-cell stage. However, a growing body of work is revealing how C. elegans exploits elements/variants of these systems to accomplish a diversity of symmetry-breaking tasks throughout embryonic and larval development. PMID:20066102

  11. Macrorestriction Analysis of Caenorhabditis Elegans Genomic DNA

    PubMed Central

    Browning, H.; Berkowitz, L.; Madej, C.; Paulsen, J. E.; Zolan, M. E.; Strome, S.

    1996-01-01

    The usefulness of genomic physical maps is greatly enhanced by linkage of the physical map with the genetic map. We describe a ``macrorestriction mapping'' procedure for Caenorhabditis elegans that we have applied to this endeavor. High molecular weight, genomic DNA is digested with infrequently cutting restriction enzymes and size-fractionated by pulsed field gel electrophoresis. Southern blots of the gels are probed with clones from the C. elegans physical map. This procedure allows the construction of restriction maps covering several hundred kilobases and the detection of polymorphic restriction fragments using probes that map several hundred kilobases away. We describe several applications of this technique. (1) We determined that the amount of DNA in a previously uncloned region is <220 kb. (2) We mapped the mes-1 gene to a cosmid, by detecting polymorphic restriction fragments associated with a deletion allele of the gene. The 25-kb deletion was initially detected using as a probe sequences located ~400 kb away from the gene. (3) We mapped the molecular endpoint of the deficiency hDf6, and determined that three spontaneously derived duplications in the unc-38-dpy-5 region have very complex molecular structures, containing internal rearrangements and deletions. PMID:8889524

  12. Visualizing Neuroblast Cytokinesis During C. elegans Embryogenesis

    PubMed Central

    Wernike, Denise; van Oostende, Chloe; Piekny, Alisa

    2014-01-01

    This protocol describes the use of fluorescence microscopy to image dividing cells within developing Caenorhabditis elegans embryos. In particular, this protocol focuses on how to image dividing neuroblasts, which are found underneath the epidermal cells and may be important for epidermal morphogenesis. Tissue formation is crucial for metazoan development and relies on external cues from neighboring tissues. C. elegans is an excellent model organism to study tissue morphogenesis in vivo due to its transparency and simple organization, making its tissues easy to study via microscopy. Ventral enclosure is the process where the ventral surface of the embryo is covered by a single layer of epithelial cells. This event is thought to be facilitated by the underlying neuroblasts, which provide chemical guidance cues to mediate migration of the overlying epithelial cells. However, the neuroblasts are highly proliferative and also may act as a mechanical substrate for the ventral epidermal cells. Studies using this experimental protocol could uncover the importance of intercellular communication during tissue formation, and could be used to reveal the roles of genes involved in cell division within developing tissues. PMID:24686748

  13. Widespread Genomic Incompatibilities in Caenorhabditis elegans

    PubMed Central

    Snoek, L. Basten; Orbidans, Helen E.; Stastna, Jana J.; Aartse, Aafke; Rodriguez, Miriam; Riksen, Joost A.G.; Kammenga, Jan E.; Harvey, Simon C.

    2014-01-01

    In the Bateson-Dobzhansky-Muller (BDM) model of speciation, incompatibilities emerge from the deleterious interactions between alleles that are neutral or advantageous in the original genetic backgrounds, i.e., negative epistatic effects. Within species such interactions are responsible for outbreeding depression and F2 (hybrid) breakdown. We sought to identify BDM incompatibilities in the nematode Caenorhabditis elegans by looking for genomic regions that disrupt egg laying; a complex, highly regulated, and coordinated phenotype. Investigation of introgression lines and recombinant inbred lines derived from the isolates CB4856 and N2 uncovered multiple incompatibility quantitative trait loci (QTL). These QTL produce a synthetic egg-laying defective phenotype not seen in CB4856 and N2 nor in other wild isolates. For two of the QTL regions, results are inconsistent with a model of pairwise interaction between two loci, suggesting that the incompatibilities are a consequence of complex interactions between multiple loci. Analysis of additional life history traits indicates that the QTL regions identified in these screens are associated with effects on other traits such as lifespan and reproduction, suggesting that the incompatibilities are likely to be deleterious. Taken together, these results indicate that numerous BDM incompatibilities that could contribute to reproductive isolation can be detected and mapped within C. elegans. PMID:25128438

  14. Alcohol Disinhibition of Behaviors in C. elegans

    PubMed Central

    Topper, Stephen M.; Aguilar, Sara C.; Topper, Viktoria Y.; Elbel, Erin; Pierce-Shimomura, Jonathan T.

    2014-01-01

    Alcohol has a wide variety of effects on physiology and behavior. One of the most well-recognized behavioral effects is disinhibition, where behaviors that are normally suppressed are displayed following intoxication. A large body of evidence has shown that alcohol-induced disinhibition in humans affects attention, verbal, sexual, and locomotor behaviors. Similar behavioral disinhibition is also seen in many animal models of ethanol response, from invertebrates to mammals and primates. Here we describe several examples of disinhibition in the nematode C. elegans. The nematode displays distinct behavioral states associated with locomotion (crawling on land and swimming in water) that are mediated by dopamine. On land, animals crawl and feed freely, but these behaviors are inhibited in water. We found that additional behaviors, including a variety of escape responses are also inhibited in water. Whereas alcohol non-specifically impaired locomotion, feeding, and escape responses in worms on land, alcohol specifically disinhibited these behaviors in worms immersed in water. Loss of dopamine signaling relieved disinhibition of feeding behavior, while loss of the D1-like dopamine receptor DOP-4 impaired the ethanol-induced disinhibition of crawling. The powerful genetics and simple nervous system of C. elegans may help uncover conserved molecular mechanisms that underlie alcohol-induced disinhibition of behaviors in higher animals. PMID:24681782

  15. CRISPR-Cas9-guided Genome Engineering in C. elegans

    PubMed Central

    Kim, Hyun-Min; Colaiácovo, Monica P.

    2016-01-01

    The CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) system is successfully being used for efficient and targeted genome editing in various organisms including the nematode C. elegans. Recent studies developed various CRISPR-Cas9 approaches to enhance genome engineering via two major DNA double-strand break repair pathways: non-homologous end joining and homologous recombination. Here we describe a protocol for Cas9-mediated C. elegans genome editing together with single guide RNA (sgRNA) and repair template cloning and injection methods required for delivering Cas9, sgRNAs and repair template DNA into the C. elegans germline. PMID:27366893

  16. The genetics of synapse formation and function in Caenorhabditis elegans.

    PubMed

    Seifert, Mark; Schmidt, Enrico; Baumeister, Ralf

    2006-11-01

    The aim of this review is to introduce the reader to Caenorhabditis elegans as a model system, especially with respect to studies of synapse formation and function. We begin by giving a short description of the structure of the nervous system of C. elegans. As most of the findings that are reviewed here have emerged from studies of neuromuscular junctions (NMJs), two prominent NMJs of C. elegans will be outlined briefly. In addition, we summarize new findings that have added to our understanding of NMJs during the last few years. PMID:16896949

  17. High-resolution imaging of cellular processes in Caenorhabditis elegans.

    PubMed

    Maddox, Amy S; Maddox, Paul S

    2012-01-01

    Differential interference contrast (DIC) imaging of Caenorhabditis elegans embryogenesis led to a Nobel Prize in Physiology or Medicine (Sulston et al., 1983) as did the first use of green fluorescent protein (GFP) in a transgenic C. elegans (Chalfie et al., 1994). Given that C. elegans is free living, does not require exceptional environmental control, and is optically clear, live imaging is a powerful tool in for this model system. Combining genetics with high-resolution imaging has continued to make important contributions to many fields. In this chapter, we discuss how certain aspects of high-resolution microscopy are implemented. This is not an exhaustive review of microscopy; it is meant to be a helpful guide and point of reference for some basic concepts in imaging. While these concepts are largely true for all biological imaging, they are chosen as particularly important for C. elegans. PMID:22226519

  18. Bacterial attraction and quorum sensing inhibition in Caenorhabditis elegans exudates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caenorhabditis elegans, a bacterivorous soil nematode, lives in a complex environment that requires chemical communication for mating, monitoring population density, recognition of food, avoidance of pathogenic microbes, and other essential ecological functions. Despite being one of the best-studied...

  19. Caenorhabditis elegans: An Emerging Model in Biomedical and Environmental Toxicology

    PubMed Central

    Leung, Maxwell C. K.; Williams, Phillip L.; Benedetto, Alexandre; Au, Catherine; Helmcke, Kirsten J.; Aschner, Michael; Meyer, Joel N.

    2008-01-01

    The nematode Caenorhabditis elegans has emerged as an important animal model in various fields including neurobiology, developmental biology, and genetics. Characteristics of this animal model that have contributed to its success include its genetic manipulability, invariant and fully described developmental program, well-characterized genome, ease of maintenance, short and prolific life cycle, and small body size. These same features have led to an increasing use of C. elegans in toxicology, both for mechanistic studies and high-throughput screening approaches. We describe some of the research that has been carried out in the areas of neurotoxicology, genetic toxicology, and environmental toxicology, as well as high-throughput experiments with C. elegans including genome-wide screening for molecular targets of toxicity and rapid toxicity assessment for new chemicals. We argue for an increased role for C. elegans in complementing other model systems in toxicological research. PMID:18566021

  20. Sensory systems: their impact on C. elegans survival

    PubMed Central

    Zhang, Yun; Alcedo, Joy

    2014-01-01

    Summary An animal’s survival strongly depends on a nervous system that can rapidly process and integrate the changing quality of its environment and promote the most appropriate physiological responses. This is amply demonstrated in the nematode worm Caenorhabditis elegans, where its sensory system has been shown to impact multiple physiological traits that range from behavior and developmental plasticity to longevity. Because of the accessibility of its nervous system and the number of tools available to study and manipulate its neural circuitry, C. elegans has thus become an important model organism in dissecting the mechanisms through which the nervous system promotes survival. Here we review our current understanding of how the C. elegans sensory system affects diverse physiological traits, whose coordination would be essential for survival under fluctuating environments. The knowledge we derive from the C. elegans studies should provide testable hypotheses in discovering similar mechanisms in higher animals. PMID:24997267

  1. Caenorhabditis elegans, a Model Organism for Investigating Immunity

    PubMed Central

    Marsh, Elizabeth K.

    2012-01-01

    The nematode Caenorhabditis elegans has been a powerful experimental organism for almost half a century. Over the past 10 years, researchers have begun to exploit the power of C. elegans to investigate the biology of a number of human pathogens. This work has uncovered mechanisms of host immunity and pathogen virulence that are analogous to those involved during pathogenesis in humans or other animal hosts, as well as novel immunity mechanisms which appear to be unique to the worm. More recently, these investigations have uncovered details of the natural pathogens of C. elegans, including the description of a novel intracellular microsporidian parasite as well as new nodaviruses, the first identification of viral infections of this nematode. In this review, we consider the application of C. elegans to human infectious disease research, as well as consider the nematode response to these natural pathogens. PMID:22286994

  2. Genomic response of the nematode Caenorhabditis elegans to spaceflight

    NASA Astrophysics Data System (ADS)

    Selch, Florian; Higashibata, Akira; Imamizo-Sato, Mari; Higashitani, Atsushi; Ishioka, Noriaki; Szewczyk, Nathaniel J.; Conley, Catharine A.

    On Earth, it is common to employ laboratory animals such as the nematode Caenorhabditis elegans to help understand human health concerns. Similar studies in Earth orbit should help understand and address the concerns associated with spaceflight. The “International Caenorhabditis elegans Experiment FIRST” (ICE FIRST), was carried out onboard the Dutch Taxiflight in April of 2004 by an international collaboration of laboratories in France, Canada, Japan and the United States. With the exception of a slight movement defect upon return to Earth, the result of altered muscle development, no significant abnormalities were detected in spaceflown C. elegans. Work from Japan revealed apoptosis proceeds normally and work from Canada revealed no significant increase in the rate of mutation. These results suggest that C. elegans can be used to study non-lethal responses to spaceflight and can possibly be developed as a biological sensor. To further our understanding of C. elegans response to spaceflight, we examined the gene transcription response to the 10 days in space using a near full genome microarray analysis. The transcriptional response is consistent with the observed normal developmental timing, apoptosis, DNA repair, and altered muscle development. The genes identified as altered in response to spaceflight are enriched for genes known to be regulated, in C. elegans, in response to altered environmental conditions (Insulin and TGF-β regulated). These results demonstrate C. elegans can be used to study the effects of altered gravity and suggest that C. elegans responds to spaceflight by altering the expression of at least some of the same metabolic genes that are altered in response to differing terrestrial environments.

  3. The Geometry of Locomotive Behavioral States in C. elegans

    PubMed Central

    Bjorness, Theresa; Greene, Robert; You, Young-Jai

    2013-01-01

    We develop a new hidden Markov model-based method to analyze C elegans locomotive behavior and use this method to quantitatively characterize behavioral states. In agreement with previous work, we find states corresponding to roaming, dwelling, and quiescence. However, we also find evidence for a continuum of intermediate states. We suggest that roaming, dwelling, and quiescence may best be thought of as extremes which, mixed in any proportion, define the locomotive repertoire of C elegans foraging and feeding behavior. PMID:23555813

  4. Imaging Lipid Metabolism in Live Caenorhabditis elegans Using Fingerprint Vibrations**

    PubMed Central

    Wang, Ping; Liu, Bin; Zhang, Delong; Belew, Micah Y.; Cheng, Ji-Xin

    2015-01-01

    Quantitation of lipid storage, desaturation, and oxidation in live C. elegans has been a long-standing obstacle. By hyperspectral stimulated Raman scattering imaging and multivariate analysis in fingerprint vibration region, we present a platform that allows quantitative mapping of fat distribution, degree of fat unsaturation, lipid oxidation, and cholesterol storage in vivo in whole worm. Our results reveal for the first time that lysosome related organelles in intestinal cells are sites for storage of cholesterol in C. elegans. PMID:25195517

  5. Japanese studies on neural circuits and behavior of Caenorhabditis elegans

    PubMed Central

    Sasakura, Hiroyuki; Tsukada, Yuki; Takagi, Shin; Mori, Ikue

    2013-01-01

    The nematode Caenorhabditis elegans is an ideal organism for studying neural plasticity and animal behaviors. A total of 302 neurons of a C. elegans hermaphrodite have been classified into 118 neuronal groups. This simple neural circuit provides a solid basis for understanding the mechanisms of the brains of higher animals, including humans. Recent studies that employ modern imaging and manipulation techniques enable researchers to study the dynamic properties of nervous systems with great precision. Behavioral and molecular genetic analyses of this tiny animal have contributed greatly to the advancement of neural circuit research. Here, we will review the recent studies on the neural circuits of C. elegans that have been conducted in Japan. Several laboratories have established unique and clever methods to study the underlying neuronal substrates of behavioral regulation in C. elegans. The technological advances applied to studies of C. elegans have allowed new approaches for the studies of complex neural systems. Through reviewing the studies on the neuronal circuits of C. elegans in Japan, we will analyze and discuss the directions of neural circuit studies. PMID:24348340

  6. A Transparent Window into Biology: A Primer on Caenorhabditis elegans

    PubMed Central

    Corsi, Ann K.; Wightman, Bruce; Chalfie, Martin

    2015-01-01

    A little over 50 years ago, Sydney Brenner had the foresight to develop the nematode (round worm) Caenorhabditis elegans as a genetic model for understanding questions of developmental biology and neurobiology. Over time, research on C. elegans has expanded to explore a wealth of diverse areas in modern biology including studies of the basic functions and interactions of eukaryotic cells, host–parasite interactions, and evolution. C. elegans has also become an important organism in which to study processes that go awry in human diseases. This primer introduces the organism and the many features that make it an outstanding experimental system, including its small size, rapid life cycle, transparency, and well-annotated genome. We survey the basic anatomical features, common technical approaches, and important discoveries in C. elegans research. Key to studying C. elegans has been the ability to address biological problems genetically, using both forward and reverse genetics, both at the level of the entire organism and at the level of the single, identified cell. These possibilities make C. elegans useful not only in research laboratories, but also in the classroom where it can be used to excite students who actually can see what is happening inside live cells and tissues. PMID:26088431

  7. Caenorhabditis elegans responses to bacteria from its natural habitats

    PubMed Central

    Rowedder, Holli; Braendle, Christian; Félix, Marie-Anne; Ruvkun, Gary

    2016-01-01

    Most Caenorhabditis elegans studies have used laboratory Escherichia coli as diet and microbial environment. Here we characterize bacteria of C. elegans' natural habitats of rotting fruits and vegetation to provide greater context for its physiological responses. By the use of 16S ribosomal DNA (rDNA)-based sequencing, we identified a large variety of bacteria in C. elegans habitats, with phyla Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria being most abundant. From laboratory assays using isolated natural bacteria, C. elegans is able to forage on most bacteria (robust growth on ∼80% of >550 isolates), although ∼20% also impaired growth and arrested and/or stressed animals. Bacterial community composition can predict wild C. elegans population states in both rotting apples and reconstructed microbiomes: alpha-Proteobacteria-rich communities promote proliferation, whereas Bacteroidetes or pathogens correlate with nonproliferating dauers. Combinatorial mixtures of detrimental and beneficial bacteria indicate that bacterial influence is not simply nutritional. Together, these studies provide a foundation for interrogating how bacteria naturally influence C. elegans physiology. PMID:27317746

  8. Caenorhabditis elegans responses to bacteria from its natural habitats.

    PubMed

    Samuel, Buck S; Rowedder, Holli; Braendle, Christian; Félix, Marie-Anne; Ruvkun, Gary

    2016-07-01

    Most Caenorhabditis elegans studies have used laboratory Escherichia coli as diet and microbial environment. Here we characterize bacteria of C. elegans' natural habitats of rotting fruits and vegetation to provide greater context for its physiological responses. By the use of 16S ribosomal DNA (rDNA)-based sequencing, we identified a large variety of bacteria in C. elegans habitats, with phyla Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria being most abundant. From laboratory assays using isolated natural bacteria, C. elegans is able to forage on most bacteria (robust growth on ∼80% of >550 isolates), although ∼20% also impaired growth and arrested and/or stressed animals. Bacterial community composition can predict wild C. elegans population states in both rotting apples and reconstructed microbiomes: alpha-Proteobacteria-rich communities promote proliferation, whereas Bacteroidetes or pathogens correlate with nonproliferating dauers. Combinatorial mixtures of detrimental and beneficial bacteria indicate that bacterial influence is not simply nutritional. Together, these studies provide a foundation for interrogating how bacteria naturally influence C. elegans physiology. PMID:27317746

  9. Ultrafast endocytosis at Caenorhabditis elegans neuromuscular junctions

    PubMed Central

    Watanabe, Shigeki; Liu, Qiang; Davis, M Wayne; Hollopeter, Gunther; Thomas, Nikita; Jorgensen, Nels B; Jorgensen, Erik M

    2013-01-01

    Synaptic vesicles can be released at extremely high rates, which places an extraordinary demand on the recycling machinery. Previous ultrastructural studies of vesicle recycling were conducted in dissected preparations using an intense stimulation to maximize the probability of release. Here, a single light stimulus was applied to motor neurons in intact Caenorhabditis elegans nematodes expressing channelrhodopsin, and the animals rapidly frozen. We found that docked vesicles fuse along a broad active zone in response to a single stimulus, and are replenished with a time constant of about 2 s. Endocytosis occurs within 50 ms adjacent to the dense projection and after 1 s adjacent to adherens junctions. These studies suggest that synaptic vesicle endocytosis may occur on a millisecond time scale following a single physiological stimulus in the intact nervous system and is unlikely to conform to current models of endocytosis. DOI: http://dx.doi.org/10.7554/eLife.00723.001 PMID:24015355

  10. Flow analysis of C. elegans swimming

    NASA Astrophysics Data System (ADS)

    Montenegro-Johnson, Thomas; Gagnon, David; Arratia, Paulo; Lauga, Eric

    2015-11-01

    Improved understanding of microscopic swimming has the potential to impact numerous biomedical and industrial processes. A crucial means of analyzing these systems is through experimental observation of flow fields, from which it is important to be able to accurately deduce swimmer physics such as power consumption, drag forces, and efficiency. We examine the swimming of the nematode worm C. elegans, a model system for undulatory micro-propulsion. Using experimental data of swimmer geometry and kinematics, we employ the regularized stokeslet boundary element method to simulate the swimming of this worm outside the regime of slender-body theory. Simulated flow fields are then compared with experimentally extracted values confined to the swimmer beat plane, demonstrating good agreement. We finally address the question of how to estimate three-dimensional flow information from two-dimensional measurements.

  11. Mainstreaming Caenorhabditis elegans in experimental evolution

    PubMed Central

    Gray, Jeremy C.; Cutter, Asher D.

    2014-01-01

    Experimental evolution provides a powerful manipulative tool for probing evolutionary process and mechanism. As this approach to hypothesis testing has taken purchase in biology, so too has the number of experimental systems that use it, each with its own unique strengths and weaknesses. The depth of biological knowledge about Caenorhabditis nematodes, combined with their laboratory tractability, positions them well for exploiting experimental evolution in animal systems to understand deep questions in evolution and ecology, as well as in molecular genetics and systems biology. To date, Caenorhabditis elegans and related species have proved themselves in experimental evolution studies of the process of mutation, host–pathogen coevolution, mating system evolution and life-history theory. Yet these organisms are not broadly recognized for their utility for evolution experiments and remain underexploited. Here, we outline this experimental evolution work undertaken so far in Caenorhabditis, detail simple methodological tricks that can be exploited and identify research areas that are ripe for future discovery. PMID:24430852

  12. Quantification of Glutathione in Caenorhabditis elegans

    PubMed Central

    Caito, Samuel W.; Aschner, Michael

    2015-01-01

    Glutathione (GSH) is the most abundant intracellular thiol with diverse functions from redox signaling, xenobiotic detoxification, and apoptosis. The quantification of GSH is an important measure for redox capacity and oxidative stress. This protocol quantifies total GSH from Caenorhabditis elegans, an emerging model organism for toxicology studies. GSH is measured using the 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) cycling method originally created for cell and tissue samples but optimized for whole worm extracts. DTNB reacts with GSH to from a 5′-thio-2-nitrobenzoic acid (TNB) chromophore with maximum absorbance of 412 nm. This method is both rapid and sensitive, making it ideal for studies involving a large number of transgenic nematode strains. PMID:26309452

  13. Chemotaxis of crawling and swimming Caenorhabditis Elegans

    NASA Astrophysics Data System (ADS)

    Patel, Amar; Bilbao, Alejandro; Padmanabhan, Venkat; Khan, Zeina; Armstrong, Andrew; Rumbaugh, Kendra; Vanapalli, Siva; Blawzdziewicz, Jerzy

    2012-11-01

    A soil-dwelling nematode Caenorhabditis Elegans efficiently navigates through complex environments, responding to chemical signals to find food or avoid danger. According to previous studies, the nematode uses both gradual-turn and run-and-tumble strategies to move in the direction of the increasing concentration of chemical attractants. We show that both these chemotaxis strategies can be described using our kinematic model [PLoS ONE, 7: e40121 (2012)] in which harmonic-curvature modes represent elementary nematode movements. In our chemotaxis model, the statistics of mode changes is governed by the time history of the chemoattractant concentration at the position of the nematode head. We present results for both nematodes crawling without transverse slip and for swimming nematodes. This work was supported by NSF grant No. CBET 1059745.

  14. [Report on a fungus parasitizing Entamoeba histolytica].

    PubMed

    Cao, C Q; Feng, Y S

    1989-01-01

    Infection of Entamoeba histolytica with chytridiaceous fungus Sphaerita was observed in some specimens obtained from a farmer and stained with iron-haematoxylin. The fungi were found in 78% of the cysts, mostly immature ones. Within the amoebae this parasite occurred singly, in groups, or in the form of a sporangium. It was located in the cytoplasm, the glycogen mass or the chromatoidal bars. In the same specimen, the parasitic fungus was also found in 18% of E. coli cysts; in 11% of E. nana cysts; while only one of 16 E. hartmanni cysts was parasitized. It is an interesting case of superimposed parasitism so far reported in China as well as a rare case of several species of amoebae being heavily involved with the same in the scientific literature. PMID:2548767

  15. Big Data in Caenorhabditis elegans: quo vadis?

    PubMed Central

    Hutter, Harald; Moerman, Donald

    2015-01-01

    A clear definition of what constitutes “Big Data” is difficult to identify, but we find it most useful to define Big Data as a data collection that is complete. By this criterion, researchers on Caenorhabditis elegans have a long history of collecting Big Data, since the organism was selected with the idea of obtaining a complete biological description and understanding of development. The complete wiring diagram of the nervous system, the complete cell lineage, and the complete genome sequence provide a framework to phrase and test hypotheses. Given this history, it might be surprising that the number of “complete” data sets for this organism is actually rather small—not because of lack of effort, but because most types of biological experiments are not currently amenable to complete large-scale data collection. Many are also not inherently limited, so that it becomes difficult to even define completeness. At present, we only have partial data on mutated genes and their phenotypes, gene expression, and protein–protein interaction—important data for many biological questions. Big Data can point toward unexpected correlations, and these unexpected correlations can lead to novel investigations; however, Big Data cannot establish causation. As a result, there is much excitement about Big Data, but there is also a discussion on just what Big Data contributes to solving a biological problem. Because of its relative simplicity, C. elegans is an ideal test bed to explore this issue and at the same time determine what is necessary to build a multicellular organism from a single cell. PMID:26543198

  16. [Caenorhabditis elegans and neuronal death in mammals].

    PubMed

    Selimi, F; Mariani, J; Martinou, J C

    1997-09-01

    The development of the nervous system implies not only the generation of neurons, but also their death. This neuronal death can occur through several mechanisms, one of them being apoptosis. This type of cell death seems to be also implicated in some neurodegenerative diseases. This study of the nematode Caenorhabditis elegans has led to the discovery of several genes controlling apoptosis in neurons. Two of them, the pro-apoptotic ced3 and the anti-apoptotic ced9, have mammalian homologs. The mammalian homologs to Ced9 form the Bcl-2 family and can be either pro-apoptotic or anti-apoptotic. Some of them, Bcl-x, and Bax have been shown to be involved in neuronal death during development in some pathological situations. The first mammalian homolog of Ced3 to be described was the Interleukin-1b Converting Enzymes (ICE). Since then, many other homologs of the proteases Ced3 and ICE have been discovered constituting the Caspases family. These Cysteinyl Aspartate Specific Proteases are pro-apoptotic in many different systems. Several studies using viral or peptidic inhibitors of the Caspases have demonstrated their role in neuronal death in vitro. In vivo, CPP32, a member of the Caspases family, has been shown to be clearly involved in the development of the nervous system. Finally, the analysis of apoptosis in Caenorhabditis elegans has led to the discovery of two families of genes involved in the cascade of events inducing neuronal death in mammals. Indeed, the Caspases seem to be controlled by the Bcl-2 family, as Ced3 is by Ced9. PMID:9683996

  17. [Melanin complex of the fungus Inonotus obliquus].

    PubMed

    Babitskaia, V G; Shcherba, V V; Ikonnikova, N V

    2000-01-01

    The fungus Inonotus obliquus (Pers.) Pil. synthesised high-molecular-weight phenolic pigments that were assigned to melanins according to their physicochemical properties. It was showed that copper ions (0.008%), pyrocatechol (1.0 mM), and tyrosine (20.0 mM) stimulated the melanogenesis. The production of melanin correlated with the synthesis of o- and p-diphenoloxidases. The fungal melanin had strong antioxidant and genoprotective effects. PMID:10994193

  18. Effects of sterols on the development and aging of caenorhabditis elegans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because Caenorhabditis elegans lacks several components of the de novo sterol biosynthesis pathway, it requires sterols as essential nutrients. Supplemented cholesterol undergoes extensive enzymatic modification in C. elegans to form other sterols of unknown function. Because sterol metabolism in ...

  19. Symbiotic Fungi Produce Laccases Potentially Involved in Phenol Degradation in Fungus Combs of Fungus-Growing Termites in Thailand†

    PubMed Central

    Taprab, Yaovapa; Johjima, Toru; Maeda, Yoshimasa; Moriya, Shigeharu; Trakulnaleamsai, Savitr; Noparatnaraporn, Napavarn; Ohkuma, Moriya; Kudo, Toshiaki

    2005-01-01

    Fungus-growing termites efficiently decompose plant litter through their symbiotic relationship with basidiomycete fungi of the genus Termitomyces. Here, we investigated phenol-oxidizing enzymes in symbiotic fungi and fungus combs (a substrate used to cultivate symbiotic fungi) from termites belonging to the genera Macrotermes, Odontotermes, and Microtermes in Thailand, because these enzymes are potentially involved in the degradation of phenolic compounds during fungus comb aging. Laccase activity was detected in all the fungus combs examined as well as in the culture supernatants of isolated symbiotic fungi. Conversely, no peroxidase activity was detected in any of the fungus combs or the symbiotic fungal cultures. The laccase cDNA fragments were amplified directly from RNA extracted from fungus combs of five termite species and a fungal isolate using degenerate primers targeting conserved copper binding domains of basidiomycete laccases, resulting in a total of 13 putative laccase cDNA sequences being identified. The full-length sequences of the laccase cDNA and the corresponding gene, lcc1-2, were identified from the fungus comb of Macrotermes gilvus and a Termitomyces strain isolated from the same fungus comb, respectively. Partial purification of laccase from the fungus comb showed that the lcc1-2 gene product was a dominant laccase in the fungus comb. These findings indicate that the symbiotic fungus secretes laccase to the fungus comb. In addition to laccase, we report novel genes that showed a significant similarity with fungal laccases, but the gene product lacked laccase activity. Interestingly, these genes were highly expressed in symbiotic fungi of all the termite hosts examined. PMID:16332742

  20. Anthelmintic drugs and nematicides: studies in Caenorhabditis elegans.

    PubMed

    Holden-Dye, Lindy; Walker, Robert J

    2014-01-01

    Parasitic nematodes infect many species of animals throughout the phyla, including humans. Moreover, nematodes that parasitise plants are a global problem for agriculture. As such, these nematodes place a major burden on human health, on livestock production, on the welfare of companion animals and on crop production. In the 21st century there are two major challenges posed by the wide-spread prevalence of parasitic nematodes. First, many anthelmintic drugs are losing their effectiveness because nematode strains with resistance are emerging. Second, serious concerns regarding the environmental impact of the nematicides used for crop protection have prompted legislation to remove them from use, leaving agriculture at increased risk from nematode pests. There is clearly a need for a concerted effort to address these challenges. Over the last few decades the free-living nematode Caenorhabditis elegans has provided the opportunity to use molecular genetic techniques for mode of action studies for anthelmintics and nematicides. These approaches continue to be of considerable value. Less fruitful so far, but nonetheless potentially very useful, has been the direct use of C. elegans for anthelmintic and nematicide discovery programmes. Here we provide an introduction to the use of C. elegans as a 'model' parasitic nematode, briefly review the study of nematode control using C. elegans and highlight approaches that have been of particular value with a view to facilitating wider-use of C. elegans as a platform for anthelmintic and nematicide discovery and development. PMID:25517625

  1. Cranberry Product Decreases Fat Accumulation in Caenorhabditis elegans.

    PubMed

    Sun, Quancai; Yue, Yiren; Shen, Peiyi; Yang, Jeremy J; Park, Yeonhwa

    2016-04-01

    Cranberry phenolic compounds have been linked to many health benefits. A recent report suggested that cranberry bioactives inhibit adipogenesis in 3T3-L1 adipocytes. Thus, we investigated the effects and mechanisms of the cranberry product (CP) on lipid metabolism using the Caenorhabditis elegans (C. elegans) model. CP (0.016% and 0.08%) dose-dependently reduced overall fat accumulation in C. elegans (N2, wild type) by 43% and 74%, respectively, without affecting its pumping rates or locomotive activities. CP decreased fat accumulation in aak-2 (an ortholog of AMP-activated kinase α) and tub-1 (an ortholog of TUBBY) mutants significantly, but only minimal effects were observed in sbp-1 (an ortholog of sterol response element-binding protein-1) and nhr-49 (an ortholog of peroxisome proliferator-activated receptor-α) mutant strains. We further confirmed that CP downregulated sbp-1, cebp, and hosl-1 (an ortholog of hormone-sensitive lipase homolog) expression, while increasing the expression of nhr-49 in wild-type C. elegans. These results suggest that CP could effectively reduce fat accumulation in C. elegans dependent on sbp-1, cebp, and nhr-49, but not aak-2 and tub-1. PMID:26991055

  2. Chemically Defined Medium and Caenorhabditis elegans: A Powerful Approach

    NASA Technical Reports Server (NTRS)

    Szewczyk, N. J.; Kozak, E.; Conley, C. A.

    2003-01-01

    C. elegans has been established as a powerful genetic system. Growth in a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of me in large-scale growth and screening of animals. Here we present our initial results from developing culture systems with CeMM. We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats of using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change defined medium composition. As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  3. LRRK2 modulates vulnerability to mitochondrial dysfunction in C. elegans

    PubMed Central

    Saha, Shamol; Guillily, Maria; Ferree, Andrew; Lanceta, Joel; Chan, Diane; Ghosh, Joy; Hsu, Cindy H.; Segal, Lilach; Raghavan, Kesav; Matsumoto, Kunihiro; Hisamoto, Naoki; Kuwahara, Tomoki; Iwatsubo, Takeshi; Moore, Landon; Goldstein, Lee; Cookson, Mark; Wolozin, Benjamin

    2009-01-01

    Summary Mutations in leucine rich repeat kinase 2 (LRRK2) cause autosomal dominant familial Parkinson’s disease. We generated lines of C. elegans expressing neuronally directed human LRRK2. Expressing human LRRK2 expression increased nematode survival in response to rotenone or paraquat, which are agents that cause mitochondrial dysfunction. Protection by G2019S, R1441C or kinase dead LRRK2 was less than protection by wild type LRRK2. Knockdown of lrk-1, the endogenous orthologue of LRRK2 in C. elegans, reduced survival associated with mitochondrial dysfunction. C. elegans expressing LRRK2 showed rapid loss of dopaminergic markers (DAT∷GFP fluorescence and dopamine levels) beginning in early adulthood. Loss of dopaminergic markers was greater for the G2019S LRRK2 line than for the WT line. Rotenone treatment induced a larger loss of dopamine markers in C. elegans expressing G2019S LRRK2 than in C. elegans expressing WT LRRK2; however loss of dopaminergic markers in the G2019S LRRK2 nematode lines was not statistically different than that in the control line. These data suggest that LRRK2 plays an important role in modulating the response to mitochondrial inhibition, and raises the possibility that mutations in LRRK2 selectively enhance the vulnerability of dopaminergic neurons to a stressor associated with Parkinson’s disease. PMID:19625511

  4. The dynamics of the thermal memory of C. elegans

    NASA Astrophysics Data System (ADS)

    Ryu, William; Palanski, Konstantine; Bartumeus, Frederic; Nemenman, Ilya

    2014-03-01

    C. elegans has the capacity to learn associatively. For example, C. elegans associates temperature with food and performs thermotaxis towards this temperature when placed on a spatial thermal gradient. However, very little is understood how C. elegans acquires this thermal memory. We have developed a novel droplet-based microfluidic assay to measure the dynamics of the thermal memory of C. elegans. Individual animals are placed in an array of microdroplets on a slide, and a linear temperature gradient of 0.5 deg/cm is applied to the array. By measuring the swimming motions of C. elegans in the droplets, we show that they can perform thermotaxis. By calculating an index of this taxis behavior over time, we quantify the worm's thermal memory and measure its dynamics when the animals are exposed to different conditions of feeding and starvation. Over a time scale of hours, we find that the thermal preference of wild-type worms decays and will actually become inverted and that mutations in the insulin signaling pathway perturb the dynamics. This biphasic conditional association can be explained with a reinforcement learning model with independent reinforcement and avoidance pathways with distinct time scales. Human Frontier Science Program.

  5. Function and regulation of TRP family channels in C. elegans

    PubMed Central

    Xiao, Rui; Xu, X. Z. Shawn

    2010-01-01

    Seventeen transient receptor potential (TRP) family proteins are encoded by the C. elegans genome, and they cover all of the seven TRP subfamilies, including TRPC, TRPV, TRPM, TRPN, TRPA, TRPP and TRPML. Classical forward and reverse genetic screens have isolated mutant alleles in every C. elegans trp gene, and their characterizations have revealed novel functions and regulatory mechanisms of TRP channels. For example, the TRPC channels TRP-1 and TRP-2 control nicotine-dependent behavior, while TRP-3, a sperm TRPC channel, is regulated by sperm activation and required for sperm-egg interactions during fertilization. Similar to their vertebrate counterparts, C. elegans TRPs function in sensory physiology. For instance, the TRPV channels OSM-9 and OCR-2 act in chemosensation, osmosensation and touch sensation, the TRPA member TRPA-1 regulates touch sensation, while the TRPN channel TRP-4 mediates proprioception. Some C. elegans TRPM, TRPP and TRPML members exhibit cellular functions similar to their vertebrate homologues and have provided insights into human diseases, including polycystic kidney disease, hypomagnesemia and mucolipidosis type IV. The availability of a complete set of trp gene mutants in conjunction with its facile genetics makes C. elegans a powerful model for studying the function and regulation of TRP family channels in vivo. PMID:19421772

  6. Neural circuits mediate electrosensory behavior in Caenorhabditis elegans.

    PubMed

    Gabel, Christopher V; Gabel, Harrison; Pavlichin, Dmitri; Kao, Albert; Clark, Damon A; Samuel, Aravinthan D T

    2007-07-11

    The nematode Caenorhabditis elegans deliberately crawls toward the negative pole in an electric field. By quantifying the movements of individual worms navigating electric fields, we show that C. elegans prefers to crawl at specific angles to the direction of the electric field in persistent periods of forward movement and that the preferred angle is proportional to field strength. C. elegans reorients itself in response to time-varying electric fields by using sudden turns and reversals, standard reorientation maneuvers that C. elegans uses during other modes of motile behavior. Mutation or laser ablation that disrupts the structure and function of amphid sensory neurons also disrupts electrosensory behavior. By imaging intracellular calcium dynamics among the amphid sensory neurons of immobilized worms, we show that specific amphid sensory neurons are sensitive to the direction and strength of electric fields. We extend our analysis to the motor level by showing that specific interneurons affect the utilization of sudden turns and reversals during electrosensory steering. Thus, electrosensory behavior may be used as a model system for understanding how sensory inputs are transformed into motor outputs by the C. elegans nervous system. PMID:17626220

  7. The Caenorhabditis elegans septin complex is nonpolar

    PubMed Central

    John, Corinne M; Hite, Richard K; Weirich, Christine S; Fitzgerald, Daniel J; Jawhari, Hatim; Faty, Mahamadou; Schläpfer, Dominik; Kroschewski, Ruth; Winkler, Fritz K; Walz, Tom; Barral, Yves; Steinmetz, Michel O

    2007-01-01

    Septins are conserved GTPases that form heteromultimeric complexes and assemble into filaments that play a critical role in cell division and polarity. Results from budding and fission yeast indicate that septin complexes form around a tetrameric core. However, the molecular structure of the core and its influence on the polarity of septin complexes and filaments is poorly defined. The septin complex of the nematode Caenorhabditis elegans is formed entirely by the core septins UNC-59 and UNC-61. We show that UNC-59 and UNC-61 form a dimer of coiled-coil-mediated heterodimers. By electron microscopy, this heterotetramer appears as a linear arrangement of four densities representing the four septin subunits. Fusion of GFP to the N termini of UNC-59 and UNC-61 and subsequent electron microscopic visualization suggests that the sequence of septin subunits is UNC-59/UNC-61/UNC-61/UNC-59. Visualization of GFP extensions fused to the extremity of the C-terminal coiled coils indicates that these extend laterally from the heterotetrameric core. Together, our study establishes that the septin core complex is symmetric, and suggests that septins form nonpolar filaments. PMID:17599066

  8. Functional Genomic Analysis of C. elegans Molting

    PubMed Central

    Frand, Alison R; Russel, Sascha

    2005-01-01

    Although the molting cycle is a hallmark of insects and nematodes, neither the endocrine control of molting via size, stage, and nutritional inputs nor the enzymatic mechanism for synthesis and release of the exoskeleton is well understood. Here, we identify endocrine and enzymatic regulators of molting in C. elegans through a genome-wide RNA-interference screen. Products of the 159 genes discovered include annotated transcription factors, secreted peptides, transmembrane proteins, and extracellular matrix enzymes essential for molting. Fusions between several genes and green fluorescent protein show a pulse of expression before each molt in epithelial cells that synthesize the exoskeleton, indicating that the corresponding proteins are made in the correct time and place to regulate molting. We show further that inactivation of particular genes abrogates expression of the green fluorescent protein reporter genes, revealing regulatory networks that might couple the expression of genes essential for molting to endocrine cues. Many molting genes are conserved in parasitic nematodes responsible for human disease, and thus represent attractive targets for pesticide and pharmaceutical development. PMID:16122351

  9. Developmental genetics of the Caenorhabditis elegans pharynx

    PubMed Central

    Pilon, Marc

    2014-01-01

    The Caenorhabditis elegans pharynx is a rhythmically pumping organ composed initially of 80 cells that, through fusions, amount to 62 cells in the adult worm. During the first 100 min of development, most future pharyngeal cells are born and gather into a double-plate primordium surrounded by a basal lamina. All pharyngeal cells express the transcription factor PHA-4, of which the concentration increases throughout development, triggering a sequential activation of genes with promoters responding differentially to PHA-4 protein levels. The oblong-shaped pharyngeal primordium becomes polarized, many cells taking on wedge shapes with their narrow ends toward the center, hence forming an epithelial cyst. The primordium then elongates, and reorientations of the cells at the anterior and posterior ends form the mouth and pharyngeal-intestinal openings, respectively. The 20 pharyngeal neurons establish complex but reproducible trajectories using ‘fishing line’ and growth cone-driven mechanisms, and the gland cells also similarly develop their processes. The genetics behind many fate decisions and morphogenetic processes are being elucidated, and reveal the pharynx to be a fruitful model for developmental biologists. PMID:25262818

  10. Achieving immortality in the C. elegans germline.

    PubMed

    Smelick, Chris; Ahmed, Shawn

    2005-01-01

    Germline immortality is a topic that has intrigued theoretical biologists interested in aging for over a century. The germ cell lineage can be passed from one generation to the next, indefinitely. In contrast, somatic cells are typically only needed for a single generation and are then discarded. Germ cells may, therefore, harbor rejuvenation mechanisms that enable them to proliferate for eons. Such processes are thought to be either absent from or down-regulated in somatic cells, although cell non-autonomous forms of rejuvenation are formally possible. A thorough description of mechanisms that foster eternal youth in germ cells is lacking. The mysteries of germline immortality are being addressed in the nematode Caenorhabditis elegans by studying mutants that reproduce normally for several generations but eventually become sterile. The mortal germline mutants probably become sterile as a consequence of accumulating various forms of heritable cellular damage. Such mutants are abundant, indicating that several different biochemical pathways are required to rejuvenate the germline. Thus, forward genetics should help to define mechanisms that enable the germline to achieve immortality. PMID:15619471

  11. Chromosome I duplications in Caenorhabditis elegans

    SciTech Connect

    McKim, K.S.; Rose, A.M. )

    1990-01-01

    We have isolated and characterized 76 duplications of chromosome I in the genome of Caenorhabditis elegans. The region studied is the 20 map unit left half of the chromosome. Sixty-two duplications were induced with gamma radiation and 14 arose spontaneously. The latter class was apparently the result of spontaneous breaks within the parental duplication. The majority of duplications behave as if they are free. Three duplications are attached to identifiable sequences from other chromosomes. The duplication breakpoints have been mapped by complementation analysis relative to genes on chromosome I. Nineteen duplication breakpoints and seven deficiency breakpoints divide the left half of the chromosome into 24 regions. We have studied the relationship between duplication size and segregational stability. While size is an important determinant of mitotic stability, it is not the only one. We observed clear exceptions to a size-stability correlation. In addition to size, duplication stability may be influenced by specific sequences or chromosome structure. The majority of the duplications were stable enough to be powerful tools for gene mapping. Therefore the duplications described here will be useful in the genetic characterization of chromosome I and the techniques we have developed can be adapted to other regions of the genome.

  12. The microRNAs of Caenorhabditis elegans

    PubMed Central

    Lim, Lee P.; Lau, Nelson C.; Weinstein, Earl G.; Abdelhakim, Aliaa; Yekta, Soraya; Rhoades, Matthew W.; Burge, Christopher B.; Bartel, David P.

    2003-01-01

    MicroRNAs (miRNAs) are an abundant class of tiny RNAs thought to regulate the expression of protein-coding genes in plants and animals. In the present study, we describe a computational procedure to identify miRNA genes conserved in more than one genome. Applying this program, known as MiRscan, together with molecular identification and validation methods, we have identified most of the miRNA genes in the nematode Caenorhabditis elegans. The total number of validated miRNA genes stands at 88, with no more than 35 genes remaining to be detected or validated. These 88 miRNA genes represent 48 gene families; 46 of these families (comprising 86 of the 88 genes) are conserved in Caenorhabditis briggsae, and 22 families are conserved in humans. More than a third of the worm miRNAs, including newly identified members of the lin-4 and let-7 gene families, are differentially expressed during larval development, suggesting a role for these miRNAs in mediating larval developmental transitions. Most are present at very high steady-state levels—more than 1000 molecules per cell, with some exceeding 50,000 molecules per cell. Our census of the worm miRNAs and their expression patterns helps define this class of noncoding RNAs, lays the groundwork for functional studies, and provides the tools for more comprehensive analyses of miRNA genes in other species. PMID:12672692

  13. Overview of gene structure in C. elegans.

    PubMed

    Spieth, John; Lawson, Daniel; Davis, Paul; Williams, Gary; Howe, Kevin

    2014-01-01

    In the early stage of the C. elegans sequencing project, the ab initio gene prediction program Genefinder was used to find protein-coding genes. Subsequently, protein-coding genes structures have been actively curated by WormBase using evidence from all available data sources. Most coding loci were identified by the Genefinder program, but the process of gene curation results in a continual refinement of the details of gene structure, involving the correction and confirmation of intron splice sites, the addition of alternate splicing forms, the merging and splitting of incorrect predictions, and the creation and extension of 5' and 3' ends. The development of new technologies results in the availability of further data sources, and these are incorporated into the evidence used to support the curated structures. Non-coding genes are more difficult to curate using this methodology, and so the structures for most of these have been imported from the literature or from specialist databases of ncRNA data. This article describes the structure and curation of transcribed regions of genes. PMID:25368915

  14. Caenorhabditis elegans vulval cell fate patterning

    NASA Astrophysics Data System (ADS)

    Félix, Marie-Anne

    2012-08-01

    The spatial patterning of three cell fates in a row of competent cells is exemplified by vulva development in the nematode Caenorhabditis elegans. The intercellular signaling network that underlies fate specification is well understood, yet quantitative aspects remain to be elucidated. Quantitative models of the network allow us to test the effect of parameter variation on the cell fate pattern output. Among the parameter sets that allow us to reach the wild-type pattern, two general developmental patterning mechanisms of the three fates can be found: sequential inductions and morphogen-based induction, the former being more robust to parameter variation. Experimentally, the vulval cell fate pattern is robust to stochastic and environmental challenges, and minor variants can be detected. The exception is the fate of the anterior cell, P3.p, which is sensitive to stochastic variation and spontaneous mutation, and is also evolving the fastest. Other vulval precursor cell fates can be affected by mutation, yet little natural variation can be found, suggesting stabilizing selection. Despite this fate pattern conservation, different Caenorhabditis species respond differently to perturbations of the system. In the quantitative models, different parameter sets can reconstitute their response to perturbation, suggesting that network variation among Caenorhabditis species may be quantitative. Network rewiring likely occurred at longer evolutionary scales.

  15. The Genetics of Feeding in Caenorhabditis Elegans

    PubMed Central

    Avery, L.

    1993-01-01

    The pharynx of Caenorhabditis elegans is a nearly self-contained neuromuscular organ responsible for feeding. To identify genes involved in the development or function of the excitable cells of the pharynx, I screened for worms with visible defects in pharyngeal feeding behavior. Fifty-two mutations identified 35 genes, at least 22 previously unknown. The genes broke down into three broad classes: 2 pha genes, mutations in which caused defects in the shape of the pharynx, 7 phm genes, mutations in which caused defects in the contractile structures of the pharyngeal muscle, and 26 eat genes, mutants in which had abnormal pharyngeal muscle motions, but had normally shaped and normally birefringent pharynxes capable of vigorous contraction. Although the Eat phenotypes were diverse, most resembled those caused by defects in the pharyngeal nervous system. For some of the eat genes there is direct evidence from previous genetic mosaic and pharmacological studies that they do in fact affect nervous system. In eat-5 mutants the motions of the different parts of the pharynx were poorly synchronized. eat-6 and eat-12 mutants failed to relax their pharyngeal muscles properly. These pharyngeal motion defects are most easily explained as resulting from abnormal electrical excitability of the pharyngeal muscle membrane. PMID:8462849

  16. In situ soil remediation: Bacteria or fungi?

    SciTech Connect

    Cutright, T.J.; Lee, S.

    1995-07-01

    Contamination of the environment is not a new problem. For most of recorded history, the unwanted byproducts of industrial and residential processes have been dumped into unlined pits or nearby streams. Although disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions were investigated in conjunction with the bacteria Achromobacter sp. and fungus Cunninghamella echinulata var. elegans.

  17. Mechanisms of innate immunity in C. elegans epidermis

    PubMed Central

    Taffoni, Clara; Pujol, Nathalie

    2015-01-01

    The roundworm C. elegans has been successfully used for more than 50 y as a genetically tractable invertebrate model in diverse biological fields such as neurobiology, development and interactions. C. elegans feeds on bacteria and can be naturally infected by a wide range of microorganisms, including viruses, bacteria and fungi. Most of these pathogens infect C. elegans through its gut, but some have developed ways to infect the epidermis. In this review, we will mainly focus on epidermal innate immunity, in particular the signaling pathways and effectors activated upon wounding and fungal infection that serve to protect the host. We will discuss the parallels that exist between epidermal innate immune responses in nematodes and mammals. PMID:26716073

  18. Metabotropic GABA signalling modulates longevity in C. elegans

    PubMed Central

    Chun, Lei; Gong, Jianke; Yuan, Fengling; Zhang, Bi; Liu, Hongkang; Zheng, Tianlin; Yu, Teng; Xu, X. Z. Shawn; Liu, Jianfeng

    2015-01-01

    The nervous system plays an important but poorly understood role in modulating longevity. GABA, a prominent inhibitory neurotransmitter, is best known to regulate nervous system function and behaviour in diverse organisms. Whether GABA signalling affects aging, however, has not been explored. Here we examined mutants lacking each of the major neurotransmitters in C. elegans, and find that deficiency in GABA signalling extends lifespan. This pro-longevity effect is mediated by the metabotropic GABAB receptor GBB-1, but not ionotropic GABAA receptors. GBB-1 regulates lifespan through G protein-PLCβ signalling, which transmits longevity signals to the transcription factor DAF-16/FOXO, a key regulator of lifespan. Mammalian GABAB receptors can functionally substitute for GBB-1 in lifespan control in C. elegans. Our results uncover a new role of GABA signalling in lifespan regulation in C. elegans, raising the possibility that a similar process may occur in other organisms. PMID:26537867

  19. Microbial pathogenesis and host defense in the nematode C. elegans

    PubMed Central

    Cohen, Lianne B.; Troemel, Emily R.

    2014-01-01

    Epithelial cells line the surfaces of the body, and are on the front lines of defense against microbial infection. Like many other metazoans, the nematode C. elegans lacks known professional immune cells and relies heavily on defense mediated by epithelial cells. New results indicate that epithelial defense in C. elegans can be triggered through detection of pathogen-induced perturbation of core physiology within host cells and through autophagic defense against intracellular and extracellular pathogens. Recent studies have also illuminated a diverse array of pathogenic attack strategies used against C. elegans. These findings are providing insight into the underpinnings of host/pathogen interactions in a simple animal host that can inform studies of infectious diseases in humans. PMID:25461579

  20. CRISPR-Cas9-Guided Genome Engineering in C. elegans.

    PubMed

    Kim, Hyun-Min; Colaiácovo, Monica P

    2016-01-01

    The CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) system is successfully being used for efficient and targeted genome editing in various organisms, including the nematode C. elegans. Recent studies have developed various CRISPR-Cas9 approaches to enhance genome engineering via two major DNA double-strand break repair pathways: non-homologous end joining and homologous recombination. Here we describe a protocol for Cas9-mediated C. elegans genome editing together with single guide RNA (sgRNA) and repair template cloning, as well as injection methods required for delivering Cas9, sgRNAs, and repair template DNA into the C. elegans germline. © 2016 by John Wiley & Sons, Inc. PMID:27366893

  1. Femtosecond laser dissection in C. elegans neural circuits

    NASA Astrophysics Data System (ADS)

    Samuel, Aravinthan D. T.; Chung, Samuel H.; Clark, Damon A.; Gabel, Christopher V.; Chang, Chieh; Murthy, Venkatesh; Mazur, Eric

    2006-02-01

    The nematode C. elegans, a millimeter-long roundworm, is a well-established model organism for studies of neural development and behavior, however physiological methods to manipulate and monitor the activity of its neural network have lagged behind the development of powerful methods in genetics and molecular biology. The small size and transparency of C. elegans make the worm an ideal test-bed for the development of physiological methods derived from optics and microscopy. We present the development and application of a new physiological tool: femtosecond laser dissection, which allows us to selectively ablate segments of individual neural fibers within live C. elegans. Femtosecond laser dissection provides a scalpel with submicrometer resolution, and we discuss its application in studies of neural growth, regenerative growth, and the neural basis of behavior.

  2. Dissection of C. elegans behavioral genetics in 3-D environments

    PubMed Central

    Kwon, Namseop; Hwang, Ara B.; You, Young-Jai; V. Lee, Seung-Jae; Ho Je, Jung

    2015-01-01

    The nematode Caenorhabditis elegans is a widely used model for genetic dissection of animal behaviors. Despite extensive technical advances in imaging methods, it remains challenging to visualize and quantify C. elegans behaviors in three-dimensional (3-D) natural environments. Here we developed an innovative 3-D imaging method that enables quantification of C. elegans behavior in 3-D environments. Furthermore, for the first time, we characterized 3-D-specific behavioral phenotypes of mutant worms that have defects in head movement or mechanosensation. This approach allowed us to reveal previously unknown functions of genes in behavioral regulation. We expect that our 3-D imaging method will facilitate new investigations into genetic basis of animal behaviors in natural 3-D environments. PMID:25955271

  3. Homologous gene targeting in Caenorhabditis elegans by biolistic transformation

    PubMed Central

    Berezikov, Eugene; Bargmann, Cornelia I.; Plasterk, Ronald H. A.

    2004-01-01

    Targeted homologous recombination is a powerful approach for genome manipulation that is widely used for gene alteration and knockouts in mouse and yeast. In Caenorhabditis elegans, several methods of target-selected mutagenesis have been implemented but none of them provides the opportunity of introducing exact predefined changes into the genome. Although anecdotal cases of homologous gene targeting in C.elegans have been reported, no practical technique of gene targeting has been developed so far. In this work we demonstrate that transformation of C.elegans by microparticle bombardment (biolistic transformation) can result in homologous recombination between introduced DNA and the chromosomal locus. We describe a scaled up version of biolistic transformation that can be used as a method for homologous gene targeting in the worm. PMID:14982959

  4. The effects of short-term hypergravity on Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Saldanha, Jenifer N.; Pandey, Santosh; Powell-Coffman, Jo Anne

    2016-08-01

    As we seek to recognize the opportunities of advanced aerospace technologies and spaceflight, it is increasingly important to understand the impacts of hypergravity, defined as gravitational forces greater than those present on the earth's surface. The nematode Caenorhabditis elegans has been established as a powerful model to study the effects of altered gravity regimens and has displayed remarkable resilience to space travel. In this study, we investigate the effects of short-term and defined hypergravity exposure on C. elegans motility, brood size, pharyngeal pumping rates, and lifespan. The results from this study advance our understanding of the effects of shorter durations of exposure to increased gravitational forces on C. elegans, and also contribute to the growing body of literature on the impacts of altered gravity regimens on earth's life forms.

  5. Coordination of behavioral hierarchies during environmental transitions in Caenorhabditis elegans

    PubMed Central

    Vidal-Gadea, Andrés G.; Davis, Scott; Becker, Lindsay; Pierce-Shimomura, Jonathan T.

    2012-01-01

    For animals inhabiting multiple environments, the ability to select appropriate behaviors is crucial as their adaptability is often context dependent. Caenorhabditis elegans uses distinct gaits to move on land and in water. Gait transitions can potentially coordinate behaviors associated with distinct environments. We investigated whether land and water differentially affect the behavioral repertoire of C. elegans. Swimming worms interrupted foraging, feeding, egg-laying and defecation. Exogenous dopamine induced bouts of these land-associated behaviors in water. Our finding that worms do not drink fluid while immersed may explain why higher drug doses are required in water than on land to elicit the same effects. C. elegans is a valid model to study behavioral hierarchies and how environmental pressures alter their balance. PMID:23525841

  6. The nematode C. elegans as a complex viscoelastic fluid.

    PubMed

    Backholm, Matilda; Ryu, William S; Dalnoki-Veress, Kari

    2015-05-01

    The viscoelastic material properties of the model organism C. elegans were probed with a micropipette deflection technique and modelled with the standard linear solid model. Dynamic relaxation measurements were performed on the millimetric nematode to investigate its viscous characteristics in detail. We show that the internal properties of C. elegans can not be fully described by a simple Newtonian fluid. Instead, a power-law fluid model was implemented and shown to be in excellent agreement with experimental results. The nematode exhibits shear thinning properties and its complex fluid characteristics were quantified. The bending-rate dependence of the internal damping coefficient of C. elegans could affect its gait modulation in different external environments. PMID:25957177

  7. Behavioral plasticity in C. elegans: paradigms, circuits, genes.

    PubMed

    Hobert, Oliver

    2003-01-01

    Life in the soil is an intellectual and practical challenge that the nematode Caenorhabditis elegans masters by utilizing 302 neurons. The nervous system assembled by these 302 neurons is capable of executing a variety of behaviors, some of respectable complexity. The simplicity of the nervous system, its thoroughly characterized structure, several sets of well-defined behaviors, and its genetic amenability combined with its isogenic background make C. elegans an attractive model organism to study the genetics of behavior. This review describes several behavioral plasticity paradigms in C. elegans and their underlying neuronal circuits and then goes on to review the forward genetic analysis that has been undertaken to identify genes involved in the execution of these behaviors. Lastly, the review outlines how reverse genetics and genomic approaches can guide the analysis of the role of genes in behavior and why and how they will complement the forward genetic analysis of behavior. PMID:12486705

  8. Association of fungus gnats with oomycetal plant pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dark-winged fungus gnats in the genus Bradysia (Diptera: Sciaridae) are especially abundant in greenhouse plant production. It is thought that adult fungus gnats do not feed in the greenhouse setting; however sciarid larvae are known to feed on microorganisms in the soil, including various Oomycete...

  9. Expanding Distribution of Lethal Amphibian Fungus Batrachochytrium salamandrivorans in Europe.

    PubMed

    Spitzen-van der Sluijs, Annemarieke; Martel, An; Asselberghs, Johan; Bales, Emma K; Beukema, Wouter; Bletz, Molly C; Dalbeck, Lutz; Goverse, Edo; Kerres, Alexander; Kinet, Thierry; Kirst, Kai; Laudelout, Arnaud; Marin da Fonte, Luis F; Nöllert, Andreas; Ohlhoff, Dagmar; Sabino-Pinto, Joana; Schmidt, Benedikt R; Speybroeck, Jeroen; Spikmans, Frank; Steinfartz, Sebastian; Veith, Michael; Vences, Miguel; Wagner, Norman; Pasmans, Frank; Lötters, Stefan

    2016-07-01

    Emerging fungal diseases can drive amphibian species to local extinction. During 2010-2016, we examined 1,921 urodeles in 3 European countries. Presence of the chytrid fungus Batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity. PMID:27070102

  10. Draft Genome Sequence of the Cellulolytic Fungus Chaetomium globosum

    PubMed Central

    Ma, Li-Jun; Grabherr, Manfred; Birren, Bruce W.

    2015-01-01

    Chaetomium globosum is a filamentous fungus typically isolated from cellulosic substrates. This species also causes superficial infections of humans and, more rarely, can cause cerebral infections. Here, we report the genome sequence of C. globosum isolate CBS 148.51, which will facilitate the study and comparative analysis of this fungus. PMID:25720678

  11. Metacridamides A and B from the biocontrol fungus metarhizium acridum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metarhizium acridum, an entomopathogenic fungus, has been commercialized and used successfully for biocontrol of grasshopper pests in Africa and Australia. As part of an effort to catalog the secondary metabolites of this fungus we discovered that its conidia produce two novel 17-membered macrocycl...

  12. Expanding Distribution of Lethal Amphibian Fungus Batrachochytrium salamandrivorans in Europe

    PubMed Central

    Spitzen-van der Sluijs, Annemarieke; Martel, An; Asselberghs, Johan; Bales, Emma K.; Beukema, Wouter; Bletz, Molly C.; Dalbeck, Lutz; Goverse, Edo; Kerres, Alexander; Kinet, Thierry; Kirst, Kai; Laudelout, Arnaud; Marin da Fonte, Luis F.; Nöllert, Andreas; Ohlhoff, Dagmar; Sabino-Pinto, Joana; Schmidt, Benedikt R.; Speybroeck, Jeroen; Spikmans, Frank; Steinfartz, Sebastian; Veith, Michael; Vences, Miguel; Wagner, Norman; Pasmans, Frank

    2016-01-01

    Emerging fungal diseases can drive amphibian species to local extinction. During 2010–2016, we examined 1,921 urodeles in 3 European countries. Presence of the chytrid fungus Batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity. PMID:27070102

  13. Staphylococcal biofilm exopolysaccharide protects against Caenorhabditis elegans immune defenses.

    PubMed

    Begun, Jakob; Gaiani, Jessica M; Rohde, Holger; Mack, Dietrich; Calderwood, Stephen B; Ausubel, Frederick M; Sifri, Costi D

    2007-04-01

    Staphylococcus epidermidis and Staphylococcus aureus are leading causes of hospital-acquired infections that have become increasingly difficult to treat due to the prevalence of antibiotic resistance in these organisms. The ability of staphylococci to produce biofilm is an important virulence mechanism that allows bacteria both to adhere to living and artificial surfaces and to resist host immune factors and antibiotics. Here, we show that the icaADBC locus, which synthesizes the biofilm-associated polysaccharide intercellular adhesin (PIA) in staphylococci, is required for the formation of a lethal S. epidermidis infection in the intestine of the model nematode Caenorhabditis elegans. Susceptibility to S. epidermidis infection is influenced by mutation of the C. elegans PMK-1 p38 mitogen-activated protein (MAP) kinase or DAF-2 insulin-signaling pathways. Loss of PIA production abrogates nematocidal activity and leads to reduced bacterial accumulation in the C. elegans intestine, while overexpression of the icaADBC locus in S. aureus augments virulence towards nematodes. PIA-producing S. epidermidis has a significant survival advantage over ica-deficient S. epidermidis within the intestinal tract of wild-type C. elegans, but not in immunocompromised nematodes harboring a loss-of-function mutation in the p38 MAP kinase pathway gene sek-1. Moreover, sek-1 and pmk-1 mutants are equally sensitive to wild-type and icaADBC-deficient S. epidermidis. These results suggest that biofilm exopolysaccharide enhances virulence by playing an immunoprotective role during colonization of the C. elegans intestine. These studies demonstrate that C. elegans can serve as a simple animal model for studying host-pathogen interactions involving staphylococcal biofilm exopolysaccharide and suggest that the protective activity of biofilm matrix represents an ancient conserved function for resisting predation. PMID:17447841

  14. Staphylococcal Biofilm Exopolysaccharide Protects against Caenorhabditis elegans Immune Defenses

    PubMed Central

    Begun, Jakob; Gaiani, Jessica M; Rohde, Holger; Mack, Dietrich; Calderwood, Stephen B; Ausubel, Frederick M; Sifri, Costi D

    2007-01-01

    Staphylococcus epidermidis and Staphylococcus aureus are leading causes of hospital-acquired infections that have become increasingly difficult to treat due to the prevalence of antibiotic resistance in these organisms. The ability of staphylococci to produce biofilm is an important virulence mechanism that allows bacteria both to adhere to living and artificial surfaces and to resist host immune factors and antibiotics. Here, we show that the icaADBC locus, which synthesizes the biofilm-associated polysaccharide intercellular adhesin (PIA) in staphylococci, is required for the formation of a lethal S. epidermidis infection in the intestine of the model nematode Caenorhabditis elegans. Susceptibility to S. epidermidis infection is influenced by mutation of the C. elegans PMK-1 p38 mitogen-activated protein (MAP) kinase or DAF-2 insulin-signaling pathways. Loss of PIA production abrogates nematocidal activity and leads to reduced bacterial accumulation in the C. elegans intestine, while overexpression of the icaADBC locus in S. aureus augments virulence towards nematodes. PIA-producing S. epidermidis has a significant survival advantage over ica-deficient S. epidermidis within the intestinal tract of wild-type C. elegans, but not in immunocompromised nematodes harboring a loss-of-function mutation in the p38 MAP kinase pathway gene sek-1. Moreover, sek-1 and pmk-1 mutants are equally sensitive to wild-type and icaADBC-deficient S. epidermidis. These results suggest that biofilm exopolysaccharide enhances virulence by playing an immunoprotective role during colonization of the C. elegans intestine. These studies demonstrate that C. elegans can serve as a simple animal model for studying host–pathogen interactions involving staphylococcal biofilm exopolysaccharide and suggest that the protective activity of biofilm matrix represents an ancient conserved function for resisting predation. PMID:17447841

  15. Measuring Food Intake and Nutrient Absorption in Caenorhabditis elegans

    PubMed Central

    Gomez-Amaro, Rafael L.; Valentine, Elizabeth R.; Carretero, Maria; LeBoeuf, Sarah E.; Rangaraju, Sunitha; Broaddus, Caroline D.; Solis, Gregory M.; Williamson, James R.; Petrascheck, Michael

    2015-01-01

    Caenorhabditis elegans has emerged as a powerful model to study the genetics of feeding, food-related behaviors, and metabolism. Despite the many advantages of C. elegans as a model organism, direct measurement of its bacterial food intake remains challenging. Here, we describe two complementary methods that measure the food intake of C. elegans. The first method is a microtiter plate-based bacterial clearing assay that measures food intake by quantifying the change in the optical density of bacteria over time. The second method, termed pulse feeding, measures the absorption of food by tracking de novo protein synthesis using a novel metabolic pulse-labeling strategy. Using the bacterial clearance assay, we compare the bacterial food intake of various C. elegans strains and show that long-lived eat mutants eat substantially more than previous estimates. To demonstrate the applicability of the pulse-feeding assay, we compare the assimilation of food for two C. elegans strains in response to serotonin. We show that serotonin-increased feeding leads to increased protein synthesis in a SER-7-dependent manner, including proteins known to promote aging. Protein content in the food has recently emerged as critical factor in determining how food composition affects aging and health. The pulse-feeding assay, by measuring de novo protein synthesis, represents an ideal method to unequivocally establish how the composition of food dictates protein synthesis. In combination, these two assays provide new and powerful tools for C. elegans research to investigate feeding and how food intake affects the proteome and thus the physiology and health of an organism. PMID:25903497

  16. Assembly of complex plant–fungus networks

    PubMed Central

    Toju, Hirokazu; Guimarães, Paulo R.; Olesen, Jens M.; Thompson, John N.

    2014-01-01

    Species in ecological communities build complex webs of interaction. Although revealing the architecture of these networks is fundamental to understanding ecological and evolutionary dynamics in nature, it has been difficult to characterize the structure of most species-rich ecological systems. By overcoming this limitation through next-generation sequencing technology, we herein uncover the network architecture of below-ground plant–fungus symbioses, which are ubiquitous to terrestrial ecosystems. The examined symbiotic network of a temperate forest in Japan includes 33 plant species and 387 functionally and phylogenetically diverse fungal taxa, and the overall network architecture differs fundamentally from that of other ecological networks. In contrast to results for other ecological networks and theoretical predictions for symbiotic networks, the plant–fungus network shows moderate or relatively low levels of interaction specialization and modularity and an unusual pattern of ‘nested’ network architecture. These results suggest that species-rich ecological networks are more architecturally diverse than previously recognized. PMID:25327887

  17. Bacterial farming by the fungus Morchella crassipes.

    PubMed

    Pion, Martin; Spangenberg, Jorge E; Simon, Anaele; Bindschedler, Saskia; Flury, Coralie; Chatelain, Auriel; Bshary, Redouan; Job, Daniel; Junier, Pilar

    2013-12-22

    The interactions between bacteria and fungi, the main actors of the soil microbiome, remain poorly studied. Here, we show that the saprotrophic and ectomycorrhizal soil fungus Morchella crassipes acts as a bacterial farmer of Pseudomonas putida, which serves as a model soil bacterium. Farming by M. crassipes consists of bacterial dispersal, bacterial rearing with fungal exudates, as well as harvesting and translocation of bacterial carbon. The different phases were confirmed experimentally using cell counting and (13)C probing. Common criteria met by other non-human farming systems are also valid for M. crassipes farming, including habitual planting, cultivation and harvesting. Specific traits include delocalization of food production and consumption and separation of roles in the colony (source versus sink areas), which are also found in human agriculture. Our study evidences a hitherto unknown mutualistic association in which bacteria gain through dispersal and rearing, while the fungus gains through the harvesting of an additional carbon source and increased stress resistance of the mycelium. This type of interaction between fungi and bacteria may play a key role in soils. PMID:24174111

  18. Hazardous waste treatment using fungus enters marketplace

    SciTech Connect

    Illman, D.L.

    1993-07-01

    When the announcement was made eight years ago that a common fungus had been found that could degrade a variety of environmental pollutants, the news stirred interest in the scientific community, the private sector, and the general public. Here was the promise of a new technology that might be effective and economical in treating hazardous waste, especially the most recalcitrant of toxic pollutants. Today, commercialization is beginning amid a mixture of optimism and skepticism. The organism in question is white rot fungus, or Phanerochaete chrysosporium, and it belongs to a family of woodrotting fungi common all over North America. The fungi secrete enzymes that break down lignin in wood to carbon dioxide and water--a process called mineralization. These lignin-degrading enzymes are not very discriminating, however. The white rot fungi have been shown to degrade such materials as DDT, the herbicide (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T), 2,4,6-trinitrotoluene (TNT), pentachlorophenol (PCP), creosote, coal tars, and heavy fuels, in many cases mineralizing these pollutants to a significant extent.

  19. Bacterial farming by the fungus Morchella crassipes

    PubMed Central

    Pion, Martin; Spangenberg, Jorge E.; Simon, Anaele; Bindschedler, Saskia; Flury, Coralie; Chatelain, Auriel; Bshary, Redouan; Job, Daniel; Junier, Pilar

    2013-01-01

    The interactions between bacteria and fungi, the main actors of the soil microbiome, remain poorly studied. Here, we show that the saprotrophic and ectomycorrhizal soil fungus Morchella crassipes acts as a bacterial farmer of Pseudomonas putida, which serves as a model soil bacterium. Farming by M. crassipes consists of bacterial dispersal, bacterial rearing with fungal exudates, as well as harvesting and translocation of bacterial carbon. The different phases were confirmed experimentally using cell counting and 13C probing. Common criteria met by other non-human farming systems are also valid for M. crassipes farming, including habitual planting, cultivation and harvesting. Specific traits include delocalization of food production and consumption and separation of roles in the colony (source versus sink areas), which are also found in human agriculture. Our study evidences a hitherto unknown mutualistic association in which bacteria gain through dispersal and rearing, while the fungus gains through the harvesting of an additional carbon source and increased stress resistance of the mycelium. This type of interaction between fungi and bacteria may play a key role in soils. PMID:24174111

  20. Sperm and Oocyte Communication Mechanisms Controlling C. elegans Fertility

    PubMed Central

    Han, Sung Min; Cottee, Pauline A.; Miller, Michael A.

    2010-01-01

    During sexual reproduction in many species, sperm and oocyte secrete diffusible signaling molecules to help orchestrate the biological symphony of fertilization. In the Caenorhabditis elegans gonad, bidirectional signaling between sperm and oocyte is important for guiding sperm to the fertilization site and inducing oocyte maturation. The molecular mechanisms that regulate sperm guidance and oocyte maturation are being delineated. Unexpectedly, these mechanisms are providing insight into human diseases, such as amyotrophic lateral sclerosis, spinal muscular atrophy, and cancer. Here we review sperm and oocyte communication in C. elegans and discuss relationships to human disorders. PMID:20034089

  1. An integrated theory of ageing in the nematode Caenorhabditis elegans

    PubMed Central

    GEMS, DAVID

    2000-01-01

    Numerous theories of ageing have been proposed, and many have been tested experimentally, particularly using nematode models such as Caenorhabditis elegans. By combining those theories of ageing that remain plausible with recent findings from studies of C. elegans life span mutants, an integrated theory of ageing has been devised. This is formed from 3 interconnected elements: the evolutionary theory of ageing, the oxidative damage theory of ageing, and a nonadaptive programmed ageing theory. This tripartite theory of ageing gives rise to a number of predictions that may be tested experimentally. PMID:11197524

  2. Regulation of the X Chromosomes in Caenorhabditis elegans

    PubMed Central

    Kelly, William G.; Ercan, Sevinc; Lieb, Jason D.

    2014-01-01

    Dosage compensation, which regulates the expression of genes residing on the sex chromosomes, has provided valuable insights into chromatin-based mechanisms of gene regulation. The nematode Caenorhabditis elegans has adopted various strategies to down-regulate and even nearly silence the X chromosomes. This article discusses the different chromatin-based strategies used in somatic tissues and in the germline to modulate gene expression from the C. elegans X chromosomes and compares these strategies to those used by other organisms to cope with similar X-chromosome dosage differences. PMID:24591522

  3. CRISPR-Based Methods for Caenorhabditis elegans Genome Engineering.

    PubMed

    Dickinson, Daniel J; Goldstein, Bob

    2016-03-01

    The advent of genome editing techniques based on the clustered regularly interspersed short palindromic repeats (CRISPR)-Cas9 system has revolutionized research in the biological sciences. CRISPR is quickly becoming an indispensible experimental tool for researchers using genetic model organisms, including the nematode Caenorhabditis elegans. Here, we provide an overview of CRISPR-based strategies for genome editing in C. elegans. We focus on practical considerations for successful genome editing, including a discussion of which strategies are best suited to producing different kinds of targeted genome modifications. PMID:26953268

  4. CRISPR-Based Methods for Caenorhabditis elegans Genome Engineering

    PubMed Central

    Dickinson, Daniel J.; Goldstein, Bob

    2016-01-01

    The advent of genome editing techniques based on the clustered regularly interspersed short palindromic repeats (CRISPR)–Cas9 system has revolutionized research in the biological sciences. CRISPR is quickly becoming an indispensible experimental tool for researchers using genetic model organisms, including the nematode Caenorhabditis elegans. Here, we provide an overview of CRISPR-based strategies for genome editing in C. elegans. We focus on practical considerations for successful genome editing, including a discussion of which strategies are best suited to producing different kinds of targeted genome modifications. PMID:26953268

  5. The temporal scaling of Caenorhabditis elegans ageing

    NASA Astrophysics Data System (ADS)

    Stroustrup, Nicholas; Anthony, Winston E.; Nash, Zachary M.; Gowda, Vivek; Gomez, Adam; López-Moyado, Isaac F.; Apfeld, Javier; Fontana, Walter

    2016-02-01

    The process of ageing makes death increasingly likely, involving a random aspect that produces a wide distribution of lifespan even in homogeneous populations. The study of this stochastic behaviour may link molecular mechanisms to the ageing process that determines lifespan. Here, by collecting high-precision mortality statistics from large populations, we observe that interventions as diverse as changes in diet, temperature, exposure to oxidative stress, and disruption of genes including the heat shock factor hsf-1, the hypoxia-inducible factor hif-1, and the insulin/IGF-1 pathway components daf-2, age-1, and daf-16 all alter lifespan distributions by an apparent stretching or shrinking of time. To produce such temporal scaling, each intervention must alter to the same extent throughout adult life all physiological determinants of the risk of death. Organismic ageing in Caenorhabditis elegans therefore appears to involve aspects of physiology that respond in concert to a diverse set of interventions. In this way, temporal scaling identifies a novel state variable, r(t), that governs the risk of death and whose average decay dynamics involves a single effective rate constant of ageing, kr. Interventions that produce temporal scaling influence lifespan exclusively by altering kr. Such interventions, when applied transiently even in early adulthood, temporarily alter kr with an attendant transient increase or decrease in the rate of change in r and a permanent effect on remaining lifespan. The existence of an organismal ageing dynamics that is invariant across genetic and environmental contexts provides the basis for a new, quantitative framework for evaluating the manner and extent to which specific molecular processes contribute to the aspect of ageing that determines lifespan.

  6. The neuronal genome of Caenorhabditis elegans.

    PubMed

    Hobert, Oliver

    2013-01-01

    The ~100 MB genome of C. elegans codes for ~20,000 protein-coding genes many of which are required for the function of the nervous system, composed of 302 neurons in the adult hermaphrodite and of 383 neurons in the adult male. In addition to housekeeping genes, a differentiated neuron is thought to express many hundreds if not thousands of genes that define its functional properties. These genes code for ion channels, G-protein-coupled receptors, neurotransmitter-synthesizing enzymes, transporters and receptors, neuropeptides and their receptors, cell adhesion molecules, motor proteins, signaling molecules and many others. Collectively such genes have been referred to as "terminal differentiation genes" or "effector genes". The differential expression of distinct combinations of terminal differentiation genes define different neuron types. This paper provides a compendium of more than 2,800 putative terminal differentiation genes. One pervasive theme revealed by the analysis of many gene families is the nematode-specific expansions of many neuron function-related gene families, including, for example, many types of ion channel families, sensory receptors and neurotransmitter receptors. The gene lists provided here can serve multiple purposes. They can serve as quick reference guides for individual gene families or they can be used to mine large datasets (e.g., expression datasets) for genes with likely functions in the nervous system. They also serve as a starting point for future projects. For example, a comprehensive understanding of the regulation of the often complex expression patterns of these genes in the nervous system will eventually explain how nervous systems are built. PMID:24081909

  7. The temporal scaling of Caenorhabditis elegans ageing

    PubMed Central

    Stroustrup, Nicholas; Anthony, Winston E.; Nash, Zachary M.; Gowda, Vivek; Gomez, Adam; López-Moyado, Isaac F.; Apfeld, Javier; Fontana, Walter

    2016-01-01

    The process of ageing makes death increasingly likely, but involves a random aspect that produces a wide distribution of lifespan even in homogeneous populations1,2. The study of this stochastic behaviour may link molecular mechanisms to the ageing process that determines lifespan. Here, by collecting high-precision mortality statistics from large populations, we observe that interventions as diverse as changes in diet, temperature, exposure to oxidative stress, and disruption of genes including the heat shock factor hsf-1, the hypoxia-inducible factor hif-1, and the insulin/IGF-1 pathway components daf-2, age-1, and daf-16 all alter lifespan distributions by an apparent stretching or shrinking of time. To produce such temporal scaling, each intervention must alter to the same extent throughout adult life all physiological determinants of the risk of death. Organismic ageing in Caenorhabditis elegans therefore appears to involve aspects of physiology that respond in concert to a diverse set of interventions. In this way, temporal scaling identifies a novel state variable, r(t), that governs the risk of death and whose average decay dynamics involves a single effective rate constant of ageing, kr. Interventions that produce temporal scaling influence lifespan exclusively by altering kr. Such interventions, when applied transiently even in early adulthood, temporarily alter kr with an attendant transient increase or decrease in the rate of change in r and a permanent effect on remaining lifespan. The existence of an organismal ageing dynamics that is invariant across genetic and environmental contexts provides the basis for a new, quantitative framework for evaluating how and how much specific molecular processes contribute to the aspect of ageing that determines lifespan. PMID:26814965

  8. The C. elegans rab family: identification, classification and toolkit construction.

    PubMed

    Gallegos, Maria E; Balakrishnan, Sanjeev; Chandramouli, Priya; Arora, Shaily; Azameera, Aruna; Babushekar, Anitha; Bargoma, Emilee; Bokhari, Abdulmalik; Chava, Siva Kumari; Das, Pranti; Desai, Meetali; Decena, Darlene; Saramma, Sonia Dev Devadas; Dey, Bodhidipra; Doss, Anna-Louise; Gor, Nilang; Gudiputi, Lakshmi; Guo, Chunyuan; Hande, Sonali; Jensen, Megan; Jones, Samantha; Jones, Norman; Jorgens, Danielle; Karamchedu, Padma; Kamrani, Kambiz; Kolora, Lakshmi Divya; Kristensen, Line; Kwan, Kelly; Lau, Henry; Maharaj, Pranesh; Mander, Navneet; Mangipudi, Kalyani; Menakuru, Himabindu; Mody, Vaishali; Mohanty, Sandeepa; Mukkamala, Sridevi; Mundra, Sheena A; Nagaraju, Sudharani; Narayanaswamy, Rajhalutshimi; Ndungu-Case, Catherine; Noorbakhsh, Mersedeh; Patel, Jigna; Patel, Puja; Pendem, Swetha Vandana; Ponakala, Anusha; Rath, Madhusikta; Robles, Michael C; Rokkam, Deepti; Roth, Caroline; Sasidharan, Preeti; Shah, Sapana; Tandon, Shweta; Suprai, Jagdip; Truong, Tina Quynh Nhu; Uthayaruban, Rubatharshini; Varma, Ajitha; Ved, Urvi; Wang, Zeran; Yu, Zhe

    2012-01-01

    Rab monomeric GTPases regulate specific aspects of vesicle transport in eukaryotes including coat recruitment, uncoating, fission, motility, target selection and fusion. Moreover, individual Rab proteins function at specific sites within the cell, for example the ER, golgi and early endosome. Importantly, the localization and function of individual Rab subfamily members are often conserved underscoring the significant contributions that model organisms such as Caenorhabditis elegans can make towards a better understanding of human disease caused by Rab and vesicle trafficking malfunction. With this in mind, a bioinformatics approach was first taken to identify and classify the complete C. elegans Rab family placing individual Rabs into specific subfamilies based on molecular phylogenetics. For genes that were difficult to classify by sequence similarity alone, we did a comparative analysis of intron position among specific subfamilies from yeast to humans. This two-pronged approach allowed the classification of 30 out of 31 C. elegans Rab proteins identified here including Rab31/Rab50, a likely member of the last eukaryotic common ancestor (LECA). Second, a molecular toolset was created to facilitate research on biological processes that involve Rab proteins. Specifically, we used Gateway-compatible C. elegans ORFeome clones as starting material to create 44 full-length, sequence-verified, dominant-negative (DN) and constitutive active (CA) rab open reading frames (ORFs). Development of this toolset provided independent research projects for students enrolled in a research-based molecular techniques course at California State University, East Bay (CSUEB). PMID:23185324

  9. In vivo analysis of recycling endosomes in Caenorhabditis elegans.

    PubMed

    Shi, Anbing; Grant, Barth D

    2015-01-01

    The microscopic nematode Caenorhabditis elegans (C. elegans) serves as an excellent animal model for studying membrane traffic. This is due in part to its highly advanced genetics and genomics, and a transparent body that allows the visualization of fluorescently tagged molecules in the physiologically relevant context of the intact organism. Notably, C. elegans oocytes, coelomocytes, and intestinal epithelia have been established as facile cellular models to explore nonpolarized and polarized cell membrane trafficking mechanisms. In this chapter, we describe in vivo C. elegans assays, utilizing fluorescent dyes or proteins, to examine the molecular mechanisms that control endocytosis and endocytic recycling. Tissue-specific, steady-state imaging and associated quantitative analysis allow the identification and interpretation of subcellular events in the intact animal. To better understand the kinetic characteristics of recycling tubules that mediate membrane protein recycling, we describe recently developed dynamic-imaging assays in intestinal epithelial cells. Such methods bring new clarity to the system, helping to elucidate the functional roles of recycling mediators. PMID:26360035

  10. Caenorhabditis elegans glia modulate neuronal activity and behavior

    PubMed Central

    Stout Jr., Randy F.; Verkhratsky, Alexei; Parpura, Vladimir

    2014-01-01

    Glial cells of Caenorhabditis elegans can modulate neuronal activity and behavior, which is the focus of this review. Initially, we provide an overview of neuroglial evolution, making a comparison between C. elegans glia and their genealogical counterparts. What follows is a brief discussion on C. elegans glia characteristics in terms of their exact numbers, germ layers origin, their necessity for proper development of sensory organs, and lack of their need for neuronal survival. The more specific roles that various glial cells have on neuron-based activity/behavior are succinctly presented. The cephalic sheath glia are important for development, maintenance and activity of central synapses, whereas the amphid glia seem to set the tone of sensory synapses; these glial cell types are ectoderm-derived. Mesoderm-derived Glial-Like cells in the nerve Ring (GLRs) appear to be a part of the circuit for production of motor movement of the worm anterior. Finally, we discuss tools and approaches utilized in studying C. elegans glia, which are assets available for this animal, making it an appealing model, not only in neurosciences, but in biology in general. PMID:24672428

  11. Identification of an estrogenic hormone receptor in Caenorhabditis elegans

    SciTech Connect

    Mimoto, Ai; Fujii, Madoka; Usami, Makoto; Shimamura, Maki; Hirabayashi, Naoko; Kaneko, Takako; Sasagawa, Noboru; Ishiura, Shoichi

    2007-12-28

    Changes in both behavior and gene expression occur in Caenorhabditis elegans following exposure to sex hormones such as estrogen and progesterone, and to bisphenol A (BPA), an estrogenic endocrine-disrupting compound. However, only one steroid hormone receptor has been identified. Of the 284 known nuclear hormone receptors (NHRs) in C. elegans, we selected nhr-14, nhr-69, and nhr-121 for analysis as potential estrogenic hormone receptors, because they share sequence similarity with the human estrogen receptor. First, the genes were cloned and expressed in Escherichia coli, and then the affinity of each protein for estrogen was determined using a surface plasmon resonance (SPR) biosensor. All three NHRs bound estrogen in a dose-dependent fashion. To evaluate the specificity of the binding, we performed a solution competition assay using an SPR biosensor. According to our results, only NHR-14 was able to interact with estrogen. Therefore, we next examined whether nhr-14 regulates estrogen signaling in vivo. To investigate whether these interactions actually control the response of C. elegans to hormones, we investigated the expression of vitellogenin, an estrogen responsive gene, in an nhr-14 mutant. Semi-quantitative RT-PCR showed that vitellogenin expression was significantly reduced in the mutant. This suggests that NHR-14 is a C. elegans estrogenic hormone receptor and that it controls gene expression in response to estrogen.

  12. Concentration dependent differential activity of signalling molecules in Caenorhabditis elegans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caenorhabditis elegans employs specific glycosides of the dideoxysugar ascarylose (the ‘ascarosides’) for monitoring population density/ dauer formation and finding mates. A synergistic blend of three ascarosides, called ascr#2, ascr#3 and ascr#4 acts as a dauer pheromone at a high concentration na...

  13. Blueberry polyphenols increase lifespan and thermotolerance in Caenorhabditis elegans

    PubMed Central

    Wilson, Mark A; Shukitt-Hale, Barbara; Kalt, Wilhelmina; Ingram, Donald K; Joseph, James A; Wolkow, Catherine A

    2006-01-01

    Summary The beneficial effects of polyphenol compounds in fruits and vegetables are mainly extrapolated from in vitro studies or short-term dietary supplementation studies. Due to cost and duration, relatively little is known about whether dietary polyphenols are beneficial in whole animals, particularly with respect to aging. To address this question, we examined the effects of blueberry polyphenols on lifespan and aging of the nematode, Caenorhabditis elegans, a useful organism for such a study. We report that a complex mixture of blue-berry polyphenols increased lifespan and slowed aging-related declines in C. elegans. We also found that these benefits did not just reflect antioxidant activity in these compounds. For instance, blueberry treatment increased survival during acute heat stress, but was not protective against acute oxidative stress. The blueberry extract consists of three major fractions that all contain antioxidant activity. However, only one fraction, enriched in proanthocyanidin compounds, increased C. elegans lifespan and thermotolerance. To further determine how polyphenols prolonged C. elegans lifespan, we analyzed the genetic requirements for these effects. Prolonged lifespan from this treatment required the presence of a CaMKII pathway that mediates osmotic stress resistance, though not other pathways that affect stress resistance and longevity. In conclusion, polyphenolic compounds in blueberries had robust and reproducible benefits during aging that were separable from antioxidant effects. PMID:16441844

  14. Functional analysis of the aquaporin gene family in Caenorhabditis elegans.

    PubMed

    Huang, Chunyi George; Lamitina, Todd; Agre, Peter; Strange, Kevin

    2007-05-01

    Aquaporin channels facilitate the transport of water, glycerol, and other small solutes across cell membranes. The physiological roles of many aquaporins remain unclear. To better understand aquaporin function, we characterized the aquaporin gene family in the nematode Caenorhabditis elegans. Eight canonical aquaporin-encoding genes (aqp) are present in the worm genome. Expression of aqp-2, aqp-3, aqp-4, aqp-6, or aqp-7 in Xenopus oocytes increased water permeability five- to sevenfold. Glycerol permeability was increased three to sevenfold by expression of aqp-1, aqp-3, or aqp-7. Green fluorescent protein transcriptional and translational reporters demonstrated that aqp genes are expressed in numerous C. elegans cell types, including the intestine, excretory cell, and hypodermis, which play important roles in whole animal osmoregulation. To define the role of C. elegans aquaporins in osmotic homeostasis, we isolated deletion alleles for four aqp genes, aqp-2, aqp-3, aqp-4, and aqp-8, which are expressed in osmoregulatory tissues and mediate water transport. Single, double, triple, and quadruple aqp mutant animals exhibited normal survival, development, growth, fertility, and movement under normal and hypertonic culture conditions. aqp-2;aqp-3;aqp-4;aqp-8 quadruple mutants exhibited a slight defect in recovery from hypotonic stress but survived hypotonic stress as well as wild-type animals. These results suggest that C. elegans aquaporins are not essential for whole animal osmoregulation and/or that deletion of aquaporin genes activates mechanisms that compensate for loss of water channel function. PMID:17229810

  15. Biophysical and biological meanings of healthspan from C. elegans cohort

    SciTech Connect

    Suda, Hitoshi

    2014-09-12

    Highlights: • We focus on a third factor, noise, as well as on genetic and environmental factors. • C. elegans fed a healthy food had an extended healthspan as compared to those fed a conventional diet. • An amplification of ATP noise was clearly evident from around the onset of biodemographic aging. • The extension of timing of noise amplification may contribute to effectively extending the healthspan. • The same mechanism of the mean lifespan extension in C. elegans may be realized in humans. - Abstract: Lifespan among individuals ranges widely in organisms from yeast to mammals, even in an isogenic cohort born in a nearly uniform environment. Needless to say, genetic and environmental factors are essential for aging and lifespan, but in addition, a third factor or the existence of a stochastic element must be reflected in aging and lifespan. An essential point is that lifespan or aging is an unpredictable phenomenon. The present study focuses on elucidating the biophysical and biological meanings of healthspan that latently indwells a stochastic nature. To perform this purpose, the nematode Caenorhabditis elegans served as a model animal. C. elegans fed a healthy food had an extended healthspan as compared to those fed a conventional diet. Then, utilizing this phenomenon, we clarified a mechanism of healthspan extension by measuring the single-worm ATP and estimating the ATP noise (or the variability of the ATP content) among individual worms and by quantitatively analyzing biodemographic data with the lifespan equation that was derived from a fluctuation theory.

  16. Silicon-inducible defenses of Zinnia elegans against Myzus persicae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several examples exist of silicon (Si) amendment inducing plant chemical defenses against plant pathogens, but few studies have focused on Si-induced defenses against phloem-feeding herbivores. The current study examined Si treatment of Zinnia elegans Jacq. cv. Oklahoma White (Compositae) on the pe...

  17. The emergence of stereotyped behaviors in C. elegans

    NASA Astrophysics Data System (ADS)

    Stephens, Greg; Ryu, William; Bialek, William

    2010-03-01

    Many organisms, including humans, engage in stereotyped behaviors and these are often attributed to a deterministic command process within the nervous system. Here we use the locomotor dynamics of the nematode C. elegans to suggest an alternative explanation in which stereotyped behavior emerges due to noise within a non-linear dynamical system. In previous work (PLoS Comp Bio 4, e1000028 (2008)) we found that the body shapes of freely-crawling C. elegans are well-captured by four `eigenworms', two of which encode the phase of a locomotory wave that generates forward and backward motion. We also used this representation to infer a non-linear dynamical model for the phase in which forward and backward crawling emerge as attractors of the deterministic dynamics. Here we show that noise induces reversals between forward and backward crawling and that the predicted reversal rate is in good agreement with experiment, with no adjustable parameters. In this model, reversals follow a stereotyped trajectory for the same reason that Brownian escape over a barrier is dominated by a narrowly defined class of trajectories. Stereotypy becomes even clearer in the dynamics with lower noise levels; the real C. elegans is just outside the regime where the reversal rate follows an Arrhenius dependence on the noise level. We discus the implications of our results for C. elegans and other organisms.

  18. Caenorhabditis elegans pathways that surveil and defend mitochondria

    PubMed Central

    Liu, Ying; Samuel, Buck S.; Breen, Peter C.; Ruvkun, Gary

    2014-01-01

    Mitochondrial function is challenged by toxic byproducts of metabolism as well as by pathogen attack1,2. Caenorhabditis elegans normally responds to mitochondrial dysfunction with activation of mitochondrial repair, drug detoxification, and pathogen-response pathways1–7. From a genome-wide RNAi screen, we identified 45 C. elegans genes that are required to upregulate detoxification, pathogen-response, and mitochondrial repair pathways after inhibition of mitochondrial function by drugs or genetic disruption. Animals defective in ceramide biosynthesis are deficient in mitochondrial surveillance, and addition of particular ceramides can rescue the surveillance defects. Ceramide can also rescue the mitochondrial surveillance defects of other gene inactivations, mapping these gene activities upstream of ceramide. Inhibition of the mevalonate pathway, either by RNAi or statin drugs also disrupts mitochondrial surveillance. Growth of C. elegans with a significant fraction of bacterial species from their natural habitat causes mitochondrial dysfunction. Other bacterial species inhibit C. elegans defense responses to a mitochondrial toxin, revealing bacterial countermeasures to animal defense. PMID:24695221

  19. An Elegant Mind: Learning and Memory in "Caenorhabditis elegans"

    ERIC Educational Resources Information Center

    Ardiel, Evan L.; Rankin, Catharine H.

    2010-01-01

    This article reviews the literature on learning and memory in the soil-dwelling nematode "Caenorhabditis elegans." Paradigms include nonassociative learning, associative learning, and imprinting, as worms have been shown to habituate to mechanical and chemical stimuli, as well as learn the smells, tastes, temperatures, and oxygen levels that…

  20. Mechanotransduction: feeling the squeeze in the C. elegans reproductive system.

    PubMed

    Cram, Erin J

    2015-01-19

    A new study reports that the RhoGAP SPV-1 senses membrane curvature and cell stretch in the Caenorhabditis elegans spermatheca. Without SPV-1, the cells of the spermatheca are hypercontractile, leading to deformation and rapid ejection of the fertilized eggs. The spermatheca may provide a paradigm for understanding how cells detect mechanical stimuli in vivo. PMID:25602308

  1. METABOLISM OF AN INSECT NEUROPEPTIDE BY THE NEMATODE C. ELEGANS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We are interested in neuropeptides in nematodes as leads to new control agents for parasitic nematodes. This includes physiological aspects of neuropeptide action and metabolic regulation of these peptides. The free-living nematode Caenorhabditis elegans, with its mapped genome, offers unique opport...

  2. The C. elegans touch response facilitates escape from predacious fungi.

    PubMed

    Maguire, Sean M; Clark, Christopher M; Nunnari, John; Pirri, Jennifer K; Alkema, Mark J

    2011-08-01

    Predator-prey interactions are vital determinants in the natural selection of behavioral traits. Gentle touch to the anterior half of the body of Caenorhabditis elegans elicits an escape response in which the animal quickly reverses and suppresses exploratory head movements [1, 2]. Here, we investigate the ecological significance of the touch response in predator-prey interactions between C. elegans and predacious fungi that catch nematodes using constricting hyphal rings. We show that the constricting rings of Drechslerella doedycoides catch early larval stages with a diameter similar to the trap opening. There is a delay between the ring entry and ring closure, which allows the animal to withdraw from the trap before being caught. Mutants that fail to suppress head movements in response to touch are caught more efficiently than the wild-type. This demonstrates that the coordination of motor programs allows C. elegans to smoothly retract from a fungal noose and evade capture. Our results suggest that selective pressures imposed by predacious fungi have shaped the evolution of C. elegans escape behavior. PMID:21802299

  3. Blueberry polyphenols increase lifespan and thermotolerance in Caenorhabditis elegans.

    PubMed

    Wilson, Mark A; Shukitt-Hale, Barbara; Kalt, Wilhelmina; Ingram, Donald K; Joseph, James A; Wolkow, Catherine A

    2006-02-01

    The beneficial effects of polyphenol compounds in fruits and vegetables are mainly extrapolated from in vitro studies or short-term dietary supplementation studies. Due to cost and duration, relatively little is known about whether dietary polyphenols are beneficial in whole animals, particularly with respect to aging. To address this question, we examined the effects of blueberry polyphenols on lifespan and aging of the nematode, Caenorhabditis elegans, a useful organism for such a study. We report that a complex mixture of blueberry polyphenols increased lifespan and slowed aging-related declines in C. elegans. We also found that these benefits did not just reflect antioxidant activity in these compounds. For instance, blueberry treatment increased survival during acute heat stress, but was not protective against acute oxidative stress. The blueberry extract consists of three major fractions that all contain antioxidant activity. However, only one fraction, enriched in proanthocyanidin compounds, increased C. elegans lifespan and thermotolerance. To further determine how polyphenols prolonged C. elegans lifespan, we analyzed the genetic requirements for these effects. Prolonged lifespan from this treatment required the presence of a CaMKII pathway that mediates osmotic stress resistance, though not other pathways that affect stress resistance and longevity. In conclusion, polyphenolic compounds in blueberries had robust and reproducible benefits during aging that were separable from antioxidant effects. PMID:16441844

  4. Caenorhabditis elegans glia modulate neuronal activity and behavior.

    PubMed

    Stout, Randy F; Verkhratsky, Alexei; Parpura, Vladimir

    2014-01-01

    Glial cells of Caenorhabditis elegans can modulate neuronal activity and behavior, which is the focus of this review. Initially, we provide an overview of neuroglial evolution, making a comparison between C. elegans glia and their genealogical counterparts. What follows is a brief discussion on C. elegans glia characteristics in terms of their exact numbers, germ layers origin, their necessity for proper development of sensory organs, and lack of their need for neuronal survival. The more specific roles that various glial cells have on neuron-based activity/behavior are succinctly presented. The cephalic sheath glia are important for development, maintenance and activity of central synapses, whereas the amphid glia seem to set the tone of sensory synapses; these glial cell types are ectoderm-derived. Mesoderm-derived Glial-Like cells in the nerve Ring (GLRs) appear to be a part of the circuit for production of motor movement of the worm anterior. Finally, we discuss tools and approaches utilized in studying C. elegans glia, which are assets available for this animal, making it an appealing model, not only in neurosciences, but in biology in general. PMID:24672428

  5. The C. elegans Rab Family: Identification, Classification and Toolkit Construction

    PubMed Central

    Gallegos, Maria E.; Balakrishnan, Sanjeev; Chandramouli, Priya

    2012-01-01

    Rab monomeric GTPases regulate specific aspects of vesicle transport in eukaryotes including coat recruitment, uncoating, fission, motility, target selection and fusion. Moreover, individual Rab proteins function at specific sites within the cell, for example the ER, golgi and early endosome. Importantly, the localization and function of individual Rab subfamily members are often conserved underscoring the significant contributions that model organisms such as Caenorhabditis elegans can make towards a better understanding of human disease caused by Rab and vesicle trafficking malfunction. With this in mind, a bioinformatics approach was first taken to identify and classify the complete C. elegans Rab family placing individual Rabs into specific subfamilies based on molecular phylogenetics. For genes that were difficult to classify by sequence similarity alone, we did a comparative analysis of intron position among specific subfamilies from yeast to humans. This two-pronged approach allowed the classification of 30 out of 31 C. elegans Rab proteins identified here including Rab31/Rab50, a likely member of the last eukaryotic common ancestor (LECA). Second, a molecular toolset was created to facilitate research on biological processes that involve Rab proteins. Specifically, we used Gateway-compatible C. elegans ORFeome clones as starting material to create 44 full-length, sequence-verified, dominant-negative (DN) and constitutive active (CA) rab open reading frames (ORFs). Development of this toolset provided independent research projects for students enrolled in a research-based molecular techniques course at California State University, East Bay (CSUEB). PMID:23185324

  6. Identification of Pseudomonas aeruginosa Phenazines that Kill Caenorhabditis elegans

    PubMed Central

    Cezairliyan, Brent; Vinayavekhin, Nawaporn; Grenfell-Lee, Daniel; Yuen, Grace J.; Saghatelian, Alan; Ausubel, Frederick M.

    2013-01-01

    Pathogenic microbes employ a variety of methods to overcome host defenses, including the production and dispersal of molecules that are toxic to their hosts. Pseudomonas aeruginosa, a Gram-negative bacterium, is a pathogen of a diverse variety of hosts including mammals and the nematode Caenorhabditis elegans. In this study, we identify three small molecules in the phenazine class that are produced by P. aeruginosa strain PA14 that are toxic to C. elegans. We demonstrate that 1-hydroxyphenazine, phenazine-1-carboxylic acid, and pyocyanin are capable of killing nematodes in a matter of hours. 1-hydroxyphenazine is toxic over a wide pH range, whereas the toxicities of phenazine-1-carboxylic acid and pyocyanin are pH-dependent at non-overlapping pH ranges. We found that acidification of the growth medium by PA14 activates the toxicity of phenazine-1-carboxylic acid, which is the primary toxic agent towards C. elegans in our assay. Pyocyanin is not toxic under acidic conditions and 1-hydroxyphenazine is produced at concentrations too low to kill C. elegans. These results suggest a role for phenazine-1-carboxylic acid in mammalian pathogenesis because PA14 mutants deficient in phenazine production have been shown to be defective in pathogenesis in mice. More generally, these data demonstrate how diversity within a class of metabolites could affect bacterial toxicity in different environmental niches. PMID:23300454

  7. Is the Fungus Magnaporthe Losing DNA Methylation?

    PubMed Central

    Ikeda, Ken-ichi; Van Vu, Ba; Kadotani, Naoki; Tanaka, Masaki; Murata, Toshiki; Shiina, Kohta; Chuma, Izumi; Tosa, Yukio; Nakayashiki, Hitoshi

    2013-01-01

    The long terminal repeat retrotransposon, Magnaporthe gypsy-like element (MAGGY), has been shown to be targeted for cytosine methylation in a subset of Magnaporthe oryzae field isolates. Analysis of the F1 progeny from a genetic cross between methylation-proficient (Br48) and methylation-deficient (GFSI1-7-2) isolates revealed that methylation of the MAGGY element was governed by a single dominant gene. Positional cloning followed by gene disruption and complementation experiments revealed that the responsible gene was the DNA methyltransferase, MoDMT1, an ortholog of Neurospora crassa Dim-2. A survey of MAGGY methylation in 60 Magnaporthe field isolates revealed that 42 isolates from rice, common millet, wheat, finger millet, and buffelgrass were methylation proficient while 18 isolates from foxtail millet, green bristlegrass, Japanese panicgrass, torpedo grass, Guinea grass, and crabgrass were methylation deficient. Phenotypic analyses showed that MoDMT1 plays no major role in development and pathogenicity of the fungus. Quantitative polymerase chain reaction analysis showed that the average copy number of genomic MAGGY elements was not significantly different between methylation-deficient and -proficient field isolates even though the levels of MAGGY transcript were generally higher in the former group. MoDMT1 gene sequences in the methylation-deficient isolates suggested that at least three independent mutations were responsible for the loss of MoDMT1 function. Overall, our data suggest that MoDMT1 is not essential for the natural life cycle of the fungus and raise the possibility that the genus Magnaporthe may be losing the mechanism of DNA methylation on the evolutionary time scale. PMID:23979580

  8. SKN-1/Nrf, stress responses, and aging in Caenorhabditis elegans.

    PubMed

    Blackwell, T Keith; Steinbaugh, Michael J; Hourihan, John M; Ewald, Collin Y; Isik, Meltem

    2015-11-01

    The mammalian Nrf/CNC proteins (Nrf1, Nrf2, Nrf3, p45 NF-E2) perform a wide range of cellular protective and maintenance functions. The most thoroughly described of these proteins, Nrf2, is best known as a regulator of antioxidant and xenobiotic defense, but more recently has been implicated in additional functions that include proteostasis and metabolic regulation. In the nematode Caenorhabditis elegans, which offers many advantages for genetic analyses, the Nrf/CNC proteins are represented by their ortholog SKN-1. Although SKN-1 has diverged in aspects of how it binds DNA, it exhibits remarkable functional conservation with Nrf/CNC proteins in other species and regulates many of the same target gene families. C. elegans may therefore have considerable predictive value as a discovery model for understanding how mammalian Nrf/CNC proteins function and are regulated in vivo. Work in C. elegans indicates that SKN-1 regulation is surprisingly complex and is influenced by numerous growth, nutrient, and metabolic signals. SKN-1 is also involved in a wide range of homeostatic functions that extend well beyond the canonical Nrf2 function in responses to acute stress. Importantly, SKN-1 plays a central role in diverse genetic and pharmacologic interventions that promote C. elegans longevity, suggesting that mechanisms regulated by SKN-1 may be of conserved importance in aging. These C. elegans studies predict that mammalian Nrf/CNC protein functions and regulation may be similarly complex and that the proteins and processes that they regulate are likely to have a major influence on mammalian life- and healthspan. PMID:26232625

  9. MicroRNA binding sites in C. elegans 3' UTRs.

    PubMed

    Liu, Chaochun; Rennie, William A; Mallick, Bibekanand; Kanoria, Shaveta; Long, Dang; Wolenc, Adam; Carmack, C Steven; Ding, Ye

    2014-01-01

    MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression. Since the discovery of lin-4, the founding member of the miRNA family, over 360 miRNAs have been identified for Caenorhabditis elegans (C. elegans). Prediction and validation of targets are essential for elucidation of regulatory functions of these miRNAs. For C. elegans, crosslinking immunoprecipitation (CLIP) has been successfully performed for the identification of target mRNA sequences bound by Argonaute protein ALG-1. In addition, reliable annotation of the 3' untranslated regions (3' UTRs) as well as developmental stage-specific expression profiles for both miRNAs and 3' UTR isoforms are available. By utilizing these data, we developed statistical models and bioinformatics tools for both transcriptome-scale and developmental stage-specific predictions of miRNA binding sites in C. elegans 3' UTRs. In performance evaluation via cross validation on the ALG-1 CLIP data, the models were found to offer major improvements over established algorithms for predicting both seed sites and seedless sites. In particular, our top-ranked predictions have a substantially higher true positive rate, suggesting a much higher likelihood of positive experimental validation. A gene ontology analysis of stage-specific predictions suggests that miRNAs are involved in dynamic regulation of biological functions during C. elegans development. In particular, miRNAs preferentially target genes related to development, cell cycle, trafficking, and cell signaling processes. A database for both transcriptome-scale and stage-specific predictions and software for implementing the prediction models are available through the Sfold web server at http://sfold.wadsworth.org. PMID:24827614

  10. Recombinational Landscape and Population Genomics of Caenorhabditis elegans

    PubMed Central

    Rockman, Matthew V.; Kruglyak, Leonid

    2009-01-01

    Recombination rate and linkage disequilibrium, the latter a function of population genomic processes, are the critical parameters for mapping by linkage and association, and their patterns in Caenorhabditis elegans are poorly understood. We performed high-density SNP genotyping on a large panel of recombinant inbred advanced intercross lines (RIAILs) of C. elegans to characterize the landscape of recombination and, on a panel of wild strains, to characterize population genomic patterns. We confirmed that C. elegans autosomes exhibit discrete domains of nearly constant recombination rate, and we show, for the first time, that the pattern holds for the X chromosome as well. The terminal domains of each chromosome, spanning about 7% of the genome, exhibit effectively no recombination. The RIAILs exhibit a 5.3-fold expansion of the genetic map. With median marker spacing of 61 kb, they are a powerful resource for mapping quantitative trait loci in C. elegans. Among 125 wild isolates, we identified only 41 distinct haplotypes. The patterns of genotypic similarity suggest that some presumed wild strains are laboratory contaminants. The Hawaiian strain, CB4856, exhibits genetic isolation from the remainder of the global population, whose members exhibit ample evidence of intercrossing and recombining. The population effective recombination rate, estimated from the pattern of linkage disequilibrium, is correlated with the estimated meiotic recombination rate, but its magnitude implies that the effective rate of outcrossing is extremely low, corroborating reports of selection against recombinant genotypes. Despite the low population, effective recombination rate and extensive linkage disequilibrium among chromosomes, which are techniques that account for background levels of genomic similarity, permit association mapping in wild C. elegans strains. PMID:19283065

  11. A Monoclonal Antibody Toolkit for C. elegans

    PubMed Central

    Hadwiger, Gayla; Dour, Scott; Arur, Swathi; Fox, Paul; Nonet, Michael L.

    2010-01-01

    in whole mount immunocytochemistry, most of these antibodies work on western blots and thus should be of use for biochemical fractionation studies. Conclusions/Significance We have produced a set of monoclonal antibodies to subcellular components of the nematode C. elegans for the research community. These reagents are being made available through the Developmental Studies Hybridoma Bank (DSHB). PMID:20405020

  12. Mucormycosis (Mucor fungus ball) of the maxillary sinus.

    PubMed

    Cho, Hang Sun; Yang, Hoon Shik; Kim, Kyung Soo

    2014-01-01

    A fungus ball is an extramucosal fungal proliferation that completely fills one or more paranasal sinuses and usually occurs as a unilateral infection. It is mainly caused by Aspergillus spp in an immunocompetent host, but some cases of paranasal fungal balls reportedly have been caused by Mucor spp. A Mucor fungus ball is usually found in the maxillary sinus and/or the sphenoid sinus and may be black in color. Patients with mucormycosis, or a Mucor fungal ball infection, usually present with facial pain or headache. On computed tomography, there are no pathognomonic findings that are conclusive for a diagnosis of mucormycosis. In this article we report a case of mucormycosis in a 56-year-old woman and provide a comprehensive review of the literature on the "Mucor fungus ball." To the best of our knowledge, 5 case reports (8 patients) have been published in which the fungus ball was thought to be caused by Mucor spp. PMID:25397383

  13. An insect parasitoid carrying an ochratoxin producing fungus

    NASA Astrophysics Data System (ADS)

    Vega, Fernando E.; Posada, Francisco; Gianfagna, Thomas J.; Chaves, Fabio C.; Peterson, Stephen W.

    2006-06-01

    The insect parasitoid Prorops nasuta has been introduced from Africa to many coffee-producing countries in an attempt to control the coffee berry borer. In this paper, we report on the sequencing of the ITS LSU-rDNA and beta-tubulin loci used to identify a fungus isolated from the cuticle of a P. nasuta that emerged from coffee berries infected with the coffee berry borer. The sequences were compared with deposits in GenBank and the fungus was identified as Aspergillus westerdijkiae. The fungus tested positive for ochratoxin A production, with varying levels depending on the media in which it was grown. These results raise the possibility that an insect parasitoid might be disseminating an ochratoxin-producing fungus in coffee plantations.

  14. Mechanosensory Neuron Aging: Differential Trajectories with Lifespan-Extending Alaskan Berry and Fungal Treatments in Caenorhabditis elegans.

    PubMed

    Scerbak, Courtney; Vayndorf, Elena M; Hernandez, Alicia; McGill, Colin; Taylor, Barbara E

    2016-01-01

    Many nutritional interventions that increase lifespan are also proposed to postpone age-related declines in motor and cognitive function. Potential sources of anti-aging compounds are the plants and fungi that have adapted to extreme environments. We studied the effects of four commonly consumed and culturally relevant Interior Alaska berry and fungus species (bog blueberry, lowbush cranberry, crowberry, and chaga) on the decline in overall health and neuron function and changes in touch receptor neuron morphology associated with aging. We observed increased wild-type Caenorhabditis elegans lifespan and improved markers of healthspan upon treatment with Alaskan blueberry, lowbush cranberry, and chaga extracts. Interestingly, although all three treatments increased lifespan, they differentially affected the development of aberrant morphologies in touch receptor neurons. Blueberry treatments decreased anterior mechanosensory neuron (ALM) aberrations (i.e., extended outgrowths and abnormal cell bodies) while lowbush cranberry treatment increased posterior mechanosensory neuron (PLM) aberrations, namely process branching. Chaga treatment both decreased ALM aberrations (i.e., extended outgrowths) and increased PLM aberrations (i.e., process branching and loops). These results support the large body of knowledge positing that there are multiple cellular strategies and mechanisms for promoting health with age. Importantly, these results also demonstrate that although an accumulation of abnormal neuron morphologies is associated with aging and decreased health, not all of these morphologies are detrimental to neuronal and organismal health. PMID:27486399

  15. Mechanosensory Neuron Aging: Differential Trajectories with Lifespan-Extending Alaskan Berry and Fungal Treatments in Caenorhabditis elegans

    PubMed Central

    Scerbak, Courtney; Vayndorf, Elena M.; Hernandez, Alicia; McGill, Colin; Taylor, Barbara E.

    2016-01-01

    Many nutritional interventions that increase lifespan are also proposed to postpone age-related declines in motor and cognitive function. Potential sources of anti-aging compounds are the plants and fungi that have adapted to extreme environments. We studied the effects of four commonly consumed and culturally relevant Interior Alaska berry and fungus species (bog blueberry, lowbush cranberry, crowberry, and chaga) on the decline in overall health and neuron function and changes in touch receptor neuron morphology associated with aging. We observed increased wild-type Caenorhabditis elegans lifespan and improved markers of healthspan upon treatment with Alaskan blueberry, lowbush cranberry, and chaga extracts. Interestingly, although all three treatments increased lifespan, they differentially affected the development of aberrant morphologies in touch receptor neurons. Blueberry treatments decreased anterior mechanosensory neuron (ALM) aberrations (i.e., extended outgrowths and abnormal cell bodies) while lowbush cranberry treatment increased posterior mechanosensory neuron (PLM) aberrations, namely process branching. Chaga treatment both decreased ALM aberrations (i.e., extended outgrowths) and increased PLM aberrations (i.e., process branching and loops). These results support the large body of knowledge positing that there are multiple cellular strategies and mechanisms for promoting health with age. Importantly, these results also demonstrate that although an accumulation of abnormal neuron morphologies is associated with aging and decreased health, not all of these morphologies are detrimental to neuronal and organismal health. PMID:27486399

  16. Fungus Ball in Concha Bullosa: A Rare Case with Anosmia

    PubMed Central

    Özkırıs, Mahmut; Kapusuz, Zeliha; Seçkın, Selda; Saydam, Levent

    2013-01-01

    Concha bullosa is the pneumatization of the concha and is one of the most common variations of the sinonasal anatomy. The histopathological changes caused by the infections which arise from the impaired aeration of conchal cavity are frequently found. Fungus ball of the nasal cavity is an extremely rare, fungal infection with only three cases reported previously. In this paper, we present the fourth fungus ball case which developed within a concha bullosa and presented with anosmia. PMID:23936708

  17. Gene cloning and functional analysis of a second delta 6-fatty acid desaturase from an arachidonic acid-producing Mortierella fungus.

    PubMed

    Sakuradani, Eiji; Shimizu, Sakayu

    2003-04-01

    We demonstrated that Mortierella alpina 1S-4 has two delta 6-desaturases, which are involved in the desaturation of linoleic acid to gamma-linolenic acid. For one of the two delta 6-desaturases, designated as delta 6I, gene cloning and its heterologous expression in a fungus, Aspergillus oryzae, has previously been reported. In addition, we indicated in this paper that there is an isozyme of the two delta 6-desaturases, designated as delta 6II, in M. alpina 1S-4. The predicted amino acid sequences of the Mortierella delta 6-desaturases were similar to those of ones from other organisms, i.e. borage and Caenorhabditis elegans, and had a cytochrome b5-like domain at the N-terminus, being different from the yeast delta 9-desaturase, which has the corresponding domain at the C-terminus. The full-length delta 6II cDNA was expressed in A. oryzae, resulting in the accumulation of gamma-linolenic acid (which was not detected in the control Aspergillus) up to 37% of the total fatty acids. The analysis of real-time quantitative PCR (RTQ-PCR) showed that the quantity of delta 6I RNA was 2.4-, 9-, and 17-fold higher than that of delta 6II RNA on 2, 3, and 4 days in M. alpina 1S-4, respectively. M. alpina 1S-4 is the first fungus to be confirmed to have two functional delta 6-desaturase genes. PMID:12784608

  18. Biological control of Ascaris suum eggs by Pochonia chlamydosporia fungus.

    PubMed

    Ferreira, Sebastião Rodrigo; de Araújo, Jackson Victor; Braga, Fábio Ribeiro; Araujo, Juliana Milani; Frassy, Luiza Neme; Ferreira, Aloízio Soares

    2011-12-01

    Ascaris suum is a gastrointestinal nematode parasite of swines. The aim of this study was to observe Pochonia chlamydosporia fungus on biological control of A. suum eggs after fungus passage through swines gastrointestinal tract. Eighteen pigs, previously dewormed, were randomly divided into three groups: group 1, treated with the fungus isolate VC4; group 2, treated with the fungus isolate VC1 and group 3 did not receive fungus (control). In the treated groups, each animal received a 9 g single dose of mycelium mass containing P. chlamydosporia (VC1 or VC4). Thereafter, animal fecal samples were collected at the following intervals: 8, 12, 24, 36, 48, 72 and 96 h after treatment beginning and these were poured in Petri dishes containing 2% water-agar culture medium. Then, 1,000 A. suum eggs were poured into each dish and kept in an incubator at 26 °C and in the dark for 30 days. After this period, approximately 100 eggs were removed from each Petri dish and morphologically analyzed under light microscopy following the ovicidal activity parameters. The higher percentage observed for isolated VC4 eggs destruction was 57.5% (36 h) after fungus administration and for isolate VC1 this percentage was 45.8% (24 h and 72 h) (p > 0.01). P. chlamydosporia remained viable after passing through the gastrointestinal tract of swines, maintaining its ability of destroying A. suum eggs. PMID:21796329

  19. Genome-Wide RNAi Screens in C. elegans to Identify Genes Influencing Lifespan and Innate Immunity.

    PubMed

    Sinha, Amit; Rae, Robbie

    2016-01-01

    RNA interference is a rapid, inexpensive, and highly effective tool used to inhibit gene function. In C. elegans, whole genome screens have been used to identify genes involved with numerous traits including aging and innate immunity. RNAi in C. elegans can be carried out via feeding, soaking, or injection. Here we outline protocols used to maintain, grow, and carry out RNAi via feeding in C. elegans and determine whether the inhibited genes are essential for lifespan or innate immunity. PMID:27581293

  20. Propulsion by sinusoidal locomotion: A motion inspired by Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Ulrich, Xialing

    Sinusoidal locomotion is commonly seen in snakes, fish, nematodes, or even the wings of some birds and insects. This doctoral thesis presents the study of sinusoidal locomotion of the nematode C. elegans in experiments and the application of the state-space airloads theory to the theoretical forces of sinusoidal motion. An original MATLAB program has been developed to analyze the video records of C. elegans' movement in different fluids, including Newtonian and non-Newtonian fluids. The experimental and numerical studies of swimming C. elegans has revealed three conclusions. First, though the amplitude and wavelength are varying with time, the motion of swimming C. elegans can still be viewed as sinusoidal locomotion with slips. The average normalized wavelength is a conserved character of the locomotion for both Newtonian and non-Newtonian fluids. Second, fluid viscosity affects the frequency but not the moving speed of C. elegans, while fluid elasticity affects the moving speed but not the frequency. Third, by the resistive force theory, for more elastic fluids the ratio of resistive coefficients becomes smaller. Inspired by the motion of C. elegans and other animals performing sinusoidal motion, we investigated the sinusoidal motion of a thin flexible wing in theory. Given the equation of the motion, we have derived the closed forms of propulsive force, lift and other generalized forces applying on the wing. We also calculated the power required to perform the motion, the power lost due to the shed vortices and the propulsive efficiency. These forces and powers are given as functions of reduced frequency k, dimensionless wavelength z, dimensionless amplitude A/b, and time. Our results show that a positive, time-averaged propulsive force is produced for all k>k0=pi/ z. At k=k0, which implies the moment when the moving speed of the wing is the same as the wave speed of its undulation, the motion reaches a steady state with all forces being zero. If there were no

  1. Unidirectional, electrotactic-response valve for Caenorhabditis elegans in microfluidic devices

    NASA Astrophysics Data System (ADS)

    Carr, John A.; Lycke, Roy; Parashar, Archana; Pandey, Santosh

    2011-04-01

    We report a nematode electrotactic-response valve (NERV) to control the locomotion of Caenorhabditis elegans (C. elegans) in microfluidic devices. This nonmechanical, unidirectional valve is based on creating a confined region of lateral electric field that is switchable and reversible. We observed that C. elegans do not prefer to pass through this region if the field lines are incident to its forward movement. Upon reaching the boundary of the NERV, the incident worms partially penetrate the field region, pull back, and turn around. The NERV is tested on three C. elegans mutants: wild-type (N2), lev-8, and acr-16.

  2. Life Span and Motility Effects of Ethanolic Extracts from Sophora moorcroftiana Seeds on Caenorhabditis elegans

    PubMed Central

    Li, Xin; Han, Junxian; Zhu, Rongyan; Cui, Rongrong; Ma, Xingming; Dong, Kaizhong

    2016-01-01

    Background: Sophora moorcroftiana is an endemic shrub species with a great value in folk medicine in Tibet, China. In this study, relatively little is known about whether S. moorcroftiana is beneficial in animals' nervous system and life span or not. Materials and Methods: To address this question, under survival normal temperature (25°C), S. moorcroftiana seeds were extracted with 95% ethanol, and Caenorhabditis elegans were exposed to three different extract concentrations (100 mg/L, 200 mg/L, and 400 mg/mL) from S. moorcroftiana seeds. Results: The 95% ethanolic extracts from S. moorcroftiana seeds could increase life span and slow aging-related increase in C. elegans and could not obviously influence the motility of C. elegans. Conclusion: Given these results by our experiment for life span and motility with 95% ethanolic extracts from S. moorcroftiana seeds in C. elegans, the question whether S. moorcroftiana acts as an anti-aging substance in vivo arises. SUMMARY The 95% ethanolic extracts from S. moorcroftiana seeds have no effect on the life span in C. elegans when extract concentrations from S. moorcroftiana seeds <400 mg/LThe 400 mg/L 95% ethanolic extracts from S. moorcroftiana seeds could increase life span in C. elegansThe 95% ethanolic extracts from S. moorcroftiana seeds could not obviously influence the motility in C. elegans. Abbreviation used: S. moorcroftiana: Sophora moorcroftiana; C. elegan: Caenorhabditis elegan; E. coli OP50: Escherichia coli OP50; DMSO: Dimethyl sulfoxide. PMID:27279712

  3. Malaria Mosquitoes Attracted by Fatal Fungus

    PubMed Central

    George, Justin; Jenkins, Nina E.; Blanford, Simon; Thomas, Matthew B.; Baker, Thomas C.

    2013-01-01

    Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors. PMID:23658757

  4. Malaria mosquitoes attracted by fatal fungus.

    PubMed

    George, Justin; Jenkins, Nina E; Blanford, Simon; Thomas, Matthew B; Baker, Thomas C

    2013-01-01

    Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors. PMID:23658757

  5. The agricultural pathology of ant fungus gardens

    PubMed Central

    Currie, Cameron R.; Mueller, Ulrich G.; Malloch, David

    1999-01-01

    Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that are only known from attine gardens and that are found in most attine nests. These specialized garden parasites, belonging to the microfungus genus Escovopsis (Ascomycota: anamorphic Hypocreales), are horizontally transmitted between colonies. Consistent with theory of virulence evolution under this mode of pathogen transmission, Escovopsis is highly virulent and has the potential for rapid devastation of ant gardens, leading to colony mortality. The specialized parasite Escovopsis is more prevalent in gardens of the more derived ant lineages than in gardens of the more “primitive” (basal) ant lineages. Because fungal cultivars of derived attine lineages are asexual clones of apparently ancient origin whereas cultivars of primitive ant lineages were domesticated relatively recently from free-living sexual stocks, the increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens. PMID:10393936

  6. Secondary Metabolites from the Fungus Emericella nidulans

    PubMed Central

    Tarawneh, Amer H.; León, Francisco; Radwan, Mohamed M.; Rosa, Luiz H.

    2014-01-01

    A new polyketide derivative koninginin H (1), has been isolated from the fungus Emericella nidulans, together with koninginin E (2), koninginin A (3), trichodermatide B (4), citrantifidiol (5), (4S,5R)-4-hydroxy-5-methylfuran-2-one (6), the glycerol derivatives gingerglycolipid B (7), (2S)-bis[9Z,12Z]-1-O, 2-O-dilinoleoyl-3-O-[α-d-galactopyranosyl-(1″→6′)β-d-galactopyranosyl]glycerol (8), (2S)-bis[9Z,12Z]-1-O, 2-O-dilinoleoyl-3-O-β-d-galactopyranosylglycerol (9), the cerebroside flavuside B (10), and the known sterols β-sitosterol glucoside and ergosta-5,7,22-trien-3-ol. Their structures were established by extensive NMR studies (1H NMR, 13C NMR, DEPT, 1H–1H COSY, HSQC, HMBC) and mass spectrometry. The antibacterial, antimalarial, antifungal and antileishmanial activities of compounds 1-10 were examined and the results indicated that compound 4 showed good antifungal activity against Cryptococcus neoformans with an IC50 value of 4.9 μg /mL. PMID:24273867

  7. The first fossil fungus gardens of Isoptera: oldest evidence of symbiotic termite fungiculture (Miocene, Chad basin).

    PubMed

    Duringer, Philippe; Schuster, Mathieu; Genise, Jorge F; Likius, Andossa; Mackaye, Hassan Taisso; Vignaud, Patrick; Brunet, Michel

    2006-12-01

    Higher termites of the subfamily Macrotermitinae (fungus-growing termites) are known to build fungus gardens where a symbiotic fungus (Termitomyces sp.) is cultivated. The fungus grows on a substrate called fungus comb, a structure built with the termites' own faeces. Here we present the first fossil fungus combs ever found in the world. They were extracted from 7-million-year-old continental sandstone (Chad basin). Fossilized fungus combs have an ovoid morphology with a more or less flattened concave base and a characteristic general alveolar aspect. Under lens, they display a typical millimetre-scale pelletal structure. The latter, as well as the general shape and alveolar aspect, are similar to the morphology of fungus combs from extant fungus-growing termites. PMID:16924476

  8. The first fossil fungus gardens of Isoptera: oldest evidence of symbiotic termite fungiculture (Miocene, Chad basin)

    NASA Astrophysics Data System (ADS)

    Duringer, Philippe; Schuster, Mathieu; Genise, Jorge F.; Likius, Andossa; Mackaye, Hassan Taisso; Vignaud, Patrick; Brunet, Michel

    2006-12-01

    Higher termites of the subfamily Macrotermitinae (fungus-growing termites) are known to build fungus gardens where a symbiotic fungus ( Termitomyces sp.) is cultivated. The fungus grows on a substrate called fungus comb, a structure built with the termites’ own faeces. Here we present the first fossil fungus combs ever found in the world. They were extracted from 7-million-year-old continental sandstone (Chad basin). Fossilized fungus combs have an ovoid morphology with a more or less flattened concave base and a characteristic general alveolar aspect. Under lens, they display a typical millimetre-scale pelletal structure. The latter, as well as the general shape and alveolar aspect, are similar to the morphology of fungus combs from extant fungus-growing termites.

  9. C. elegans epigenetic regulation in development and aging

    PubMed Central

    González-Aguilera, Cristina; Palladino, Francesca

    2014-01-01

    The precise developmental map of the Caenorhabditis elegans cell lineage, as well as a complete genome sequence and feasibility of genetic manipulation make this nematode species highly attractive to study the role of epigenetics during development. Genetic dissection of phenotypical traits, such as formation of egg-laying organs or starvation-resistant dauer larvae, has illustrated how chromatin modifiers may regulate specific cell-fate decisions and behavioral programs. Moreover, the transparent body of C. elegans facilitates non-invasive microscopy to study tissue-specific accumulation of heterochromatin at the nuclear periphery. We also review here recent findings on how small RNA molecules contribute to epigenetic control of gene expression that can be propagated for several generations and eventually determine longevity. PMID:24326118

  10. C. elegans as a model for membrane traffic

    PubMed Central

    Sato, Ken; Norris, Anne; Sato, Miyuki; Grant, Barth D.

    2014-01-01

    The counterbalancing action of the endocytosis and secretory pathways maintains a dynamic equilibrium that regulates the composition of the plasma membrane, allowing it to maintain homeostasis and to change rapidly in response to changes in the extracellular environment and/or intracellular metabolism. These pathways are intimately integrated with intercellular signaling systems and play critical roles in all cells. Studies in Caenorhabditis elegans have revealed diverse roles of membrane trafficking in physiology and development and have also provided molecular insight into the fundamental mechanisms that direct cargo sorting, vesicle budding, and membrane fisson and fusion. In this review, we summarize progress in understanding membrane trafficking mechanisms derived from work in C. elegans, focusing mainly on work done in non-neuronal cell-types, especially the germline, early embryo, coelomocytes, and intestine. PMID:24778088

  11. Transcriptional Regulation of Gene Expression in C. elegans

    PubMed Central

    Reinke, Valerie; Krause, Michael; Okkema, Peter

    2013-01-01

    Protein coding gene sequences are converted to mRNA by the highly regulated process of transcription. The precise temporal and spatial control of transcription for many genes is an essential part of development in metazoans. Thus, understanding the molecular mechanisms underlying transcriptional control is essential to understanding cell fate determination during embryogenesis, post-embryonic development, many environmental interactions, and disease-related processes. Studies of transcriptional regulation in C. elegans exploit its genomic simplicity and physical characteristics to define regulatory events with single cell and minute time scale resolution. When combined with the genetics of the system, C. elegans offers a unique and powerful vantage point from which to study how chromatin-associated protein and their modifications interact with transcription factors and their binding sites to yield precise control of gene expression through transcriptional regulation. PMID:23801596

  12. The genetics of ivermectin resistance in Caenorhabditis elegans.

    PubMed

    Dent, J A; Smith, M M; Vassilatis, D K; Avery, L

    2000-03-14

    The ability of organisms to evolve resistance threatens the effectiveness of every antibiotic drug. We show that in the nematode Caenorhabditis elegans, simultaneous mutation of three genes, avr-14, avr-15, and glc-1, encoding glutamate-gated chloride channel (GluCl) alpha-type subunits confers high-level resistance to the antiparasitic drug ivermectin. In contrast, mutating any two channel genes confers modest or no resistance. We propose a model in which ivermectin sensitivity in C. elegans is mediated by genes affecting parallel genetic pathways defined by the family of GluCl genes. The sensitivity of these pathways is further modulated by unc-7, unc-9, and the Dyf (dye filling defective) genes, which alter the structure of the nervous system. Our results suggest that the evolution of drug resistance can be slowed by targeting antibiotic drugs to several members of a multigene family. PMID:10716995

  13. Meiotic recombination and the crossover assurance checkpoint in Caenorhabditis elegans.

    PubMed

    Yu, Zhouliang; Kim, Yumi; Dernburg, Abby F

    2016-06-01

    During meiotic prophase, chromosomes pair and synapse with their homologs and undergo programmed DNA double-strand break (DSB) formation to initiate meiotic recombination. These DSBs are processed to generate a limited number of crossover recombination products on each chromosome, which are essential to ensure faithful segregation of homologous chromosomes. The nematode Caenorhabditis elegans has served as an excellent model organism to investigate the mechanisms that drive and coordinate these chromosome dynamics during meiosis. Here we focus on our current understanding of the regulation of DSB induction in C. elegans. We also review evidence that feedback regulation of crossover formation prolongs the early stages of meiotic prophase, and discuss evidence that this can alter the recombination pattern, most likely by shifting the genome-wide distribution of DSBs. PMID:27013114

  14. Dietary and microbiome factors determine longevity in Caenorhabditis elegans.

    PubMed

    Sánchez-Blanco, Adolfo; Rodríguez-Matellán, Alberto; González-Paramás, Ana; González-Manzano, Susana; Kim, Stuart K; Mollinedo, Faustino

    2016-07-01

    Diet composition affects organismal health. Nutrient uptake depends on the microbiome. Caenorhabditis elegans fed a Bacillus subtilis diet live longer than those fed the standard Escherichia coli diet. Here we report that this longevity difference is primarily caused by dietary coQ, an antioxidant synthesized by E. coli but not by B. subtilis. CoQ-supplemented E. coli fed worms have a lower oxidation state yet live shorter than coQ-less B. subtilis fed worms. We showed that mutations affecting longevity for E. coli fed worms do not always lead to similar effects when worms are fed B. subtilis. We propose that coQ supplementation by the E. coli diet alters the worm cellular REDOX homeostasis, thus decreasing longevity. Our results highlight the importance of microbiome factors in longevity, argue that antioxidant supplementation can be detrimental, and suggest that the C. elegans standard E. coli diet can alter the effect of signaling pathways on longevity. PMID:27510225

  15. Sensory regulation of C. elegans male mate-searching behaviour

    PubMed Central

    Barrios, Arantza; Nurrish, Stephen; Emmons, Scott W.

    2009-01-01

    Summary How do animals integrate internal drives and external environmental cues to coordinate behaviours? We address this question studying mate-searching behaviour in C. elegans. C. elgans males explore their environment in search of mates (hermaphrodites) and will leave food if mating partners are absent. However, when mates and food coincide, male exploratory behaviour is suppressed and males are retained on the food source. We show that the drive to explore is stimulated by male specific neurons in the tail, the ray neurons. Periodic contact with the hermaphrodite detected through ray neurons changes the male’s behaviour during periods of no contact and prevents the male from leaving the food source. The hermaphrodite signal is conveyed by male-specific interneurons that are post-synaptic to the rays and that send processes to the major integrative center in the head. This study identifies key parts of the neural circuit that regulates a sexual appetitive behaviour in C. elegans. PMID:19062284

  16. Dietary and microbiome factors determine longevity in Caenorhabditis elegans

    PubMed Central

    Sánchez-Blanco, Adolfo; Rodríguez-Matellán, Alberto; González-Paramás, Ana; González-Manzano, Susana; Kim, Stuart K.; Mollinedo, Faustino

    2016-01-01

    Diet composition affects organismal health. Nutrient uptake depends on the microbiome. Caenorhabditis elegans fed a Bacillus subtilis diet live longer than those fed the standard Escherichia coli diet. Here we report that this longevity difference is primarily caused by dietary coQ, an antioxidant synthesized by E. coli but not by B. subtilis. CoQ-supplemented E. coli fed worms have a lower oxidation state yet live shorter than coQ-less B. subtilis fed worms. We showed that mutations affecting longevity for E. coli fed worms do not always lead to similar effects when worms are fed B. subtilis. We propose that coQ supplementation by the E. coli diet alters the worm cellular REDOX homeostasis, thus decreasing longevity. Our results highlight the importance of microbiome factors in longevity, argue that antioxidant supplementation can be detrimental, and suggest that the C. elegans standard E. coli diet can alter the effect of signaling pathways on longevity. PMID:27510225

  17. A microfluidic device for efficient chemical testing using Caenorhabditis elegans.

    PubMed

    Song, Pengfei; Zhang, Weize; Sobolevski, Alexandre; Bernard, Kristine; Hekimi, Siegfried; Liu, Xinyu

    2015-04-01

    The nematode worm Caenorhabditis elegans has been employed as a popular model organism in many fields of biological research. In this paper, we present a microfluidic device for facilitating chemical testing using C. elegans. For testing chemicals on chip, the device houses single nematodes in microfluidic chambers and precisely adjusts the chamber's chemical environment during experiments. Eight nematodes can be readily loaded into the chambers through separate loading channels in a quick and gentle manner. In addition, a custom-made software with a graphic user interface is also created for quantitative analysis of locomotion parameters (swimming frequency and bend amplitude) of the nematodes in response to chemical stimuli, thus greatly enhancing the efficiency of data collection. We perform proof-of-concept experiments using two chemicals, zinc ion (Zn(2+)) and glucose, to demonstrate the effectiveness of the microfluidic device. PMID:25744157

  18. Measuring the effects of high CO₂ levels in Caenorhabditis elegans.

    PubMed

    Zuela, Noam; Friedman, Nurit; Zaslaver, Alon; Gruenbaum, Yosef

    2014-08-01

    Carbon dioxide (CO2) is an important molecule in cell metabolism. It is also a byproduct of many physiological processes. In humans, impaired lung function and lung diseases disrupt the body's ability to dispose of CO2 and elevate its levels in the body (hypercapnia). Animal models allow further understanding of how CO2 is sensed in the body and what are the physiological responses to high CO2 levels. This information can provide new strategies in the battle against the detrimental effects of CO2 accumulation in lung diseases. The nematode Caenorhabditis elegans provides us with such a model animal due to its natural ability to sense and navigate through varying concentrations of CO2, as well as the fact that it can be genetically manipulated with ease. Here we describe the different methods used to measure the effects elevated levels of CO2 have on the molecular sensing mechanism and physiology of C. elegans. PMID:24650565

  19. The C. elegans healthspan and stress-resistance assay toolkit.

    PubMed

    Keith, Scott Alexander; Amrit, Francis Raj Gandhi; Ratnappan, Ramesh; Ghazi, Arjumand

    2014-08-01

    A wealth of knowledge on the genetic mechanisms that govern aging has emerged from the study of mutants that exhibit enhanced longevity and exceptional resilience to adverse environmental conditions. In these studies, lifespan has been an excellent proxy for establishing the rate of aging, but it is not always correlated with qualitative measures of healthy aging or 'healthspan'. Although the attributes of healthspan have been challenging to define, they share some universal features that are increasingly being incorporated into aging studies. Here we describe methods used to determine Caenorhabditis elegans healthspan. These include assessments of tissue integrity and functionality and resistance to a variety of biotic and abiotic stressors. We have chosen to include simple, rapid assays in this collection that can be easily undertaken in any C. elegans laboratory, and can be relied on to provide a preliminary but thorough insight into the healthspan of a population. PMID:24727065

  20. Alteration of Caenorhabditis elegans gene expression by targeted transformation.

    PubMed Central

    Broverman, S; MacMorris, M; Blumenthal, T

    1993-01-01

    We have produced strains carrying a synthetic fusion of parts of two vitellogenin genes, vit-2 and vit-6, integrated into the Caenorhabditis elegans genome. In most of the 63 transformant strains, the plasmid sequences are integrated at random locations in the genome. However, in two strains the transgene integrated by homologous recombination into the endogenous vit-2 gene. In both cases the reciprocal exchange between the chromosome and the injected circular plasmid containing a promoter deletion led to switching of the plasmid-borne promoter and the endogenous promoter, with a reduction in vit-2 expression. Thus in nematodes, transforming DNA can integrate by homologous recombination to result in partial inactivation of the chromosomal locus. The simplicity of the event and its reasonably high frequency suggest that gene targeting by homologous recombination should be considered as a method for directed inactivation of C. elegans genes. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8506273

  1. Alteration of Caenorhabditis elegans gene expression by targeted transformation.

    PubMed

    Broverman, S; MacMorris, M; Blumenthal, T

    1993-05-15

    We have produced strains carrying a synthetic fusion of parts of two vitellogenin genes, vit-2 and vit-6, integrated into the Caenorhabditis elegans genome. In most of the 63 transformant strains, the plasmid sequences are integrated at random locations in the genome. However, in two strains the transgene integrated by homologous recombination into the endogenous vit-2 gene. In both cases the reciprocal exchange between the chromosome and the injected circular plasmid containing a promoter deletion led to switching of the plasmid-borne promoter and the endogenous promoter, with a reduction in vit-2 expression. Thus in nematodes, transforming DNA can integrate by homologous recombination to result in partial inactivation of the chromosomal locus. The simplicity of the event and its reasonably high frequency suggest that gene targeting by homologous recombination should be considered as a method for directed inactivation of C. elegans genes. PMID:8506273

  2. High-throughput imaging of neuronal activity in Caenorhabditis elegans

    PubMed Central

    Larsch, Johannes; Ventimiglia, Donovan; Bargmann, Cornelia I.; Albrecht, Dirk R.

    2013-01-01

    Neuronal responses to sensory inputs can vary based on genotype, development, experience, or stochastic factors. Existing neuronal recording techniques examine a single animal at a time, limiting understanding of the variability and range of potential responses. To scale up neuronal recordings, we here describe a system for simultaneous wide-field imaging of neuronal calcium activity from at least 20 Caenorhabditis elegans animals under precise microfluidic chemical stimulation. This increased experimental throughput was used to perform a systematic characterization of chemosensory neuron responses to multiple odors, odor concentrations, and temporal patterns, as well as responses to pharmacological manipulation. The system allowed recordings from sensory neurons and interneurons in freely moving animals, whose neuronal responses could be correlated with behavior. Wide-field imaging provides a tool for comprehensive circuit analysis with elevated throughput in C. elegans. PMID:24145415

  3. A comparison of tracking methods for swimming C. Elegans

    NASA Astrophysics Data System (ADS)

    Restif, Christophe; Metaxas, Dimitris

    2010-03-01

    Tracking the swimming motion of C. elegans worms is of high interest for a variety of research projects on behavior in biology, from aging to mating studies. We compare six different tracking methods, derived from two types of image preprocessing, namely local and global thresholding methods, and from three types of segmentation methods: low-level vision, and articulated models of either constant or varying width. All these methods have been successfully used in recent related works, with some modifications to adapt them to swimming motions. We show a quantitative comparison of these methods using computer-vision measures. To discuss their relative strengths and weaknesses, we consider three scenarios of behavior studies, depending on the constraints of a C. elegans project, and give suggestions as to which methods are more adapted to each case, and how to further improve them.

  4. Direct measurements of drag forces in C. elegans crawling locomotion.

    PubMed

    Rabets, Yegor; Backholm, Matilda; Dalnoki-Veress, Kari; Ryu, William S

    2014-10-21

    With a simple and versatile microcantilever-based force measurement technique, we have probed the drag forces involved in Caenorhabditis elegans locomotion. As a worm crawls on an agar surface, we found that substrate viscoelasticity introduces nonlinearities in the force-velocity relationships, yielding nonconstant drag coefficients that are not captured by original resistive force theory. A major contributing factor to these nonlinearities is the formation of a shallow groove on the agar surface. We measured both the adhesion forces that cause the worm's body to settle into the agar and the resulting dynamics of groove formation. Furthermore, we quantified the locomotive forces produced by C. elegans undulatory motions on a wet viscoelastic agar surface. We show that an extension of resistive force theory is able to use the dynamics of a nematode's body shape along with the measured drag coefficients to predict the forces generated by a crawling nematode. PMID:25418179

  5. Caenorhabditis elegans as a model for cancer research

    PubMed Central

    Kyriakakis, Emmanouil; Markaki, Maria; Tavernarakis, Nektarios

    2015-01-01

    The term cancer describes a group of multifaceted diseases characterized by an intricate pathophysiology. Despite significant advances in the fight against cancer, it remains a key public health concern and burden on societies worldwide. Elucidation of key molecular and cellular mechanisms of oncogenic diseases will facilitate the development of better intervention strategies to counter or prevent tumor development. In vivo and in vitro models have long been used to delineate distinct biological processes involved in cancer such as apoptosis, proliferation, angiogenesis, invasion, metastasis, genome instability, and metabolism. In this review, we introduce Caenorhabditis elegans as an emerging animal model for systematic dissection of the molecular basis of tumorigenesis, focusing on the well-established processes of apoptosis and autophagy. Additionally, we propose that C. elegans can be used to advance our understanding of cancer progression, such as deregulation of energy metabolism, stem cell reprogramming, and host–microflora interactions. PMID:27308424

  6. Magnetosensitive neurons mediate geomagnetic orientation in Caenorhabditis elegans.

    PubMed

    Vidal-Gadea, Andrés; Ward, Kristi; Beron, Celia; Ghorashian, Navid; Gokce, Sertan; Russell, Joshua; Truong, Nicholas; Parikh, Adhishri; Gadea, Otilia; Ben-Yakar, Adela; Pierce-Shimomura, Jonathan

    2015-01-01

    Many organisms spanning from bacteria to mammals orient to the earth's magnetic field. For a few animals, central neurons responsive to earth-strength magnetic fields have been identified; however, magnetosensory neurons have yet to be identified in any animal. We show that the nematode Caenorhabditis elegans orients to the earth's magnetic field during vertical burrowing migrations. Well-fed worms migrated up, while starved worms migrated down. Populations isolated from around the world, migrated at angles to the magnetic vector that would optimize vertical translation in their native soil, with northern- and southern-hemisphere worms displaying opposite migratory preferences. Magnetic orientation and vertical migrations required the TAX-4 cyclic nucleotide-gated ion channel in the AFD sensory neuron pair. Calcium imaging showed that these neurons respond to magnetic fields even without synaptic input. C. elegans may have adapted magnetic orientation to simplify their vertical burrowing migration by reducing the orientation task from three dimensions to one. PMID:26083711

  7. A recombineering pipeline for functional genomics applied to Caenorhabditis elegans.

    PubMed

    Sarov, Mihail; Schneider, Susan; Pozniakovski, Andrei; Roguev, Assen; Ernst, Susanne; Zhang, Youming; Hyman, A Anthony; Stewart, A Francis

    2006-10-01

    We present a new concept in DNA engineering based on a pipeline of serial recombineering steps in liquid culture. This approach is fast, straightforward and facilitates simultaneous processing of multiple samples in parallel. We validated the approach by generating green fluorescent protein (GFP)-tagged transgenes from Caenorhabditis briggsae genomic clones in a multistep pipeline that takes only 4 d. The transgenes were engineered with minimal disturbance to the natural genomic context so that the correct level and pattern of expression will be secured after transgenesis. An example transgene for the C. briggsae ortholog of lin-59 was used for ballistic transformation in Caenorhabditis elegans. We show that the cross-species transgene is correctly expressed and rescues RNA interference (RNAi)-mediated knockdown of the endogenous C. elegans gene. The strategy that we describe adapts the power of recombineering in Escherichia coli for fluent DNA engineering to a format that can be directly scaled up for genomic projects. PMID:16990816

  8. Granulicatella elegans endocarditis: a diagnostic and therapeutic challenge.

    PubMed

    Patri, Sandeep; Agrawal, Yashwant

    2016-01-01

    A 63-year-old man with a history of non-ischaemic cardiomyopathy presented with acute worsening of heart failure and septic shock. Echocardiogram revealed a large aortic valve vegetation with new onset severe aortic incompetence. Blood cultures grew Granulicatella elegans, for which antimicrobial sensitivities could not be carried out in our lab. Despite antibiotic therapy and aggressive care, the patient's clinical condition worsened and he died. G. elegans, previously grouped under nutrient variant streptococci (NVS), is an extremely rare cause for bacterial infective endocarditis (IE). Unlike with the Viridans group, IE caused by NVS has a very poor outcome and higher mortality rate. The difficulty in isolation of the bacteria in culture, inability to reliably measure antibiotic susceptibility in vitro, frequent treatment failure and complications such as multivalvular involvement, make this an extremely challenging infection to treat. Early detection of the organism, appropriate antibiotics and early surgical management when indicated, are key to management. PMID:26921367

  9. Sensory activity affects sensory axon development in C. elegans.

    PubMed

    Peckol, E L; Zallen, J A; Yarrow, J C; Bargmann, C I

    1999-05-01

    The simple nervous system of the nematode C. elegans consists of 302 neurons with highly reproducible morphologies, suggesting a hard-wired program of axon guidance. Surprisingly, we show here that sensory activity shapes sensory axon morphology in C. elegans. A class of mutants with deformed sensory cilia at their dendrite endings have extra axon branches, suggesting that sensory deprivation disrupts axon outgrowth. Mutations that alter calcium channels or membrane potential cause similar defects. Cell-specific perturbations of sensory activity can cause cell-autonomous changes in axon morphology. Although the sensory axons initially reach their targets in the embryo, the mutations that alter sensory activity cause extra axon growth late in development. Thus, perturbations of activity affect the maintenance of sensory axon morphology after an initial pattern of innervation is established. This system provides a genetically tractable model for identifying molecular mechanisms linking neuronal activity to nervous system structure. PMID:10101123

  10. Aging. Lysosomal signaling molecules regulate longevity in Caenorhabditis elegans.

    PubMed

    Folick, Andrew; Oakley, Holly D; Yu, Yong; Armstrong, Eric H; Kumari, Manju; Sanor, Lucas; Moore, David D; Ortlund, Eric A; Zechner, Rudolf; Wang, Meng C

    2015-01-01

    Lysosomes are crucial cellular organelles for human health that function in digestion and recycling of extracellular and intracellular macromolecules. We describe a signaling role for lysosomes that affects aging. In the worm Caenorhabditis elegans, the lysosomal acid lipase LIPL-4 triggered nuclear translocalization of a lysosomal lipid chaperone LBP-8, which promoted longevity by activating the nuclear hormone receptors NHR-49 and NHR-80. We used high-throughput metabolomic analysis to identify several lipids in which abundance was increased in worms constitutively overexpressing LIPL-4. Among them, oleoylethanolamide directly bound to LBP-8 and NHR-80 proteins, activated transcription of target genes of NHR-49 and NHR-80, and promoted longevity in C. elegans. These findings reveal a lysosome-to-nucleus signaling pathway that promotes longevity and suggest a function of lysosomes as signaling organelles in metazoans. PMID:25554789

  11. Genomic Analysis of Stress Response against Arsenic in Caenorhabditis elegans

    PubMed Central

    Sahu, Surasri N.; Lewis, Jada; Patel, Isha; Bozdag, Serdar; Lee, Jeong H.; Sprando, Robert; Cinar, Hediye Nese

    2013-01-01

    Arsenic, a known human carcinogen, is widely distributed around the world and found in particularly high concentrations in certain regions including Southwestern US, Eastern Europe, India, China, Taiwan and Mexico. Chronic arsenic poisoning affects millions of people worldwide and is associated with increased risk of many diseases including arthrosclerosis, diabetes and cancer. In this study, we explored genome level global responses to high and low levels of arsenic exposure in Caenorhabditis elegans using Affymetrix expression microarrays. This experimental design allows us to do microarray analysis of dose-response relationships of global gene expression patterns. High dose (0.03%) exposure caused stronger global gene expression changes in comparison with low dose (0.003%) exposure, suggesting a positive dose-response correlation. Biological processes such as oxidative stress, and iron metabolism, which were previously reported to be involved in arsenic toxicity studies using cultured cells, experimental animals, and humans, were found to be affected in C. elegans. We performed genome-wide gene expression comparisons between our microarray data and publicly available C. elegans microarray datasets of cadmium, and sediment exposure samples of German rivers Rhine and Elbe. Bioinformatics analysis of arsenic-responsive regulatory networks were done using FastMEDUSA program. FastMEDUSA analysis identified cancer-related genes, particularly genes associated with leukemia, such as dnj-11, which encodes a protein orthologous to the mammalian ZRF1/MIDA1/MPP11/DNAJC2 family of ribosome-associated molecular chaperones. We analyzed the protective functions of several of the identified genes using RNAi. Our study indicates that C. elegans could be a substitute model to study the mechanism of metal toxicity using high-throughput expression data and bioinformatics tools such as FastMEDUSA. PMID:23894281

  12. A soil bioassay using the nematode Caenorhabditis elegans

    SciTech Connect

    Freeman, M.N.; Peredney, C.L.; Williams, P.L.

    1999-07-01

    Caenorhabditis elegans is a free-livings soil nematode that is commonly used as a biological model. Recently, much work has been done using the nematode as a toxicological model as well. Much of the work involving C. elegans has been performed in aquatic media, since it lives in the interstitial water of soil. However, testing in soil would be expected to more accurately reproduce the organism's normal environment and may take into consideration other factors not available in an aquatic test, i.e., toxicant availability effects due to sorption, various chemical interactions, etc. This study used a modification of a previous experimental protocol to determine 24h LC{sub 50} values for Cu in a Cecil series soil mixture, and examined the use of CuCl{sub 2} as a reference toxicant for soil toxicity testing with C. elegans. Three different methods of determining percent lethality were used, each dependent on how the number of worms missing after the recovery process was used in the lethality calculations. Only tests having {ge}80% worm recovery and {ge}90% control survival were used in determining the LC{sub 50}s, by Probit analysis. The replicate LC{sub 50} values generated a control chart for each method of calculating percent lethality. The coefficient of variation (CV) for each of the three methods was {le}14%. The control charts and the protocol outlined in this study are intended to be used to assess test organism health and monitor precision of future soil toxicity tests with C. elegans.

  13. Nitrosoguanidine and ultraviolet light mutagenesis in Eudorina elegans (chlorophyceae)

    SciTech Connect

    Toby, A.L.; Kemp, C.L.

    1980-06-01

    Reversion of an acetate requiring strain and the induction of sectored colonies are used to establish optimal conditions for nitrosoguanidine and ultraviolet light mutagenesis in Eudorina elegans Ehrenberg. Nitrosoguanidine is more effective in causing reversion of the acetate requiring strain and inducing auxotrophs. Morphogenetic mutants are more readily induced by ultraviolet light. The effectiveness of ultraviolet light as a mutagen is cell cycle dependent whereas the mutagenic action of nitrosoguanidine is not.

  14. Spaceflight and ageing: reflecting on Caenorhabditis elegans in space.

    PubMed

    Honda, Yoko; Honda, Shuji; Narici, Marco; Szewczyk, Nathaniel J

    2014-01-01

    The prospect of space travel continues to capture the imagination. Several competing companies are now promising flights for the general population. Previously, it was recognized that many of the physiological changes that occur with spaceflight are similar to those seen with normal ageing. This led to the notion that spaceflight can be used as a model of accelerated ageing and raised concerns about the safety of individuals engaging in space travel. Paradoxically, however, space travel has been recently shown to be beneficial to some aspects of muscle health in the tiny worm Caenorhabditis elegans. C. elegans is a commonly used laboratory animal for studying ageing. C. elegans displays age-related decline of some biological processes observed in ageing humans, and about 35% of C. elegans' genes have human homologs. Space flown worms were found to have decreased expression of a number of genes that increase lifespan when expressed at lower levels. These changes were accompanied by decreased accumulation of toxic protein aggregates in ageing worms' muscles. Thus, in addition to spaceflight producing physiological changes that are similar to accelerated ageing, it also appears to produce some changes similar to delayed ageing. Here, we put forward the hypothesis that in addition to the previously well-appreciated mechanotransduction changes, neural and endocrine signals are altered in response to spaceflight and that these may have both negative (e.g. less muscle protein) and some positive consequences (e.g. healthier muscles), at least for invertebrates, with respect to health in space. Given that changes in circulating hormones are well documented with age and in astronauts, our view is that further research into the relationship between metabolic control, ageing, and adaptation to the environment should be productive in advancing our understanding of the physiology of both spaceflight and ageing. PMID:24217152

  15. Using Caenorhabditis elegans as a Model for Obesity Pharmacology Development.

    PubMed

    Zheng, Jolene; Vasselli, Joseph R; King, Jason F; King, Michael L; We, Wenqian; Fitzpatrick, Zachary; Johnson, William D; Finley, John W; Martin, Roy J; Keenan, Michael J; Enright, Frederic M; Greenway, Frank L

    2014-05-01

    The Caenorhabditis elegans model is a rapid and inexpensive method to address pharmacologic questions. We describe the use of C. elegans to explore 2 pharmacologic questions concerning candidate antiobesity drugs and illustrate its potential usefulness in pharmacologic research: (1) to determine a ratio of betahistine-olanzapine that blocks the olanzapine-induced intestinal fat deposition (IFD) as detected by Nile red staining and (2) to identify the mechanism of action of a pharmaceutical candidate AB-101 that reduces IFD. Olanzapine (53 μg/mL) increased the IFD (12.1 ± 0.1%, P < 0.02), which was blocked by betahistine (763 μg/mL, 39.3 ± 0.01%, P < 0.05) in wild-type C. elegans (N2). AB-101 (1.0%) reduced the IFD in N2 (P < 0.05), increased the pharyngeal pumping rate (P < 0.05), and reversed the elevated IFD induced by protease inhibitors atazanavir and ritonavir (P < 0.05). AB-101 did not affect IFD in a ACS null mutant strain acs-4(ok2872) III/hT2[bli-4(e937) let-?(q782) qIs48](I;III) suggesting an involvement of the lipid oxidation pathway and an upregulation of CPT-1. Our studies suggest that C. elegans may be used as a resource in pharmacologic research. This article is intended to stimulate a greater appreciation of its value in the development of new pharmaceutical interventions. PMID:24786852

  16. Genomic analysis of stress response against arsenic in Caenorhabditis elegans.

    PubMed

    Sahu, Surasri N; Lewis, Jada; Patel, Isha; Bozdag, Serdar; Lee, Jeong H; Sprando, Robert; Cinar, Hediye Nese

    2013-01-01

    Arsenic, a known human carcinogen, is widely distributed around the world and found in particularly high concentrations in certain regions including Southwestern US, Eastern Europe, India, China, Taiwan and Mexico. Chronic arsenic poisoning affects millions of people worldwide and is associated with increased risk of many diseases including arthrosclerosis, diabetes and cancer. In this study, we explored genome level global responses to high and low levels of arsenic exposure in Caenorhabditis elegans using Affymetrix expression microarrays. This experimental design allows us to do microarray analysis of dose-response relationships of global gene expression patterns. High dose (0.03%) exposure caused stronger global gene expression changes in comparison with low dose (0.003%) exposure, suggesting a positive dose-response correlation. Biological processes such as oxidative stress, and iron metabolism, which were previously reported to be involved in arsenic toxicity studies using cultured cells, experimental animals, and humans, were found to be affected in C. elegans. We performed genome-wide gene expression comparisons between our microarray data and publicly available C. elegans microarray datasets of cadmium, and sediment exposure samples of German rivers Rhine and Elbe. Bioinformatics analysis of arsenic-responsive regulatory networks were done using FastMEDUSA program. FastMEDUSA analysis identified cancer-related genes, particularly genes associated with leukemia, such as dnj-11, which encodes a protein orthologous to the mammalian ZRF1/MIDA1/MPP11/DNAJC2 family of ribosome-associated molecular chaperones. We analyzed the protective functions of several of the identified genes using RNAi. Our study indicates that C. elegans could be a substitute model to study the mechanism of metal toxicity using high-throughput expression data and bioinformatics tools such as FastMEDUSA. PMID:23894281

  17. Caenorhabditis elegans Mutants Resistant to Attachment of Yersinia Biofilms

    PubMed Central

    Darby, Creg; Chakraborti, Amrita; Politz, Samuel M.; Daniels, Calvin C.; Tan, Li; Drace, Kevin

    2007-01-01

    The detailed composition and structure of the Caenorhabditis elegans surface are unknown. Previous genetic studies used antibody or lectin binding to identify srf genes that play roles in surface determination. Infection by Microbacterium nematophilum identified bus (bacterially unswollen) genes that also affect surface characteristics. We report that biofilms produced by Yersinia pestis and Y. pseudotuberculosis, which bind the C. elegans surface predominantly on the head, can be used to identify additional surface-determining genes. A screen for C. elegans mutants with a biofilm absent on the head (Bah) phenotype identified three novel genes: bah-1, bah-2, and bah-3. The bah-1 and bah-2 mutants have slightly fragile cuticles but are neither Srf nor Bus, suggesting that they are specific for surface components involved in biofilm attachment. A bah-3 mutant has normal cuticle integrity, but shows a stage-specific Srf phenotype. The screen produced alleles of five known surface genes: srf-2, srf-3, bus-4, bus-12, and bus-17. For the X-linked bus-17, a paternal effect was observed in biofilm assays. PMID:17339204

  18. RNAi screening to identify postembryonic phenotypes in C. elegans.

    PubMed

    Beifuss, Katherine K; Gumienny, Tina L

    2012-01-01

    C. elegans has proven to be a valuable model system for the discovery and functional characterization of many genes and gene pathways. More sophisticated tools and resources for studies in this system are facilitating continued discovery of genes with more subtle phenotypes or roles. Here we present a generalized protocol we adapted for identifying C. elegans genes with postembryonic phenotypes of interest using RNAi. This procedure is easily modified to assay the phenotype of choice, whether by light or fluorescence optics on a dissecting or compound microscope. This screening protocol capitalizes on the physical assets of the organism and molecular tools the C. elegans research community has produced. As an example, we demonstrate the use of an integrated transgene that expresses a fluorescent product in an RNAi screen to identify genes required for the normal localization of this product in late stage larvae and adults. First, we used a commercially available genomic RNAi library with full-length cDNA inserts. This library facilitates the rapid identification of multiple candidates by RNAi reduction of the candidate gene product. Second, we generated an integrated transgene that expresses our fluorecently tagged protein of interest in an RNAi-sensitive background. Third, by exposing hatched animals to RNAi, this screen permits identification of gene products that have a vital embryonic role that would otherwise mask a post-embryonic role in regulating the protein of interest. Lastly, this screen uses a compound microscope equipped for single cell resolution. PMID:22353760

  19. Genome Editing in C. elegans and Other Nematode Species.

    PubMed

    Sugi, Takuma

    2016-01-01

    Caenorhabditis elegans, a 1 mm long free-living nematode, is a popular model animal that has been widely utilized for genetic investigations of various biological processes. Characteristic features that make C. elegans a powerful model of choice for eukaryotic genetic studies include its rapid life cycle (development from egg to adult in 3.5 days at 20 °C), well-annotated genome, simple morphology (comprising only 959 somatic cells in the hermaphrodite), and transparency (which facilitates non-invasive fluorescence observations). However, early approaches to introducing mutations in the C. elegans genome, such as chemical mutagenesis and imprecise excision of transposons, have required large-scale mutagenesis screens. To avoid this laborious and time-consuming procedure, genome editing technologies have been increasingly used in nematodes including C. briggsae and Pristionchus pacificus, thereby facilitating their genetic analyses. Here, I review the recent progress in genome editing technologies using zinc-finger nucleases (ZFNs), transcriptional activator-like nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in nematodes and offer perspectives on their use in the future. PMID:26927083

  20. Homologue pairing, recombination and segregation in Caenorhabditis elegans.

    PubMed

    Zetka, M

    2009-01-01

    Meiosis in the free-living, hermaphroditic nematode Caenorhabditis elegans is marked by the same highly conserved features observed in other sexually reproducing systems. Accurate chromosome segregation at the meiotic divisions depends on earlier landmark events of meiotic prophase, including the pairing of homologous chromosomes, synapsis between them, and the formation of crossovers. Dissection of these processes has revealed a unique simplification of meiotic mechanisms that impact the interpretation of meiotic chromosome behaviour in more complex systems. Chromosome sites required for chromosome pairing are consolidated to one end of each chromosome, the many sites of recombination initiation are resolved into a single crossover for each chromosome pair, and the diffuse (holocentric) kinetic activity that extends along the length of the mitotic chromosomes is reduced to a single end of each meiotic chromosome. Consequently, studies from the nematode have illuminated and challenged long-standing concepts of homologue pairing mechanisms, crossover interference, and kinetochore structure. Because chromosome pairing, synapsis, and recombination can proceed independently of one another, C. elegans has provided a simplified system for studying these processes and the mechanisms mediating their coordination during meiosis. This review covers the major features of C. elegans meiosis with emphasis on its contributions to understanding essential meiotic processes. PMID:18948706

  1. A Caenorhabditis elegans Genome-Scale Metabolic Network Model.

    PubMed

    Yilmaz, L Safak; Walhout, Albertha J M

    2016-05-25

    Caenorhabditis elegans is a powerful model to study metabolism and how it relates to nutrition, gene expression, and life history traits. However, while numerous experimental techniques that enable perturbation of its diet and gene function are available, a high-quality metabolic network model has been lacking. Here, we reconstruct an initial version of the C. elegans metabolic network. This network model contains 1,273 genes, 623 enzymes, and 1,985 metabolic reactions and is referred to as iCEL1273. Using flux balance analysis, we show that iCEL1273 is capable of representing the conversion of bacterial biomass into C. elegans biomass during growth and enables the predictions of gene essentiality and other phenotypes. In addition, we demonstrate that gene expression data can be integrated with the model by comparing metabolic rewiring in dauer animals versus growing larvae. iCEL1273 is available at a dedicated website (wormflux.umassmed.edu) and will enable the unraveling of the mechanisms by which different macro- and micronutrients contribute to the animal's physiology. PMID:27211857

  2. HES-Mediated Repression of Pten in Caenorhabditis elegans

    PubMed Central

    Chou, Han Ting; Vazquez, Raymarie Gomez; Wang, Kun; Campbell, Richard; Milledge, Gaolin Zheng; Walthall, Walter W.; Johnson, Casonya M.

    2015-01-01

    The hairy/enhancer-of-split (HES) group of transcription factors controls embryonic development, often by acting downstream of the Notch signaling pathway; however, little is known about postembryonic roles of these proteins. In Caenorhabditis elegans, the six proteins that make up the REF-1 family are considered to be HES orthologs that act in both Notch-dependent and Notch-independent pathways to regulate embryonic events. To further our understanding of how the REF-1 family works to coordinate postembryonic cellular events, we performed a functional characterization of the REF-1 family member, HLH-25. We show that, after embryogenesis, hlh-25 expression persists throughout every developmental stage, including dauer, into adulthood. Like animals that carry loss-of-function alleles in genes required for normal cell-cycle progression, the phenotypes of hlh-25 animals include reduced brood size, unfertilized oocytes, and abnormal gonad morphology. Using gene expression microarray, we show that the HLH-25 transcriptional network correlates with the phenotypes of hlh-25 animals and that the C. elegans Pten ortholog, daf-18, is one major hub in the network. Finally, we show that HLH-25 regulates C. elegans lifespan and dauer recovery, which correlates with a role in the transcriptional repression of daf-18 activity. Collectively, these data provide the first genetic evidence that HLH-25 may be a functional ortholog of mammalian HES1, which represses PTEN activity in mice and human cells. PMID:26438299

  3. Mechanistic analysis of the search behaviour of Caenorhabditis elegans

    PubMed Central

    Salvador, Liliana C. M.; Bartumeus, Frederic; Levin, Simon A.; Ryu, William S.

    2014-01-01

    A central question in movement research is how animals use information and movement to promote encounter success. Current random search theory identifies reorientation patterns as key to the compromise between optimizing encounters for both nearby and faraway targets, but how the balance between intrinsic motor programmes and previous environmental experience determines the occurrence of these reorientation behaviours remains unknown. We used high-resolution tracking and imaging data to describe the complete motor behaviour of Caenorhabditis elegans when placed in a novel environment (one in which food is absent). Movement in C. elegans is structured around different reorientation behaviours, and we measured how these contributed to changing search strategies as worms became familiar with their new environment. This behavioural transition shows that different reorientation behaviours are governed by two processes: (i) an environmentally informed ‘extrinsic’ strategy that is influenced by recent experience and that controls for area-restricted search behaviour, and (ii) a time-independent, ‘intrinsic’ strategy that reduces spatial oversampling and improves random encounter success. Our results show how movement strategies arise from a balance between intrinsic and extrinsic mechanisms, that search behaviour in C. elegans is initially determined by expectations developed from previous environmental experiences, and which reorientation behaviours are modified as information is acquired from new environments. PMID:24430127

  4. DNA methylation on N6-adenine in C. elegans

    PubMed Central

    Greer, Eric Lieberman; Blanco, Mario Andres; Gu, Lei; Sendinc, Erdem; Liu, Jianzhao; Aristizábal-Corrales, David; Hsu, Chih-Hung; Aravind, L.; He, Chuan; Shi, Yang

    2015-01-01

    Summary In mammalian cells, DNA methylation on the 5th position of cytosine (5mC) plays an important role as an epigenetic mark. However, DNA methylation was considered to be absent in C. elegans because of the lack of detectable 5mC as well as homologs of the cytosine DNA methyltransferases. Here, using multiple approaches, we demonstrate the presence of adenine N6-methylation (6mA) in C. elegans DNA. We further demonstrate that this modification increases trans-generationally in a paradigm of epigenetic inheritance. Importantly, we identify a DNA demethylase, NMAD-1, and a potential DNA methyltransferase, DAMT-1, which regulate 6mA levels and crosstalk between methylation of histone H3K4me2 and 6mA, and control the epigenetic inheritance of phenotypes associated with the loss of the H3K4me2 demethylase spr-5. Together, these data identify a DNA modification in C. elegans and raise the exciting possibility that 6mA may be a carrier of heritable epigenetic information in eukaryotes. PMID:25936839

  5. Tat-mediated protein delivery in living Caenorhabditis elegans

    SciTech Connect

    Delom, Frederic; Fessart, Delphine; Caruso, Marie-Elaine; Chevet, Eric . E-mail: eric.chevet@mcgill.ca

    2007-01-19

    The Tat protein from HIV-1 fused with heterologous proteins traverses biological membranes in a transcellular process called: protein transduction. This has already been successfully exploited in various biological models, but never in the nematode worm Caenorhabditis elegans. TAT-eGFP or GST-eGFP proteins were fed to C. elegans worms, which resulted in the specific localization of Tat-eGFP to epithelial intestinal cells. This system represents an efficient tool for transcellular transduction in C. elegans intestinal cells. Indeed, this approach avoids the use of tedious purification steps to purify the TAT fusion proteins and allows for rapid analyses of the transduced proteins. In addition, it may represent an efficient tool to functionally analyze the mechanisms of protein transduction as well as to complement RNAi/KO in the epithelial intestinal system. To sum up, the advantage of this technology is to combine the potential of bacterial expression system and the Tat-mediated transduction technique in living worm.

  6. Differential expression pattern of UBX family genes in Caenorhabditis elegans

    SciTech Connect

    Yamauchi, Seiji; Sasagawa, Yohei; Ogura, Teru . E-mail: ogura@gpo.kumamoto-u.ac.jp; Yamanaka, Kunitoshi . E-mail: yamanaka@gpo.kumamoto-u.ac.jp

    2007-06-29

    UBX (ubiquitin regulatory X)-containing proteins belong to an evolutionary conserved protein family and determine the specificity of p97/VCP/Cdc48p function by binding as its adaptors. Caenorhabditis elegans was found to possess six UBX-containing proteins, named UBXN-1 to -6. However, no general or specific function of them has been revealed. During the course of understanding not only their function but also specified function of p97, we investigated spatial and temporal expression patterns of six ubxn genes in this study. Transcript analyses showed that the expression pattern of each ubxn gene was different throughout worm's development and may show potential developmental dynamics in their function, especially ubxn-5 was expressed specifically in the spermatogenic germline, suggesting a crucial role in spermatogenesis. In addition, as ubxn-4 expression was induced by ER stress, it would function as an ERAD factor in C. elegans. In vivo expression analysis by using GFP translational fusion constructs revealed that six ubxn genes show distinct expression patterns. These results altogether demonstrate that the expression of all six ubxn genes of C. elegans is differently regulated.

  7. DNA Methylation and Potential for Epigenetic Regulation in Pygospio elegans.

    PubMed

    Kesäniemi, Jenni E; Heikkinen, Liisa; Knott, K Emily

    2016-01-01

    Transitions in developmental mode are common evolutionarily, but how and why they occur is not understood. Developmental mode describes larval phenotypes, including morphology, ecology and behavior of larvae, which typically are generalized across different species. The polychaete worm Pygospio elegans is one of few species polymorphic in developmental mode, with multiple larval phenotypes, providing a possibility to examine the potential mechanisms allowing transitions in developmental mode. We investigated the presence of DNA methylation in P. elegans, and, since maternal provisioning is a key factor determining eventual larval phenotype, we compared patterns of DNA methylation in females during oogenesis in this species. We demonstrate that intragenic CpG site DNA methylation and many relevant genes necessary for DNA methylation occur in P. elegans. Methylation-sensitive AFLP analysis showed that gravid females with offspring differing in larval developmental mode have significantly different methylation profiles and that the females with benthic larvae and non-reproductive females from the same location also differ in their epigenetic profiles. Analysis of CpG sites in transcriptome data supported our findings of DNA methylation in this species and showed that CpG observed/expected ratios differ among females gravid with embryos destined to different developmental modes. The differences in CpG site DNA methylation patterns seen among the samples suggest a potential for epigenetic regulation of gene expression (through DNA methylation) in this species. PMID:27008314

  8. DNA Methylation and Potential for Epigenetic Regulation in Pygospio elegans

    PubMed Central

    Kesäniemi, Jenni E.; Heikkinen, Liisa; Knott, K. Emily

    2016-01-01

    Transitions in developmental mode are common evolutionarily, but how and why they occur is not understood. Developmental mode describes larval phenotypes, including morphology, ecology and behavior of larvae, which typically are generalized across different species. The polychaete worm Pygospio elegans is one of few species polymorphic in developmental mode, with multiple larval phenotypes, providing a possibility to examine the potential mechanisms allowing transitions in developmental mode. We investigated the presence of DNA methylation in P. elegans, and, since maternal provisioning is a key factor determining eventual larval phenotype, we compared patterns of DNA methylation in females during oogenesis in this species. We demonstrate that intragenic CpG site DNA methylation and many relevant genes necessary for DNA methylation occur in P. elegans. Methylation-sensitive AFLP analysis showed that gravid females with offspring differing in larval developmental mode have significantly different methylation profiles and that the females with benthic larvae and non-reproductive females from the same location also differ in their epigenetic profiles. Analysis of CpG sites in transcriptome data supported our findings of DNA methylation in this species and showed that CpG observed/expected ratios differ among females gravid with embryos destined to different developmental modes. The differences in CpG site DNA methylation patterns seen among the samples suggest a potential for epigenetic regulation of gene expression (through DNA methylation) in this species. PMID:27008314

  9. RNAi-Mediated Inactivation of Autophagy Genes in Caenorhabditis elegans.

    PubMed

    Palmisano, Nicholas J; Meléndez, Alicia

    2016-02-01

    RNA interference (RNAi) is a process that results in the sequence-specific silencing of endogenous mRNA through the introduction of double-stranded RNA (dsRNA). In the nematode Caenorhabditis elegans, RNA inactivation can be used at any specific developmental stage or during adulthood to inhibit a given target gene. Investigators can take advantage of the fact that, in C. elegans, RNAi is unusual in that it is systemic, meaning that dsRNA can spread throughout the animal and can affect virtually all tissues except neurons. Here, we describe a protocol for the most common method to achieve RNAi in C. elegans, which is to feed them bacteria that express dsRNA complementary to a specific target gene. This method has various advantages, including the availability of libraries that essentially cover the whole genome, the ability to treat animals at any developmental stage, and that it is relatively cost effective. We also discuss how RNAi specific to autophagy genes has proven to be an excellent method to study the role of these genes in autophagy, as well as other cellular and developmental processes, while also highlighting the caveats that must be applied. PMID:26832686

  10. Pan-neuronal imaging in roaming Caenorhabditis elegans.

    PubMed

    Venkatachalam, Vivek; Ji, Ni; Wang, Xian; Clark, Christopher; Mitchell, James Kameron; Klein, Mason; Tabone, Christopher J; Florman, Jeremy; Ji, Hongfei; Greenwood, Joel; Chisholm, Andrew D; Srinivasan, Jagan; Alkema, Mark; Zhen, Mei; Samuel, Aravinthan D T

    2016-02-23

    We present an imaging system for pan-neuronal recording in crawling Caenorhabditis elegans. A spinning disk confocal microscope, modified for automated tracking of the C. elegans head ganglia, simultaneously records the activity and position of ∼80 neurons that coexpress cytoplasmic calcium indicator GCaMP6s and nuclear localized red fluorescent protein at 10 volumes per second. We developed a behavioral analysis algorithm that maps the movements of the head ganglia to the animal's posture and locomotion. Image registration and analysis software automatically assigns an index to each nucleus and calculates the corresponding calcium signal. Neurons with highly stereotyped positions can be associated with unique indexes and subsequently identified using an atlas of the worm nervous system. To test our system, we analyzed the brainwide activity patterns of moving worms subjected to thermosensory inputs. We demonstrate that our setup is able to uncover representations of sensory input and motor output of individual neurons from brainwide dynamics. Our imaging setup and analysis pipeline should facilitate mapping circuits for sensory to motor transformation in transparent behaving animals such as C. elegans and Drosophila larva. PMID:26711989

  11. Direct micro-mechanical measurements on C. elegans

    NASA Astrophysics Data System (ADS)

    Backholm, Matilda; Ryu, William S.; Dalnoki-Veress, Kari

    2013-03-01

    The millimeter-sized nematode Caenorhabditis elegans provides an excellent biophysical system for both static and dynamic biomechanical studies. The undulatory motion exhibited by this model organism as it crawls or swims through a medium is ubiquitous in nature at scales from microns to meters. A successful description of this form of locomotion requires knowledge of the material properties of the crawler, as well as its force output as it moves. Here we present an experimental technique with which the material properties and dynamics of C. elegans can be directly probed. By using the deflection of a flexible micropipette, the bending stiffness of C. elegans has been measured at all stages of its life cycle, as well as along the body of the adult worm. The mechanical properties of the worm are modelled as a viscoelastic material which provides new insights into its material properties. The forces exerted by the worm during undulatory motion are also discussed. Direct experimental characterization of this model organism provides guidance for theoretical treatments of undulatory locomotion in general.

  12. Genotype-dependent lifespan effects in peptone deprived Caenorhabditis elegans

    PubMed Central

    Stastna, Jana J.; Snoek, L. Basten; Kammenga, Jan E.; Harvey, Simon C.

    2015-01-01

    Dietary restriction appears to act as a general non-genetic mechanism that can robustly prolong lifespan. There have however been reports in many systems of cases where restricted food intake either shortens, or does not affect, lifespan. Here we analyze lifespan and the effect of food restriction via deprived peptone levels on lifespan in wild isolates and introgression lines (ILs) of the nematode Caenorhabditis elegans. These analyses identify genetic variation in lifespan, in the effect of this variation in diet on lifespan and also in the likelihood of maternal, matricidal, hatching. Importantly, in the wild isolates and the ILs, we identify genotypes in which peptone deprivation mediated dietary restriction reduces lifespan. We also identify, in recombinant inbred lines, a locus that affects maternal hatching, a phenotype closely linked to dietary restriction in C. elegans. These results indicate that peptone deprivation mediated dietary restriction affects lifespan in C. elegans in a genotype-dependent manner, reducing lifespan in some genotypes. This may operate by a mechanism similar to dietary restriction. PMID:26539794

  13. Genome Editing in C. elegans and Other Nematode Species

    PubMed Central

    Sugi, Takuma

    2016-01-01

    Caenorhabditis elegans, a 1 mm long free-living nematode, is a popular model animal that has been widely utilized for genetic investigations of various biological processes. Characteristic features that make C. elegans a powerful model of choice for eukaryotic genetic studies include its rapid life cycle (development from egg to adult in 3.5 days at 20 °C), well-annotated genome, simple morphology (comprising only 959 somatic cells in the hermaphrodite), and transparency (which facilitates non-invasive fluorescence observations). However, early approaches to introducing mutations in the C. elegans genome, such as chemical mutagenesis and imprecise excision of transposons, have required large-scale mutagenesis screens. To avoid this laborious and time-consuming procedure, genome editing technologies have been increasingly used in nematodes including C. briggsae and Pristionchus pacificus, thereby facilitating their genetic analyses. Here, I review the recent progress in genome editing technologies using zinc-finger nucleases (ZFNs), transcriptional activator-like nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in nematodes and offer perspectives on their use in the future. PMID:26927083

  14. Methods to Assess Subcellular Compartments of Muscle in C. elegans

    PubMed Central

    Gaffney, Christopher J.; Bass, Joseph J.; Barratt, Thomas F.; Szewczyk, Nathaniel J.

    2014-01-01

    Muscle is a dynamic tissue that responds to changes in nutrition, exercise, and disease state. The loss of muscle mass and function with disease and age are significant public health burdens. We currently understand little about the genetic regulation of muscle health with disease or age. The nematode C. elegans is an established model for understanding the genomic regulation of biological processes of interest. This worm’s body wall muscles display a large degree of homology with the muscles of higher metazoan species. Since C. elegans is a transparent organism, the localization of GFP to mitochondria and sarcomeres allows visualization of these structures in vivo. Similarly, feeding animals cationic dyes, which accumulate based on the existence of a mitochondrial membrane potential, allows the assessment of mitochondrial function in vivo. These methods, as well as assessment of muscle protein homeostasis, are combined with assessment of whole animal muscle function, in the form of movement assays, to allow correlation of sub-cellular defects with functional measures of muscle performance. Thus, C. elegans provides a powerful platform with which to assess the impact of mutations, gene knockdown, and/or chemical compounds upon muscle structure and function. Lastly, as GFP, cationic dyes, and movement assays are assessed non-invasively, prospective studies of muscle structure and function can be conducted across the whole life course and this at present cannot be easily investigated in vivo in any other organism. PMID:25489753

  15. Caenorhabditis elegans is a useful model for anthelmintic discovery

    PubMed Central

    Burns, Andrew R.; Luciani, Genna M.; Musso, Gabriel; Bagg, Rachel; Yeo, May; Zhang, Yuqian; Rajendran, Luckshika; Glavin, John; Hunter, Robert; Redman, Elizabeth; Stasiuk, Susan; Schertzberg, Michael; Angus McQuibban, G.; Caffrey, Conor R.; Cutler, Sean R.; Tyers, Mike; Giaever, Guri; Nislow, Corey; Fraser, Andy G.; MacRae, Calum A.; Gilleard, John; Roy, Peter J.

    2015-01-01

    Parasitic nematodes infect one quarter of the world's population and impact all humans through widespread infection of crops and livestock. Resistance to current anthelmintics has prompted the search for new drugs. Traditional screens that rely on parasitic worms are costly and labour intensive and target-based approaches have failed to yield novel anthelmintics. Here, we present our screen of 67,012 compounds to identify those that kill the non-parasitic nematode Caenorhabditis elegans. We then rescreen our hits in two parasitic nematode species and two vertebrate models (HEK293 cells and zebrafish), and identify 30 structurally distinct anthelmintic lead molecules. Genetic screens of 19 million C. elegans mutants reveal those nematicides for which the generation of resistance is and is not likely. We identify the target of one lead with nematode specificity and nanomolar potency as complex II of the electron transport chain. This work establishes C. elegans as an effective and cost-efficient model system for anthelmintic discovery. PMID:26108372

  16. Isotopic Ratio Outlier Analysis Global Metabolomics of Caenorhabditis elegans

    PubMed Central

    Szewc, Mark A.; Garrett, Timothy; Menger, Robert F.; Yost, Richard A.; Beecher, Chris; Edison, Arthur S.

    2014-01-01

    We demonstrate the global metabolic analysis of Caenorhabditis elegans stress responses using a mass spectrometry-based technique called Isotopic Ratio Outlier Analysis (IROA). In an IROA protocol, control and experimental samples are isotopically labeled with 95% and 5% 13C, and the two sample populations are mixed together for uniform extraction, sample preparation, and LC-MS analysis. This labeling strategy provides several advantages over conventional approaches: 1) compounds arising from biosynthesis are easily distinguished from artifacts, 2) errors from sample extraction and preparation are minimized because the control and experiment are combined into a single sample, 3) measurement of both the molecular weight and the exact number of carbon atoms in each molecule provides extremely accurate molecular formulae, and 4) relative concentrations of all metabolites are easily determined. A heat shock perturbation was conducted on C. elegans to demonstrate this approach. We identified many compounds that significantly changed upon heat shock, including several from the purine metabolism pathway, which we use to demonstrate the approach. The metabolomic response information by IROA may be interpreted in the context of a wealth of genetic and proteomic information available for C. elegans. Furthermore, the IROA protocol can be applied to any organism that can be isotopically labeled, making it a powerful new tool in a global metabolomics pipeline. PMID:24274725

  17. Autophagy and apoptosis are redundantly required for C. elegans embryogenesis.

    PubMed

    Borsos, Eva; Erdélyi, Péter; Vellai, Tibor

    2011-05-01

    Apoptosis, the main form of regulated (or programmed) cell death, allows the organism to tightly control cell numbers and tissue size, and to protect itself from potentially damaging cells. This type of cellular self-killing has long been assumed to be essential for early development. In the nematode Caenorhabditis elegans, however, the core apoptotic cell death pathway appears to be dispensable for embryogenesis when most developmental cell deaths take place: mutant nematodes defective for apoptosis develop into adulthood, with superficially normal morphology and behavior. Accumulating evidence indicates a similar situation in mammalian systems as well. For example, apoptosis-deficient mice can grow as healthy, fertile adults. These observations raise the possibility that alternative cell death mechanisms may compensate for the lack of apoptotic machinery in developing embryos. Interestingly, C. elegans embryogenesis can also occur without autophagy, an alternative form of cellular self-destruction (also called autophagic cell death). In an upcoming paper we report that simultaneous inactivation of the autophagic and apoptotic gene cascades in C. elegans arrests development at early stages, and the affected embryos exhibit severe morphological defects. Double-mutant nematode embryos deficient in both autophagy and apoptosis are unable to undergo body elongation or to arrange several tissues correctly. This novel function of autophagy genes in morphogenesis indicates a more fundamental role for cellular self-digestion in tissue patterning than previously thought. PMID:21285529

  18. Exposure to Mitochondrial Genotoxins and Dopaminergic Neurodegeneration in Caenorhabditis elegans

    PubMed Central

    Bodhicharla, Rakesh K.; McKeever, Madeline G.; Arrant, Andrew E.; Margillo, Kathleen M.; Ryde, Ian T.; Cyr, Derek D.; Kosmaczewski, Sara G.; Hammarlund, Marc; Meyer, Joel N.

    2014-01-01

    Neurodegeneration has been correlated with mitochondrial DNA (mtDNA) damage and exposure to environmental toxins, but causation is unclear. We investigated the ability of several known environmental genotoxins and neurotoxins to cause mtDNA damage, mtDNA depletion, and neurodegeneration in Caenorhabditis elegans. We found that paraquat, cadmium chloride and aflatoxin B1 caused more mitochondrial than nuclear DNA damage, and paraquat and aflatoxin B1 also caused dopaminergic neurodegeneration. 6-hydroxydopamine (6-OHDA) caused similar levels of mitochondrial and nuclear DNA damage. To further test whether the neurodegeneration could be attributed to the observed mtDNA damage, C. elegans were exposed to repeated low-dose ultraviolet C radiation (UVC) that resulted in persistent mtDNA damage; this exposure also resulted in dopaminergic neurodegeneration. Damage to GABAergic neurons and pharyngeal muscle cells was not detected. We also found that fasting at the first larval stage was protective in dopaminergic neurons against 6-OHDA-induced neurodegeneration. Finally, we found that dopaminergic neurons in C. elegans are capable of regeneration after laser surgery. Our findings are consistent with a causal role for mitochondrial DNA damage in neurodegeneration, but also support non mtDNA-mediated mechanisms. PMID:25486066

  19. Genetic dissection of polyunsaturated fatty acid synthesis in Caenorhabditis elegans

    PubMed Central

    Watts, Jennifer L.; Browse, John

    2002-01-01

    Polyunsaturated fatty acids (PUFAs) are important membrane components and precursors of signaling molecules. To investigate the roles of these fatty acids in growth, development, and neurological function in an animal system, we isolated Caenorhabditis elegans mutants deficient in PUFA synthesis by direct analysis of fatty acid composition. C. elegans possesses all the desaturase and elongase activities to synthesize arachidonic acid and eicosapentaenoic acid from saturated fatty acid precursors. In our screen we identified mutants with defects in each fatty acid desaturation and elongation step of the PUFA biosynthetic pathway. The fatty acid compositions of the mutants reveal the substrate preferences of the desaturase and elongase enzymes and clearly demarcate the steps of this pathway. The mutants show that C. elegans does not require n3 or Δ5-unsaturated PUFAs for normal development under laboratory conditions. However, mutants with more severe PUFA deficiencies display growth and neurological defects. The mutants provide tools for investigating the roles of PUFAs in membrane biology and cell function in this animal model. PMID:11972048

  20. Specioside ameliorates oxidative stress and promotes longevity in Caenorhabditis elegans.

    PubMed

    Asthana, Jyotsna; Yadav, A K; Pant, Aakanksha; Pandey, Swapnil; Gupta, M M; Pandey, Rakesh

    2015-03-01

    Specioside (6-O-coumaroylcatalpol) is an iridoid glucoside which possesses multifunctional activities viz. analgesic, antidyspeptic, astringent, liver stimulating and wound healing properties. The present study for the first time delineates stress alleviating and lifespan prolonging action of specioside (SPC), isolated from Stereospermum suaveolens in the free living, multicellular nematode model Caenorhabditis elegans. A strong correlation between lifespan extension and stress modulation in adult worms was established in a dose dependent manner. The dietary intake of this phytomolecule elevated juglone induced oxidative and heat induced thermal stress tolerance in C. elegans. On evaluation, it was found that 25 μM dose of SPC significantly extended lifespan by 15.47% (P≤0.0001) with reduction in stress level. Furthermore, SPC enhanced mean survival in mev-1 mutant suggesting its oxidative stress reducing potential. Furthermore, SPC augmented stress modulatory enzymes superoxide dismutase (SOD) and catalase (CAT) level in C. elegans. Altogether, these findings broaden current perspectives concerning stress alleviating potentials of SPC and have implications in development of therapeutics for curing age related disorders. PMID:25619942

  1. The assembly and maintenance of epithelial junctions in C. elegans

    PubMed Central

    Lynch, Allison M.; Hardin, Jeff

    2010-01-01

    The epithelial tissues of the C. elegans embryo provide a “minimalist” system for examining phylogenetically conserved proteins that function in epithelial polarity and cell-cell adhesion in a multicellular organism. In this review, we provide an overview of three major molecular complexes at the apical surface of epithelial cells in the C. elegans embryo: the cadherin-catenin complex, the more basal DLG-1/AJM-1 complex, and the apical membrane domain, which shares similarities with the subapical complex in Drosophila and the PAR/aPKC complex in vertebrates. We discuss how the assembly of these complexes contributes to epithelial polarity and adhesion, proteins that act as effectors and/or regulators of each subdomain, and how these complexes functionally interact during embryonic morphogenesis. Although much remains to be clarified, significant progress has been made in recent years to clarify the role of these protein complexes in epithelial morphogenesis, and suggests that C. elegans will continue to be a fruitful system in which to elucidate functional roles for these proteins in a living embryo. PMID:19273138

  2. Mapping and analysis of Caenorhabditis elegans transcription factor sequence specificities

    PubMed Central

    Narasimhan, Kamesh; Lambert, Samuel A; Yang, Ally WH; Riddell, Jeremy; Mnaimneh, Sanie; Zheng, Hong; Albu, Mihai; Najafabadi, Hamed S; Reece-Hoyes, John S; Fuxman Bass, Juan I; Walhout, Albertha JM; Weirauch, Matthew T; Hughes, Timothy R

    2015-01-01

    Caenorhabditis elegans is a powerful model for studying gene regulation, as it has a compact genome and a wealth of genomic tools. However, identification of regulatory elements has been limited, as DNA-binding motifs are known for only 71 of the estimated 763 sequence-specific transcription factors (TFs). To address this problem, we performed protein binding microarray experiments on representatives of canonical TF families in C. elegans, obtaining motifs for 129 TFs. Additionally, we predict motifs for many TFs that have DNA-binding domains similar to those already characterized, increasing coverage of binding specificities to 292 C. elegans TFs (∼40%). These data highlight the diversification of binding motifs for the nuclear hormone receptor and C2H2 zinc finger families and reveal unexpected diversity of motifs for T-box and DM families. Motif enrichment in promoters of functionally related genes is consistent with known biology and also identifies putative regulatory roles for unstudied TFs. DOI: http://dx.doi.org/10.7554/eLife.06967.001 PMID:25905672

  3. Mating Damages the Cuticle of C. elegans Hermaphrodites

    PubMed Central

    Woodruff, Gavin C.; Knauss, Christine M.; Maugel, Timothy K.; Haag, Eric S.

    2014-01-01

    Lifespan costs to reproduction are common across multiple species, and such costs could potentially arise through a number of mechanisms. In the nematode Caenorhabditis elegans, it has been suggested that part of the lifespan cost to hermaphrodites from mating results from physical damage owing to the act of copulation itself. Here, we examine whether mating damages the surface of the hermaphrodite cuticle via scanning electron microscopy. It is found that mated hermaphrodites suffered delamination of cuticle layers surrounding the vulva, and that the incidence of such damage depends on genetic background. Unmated hermaphrodites demonstrated almost no such damage, even when cultured in soil with potentially abrasive particles. Thus, a consequence of mating for C. elegans hermaphrodites is physical cuticle damage. These experiments did not assess the consequences of cuticle damage for lifespan, and the biological significance of this damage remains unclear. We further discuss our results within the context of recent studies linking the lifespan cost to mating in C. elegans hermaphrodites to male secretions. PMID:25105881

  4. Control of Oocyte Growth and Meiotic Maturation in C. elegans

    PubMed Central

    Kim, Seongseop; Spike, Caroline; Greenstein, David

    2013-01-01

    In sexually reproducing animals, oocytes arrest at diplotene or diakinesis and resume meiosis (meiotic maturation) in response to hormones. Chromosome segregation errors in female meiosis I are the leading cause of human birth defects, and age-related changes in the hormonal environment of the ovary are a suggested cause. C. elegans is emerging as a genetic paradigm for studying hormonal control of meiotic maturation. The meiotic maturation processes in C. elegans and mammals share a number of biological and molecular similarities. Major sperm protein (MSP) and luteinizing hormone (LH), though unrelated in sequence, both trigger meiotic resumption using somatic Gαs-adenylate cyclase pathways and soma-germline gap-junctional communication. At a molecular level, the oocyte responses apparently involve the control of conserved protein kinase pathways and post-transcriptional gene regulation in the oocyte. At a cellular level, the responses include cortical cytoskeletal rearrangement, nuclear envelope breakdown, assembly of the acentriolar meiotic spindle, chromosome segregation, and likely changes important for fertilization and the oocyte-to-embryo transition. This chapter focuses on signaling mechanisms required for oocyte growth and meiotic maturation in C. elegans and discusses how these mechanisms coordinate the completion of meiosis and the oocyte-to-embryo transition. PMID:22872481

  5. A method for measuring fatty acid oxidation in C. elegans.

    PubMed

    Elle, Ida Coordt; Rødkær, Steven Vestergaard; Fredens, Julius; Færgeman, Nils Joakim

    2012-01-01

    The nematode C. elegans has during the past decade proven to be a valuable model organism to identify and examine molecular mechanisms regulating lipid storage and metabolism. While the primary approach has been to identify genes and pathways conferring alterations in lipid accumulation, only a few recent studies have recognized the central role of fatty acid degradation in cellular lipid homeostasis. In the present study, we show how complete oxidation of fatty acids can be determined in live C. elegans by examining oxidation of tritium-labeled fatty acids to tritiated H2O that can be measured by scintillation counting. Treating animals with sodium azide, an inhibitor of the electron transport chain, reduced (3)H2O production to approximately 15%, while boiling of animals prior to assay completely blocked the production of labeled water. We demonstrate that worms fed different bacterial strains exhibit different fatty acid oxidation rates. We show that starvation results in increased fatty acid oxidation, which is independent of the transcription factor NHR-49. On the contrary, fatty acid oxidation is reduced to approximately 70% in animals lacking the worm homolog of the insulin receptor, DAF-2. Hence, the present methodology can be used to delineate the role of specific genes and pathways in the regulation of β-oxidation in C. elegans. PMID:24058820

  6. Optical reversal of halothane-induced immobility in C. elegans.

    PubMed

    Singaram, Vinod K; Somerlot, Benjamin H; Falk, Scott A; Falk, Marni J; Sedensky, Margaret M; Morgan, Philip G

    2011-12-20

    Volatile anesthetics (VAs) cause profound neurological effects, including reversible loss of consciousness and immobility. Despite their widespread use, the mechanism of action of VAs remains one of the unsolved puzzles of neuroscience [1, 2]. Genetic studies in Caenorhabditis elegans [3, 4], Drosophila [3, 5], and mice [6-9] indicate that ion channels controlling the neuronal resting membrane potential (RMP) also control anesthetic sensitivity. Leak channels selective for K(+) [10-13] or permeable to Na(+) [14] are critical for establishing RMP. We hypothesized that halothane, a VA, caused immobility by altering the neuronal RMP. In C. elegans, halothane-induced immobility is acutely and completely reversed by channelrhodopsin-2 based depolarization of the RMP when expressed specifically in cholinergic neurons. Furthermore, hyperpolarizing cholinergic neurons via halorhodopsin activation increases sensitivity to halothane. The sensitivity of C. elegans to halothane can be altered by 25-fold by either manipulation of membrane conductance with optogenetic methods or generation of mutations in leak channels that set the RMP. Immobility induced by another VA, isoflurane, is not affected by these treatments, thereby excluding the possibility of nonspecific hyperactivity. The sum of our data indicates that leak channels and the RMP are important determinants of halothane-induced general anesthesia. PMID:22137475

  7. Courtship herding in the fiddler crab Uca elegans.

    PubMed

    How, Martin J; Hemmi, Jan M

    2008-12-01

    Male and female animals are not always complicit during reproduction, giving rise to coercion. One example of a system that is assumed to involve sexual coercion is the mate herding behaviour of fiddler crabs: males push females towards the home burrow with the goal of forcing copulation at the burrow entrance. We recorded and analysed in detail the courtship behaviour of a North Australian species of fiddler crab Uca elegans. Courtship was composed of four main phases: broadcast waving, outward run, herding and at burrow display. During interactions males produced claw-waving displays which were directed posteriorly towards the female and which varied in timing and structure depending on the courtship phase. We suggest that courtship herding in U. elegans is driven primarily by mate choice for the following reasons, (1) females can evade herding, (2) no other reproductive strategies were observed, (3) males broadcast their presence and accompany courtship with conspicuous claw waves, and (4) the behaviour ends with the female leading the male into the home burrow. As an alternative function for herding in U. elegans we suggest that the behaviour represents a form of courtship guiding, in which males direct complicit females to the correct home burrow. PMID:18846353

  8. Electrotaxis of Caenorhabditis elegans in a microfluidic environment.

    PubMed

    Rezai, Pouya; Siddiqui, Asad; Selvaganapathy, Ponnambalam Ravi; Gupta, Bhagwati P

    2010-01-21

    The nematode (worm) Caenorhabditis elegans is one of the most widely studied organisms for biomedical research. Currently, C. elegans assays are performed either on petri dishes, 96-well plates or using pneumatically controlled microfluidic devices. In this work, we demonstrate that the electric field can be used as a powerful stimulus to control movement of worms in a microfluidic environment. We found that this response (termed electrotaxis) is directional, fully penetrant and highly sensitive. The characterization of electrotaxis revealed that it is mediated by neuronal activity that varies with the age and size of animals. Although the speed of swimming is unaffected by changes in the electric field strength and direction, our results show that each developmental stage responds to a specific range of electric field with a specific speed. Finally, we provide evidence that the exposure to the electric field has no discernible effect on the ability of animals to survive and reproduce. Our method has potential in precisely controlling, directing, and transporting worms in an efficient and automated manner. This opens up significant possibilities for high-throughput screening of C. elegans for drug discovery and other applications. PMID:20066250

  9. An analysis of behavioral plasticity in male Caenorhabditis elegans.

    PubMed

    Mah, K B; Rankin, C H

    1992-11-01

    Caenorhabditis elegans is a simple soil-dwelling nematode which has two sexes, hermaphrodite and male. The male C. elegans is differentiated from the hermaphrodite by the presence of 14 sensory structures in the tail. In this study, we compared the behavioral responses of males and hermaphrodites to head-touch and to tap. We hypothesized that the anatomical difference in sensory structures might result in behavioral differences in the reversal response to vibratory stimulation (a tap to the side of the holding dish). In the response to increasing intensities of tap, both sexes showed an increase in response magnitude, with the males showing larger responses than hermaphrodites. In addition, the male was shown to be capable of simple nonassociative learning: it demonstrated habituation and recovery from habituation in a similar manner as the hermaphrodite. Tail-touch-induced inhibition of the reversal response appeared to be similar in males and hermaphrodites. The evidence suggests that the touch withdrawal circuit in hermaphrodites is also present in the male C. elegans, and that the subtle differences in response to tap seen in males may result from the additional sensory receptors of the copulatory bursa of the tail. It seems clear from these studies that these structures do not play a key role in the male worm's response to tap. PMID:1456943

  10. Isolated Polynucleotides and Methods of Promoting a Morphology in a Fungus

    DOEpatents

    Lasure, Linda L [Fall City, WA; Dai, Ziyu [Richland, WA

    2008-10-21

    The invention includes isolated polynucleotide molecules that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention includes a method of enhancing a bioprocess utilizing a fungus. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to a promoter. The polynucleotide sequence is expressed to promote a first morphology. The first morphology of the transformed fungus enhances a bioprocess relative to the bioprocess utilizing a second morphology.

  11. Allergens of the entomopathogenic fungus Beauveria bassiana

    PubMed Central

    Westwood, Greg S; Huang, Shih-Wen; Keyhani, Nemat O

    2005-01-01

    Background Beauveria bassiana is an important entomopathogenic fungus currently under development as a bio-control agent for a variety of insect pests. Although reported to be non-toxic to vertebrates, the potential allergenicity of Beauveria species has not been widely studied. Methods IgE-reactivity studies were performed using sera from patients displaying mould hypersensitivity by immunoblot and immunoblot inhibition. Skin reactivity to B. bassiana extracts was measured using intradermal skin testing. Results Immunoblots of fungal extracts with pooled as well as individual sera showed a distribution of IgE reactive proteins present in B. bassiana crude extracts. Proteinase K digestion of extracts resulted in loss of IgE reactive epitopes, whereas EndoH and PNGaseF (glycosidase) treatments resulted in minor changes in IgE reactive banding patterns as determined by Western blots. Immunoblot inhibitions experiments showed complete loss of IgE-binding using self protein, and partial inhibition using extracts from common allergenic fungi including; Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum, Candida albicans, Epicoccum purpurascens, and Penicillium notatum. Several proteins including a strongly reactive band with an approximate molecular mass of 35 kDa was uninhibited by any of the tested extracts, and may represent B. bassiana specific allergens. Intradermal skin testing confirmed the in vitro results, demonstrating allergenic reactions in a number of individuals, including those who have had occupational exposure to B. bassiana. Conclusions Beauveria bassiana possesses numerous IgE reactive proteins, some of which are cross-reactive among allergens from other fungi. A strongly reactive potential B. bassiana specific allergen (35 kDa) was identified. Intradermal skin testing confirmed the allergenic potential of B. bassiana. PMID:15644142

  12. Caenorhabditis elegans, a Biological Model for Research in Toxicology.

    PubMed

    Tejeda-Benitez, Lesly; Olivero-Verbel, Jesus

    2016-01-01

    Caenorhabditis elegans is a nematode of microscopic size which, due to its biological characteristics, has been used since the 1970s as a model for research in molecular biology, medicine, pharmacology, and toxicology. It was the first animal whose genome was completely sequenced and has played a key role in the understanding of apoptosis and RNA interference. The transparency of its body, short lifespan, ability to self-fertilize and ease of culture are advantages that make it ideal as a model in toxicology. Due to the fact that some of its biochemical pathways are similar to those of humans, it has been employed in research in several fields. C. elegans' use as a biological model in environmental toxicological assessments allows the determination of multiple endpoints. Some of these utilize the effects on the biological functions of the nematode and others use molecular markers. Endpoints such as lethality, growth, reproduction, and locomotion are the most studied, and usually employ the wild type Bristol N2 strain. Other endpoints use reporter genes, such as green fluorescence protein, driven by regulatory sequences from other genes related to different mechanisms of toxicity, such as heat shock, oxidative stress, CYP system, and metallothioneins among others, allowing the study of gene expression in a manner both rapid and easy. These transgenic strains of C. elegans represent a powerful tool to assess toxicity pathways for mixtures and environmental samples, and their numbers are growing in diversity and selectivity. However, other molecular biology techniques, including DNA microarrays and MicroRNAs have been explored to assess the effects of different toxicants and samples. C. elegans has allowed the assessment of neurotoxic effects for heavy metals and pesticides, among those more frequently studied, as the nematode has a very well defined nervous system. More recently, nanoparticles are emergent pollutants whose toxicity can be explored using this nematode

  13. Automated Quantification of Synaptic Fluorescence in C. elegans

    PubMed Central

    Sturt, Brianne L.; Bamber, Bruce A.

    2012-01-01

    Synapse strength refers to the amplitude of postsynaptic responses to presynaptic neurotransmitter release events, and has a major impact on overall neural circuit function. Synapse strength critically depends on the abundance of neurotransmitter receptors clustered at synaptic sites on the postsynaptic membrane. Receptor levels are established developmentally, and can be altered by receptor trafficking between surface-localized, subsynaptic, and intracellular pools, representing important mechanisms of synaptic plasticity and neuromodulation. Rigorous methods to quantify synaptically-localized neurotransmitter receptor abundance are essential to study synaptic development and plasticity. Fluorescence microscopy is an optimal approach because it preserves spatial information, distinguishing synaptic from non-synaptic pools, and discriminating among receptor populations localized to different types of synapses. The genetic model organism Caenorhabditis elegans is particularly well suited for these studies due to the small size and relative simplicity of its nervous system, its transparency, and the availability of powerful genetic techniques, allowing examination of native synapses in intact animals. Here we present a method for quantifying fluorescently-labeled synaptic neurotransmitter receptors in C. elegans. Its key feature is the automated identification and analysis of individual synapses in three dimensions in multi-plane confocal microscope output files, tabulating position, volume, fluorescence intensity, and total fluorescence for each synapse. This approach has two principal advantages over manual analysis of z-plane projections of confocal data. First, because every plane of the confocal data set is included, no data are lost through z-plane projection, typically based on pixel intensity averages or maxima. Second, identification of synapses is automated, but can be inspected by the experimenter as the data analysis proceeds, allowing fast and accurate

  14. On-Demand Isolation and Manipulation of C. elegans by In Vitro Maskless Photopatterning.

    PubMed

    Oliver, C Ryan; Gourgou, Eleni; Bazopoulou, Daphne; Chronis, Nikos; Hart, A John

    2016-01-01

    Caenorhabditis elegans (C. elegans) is a model organism for understanding aging and studying animal behavior. Microfluidic assay techniques have brought widespread advances in C. elegans research; however, traditional microfluidic assays such as those based on soft lithography require time-consuming design and fabrication cycles and offer limited flexibility in changing the geometric environment during experimentation. We present a technique for maskless photopatterning of a biocompatible hydrogel on an NGM (Agar) substrate, enabling dynamic manipulation of the C. elegans culture environment in vitro. Maskless photopatterning is performed using a projector-based microscope system largely built from off-the-shelf components. We demonstrate the capabilities of this technique by building micropillar arrays during C. elegans observation, by fabricating free-floating mechanisms that can be actuated by C. elegans motion, by using freehand drawing to isolate individual C. elegans in real time, and by patterning arrays of mazes for isolation and fitness testing of C. elegans populations. In vitro photopatterning enables rapid and flexible design of experiment geometry as well as real-time interaction between the researcher and the assay such as by sequential isolation of individual organisms. Future adoption of image analysis and machine learning techniques could be used to acquire large datasets and automatically adapt the assay geometry. PMID:26730604

  15. Mapping a Mutation in "Caenorhabditis elegans" Using a Polymerase Chain Reaction-Based Approach

    ERIC Educational Resources Information Center

    Myers, Edith M.

    2014-01-01

    Many single nucleotide polymorphisms (SNPs) have been identified within the "Caenorhabditis elegans" genome. SNPs present in the genomes of two isogenic "C. elegans" strains have been routinely used as a tool in forward genetics to map a mutation to a particular chromosome. This article describes a laboratory exercise in which…

  16. A Chemosensory Adaptation Module for the Physiology Laboratory from Student-Directed "C. elegans" Research

    ERIC Educational Resources Information Center

    Lindblom, Tim

    2006-01-01

    The model organism, "Caenorhabditis elegans," in addition to being well suited to genetics and cell biology teaching applications, can also be useful in the physiology laboratory. In this article, the author describes how students in a junior level college Comparative Physiology course have made use of "C. elegans" in semester-long,…

  17. Neuronal regulation of ascaroside response during mate response behavior in the nematode Caenorhabditis elegans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Small-molecule signaling plays an important role in the biology of Caenorhabditis elegans. We have previously shown that ascarosides, glycosides of the dideoxysugar ascarylose regulate both development and behavior in C. elegans The mating signal consists of a synergistic blend of three dauer-induc...

  18. Using RNAi in C. "elegans" to Demonstrate Gene Knockdown Phenotypes in the Undergraduate Biology Lab Setting

    ERIC Educational Resources Information Center

    Roy, Nicole M.

    2013-01-01

    RNA interference (RNAi) is a powerful technology used to knock down genes in basic research and medicine. In 2006 RNAi technology using "Caenorhabditis elegans" ("C. elegans") was awarded the Nobel Prize in medicine and thus students graduating in the biological sciences should have experience with this technology. However,…

  19. Sex Change by Gene Conversion in a Caenorhabditis elegans fog-2 Mutant

    PubMed Central

    Katju, Vaishali; LaBeau, Elisa M.; Lipinski, Kendra J.; Bergthorsson, Ulfar

    2008-01-01

    Caenorhabditis elegans primarily reproduces as a hermaphrodite. Independent gene conversion events in mutant obligately outcrossing populations of C. elegans [fog-2(lf)] spontaneously repaired the loss-of-function mutation in the fog-2 locus, thereby reestablishing hermaphroditism as the primary means of reproduction for the populations. PMID:18757925

  20. Heritable custom genomic modifications in Caenorhabditis elegans via a CRISPR-Cas9 system.

    PubMed

    Tzur, Yonatan B; Friedland, Ari E; Nadarajan, Saravanapriah; Church, George M; Calarco, John A; Colaiácovo, Monica P

    2013-11-01

    We adapted the CRISPR-Cas9 system for template-mediated repair of targeted double-strand breaks via homologous recombination in Caenorhabditis elegans, enabling customized and efficient genome editing. This system can be used to create specific insertions, deletions, and base pair changes in the germline of C. elegans. PMID:23979579

  1. FMRFamide related peptide ligands activate the Caenorhabditis elegans orphan GPCR Y59H11AL.1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    G-protein coupled receptors (GPCRs) are ancient molecules that sense environmental and physiological signals. Currently, the majority of the predicted Caenorhabditis elegans GPCRs are orphan. Here, we describe the characterization of such an orphan C. elegans GPCR, which is categorized in the tachyk...

  2. On-Demand Isolation and Manipulation of C. elegans by In Vitro Maskless Photopatterning

    PubMed Central

    Oliver, C. Ryan; Gourgou, Eleni; Bazopoulou, Daphne; Chronis, Nikos; Hart, A. John

    2016-01-01

    Caenorhabditis elegans (C. elegans) is a model organism for understanding aging and studying animal behavior. Microfluidic assay techniques have brought widespread advances in C. elegans research; however, traditional microfluidic assays such as those based on soft lithography require time-consuming design and fabrication cycles and offer limited flexibility in changing the geometric environment during experimentation. We present a technique for maskless photopatterning of a biocompatible hydrogel on an NGM (Agar) substrate, enabling dynamic manipulation of the C. elegans culture environment in vitro. Maskless photopatterning is performed using a projector-based microscope system largely built from off-the-shelf components. We demonstrate the capabilities of this technique by building micropillar arrays during C. elegans observation, by fabricating free-floating mechanisms that can be actuated by C. elegans motion, by using freehand drawing to isolate individual C. elegans in real time, and by patterning arrays of mazes for isolation and fitness testing of C. elegans populations. In vitro photopatterning enables rapid and flexible design of experiment geometry as well as real-time interaction between the researcher and the assay such as by sequential isolation of individual organisms. Future adoption of image analysis and machine learning techniques could be used to acquire large datasets and automatically adapt the assay geometry. PMID:26730604

  3. A potential biochemical mechanism underlying the influence of sterol deprivation stress on Caenorhabditis elegans longevity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To investigate the biochemical mechanism for sterol-mediated alteration in aging in Caenorhabditis elegans, we established sterol depletion conditions by treating worms with azacoprostane, which reduced mean lifespan of adult C. elegans by 35%. Proteomic analyses of egg proteins from treated and un...

  4. Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"

    ERIC Educational Resources Information Center

    Amano, Hisayuki; Maruyama, Ichiro N.

    2011-01-01

    The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH…

  5. Influence of Silicon on Resistance of Zinnia Elegans to Myzus Persicae (Hemiptera: Aphididae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to examine the effect of treating Zinnia elegans Jacq. with soluble silicon on the performance of the green peach aphid, Myzus persicae (Sulzer). Zinnia elegans plants were irrigated every 2 days throughout the duration of the experiment with a nutrient solution amended with ...

  6. Fish oil changes the lifespan of Caenorhabditis elegans via lipid peroxidation

    PubMed Central

    Sugawara, Soko; Honma, Taro; Ito, Junya; Kijima, Ryo; Tsuduki, Tsuyoshi

    2013-01-01

    Recently, we administered fish oil containing eicosapentaenoic acid and docosahexaenoic acid (DHA) to senescence-accelerated mice P8 (SAMP8), in order to investigate the effects on lifespan. Surprisingly, the lifespan of SAMP8 that were fed fish oil was shortened significantly, through a mechanism that likely involved lipid peroxidation. In this study, we investigated this phenomenon in further detail. To examine whether this phenomenon occurs only in SAMP8, we investigated the effect of fish oil on the lifespan of another organism species, Caenorhabditis elegans (C. elegans). C. elegans fed fish oil were cultured and the lifespan monitored. As a consequence of the provision of large amounts of fish oil the lifespan of C. elegans was shortened significantly, whereas an appropriate amount of fish oil extended their lifespan significantly. Lipid peroxide levels in C. elegans that were fed fish oil increased significantly in a dose-dependent manner. However, lipid peroxide levels in C. elegans were inhibited by the addition of fish oil and an antioxidant, α-tocopherol, and completely abrogated the changes in the lifespan. To further confirm whether the oxidation of n-3 polyunsaturated fatty acid in fish oil would change the lifespan of C. elegans, the effect of oxidized DHA was examined. Large amounts of oxidized DHA were found to shorten their lifespan significantly. Thus, fish oil changes the lifespan of C. elegans through lipid peroxidation. PMID:23526170

  7. Selenite Enhances Immune Response against Pseudomonas aeruginosa PA14 via SKN-1 in Caenorhabditis elegans

    PubMed Central

    Huang, Chi-Wei; Wei, Chia-Cheng; Liao, Vivian Hsiu-Chuan

    2014-01-01

    Background Selenium (Se) is an important nutrient that carries out many biological processes including maintaining optimal immune function. Here, inorganic selenite (Se(IV)) was evaluated for its pathogen resistance and potential-associated factors in Caenorhabditis elegans. The immune effects of Se(IV) were investigated by examining the responses of C. elegans to Pseudomonas aerugonisa PA14 strain. Principal Findings Se(IV)-treated C. elegans showed increased survival under PA14 infection compared with untreated controls. The significant pathogen resistance of Se(IV) on C. elegans might not be attributed to the effects of Se(IV) on PA14 as Se(IV) showed no effect on bacterial quorum-sensing and virulence factors of PA14. This study showed that Se(IV) enhanced the expression of a gene pivotal for the innate immunity in C. elegans. The study found that the pathogen-resistant phenotypes contributed by Se(IV) was absent from the skn-1 mutant worms. Moreover, Se(IV) influenced the subcellular distribution of SKN-1/Nrf in C. elegans upon PA14 infection. Furthermore, Se(IV) increased mRNA levels of SKN-1 target genes (gst-4 and gcs-1). Conclusions This study found evidence of Se(IV) protecting C. elegans against P. aeruginosa PA14 infection by exerting effects on the innate immunity of C. elegans that is likely mediated via regulation of a SKN-1-dependent signaling pathway. PMID:25147937

  8. An endosymbiotic conidial fungus, Scopulariopsis brevicaulis, protects the American dog tick, Dermacentor variabilis, from desiccation imposed by an entomopathogenic fungus.

    PubMed

    Yoder, Jay A; Benoit, Joshua B; Denlinger, David L; Tank, Justin L; Zettler, Lawrence W

    2008-02-01

    The functional role of an endosymbiotic conidial fungus (Scopulariopsis brevicaulis) prevalent within the integumental glands and hemocoel of the American dog tick (Dermacentor variabilis) was investigated to explore the nature of this tick/fungus association. D. variabilis is normally highly resistant to Metarhizium anisopliae, a widely-distributed entomopathogenic fungus, but when mature female ticks harboring S. brevicaulis were fed a solution containing a mycotoxin (Amphotericin B) to purge this mycobiont internally, the ticks inoculated with M. anisopliae displayed classic signs of pathogenicity, as evidenced by recovery of M. anisopliae from ticks by internal fungus culture, greatly accelerated net transpiration water loss rates (nearly 3x faster than ticks containing S. brevicaulis naturally) and elevation of critical equilibrium humidity (CEH) closer to saturation, implying a reduced capacity to absorb water vapor and disruption of water balance (water gain not equal water loss) that resulted in tick death. The presence of S. brevicaulis within the tick was previously puzzling: the fungus is transmitted maternally and there is no apparent harm inflicted to either generation. This study suggests that S. brevicaulis provides protection to D. variabilis ticks against M. anisopliae. Thus, the S. brevicaulis/tick association appears to be mutualistic symbiosis. Given that both organisms are of medical-veterinary importance, disruption of this symbiosis has potential for generating novel tools for disease control. PMID:17880996

  9. Attraction of pinewood nematode to endoparasitic nematophagous fungus Esteya vermicola.

    PubMed

    Wang, Chun Yan; Wang, Zhen; Fang, Zhe Ming; Zhang, Dong Liang; Gu, Li Juan; Liu, Lei; Sung, Chang Keun

    2010-05-01

    The investigations on attraction of nematodes to nematophagous fungi have mostly dealt with the nematode-trapping species. Esteya vermicola is the endoparasitic fungus of pinewood nematode (PWN) with high infection activity. In the present study, the attraction of PWNs to E. vermicola was investigated. It was confirmed that the living mycelia and exudative substances of E. vermicola were attractive to PWN. Compared with the nematode-trapping fungus A. brochopaga as well as nematode-feeding fungus B. cinerea, E. vermicola showed the significantly strongest attraction ability to nematode. It therefore appeared that the attraction ability reflects the dependence of the fungi on nematodes for nutrients. Furthermore, a new method was developed and used in the study to confirm the effect of volatile substances for the attraction of nematode to fungi. The results suggested that the attractive substances were consisted of avolatile exudative and volatile diffusing compounds. PMID:20012046

  10. Source of fungus contamination of hydrophilic soft contact lenses.

    PubMed

    Gasset, A R; Mattingly, T P; Hood, I

    1979-09-01

    Fungus infiltration within hydrophilic lenses has been a rare finding. This case report confirms previous findings that fungal contamination of hydrophilic contact lens is possible. The present report, to our knowledge, is the first demonstration of the association of fungus from contaminated cosmetics with hydrophilic contact lenses. It is important to be aware of the possibility of fungal invasion of hydrophilic lenses, as well as to be able to differentiate this from the more common harmless spot formation. On the basis of this study, good lid hygiene, strict adherence to the sterilization procedure, and discontinuance of any soft hydrophilic contact lenses with spot formation seems appropriate. PMID:556154

  11. Patterns of functional enzyme activity in fungus farming ambrosia beetles

    PubMed Central

    2012-01-01

    Introduction In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae), wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow) and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i) 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii) four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. Results We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4)-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Conclusion Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily accessible hemicellulose

  12. Roles of Peroxisomes in the Rice Blast Fungus

    PubMed Central

    Liu, Caiyun

    2016-01-01

    The rice blast fungus, Magnaporthe oryzae, is a model plant pathogenic fungus and is a severe threat to global rice production. Over the past two decades, it has been found that the peroxisomes play indispensable roles during M. oryzae infection. Given the importance of the peroxisomes for virulence, we review recent advances of the peroxisomes roles during M. oryzae infection processes. We firstly introduce the molecular mechanisms and life cycles of the peroxisomes. And then, metabolic functions related to the peroxisomes are also discussed. Finally, we provide an overview of the relationship between peroxisomes and pathogenicity. PMID:27610388

  13. A new cytosporone derivative from the endophytic fungus Cytospora sp.

    PubMed

    Takano, Tomoya; Koseki, Takuya; Koyama, Hiromasa; Shiono, Yoshihito

    2014-07-01

    Japanese oak wilt (JOW) is a tree disease caused by the fungus Raffaelea quercivora, which is vectored by the ambrosia beetle, Platypus quercivorus. In a screening study of the inhibitory active compounds from fungi, a new cytosporone analogue, compound 1, was isolated from the endophytic fungus Cytospora sp. TT-10 isolated from Japanese oak, together with the known compounds, integracin A (2), cytosporones N (3) and A (4). Their structures were determined by extensive 1D- and 2D-NMR spectroscopic and mass spectral analyses. Compound 1 was identified as 4,5-dihydroxy-3-heptylphthalide and named cytosporone E. Compounds 2 and 3 showed antimicrobial activity against Raffaelea quercivora. PMID:25230507

  14. The soil fungus Chaetomium in the human paranasal sinuses.

    PubMed

    Aru, A; Munk-Nielsen, L; Federspiel, B H

    1997-01-01

    Chaetomium is a soil fungus of which more than 180 species are now known. Most species cause degradation of cellulose-rich substrates, such as components in soil, straw or wood. Growth of Chaetomium globosum is often stimulated in the presence of Aspergillus fumigatus, which excretes such compounds as sugar phosphates and phospho-glyceric acid. A 73-year-old woman, with long-standing pain and secretion from her left maxillary sinus, was admitted to hospital where an infundibulectomy was performed. Histological examination showed necrotic material with hyphae of A. fumigatus and perithecia of Chaetomium sp. The latter fungus is rarely pathogenic to man. PMID:9298672

  15. Roles of Peroxisomes in the Rice Blast Fungus.

    PubMed

    Chen, Xiao-Lin; Wang, Zhao; Liu, Caiyun

    2016-01-01

    The rice blast fungus, Magnaporthe oryzae, is a model plant pathogenic fungus and is a severe threat to global rice production. Over the past two decades, it has been found that the peroxisomes play indispensable roles during M. oryzae infection. Given the importance of the peroxisomes for virulence, we review recent advances of the peroxisomes roles during M. oryzae infection processes. We firstly introduce the molecular mechanisms and life cycles of the peroxisomes. And then, metabolic functions related to the peroxisomes are also discussed. Finally, we provide an overview of the relationship between peroxisomes and pathogenicity. PMID:27610388

  16. Two chlorinated benzofuran derivatives from the marine fungus Pseudallescheria boydii.

    PubMed

    Yan, Dan-Feng; Lan, Wen-Jian; Wang, Kun-Teng; Huang, Lei; Jiang, Cai-Wu; Li, Hou-Jin

    2015-04-01

    The marine fungus Pseudallescheria boydii was isolated from the inner tissue of the starfish Acanthaster planci. This fungus was cultured in a high salinity glucose-peptone-yeast extract (GPY) medium. Two new chlorinated benzofuran derivatives, 6-chloro-2-(2-hydroxypropan-2-yl)-2,3-dihydro-5 hydroxybenzofuran (1) and 7-chloro-2-(2-hydroxypropan-2-yl)-2,3-dihydro-5-hydroxybenzofuran (2), were obtained from the extract of the culture broth. Their structures were determined by analysis of the NMR and MS data. PMID:25973491

  17. A microfluidic device for the continuous culture and analysis of Caenorhabditis elegans in a toxic aqueous environment

    NASA Astrophysics Data System (ADS)

    Jung, Jaehoon; Nakajima, Masahiro; Tajima, Hirotaka; Huang, Qiang; Fukuda, Toshio

    2013-08-01

    The nematode Caenorhabditis elegans (C. elegans) receives attention as a bioindicator, and the C. elegans condition has been recently analyzed using microfluidic devices equipped with an imaging system. To establish a method without an imaging system, we have proposed a novel microfluidic device with which to analyze the condition of C. elegans from the capacitance change using a pair of micro-electrodes. The device was designed to culture C. elegans, to expose C. elegans to an external stimulus, such as a chemical or toxicant, and to measure the capacitance change which indicates the condition of C. elegans. In this study, to demonstrate the capability of our device in a toxic aqueous environment, the device was applied to examine the effect of cadmium on C. elegans. Thirty L4 larval stage C. elegans were divided into three groups. One group was a control group and the other groups were exposed to cadmium solutions with concentrations of 5% and 10% LC50 for 24 h. The capacitance change and the body volume of C. elegans as a reference were measured four times and we confirmed the correlation between them. It shows that our device can analyze the condition of C. elegans without an imaging system.

  18. Evaluation of fluorinated biphenyl ether pro-drug scaffolds employing the chemical-microbial approach.

    PubMed

    Hampton, Alex S; Mikulski, Lena; Palmer-Brown, William; Murphy, Cormac D; Sandford, Graham

    2016-05-01

    Incorporation of fluorine in a drug can dramatically affect its metabolism and methods to assess the effect of fluorine substitution on drug metabolism are required for effective drug design. Employing a previously developed chemical-microbial method the metabolism of a series of fluorinated biphenyl ethers was determined. The substrates were synthesized via Ullmann-type condensation reactions between bromotoluene and fluorophenol. The ethers were incubated with the fungus Cunninghamella elegans, which oxidises xenobiotics in an analogous fashion to mammals, generating a number of hydroxylated biphenyl ethers and acids. The propensity of the fluorinated ring to be hydroxylated depended upon the position of the fluorine atom, and the oxidation of the methyl group was observed when it was meta to the oxygen. The experiments demonstrate the applicability of the method to rapidly determine the effect of fluorine substitution on CYP-catalysed biotransformation of pro-drug molecules. PMID:27020303

  19. Bionectriol A, a polyketide glycoside from the fungus Bionectria sp. associated with the fungus-growing ant, Apterostigma dentigerum

    PubMed Central

    Freinkman, Elizaveta; Oh, Dong-Chan; Scott, Jarrod J.; Currie, Cameron R.; Clardy, Jon

    2009-01-01

    A new polyketide glycoside, bionectriol A (1), was produced by a fungal culture of Bionectria sp., which was isolated from a fungus garden of the fungus-growing ant Apterostigma dentigerum, in Costa Rica. The structure of bionectriol A was determined mainly through NMR and mass spectroscopic data, as well as UV and IR spectra. The relative configurations of the main chain, the pyranohexose, and the pentitol moiety were elucidated by 1H-1H coupling constants and ROESY NMR spectral analysis. PMID:20160864

  20. Anti-aging properties of Ribes fasciculatum in Caenorhabditis elegans.

    PubMed

    Jeon, Hoon; Cha, Dong Seok

    2016-05-01

    The present study investigated the effects and underlying mechanism of ethylacetate fraction of Ribes fasciculatum (ERF) on the lifespan and stress tolerance using a Caenorhabditis elegans model. The longevity activity of ERF was determined by lifespan assay under normal culture condition. The survival rate of nematodes under various stress conditions was assessed to validate the effects of ERF on the stress tolerance. To determine the antioxidant potential of ERF, the superoxide dismutase (SOD) activities and intracellular reactive oxygen species (ROS) levels were investigated. The ERF-mediated change in SOD-3 expression was examined using GFP-expressing transgenic strain. The effects of ERF on the aging-related factors were investigated by reproduction assay and pharyngeal pumping assay. The intestinal lipofuscin levels of aged nematodes were also measured. The mechanistic studies were performed using selected mutant strains. Our results indicated that ERF showed potent lifespan extension effects on the wild-type nematode under both normal and various stress conditions. The ERF treatment also enhanced the activity and expression of superoxide dismutase (SOD) and attenuated the intracellular ROS levels. Moreover, ERF-fed nematodes showed decreased lipofuscin accumulation, indicating ERF might affect age-associated changes in C. elegans. The results of mechanistic studies indicated that there was no significant lifespan extension in ERF-treated daf-2, age-1, sir-2.1, and daf-16 null mutants, suggesting that they were involved in ERF-mediated lifespan regulation. In conclusion, R. fasciculatum confers increased longevity and stress resistance in C. elegans via SIR-2.1-mediated DAF-16 activation, dependent on the insulin/IGF signaling pathway. PMID:27478096

  1. Acrylamide-responsive genes in the nematode Caenorhabditis elegans.

    PubMed

    Hasegawa, Koichi; Miwa, Satsuki; Isomura, Kazunori; Tsutsumiuchi, Kaname; Taniguchi, Hajime; Miwa, Johji

    2008-02-01

    As acrylamide is a known neurotoxin for many animals and potential carcinogen for humans, it came as a surprise when the Swedish National Food Agency and Stockholm University reported in 2002 that it is formed during the frying or baking of foods. We report here genomic and proteomic analyses on genes and proteins of Caenorhabditis elegans exposed to 500 mg/l acrylamide. Of the 21,120 genes profiled, 409 genes were more than twofold upregulated and 111 genes were downregulated. Upregulated genes included many that encode detoxification enzymes such as glutathione S-transferases (GSTs), uridine diphosphate-glucuronosyl/glucosyl transferases, and short-chain type dehydrogenases but only one cytochrome P450. Subsequent proteomic analysis confirmed the heavy involvement of GSTs. Because of their high expression levels and central roles in acrylamide metabolism, we analyzed the in vivo expression patterns of eight gst genes. Although all encoded GST and were more than twofold upregulated by acrylamide treatment, their expression patterns were varied, and their regulation involved the transcription factor SKN-1 (a C. elegans homolog of Nuclear factor E2-related factors 1 and 2). We then selected the gst-4::gfp-transformed C. elegans to study the detoxification rate of acrylamide and its metabolite glycidimide in living animals. This animal detects acrylamide as a green fluorescence protein (GFP) expression signal in a dose- and time-dependent manner and may prove to be a useful tool not only for rapidly and inexpensively detecting acrylamide, a harmful substance in food, but also for analyzing mechanisms of GST induction by acrylamide and other inducers like oxidative stresses. PMID:17989133

  2. Vampiric Isolation of Extracellular Fluid from Caenorhabditis elegans

    PubMed Central

    Banse, Stephen A.; Hunter, Craig P.

    2012-01-01

    The genetically tractable model organism C. elegans has provided insights into a myriad of biological questions, enabled by its short generation time, ease of growth and small size. This small size, though, has disallowed a number of technical approaches found in other model systems. For example, blood transfusions in mammalian systems and grafting techniques in plants enable asking questions of circulatory system composition and signaling. The circulatory system of the worm, the pseudocoelom, has until recently been impossible to assay directly. To answer questions of intercellular signaling and circulatory system composition C. elegans researchers have traditionally turned to genetic analysis, cell/tissue specific rescue, and mosaic analysis. These techniques provide a means to infer what is happening between cells, but are not universally applicable in identification and characterization of extracellular molecules. Here we present a newly developed technique to directly assay the pseudocoelomic fluid of C. elegans. The technique begins with either genetic or physical manipulation to increase the volume of extracellular fluid. Afterward the animals are subjected to a vampiric reverse microinjection technique using a microinjection rig that allows fine balance pressure control. After isolation of extracellular fluid, the collected fluid can be assayed by transfer into other animals or by molecular means. To demonstrate the effectiveness of this technique we present a detailed approach to assay a specific example of extracellular signaling molecules, long dsRNA during a systemic RNAi response. Although characterization of systemic RNAi is a proof of principle example, we see this technique as being adaptable to answer a variety of questions of circulatory system composition and signaling. PMID:22453516

  3. Vampiric isolation of extracellular fluid from Caenorhabditis elegans.

    PubMed

    Banse, Stephen A; Hunter, Craig P

    2012-01-01

    The genetically tractable model organism C. elegans has provided insights into a myriad of biological questions, enabled by its short generation time, ease of growth and small size. This small size, though, has disallowed a number of technical approaches found in other model systems. For example, blood transfusions in mammalian systems and grafting techniques in plants enable asking questions of circulatory system composition and signaling. The circulatory system of the worm, the pseudocoelom, has until recently been impossible to assay directly. To answer questions of intercellular signaling and circulatory system composition C. elegans researchers have traditionally turned to genetic analysis, cell/tissue specific rescue, and mosaic analysis. These techniques provide a means to infer what is happening between cells, but are not universally applicable in identification and characterization of extracellular molecules. Here we present a newly developed technique to directly assay the pseudocoelomic fluid of C. elegans. The technique begins with either genetic or physical manipulation to increase the volume of extracellular fluid. Afterward the animals are subjected to a vampiric reverse microinjection technique using a microinjection rig that allows fine balance pressure control. After isolation of extracellular fluid, the collected fluid can be assayed by transfer into other animals or by molecular means. To demonstrate the effectiveness of this technique we present a detailed approach to assay a specific example of extracellular signaling molecules, long dsRNA during a systemic RNAi response. Although characterization of systemic RNAi is a proof of principle example, we see this technique as being adaptable to answer a variety of questions of circulatory system composition and signaling. PMID:22453516

  4. Cas9 Variants Expand the Target Repertoire in Caenorhabditis elegans.

    PubMed

    Bell, Ryan T; Fu, Becky X H; Fire, Andrew Z

    2016-02-01

    The proliferation of CRISPR/Cas9-based methods in Caenorhabditis elegans has enabled efficient genome editing and precise genomic tethering of Cas9 fusion proteins. Experimental designs using CRISPR/Cas9 are currently limited by the need for a protospacer adjacent motif (PAM) in the target with the sequence NGG. Here we report the characterization of two modified Cas9 proteins in C. elegans that recognize NGA and NGCG PAMs. We found that each variant could stimulate homologous recombination with a donor template at multiple loci and that PAM specificity was comparable to that of wild-type Cas9. To directly compare effectiveness, we used CRISPR/Cas9 genome editing to generate a set of assay strains with a common single-guide RNA (sgRNA) target sequence, but that differ in the juxtaposed PAM (NGG, NGA, or NGCG). In this controlled setting, we determined that the NGA PAM Cas9 variant can be as effective as wild-type Cas9. We similarly edited a genomic target to study the influence of the base following the NGA PAM. Using four strains with four NGAN PAMs differing only at the fourth position and adjacent to the same sgRNA target, we observed that efficient homologous replacement was attainable with any base in the fourth position, with an NGAG PAM being the most effective. In addition to demonstrating the utility of two Cas9 mutants in C. elegans and providing reagents that permit CRISPR/Cas9 experiments with fewer restrictions on potential targets, we established a means to benchmark the efficiency of different Cas9::PAM combinations that avoids variations owing to differences in the sgRNA sequence. PMID:26680661

  5. Caenorhabditis elegans: a model to monitor bacterial air quality

    PubMed Central

    2011-01-01

    Background Low environmental air quality is a significant cause of mortality and morbidity and this question is now emerging as a main concern of governmental authorities. Airborne pollution results from the combination of chemicals, fine particles, and micro-organisms quantitatively or qualitatively dangerous for health or for the environment. Increasing regulations and limitations for outdoor air quality have been decreed in regards to chemicals and particles contrary to micro-organisms. Indeed, pertinent and reliable tests to evaluate this biohazard are scarce. In this work, our purpose was to evaluate the Caenorhaditis elegans killing test, a model considered as an equivalent to the mouse acute toxicity test in pharmaceutical industry, in order to monitor air bacterial quality. Findings The present study investigates the bacterial population in dust clouds generated during crop ship loading in harbor installations (Rouen harbor, Normandy, France). With a biocollector, airborne bacteria were impacted onto the surface of agar medium. After incubation, a replicate of the colonies on a fresh agar medium was done using a velvet. All the replicated colonies were pooled creating the "Total Air Sample". Meanwhile, all the colonies on the original plate were isolated. Among which, five representative bacterial strains were chosen. The virulence of these representatives was compared to that of the "Total Air Sample" using the Caenorhaditis elegans killing test. The survival kinetic of nematodes fed with the "Total Air Sample" is consistent with the kinetics obtained using the five different representatives strains. Conclusions Bacterial air quality can now be monitored in a one shot test using the Caenorhaditis elegans killing test. PMID:22099854

  6. Undulatory locomotion of finite filaments: lessons from Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Berman, R. S.; Kenneth, O.; Sznitman, J.; Leshansky, A. M.

    2013-07-01

    Undulatory swimming is a widespread propulsion strategy adopted by many small-scale organisms including various single-cell eukaryotes and nematodes. In this work, we report a comprehensive study of undulatory locomotion of a finite filament using (i) approximate resistive force theory (RFT) assuming a local nature of hydrodynamic interaction between the filament and the surrounding viscous liquid and (ii) particle-based numerical computations taking into account the intra-filament hydrodynamic interaction. Using the ubiquitous model of a propagating sinusoidal waveform, we identify the limit of applicability of the RFT and determine the optimal propulsion gait in terms of (i) swimming distance per period of undulation and (ii) hydrodynamic propulsion efficiency. The occurrence of the optimal swimming gait maximizing hydrodynamic efficiency at finite wavelength in particle-based computations diverges from the prediction of the RFT. To compare the model swimmer powered by sine wave undulations to biological undulatory swimmers, we apply the particle-based approach to study locomotion of the model organism nematode Caenorhabditis elegans using the swimming gait extracted from experiments. The analysis reveals that even though the amplitude and the wavenumber of undulations are similar to those determined for the best performing sinusoidal swimmer, C. elegans overperforms the latter in terms of both displacement and hydrodynamic efficiency. Further comparison with other undulatory microorganisms reveals that many adopt waveforms with characteristics similar to the optimal model swimmer, yet real swimmers still manage to beat the best performing sine-wave swimmer in terms of distance covered per period. Overall our results underline the importance of further waveform optimization, as periodic undulations adopted by C. elegans and other organisms deviate considerably from a simple sine wave.

  7. Global remodeling of nucleosome positions in C. elegans

    PubMed Central

    2013-01-01

    Background Eukaryotic chromatin architecture is affected by intrinsic histone-DNA sequence preferences, steric exclusion between nucleosome particles, formation of higher-order structures, and in vivo activity of chromatin remodeling enzymes. Results To disentangle sequence-dependent nucleosome positioning from the other factors, we have created two high-throughput maps of nucleosomes assembled in vitro on genomic DNA from the nematode worm Caenorhabditis elegans. A comparison of in vitro nucleosome positions with those observed in a mixed-stage, mixed-tissue population of C. elegans cells reveals that in vivo sequence preferences are modified on the genomic scale. Indeed, G/C dinucleotides are predicted to be most favorable for nucleosome formation in vitro but not in vivo. Nucleosome sequence read coverage in vivo is distinctly lower in chromosome arms than in central regions; the observed changes in apparent nucleosome sequence specificity, likely due to genome-wide chromatin remodeler activity, contribute to the formation of these megabase-scale chromatin domains. We also observe that the majority of well-positioned in vivo nucleosomes do not occupy thermodynamically favorable sequences observed in vitro. Finally, we find that exons are intrinsically more amenable to nucleosome formation compared to introns. Nucleosome occupancy of introns and exons consistently increases with G/C content in vitro but not in vivo, in agreement with our observation that G/C dinucleotide enrichment does not strongly promote in vivo nucleosome formation. Conclusions Our findings highlight the importance of both sequence specificity and active nucleosome repositioning in creating large-scale chromatin domains, and the antagonistic roles of intrinsic sequence preferences and chromatin remodelers in C. elegans. Sequence read data has been deposited into Sequence Read Archive (http://www.ncbi.nlm.nih.gov/sra; accession number SRA050182). Additional data, software and computational

  8. Structural Properties of the Caenorhabditis elegans Neuronal Network

    PubMed Central

    Varshney, Lav R.; Chen, Beth L.; Paniagua, Eric; Hall, David H.; Chklovskii, Dmitri B.

    2011-01-01

    Despite recent interest in reconstructing neuronal networks, complete wiring diagrams on the level of individual synapses remain scarce and the insights into function they can provide remain unclear. Even for Caenorhabditis elegans, whose neuronal network is relatively small and stereotypical from animal to animal, published wiring diagrams are neither accurate nor complete and self-consistent. Using materials from White et al. and new electron micrographs we assemble whole, self-consistent gap junction and chemical synapse networks of hermaphrodite C. elegans. We propose a method to visualize the wiring diagram, which reflects network signal flow. We calculate statistical and topological properties of the network, such as degree distributions, synaptic multiplicities, and small-world properties, that help in understanding network signal propagation. We identify neurons that may play central roles in information processing, and network motifs that could serve as functional modules of the network. We explore propagation of neuronal activity in response to sensory or artificial stimulation using linear systems theory and find several activity patterns that could serve as substrates of previously described behaviors. Finally, we analyze the interaction between the gap junction and the chemical synapse networks. Since several statistical properties of the C. elegans network, such as multiplicity and motif distributions are similar to those found in mammalian neocortex, they likely point to general principles of neuronal networks. The wiring diagram reported here can help in understanding the mechanistic basis of behavior by generating predictions about future experiments involving genetic perturbations, laser ablations, or monitoring propagation of neuronal activity in response to stimulation. PMID:21304930

  9. ICeE an interface for C. elegans experiments

    PubMed Central

    Montañana, Frédéric; Julien, Renaud A; Vaglio, Philippe; Matthews, Lisa R; Tichit, Laurent; Ewbank, Jonathan J

    2014-01-01

    An increasing number of laboratories are using the COPAS Biosort™ to implement high-throughput approaches to tackle diverse biological problems. While providing a powerful tool for generating quantitative data, the utility of the Biosort is currently limited by the absence of resources for data management. We describe a simple electronic database designed to allow easy storage and retrieval of Biosort data for C. elegans, but that has a wide potential application for organizing electronic files and data sets. ICeE is an Open Source application. The code and accompanying documentation are freely available via the web at http://www.ciml.univ-mrs.fr/EWBANK_jonathan/software.html. PMID:26430546

  10. Soft X-ray contact microscopy of nematode Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Poletti, G.; Orsini, F.; Batani, D.; Bernardinello, A.; Desai, T.; Ullschmied, J.; Skala, J.; Kralikova, B.; Krousky, E.; Juha, L.; Pfeifer, M.; Kadlec, Ch.; Mocek, T.; Präg, A.; Renner, O.; Cotelli, F.; Lora Lamia, C.; Zullini, A.

    2004-08-01

    Soft X-ray Contact Microscopy (SXCM) of Caenorhabditis elegans nematodes with typical length ~800 μ m and diameter ~30 μ m has been performed using the PALS laser source of wavelength λ = 1.314~μ m and pulse duration τ (FWHM) = 400 ps. Pulsed soft X-rays were generated using molybdenum and gold targets with laser intensities I ≥ 1014 W/cm2. Images have been recorded on PMMA photo resists and analyzed using an atomic force microscope operating in contact mode. Cuticle features and several internal organs have been identified in the SXCM images including lateral field, cuticle annuli, pharynx, and hypodermal and neuronal cell nuclei.

  11. Caenorhabditis elegans - A model system for space biology studies

    NASA Technical Reports Server (NTRS)

    Johnson, Thomas E.; Nelson, Gregory A.

    1991-01-01

    The utility of the nematode Caenorhabditis elegans in studies spanning aspects of development, aging, and radiobiology is reviewed. These topics are interrelated via cellular and DNA repair processes especially in the context of oxidative stress and free-radical metabolism. The relevance of these research topics to problems in space biology is discussed and properties of the space environment are outlined. Exposure to the space-flight environment can induce rapid changes in living systems that are similar to changes occurring during aging; manipulation of these environmental parameters may represent an experimental strategy for studies of development and senescence. The current and future opportunities for such space-flight experimentation are presented.

  12. Google matrix analysis of C.elegans neural network

    NASA Astrophysics Data System (ADS)

    Kandiah, V.; Shepelyansky, D. L.

    2014-05-01

    We study the structural properties of the neural network of the C.elegans (worm) from a directed graph point of view. The Google matrix analysis is used to characterize the neuron connectivity structure and node classifications are discussed and compared with physiological properties of the cells. Our results are obtained by a proper definition of neural directed network and subsequent eigenvector analysis which recovers some results of previous studies. Our analysis highlights particular sets of important neurons constituting the core of the neural system. The applications of PageRank, CheiRank and ImpactRank to characterization of interdependency of neurons are discussed.

  13. Mortality Rates in a Genetically Heterogeneous Population of Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Brooks, Anne; Lithgow, Gordon J.; Johnson, Thomas E.

    1994-02-01

    Age-specific mortality rates in isogenic populations of the nematode Caenorhabditis elegans increase exponentially throughout life. In genetically heterogeneous populations, age-specific mortality increases exponentially until about 17 days and then remains constant until the last death occurs at about 60 days. This period of constant age-specific mortality results from genetic heterogeneity. Subpopulations differ in mean life-span, but they all exhibit near exponential, albeit different, rates of increase in age-specific mortality. Thus, much of the observed heterogeneity in mortality rates later in life could result from genetic heterogeneity and not from an inherent effect of aging.

  14. Immune defense mechanisms in the Caenorhabditis elegans intestinal epithelium

    PubMed Central

    Pukkila-Worley, Read; Ausubel, Frederick M

    2013-01-01

    Intestinal epithelial cells provide an essential line of defense for Caenorhabditis elegans against ingested pathogens. Because nematodes consume microorganisms as their food source, there has presumably been selection pressure to evolve and maintain immune defense mechanisms within the intestinal epithelium. Here we review recent advances that further define the immune signaling network within these cells and suggest mechanisms used by the nematode to monitor for infection. In reviewing studies of pathogenesis that use this simple model system, we hope to illustrate some of the basic principles of epithelial immunity that may also be of relevance in higher order hosts. PMID:22236697

  15. Scratching the Niche That Controls C. elegans Germline Stem Cells

    PubMed Central

    Byrd, Dana T.; Kimble, Judith

    2010-01-01

    The C. elegans gonad provides a well-defined model for a stem cell niche and its control of self-renewal and differentiation. The distal tip cell (DTC) forms a mesenchymal niche that controls germline stem cells (GSCs), both to generate the germline tissue during development and to maintain it during adulthood. The DTC uses GLP-1/Notch signaling to regulate GSCs; germ cells respond to Notch signaling with a network of RNA regulators to control the decision between self-renewal and entry into the meiotic cell cycle. PMID:19765664

  16. ICeE an interface for C. elegans experiments.

    PubMed

    Montañana, Frédéric; Julien, Renaud A; Vaglio, Philippe; Matthews, Lisa R; Tichit, Laurent; Ewbank, Jonathan J

    2014-01-01

    An increasing number of laboratories are using the COPAS Biosort™ to implement high-throughput approaches to tackle diverse biological problems. While providing a powerful tool for generating quantitative data, the utility of the Biosort is currently limited by the absence of resources for data management. We describe a simple electronic database designed to allow easy storage and retrieval of Biosort data for C. elegans, but that has a wide potential application for organizing electronic files and data sets. ICeE is an Open Source application. The code and accompanying documentation are freely available via the web at http://www.ciml.univ-mrs.fr/EWBANK_jonathan/software.html. PMID:26430546

  17. C. elegans Metabolic Gene Regulatory Networks Govern the Cellular Economy

    PubMed Central

    Watson, Emma; Walhout, Albertha J.M.

    2014-01-01

    Diet greatly impacts metabolism in health and disease. In response to the presence or absence of specific nutrients, metabolic gene regulatory networks sense the metabolic state of the cell and regulate metabolic flux accordingly, for instance by the transcriptional control of metabolic enzymes. Here we discuss recent insights regarding metazoan metabolic regulatory networks using the nematode Caenorhabditis elegans as a model, including the modular organization of metabolic gene regulatory networks, the prominent impact of diet on the transcriptome and metabolome, specialized roles of nuclear hormone receptors in responding to dietary conditions, regulation of metabolic genes and metabolic regulators by microRNAs, and feedback between metabolic genes and their regulators. PMID:24731597

  18. Apophysomyces elegans causing acute otogenic cervicofacial zygomycosis involving salivary glands.

    PubMed

    Goyal, Amit; Tyagi, Isha; Syal, Rajan; Marak, R S K; Singh, Jagdeep

    2007-08-01

    Zygomycosis is an invasive, life threatening fungal infection that usually affects immunocompromised hosts. In the head and neck region, rhino-orbito-cerebral zygomycosis is more common than the cervicofacial variety. We report the first case of otogenic cervicofacial zygomycosis caused by Apophysomyces elegans involving the salivary glands, an uncommon site of infection. The case began after a trivial trauma in a diabetic patient and despite surgical debridement and liposomal amphotericin B therapy, the patient died due to extensive involvement and metabolic/hemodynamic complications. PMID:17654273

  19. Positioning of longitudinal nerves in C. elegans by nidogen.

    PubMed

    Kim, S; Wadsworth, W G

    2000-04-01

    Basement membranes can help determine pathways of migrating axons. Although members of the nidogen (entactin) protein family are structural components of basement membranes, we find that nidogen is not required for basement membrane assembly in the nematode Caenorhabditis elegans. Nidogen is localized to body wall basement membranes and is required to direct longitudinal nerves dorsoventrally and to direct axons at the midlines. By examining migration of a single axon in vivo, we show that nidogen is required for the axon to switch from circumferential to longitudinal migration. Specialized basement membranes may thus regulate nerve position. PMID:10753123

  20. Fun Microbiology: How To Measure Growth of a Fungus.

    ERIC Educational Resources Information Center

    Mitchell, James K.; And Others

    1997-01-01

    Describes an experiment to demonstrate a simple method for measuring fungus growth by monitoring the effect of temperature on the growth of Trichoderma viride. Among the advantages that this experimental model provides is introducing students to the importance of using the computer as a scientific tool for analyzing and presenting data. (AIM)

  1. PESTALOTIOPSIS MACULANS IS A PARASYMBIONTIC FUNGUS IN NORTH AMERICAN LICHENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    By culturing small thallus portions in nutrient medium, it could be shown that Pestalotiopisis maculans (Corda) Nag Raj is a dominant parasymbiontic fungus in North American lichens. P. maculans was present in all twelve lichen specimens (10 Cladina, 1 Usnea, and 1 Parmetroma) collected in the east...

  2. OXIDATIVE DEGRADATION OF PHENANTHRENE BY THE LIGNINOLYTIC FUNGUS PHANEROCHAETE CHRYSOSPORIUM

    EPA Science Inventory

    The ligninolytic fungus Phanerochaete chrysosporium oxidized phenanthrene and phenanthrene-9,10-quinone (PQ) at their C-9 and C-10 positions to give a ring-fission product, 2,2'-diphenic acid (DPA), which was identified in chromatographic and isotope dilution experiments. PA form...

  3. Controlling fungus on channel catfish eggs with peracetic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is much interest in the use of peracetic acid (PAA) to treat pathogens in aquaculture. It is a relatively new compound and is approved for use in Europe, but not in the United States. This study determined the effectiveness of PAA for fungus control on channel catfish Ictalurus punctatus egg...

  4. Directed Evolution of a Filamentous Fungus for Thermotolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Filamentous fungi represent the most widely used eukaryotic biocatalysts in industrial and chemical applications. Metarhizium anisopliae is a broad-host-range entomopathogenic fungus currently under intensive investigation as a biologically based alternative to chemical pesticides. One of the most p...

  5. Using copper sulfate to control fungus on fish eggs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper sulfate (CuSO4) is widely used by the catfish industry as an economical treatment to control fungus (Saprolegnia spp.) on catfish eggs. This is an overview of our effectiveness and safety studies. Channel catfish spawns were 24 - 48 hrs old. Comparable portions of a single spawn were place...

  6. Analysis of a Functional Lactate Permease in the Fungus Rhizopus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Rhizopus is frequently used for fermentative production of lactic acid, but little is known about the mechanisms or proteins for transporting this carboxylic acid. Since transport of the lactate anion across the plasma membrane is critical to prevent acidification of the cytoplasm, we ev...

  7. Inferring dispersal patterns of the generalist root fungus Armillaria mellea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Investigating the dispersal of the root-pathogenic fungus Armillaria mellea is necessary to understand its population biology. Such an investigation is complicated by both its subterranean habit and the persistence of genotypes over successive host generations. As such, host colonization by resident...

  8. OXIDATION OF PERSISTANT ENVIRONMENTAL POLLUTANTS BY A WHITE ROT FUNGUS

    EPA Science Inventory

    The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene t...

  9. Genetic variability in the pistachio late blight fungus, Alternaria alternata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic variation in the pistachio late blight fungus, Alternaria alternata, was investigated by restriction fragment length polymorphism (RFLP) in the rDNA region. Southern hybridization of EcoRI, HindIII, and Xbal digested fungal DNA with a RNA probe derived from Alt1, an rDNA clone isolated from ...

  10. Draft Genome Sequence of the Fungus Trametes hirsuta 072

    PubMed Central

    Tyazhelova, Tatiana V.; Moiseenko, Konstantin V.; Vasina, Daria V.; Mosunova, Olga V.; Fedorova, Tatiana V.; Maloshenok, Lilya G.; Landesman, Elena O.; Bruskin, Sergei A.; Psurtseva, Nadezhda V.; Slesarev, Alexei I.; Kozyavkin, Sergei A.; Koroleva, Olga V.

    2015-01-01

    A standard draft genome sequence of the white rot saprotrophic fungus Trametes hirsuta 072 (Basidiomycota, Polyporales) is presented. The genome sequence contains about 33.6 Mb assembled in 141 scaffolds with a G+C content of ~57.6%. The draft genome annotation predicts 14,598 putative protein-coding open reading frames (ORFs). PMID:26586872

  11. The development and endophytic nature of the fungus Heteroconium chaetospira.

    PubMed

    Hashiba, Teruyoshi; Narisawa, Kazuhiko

    2005-11-15

    The root endophytic fungus Heteroconium chaetospira was isolated from roots of Chinese cabbage grown in field soil in Japan. This fungus penetrates through the outer epidermal cells of its host, passes into the inner cortex, and grows throughout the cortical cells, including those of the root tip region, without causing apparent pathogenic symptoms. There are no ultrastructural signs of host resistance responses. H. chaetospira has been recovered from 19 plant species in which there was no disruption of host growth. H. chaetospira has a symbiotic association with Chinese cabbage. The fungus provides nitrogen in exchange for carbon. These associations are beneficial for the inoculated plants, as demonstrated by increased growth rate. When used as a preinoculum, H. chaetospira suppresses the incidence of clubroot and Verticillium yellows when the test plant is post-inoculated with the causal agents of these diseases. H. chaetospira is an effective biocontrol agent against clubroot in Chinese cabbage at a low to moderate soil moisture range and a pathogen resting spore density of 10(5) resting spores per gram of soil in situ. Disease caused by Pseudomonas syringae pv. macricola and Alternaria brassicae on leaves can be suppressed by treatment with H. chaetospira. The fungus persists in the roots and induces systemic resistance to the foliar disease. PMID:16168582

  12. Characterization of a basidiomycete fungus from sugarbeet in Idaho

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A fungus of unknown etiology was observed on stored sugarbeet roots exhibiting signs of white cottony growth in 2006 and 2007 in Idaho. Eighteen isolates obtained from sugarbeet roots were examined for growth characteristics on nutrient medium, production of phenol oxidases and ITS rDNA sequence. On...

  13. On-farm Production and Utilization of AM Fungus Inoculum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On-farm production of arbuscular mycorrhizal [AM] fungus inoculum can make the benefits to crop growth and yield of inoculation with AM fungi available to more farmers by reducing costs. This article details the step by step procedure and management decisions that are needed for the on-farm product...

  14. A new polyoxygenated farnesylcyclohexenone from Fungus Penicillium sp.

    PubMed

    Yang, Yabin; Yang, Fangfang; Zhao, Lixing; Duang, Rongting; Chen, Guangyi; Li, Xiaozhan; Li, Qiling; Qin, Shaohuan; Ding, Zhongtao

    2016-01-01

    A new polyoxygenated farnesylcyclohexenone, peniginsengin A (1), was isolated from the fermentation of Penicillium sp. YIM PH30003, an endophytic fungus associated with Panax notoginseng (Burk.) F. H. Chen. The structure was assigned based on a combination of 1 D and 2 D NMR and mass spectral data. The cytotoxicity and antimicrobial activities of compound 1 were investigated. PMID:25906789

  15. Microsatellites from the charcoal rot fungus (Macrophomina phaseolina)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microsatellite loci were identified from the charcoal rot fungus Macrophomina phaseolina. Primer pairs for 46 loci were developed and of these 13 were optimized and screened using genomic DNA from 44 fungal isolates collected predominantly from two soybean fields in MS. All optimized loci were poly...

  16. A Brazilian social bee must cultivate fungus to survive.

    PubMed

    Menezes, Cristiano; Vollet-Neto, Ayrton; Marsaioli, Anita Jocelyne; Zampieri, Davila; Fontoura, Isabela Cardoso; Luchessi, Augusto Ducati; Imperatriz-Fonseca, Vera Lucia

    2015-11-01

    The nests of social insects provide suitable microenvironments for many microorganisms as they offer stable environmental conditions and a rich source of food [1-4]. Microorganisms in turn may provide several benefits to their hosts, such as nutrients and protection against pathogens [1, 4-6]. Several examples of symbiosis between social insects and microorganisms have been found in ants and termites. These symbioses have driven the evolution of complex behaviors and nest structures associated with the culturing of the symbiotic microorganisms [5, 7, 8]. However, while much is known about these relationships in many species of ants and termites, symbiotic relationships between microorganisms and social bees have been poorly explored [3, 4, 9, 10]. Here, we report the first case of an obligatory relationship between the Brazilian stingless bee Scaptotrigona depilis and a fungus of the genus Monascus (Ascomycotina). Fungal mycelia growing on the provisioned food inside the brood cell are eaten by the larva. Larvae reared in vitro on sterilized larval food supplemented with fungal mycelia had a much higher survival rate (76%) compared to larvae reared under identical conditions but without fungal mycelia (8% survival). The fungus was found to originate from the material from which the brood cells are made. Since the bees recycle and transport this material between nests, fungus would be transferred to newly built cells and also to newly founded nests. This is the first report of a fungus cultivation mutualism in a social bee. PMID:26592344

  17. Evolutionary patterns of proteinase activity in attine ant fungus gardens

    PubMed Central

    2011-01-01

    Background Attine ants live in symbiosis with a basidiomycetous fungus that they rear on a substrate of plant material. This indirect herbivory implies that the symbiosis is likely to be nitrogen deprived, so that specific mechanisms may have evolved to enhance protein availability. We therefore hypothesized that fungal proteinase activity may have been under selection for efficiency and that different classes of proteinases might be involved. Results We determined proteinase activity profiles across a wide pH range for fungus gardens of 14 Panamanian species of fungus-growing ants, representing eight genera. We mapped these activity profiles on an independently obtained molecular phylogeny of the symbionts and show that total proteinase activity in lower attine symbionts peaks at ca. pH 6. The higher attine symbionts that have no known free-living relatives had much higher proteinase activities than the lower attine symbionts. Their total in vitro proteinase activity peaked at pH values around 5, which is close to the pH that the ants maintain in their fungus gardens, suggesting that the pH optimum of fungal proteinases may have changed after the irreversible domestication of evolutionary more derived fungal symbionts. This notion is also supported by buffering capacities of fungus gardens at pH 5.2 being remarkably high, and suggests that the fungal symbiont actively helps to maintain garden acidity at this specific level. Metalloproteinases dominated the activity profiles of lower attine gardens and may thus represent the ancestral type of proteinase production, whereas serine proteinase activity dominated the activity profiles of the higher attine gardens reared by Trachymyrmex and Sericomyrmex, suggesting that there may be trade-offs in the production of these enzyme classes. Remarkably, the single symbiont that is shared by species of the crown group of Atta and Acromyrmex leaf-cutting ants mostly showed metalloproteinase activity, suggesting that recurrent

  18. Dialogue between E. coli free radical pathways and the mitochondria of C. elegans

    PubMed Central

    Govindan, J. Amaranath; Jayamani, Elamparithi; Zhang, Xinrui; Mylonakis, Eleftherios; Ruvkun, Gary

    2015-01-01

    The microbial world presents a complex palette of opportunities and dangers to animals, which have developed surveillance and response strategies to hints of microbial intent. We show here that the mitochondrial homeostatic response pathway of the nematode Caenorhabditis elegans responds to Escherichia coli mutations that activate free radical detoxification pathways. Activation of C. elegans mitochondrial responses could be suppressed by additional mutations in E. coli, suggesting that C. elegans responds to products of E. coli to anticipate challenges to its mitochondrion. Out of 50 C. elegans gene inactivations known to mediate mitochondrial defense, we found that 7 genes were required for C. elegans response to a free radical producing E. coli mutant, including the bZip transcription factor atfs-1 (activating transcription factor associated with stress). An atfs-1 loss-of-function mutant was partially resistant to the effects of free radical-producing E. coli mutant, but a constitutively active atfs-1 mutant growing on wild-type E. coli inappropriately activated the pattern of mitochondrial responses normally induced by an E. coli free radical pathway mutant. Carbonylated proteins from free radical-producing E. coli mutant may directly activate the ATFS-1/bZIP transcription factor to induce mitochondrial stress response: feeding C. elegans with H2O2-treated E. coli induces the mitochondrial unfolded protein response, and inhibition of a gut peptide transporter partially suppressed C. elegans response to free radical damaged E. coli. PMID:26392561

  19. Elucidating the Mechanism of Weissella-dependent Lifespan Extension in Caenorhabditis elegans

    PubMed Central

    Lee, Jiyun; Kwon, Gayeung; Lim, Young-Hee

    2015-01-01

    The mechanism whereby lactic acid bacteria extend the lifespan of Caenorhabditis elegans has previously been elucidated. However, the role of Weissella species has yet not been studied. We show that Weissella koreensis and Weissella cibaria significantly (p < 0.05) extend the lifespan of C. elegans compared with Escherichia coli OP50 and induce the expression of several genes related to lifespan extension (daf-16, aak-2, jnk-1, sod-3 and hif-1). Oral administration of Weissella altered reactive oxygen species (ROS) production and lowered the accumulation of lipofuscin and increased locomotor activity (which translates to a delay in ageing). Moreover, Weissella-fed C. elegans had decreased body sizes, brood sizes, ATP levels and pharyngeal pumping rates compared with E. coli OP50-fed worms. Furthermore, mutations in sod-3, hif-1 or skn-1 did not alter lifespan extension compared with wild-type C. elegans. However, C. elegans failed to display lifespan extension in loss-of-function mutants of daf-16, aak-2 and jnk-1, which highlights the potential role of these genes in Weissella-induced longevity in C. elegans. Weissella species extend C. elegans lifespan by activating DAF-16 via the c-Jun N-terminal kinase (JNK) pathway, which is related to stress response, and the AMP-activated protein kinase (AMPK)-pathway that is activated by dietary restriction. PMID:26601690

  20. Computer-Assisted Transgenesis of Caenorhabditis elegans for Deep Phenotyping.

    PubMed

    Gilleland, Cody L; Falls, Adam T; Noraky, James; Heiman, Maxwell G; Yanik, Mehmet F

    2015-09-01

    A major goal in the study of human diseases is to assign functions to genes or genetic variants. The model organism Caenorhabditis elegans provides a powerful tool because homologs of many human genes are identifiable, and large collections of genetic vectors and mutant strains are available. However, the delivery of such vector libraries into mutant strains remains a long-standing experimental bottleneck for phenotypic analysis. Here, we present a computer-assisted microinjection platform to streamline the production of transgenic C. elegans with multiple vectors for deep phenotyping. Briefly, animals are immobilized in a temperature-sensitive hydrogel using a standard multiwell platform. Microinjections are then performed under control of an automated microscope using precision robotics driven by customized computer vision algorithms. We demonstrate utility by phenotyping the morphology of 12 neuronal classes in six mutant backgrounds using combinations of neuron-type-specific fluorescent reporters. This technology can industrialize the assignment of in vivo gene function by enabling large-scale transgenic engineering. PMID:26163188

  1. Genetics of Lipid-Storage Management in Caenorhabditis elegans Embryos.

    PubMed

    Schmökel, Verena; Memar, Nadin; Wiekenberg, Anne; Trotzmüller, Martin; Schnabel, Ralf; Döring, Frank

    2016-03-01

    Lipids play a pivotal role in embryogenesis as structural components of cellular membranes, as a source of energy, and as signaling molecules. On the basis of a collection of temperature-sensitive embryonic lethal mutants, a systematic database search, and a subsequent microscopic analysis of >300 interference RNA (RNAi)-treated/mutant worms, we identified a couple of evolutionary conserved genes associated with lipid storage in Caenorhabditis elegans embryos. The genes include cpl-1 (cathepsin L-like cysteine protease), ccz-1 (guanine nucleotide exchange factor subunit), and asm-3 (acid sphingomyelinase), which is closely related to the human Niemann-Pick disease-causing gene SMPD1. The respective mutant embryos accumulate enlarged droplets of neutral lipids (cpl-1) and yolk-containing lipid droplets (ccz-1) or have larger genuine lipid droplets (asm-3). The asm-3 mutant embryos additionally showed an enhanced resistance against C band ultraviolet (UV-C) light. Herein we propose that cpl-1, ccz-1, and asm-3 are genes required for the processing of lipid-containing droplets in C. elegans embryos. Owing to the high levels of conservation, the identified genes are also useful in studies of embryonic lipid storage in other organisms. PMID:26773047

  2. Anabolic function of phenylalanine hydroxylase in Caenorhabditis elegans.

    PubMed

    Calvo, Ana C; Pey, Angel L; Ying, Ming; Loer, Curtis M; Martinez, Aurora

    2008-08-01

    In humans, liver phenylalanine hydroxylase (PAH) has an established catabolic function, and mutations in PAH cause phenylketonuria, a genetic disease characterized by neurological damage, if not treated. To obtain novel evolutionary insights and information on molecular mechanisms operating in phenylketonuria, we investigated PAH in the nematode Caenorhabditis elegans (cePAH), where the enzyme is coded by the pah-1 gene, expressed in the hypodermis. CePAH presents similar molecular and kinetic properties to human PAH [S(0.5)(L-Phe) approximately 150 microM; K(m) for tetrahydrobiopterin (BH(4)) approximately 35 microM and comparable V(max)], but cePAH is devoid of positive cooperativity for L-Phe, an important regulatory mechanism of mammalian PAH that protects the nervous system from excess L-Phe. Pah-1 knockout worms show no obvious neurological defects, but in combination with a second cuticle synthesis mutation, they display serious cuticle abnormalities. We found that pah-1 knockouts lack a yellow-orange pigment in the cuticle, identified as melanin by spectroscopic techniques, and which is detected in C. elegans for the first time. Pah-1 mutants show stimulation of superoxide dismutase activity, suggesting that cuticle melanin functions as oxygen radical scavenger. Our results uncover both an important anabolic function of PAH and the change in regulation of the enzyme along evolution. PMID:18460651

  3. Phenazine derivatives cause proteotoxicity and stress in C. elegans

    PubMed Central

    Ray, Arpita; Rentas, Courtney; Caldwell, Guy A.; Caldwell, Kim A.

    2014-01-01

    It is widely recognized that bacterial metabolites have toxic effects in animal systems. Phenazines are a common bacterial metabolite within the redox-active exotoxin class. These compounds have been shown to be toxic to the soil invertebrate Caenorhabditis elegans with the capability of causing oxidative stress and lethality. Here we report that chronic, low-level exposure to three separate phenazine molecules (phenazine-1-carboxylic acid, pyocyanin and 1-hydroxyphenazine) upregulated ER stress response and enhanced expression of a superoxide dismutase reporter in vivo. Exposure to these molecules also increased of polyglutamine and α-synuclein in the bodywall muscle cells of C. elegans. Exposure of worms to these phenazines caused additional sensitivity in dopamine neurons expressing wild-type α-synuclein, indicating a possible defect in protein homeostasis. The addition of an anti-oxidant failed to rescue the neurotoxic and protein aggregation phenotypes caused by these compounds. Thus, increased production of superoxide radicals that occurs in whole animals in response to these phenazines appears independent from the toxicity phenotype observed. Collectively, these data provide cause for further consideration of the neurodegenerative impact of phenazines. PMID:25304539

  4. Computer-Assisted Transgenesis of Caenorhabditis elegans for Deep Phenotyping

    PubMed Central

    Gilleland, Cody L.; Falls, Adam T.; Noraky, James; Heiman, Maxwell G.; Yanik, Mehmet F.

    2015-01-01

    A major goal in the study of human diseases is to assign functions to genes or genetic variants. The model organism Caenorhabditis elegans provides a powerful tool because homologs of many human genes are identifiable, and large collections of genetic vectors and mutant strains are available. However, the delivery of such vector libraries into mutant strains remains a long-standing experimental bottleneck for phenotypic analysis. Here, we present a computer-assisted microinjection platform to streamline the production of transgenic C. elegans with multiple vectors for deep phenotyping. Briefly, animals are immobilized in a temperature-sensitive hydrogel using a standard multiwell platform. Microinjections are then performed under control of an automated microscope using precision robotics driven by customized computer vision algorithms. We demonstrate utility by phenotyping the morphology of 12 neuronal classes in six mutant backgrounds using combinations of neuron-type-specific fluorescent reporters. This technology can industrialize the assignment of in vivo gene function by enabling large-scale transgenic engineering. PMID:26163188

  5. Left-right patterning in the C. elegans embryo

    PubMed Central

    2011-01-01

    The development of bilateral symmetry during the evolution of species probably 600 million years ago brought about several important innovations: It fostered efficient locomotion, streamlining and favored the development of a central nervous system through cephalization. However, to increase their functional capacities, many organisms exhibit chirality by breaking their superficial left-right (l-r) symmetry, which manifests in the lateralization of the nervous system or the l-r asymmetry of internal organs. In most bilateria, the mechanisms that maintain consistent l-r asymmetry throughout development are poorly understood. This review highlights insights into mechanisms that couple early embryonic l-r symmetry breaking to subsequent l-r patterning in the roundworm Caenorhabditis elegans. A recently identified strategy for l-r patterning in the early C. elegans embryo is discussed, the spatial separation of midline and anteroposterior axis, which relies on a rotational cellular rearrangement and non-canonical Wnt signaling. Evidence for a general relevance of rotational/torsional rearrangements during organismal l-r patterning and for non-canonical Wnt signaling/planar cell polarity as a common signaling mechanism to maintain l-r asymmetry is presented. PMID:21509174

  6. No reduction of metabolic rate in food restricted Caenorhabditis elegans.

    PubMed

    Houthoofd, Koen; Braeckman, Bart P; Lenaerts, Isabelle; Brys, Kristel; De Vreese, Annemie; Van Eygen, Sylvie; Vanfleteren, Jacques R

    2002-12-01

    Dietary restriction (DR) is the most consistent means of extending life span throughout the animal kingdom. Multiple mechanisms by which DR may act have been proposed but none are clearly predominant. We asked whether metabolic rate and stress resistance is altered in Caenorhabditis elegans in response to DR. DR was imposed in two complementary ways: by growing wild-type worms in liquid medium supplemented with reduced concentrations of bacteria and by using eat-2 mutants, which have a feeding defect. Metabolic rate was not reduced when we fed wild-type worms reduced food and was up-regulated in the eat-2 mutants in liquid culture, as assessed by oxygen consumption rate and heat production. The specific activity levels of the antioxidant enzymes superoxide dismutase (SOD) and catalase showed small increases when we reduced food in wild-type worms, but restricted worms acquired no elevated protection against paraquat and hydrogen peroxide. eat-2 mutants showed elevated specific activities of SOD and catalase relative to wild type in liquid culture. These results indicate that the effects imparted by DR and the eat-2 mutation are not identical, and they contradict, at least in C. elegans, the widespread belief that CR acts by lowering the rate of metabolism. PMID:12559405

  7. Mitoflash frequency in early adulthood predicts lifespan in Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Shen, En-Zhi; Song, Chun-Qing; Lin, Yuan; Zhang, Wen-Hong; Su, Pei-Fang; Liu, Wen-Yuan; Zhang, Pan; Xu, Jiejia; Lin, Na; Zhan, Cheng; Wang, Xianhua; Shyr, Yu; Cheng, Heping; Dong, Meng-Qiu

    2014-04-01

    It has been theorized for decades that mitochondria act as the biological clock of ageing, but the evidence is incomplete. Here we show a strong coupling between mitochondrial function and ageing by in vivo visualization of the mitochondrial flash (mitoflash), a frequency-coded optical readout reflecting free-radical production and energy metabolism at the single-mitochondrion level. Mitoflash activity in Caenorhabditis elegans pharyngeal muscles peaked on adult day 3 during active reproduction and on day 9 when animals started to die off. A plethora of genetic mutations and environmental factors inversely modified the lifespan and the day-3 mitoflash frequency. Even within an isogenic population, the day-3 mitoflash frequency was negatively correlated with the lifespan of individual animals. Furthermore, enhanced activity of the glyoxylate cycle contributed to the decreased day-3 mitoflash frequency and the longevity of daf-2 mutant animals. These results demonstrate that the day-3 mitoflash frequency is a powerful predictor of C. elegans lifespan across genetic, environmental and stochastic factors. They also support the notion that the rate of ageing, although adjustable in later life, has been set to a considerable degree before reproduction ceases.

  8. Fat Metabolism Regulates Satiety Behavior in C. elegans

    PubMed Central

    Hyun, Moonjung; Davis, Kristen; Lee, Inhwan; Kim, Jeongho; Dumur, Catherine; You, Young-Jai

    2016-01-01

    Animals change feeding behavior depending on their metabolic status; starved animals are eager to eat and satiated animals stop eating. C. elegans exhibits satiety quiescence under certain conditions that mimics many aspects of post-prandial sleep in mammals. Here we show that this feeding behavior depends on fat metabolism mediated by the SREBP-SCD pathway, an acetyl-CoA carboxylase (ACC) and certain nuclear hormone receptors (NRs). Mutations of the genes in the SREBP-SCD pathway reduce satiety quiescence. An RNA interference (RNAi) screen of the genes that regulate glucose and fatty acid metabolism identified an ACC necessary for satiety quiescence in C. elegans. ACC catalyzes the first step in de novo fatty acid biosynthesis known to be downstream of the SREBP pathway in mammals. We identified 28 NRs by microarray whose expression changes during refeeding after being starved. When individually knocked down by RNAi, 11 NRs among 28 affect both fat storage and satiety behavior. Our results show that the major fat metabolism pathway regulates feeding behavior and NRs could be the mediators to link the feeding behavior to the metabolic changes. PMID:27097601

  9. High Throughput Interrogation of Behavioral Transitions in C. elegans

    NASA Astrophysics Data System (ADS)

    Liu, Mochi; Shaevitz, Joshua; Leifer, Andrew

    We present a high-throughput method to probe transformations from neural activity to behavior in Caenorhabditis elegans to better understand how organisms change behavioral states. We optogenetically deliver white-noise stimuli to target sensory or inter neurons while simultaneously recording the movement of a population of worms. Using all the postural movement data collected, we computationally classify stereotyped behaviors in C. elegans by clustering based on the spectral properties of the instantaneous posture. (Berman et al., 2014) Transitions between these behavioral clusters indicate discrete behavioral changes. To study the neural correlates dictating these transitions, we perform model-driven experiments and employ Linear-Nonlinear-Poisson cascades that take the white-noise stimulus as the input. The parameters of these models are fitted by reverse-correlation from our measurements. The parameterized models of behavioral transitions predict the worm's response to novel stimuli and reveal the internal computations the animal makes before carrying out behavioral decisions. Preliminary results are shown that describe the neural-behavioral transformation between neural activity in mechanosensory neurons and reversal behavior.

  10. Comparative Developmental Expression Profiling of Two C. elegans Isolates

    PubMed Central

    Capra, Emily J.; Skrovanek, Sonja M.; Kruglyak, Leonid

    2008-01-01

    Gene expression is known to change during development and to vary among genetically diverse strains. Previous studies of temporal patterns of gene expression during C. elegans development were incomplete, and little is known about how these patterns change as a function of genetic background. We used microarrays that comprehensively cover known and predicted worm genes to compare the landscape of genetic variation over developmental time between two isolates of C. elegans. We show that most genes vary in expression during development from egg to young adult, many genes vary in expression between the two isolates, and a subset of these genes exhibit isolate-specific changes during some developmental stages. This subset is strongly enriched for genes with roles in innate immunity. We identify several novel motifs that appear to play a role in regulating gene expression during development, and we propose functional annotations for many previously unannotated genes. These results improve our understanding of gene expression and function during worm development and lay the foundation for linkage studies of the genetic basis of developmental variation in gene expression in this important model organism. PMID:19116648

  11. A Distributed Chemosensory Circuit for Oxygen Preference in C. elegans

    PubMed Central

    Chang, Andy J; Chronis, Nikolas; Karow, David S; Marletta, Michael A; Bargmann, Cornelia I

    2006-01-01

    The nematode Caenorhabditis elegans has complex, naturally variable behavioral responses to environmental oxygen, food, and other animals. C. elegans detects oxygen through soluble guanylate cyclase homologs (sGCs) and responds to it differently depending on the activity of the neuropeptide receptor NPR-1: npr-1(lf) and naturally isolated npr-1(215F) animals avoid high oxygen and aggregate in the presence of food; npr-1(215V) animals do not. We show here that hyperoxia avoidance integrates food with npr-1 activity through neuromodulation of a distributed oxygen-sensing network. Hyperoxia avoidance is stimulated by sGC-expressing oxygen-sensing neurons, nociceptive neurons, and ADF sensory neurons. In npr-1(215V) animals, the switch from weak aerotaxis on food to strong aerotaxis in its absence requires close regulation of the neurotransmitter serotonin in the ADF neurons; high levels of ADF serotonin promote hyperoxia avoidance. In npr-1(lf) animals, food regulation is masked by increased activity of the oxygen-sensing neurons. Hyperoxia avoidance is also regulated by the neuronal TGF-β homolog DAF-7, a secreted mediator of crowding and stress responses. DAF-7 inhibits serotonin synthesis in ADF, suggesting that ADF serotonin is a convergence point for regulation of hyperoxia avoidance. Coalitions of neurons that promote and repress hyperoxia avoidance generate a subtle and flexible response to environmental oxygen. PMID:16903785

  12. Autophagy protects C. elegans against necrosis during Pseudomonas aeruginosa infection

    PubMed Central

    Zou, Cheng-Gang; Ma, Yi-Cheng; Dai, Li-Li; Zhang, Ke-Qin

    2014-01-01

    Autophagy, a conserved pathway that delivers intracellular materials into lysosomes for degradation, is involved in development, aging, and a variety of diseases. Accumulating evidence demonstrates that autophagy plays a protective role against infectious diseases by diminishing intracellular pathogens, including bacteria, viruses, and parasites. However, the mechanism by which autophagy regulates innate immunity remains largely unknown. Here, we show that autophagy is involved in host defense against a pathogenic bacterium Pseudomonas aeruginosa in the metazoan Caenorhabditis elegans. P. aeruginosa infection induces autophagy via a conserved extracellular signal-regulated kinase (ERK). Intriguingly, impairment of autophagy does not influence the intestinal accumulation of P. aeruginosa, but instead induces intestinal necrosis. Inhibition of necrosis results in the survival of autophagy-deficient worms after P. aeruginosa infection. These findings reveal a previously unidentified role for autophagy in protection against necrosis triggered by pathogenic bacteria in C. elegans and implicate that such a function of autophagy may be conserved through the inflammatory response in diverse organisms. PMID:25114220

  13. Differential Toxicities of Nickel Salts to the Nematode Caenorhabditis elegans.

    PubMed

    Meyer, Dean; Birdsey, Jennifer M; Wendolowski, Mark A; Dobbin, Kevin K; Williams, Phillip L

    2016-08-01

    This study focused on assessing whether nickel (Ni) toxicity to the nematode Caenorhabditis elegans was affected by the molecular structure of the Ni salt used. Nematodes were exposed to seven Ni salts [Ni sulfate hexahydrate (NiSO4·6H2O), Ni chloride hexahydrate (NiCl2·6H2O), Ni acetate tetrahydrate (Ni(OCOCH3)2·4H2O), Ni nitrate hexahydrate (N2NiO6·6H2O), anhydrous Ni iodide (NiI2), Ni sulfamate hydrate (Ni(SO3NH2)2·H2O), and Ni fluoride tetrahydrate (NiF2·4H2O)] in an aquatic medium for 24 h, and lethality curves were generated and analyzed. Ni fluoride, Ni iodide, and Ni chloride were most toxic to C. elegans, followed by Ni nitrate, Ni sulfamate, Ni acetate, and Ni sulfate. The LC50 values of the halogen-containing salts were statistically different from the corresponding value of the least toxic salt, Ni sulfate. This finding is consistent with the expected high bioavailability of free Ni ions in halide solutions. We recommend that the halide salts be used in future Ni testing involving aquatic invertebrates. PMID:27278637

  14. Multiple sites of action of volatile anesthetics in Caenorhabditis elegans.

    PubMed Central

    Morgan, P G; Sedensky, M; Meneely, P M

    1990-01-01

    The mechanism and site(s) of action of volatile anesthetics are unknown. In all organisms studied, volatile anesthetics adhere to the Meyer-Overton relationship--that is, a ln-ln plot of the oil-gas partition coefficients versus the potencies yields a straight line with a slope of -1. This relationship has led to two conclusions about the site of action of volatile anesthetics. (i) It has properties similar to the lipid used to determine the oil-gas partition coefficients. (ii) All volatile anesthetics cause anesthesia by affecting a single site. In Caenorhabditis elegans, we have identified two mutants with altered sensitivities to only some volatile anesthetics. These two mutants, unc-79 and unc-80, confer large increases in sensitivity to very lipid soluble agents but have little or no increases to other agents. In addition, a class of extragenic suppressor mutations exists that suppresses some altered sensitivities but specifically does not suppress the altered sensitivity to diethyl ether. There is much debate concerning the molecular nature of the site(s) of anesthetic action. One point of discussion is whether the site(s) consists of a purely lipid binding site or if protein is involved. The simplest explanation of our observations is that volatile anesthetics cause immobility in C. elegans by specifically interacting with multiple sites. This model is in turn more consistent with involvement of protein at the site(s) of action. PMID:2326259

  15. Proteomic identification of germline proteins in Caenorhabditis elegans

    PubMed Central

    Turner, B Elizabeth; Basecke, Sophia M; Bazan, Grace C; Dodge, Eric S; Haire, Cassy M; Heussman, Dylan J; Johnson, Chelsey L; Mukai, Chelsea K; Naccarati, Adrianna M; Norton, Sunny-June; Sato, Jennifer R; Talavera, Chihara O; Wade, Michael V; Hillers, Kenneth J

    2015-01-01

    Sexual reproduction involves fusion of 2 haploid gametes to form diploid offspring with genetic contributions from both parents. Gamete formation represents a unique developmental program involving the action of numerous germline-specific proteins. In an attempt to identify novel proteins involved in reproduction and embryonic development, we have carried out a proteomic characterization of the process in Caenorhabditis elegans. To identify candidate proteins, we used 2D gel electrophoresis (2DGE) to compare protein abundance in nucleus-enriched extracts from wild-type C. elegans, and in extracts from mutant worms with greatly reduced gonads (glp-4(bn2) worms reared at 25°C); 84 proteins whose abundance correlated with germline presence were identified. To validate candidates, we used feeding RNAi to deplete candidate proteins, and looked for reduction in fertility and/or germline cytological defects. Of 20 candidates so screened for involvement in fertility, depletion of 13 (65%) caused a significant reduction in fertility, and 6 (30%) resulted in sterility (<5 % of wild-type fertility). Five of the 13 proteins with demonstrated roles in fertility have not previously been implicated in germline function. The high frequency of defects observed after RNAi depletion of candidate proteins suggests that this approach is effective at identifying germline proteins, thus contributing to our understanding of this complex organ. PMID:26435885

  16. Bacopa monnieri promotes longevity in Caenorhabditis elegans under stress conditions

    PubMed Central

    Phulara, Suresh C.; Shukla, Virendra; Tiwari, Sudeep; Pandey, Rakesh

    2015-01-01

    Background: Bacopa monnieri (L.) Pennell, commonly known as Brahmi is an important medicinal plant traditionally used as memory enhancer and antiepileptic agent. Objective: The present study investigated antioxidant and stress resistance potentials of B. monnieri aqueous extract (BMW) using Caenorhabditis elegans animal model system. Materials and Methods: The antioxidant activity of the BMW was measured using in vitro (DPPH, reducing power and total polyphenol content) and in vivo (DCF-DA assay) assays. The antistress potential of BMW (0.1, 0.01, and 0.001 mg/ml) was evaluated through thermal stress (37°C) and oxidative stress (10 mM paraquat) using C. elegans. Quantification of the HSP-16.2 level was done using CL2070 transgenic worms. Results: Present study reveals that BMW possess in vitro and in vivo antioxidant activities. BMW significantly enhanced stress tolerance and increased the mean lifespan of worms during thermal and oxidative stress, although it did not extend lifespan at 20°C and attenuated age dependent decline in physiological behaviors. Moreover, it was shown that BMW was able to up-regulate expression of stress associated gene hsp-16.2, which significantly (P < 0.001) extends the mean lifespan of worms under stress conditions. Conclusion: The study strongly suggests that BMW acts as an antistressor and potent reactive oxygen species scavenger which enhances the survival of the worms in different stress conditions. PMID:25829783

  17. Controlling interneuron activity in Caenorhabditis elegans to evoke chemotactic behaviour.

    PubMed

    Kocabas, Askin; Shen, Ching-Han; Guo, Zengcai V; Ramanathan, Sharad

    2012-10-11

    Animals locate and track chemoattractive gradients in the environment to find food. With its small nervous system, Caenorhabditis elegans is a good model system in which to understand how the dynamics of neural activity control this search behaviour. Extensive work on the nematode has identified the neurons that are necessary for the different locomotory behaviours underlying chemotaxis through the use of laser ablation, activity recording in immobilized animals and the study of mutants. However, we do not know the neural activity patterns in C. elegans that are sufficient to control its complex chemotactic behaviour. To understand how the activity in its interneurons coordinate different motor programs to lead the animal to food, here we used optogenetics and new optical tools to manipulate neural activity directly in freely moving animals to evoke chemotactic behaviour. By deducing the classes of activity patterns triggered during chemotaxis and exciting individual neurons with these patterns, we identified interneurons that control the essential locomotory programs for this behaviour. Notably, we discovered that controlling the dynamics of activity in just one interneuron pair (AIY) was sufficient to force the animal to locate, turn towards and track virtual light gradients. Two distinct activity patterns triggered in AIY as the animal moved through the gradient controlled reversals and gradual turns to drive chemotactic behaviour. Because AIY neurons are post-synaptic to most chemosensory and thermosensory neurons, it is probable that these activity patterns in AIY have an important role in controlling and coordinating different taxis behaviours of the animal. PMID:23000898

  18. Genistein from Vigna angularis Extends Lifespan in Caenorhabditis elegans

    PubMed Central

    Lee, Eun Byeol; Ahn, Dalrae; Kim, Ban Ji; Lee, So Yeon; Seo, Hyun Won; Cha, Youn-Soo; Jeon, Hoon; Eun, Jae Soon; Cha, Dong Seok; Kim, Dae Keun

    2015-01-01

    The seed of Vigna angularis has long been cultivated as a food or a folk medicine in East Asia. Genistein (4′,5,7-trihydroxyisoflavone), a dietary phytoestrogen present in this plant, has been known to possess various biological properties. In this study, we investigated the possible lifespan-extending effects of genistein using Caenorhabditis elegans model system. We found that the lifespan of nematode was significantly prolonged in the presence of genistein under normal culture condition. In addition, genistein elevated the survival rate of nematode against stressful environment including heat and oxidative conditions. Further studies demonstrated that genistein-mediated increased stress tolerance of nematode could be attributed to enhanced expressions of stress resistance proteins such as superoxide dismutase (SOD-3) and heat shock protein (HSP-16.2). Moreover, we failed to find genistein-induced significant change in aging-related factors including reproduction, food intake, and growth, indicating genistein exerts longevity activity independent of affecting these factors. Genistein treatment also led to an up-regulation of locomotory ability of aged nematode, suggesting genistein affects healthspan as well as lifespan of nematode. Our results represent that genistein has beneficial effects on the lifespan of C. elegans under both of normal and stress condition via elevating expressions of stress resistance proteins. PMID:25593647

  19. Propulsion of C. elegans crawling on a wet surface

    NASA Astrophysics Data System (ADS)

    Bilbao, A.; Alavalapadu, A.; Khan, Z. S.; Salomon, D. E.; Vanapalli, S. A.; Rumbaugh, K.; Blawzdziewicz, J.

    2011-11-01

    Nematodes, such as soil-dwelling worms C. elegans, propel themselves by producing undulatory body motion. An important requirement for effective propulsion is to have large transverse and small longitudinal friction forces acting on a crawling worm. Recently, Sauvage et al. have shown that soft-lubrication forces between the worm body and a moist supporting substrate can produce, at most, the transverse friction coefficient twice as large as the longitudinal friction coefficient (and this ratio is too small for efficient propulsion). Here we show that hydrodynamic resistance of the fluid in liquid film adjacent to the worm body can generate significantly larger transverse friction, which moreover, is wavelength dependent. By modeling the worm as a long chain of spheres in Hele--Shaw flow, we have determined the optimal wavelength and amplitude of the undulatory motion that optimizes propulsion efficiency for a given rate of energy dissipation. The optimal worm shape qualitatively agrees with our experimental observations of C. elegans crawling in moist environments. This work was supported by NSF Grant No. CBET-1059745.

  20. Magnetosensitive neurons mediate geomagnetic orientation in Caenorhabditis elegans

    PubMed Central

    Vidal-Gadea, Andrés; Ward, Kristi; Beron, Celia; Ghorashian, Navid; Gokce, Sertan; Russell, Joshua; Truong, Nicholas; Parikh, Adhishri; Gadea, Otilia; Ben-Yakar, Adela; Pierce-Shimomura, Jonathan

    2015-01-01

    Many organisms spanning from bacteria to mammals orient to the earth's magnetic field. For a few animals, central neurons responsive to earth-strength magnetic fields have been identified; however, magnetosensory neurons have yet to be identified in any animal. We show that the nematode Caenorhabditis elegans orients to the earth's magnetic field during vertical burrowing migrations. Well-fed worms migrated up, while starved worms migrated down. Populations isolated from around the world, migrated at angles to the magnetic vector that would optimize vertical translation in their native soil, with northern- and southern-hemisphere worms displaying opposite migratory preferences. Magnetic orientation and vertical migrations required the TAX-4 cyclic nucleotide-gated ion channel in the AFD sensory neuron pair. Calcium imaging showed that these neurons respond to magnetic fields even without synaptic input. C. elegans may have adapted magnetic orientation to simplify their vertical burrowing migration by reducing the orientation task from three dimensions to one. DOI: http://dx.doi.org/10.7554/eLife.07493.001 PMID:26083711

  1. Starvation-induced collective behavior in C. elegans

    PubMed Central

    Artyukhin, Alexander B.; Yim, Joshua J.; Cheong Cheong, Mi; Avery, Leon

    2015-01-01

    We describe a new type of collective behavior in C. elegans nematodes, aggregation of starved L1 larvae. Shortly after hatching in the absence of food, L1 larvae arrest their development and disperse in search for food. In contrast, after two or more days without food, the worms change their behavior—they start to aggregate. The aggregation requires a small amount of ethanol or acetate in the environment. In the case of ethanol, it has to be metabolized, which requires functional alcohol dehydrogenase sodh-1. The resulting acetate is used in de novo fatty acid synthesis, and some of the newly made fatty acids are then derivatized to glycerophosphoethanolamides and released into the surrounding medium. We examined several other Caenorhabditis species and found an apparent correlation between propensity of starved L1s to aggregate and density dependence of their survival in starvation. Aggregation locally concentrates worms and may help the larvae to survive long starvation. This work demonstrates how presence of ethanol or acetate, relatively abundant small molecules in the environment, induces collective behavior in C. elegans associated with different survival strategies. PMID:26013573

  2. Emergence of long timescales and stereotyped behaviors in Caenorhabditis elegans.

    PubMed

    Stephens, Greg J; Bueno de Mesquita, Matthew; Ryu, William S; Bialek, William

    2011-05-01

    Animal behaviors often are decomposable into discrete, stereotyped elements, well separated in time. In one model, such behaviors are triggered by specific commands; in the extreme case, the discreteness of behavior is traced to the discreteness of action potentials in the individual command neurons. Here, we use the crawling behavior of the nematode Caenorhabditis elegans to demonstrate the opposite view, in which discreteness, stereotypy, and long timescales emerge from the collective dynamics of the behavior itself. In previous work, we found that as C. elegans crawls, its body moves through a "shape space" in which four dimensions capture approximately 95% of the variance in body shape. Here we show that stochastic dynamics within this shape space predicts transitions between attractors corresponding to abrupt reversals in crawling direction. With no free parameters, our inferred stochastic dynamical system generates reversal timescales and stereotyped trajectories in close agreement with experimental observations. We use the stochastic dynamics to show that the noise amplitude decreases systematically with increasing time away from food, resulting in longer bouts of forward crawling and suggesting that worms can use noise to modify their locomotory behavior. PMID:21502536

  3. The ubiquitin proteasome system in Caenorhabditis elegans and its regulation☆

    PubMed Central

    Papaevgeniou, Nikoletta; Chondrogianni, Niki

    2014-01-01

    Protein degradation constitutes a major cellular function that is responsible for maintenance of the normal cellular physiology either through the degradation of normal proteins or through the elimination of damaged proteins. The Ubiquitin–Proteasome System (UPS)1 is one of the main proteolytic systems that orchestrate protein degradation. Given that up- and down- regulation of the UPS system has been shown to occur in various normal (such as ageing) and pathological (such as neurodegenerative diseases) processes, the exogenous modulation of the UPS function and activity holds promise of (a) developing new therapeutic interventions against various diseases and (b) establishing strategies to maintain cellular homeostasis. Since the proteasome genes are evolutionarily conserved, their role can be dissected in simple model organisms, such as the nematode, Caenorhabditis elegans. In this review, we survey findings on the redox regulation of the UPS in C. elegans showing that the nematode is an instrumental tool in the identification of major players in the UPS pathway. Moreover, we specifically discuss UPS-related genes that have been modulated in the nematode and in human cells and have resulted in similar effects thus further exhibiting the value of this model in the study of the UPS. PMID:24563851

  4. Neural integrity is maintained by dystrophin in C. elegans

    PubMed Central

    Zhou, Shan

    2011-01-01

    The dystrophin protein complex (DPC), composed of dystrophin and associated proteins, is essential for maintaining muscle membrane integrity. The link between mutations in dystrophin and the devastating muscle failure of Duchenne’s muscular dystrophy (DMD) has been well established. Less well appreciated are the accompanying cognitive impairment and neuropsychiatric disorders also presented in many DMD patients, which suggest a wider role for dystrophin in membrane–cytoskeleton function. This study provides genetic evidence of a novel role for DYS-1/dystrophin in maintaining neural organization in Caenorhabditis elegans. This neuronal function is distinct from the established role of DYS-1/dystrophin in maintaining muscle integrity and regulating locomotion. SAX-7, an L1 cell adhesion molecule (CAM) homologue, and STN-2/γ-syntrophin also function to maintain neural integrity in C. elegans. This study provides biochemical data that show that SAX-7 associates with DYS-1 in an STN-2/γ-syntrophin–dependent manner. These results reveal a recruitment of L1CAMs to the DPC to ensure neural integrity is maintained. PMID:21242290

  5. Characterization of mitochondrial thioredoxin reductase from C. elegans

    SciTech Connect

    Lacey, Brian M.; Hondal, Robert J. . E-mail: Robert.Hondal@uvm.edu

    2006-08-04

    Thioredoxin reductase catalyzes the NADPH-dependent reduction of the catalytic disulfide bond of thioredoxin. In mammals and other higher eukaryotes, thioredoxin reductases contain the rare amino acid selenocysteine at the active site. The mitochondrial enzyme from Caenorhabditis elegans, however, contains a cysteine residue in place of selenocysteine. The mitochondrial C. elegans thioredoxin reductase was cloned from an expressed sequence tag and then produced in Escherichia coli as an intein-fusion protein. The purified recombinant enzyme has a k {sub cat} of 610 min{sup -1} and a K {sub m} of 610 {mu}M using E. coli thioredoxin as substrate. The reported k {sub cat} is 25% of the k {sub cat} of the mammalian enzyme and is 43-fold higher than a cysteine mutant of mammalian thioredoxin reductase. The enzyme would reduce selenocysteine, but not hydrogen peroxide or insulin. The flanking glycine residues of the GCCG motif were mutated to serine. The mutants improved substrate binding, but decreased the catalytic rate.

  6. Ethylene stimulates tracheary element differentiation in Zinnia elegans cell cultures.

    PubMed

    Pesquet, Edouard; Tuominen, Hannele

    2011-04-01

    The exact role of ethylene in xylogenesis remains unclear, but the Zinnia elegans cell culture system provides an excellent model with which to study its role during the differentiation of tracheary elements (TEs) in vitro. Here, we analysed ethylene homeostasis and function during Z. elegans TE differentiation using biochemical, molecular and pharmacological methods. Ethylene evolution was confined to specific stages of TE differentiation. It was found to peak at the time of TE maturation and to correlate with the activity of the ethylene biosynthetic 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase. The ethylene precursor ACC was exported and accumulated to high concentrations in the extracellular medium, which also displayed a high capacity to convert ACC into ethylene. The effects of adding inhibitors of the ethylene biosynthetic ACC synthase and ACC oxidase enzymes to the TE cultures demonstrated for the first time strict dependence of TE differentiation on ethylene biosynthesis and a stimulatory effect of ethylene on the rate of TE differentiation. In a whole-plant context, our results suggest that ethylene synthesis occurs in the apoplast of the xylem elements and that ethylene participates, in a paracrine manner, in the control of the cambial stem cell pool size during secondary xylem formation. PMID:21219334

  7. Ecotoxicological assessment of lanthanum with Caenorhabditis elegans in liquid medium.

    PubMed

    Zhang, Haifeng; He, Xiao; Bai, Wei; Guo, Xiaomei; Zhang, Zhiyong; Chai, Zhifang; Zhao, Yuliang

    2010-12-01

    With their widespread applications in industry, agriculture and many other fields, more and more rare earth elements (REEs) are getting into the environment, especially the aquatic systems. Therefore, understanding the aquatic ecotoxicity of REEs has become more and more important. In the present work, Caenorhabditis elegans (C. elegans) was used as a test organism and life-cycle endpoints were chosen along with elemental assay to evaluate the aquatic toxicity of lanthanum (La), a representative of REEs. The results show La³+ had significant adverse effects on the growth and reproduction of worms above a concentration of 10 μmol L⁻¹. The elemental mapping by microbeam synchrotron radiation X-ray fluorescence (μ-SRXRF) illustrated how La treatment disturbed the metals distribution in the whole body of a single tiny nematode at lower levels. Our results suggested that the high-level REEs in some polluted water bodies would lead to an aquatic ecological crisis. The assessment we performed in the present work could be developed as a standardized test design for aquatic toxicological research. PMID:21510015

  8. Candicidin-producing Streptomyces support leaf-cutting ants to protect their fungus garden against the pathogenic fungus Escovopsis

    PubMed Central

    Haeder, Susanne; Wirth, Rainer; Herz, Hubert; Spiteller, Dieter

    2009-01-01

    Leaf-cutting ants such as Acromyrmex octospinosus live in obligate symbiosis with fungi of the genus Leucoagaricus, which they grow with harvested leaf material. The symbiotic fungi, in turn, serve as a major food source for the ants. This mutualistic relation is disturbed by the specialized pathogenic fungus Escovopsis sp., which can overcome Leucoagaricus sp. and thus destroy the ant colony. Microbial symbionts of leaf-cutting ants have been suggested to protect the fungus garden against Escovopsis by producing antifungal compounds [Currie CR, Scott JA, Summerbell RC, Malloch D (1999) Fungus-growing ants use antibiotic-producing bacteria to control garden parasites. Nature 398:701–704.]. To date, however, the chemical nature of these compounds has remained elusive. We characterized 19 leaf-cutting ant–associated microorganisms (5 Pseudonocardia, 1 Dermacoccus, and 13 Streptomyces) from 3 Acromyrmex species, A. octospinosus, A. echinatior, and A. volcanus, using 16S-rDNA analysis. Because the strain Streptomyces sp. Ao10 proved highly active against the pathogen Escovopsis, we identified the molecular basis of its antifungal activity. Using bioassay-guided fractionation, high-resolution electrospray mass spectrometry (HR-ESI-MS), and UV spectroscopy, and comparing the results with an authentic standard, we were able identify candicidin macrolides. Candicidin macrolides are highly active against Escovopsis but do not significantly affect the growth of the symbiotic fungus. At least one of the microbial isolates from each of the 3 leaf-cutting ant species analyzed produced candicidin macrolides. This suggests that candicidins play an important role in protecting the fungus gardens of leaf-cutting ants against pathogenic fungi. PMID:19270078

  9. Sensory roles of neuronal cilia: cilia development, morphogenesis, and function in C. elegans.

    PubMed

    Bae, Young-Kyung; Barr, Maureen M

    2008-01-01

    In the free-living nematode Caenorhabditis elegans, cilia are found on the dendritic endings of sensory neurons. C. elegans cilia are classified as 'primary' or 'sensory' according to the '9+0' axonemal ultrastructure (nine doublet outer microtubules with no central microtubule pair) and lack of motility, characteristics of '9+2' cilia. The C. elegans ciliated nervous system allows the animal to perceive environmental stimuli and make appropriate developmental, physiological, and behavioral decisions. In vertebrates, the biological significance of primary cilia had been largely neglected. Recent findings have placed primary/sensory cilia in the center of cellular signaling and developmental processes. Studies using genetic model organisms such as C. elegans identified the link between ciliary dysfunction and human ciliopathies. Future studies in the worm will address important basic questions regarding ciliary development, morphogenesis, specialization, and signaling functions. PMID:18508635

  10. Communication between oocytes and somatic cells regulates volatile pheromone production in Caenorhabditis elegans.

    PubMed

    Leighton, Daniel H W; Choe, Andrea; Wu, Shannon Y; Sternberg, Paul W

    2014-12-16

    Males of the androdioecious species Caenorhabditis elegans are more likely to attempt to mate with and successfully inseminate C. elegans hermaphrodites that do not concurrently harbor sperm. Although a small number of genes have been implicated in this effect, the mechanism by which it arises remains unknown. In the context of the battle of the sexes, it is also unknown whether this effect is to the benefit of the male, the hermaphrodite, or both. We report that successful contact between mature sperm and oocyte in the C. elegans gonad at the start of fertilization causes the oocyte to release a signal that is transmitted to somatic cells in its mother, with the ultimate effect of reducing her attractiveness to males. Changes in hermaphrodite attractiveness are tied to the production of a volatile pheromone, the first such pheromone described in C. elegans. PMID:25453110

  11. The neural circuits and sensory channels mediating harsh touch sensation in C. elegans

    PubMed Central

    Li, Wei; Kang, Lijun; Piggott, Beverly J.; Feng, Zhaoyang; Shawn Xu, X. Z.

    2011-01-01

    Most animals can distinguish two distinct types of touch stimuli: gentle (innocuous) and harsh (noxious/painful) touch, but the underlying mechanisms are not well understood. C. elegans is a highly successful model for the study of gentle touch sensation. However, little is known about harsh touch sensation in this organism. Here we characterize harsh touch sensation in C. elegans. We show that C. elegans exhibits differential behavioral responses to harsh touch and gentle touch. Laser ablations identify distinct sets of sensory neurons and interneurons required for harsh touch sensation at different body segments. Optogenetic stimulation of the circuitry can drive behavior. Patch-clamp recordings reveal that TRP family and amiloride-sensitive Na+ channels mediate touch-evoked currents in different sensory neurons. Our work identifies the neural circuits and characterizes the sensory channels mediating harsh touch sensation in C. elegans, establishing it as a genetic model for studying this sensory modality. PMID:21587232

  12. Lipid signalling couples translational surveillance to systemic detoxification in Caenorhabditis elegans

    PubMed Central

    Govindan, J. Amaranath; Jayamani, Elamparithi; Zhang, Xinrui; Breen, Peter; Larkins-Ford, Jonah; Mylonakis, Eleftherios

    2015-01-01

    Translation in eukaryotes is surveilled to detect toxins and virulence factors and coupled to the induction of defense pathways. C. elegans germline-specific mutations in translation components are detected by this system to induce detoxification and immune responses in distinct somatic cells. An RNAi screen revealed gene inactivations that act at multiple steps in lipid biosynthetic and kinase pathways that act upstream of MAP kinase to mediate the systemic communication of translation-defects to induce detoxification genes. Mammalian bile acids can rescue the defect in detoxification gene induction caused by C. elegans lipid biosynthetic gene inactivations. Extracts prepared from C. elegans with translation deficits but not from wild type can also rescue detoxification gene induction in lipid biosynthetic defective strains. These eukaryotic antibacterial countermeasures are not ignored by bacteria: particular bacterial species suppress normal C. elegans detoxification responses to mutations in translation factors. PMID:26322678

  13. Efficient genome editing in Caenorhabditis elegans by CRISPR-targeted homologous recombination.

    PubMed

    Chen, Changchun; Fenk, Lorenz A; de Bono, Mario

    2013-11-01

    Cas9 is an RNA-guided double-stranded DNA nuclease that participates in clustered regularly interspaced short palindromic repeats (CRISPR)-mediated adaptive immunity in prokaryotes. CRISPR-Cas9 has recently been used to generate insertion and deletion mutations in Caenorhabditis elegans, but not to create tailored changes (knock-ins). We show that the CRISPR-CRISPR-associated (Cas) system can be adapted for efficient and precise editing of the C. elegans genome. The targeted double-strand breaks generated by CRISPR are substrates for transgene-instructed gene conversion. This allows customized changes in the C. elegans genome by homologous recombination: sequences contained in the repair template (the transgene) are copied by gene conversion into the genome. The possibility to edit the C. elegans genome at selected locations will facilitate the systematic study of gene function in this widely used model organism. PMID:24013562

  14. A co-CRISPR strategy for efficient genome editing in Caenorhabditis elegans.

    PubMed

    Kim, Heesun; Ishidate, Takao; Ghanta, Krishna S; Seth, Meetu; Conte, Darryl; Shirayama, Masaki; Mello, Craig C

    2014-08-01

    Genome editing based on CRISPR (clustered regularly interspaced short palindromic repeats)-associated nuclease (Cas9) has been successfully applied in dozens of diverse plant and animal species, including the nematode Caenorhabditis elegans. The rapid life cycle and easy access to the ovary by micro-injection make C. elegans an ideal organism both for applying CRISPR-Cas9 genome editing technology and for optimizing genome-editing protocols. Here we report efficient and straightforward CRISPR-Cas9 genome-editing methods for C. elegans, including a Co-CRISPR strategy that facilitates detection of genome-editing events. We describe methods for detecting homologous recombination (HR) events, including direct screening methods as well as new selection/counterselection strategies. Our findings reveal a surprisingly high frequency of HR-mediated gene conversion, making it possible to rapidly and precisely edit the C. elegans genome both with and without the use of co-inserted marker genes. PMID:24879462

  15. The C. elegans Crumbs family contains a CRB3 homolog and is not essential for viability.

    PubMed

    Waaijers, Selma; Ramalho, João Jacob; Koorman, Thijs; Kruse, Elisabeth; Boxem, Mike

    2015-01-01

    Crumbs proteins are important regulators of epithelial polarity. In C. elegans, no essential role for the two described Crumbs homologs has been uncovered. Here, we identify and characterize an additional Crumbs family member in C. elegans, which we termed CRB-3 based on its similarity in size and sequence to mammalian CRB3. We visualized CRB-3 subcellular localization by expressing a translational GFP fusion. CRB-3::GFP was expressed in several polarized tissues in the embryo and larval stages, and showed apical localization in the intestine and pharynx. To identify the function of the Crumbs family in C. elegans development, we generated a triple Crumbs deletion mutant by sequentially removing the entire coding sequence for each crumbs homolog using a CRISPR/Cas9-based approach. Remarkably, animals lacking all three Crumbs homologs are viable and show normal epithelial polarity. Thus, the three C. elegans Crumbs family members do not appear to play an essential role in epithelial polarity establishment. PMID:25661870

  16. A Co-CRISPR Strategy for Efficient Genome Editing in Caenorhabditis elegans

    PubMed Central

    Kim, Heesun; Ishidate, Takao; Ghanta, Krishna S.; Seth, Meetu; Conte, Darryl; Shirayama, Masaki; Mello, Craig C.

    2014-01-01

    Genome editing based on CRISPR (clustered regularly interspaced short palindromic repeats)-associated nuclease (Cas9) has been successfully applied in dozens of diverse plant and animal species, including the nematode Caenorhabditis elegans. The rapid life cycle and easy access to the ovary by micro-injection make C. elegans an ideal organism both for applying CRISPR-Cas9 genome editing technology and for optimizing genome-editing protocols. Here we report efficient and straightforward CRISPR-Cas9 genome-editing methods for C. elegans, including a Co-CRISPR strategy that facilitates detection of genome-editing events. We describe methods for detecting homologous recombination (HR) events, including direct screening methods as well as new selection/counterselection strategies. Our findings reveal a surprisingly high frequency of HR-mediated gene conversion, making it possible to rapidly and precisely edit the C. elegans genome both with and without the use of co-inserted marker genes. PMID:24879462

  17. Efficient genome editing in Caenorhabditis elegans by CRISPR-targeted homologous recombination

    PubMed Central

    Chen, Changchun; Fenk, Lorenz A.; de Bono, Mario

    2013-01-01

    Cas9 is an RNA-guided double-stranded DNA nuclease that participates in clustered regularly interspaced short palindromic repeats (CRISPR)-mediated adaptive immunity in prokaryotes. CRISPR–Cas9 has recently been used to generate insertion and deletion mutations in Caenorhabditis elegans, but not to create tailored changes (knock-ins). We show that the CRISPR–CRISPR-associated (Cas) system can be adapted for efficient and precise editing of the C. elegans genome. The targeted double-strand breaks generated by CRISPR are substrates for transgene-instructed gene conversion. This allows customized changes in the C. elegans genome by homologous recombination: sequences contained in the repair template (the transgene) are copied by gene conversion into the genome. The possibility to edit the C. elegans genome at selected locations will facilitate the systematic study of gene function in this widely used model organism. PMID:24013562

  18. Insulin signaling genes modulate nicotine-induced behavioral responses in Caenorhabditis elegans.

    PubMed

    Wescott, Seth A; Ronan, Elizabeth A; Xu, X Z Shawn

    2016-02-01

    Insulin signaling has been suggested to modulate nicotine dependence, but the underlying genetic evidence has been lacking. Here, we used the nematode, Caenorhabditis elegans, to investigate whether genetic alterations in the insulin signaling pathway affect behavioral responses to nicotine. For this, we challenged drug-naive C. elegans with an acute dose of nicotine (100 μmol/l) while recording changes in their locomotion speed. Although nicotine treatment stimulated locomotion speed in wild-type C. elegans, the same treatment reduced locomotion speed in mutants defective in insulin signaling. This phenotype could be suppressed by mutations in daf-16, a gene encoding a FOXO transcription factor that acts downstream of insulin signaling. Our data suggest that insulin signaling genes, daf-2, age-1, pdk-1, akt-1, and akt-2, modulate behavioral responses to nicotine in C. elegans, indicating a genetic link between nicotine behavior and insulin signaling. PMID:26317299

  19. Communication between oocytes and somatic cells regulates volatile pheromone production in Caenorhabditis elegans

    PubMed Central

    Leighton, Daniel H. W.; Choe, Andrea; Wu, Shannon Y; Sternberg, Paul W.

    2014-01-01

    Males of the androdioecious species Caenorhabditis elegans are more likely to attempt to mate with and successfully inseminate C. elegans hermaphrodites that do not concurrently harbor sperm. Although a small number of genes have been implicated in this effect, the mechanism by which it arises remains unknown. In the context of the battle of the sexes, it is also unknown whether this effect is to the benefit of the male, the hermaphrodite, or both. We report that successful contact between mature sperm and oocyte in the C. elegans gonad at the start of fertilization causes the oocyte to release a signal that is transmitted to somatic cells in its mother, with the ultimate effect of reducing her attractiveness to males. Changes in hermaphrodite attractiveness are tied to the production of a volatile pheromone, the first such pheromone described in C. elegans. PMID:25453110

  20. RNA editing by ADARs is important for normal behavior in Caenorhabditis elegans.

    PubMed

    Tonkin, Leath A; Saccomanno, Lisa; Morse, Daniel P; Brodigan, Thomas; Krause, Michael; Bass, Brenda L

    2002-11-15

    Here we take advantage of the well-characterized and simple nervous system of Caenorhabditis elegans to further our understanding of the functions of RNA editing. We describe the two C.elegans ADAR genes, adr-1 and adr-2, and characterize strains containing homozygous deletions in each, or both, of these genes. We find that adr-1 is expressed in most, if not all, cells of the C.elegans nervous system and also in the developing vulva. Using chemotaxis assays, we show that both ADARs are important for normal behavior. Biochemical, molecular and phenotypic analyses indicate that ADR-1 and ADR-2 have distinct roles in C.elegans, but sometimes act together. PMID:12426375

  1. Thermal stress resistance and aging effects of Panax notoginseng polysaccharides on Caenorhabditis elegans.

    PubMed

    Feng, Shiling; Cheng, Haoran; Xu, Zhou; Shen, Shian; Yuan, Ming; Liu, Jing; Ding, Chunbang

    2015-11-01

    Panax notoginseng attract public attention due to their potential biomedical properties and corresponding health benefits. The present study investigated the anti-aging and thermal stress resistance effects of polysaccharides from P. notoginseng on Caenorhabditis elegans. Results showed polysaccharides had little scavenging ability of reactive oxygen species (ROS) in vitro, but significantly extended lifespan of C. elegans, especially the main root polysaccharide (MRP) which prolongs the mean lifespan of wild type worms by 21%. Further study demonstrated that the heat stress resistance effect of polysaccharides on C. elegans might be attributed to the elevation of antioxidant enzyme activities (both superoxide dismutase (SOD) and catalase (CAT)) and the reduction lipid peroxidation of malondialdehyde (MDA) level. Taken together, the results provided a scientific basis for the further exploitation of the mechanism of longer lifespan controlled by P. notoginseng polysaccharides on C. elegans. The P. notoginseng polysaccharides might be considered as a potential source to delay aging. PMID:26234580

  2. Xyloketal-derived small molecules show protective effect by decreasing mutant Huntingtin protein aggregates in Caenorhabditis elegans model of Huntington's disease.

    PubMed

    Zeng, Yixuan; Guo, Wenyuan; Xu, Guangqing; Wang, Qinmei; Feng, Luyang; Long, Simei; Liang, Fengyin; Huang, Yi; Lu, Xilin; Li, Shichang; Zhou, Jiebin; Burgunder, Jean-Marc; Pang, Jiyan; Pei, Zhong

    2016-01-01

    Huntington's disease is an autosomal-dominant neurodegenerative disorder, with chorea as the most prominent manifestation. The disease is caused by abnormal expansion of CAG codon repeats in the IT15 gene, which leads to the expression of a glutamine-rich protein named mutant Huntingtin (Htt). Because of its devastating disease burden and lack of valid treatment, development of more effective therapeutics for Huntington's disease is urgently required. Xyloketal B, a natural product from mangrove fungus, has shown protective effects against toxicity in other neurodegenerative disease models such as Parkinson's and Alzheimer's diseases. To identify potential neuroprotective molecules for Huntington's disease, six derivatives of xyloketal B were screened in a Caenorhabditis elegans Huntington's disease model; all six compounds showed a protective effect. Molecular docking studies indicated that compound 1 could bind to residues GLN369 and GLN393 of the mutant Htt protein, forming a stable trimeric complex that can prevent the formation of mutant Htt aggregates. Taken together, we conclude that xyloketal derivatives could be novel drug candidates for treating Huntington's disease. Molecular target analysis is a good method to simulate the interaction between proteins and drug compounds. Further, protective candidate drugs could be designed in future using the guidance of molecular docking results. PMID:27110099

  3. Xyloketal-derived small molecules show protective effect by decreasing mutant Huntingtin protein aggregates in Caenorhabditis elegans model of Huntington’s disease

    PubMed Central

    Zeng, Yixuan; Guo, Wenyuan; Xu, Guangqing; Wang, Qinmei; Feng, Luyang; Long, Simei; Liang, Fengyin; Huang, Yi; Lu, Xilin; Li, Shichang; Zhou, Jiebin; Burgunder, Jean-Marc; Pang, Jiyan; Pei, Zhong

    2016-01-01

    Huntington’s disease is an autosomal-dominant neurodegenerative disorder, with chorea as the most prominent manifestation. The disease is caused by abnormal expansion of CAG codon repeats in the IT15 gene, which leads to the expression of a glutamine-rich protein named mutant Huntingtin (Htt). Because of its devastating disease burden and lack of valid treatment, development of more effective therapeutics for Huntington’s disease is urgently required. Xyloketal B, a natural product from mangrove fungus, has shown protective effects against toxicity in other neurodegenerative disease models such as Parkinson’s and Alzheimer’s diseases. To identify potential neuroprotective molecules for Huntington’s disease, six derivatives of xyloketal B were screened in a Caenorhabditis elegans Huntington’s disease model; all six compounds showed a protective effect. Molecular docking studies indicated that compound 1 could bind to residues GLN369 and GLN393 of the mutant Htt protein, forming a stable trimeric complex that can prevent the formation of mutant Htt aggregates. Taken together, we conclude that xyloketal derivatives could be novel drug candidates for treating Huntington’s disease. Molecular target analysis is a good method to simulate the interaction between proteins and drug compounds. Further, protective candidate drugs could be designed in future using the guidance of molecular docking results. PMID:27110099

  4. Distinct Pathogenesis and Host Responses during Infection of C. elegans by P. aeruginosa and S. aureus

    PubMed Central

    Irazoqui, Javier E.; Troemel, Emily R.; Feinbaum, Rhonda L.; Luhachack, Lyly G.; Cezairliyan, Brent O.; Ausubel, Frederick M.

    2010-01-01

    The genetically tractable model host Caenorhabditis elegans provides a valuable tool to dissect host-microbe interactions in vivo. Pseudomonas aeruginosa and Staphylococcus aureus utilize virulence factors involved in human disease to infect and kill C. elegans. Despite much progress, virtually nothing is known regarding the cytopathology of infection and the proximate causes of nematode death. Using light and electron microscopy, we found that P. aeruginosa infection entails intestinal distention, accumulation of an unidentified extracellular matrix and P. aeruginosa-synthesized outer membrane vesicles in the gut lumen and on the apical surface of intestinal cells, the appearance of abnormal autophagosomes inside intestinal cells, and P. aeruginosa intracellular invasion of C. elegans. Importantly, heat-killed P. aeruginosa fails to elicit a significant host response, suggesting that the C. elegans response to P. aeruginosa is activated either by heat-labile signals or pathogen-induced damage. In contrast, S. aureus infection causes enterocyte effacement, intestinal epithelium destruction, and complete degradation of internal organs. S. aureus activates a strong transcriptional response in C. elegans intestinal epithelial cells, which aids host survival during infection and shares elements with human innate responses. The C. elegans genes induced in response to S. aureus are mostly distinct from those induced by P. aeruginosa. In contrast to P. aeruginosa, heat-killed S. aureus activates a similar response as live S. aureus, which appears to be independent of the single C. elegans Toll-Like Receptor (TLR) protein. These data suggest that the host response to S. aureus is possibly mediated by pathogen-associated molecular patterns (PAMPs). Because our data suggest that neither the P. aeruginosa nor the S. aureus–triggered response requires canonical TLR signaling, they imply the existence of unidentified mechanisms for pathogen detection in C. elegans, with

  5. Hydrogen Sulfide Is an Endogenous Regulator of Aging in Caenorhabditis elegans

    PubMed Central

    Qabazard, Bedoor; Li, Ling; Gruber, Jan; Peh, Meng Teng; Ng, Li Fang; Kumar, Srinivasan Dinesh; Rose, Peter; Tan, Choon-Hong; Dymock, Brian W.; Wei, Feng; Swain, Suresh C.; Halliwell, Barry

    2014-01-01

    Abstract Aims: To investigate the role of endogenous hydrogen sulfide (H2S) in the control of aging and healthspan of Caenorhabditis elegans. Results: We show that the model organism, C. elegans, synthesizes H2S. Three H2S-synthesizing enzymes are present in C. elegans, namely cystathionine γ lyase (CSE), cystathionine β synthetase, and 3-mercaptopyruvate transferase (MPST or 3-MST). Genetic deficiency of mpst-1 (3-MST orthologue 1), but not cth-2 (CSE orthologue), reduced the lifespan of C. elegans. This effect was reversed by a pharmacological H2S donor (GYY4137). GYY4137 also reduced detrimental age-dependent changes in a range of physiological indices, including pharyngeal contraction and defecation. Treatment of C. elegans with GYY4137 increased the expression of several age-related, stress response, and antioxidant genes, whereas MitoSOX Red fluorescence, indicative of reactive oxygen species generation, was increased in mpst-1 knockouts and decreased by GYY4137 treatment. GYY4137 additionally increased the lifespan in short-lived mev-1 mutants with elevated oxidative stress and protected wild-type C. elegans against paraquat poisoning. The lifespan-prolonging and health-promoting effects of H2S in C. elegans are likely due to the antioxidant action of this highly cell-permeable gas. Innovation: The possibility that novel pharmacological agents based on the principle of H2S donation may be able to retard the onset of age-related disease by slowing the aging process warrants further study. Conclusion: Our results show that H2S is an endogenous regulator of oxidative damage, metabolism, and aging in C. elegans and provide new insight into the mechanisms, which control aging in this model organism. Antioxid. Redox Signal. 20, 2621–2630. PMID:24093496

  6. In vivo visualization and quantification of mitochondrial morphology in C. elegans.

    PubMed

    Smith, Reuben L; De Vos, Winnok H; de Boer, Richard; Manders, Erik M M; van der Spek, Hans

    2015-01-01

    Caenorhabditis elegans is a highly malleable model system, intensively used for functional, genetic, cytometric, and integrative studies. Due to its simplicity and large muscle cell number, C. elegans has frequently been used to study mitochondrial deficiencies caused by disease or drug toxicity. Here, we describe a robust and efficient method to visualize and quantify mitochondrial morphology in vivo. This method has many practical and technical advantages above traditional (manual) methods and provides a comprehensive analysis of mitochondrial morphology. PMID:25634288

  7. Homologous and unique G protein alpha subunits in the nematode Caenorhabditis elegans.

    PubMed Central

    Lochrie, M A; Mendel, J E; Sternberg, P W; Simon, M I

    1991-01-01

    A cDNA corresponding to a known G protein alpha subunit, the alpha subunit of Go (Go alpha), was isolated and sequenced. The predicted amino acid sequence of C. elegans Go alpha is 80-87% identical to other Go alpha sequences. An mRNA that hybridizes to the C. elegans Go alpha cDNA can be detected on Northern blots. A C. elegans protein that crossreacts with antibovine Go alpha antibody can be detected on immunoblots. A cosmid clone containing the C. elegans Go alpha gene (goa-1) was isolated and mapped to chromosome I. The genomic fragments of three other C. elegans G protein alpha subunit genes (gpa-1, gpa-2, and gpa-3) have been isolated using the polymerase chain reaction. The corresponding cosmid clones were isolated and mapped to disperse locations on chromosome V. The sequences of two of the genes, gpa-1 and gpa-3, were determined. The predicted amino acid sequences of gpa-1 and gpa-3 are only 48% identical to each other. Therefore, they are likely to have distinct functions. In addition they are not homologous enough to G protein alpha subunits in other organisms to be classified. Thus C. elegans has G proteins that are identifiable homologues of mammalian G proteins as well as G proteins that appear to be unique to C. elegans. Study of identifiable G proteins in C. elegans may result in a further understanding of their function in other organisms, whereas study of the novel G proteins may provide an understanding of unique aspects of nematode physiology. Images PMID:1907494

  8. Heritable genome editing in C. elegans via a CRISPR-Cas9 system.

    PubMed

    Friedland, Ari E; Tzur, Yonatan B; Esvelt, Kevin M; Colaiácovo, Monica P; Church, George M; Calarco, John A

    2013-08-01

    We report the use of clustered, regularly interspaced, short palindromic repeats (CRISPR)-associated endonuclease Cas9 to target genomic sequences in the Caenorhabditis elegans germ line using single-guide RNAs that are expressed from a U6 small nuclear RNA promoter. Our results demonstrate that targeted, heritable genetic alterations can be achieved in C. elegans, providing a convenient and effective approach for generating loss-of-function mutants. PMID:23817069

  9. Redescription of Pseudotropheus livingstonii and Pseudotropheus elegans from Lake Malaŵi, Africa.

    PubMed

    Stauffer, J R Jr; Konings, A F; Ryan, T M

    2016-01-01

    Pseudotropheus livingstonii and P. elegans are two sand-dwelling cichlid species that belong to the so-called mbuna, a group of predominantly rock-dwelling haplochromines of Lake Malaŵi. The identity of these two species has confused taxonomists for almost a century until a recent rediscovery of representatives of P. elegans close to its type locality. New diagnoses for both species are provided. PMID:27615832

  10. A conserved checkpoint monitors meiotic chromosome synapsis inCaenorhabditis elegans

    SciTech Connect

    Bhalla, Needhi; Dernburg, Abby F.

    2005-07-14

    We report the discovery of a checkpoint that monitorssynapsis between homologous chromosomes to ensure accurate meioticsegregation. Oocytes containing unsynapsed chromosomes selectivelyundergo apoptosis even if agermline DNA damage checkpoint is inactivated.This culling mechanism isspecifically activated by unsynapsed pairingcenters, cis-acting chromosomesites that are also required to promotesynapsis in Caenorhabditis elegans. Apoptosis due to synaptic failurealso requires the C. elegans homolog of PCH2,a budding yeast pachytenecheckpoint gene, which suggests that this surveillance mechanism iswidely conserved.

  11. White-nose syndrome fungus (Geomyces destructans) in bats, Europe

    USGS Publications Warehouse

    Wibbelt, G.; Kurth, A.; Hellmann, D.; Weishaar, M.; Barlow, A.; Veith, M.; Pruger, J.; Gorfol, T.; Grosche, T.; Bontadina, F.; Zophel, U.; Seidl, Hans-Peter; Cryan, P.M.; Blehert, D.S.

    2010-01-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

  12. White-Nose Syndrome Fungus (Geomyces destructans) in Bats, Europe

    PubMed Central

    Kurth, Andreas; Hellmann, David; Weishaar, Manfred; Barlow, Alex; Veith, Michael; Prüger, Julia; Görföl, Tamás; Grosche, Lena; Bontadina, Fabio; Zöphel, Ulrich; Seidl, Hans-Peter; Cryan, Paul M.; Blehert, David S.

    2010-01-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus. PMID:20678317

  13. Engineering a filamentous fungus for L-rhamnose extraction.

    PubMed

    Kuivanen, Joosu; Richard, Peter

    2016-03-01

    L-Rhamnose is a high value rare sugar that is used as such or after chemical conversions. It is enriched in several biomass fractions such as the pectic polysaccharides rhamnogalacturonan I and II and in naringin, hesperidin, rutin, quercitrin and ulvan. We engineered the filamentous fungus Aspergillus niger to not consume L-rhamnose, while it is still able to produce the enzymes for the hydrolysis of L-rhamnose rich biomass. As a result we present a strain that can be used for the extraction of L-rhamnose in a consolidated process. In the process the biomass is hydrolysed to the monomeric sugars which are consumed by the fungus leaving the L-rhamnose. PMID:27033543

  14. Mutualistic fungi control crop diversity in fungus-growing ants.

    PubMed

    Poulsen, Michael; Boomsma, Jacobus J

    2005-02-01

    Leaf-cutting ants rear clonal fungi for food and transmit the fungi from mother to daughter colonies so that symbiont mixing and conflict, which result from competition between genetically different clones, are avoided. Here we show that despite millions of years of predominantly vertical transmission, the domesticated fungi actively reject mycelial fragments from neighboring colonies, and that the strength of these reactions are in proportion to the overall genetic difference between these symbionts. Fungal incompatibility compounds remain intact during ant digestion, so that fecal droplets, which are used for manuring newly grown fungus, elicit similar hostile reactions when applied to symbionts from other colonies. Symbiont control over new mycelial growth by manurial imprinting prevents the rearing of multiple crops in fungus gardens belonging to the same colony. PMID:15692054

  15. Transformation of the mycorrhizal fungus Laccaria bicolor using Agrobacterium tumefaciens.

    PubMed

    Kemppainen, Minna J; Pardo, Alejandro G

    2011-01-01

    Most boreal and temperate forest trees form a mutualistic symbiosis with soil borne fungi called ectomycorrhiza (ECM). In this association both partners benefit due to nutrient exchange at the symbiotic interface. Laccaria bicolor is the first mycorrhizal fungus with its genome sequenced thus making possible for the first time to analyze genome scale gene expression profiles of a mutualistic fungus. However, in order to be able to take full advantage of the genome sequence, reverse genetic tools are needed. Among them a high throughput transformation system is crucial. Herein we present a detailed protocol for genetic transformation of L. bicolor by means of Agrobacterium tumefaciens with emphasis on critical steps affecting the success and efficiency of the approach. PMID:21636986

  16. Lactose enhances cellulase production by the filamentous fungus Acremonium cellulolyticus.

    PubMed

    Fang, Xu; Yano, Shinichi; Inoue, Hiroyuki; Sawayama, Shigeki

    2008-08-01

    Acremonium cellulolyticus is a fungus that produces cellulase and has been exploited by enzyme industry. To promote cellulase production by A. cellulolyticus strain C-1, we evaluated the effects of the saccharides: Solka Floc (cellulose), soluble soybean polysaccharide (SSPS), pullulan, lactose, trehalose, sophorose, cellobiose, galactose, sorbose, lactobionic acid, and mixtures as carbon sources for cellulase production. Solka Floc with SSPS enhanced cellulase production. Lactose as the sole carbon source induced cellulase synthesis in this fungus, and the synergistic effects between lactose and Solka Floc was observed. Various enzyme activities and the protein composition of crude enzyme produced by cultures with or without addition of lactose were analyzed. The results showed that lactose addition greatly improves the production of various proteins with cellulase activity by A. cellulolyticus. To our knowledge, this is the first report on production of cellulases by lactose in the A. cellulolyticus. PMID:18804052

  17. Extracellular biosynthesis of silver nanoparticles using the fungus Fusarium semitectum

    SciTech Connect

    Basavaraja, S.; Balaji, S.D.; Lagashetty, Arunkumar; Rajasab, A.H.; Venkataraman, A.

    2008-05-06

    Development of environmental friendly procedures for the synthesis of metal nanoparticles through biological processes is evolving into an important branch of nanobiotechnology. In this paper, we report on the use of fungus 'Fusarium semitectum' for the extracellular synthesis of silver nanoparticles from silver nitrate solution (i.e. through the reduction of Ag{sup +} to Ag{sup 0}). Highly stable and crystalline silver nanoparticles are produced in solution by treating the filtrate of the fungus F. semitectum with the aqueous silver nitrate solution. The formations of nanoparticles are understood from the UV-vis and X-ray diffraction studies. Transmission electron microscopy of the silver particles indicated that they ranged in size from 10 to 60 nm and are mostly spherical in shape. Interestingly the colloidal suspensions of silver nanoparticles are stable for many weeks. Possible medicinal applications of these silver nanoparticles are envisaged.

  18. Complete Genome Sequence of the Endophytic Fungus Diaporthe (Phomopsis) ampelina

    PubMed Central

    Bhargavi, S. D.; Praveen, V. K.

    2016-01-01

    Diaporthe ampelina was isolated as an endophytic fungus from the root of Commiphora wightii, a medicinal plant collected from Dhanvantri Vana, Bangalore University, Bangalore, India. The whole genome is 59 Mb, contains a total of 905 scaffolds, and has a G+C content of 51.74%. The genome sequence of D. ampelina shows a complete absence of lovastatin (an anticholesterol drug) gene cluster. PMID:27257198

  19. Metabolism of p-cresol by the fungus Aspergillus fumigatus

    SciTech Connect

    Jones, K.H.; Trudgill, P.W.; Hopper, D.J. )

    1993-04-01

    Cresols are phenolic compounds that are industrial pollutants. Degradation of p-cresol by several species of fungus has been reported. Aspergillus fumigatus ATCC 28282 metabolizes both phenylacetic and homogentisic acids. This study shows that A. fumigatus ATCC 28282 also is capable of growth on p-cresol as its sole carbon source. Two metabolic routes for p-cresol degradation are described in the paper, but the relative contributions of each pathway is not evaluated. 21 refs., 3 figs., 3 tabs.

  20. Complete Genome Sequence of the Endophytic Fungus Diaporthe (Phomopsis) ampelina.

    PubMed

    Savitha, J; Bhargavi, S D; Praveen, V K

    2016-01-01

    Diaporthe ampelina was isolated as an endophytic fungus from the root of Commiphora wightii, a medicinal plant collected from Dhanvantri Vana, Bangalore University, Bangalore, India. The whole genome is 59 Mb, contains a total of 905 scaffolds, and has a G+C content of 51.74%. The genome sequence of D. ampelina shows a complete absence of lovastatin (an anticholesterol drug) gene cluster. PMID:27257198

  1. Fungus mediated synthesis of biomedically important cerium oxide nanoparticles

    SciTech Connect

    Khan, Shadab Ali; Ahmad, Absar

    2013-10-15

    Graphical abstract: - Highlights: • First time biological synthesis of cerium oxide oxide nanoparticles using fungus Humicola sp. • Complete characterization of cerium oxide nanoparticles. • Biosynthesis of naturally protein capped, luminescent and water dispersible CeO{sub 2} nanoparticles. • Biosynthesized CeO{sub 2} nanoparticles can be used for many biomedical applications. - Abstract: Nanomaterials can be synthesized by chemical, physical and the more recently discovered biological routes. The biological routes are advantageous over the chemical and physical ones as unlike these, the biological synthesis protocols occur at ambient conditions, are cheap, non-toxic and eco-friendly. Although purely biological and bioinspired methods for the synthesis of nanomaterials are environmentally benign and energy conserving processes, their true potential has not been explored yet and attempts are being made to extend the formation of technologically important nanoparticles using microorganisms like fungi. Though there have been reports on the biosynthesis of oxide nanoparticles by our group in the past, no attempts have been made to employ fungi for the synthesis of nanoparticles of rare earth metals or lanthanides. Here we report for the first time, the bio-inspired synthesis of biomedically important cerium oxide (CeO{sub 2}) nanoparticles using the thermophilic fungus Humicola sp. The fungus Humicola sp. when exposed to aqueous solutions of oxide precursor cerium (III) nitrate hexahydrate (CeN{sub 3}O{sub 9}·6H{sub 2}O) results in the extracellular formation of CeO{sub 2} nanoparticles containing Ce (III) and Ce (IV) mixed oxidation states, confirmed by X-ray Photoemission Spectroscopy (XPS). The formed nanoparticles are naturally capped by proteins secreted by the fungus and thus do not agglomerate, are highly stable, water dispersible and are highly fluorescent as well. The biosynthesized nanoparticles were characterized by UV–vis spectroscopy

  2. Lasiodiplodins from mangrove endophytic fungus Lasiodiplodia sp. 318.

    PubMed

    Li, Jing; Xue, Yanyu; Yuan, Jie; Lu, Yongjun; Zhu, Xun; Lin, Yongcheng; Liu, Lan

    2016-04-01

    Four new lasiodiplodins (1-4), together with three known analogues, have been isolated from a mangrove endophytic fungus, Lasiodiplodia sp. 318#. Their structures were elucidated by spectroscopic techniques. Cytotoxic activities of compounds 1-7 were evaluated in vitro against human cancer lines THP1, MDA-MB-435, A549, HepG2 and HCT-116. Compound 4 exhibited moderate cytotoxic activities. PMID:26222141

  3. A C. elegans stretch receptor neuron revealed by a mechanosensitive TRP channel homologue.

    PubMed

    Li, Wei; Feng, Zhaoyang; Sternberg, Paul W; Xu, X Z Shawn

    2006-03-30

    The nematode Caenorhabditis elegans is commonly used as a genetic model organism for dissecting integration of the sensory and motor systems. Despite extensive genetic and behavioural analyses that have led to the identification of many genes and neural circuits involved in regulating C. elegans locomotion behaviour, it remains unclear whether and how somatosensory feedback modulates motor output during locomotion. In particular, no stretch receptors have been identified in C. elegans, raising the issue of whether stretch-receptor-mediated proprioception is used by C. elegans to regulate its locomotion behaviour. Here we have characterized TRP-4, the C. elegans homologue of the mechanosensitive TRPN channel. We show that trp-4 mutant worms bend their body abnormally, exhibiting a body posture distinct from that of wild-type worms during locomotion, suggesting that TRP-4 is involved in stretch-receptor-mediated proprioception. We show that TRP-4 acts in a single neuron, DVA, to mediate its function in proprioception, and that the activity of DVA can be stimulated by body stretch. DVA both positively and negatively modulates locomotion, providing a unique mechanism whereby a single neuron can fine-tune motor activity. Thus, DVA represents a stretch receptor neuron that regulates sensory-motor integration during C. elegans locomotion. PMID:16572173

  4. Solution structure of CEH-37 homeodomain of the nematode Caenorhabditis elegans

    SciTech Connect

    Moon, Sunjin; Lee, Yong Woo; Kim, Woo Taek; Lee, Weontae

    2014-01-10

    Highlights: •We have determined solution structures of CEH-37 homedomain. •CEH-37 HD has a compact α-helical structure with HTH DNA binding motif. •Solution structure of CEH-37 HD shares its molecular topology with that of the homeodomain proteins. •Residues in the N-terminal region and HTH motif are important in binding to Caenorhabditis elegans telomeric DNA. •CEH-37 could play an important role in telomere function via DNA binding. -- Abstract: The nematode Caenorhabditis elegans protein CEH-37 belongs to the paired OTD/OTX family of homeobox-containing homeodomain proteins. CEH-37 shares sequence similarity with homeodomain proteins, although it specifically binds to double-stranded C. elegans telomeric DNA, which is unusual to homeodomain proteins. Here, we report the solution structure of CEH-37 homeodomain and molecular interaction with double-stranded C. elegans telomeric DNA using nuclear magnetic resonance (NMR) spectroscopy. NMR structure shows that CEH-37 homeodomain is composed of a flexible N-terminal region and three α-helices with a helix-turn-helix (HTH) DNA binding motif. Data from size-exclusion chromatography and fluorescence spectroscopy reveal that CEH-37 homeodomain interacts strongly with double-stranded C. elegans telomeric DNA. NMR titration experiments identified residues responsible for specific binding to nematode double-stranded telomeric DNA. These results suggest that C. elegans homeodomain protein, CEH-37 could play an important role in telomere function via DNA binding.

  5. Identification of gamma-aminobutyric acid and its binding sites in Caenorhabditis elegans

    SciTech Connect

    Schaeffer, J.M.; Bergstrom, A.R.

    1988-01-01

    Gamma-aminobutyric acid (GABA), glutamate decarboxylase and GABA-transaminase were identified in the nematode Caenorhabditis elegans. The concentration of GABA in C. elegans is approximately 10-fold lower than the concentration of GABA in rat brain. Glutamate decarboxylase and GABA-transaminase, the GABA anabolic and catabolic enzymes, are also present in C. elegans. Crude membrane fractions were prepared from C. elegans and used to study specific (/sup 3/H) GABA binding sites. GABA binds to C. elegans membranes with high affinity and low capacity. Muscimol is a competitive inhibitor of specific GABA binding with a K/sub I/ value of 120 nM. None of the other GABA agonists or antagonists inhibited greater than 40% of the specific GABA binding at concentrations up to 10/sup -4/M. Thirteen spider venoms were examined as possible GABA agonists or antagonists, the venom from Calilena agelenidae inhibits specific GABA binding with a K/sub I/ value of 6 nl/ml. These results suggest that GABA has a physiological role as a neurotransmitter in C. elegans.

  6. Hormetic effect and mechanism of imidazolium-based ionic liquids on the nematode Caenorhabditis elegans.

    PubMed

    Zhu, Chun-Jie; Peng, Yong; Tong, Zhong-Hua; Lu, Li-Ya; Cui, Yin-Hua; Yu, Han-Qing

    2016-08-01

    In the present study, we used Caenorhabditis elegans assay system to investigate in hormetic effects of imidazolium-based bromide Ionic Liquids (ILs) and explored the possible underlying mechanism. Firstly, C. elegans was treated with ILs with different alkyl chain lengths at different concentrations. We found that exposure to ILs at 0.01 mg/L extended the mean lifespan of C. elegans and the ILs with longer alkyl chain showed more obvious effects. To investigate the possible mechanism, the nematodes were exposed to the three ILs at 0.01 mg/L for 2, 5, 7, 9 and 11 days. The levels of reactive oxygen species (ROS) in C. elegans increased significantly when treated for 2 days and then declined gradually compared to those of respective controls as time went on. After exposure for 11 days, the ROS levels and liposuscin accumulation were significantly lower in the treated groups than those of control group. Meanwhile, the expression of aging-related genes sod-5 and daf-16 were both massively up-regulated for the three ILs examined. Our results show that low concentration of ILs exert hormetic effect on C. elegans. ROS generation and expression of aging-related genes may play important roles in the IL-induced hormetic effect on C. elegans. PMID:27209554

  7. The lifespan-extending effects of Nymphaea hybrid root extract in the nematode Caenorhabditis elegans.

    PubMed

    Zhuang, Ziheng; Lv, Ting; Li, Min; Zhang, Yusi; Xue, Ting; Yang, Linsong; Liu, Hui; Zhang, Weiming

    2014-12-01

    Nymphaea hybrid, a water lily from the Nymphaeaceae family, has been found to exhibit some in vivo beneficial effects. In the present study we investigated the lifespan-extending effects of Nymphaea hybrid root extract in the nematode Caenorhabditis elegans. We found that Nymphaea hybrid root extract significantly extended the lifespan of C.elegans and improved its locomotion during aging. Moreover, Nymphaea hybrid root extract increased the resistance of C.elegans to both heat stress and oxidative stress. We found that the ability of Nymphaea hybrid root extract to increase lifespan was independent of its antimicrobial effects and was probably associated with its effects on the reproduction of C.elegans. In addition, the lifespan-extending effects of Nymphaea hybrid root extract were found to be dependent on the insulin/IGF signaling pathway. We also found that total flavones of Nymphaea hybrid could increase survival of C.elegans in both normal and adverse conditions, indicating that total flavones comprise the major fractions with lifespan-extending effects. Therefore, Nymphaea hybrid root extract has lifespan-extending effects in C.elegans and could be developed as a functional food. PMID:25367047

  8. Locomotion and Body Shape Changes of Metabolically Different C.elegans in Fluids with Varying Viscosities

    NASA Astrophysics Data System (ADS)

    Wong, Rachel; Brenowitz, Noah; Shen, Amy

    2010-11-01

    Caenorhabditis elegans (C.elegans) are soil dwelling roundworms that have served as model organisms for studying a multitude of biological and engineering phenomena. On agar, the locomotion of the worm is sinusoidal, while in water, the swimming motion of the worm appears more episodic. The efficiency of the worm locomotion is tested by placing the worm in four fluids with varying viscosities. We quantify the locomotion pattern variations by categorizing the swimming kinematics and shapes of the C.elegans. The locomotion of two mutants C.elegans and a control C.elegans was tested: daf2, nhr49, and N2 Wildtype. The metabolic effects of the worms are evaluated by focusing on the forward swimming velocity, wavelength, amplitude and swimming frequency were compared. Using these measured values, we were able to quantify the efficiency, the speed of propagation of the wave along the body resulting in forward movement (wave velocity), and transverse velocity, defined as the amplitude times the frequency, of the worm locomotion. It was shown that C.elegans has a preferential swimming shape that adapts as the environment changes regardless of its efficiency.

  9. Anti-aging effect of polysaccharide from Bletilla striata on nematode Caenorhabditis elegans

    PubMed Central

    Zhang, Yusi; Lv, Ting; Li, Min; Xue, Ting; Liu, Hui; Zhang, Weiming; Ding, Xiaoyu; Zhuang, Ziheng

    2015-01-01

    Background: Polysaccharide isolated from Bletilla striata, a well-known traditional Chinese medicine (Bletilla striata polysaccharide [BSP]) has been found to play important roles in endothelial cells proliferation, inducible nitric oxide stimulation, wound healing acceleration and other processes. Recent studies found that B. striata has anti-oxidative properties, however, potential anti-aging effects of BSP in whole organisms has not been characterized. Objective: To investigate whether BSP has anti-aging effects on Caenorhabditis elegans. Materials and Methods: After treatment with BSP, the lifespan, locomotion ability, and stress resistance of C. elegans was determined. To provide insight into the underlying mechanism for the anti-aging effect of BSP, we measured its effect on bacterial growth, brood size of C. elegans, and the insulin/insulin-like growth factor (IGF) signaling pathway. Results: After BSP treatment, the lifespan of C. elegans was extended, and its locomotion ability and stress resistance were increased. BSP was found to have no effect on bacterial growth or on reproduction of C. elegans, However, mRNA levels of age-1 and hcf-1 were reduced after BSP treatment. Additionally, we observed that BSP did not extend the lifespan of daf-16 mutant animals. Conclusion: BSP produces an anti-aging effect on C. elegans through the insulin/IGF signaling pathway and holds promise for future development as a functional food. PMID:26246718

  10. A natural odor attraction between lactic acid bacteria and the nematode Caenorhabditis elegans.

    PubMed

    Choi, Jae Im; Yoon, Kyoung-Hye; Subbammal Kalichamy, Saraswathi; Yoon, Sung-Sik; Il Lee, Jin

    2016-03-01

    Animal predators can track prey using their keen sense of smell. The bacteriovorous nematode Caenorhabditis elegans employs sensitive olfactory sensory neurons that express vertebrate-like odor receptors to locate bacteria. C. elegans displays odor-related behaviors such as attraction, aversion and adaptation, but the ecological significance of these behaviors is not known. Using a combination of food microbiology and genetics, we elucidate a possible predator-prey relationship between C. elegans and lactic acid bacteria (LAB) in rotting citrus fruit. LAB produces the volatile odor diacetyl as an oxidized by-product of fermentation in the presence of citrate. We show that C. elegans is attracted to LAB when grown on citrate media or Citrus medica L, commonly known as yuzu, a citrus fruit native to East Asia, and this attraction is mediated by the diacetyl odor receptor, ODR-10. We isolated a wild LAB strain and a wild C. elegans-related nematode from rotten yuzu, and demonstrate that the wild nematode was attracted to the diacetyl produced by LAB. These results not only identify an ecological function for a C. elegans olfactory behavior, but contribute to the growing understanding of ecological relationships between the microbial and metazoan worlds. PMID:26241504

  11. Physiological and Immunological Regulations in Caenorhabditis elegans Infected with Salmonella enterica serovar Typhi.

    PubMed

    Sivamaruthi, Bhagavathi Sundaram; Balamurugan, Krishnaswamy

    2014-03-01

    Studies pertaining to Salmonella enterica serovar Typhimurium infection by utilizing model systems failed to mimic the essential aspects of immunity induced by Salmonella enterica serovar Typhi, as the determinants of innate immunity are distinct. The present study investigated the physiological and innate immune responses of S. Typhi infected Caenorhabditis elegans and also explored the Ty21a mediated immune enhancement in C. elegans. Ty21a is a known live vaccine for typhoidal infection in human beings. Physiological responses of C. elegans infected with S. Typhi assessed by survival and behavioral assays revealed that S. Typhi caused host mortality by persistent infection. However, Ty21a exposure to C. elegans was not harmful. Ty21a pre-exposed C. elegans, exhibited significant resistance against S. Typhi infection. Elevated accumulation of S. Typhi inside the infected host was observed when compared to Ty21a exposures. Transcript analysis of candidate innate immune gene (clec-60, clec-87, lys-7, ilys-3, scl-2, cpr-2, F08G5.6, atf-7, age-1, bec-1 and daf-16) regulations in the host during S. Typhi infection have been assessed through qPCR analysis to understand the activation of immune signaling pathways during S. Typhi infections. Gene silencing approaches confirmed that clec-60 and clec-87 has a major role in the defense system of C. elegans during S. Typhi infection. In conclusion, the study revealed that preconditioning of host with Ty21a protects against subsequent S. Typhi infection. PMID:24426167

  12. Delivery of dietary triglycerides to Caenorhabditis elegans using lipid nanoparticles: Nanoemulsion-based delivery systems.

    PubMed

    Colmenares, Daniel; Sun, Quancai; Shen, Peiyi; Yue, Yiren; McClements, D Julian; Park, Yeonhwa

    2016-07-01

    The nematode Caenorhabditis elegans is a powerful tool for studying food bioactives on specific biochemical pathways. However, many food bioactives are highly hydrophobic with extremely low water-solubilities, thereby making them difficult to study using C. elegans. The purpose of this study was to develop nanoemulsion-based systems to deliver hydrophobic molecules in a form that could be ingested by C. elegans. Optical microscopy showed that oil-in-water nanoemulsions with a range of particle diameters (40-500nm) could be ingested by C. elegans. The amount of lipid ingested depended on the size and concentration of the nanoparticles. Fatty acid analysis showed incorporation of conjugated linoleic acid and there was a significant reduction in the fat levels of C. elegans when they were incubated with nanoemulsions containing conjugated linoleic acid, which suggested that this hydrophobic lipid was successfully delivered to the nematodes. The incorporation of hydrophobic molecules into nanoemulsion based-delivery systems may therefore enable their activities to be studied using C. elegans. PMID:26920318

  13. Identification of Novel Human Genes Evolutionarily Conserved in Caenorhabditis elegans by Comparative Proteomics

    PubMed Central

    Lai, Chun-Hung; Chou, Chang-Yuan; Ch'ang, Lan-Yang; Liu, Chung-Shyan; Lin, Wen-chang

    2000-01-01

    Modern biomedical research greatly benefits from large-scale genome-sequencing projects ranging from studies of viruses, bacteria, and yeast to multicellular organisms, like Caenorhabditis elegans. Comparative genomic studies offer a vast array of prospects for identification and functional annotation of human ortholog genes. We presented a novel comparative proteomic approach for assembling human gene contigs and assisting gene discovery. The C. elegans proteome was used as an alignment template to assist in novel human gene identification from human EST nucleotide databases. Among the available 18,452 C. elegans protein sequences, our results indicate that at least 83% (15,344 sequences) of C. elegans proteome has human homologous genes, with 7,954 records of C. elegans proteins matching known human gene transcripts. Only 11% or less of C. elegans proteome contains nematode-specific genes. We found that the remaining 7,390 sequences might lead to discoveries of novel human genes, and over 150 putative full-length human gene transcripts were assembled upon further database analyses. [The sequence data described in this paper have been submitted to the GenBank data library under accession nos. AF132936–AF132973, AF151799–AF151909, and AF152097.] PMID:10810093

  14. The C. elegans Opa1 homologue EAT-3 is essential for resistance to free radicals.

    PubMed

    Kanazawa, Takayuki; Zappaterra, Mauro D; Hasegawa, Ayako; Wright, Ashley P; Newman-Smith, Erin D; Buttle, Karolyn F; McDonald, Kent; Mannella, Carmen A; van der Bliek, Alexander M

    2008-02-01

    The C. elegans eat-3 gene encodes a mitochondrial dynamin family member homologous to Opa1 in humans and Mgm1 in yeast. We find that mutations in the C. elegans eat-3 locus cause mitochondria to fragment in agreement with the mutant phenotypes observed in yeast and mammalian cells. Electron microscopy shows that the matrices of fragmented mitochondria in eat-3 mutants are divided by inner membrane septae, suggestive of a specific defect in fusion of the mitochondrial inner membrane. In addition, we find that C. elegans eat-3 mutant animals are smaller, grow slower, and have smaller broodsizes than C. elegans mutants with defects in other mitochondrial fission and fusion proteins. Although mammalian Opa1 is antiapoptotic, mutations in the canonical C. elegans cell death genes ced-3 and ced-4 do not suppress the slow growth and small broodsize phenotypes of eat-3 mutants. Instead, the phenotypes of eat-3 mutants are consistent with defects in oxidative phosphorylation. Moreover, eat-3 mutants are hypersensitive to paraquat, which promotes damage by free radicals, and they are sensitive to loss of the mitochondrial superoxide dismutase sod-2. We conclude that free radicals contribute to the pathology of C. elegans eat-3 mutants. PMID:18454199

  15. A Caenorhabditis elegans model for epithelial–neuronal transdifferentiation

    PubMed Central

    Jarriault, Sophie; Schwab, Yannick; Greenwald, Iva

    2008-01-01

    Understanding transdifferentiation—the conversion of one differentiated cell type into another—is important from both basic science and clinical perspectives. In Caenorhabditis elegans, an epithelial cell named Y is initially part of the rectum but later appears to withdraw, migrate, and then become a motor neuron named PDA. Here, we show that this represents a bona fide transdifferentiation event: Y has epithelial hallmarks without detectable neural characteristics, and PDA has no residual epithelial characteristics. Using available mutants and laser microsurgery, we found that transdifferentiation does not depend on fusion with a neighboring cell or require migration of Y away from the rectum, that other rectal epithelial cells are not competent to transdifferentiate, and that transdifferentiation requires the EGL-5 and SEM-4 transcription factors and LIN-12/Notch signaling. Our results establish Y-to-PDA transdifferentiation as a genetically tractable model for deciphering the mechanisms underlying cellular plasticity in vivo. PMID:18308937

  16. Neuropeptide signaling remodels chemosensory circuit composition in Caenorhabditis elegans

    PubMed Central

    Leinwand, Sarah G.; Chalasani, Sreekanth H.

    2013-01-01

    Neural circuits detect environmental changes and drive behavior. The routes of information flow through dense neural networks are dynamic; however, the mechanisms underlying this circuit flexibility are poorly understood. Here, we define a novel, sensory context-dependent and neuropeptide-regulated switch in the composition of a C. elegans salt sensory circuit. The primary salt detectors, ASE sensory neurons, use BLI-4 endoprotease-dependent cleavage to release the insulin-like peptide INS-6 in response to large but not small changes in external salt stimuli. Insulins, signaling through the insulin receptor DAF-2, functionally switch the AWC olfactory sensory neuron into an interneuron in the salt circuit. Animals with disrupted insulin signaling have deficits in salt attraction, suggesting that peptidergic signaling potentiates responses to high salt stimuli, which may promote ion homeostasis. Our results show that sensory context and neuropeptide signaling modify neural networks and suggest general mechanisms for generating flexible behavioral outputs by modulating neural circuit composition. PMID:24013594

  17. How Does C. elegans Respond to Altered Gravity?

    NASA Technical Reports Server (NTRS)

    Conley, Catharine A.; Udranszky, Ingrid; Hoffman, David; Kim, Stuart K.

    2001-01-01

    All organisms on Earth have evolved at unit gravity (1xG), and thus are probably adapted to function optimally at 1xG. However, with the advent of space exploration, it has been shown that organisms are capable of surviving at much less than 1xG, as well as at greater than 1xG. Organisms subjected to increased G levels exhibit alterations in physiological processes that compensate for novel environmental stresses, such as increased weight and density-driven sedimentation. These physiological adaptations illustrate the plasticity of organisms when presented with environmental conditions in which they could not possibly have evolved. Investigating the mechanism(s) behind these adaptations may uncover biological pathways that have not previously been identified. An easily-cultured and well-studied organism, such as C. elegans, would be a desirable model system for these studies. Additional information is contained in the original extended abstract.

  18. A size threshold governs Caenorhabditis elegans developmental progression.

    PubMed

    Uppaluri, Sravanti; Brangwynne, Clifford P

    2015-08-22

    The growth of organisms from humans to bacteria is affected by environmental conditions. However, mechanisms governing growth and size control are not well understood, particularly in the context of changes in food availability in developing multicellular organisms. Here, we use a novel microfluidic platform to study the impact of diet on the growth and development of the nematode Caenorhabditis elegans. This device allows us to observe individual worms throughout larval development, quantify their growth as well as pinpoint the moulting transitions marking successive developmental stages. Under conditions of low food availability, worms grow very slowly, but do not moult until they have achieved a threshold size. The time spent in larval stages can be extended by over an order of magnitude, in agreement with a simple threshold size model. Thus, a critical worm size appears to trigger developmental progression, and may contribute to prolonged lifespan under dietary restriction. PMID:26290076

  19. Engineering the Caenorhabditis elegans genome with CRISPR/Cas9.

    PubMed

    Waaijers, Selma; Boxem, Mike

    2014-08-01

    The development in early 2013 of CRISPR/Cas9-based genome engineering promises to dramatically advance our ability to alter the genomes of model systems at will. A single, easily produced targeting RNA guides the Cas9 endonuclease to a specific DNA sequence where it creates a double strand break. Imprecise repair of the break can yield mutations, while homologous recombination with a repair template can be used to effect specific changes to the genome. The tremendous potential of this system led several groups to independently adapt it for use in Caenorhabditiselegans, where it was successfully used to generate mutations and to create tailored genome changes through homologous recombination. Here, we review the different approaches taken to adapt CRISPR/Cas9 for C. elegans, and provide practical guidelines for CRISPR/Cas9-based genome engineering. PMID:24685391

  20. Flow-Based Network Analysis of the Caenorhabditis elegans Connectome.

    PubMed

    Bacik, Karol A; Schaub, Michael T; Beguerisse-Díaz, Mariano; Billeh, Yazan N; Barahona, Mauricio

    2016-08-01

    We exploit flow propagation on the directed neuronal network of the nematode C. elegans to reveal dynamically relevant features of its connectome. We find flow-based groupings of neurons at different levels of granularity, which we relate to functional and anatomical constituents of its nervous system. A systematic in silico evaluation of the full set of single and double neuron ablations is used to identify deletions that induce the most severe disruptions of the multi-resolution flow structure. Such ablations are linked to functionally relevant neurons, and suggest potential candidates for further in vivo investigation. In addition, we use the directional patterns of incoming and outgoing network flows at all scales to identify flow profiles for the neurons in the connectome, without pre-imposing a priori categories. The four flow roles identified are linked to signal propagation motivated by biological input-response scenarios. PMID:27494178

  1. Flow-Based Network Analysis of the Caenorhabditis elegans Connectome

    PubMed Central

    Bacik, Karol A.; Schaub, Michael T.; Billeh, Yazan N.; Barahona, Mauricio

    2016-01-01

    We exploit flow propagation on the directed neuronal network of the nematode C. elegans to reveal dynamically relevant features of its connectome. We find flow-based groupings of neurons at different levels of granularity, which we relate to functional and anatomical constituents of its nervous system. A systematic in silico evaluation of the full set of single and double neuron ablations is used to identify deletions that induce the most severe disruptions of the multi-resolution flow structure. Such ablations are linked to functionally relevant neurons, and suggest potential candidates for further in vivo investigation. In addition, we use the directional patterns of incoming and outgoing network flows at all scales to identify flow profiles for the neurons in the connectome, without pre-imposing a priori categories. The four flow roles identified are linked to signal propagation motivated by biological input-response scenarios. PMID:27494178

  2. An Engineering Approach to Extending Lifespan in C. elegans

    PubMed Central

    Sagi, Dror; Kim, Stuart K.

    2012-01-01

    We have taken an engineering approach to extending the lifespan of Caenorhabditis elegans. Aging stands out as a complex trait, because events that occur in old animals are not under strong natural selection. As a result, lifespan can be lengthened rationally using bioengineering to modulate gene expression or to add exogenous components. Here, we engineered longer lifespan by expressing genes from zebrafish encoding molecular functions not normally present in worms. Additionally, we extended lifespan by increasing the activity of four endogenous worm aging pathways. Next, we used a modular approach to extend lifespan by combining components. Finally, we used cell- and worm-based assays to analyze changes in cell physiology and as a rapid means to evaluate whether multi-component transgenic lines were likely to have extended longevity. Using engineering to add novel functions and to tune endogenous functions provides a new framework for lifespan extension that goes beyond the constraints of the worm genome. PMID:22737090

  3. Selection and maintenance of androdioecy in Caenorhabditis elegans.

    PubMed Central

    Stewart, Andrew D; Phillips, Patrick C

    2002-01-01

    Caenorhabditis elegans is an androdioecious nematode composed of selfing hermaphrodites and rare males. A model of male maintenance demonstrates that selfing rates in hermaphrodites cannot be too high or else the frequency of males will be driven down to the rate of spontaneous nondisjunction of the X chromosome. After their outcrossing ability is assessed, males are found to skirt the frequency range in which they would be maintained. When male maintenance is directly assessed by elevating male frequency and observing the frequency change through time, males are gradually eliminated from the population. Males, therefore, appear to reproduce at a rate just below that necessary for them to be maintained. Populations polymorphic for a mutation (fog-2) that effectively changes hermaphrodites into females demonstrate that there is strong selection against dioecy. Factors such as variation in male mating ability and inbreeding depression could potentially lead to the long-term maintenance of males. PMID:11901115

  4. A quantifiably complete repertoire of C. elegans locomotion

    NASA Astrophysics Data System (ADS)

    Brown, Andre; Schwarz, Roland; Branicky, Robyn; Schafer, William

    2014-03-01

    Visible phenotypes have played a critical role in understanding the molecular basis of behaviour in model organisms. However, most current descriptions of behaviour are based on manually identified events or a limited set of quantitative parameters. Here we report an extension of the concept of behavioural motifs to exhaustively catalogue C. elegans locomotion and derive a repertoire that is quantifiably complete. A repertoire learned for spontaneous behaviour in wild-type worms can be used to fit data from mutants or worms in different environmental conditions and provides a sensitive measure of phenotypic similarity. Repertoire comparison can also be used to assess inter-individual variation and the compositionality of behaviour, that is, the extent to which behavioural adaptation involves the creation of novel repertoire elements or the reuse of existing elements in novel sequences. Repertoire derivation is general, so that given a representation of posture, our approach will apply to other organisms.

  5. Redefining the role of syndecans in C. elegans biology.

    PubMed

    Gopal, Sandeep; Couchman, John; Pocock, Roger

    2016-01-01

    Cytosolic calcium is an important factor during fertilization, development and differentiation. Hence, the control of cytosolic calcium levels has been studied extensively for several decades. Numerous calcium channels have been identified and their mechanism of action elucidated. However, the mode of calcium channel regulation remains elusive. Here we discuss our recent findings regarding the role of syndecans in the regulation of cytosolic calcium levels. Syndecans are transmembrane proteoglycans present in both vertebrates and invertebrates that interact with extracellular ligands resulting in the activation of several downstream signaling pathways. We identified a previously unappreciated role of syndecans in cytosolic calcium regulation in mammals that is conserved in C. elegans. We concluded that calcium regulation is the basic, evolutionarily conserved role for syndecans, which enables them to be integral for multiple cellular functions. PMID:27073736

  6. Manganese-induced Neurotoxicity: From C. elegans to Humans

    PubMed Central

    Chen, Pan; Chakraborty, Sudipta; Peres, Tanara V.; Bowman, Aaron B.; Aschner, Michael

    2014-01-01

    Manganese (Mn) is one of the most abundant metals on the earth. It is required for normal cellular activities, but overexposure leads to toxicity. Neurons are more susceptible to Mn-induced toxicity than other cells, and accumulation of Mn in the brain results in Manganism that presents with Parkinson's disease (PD)-like symptoms. In the last decade, a number of Mn transporters have been identified, which improves our understanding of Mn transport in and out of cells. However, the mechanism of Mn-induced neurotoxicity is only partially uncovered, with further research needed to explore the whole picture of Mn-induced toxicity. In this review, we will address recent progress in Mn-induced neurotoxicity from C. elegans to humans, and explore future directions that will help understand the mechanisms of its neurotoxicity. PMID:25893090

  7. Regulatory analysis of the C. elegans genome with spatiotemporal resolution

    PubMed Central

    Araya, Carlos L.; Kawli, Trupti; Kundaje, Anshul; Jiang, Lixia; Wu, Beijing; Vafeados, Dionne; Terrell, Robert; Weissdepp, Peter; Gevirtzman, Louis; Mace, Daniel; Niu, Wei; Boyle, Alan P.; Xie, Dan; Ma, Lijia; Murray, John I.; Reinke, Valerie; Waterston, Robert H.; Snyder, Michael

    2015-01-01

    Summary Discovering the structure and dynamics of transcriptional regulatory events in the genome with cellular and temporal resolution is crucial to understanding the regulatory underpinnings of development and disease. We determined the genomic distribution of binding sites for 92 transcription factors (TFs) and regulatory proteins across multiple stages of C. elegans development by performing 241 ChIP-seq experiments. Integrating regulatory binding and cellular-resolution expression data yielded a spatiotemporally-resolved metazoan TF binding map. Using this map, we explore developmental regulatory circuits that encode combinatorial logic at the levels of co-binding and co-expression of TFs, characterizing (1) the genomic coverage and clustering of regulatory binding, (2) the binding preferences of and biological processes regulated by TFs, (3) the global TF co-associations and genomic subdomains that suggest shared patterns of regulation, and (4) key TFs and TF co-associations for fate specification of individual lineages and cell-types. PMID:25164749

  8. Kinetics and specificity of paternal mitochondrial elimination in Caenorhabditis elegans.

    PubMed

    Wang, Yang; Zhang, Yi; Chen, Lianwan; Liang, Qian; Yin, Xiao-Ming; Miao, Long; Kang, Byung-Ho; Xue, Ding

    2016-01-01

    In most eukaryotes, mitochondria are inherited maternally. The autophagy process is critical for paternal mitochondrial elimination (PME) in Caenorhabditis elegans, but how paternal mitochondria, but not maternal mitochondria, are selectively targeted for degradation is poorly understood. Here we report that mitochondrial dynamics have a profound effect on PME. A defect in fission of paternal mitochondria delays PME, whereas a defect in fusion of paternal mitochondria accelerates PME. Surprisingly, a defect in maternal mitochondrial fusion delays PME, which is reversed by a fission defect in maternal mitochondria or by increasing maternal mitochondrial membrane potential using oligomycin. Electron microscopy and tomography analyses reveal that a proportion of maternal mitochondria are compromised when they fail to fuse normally, leading to their competition for the autophagy machinery with damaged paternal mitochondria and delayed PME. Our study indicates that mitochondrial dynamics play a critical role in regulating both the kinetics and the specificity of PME. PMID:27581092

  9. Radiation-induced gene expression in the nematode Caenorhabditis elegans

    NASA Technical Reports Server (NTRS)

    Nelson, Gregory A.; Jones, Tamako A.; Chesnut, Aaron; Smith, Anna L.

    2002-01-01

    We used the nematode C. elegans to characterize the genotoxic and cytotoxic effects of ionizing radiation in a simple animal model emphasizing the unique effects of charged particle radiation. Here we demonstrate by RT-PCR differential display and whole genome microarray hybridization experiments that gamma rays, accelerated protons and iron ions at the same physical dose lead to unique transcription profiles. 599 of 17871 genes analyzed (3.4%) showed differential expression 3 hrs after exposure to 3 Gy of radiation. 193 were up-regulated, 406 were down-regulated and 90% were affected only by a single species of radiation. A novel statistical clustering technique identified the regulatory relationships between the radiation-modulated genes and showed that genes affected by each radiation species were associated with unique regulatory clusters. This suggests that independent homeostatic mechanisms are activated in response to radiation exposure as a function of track structure or ionization density.

  10. Alternative meiotic chromatid segregation in the holocentric plant Luzula elegans

    PubMed Central

    Heckmann, Stefan; Jankowska, Maja; Schubert, Veit; Kumke, Katrin; Ma, Wei; Houben, Andreas

    2014-01-01

    Holocentric chromosomes occur in a number of independent eukaryotic lineages. They form holokinetic kinetochores along the entire poleward chromatid surfaces, and owing to this alternative chromosome structure, species with holocentric chromosomes cannot use the two-step loss of cohesion during meiosis typical for monocentric chromosomes. Here we show that the plant Luzula elegans maintains a holocentric chromosome architecture and behaviour throughout meiosis, and in contrast to monopolar sister centromere orientation, the unfused holokinetic sister centromeres behave as two distinct functional units during meiosis I, resulting in sister chromatid separation. Homologous non-sister chromatids remain terminally linked after metaphase I, by satellite DNA-enriched chromatin threads, until metaphase II. They then separate at anaphase II. Thus, an inverted sequence of meiotic sister chromatid segregation occurs. This alternative meiotic process is most likely one possible adaptation to handle a holocentric chromosome architecture and behaviour during meiosis. PMID:25296379

  11. Radiosensitivity Parameters For Lethal Mutagenesis In Caenorhabditis Elegans

    SciTech Connect

    Cucinotta, F.A.; Wilson, J.W.; Katz, R.

    1994-01-01

    For the first time track structure theory has been applied to radiobiological effects in a living organism. Data for lethal mutagenesis in Caenorhabditis elegans, obtained after irradiation with nine different types of ions of atomic number 1-57 and gamma rays have yielded radiosensitivity parameters (E{sub 0}, sigma{sub 0}, Kappa, m = 68 Gy, 2.5 x 10(exp {minus}9) cm (exp 2), 750, 2) comparable with those found for the transformation of C3HT10 1/2 cells (180 Gy, 1.15 x 10(exp {minus}10) cm(exp 2), 750, 2) but remote from those (E{sub 0} and sigma{sub 0} = approx. 2 Gy, approx. 5 x 10(exp {minus}7) cm(exp 2)) for mammalian cell survival.

  12. Controlling neural activity in Caenorhabditis elegans to evoke chemotactic behavior

    NASA Astrophysics Data System (ADS)

    Kocabas, Askin; Shen, Ching-Han; Guo, Zengcai V.; Ramanathan, Sharad

    2013-03-01

    Animals locate and track chemoattractive gradients in the environment to find food. With its simple nervous system, Caenorhabditis elegans is a good model system in which to understand how the dynamics of neural activity control this search behavior. To understand how the activity in its interneurons coordinate different motor programs to lead the animal to food, here we used optogenetics and new optical tools to manipulate neural activity directly in freely moving animals to evoke chemotactic behavior. By deducing the classes of activity patterns triggered during chemotaxis and exciting individual neurons with these patterns, we identified interneurons that control the essential locomotory programs for this behavior. Notably, we discovered that controlling the dynamics of activity in just one interneuron pair was sufficient to force the animal to locate, turn towards and track virtual light gradients.

  13. Mechanical systems biology of C. elegans touch sensation

    PubMed Central

    Krieg, Michael; Dunn, Alex; Goodman, Miriam B.

    2015-01-01

    The sense of touch informs us of the physical properties of our surroundings and is a critical aspect of communication. Before touches are perceived, mechanical signals are transmitted quickly and reliably from the skin’s surface to mechano-electrical transduction channels embedded within specialized sensory neurons. We are just beginning to understand how soft tissues participate in force transmission and how they are deformed. Here, we review empirical and theoretical studies of single molecules and molecular ensembles thought to be involved in mechanotransmission and apply the concepts emerging from this work to the sense of touch. We focus on the nematode Caenorhabditis elegans as a well-studied model for touch sensation in which mechanics can be studied on the molecular, cellular, and systems level. Finally, we conclude that force transmission is an emergent property of macromolecular cellular structures that mutually stabilize one another. PMID:25597279

  14. Neuropeptide signaling remodels chemosensory circuit composition in Caenorhabditis elegans.

    PubMed

    Leinwand, Sarah G; Chalasani, Sreekanth H

    2013-10-01

    Neural circuits detect environmental changes and drive behavior. The routes of information flow through dense neural networks are dynamic, but the mechanisms underlying this circuit flexibility are poorly understood. Here, we define a sensory context-dependent and neuropeptide-regulated switch in the composition of a C. elegans salt sensory circuit. The primary salt detectors, ASE sensory neurons, used BLI-4 endoprotease-dependent cleavage to release the insulin-like peptide INS-6 in response to large, but not small, changes in external salt stimuli. Insulins, signaling through the insulin receptor DAF-2, functionally switched the AWC olfactory sensory neuron into an interneuron in the salt circuit. Worms with disrupted insulin signaling had deficits in salt attraction, suggesting that peptidergic signaling potentiates responses to high salt stimuli, which may promote ion homeostasis. Our results indicate that sensory context and neuropeptide signaling modify neural networks and suggest general mechanisms for generating flexible behavioral outputs by modulating neural circuit composition. PMID:24013594

  15. Single copy insertion of transgenes in C. elegans

    PubMed Central

    Frøkjær-Jensen, Christian; Davis, M. Wayne; Hopkins, Christopher E.; Newman, Blake; Thummel, Jason M.; Olesen, Søren-Peter; Grunnet, Morten; Jorgensen, Erik M.

    2009-01-01

    Currently transgenes in C. elegans are generated by injecting DNA into the germline. The DNA assembles into a semi-stable extrachromosomal array composed of many copies of injected DNA. These transgenes are typically overexpressed in somatic cells and silenced in the germline. We have developed a method called MosSCI (Mos1-mediated Single Copy Insertion) that inserts a single copy of a transgene into a defined site. Mobilization of a Mos1 transposon generates a double strand break in non-coding DNA. The break is repaired by copying DNA from an extrachromosomal template into the chromosomal site. Homozygous single copy insertions can be obtained in less than two weeks by injecting approximately twenty animals. We have successfully inserted transgenes as long as 9 kb and verified that single copies are inserted at the targeted site. Single copy transgenes are expressed at endogenous levels and can be expressed in the female and male germlines. PMID:18953339

  16. The infrabuccal pellet piles of fungus-growing ants.

    PubMed

    Little, Ainslie E F; Murakami, Takahiro; Mueller, Ulrich G; Currie, Cameron R

    2003-12-01

    Fungus-growing ants (Attini) live in an obligate mutualism with the fungi they cultivate for food. Because of the obligate nature of this relationship, the success of the ants is directly dependent on their ability to grow healthy fungus gardens. Attine ants have evolved complex disease management strategies to reduce their garden's exposure to potential parasitic microbes, to prevent the establishment of infection in their gardens, and to remove infected garden sections. The infrabuccal pocket, a filtering device located in the oral cavity of all ants, is an integral part of the mechanisms that leaf-cutter ants use to prevent the invasion and spread of general microbial parasites and the specific fungal-garden parasite Escovopsis. Fungus-growing ants carefully groom their garden, collecting general debris and pathogenic spores of Escovopsis in their infrabuccal pocket, the contents of which are later expelled in dump chambers inside the nest or externally. In this study we examined how a phylogenetically diverse collection of attine ants treat their infrabuccal pellets. Unlike leaf-cutters that deposit their infrabuccal pellets directly in refuse piles, ants of the more basal attine lineages stack their infrabuccal pellets in piles located close to their gardens, and a separate caste of workers is devoted to the construction, management, and eventual disposal of these piles. PMID:14676952

  17. Relationships between Swiss needle cast and ectomycorrhizal fungus diversity.

    PubMed

    Luoma, Daniel L; Eberhart, Joyce L

    2014-01-01

    Swiss needle cast (SNC) is a disease specific to Douglas-fir (Pseudotsuga menziesii) caused by the ascomycete Phaeocryptopus gaeumannii. Here we examine characteristics of the EM fungus community that are potentially useful in predictive models that would monitor forest health. We found that mean EM density (number of colonized root tips/soil core) varied nearly 10-fold among sites of varying levels of SNC, while mean EM fungus species richness (number of species/soil core) varied by about 2.5 times. Strong relationships were found between EM and SNC parameters: EM species richness was positively correlated with both Douglas-fir needle retention (R(2) = 0.93) and EM density (R(2) = 0.65); EM density also was significantly correlated with Douglas-fir needle retention (R(2) = 0.70). These simple characteristics of the EM fungus community could be used to monitor forest health and generate predictive models of site suitability for Douglas-fir. Based on previous findings that normally common EM types were reduced in frequency on sites with severe SNC, we also hypothesized that some EM fungi would be stress tolerant-dominant species. Instead, we found that various fungi were able to form EM with the stressed trees, but none were consistently dominant across samples in the severely diseased areas. PMID:24895426

  18. Solubilization of lignin by the ruminal anaerobic fungus Neocallimastix patriciarum.

    PubMed Central

    McSweeney, C S; Dulieu, A; Katayama, Y; Lowry, J B

    1994-01-01

    The ability of the ruminal anaerobic phycomycete Neocallimastix patriciarum to digest model lignin compounds and lignified structures in plant material was studied in batch culture. The fungus did not degrade or transform model lignin compounds that were representative of the predominant intermonomer linkages in lignin, nor did it solubilize acid detergent lignin that had been isolated from spear grass. In a stem fraction of sorghum, 33.6% of lignin was apparently solubilized by the fungus. Solubilization of ester- and either-linked phenolics accounted for 9.2% of the lignin released. The amounts of free phenolic acids detected in culture fluid were equivalent to the apparent loss of ester-linked phenolics from the sorghum substrate. However, the fungus was unable to cleave the ether bond in hydroxycinnamic acid bridges that cross-link lignin and polysaccharide. It is suggested that the majority of the solubilized lignin fraction was a lignin carbohydrate complex containing ether-linked hydroxycinnamic acids. The lignin carbohydrate complex was probably solubilized through dissolution of xylan in the lignin-xylan matrix rather than by lignin depolymerization. PMID:8085834

  19. Efficient xylose fermentation by the brown rot fungus Neolentinus lepideus.

    PubMed

    Okamoto, Kenji; Kanawaku, Ryuichi; Masumoto, Masaru; Yanase, Hideshi

    2012-02-10

    The efficient production of bioethanol on an industrial scale requires the use of renewable lignocellulosic biomass as a starting material. A limiting factor in developing efficient processes is identifying microorganisms that are able to effectively ferment xylose, the major pentose sugar found in hemicellulose, and break down carbohydrate polymers without pre-treatment steps. Here, a basidiomycete brown rot fungus was isolated as a new biocatalyst with unprecedented fermentability, as it was capable of converting not only the 6-carbon sugars constituting cellulose, but also the major 5-carbon sugar xylose in hemicelluloses, to ethanol. The fungus was identified as Neolentinus lepideus and was capable of assimilating and fermenting xylose to ethanol in yields of 0.30, 0.33, and 0.34 g of ethanol per g of xylose consumed under aerobic, oxygen-limited, and anaerobic conditions, respectively. A small amount of xylitol was detected as the major by-product of xylose metabolism. N. lepideus produced ethanol from glucose, mannose, galactose, cellobiose, maltose, and lactose with yields ranging from 0.34 to 0.38 g ethanol per g sugar consumed, and also exhibited relatively favorable conversion of non-pretreated starch, xylan, and wheat bran. These results suggest that N. lepideus is a promising candidate for cost-effective and environmentally friendly ethanol production from lignocellulosic biomass. To our knowledge, this is the first report on efficient ethanol fermentation from various carbohydrates, including xylose, by a naturally occurring brown rot fungus. PMID:22226194

  20. Organization of the synaptonemal complex during meiosis in Caenorhabditis elegans.

    PubMed

    Schild-Prüfert, Kristina; Saito, Takamune T; Smolikov, Sarit; Gu, Yanjie; Hincapie, Marina; Hill, David E; Vidal, Marc; McDonald, Kent; Colaiácovo, Monica P

    2011-10-01

    Four different SYP proteins (SYP-1, SYP-2, SYP-3, and SYP-4) have been proposed to form the central region of the synaptonemal complex (SC) thereby bridging the axes of paired meiotic chromosomes in Caenorhabditis elegans. Their interdependent localization suggests that they may interact within the SC. Our studies reveal for the first time how these SYP proteins are organized in the central region of the SC. Yeast two-hybrid and co-immunoprecipitation studies show that SYP-1 is the only SYP protein that is capable of homotypic interactions, and is able to interact with both SYP-2 and SYP-3 directly, whereas SYP-2 and SYP-3 do not seem to interact with each other. Specifically, the coiled-coil domain of SYP-1 is required both for its homotypic interactions and its interaction with the C-terminal domain of SYP-2. Meanwhile, SYP-3 interacts with the C-terminal end of SYP-1 via its N-terminal domain. Immunoelectron microscopy analysis provides insight into the orientation of these proteins within the SC. While the C-terminal domain of SYP-3 localizes in close proximity to the chromosome axes, the N-terminal domains of both SYP-1 and SYP-4, as well as the C-terminal domain of SYP-2, are located in the middle of the SC. Taking into account the different sizes of these proteins, their interaction abilities, and their orientation within the SC, we propose a model of how the SYP proteins link the homologous axes to provide the conserved structure and width of the SC in C. elegans. PMID:21840865

  1. Organization of the Synaptonemal Complex During Meiosis in Caenorhabditis elegans

    PubMed Central

    Schild-Prüfert, Kristina; Saito, Takamune T.; Smolikov, Sarit; Gu, Yanjie; Hincapie, Marina; Hill, David E.; Vidal, Marc; McDonald, Kent; Colaiácovo, Monica P.

    2011-01-01

    Four different SYP proteins (SYP-1, SYP-2, SYP-3, and SYP-4) have been proposed to form the central region of the synaptonemal complex (SC) thereby bridging the axes of paired meiotic chromosomes in Caenorhabditis elegans. Their interdependent localization suggests that they may interact within the SC. Our studies reveal for the first time how these SYP proteins are organized in the central region of the SC. Yeast two-hybrid and co-immunoprecipitation studies show that SYP-1 is the only SYP protein that is capable of homotypic interactions, and is able to interact with both SYP-2 and SYP-3 directly, whereas SYP-2 and SYP-3 do not seem to interact with each other. Specifically, the coiled-coil domain of SYP-1 is required both for its homotypic interactions and its interaction with the C-terminal domain of SYP-2. Meanwhile, SYP-3 interacts with the C-terminal end of SYP-1 via its N-terminal domain. Immunoelectron microscopy analysis provides insight into the orientation of these proteins within the SC. While the C-terminal domain of SYP-3 localizes in close proximity to the chromosome axes, the N-terminal domains of both SYP-1 and SYP-4, as well as the C-terminal domain of SYP-2, are located in the middle of the SC. Taking into account the different sizes of these proteins, their interaction abilities, and their orientation within the SC, we propose a model of how the SYP proteins link the homologous axes to provide the conserved structure and width of the SC in C. elegans. PMID:21840865

  2. Mechanisms of plasticity in a Caenorhabditis elegans mechanosensory circuit

    PubMed Central

    Bozorgmehr, Tahereh; Ardiel, Evan L.; McEwan, Andrea H.; Rankin, Catharine H.

    2012-01-01

    Despite having a small nervous system (302 neurons) and relatively short lifespan (14–21 days), the nematode Caenorhabditis elegans has a substantial ability to change its behavior in response to experience. The behavior discussed here is the tap withdrawal response, whereby the worm crawls backwards a brief distance in response to a non-localized mechanosensory stimulus from a tap to the side of the Petri plate within which it lives. The neural circuit that underlies this behavior is primarily made up of five sensory neurons and four pairs of interneurons. In this review we describe two classes of mechanosensory plasticity: adult learning and memory and experience dependent changes during development. As worms develop through young adult and adult stages there is a shift toward deeper habituation of response probability that is likely the result of changes in sensitivity to stimulus intensity. Adult worms show short- intermediate- and long-term habituation as well as context dependent habituation. Short-term habituation requires glutamate signaling and auto-phosphorylation of voltage-dependent potassium channels and is modulated by dopamine signaling in the mechanosensory neurons. Long-term memory (LTM) for habituation is mediated by down-regulation of expression of an AMPA-type glutamate receptor subunit. Intermediate memory involves an increase in release of an inhibitory neuropeptide. Depriving larval worms of mechanosensory stimulation early in development leads to fewer synaptic vesicles in the mechanosensory neurons and lower levels of an AMPA-type glutamate receptor subunit in the interneurons. Overall, the mechanosensory system of C. elegans shows a great deal of experience dependent plasticity both during development and as an adult. The simplest form of learning, habituation, is not so simple and is mediated and/or modulated by a number of different processes, some of which we are beginning to understand. PMID:23986713

  3. Isoflurane Selectively Inhibits Distal Mitochondrial Complex I in Caenorhabditis Elegans

    PubMed Central

    Kayser, Ernst-Bernhard; Suthammarak, Wichit; Morgan, Phil G.; Sedensky, Margaret M.

    2011-01-01

    BACKGROUND Complex I of the electron transport chain (ETC) is a possible target of volatile anesthetics (VAs). Complex I enzymatic activities are inhibited by VAs, and dysfunction of complex I can lead to hypersensitivity to VAs in worms and in people. Mutant analysis in Caenorhabditis (C.) elegans suggests that VAs may specifically interfere with complex I function at the binding site for its substrate ubiquinone. We hypothesized that isoflurane inhibits electron transport by competing with ubiquinone for binding to complex I. METHODS Wildtype and mutant C. elegans were used to study the effects of isoflurane on isolated mitochondria. Enzymatic activities of the ETC were assayed and dose-response curves determined using established techniques. Two-dimensional native gels of mitochondrial proteins were performed after exposure of mitochondria to isoflurane. RESULTS Complex I is the most sensitive component of the ETC to isoflurane inhibition; however the proximal portion of complex I (the flavoprotein) is relatively insensitive to isoflurane. Isoflurane and quinone do not compete for a common binding site on complex I. The absolute rate of complex I enzymatic activity in vitro does not predict immobilization of the animal by isoflurane. Isoflurane had no measurable effect on stability of mitochondrial supercomplexes. Reduction of ubiquinone by complex I displayed positive cooperative kinetics not disrupted by isoflurane. CONCLUSIONS Isoflurane directly inhibits complex I at a site distal to the flavoprotein subcomplex. However, we have excluded our original hypothesis that isoflurane and ubiquinone compete for a common hydrophobic binding site on complex I. In addition, immobilization of the nematode by isoflurane is not due to limiting absolute amounts of complex I electron transport as measured in isolated mitochondria. PMID:21467554

  4. IgCAMs redundantly control axon navigation in Caenorhabditis elegans

    PubMed Central

    Schwarz, Valentin; Pan, Jie; Voltmer-Irsch, Susanne; Hutter, Harald

    2009-01-01

    Background Cell adhesion molecules of the immunoglobulin superfamily (IgCAMs) form one of the largest and most diverse families of adhesion molecules and receptors in the nervous system. Many members of this family mediate contact and communication among neurons during development. The Caenorhabditis elegans genome contains a comparatively small number of IgCAMs, most of which are evolutionarily conserved and found across all animal phyla. Only some of these have been functionally characterized so far. Results We systematically analyzed previously uncharacterized IgCAMs in C. elegans. Green fluorescent protein reporter constructs of 12 IgCAMs revealed that expression generally is not confined to a single tissue and that all tissues express at least one of the IgCAMs. Most IgCAMs were expressed in neurons. Within the nervous system significant overlap in expression was found in central components of the motor circuit, in particular the command interneurons, ventral cord motoneurons as well as motoneurons innervating head muscles. Sensory neurons are underrepresented among the cells expressing these IgCAMs. We isolated mutations for eight of the genes showing neuronal expression. Phenotypic analysis of single mutants revealed limited neuronal defects, in particular axon navigation defects in some of the mutants. Systematic genetic interaction studies uncovered two cases of functional overlap among three and four genes, respectively. A strain combining mutations in all eight genes is viable and shows no additional defects in the neurons that were analyzed, suggesting that genetic interactions among those genes are limited. Conclusion Genetic interactions involving multiple IgCAMs affecting axon outgrowth demonstrate functional overlap among IgCAMs during nervous system development. PMID:19341471

  5. The nematode Caenorhabditis elegans as a tool to predict chemical activity on mammalian development and identify mechanisms influencing toxicological outcome

    PubMed Central

    Harlow, Philippa H.; Perry, Simon J.; Widdison, Stephanie; Daniels, Shannon; Bondo, Eddie; Lamberth, Clemens; Currie, Richard A.; Flemming, Anthony J.

    2016-01-01

    To determine whether a C. elegans bioassay could predict mammalian developmental activity, we selected diverse compounds known and known not to elicit such activity and measured their effect on C. elegans egg viability. 89% of compounds that reduced C. elegans egg viability also had mammalian developmental activity. Conversely only 25% of compounds found not to reduce egg viability in C. elegans were also inactive in mammals. We conclude that the C. elegans egg viability assay is an accurate positive predictor, but an inaccurate negative predictor, of mammalian developmental activity. We then evaluated C. elegans as a tool to identify mechanisms affecting toxicological outcomes among related compounds. The difference in developmental activity of structurally related fungicides in C. elegans correlated with their rate of metabolism. Knockdown of the cytochrome P450s cyp-35A3 and cyp-35A4 increased the toxicity to C. elegans of the least developmentally active compounds to the level of the most developmentally active. This indicated that these P450s were involved in the greater rate of metabolism of the less toxic of these compounds. We conclude that C. elegans based approaches can predict mammalian developmental activity and can yield plausible hypotheses for factors affecting the biological potency of compounds in mammals. PMID:26987796

  6. The origin of the attine ant-fungus mutualism.

    PubMed

    Mueller, U G; Schultz, T R; Currie, C R; Adams, R M; Malloch, D

    2001-06-01

    Cultivation of fungus for food originated about 45-65 million years ago in the ancestor of fungus-growing ants (Formicidae, tribe Attini), representing an evolutionary transition from the life of a hunter-gatherer of arthropod prey, nectar, and other plant juices, to the life of a farmer subsisting on cultivated fungi. Seven hypotheses have been suggested for the origin of attine fungiculture, each differing with respect to the substrate used by the ancestral attine ants for fungal cultivation. Phylogenetic information on the cultivated fungi, in conjunction with information on the nesting biology of extant attine ants and their presumed closest relatives, reveal that the attine ancestors probably did not encounter their cultivars-to-be in seed stores (von Ihering 1894), in rotting wood (Forel 1902), as mycorrhizae (Garling 1979), on arthropod corpses (von Ihering 1894) or ant faeces in nest middens (Wheeler 1907). Rather, the attine ant-fungus mutualism probably arose from adventitious interactions with fungi that grew on walls of nests built in leaf litter (Emery 1899), or from a system of fungal myrmecochory in which specialized fungi relied on ants for dispersal (Bailey 1920) and in which the ants fortuitously vectored these fungi from parent to offspring nests prior to a true fungicultural stage. Reliance on fungi as a dominant food source has evolved only twice in ants: first in the attine ants, and second in some ant species in the solenopsidine genus Megalomyrmex that either coexist as trophic parasites in gardens of attine hosts or aggressively usurp gardens from them. All other known ant-fungus associations are either adventitious or have nonnutritional functions (e.g., strengthening of carton-walls in ant nests). There exist no unambiguous reports of facultative mycophagy in ants, but such trophic ant-fungus interactions would most likely occur underground or in leaf litter and thus escape easy observation. Indirect evidence of fungivory can be deduced

  7. Isolation and characterization of a β-glucuronide of hydroxylated SARM S1 produced using a combination of biotransformation and chemical oxidation.

    PubMed

    Rydevik, Axel; Lagojda, Andreas; Thevis, Mario; Bondesson, Ulf; Hedeland, Mikael

    2014-09-01

    In this study, using mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy, it has been confirmed that biotransformation with the fungus Cunninghamella elegans combined with chemical oxidation with the free radical tetramethylpiperidinyl-1-oxy (TEMPO) can produce drug glucuronides of β-configuration. Glucuronic acid conjugates are a common type of metabolites formed by the human body. The detection of such conjugates in doping control and other kinds of forensic analysis would be beneficial owing to a decrease in analysis time as hydrolysis can be omitted. However the commercial availability of reference standards for drug glucuronides is poor. The selective androgen receptor modulator (SARM) SARM S1 was incubated with the fungus C. elegans. The sample was treated with the free radical TEMPO oxidizing agent and was thereafter purified by SPE. A glucuronic acid conjugate was isolated using a fraction collector connected to an ultra high performance liquid chromatographic (UHPLC) system. The isolated compound was characterized by NMR spectroscopy and mass spectrometry and its structure was confirmed as a glucuronic acid β-conjugate of hydroxylated SARM S1 bearing the glucuronide moiety on carbon C-10. PMID:24879518

  8. Isolated Fungal Promoters and Gene Transcription Terminators and Methods of Protein and Chemical Production in a Fungus

    DOEpatents

    Dai, Ziyu; Lasure, Linda L.; Magnuson, Jon K.

    2008-11-11

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  9. Isolated fungal promoters and gene transcription terminators and methods of protein and chemical production in a fungus

    DOEpatents

    Dai, Ziyu; Lasure, Linda L; Magnuson, Jon K

    2014-05-27

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  10. Isolated fungal promoters and gene transcription terminators and methods of protein and chemical production in a fungus

    DOEpatents

    Dai, Ziyu; Lasure, Linda L.; Magnuson, Jon K.

    2008-11-11

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  11. Ultrastructural analysis of the behavior of the dimorphic fungus Microbotryum violaceum in fungus-induced anthers of female Silene latifolia flowers.

    PubMed

    Uchida, Wakana; Matsunaga, Sachihiro; Kawano, Shigeyuki

    2005-12-01

    The development of male organs is induced in female flowers of the dioecious plant Silene latifolia by infection with the fungus Microbotryum violaceum. Stamens in a healthy female flower grow only to stage 6, whereas those in an infected female flower develop to the mature stage (stage 12), at which the stamens are filled with fungal teliospores instead of pollen grains. To investigate these host-parasite interactions, young floral buds and fungus-induced anthers of infected female flowers were examined by electron microscopy following fixation by a high-pressure freezing method. Using this approach, we found that parasitic hyphae of this fungus contain several extracellular vesicles and have a consistent appearance up to stage 8. At that stage, parasitic hyphae are observed adjacent to dying sporogenous cells in the infected female anther. At stage 9, an increased number of dead and dying sporogenous cells is observed, among which the sporogenous hyphae of the fungus develop and form initial teliospores. Several types of electron-dense material are present in proximity to some fungi at this stage. The initial teliospores contain two types of vacuoles, and the fungus cell wall contains abundant carbohydrate, as revealed by silver protein staining. The sporogenous cell is probably sensitive to infection by the fungus, resulting in disruption. In addition, the fungus accelerates cell death in the anther and utilizes constituents of the dead host cell to form the mature teliospore. PMID:16333578

  12. The nematode Caenorhabditis elegans as an integrated toxicological tool to assess water quality and pollution.

    PubMed

    Clavijo, Araceli; Kronberg, María Florencia; Rossen, Ariana; Moya, Aldana; Calvo, Daniel; Salatino, Santa Esmeralda; Pagano, Eduardo Antonio; Morábito, José Antonio; Munarriz, Eliana Rosa

    2016-11-01

    Determination of water quality status in rivers is critical to establish a sustainable water management policy. For this reason, over the last decades it has been recommended to perform integrated water assessments that include water quantities and physicochemical, ecological and toxicological tests. However, sometimes resources are limited and it is not possible to perform large-scale chemical determinations of pollutants or conduct numerous ecotoxicological tests. To overcome this problem we use and measure the growth, as a response parameter, of the soil nematode Caenorhabditis elegans to assess water quality in rivers. The C. elegans is a ubiquitous organism that has emerged as an important model organism in aquatic and soil toxicology research. The Tunuyán River Basin (Province of Mendoza, Argentina) has been selected as a representative traditional water monitoring system to test the applicability of the C. elegans toxicological bioassay to generate an integrated water quality evaluation. Jointly with the C. elegans toxic assays, physicochemical and bacteriological parameters were determined for each monitoring site. C. elegans bioassays help to identify different water qualities in the river basin. Multivariate statistical analysis (PCA and linear regression models) has allowed us to confirm that traditional water quality studies do not predict potential toxic effects on living organisms. On the contrary, physicochemical and bacteriological analyzes explain <62% of the C. elegans growth response variability, showing that ecotoxicological bioassays are important to obtain a realistic scenario of water quality threats. Our results confirm that the C. elegans bioassay is a sensible and suitable tool to assess toxicity and should be implemented in routine water quality monitoring. PMID:27343944

  13. Carbohydrate Storage in the Entomopathogenic Fungus Beauveria bassiana

    PubMed Central

    Bidochka, Michael J.; Low, Nicholas H.; Khachatourians, George G.

    1990-01-01

    The entomopathogenic fungus Beauveria bassiana was grown in 1% (wt/vol) gelatin-liquid media singly supplemented with a monosaccharide (glucose or fructose), a disaccharide (maltose or trehalose), a polyol (glycerol, mannitol, or sorbitol), or the amino sugar N-acetyl-d-glucosamine. The relative contributions of the carbohydrate, protein, and water contents in the fungal biomass were determined. Carbohydrates composed 18 to 42% of the mycelial dry weight, and this value was lowest in unsupplemented medium and highest in medium supplemented with glucose, glycerol, or trehalose. Biomass production was highest in liquid cultures supplemented with trehalose. When liquid cultures were grown in medium supplemented with 0 to 1% (wt/vol) glucose, trehalose, or N-acetyl-d-glucosamine, there was an increase in the biomass production and the contribution of carbohydrate to mycelial dry weight. Regardless of the glucose concentration in the culture, water content of the mycelia remained about 77.5% (wt/wt). Mycelial storage carbohydrates were determined by capillary gas chromatography. In gelatin-liquid medium supplemented with 1% (wt/vol) glucose, B. bassiana stored glycogen (12.0%, wt/dry wt) and the polyols mannitol (2.2%), erythritol (1.6%), glycerol (0.4%), and arabitol (0.1%). Without glucose, B. bassiana stored glycogen (5.4%), mannitol (0.8%), glycerol (0.6%), and erythritol (0.6%) but not arabitol. To our knowledge, this is the first report of carbohydrate storage in an entomopathogenic fungus, and the results are discussed in relation to other fungi and the potential implications to commercial formulation and insect-fungus interactions. PMID:16348325

  14. Angiotensin Converting Enzyme (ACE) Inhibitor Extends Caenorhabditis elegans Life Span.

    PubMed

    Kumar, Sandeep; Dietrich, Nicholas; Kornfeld, Kerry

    2016-02-01

    Animal aging is characterized by progressive, degenerative changes in many organ systems. Because age-related degeneration is a major contributor to disability and death in humans, treatments that delay age-related degeneration are desirable. However, no drugs that delay normal human aging are currently available. To identify drugs that delay age-related degeneration, we used the powerful Caenorhabditis elegans model system to screen for FDA-approved drugs that can extend the adult lifespan of worms. Here we show that captopril extended mean lifespan. Captopril is an angiotensin-converting enzyme (ACE) inhibitor used to treat high blood pressure in humans. To explore the mechanism of captopril, we analyzed the acn-1 gene that encodes the C. elegans homolog of ACE. Reducing the activity of acn-1 extended the mean life span. Furthermore, reducing the activity of acn-1 delayed age-related degenerative changes and increased stress resistance, indicating that acn-1 influences aging. Captopril could not further extend the lifespan of animals with reduced acn-1, suggesting they function in the same pathway; we propose that captopril inhibits acn-1 to extend lifespan. To define the relationship with previously characterized longevity pathways, we analyzed mutant animals. The lifespan extension caused by reducing the activity of acn-1 was additive with caloric restriction and mitochondrial insufficiency, and did not require sir-2.1, hsf-1 or rict-1, suggesting that acn-1 functions by a distinct mechanism. The interactions with the insulin/IGF-1 pathway were complex, since the lifespan extensions caused by captopril and reducing acn-1 activity were additive with daf-2 and age-1 but required daf-16. Captopril treatment and reducing acn-1 activity caused similar effects in a wide range of genetic backgrounds, consistent with the model that they act by the same mechanism. These results identify a new drug and a new gene that can extend the lifespan of worms and suggest new

  15. Angiotensin Converting Enzyme (ACE) Inhibitor Extends Caenorhabditis elegans Life Span

    PubMed Central

    Kumar, Sandeep; Dietrich, Nicholas; Kornfeld, Kerry

    2016-01-01

    Animal aging is characterized by progressive, degenerative changes in many organ systems. Because age-related degeneration is a major contributor to disability and death in humans, treatments that delay age-related degeneration are desirable. However, no drugs that delay normal human aging are currently available. To identify drugs that delay age-related degeneration, we used the powerful Caenorhabdtitis elegans model system to screen for FDA-approved drugs that can extend the adult lifespan of worms. Here we show that captopril extended mean lifespan. Captopril is an angiotensin-converting enzyme (ACE) inhibitor used to treat high blood pressure in humans. To explore the mechanism of captopril, we analyzed the acn-1 gene that encodes the C. elegans homolog of ACE. Reducing the activity of acn-1 extended the mean life span. Furthermore, reducing the activity of acn-1 delayed age-related degenerative changes and increased stress resistance, indicating that acn-1 influences aging. Captopril could not further extend the lifespan of animals with reduced acn-1, suggesting they function in the same pathway; we propose that captopril inhibits acn-1 to extend lifespan. To define the relationship with previously characterized longevity pathways, we analyzed mutant animals. The lifespan extension caused by reducing the activity of acn-1 was additive with caloric restriction and mitochondrial insufficiency, and did not require sir-2.1, hsf-1 or rict-1, suggesting that acn-1 functions by a distinct mechanism. The interactions with the insulin/IGF-1 pathway were complex, since the lifespan extensions caused by captopril and reducing acn-1 activity were additive with daf-2 and age-1 but required daf-16. Captopril treatment and reducing acn-1 activity caused similar effects in a wide range of genetic backgrounds, consistent with the model that they act by the same mechanism. These results identify a new drug and a new gene that can extend the lifespan of worms and suggest new

  16. Identification of a gonadotropin-releasing hormone receptor orthologue in Caenorhabditis elegans

    PubMed Central

    Vadakkadath Meethal, Sivan; Gallego, Miguel J; Haasl, Ryan J; Petras, Stephen J; Sgro, Jean-Yves; Atwood, Craig S

    2006-01-01

    Background The Caenorhabditis elegans genome is known to code for at least 1149 G protein-coupled receptors (GPCRs), but the GPCR(s) critical to the regulation of reproduction in this nematode are not yet known. This study examined whether GPCRs orthologous to human gonadotropin-releasing hormone receptor (GnRHR) exist in C. elegans. Results Our sequence analyses indicated the presence of two proteins in C. elegans, one of 401 amino acids [GenBank: NP_491453; WormBase: F54D7.3] and another of 379 amino acids [GenBank: NP_506566; WormBase: C15H11.2] with 46.9% and 44.7% nucleotide similarity to human GnRHR1 and GnRHR2, respectively. Like human GnRHR1, structural analysis of the C. elegans GnRHR1 orthologue (Ce-GnRHR) predicted a rhodopsin family member with 7 transmembrane domains, G protein coupling sites and phosphorylation sites for protein kinase C. Of the functionally important amino acids in human GnRHR1, 56% were conserved in the C. elegans orthologue. Ce-GnRHR was actively transcribed in adult worms and immunoanalyses using antibodies generated against both human and C. elegans GnRHR indicated the presence of a 46-kDa protein, the calculated molecular mass of the immature Ce-GnRHR. Ce-GnRHR staining was specifically localized to the germline, intestine and pharynx. In the germline and intestine, Ce-GnRHR was localized specifically to nuclei as revealed by colocalization with a DNA nuclear stain. However in the pharynx, Ce-GnRHR was localized to the myofilament lattice of the pharyngeal musculature, suggesting a functional role for Ce-GnRHR signaling in the coupling of food intake with reproduction. Phylogenetic analyses support an early evolutionary origin of GnRH-like receptors, as evidenced by the hypothesized grouping of Ce-GnRHR, vertebrate GnRHRs, a molluscan GnRHR, and the adipokinetic hormone receptors (AKHRs) and corazonin receptors of arthropods. Conclusion This is the first report of a GnRHR orthologue in C. elegans, which shares significant

  17. Study about locomotory ability of dystrophin-defected C.elegans after spaceflight

    NASA Astrophysics Data System (ADS)

    Gao, Ying; Sun, Yeqing; Lei, Huang; Xu, Dan

    2012-07-01

    Space microgravity could induce a variety of biological changes such as muscular atrophy. Recent studies show that gravisensing is a key point in muscular atrophy process, but the molecular mechanism is still unknown. Dystrophin, a muscle-related protein, plays an important role in muscle development. It is reported that mutation of human dystrophin gene could cause muscular atrophy. In this study, we focus on whether dystrophin gene acts as a gravisensing factor and observe locomotory ability of dystrophin-defected Caenorhabditis elegans (C.elegans) after spaceflight. We used wild-type (WT) and dystrophin-defected (dys-1) mutant of C.elegans, which were cultured to dauer stage and sent to space by Shenzhou 8 spacecraft (from Nov 1st to 17th, 2011). These worms were divided into three groups: space group (space radiation and microgravity conditions), space control group (space radiation and chmetcnvTCSC0NumberType1NegativeFalseHasSpaceFalseSourceValue1UnitNameg1g centrifuge force conditions) and ground control group.We already observed the progeny (generation F1 and F2) of worms which were sent to space, the movement of C. elegans is restricted to a two-dimensional sinusoidal pattern, and evaluated locomotory ability by the ratio (length/width) in crawl trace wave of C. elegans. The increased value of ratio indicates the decrease in locomotory ability of C. elegans. Our results from generation F1 showed that WT worms in space group(7.7±1.8) demonstrated the significant decrease in locomotory ability about 15%, compared with those in space control group(6.7±1.2). This finding indicates that locomotory ability of C. elegans progeny could be affected by microgravity in space environment. In comparison to the obvious difference in ratio between space group and space control group for WT worms, there is no significant difference between two space groups of generation F2 .For dys-1 mutant of C.elegans (generation F1 and F2), the results show that dystrophin deficiency

  18. Cytotoxic cytochalasins from marine-derived fungus Arthrinium arundinis.

    PubMed

    Wang, Junfeng; Wang, Zhen; Ju, Zhiran; Wan, Junting; Liao, Shengrong; Lin, Xiuping; Zhang, Tianyu; Zhou, Xuefeng; Chen, Hao; Tu, Zhengchao; Liu, Yonghong

    2015-01-01

    Four new cytochalasins, arthriniumnins A-D (1-4), a new natural product, ketocytochalasin (5), as well as five known cytochalasin analogues (6-10) were isolated and identified from the fungus Arthrinium arundinis ZSDS1-F3 from the sponge Phakellia fusca. Their structures were elucidated by NMR spectroscopic and mass spectrometric analyses, as well as single crystal X-ray diffraction. Compounds 6 and 9 showed cytotoxicity against K562, A549, Huh-7, H1975, MCF-7, U937, BGC823, HL60, Hela, and MOLT-4 cell lines, with IC50 values ranging from 1.13 to 47.4 µM. PMID:25626143

  19. Two new antimicrobial metabolites from the endophytic fungus, Seimatosporium sp.

    PubMed

    Hussain, Hidayat; Krohn, Karsten; Schulz, Barbara; Draeger, Siegfried; Nazir, Mamona; Saleem, Muhammad

    2012-03-01

    Two new acaranoic acids, named seimatoporic acid A and B (1, and 2), together with six known compounds, R-(-)-mellein (3), cis-4-hydroxymellein (4), trans-4-hydroxymellein (5), 4R-hydroxy-5-methylmellein (6), (-)-5-hydroxymethylmellein (7), and ergosterol (8) were isolated from an endophytic fungus, Seimatosporium sp, by a bioassay-guided procedure. The structures of the new compounds have been assigned from analysis of the 1H and 13C NMR spectra, DEPT, and by 2D COSY, HMQC, HMBC and NOESY experiments. A mixture of compounds 1 and 2 showed strong antifungal activity against Botrytis cinerea, Septoria tritici, and Pyricularia oryzae. PMID:22545398

  20. Polyoxygenated methyl cyclohexanoids from a terrestrial ampelomyces fungus.

    PubMed

    Zhang, Huiye; Xue, Jinghua; Wu, Ping; Xu, Liangxiong; Xie, Haihui; Wei, Xiaoyi

    2009-02-27

    Seven structurally related new polyoxygenated methyl cyclohexanoids, ampelomins A-G (1-7), were isolated from the mycelial solid culture of a soil-derived Ampelomyces fungus. Their structures were determined by spectroscopic and chemical means. Ampelomins A (1), C (3), E (5), and G (7) exhibited weak activity against alpha-glucosidase with IC(50) values of 1.74-5.93 mM, and ampelomin A (1) showed moderate antibacterial activity with MIC(90) values ranging from 202.4 to 1015.9 microM. A plausible polyketide biogenetic pathway is postulated for these compounds. PMID:19193024