Sample records for blastochloris viridis heterodimer

  1. Structural and spectropotentiometric analysis of Blastochloris viridis heterodimer mutant reaction center

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    Ponomarenko, Nina S.; Li, Liang; Marino, Antony R.; Tereshko, Valentina; Ostafin, Agnes; Popova, Julia A.; Bylina, Edward J.; Ismagilov, Rustem F.; Norris, Jr., James R.; (UC); (Utah)


    Heterodimer mutant reaction centers (RCs) of Blastochloris viridis were crystallized using microfluidic technology. In this mutant, a leucine residue replaced the histidine residue which had acted as a fifth ligand to the bacteriochlorophyll (BChl) of the primary electron donor dimer M site (HisM200). With the loss of the histidine-coordinated Mg, one bacteriochlorophyll of the special pair was converted into a bacteriopheophytin (BPhe), and the primary donor became a heterodimer supermolecule. The crystals had dimensions 400 x 100 x 100 {micro}m, belonged to space group P4{sub 3}2{sub 1}2, and were isomorphous to the ones reported earlier for the wild type (WT) strain. The structure was solved to a 2.5 {angstrom} resolution limit. Electron-density maps confirmed the replacement of the histidine residue and the absence of Mg. Structural changes in the heterodimer mutant RC relative to the WT included the absence of the water molecule that is typically positioned between the M side of the primary donor and the accessory BChl, a slight shift in the position of amino acids surrounding the site of the mutation, and the rotation of the M194 phenylalanine. The cytochrome subunit was anchored similarly as in the WT and had no detectable changes in its overall position. The highly conserved tyrosine L162, located between the primary donor and the highest potential heme C{sub 380}, revealed only a minor deviation of its hydroxyl group. Concomitantly to modification of the BChl molecule, the redox potential of the heterodimer primary donor increased relative to that of the WT organism (772 mV vs. 517 mV). The availability of this heterodimer mutant and its crystal structure provides opportunities for investigating changes in light-induced electron transfer that reflect differences in redox cascades.

  2. Photosynthetic system in Blastochloris viridis revisited. (United States)

    Konorty, Marina; Brumfeld, Vlad; Vermeglio, Andre; Kahana, Nava; Medalia, Ohad; Minsky, Abraham


    The bacterium Blastochloris viridis carries one of the simplest photosynthetic systems, which includes a single light-harvesting complex that surrounds the reaction center, membrane soluble quinones, and a soluble periplasmic protein cytochrome c(2) that shuttle between the reaction center and the bc(1) complex and act as electron carriers, as well as the ATP synthase. The close arrangement of the photosynthetic membranes in Bl. viridis, along with the extremely tight arrangement of the photosystems within these membranes, raises a fundamental question about the diffusion of the electron carriers. To address this issue, we analyzed the structure and response of the Bl. viridis photosynthetic system to various light conditions, by using a combination of electron microscopy, whole-cell cryotomography, and spectroscopic methods. We demonstrate that in response to high light intensities, the ratio of both cytochrome c(2) and bc(1) complexes to the reaction centers is increased. The shorter membrane stacks, along with the notion that the bc(1) complex is located at the highly curved edges of these stacks, result in a smaller average distance between the reaction centers and the bc(1) complexes, leading to shorter pathways of cytochrome c(2) between the two complexes. Under anaerobic conditions, the slow diffusion rate is further mitigated by keeping most of the quinone pool reduced, resulting in a concentration gradient of quinols that allows for a constant supply of theses electron carriers to the bc(1) complex.

  3. New insights into the structure of the reaction centre from Blastochloris viridis: evolution in the laboratory. (United States)

    Roszak, Aleksander W; Moulisová, Vladimíra; Reksodipuro, Adhie D P; Gardiner, Alastair T; Fujii, Ritsuko; Hashimoto, Hideki; Isaacs, Neil W; Cogdell, Richard J


    Newly determined crystal structures of the photosynthetic RC (reaction centre) from two substrains of the non-sulfur purple bacterium Blastochloris viridis strain DSM 133, together with analysis of their gene sequences, has revealed intraspecies evolutionary changes over a period of 14 years. Over 100 point mutations were identified between these two substrains in the four genes encoding the protein subunits of the RC, of which approximately one-fifth resulted in a total of 16 amino acid changes. The most interesting difference was in the M subunit where the change from a leucine residue to glycine in the carotenoid-binding pocket allowed NS5 (1,2-dihydroneurosporene) to adopt a more sterically favoured conformation, similar to the carotenoid conformation found in other related RCs. The results of the present study, together with a high rate of mutations in laboratory bacterial cultures described recently, suggest that bacteria evolve faster than has been generally recognized. The possibility that amino acid changes occur within protein sequences, without exhibiting any immediately observable phenotype, should be taken into account in studies that involve long-term continuous growth of pure bacterial cultures. The Blc. viridis RC is often studied with sophisticated biophysical techniques and changes such as those described here may well affect their outcome. In other words, there is a danger that laboratory-to-laboratory variation could well be due to different groups not realising that they are actually working with slightly different proteins. A way around this problem is suggested.

  4. Chemosensory response in stunted prairie rattlesnakes Crotalus viridis viridis

    Institute of Scientific and Technical Information of China (English)

    Anthony J.SAVIOLA; David CHISZAR; Hobart M.SMITH; Stephen P.MACKESSY


    Rattlesnakes use chemical stimuli in ambush site selection and for relocation of envenomated prey through strike-induced chemosensory searching.Shifts in responsiveness to prey chemicals have been documented in many snakes,and often correlate with prey commonly taken as snakes increase in age and size as well as geographical locations of the species.For instance,neonate rattlesnakes that prey primarily on ectotherms responded most strongly to chemical cues of commonly taken lizard prey,whereas adult rattlesnakes that prey primarily on small mammals responded significantly to chemical cues of commonly taken rodents.In the current study,11 Prairie Rattlesnakes Crotalus viridis viridis which were classified as large neonates based on measures of snout-vent length (SVL) and body mass,yet chronologically were at or near adulthood,were tested for their responsiveness to chemical extracts of natural and non-natural prey items.Although the snakes had eaten only neonate lab mice (Mus musculus),they responded significantly more to chemical cues of natural prey items and particularly to chemical cues of prey normally taken by subadults (Peromyscus mice and Sceloporus lizard).These results suggest that ontogenetic shifts in responsiveness to natural prey chemical cues are innately programmed and are not based on body size or feeding experience in C.v.viridis.This does not imply,however,that growth and experience are without effects,especially with novel prey or rare prey that have experienced recent population expansion.

  5. Secondary peritonitis caused by Streptomyces viridis

    NARCIS (Netherlands)

    P. Datta (Priya); S. Arora (Shilpa); A. Jain (Ashok); J. Chander (Jagdish); W.W.J. van de Sande (Wendy)


    textabstractStreptomyces organisms are soil inhabitants rarely causing nonmycetomic infections. We describe a case of secondary peritonitis caused by Streptomyces viridis in a chronic alcoholic patient who presented with fever, abdominal distension, and pain in the abdomen. The most likely source of

  6. Short Note. Chemosensory response in stunted prairie rattle snakes Crotalus viridis viridis

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    Anthony J. SAVIOLA, David CHISZAR, Hobart M. SMITH,Stephen P. MACKESSY


    Full Text Available Rattlesnakes use chemical stimuli in ambush site selection and for relocation of envenomated prey through strike-induced chemosensory searching. Shifts in responsiveness to prey chemicals have been documented in many snakes, and often correlate with prey commonly taken as snakes increase in age and size as well as geographical locations of the species. For instance, neonate rattlesnakes that prey primarily on ectotherms responded most strongly to chemical cues of commonly taken lizard prey, whereas adult rattlesnakes that prey primarily on small mammals responded significantly to chemical cues of commonly taken rodents. In the current study, 11 Prairie Rattlesnakes Crotalus viridis viridis which were classified as large neonates based on measures of snout-vent length (SVL and body mass, yet chronologically were at or near adulthood, were tested for their responsiveness to chemical extracts of natural and non-natural prey items. Although the snakes had eaten only neonate lab mice (Mus musculus, they responded significantly more to chemical cues of natural prey items and particularly to chemical cues of prey normally taken by subadults (Peromyscus mice and Sceloporus lizard. These results suggest that ontogenetic shifts in responsiveness to natural prey chemical cues are innately programmed and are not based on body size or feeding experience in C. v. viridis. This does not imply, however, that growth and experience are without effects, especially with novel prey or rare prey that have experienced recent population expansion [Current Zoology 59 (2: 175-179, 2013].

  7. The formation of heterodimers by vancomycin group antibiotics

    DEFF Research Database (Denmark)

    Staroske, T; O'Brien, DP; Jørgensen, Thomas J. D.;


    The formation of heterodimers in mixtures of glycopeptide antibiotics has been detected by electrospray ionization mass spectrometry (ESI-MS), and dimerization constants have been determined. By using NMR spectroscopy, it has been shown that these heterodimers indeed exist in aqueous solution. Th...

  8. Ontogenetic shift in response to prey-derived chemical cues in prairie rattlesnakes Crotalus viridis viridis

    Institute of Scientific and Technical Information of China (English)

    Anthony J.SAVIOLA; David CHISZAR; Stephen P.MACKESSY


    Snakes often have specialized diets that undergo a shift from one prey type to another depending on the life stage of the snake.Crotalus viridis viridis (prairie rattlesnake) takes different prey at different life stages,and neonates typically prey on ectotherms,while adults feed almost entirely on small endotherms.We hypothesized that elevated rates of tongue flicking to chemical stimuli should correlate with particular prey consumed,and that this response shifts from one prey type to another as individuals age.To examine if an ontogenetic shift in response to chemical cues occurred,we recorded the rate of tongue flicking for 25 neonate,20 subadult,and 20 adult (average SVL=280.9,552,789.5 mm,respectively) wild-caught C.v.viridis to chemical stimuli presented on a cotton-tipped applicator; water-soluble cues from two ectotherms (prairie lizard,Sceloporus undulatus,and house gecko,Hemidactylusfrenatus),two endotherms (deer mouse,Peromyscus maniculatus and lab mouse,Mus musculus),and water controls were used.Neonates tongue flicked significantly more to chemical cues of their common prey,S.undulatus,than to all other chemical cues; however,the response to this lizard's chemical cues decreased in adult rattlesnakes.Subadults tongue flicked with a higher rate of tongue flicking to both S.undulatus and P.maniculatus than to all other treatments,and adults tongue flicked significantly more to P.maniculatus than to all other chemical cues.In addition,all three sub-classes demonstrated a greater response for natural prey chemical cues over chemical stimuli of prey not encountered in the wild (M.musculus and H.frenatus).This shift in chemosensory response correlated with the previously described ontogenetic shifts in C.v.viridis diet.Because many vipers show a similar ontogenetic shift in diet and venom composition,we suggest that this shift in prey cue discrimination is likely a general phenomenon among viperid snakes.

  9. Methods to promote germination of dormant Setaria viridis seeds. (United States)

    Sebastian, Jose; Wong, Mandy Ka; Tang, Evan; Dinneny, José R


    Setaria viridis has recently emerged as a promising genetic model system to study diverse aspects of monocot biology. While the post-germination life cycle of S. viridis is approximately 8 weeks long, the prolonged dormancy of freshly harvested seeds can more than double the total time required between successive generations. Here we describe methods that promote seed germination in S. viridis. Our results demonstrate that treating S. viridis seeds with liquid smoke or a GA3 and KNO3 solution improves germination rates to 90% or higher even in seeds that are 6 days post-harvest with similar results obtained whether seeds are planted in soil or on gel-based media. Importantly, we show that these treatments have no significant effect on the growth of the adult plant. We have tested these treatments on diverse S. viridis accessions and show variation in their response. The methods described here will help advance research using this model grass species by increasing the pace at which successive generations of plants can be analyzed.

  10. Methods to promote germination of dormant Setaria viridis seeds.

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    Jose Sebastian

    Full Text Available Setaria viridis has recently emerged as a promising genetic model system to study diverse aspects of monocot biology. While the post-germination life cycle of S. viridis is approximately 8 weeks long, the prolonged dormancy of freshly harvested seeds can more than double the total time required between successive generations. Here we describe methods that promote seed germination in S. viridis. Our results demonstrate that treating S. viridis seeds with liquid smoke or a GA3 and KNO3 solution improves germination rates to 90% or higher even in seeds that are 6 days post-harvest with similar results obtained whether seeds are planted in soil or on gel-based media. Importantly, we show that these treatments have no significant effect on the growth of the adult plant. We have tested these treatments on diverse S. viridis accessions and show variation in their response. The methods described here will help advance research using this model grass species by increasing the pace at which successive generations of plants can be analyzed.

  11. Intoxication of sheep exposed to ozark milkweed (Asclepias viridis Walter). (United States)

    Smith, R A; Scharko, P; Bolin, D; Hong, C B


    Some 20 sheep died 1 at a time on a farm in Fleming County, KY, in late July of 1999 after consumption of Asclepias viridis Walter. Major histological lesions were mild multifocal nonsuppurative myocarditis. Gross pathology revealed wet and heavy lungs. Many affected animals had a hunched appearance, and marked posterior paresis was also observed.

  12. Resonance Coupling in Plasmonic Nanomatryoshka Homo- and Heterodimers (United States)


    bonding modes excited due to the energy coupling between silver and gold NM units in a heterodimer structure. Our analysis suggest abnormal shifts in...sensing,2 and surface- enhanced Raman spectroscopy (SERS).3 Studies have strongly proved that various parameters such as shape, geomet- rical dimensions...proximity to each other are recog- nized as a two-member dimer configuration, which provides a significant EM field enhancement and localization of plasmon

  13. Resonance coupling in plasmonic nanomatryoshka homo- and heterodimers (United States)

    Ahmadivand, Arash; Sinha, Raju; Pala, Nezih


    Here, we examine the electromagnetic (EM) energy coupling and hybridization of plasmon resonances between closely spaced concentric nanoshells known as "nanomatryoshka" (NM) units in symmetric and antisymmetric compositions using the Finite Difference Time Domain (FDTD) analysis. Utilizing plasmon hybridization model, we calculated the energy level diagrams and verified that, in the symmetric dimer (in-phase mode in a homodimer), plasmonic bonding modes are dominant and tunable within the considered bandwidth. In contrast, in the antisymmetric dimer (out-of-phase mode in a heterodimer), due to the lack of the geometrical symmetry, new antibonding modes appear in the extinction profile, and this condition gives rise to repeal of dipolar field coupling. We also studied the extinction spectra and positions of the antibonding and bonding modes excited due to the energy coupling between silver and gold NM units in a heterodimer structure. Our analysis suggest abnormal shifts in the higher energy modes. We propose a method to analyze the behavior of multilayer concentric nanoshell particles in an antisymmetric orientation employing full dielectric function calculations and the Drude model based on interband transitions in metallic components. This study provides a method to predict the behavior of the higher energy plasmon resonant modes in entirely antisymmetric structures such as compositional heterodimers.

  14. Resonance coupling in plasmonic nanomatryoshka homo- and heterodimers

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    Arash Ahmadivand


    Full Text Available Here, we examine the electromagnetic (EM energy coupling and hybridization of plasmon resonances between closely spaced concentric nanoshells known as “nanomatryoshka” (NM units in symmetric and antisymmetric compositions using the Finite Difference Time Domain (FDTD analysis. Utilizing plasmon hybridization model, we calculated the energy level diagrams and verified that, in the symmetric dimer (in-phase mode in a homodimer, plasmonic bonding modes are dominant and tunable within the considered bandwidth. In contrast, in the antisymmetric dimer (out-of-phase mode in a heterodimer, due to the lack of the geometrical symmetry, new antibonding modes appear in the extinction profile, and this condition gives rise to repeal of dipolar field coupling. We also studied the extinction spectra and positions of the antibonding and bonding modes excited due to the energy coupling between silver and gold NM units in a heterodimer structure. Our analysis suggest abnormal shifts in the higher energy modes. We propose a method to analyze the behavior of multilayer concentric nanoshell particles in an antisymmetric orientation employing full dielectric function calculations and the Drude model based on interband transitions in metallic components. This study provides a method to predict the behavior of the higher energy plasmon resonant modes in entirely antisymmetric structures such as compositional heterodimers.

  15. Amino acid sequence and disulfide bond assignment of myotoxin a isolated from the venom of prairie rattlesnake (Crotalus viridis viridis)

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.W.; Elzinga, M.; Tu, A.T.


    The primary structure of myotoxin a, a myotoxin protein from the venom of the North American rattlesnake Crotalus viridis viridis, was determined and the position of the disulfide bonds assigned. The toxin was isolated, carboxymethylated, and cleaved by cyanogen bromide, and the resultant peptides were isolated. The cyanogen bromide peptides were subjected to amino acid sequence analysis. In order to assign the positions of the three disulfide bonds, the native toxin was cleaved sequentially with cyanogen bromide and trypsin. A two peptide unit connected by one disulfide bond was isolated and characterized, and a three-peptide unit connected by two disulfide bonds was isolated. One peptide in the three-peptide unit was identified as Cys-Cys-Lys. In order to establish the linkages between the peptides and Cys-Cys-Lys, one cycle of Edman degradation was carried out such that the Cys-Cys bond was cleaved. Upon isolation and analysis of the cleavage products, the disulfide bonds connecting the three peptides were determined. The positions of the disulfide bridges of myotoxin a were determined to be totally different from those of neurotoxins isolated from snake venoms. The sequence of myotoxin a was compared with the sequences of other snake venom toxins using the computer program RELATE to determine whether myotoxin a is similar to any other types of toxins. From the computer analysis, myotoxin a did not show any close relationship to other toxins except crotamine from the South American rattlesnake Crotalus durissus terrificus.

  16. RNA recognition by the DNA end-binding Ku heterodimer. (United States)

    Dalby, Andrew B; Goodrich, Karen J; Pfingsten, Jennifer S; Cech, Thomas R


    Most nucleic acid-binding proteins selectively bind either DNA or RNA, but not both nucleic acids. The Saccharomyces cerevisiae Ku heterodimer is unusual in that it has two very different biologically relevant binding modes: (1) Ku is a sequence-nonspecific double-stranded DNA end-binding protein with prominent roles in nonhomologous end-joining and telomeric capping, and (2) Ku associates with a specific stem-loop of TLC1, the RNA subunit of budding yeast telomerase, and is necessary for proper nuclear localization of this ribonucleoprotein enzyme. TLC1 RNA-binding and dsDNA-binding are mutually exclusive, so they may be mediated by the same site on Ku. Although dsDNA binding by Ku is well studied, much less is known about what features of an RNA hairpin enable specific recognition by Ku. To address this question, we localized the Ku-binding site of the TLC1 hairpin with single-nucleotide resolution using phosphorothioate footprinting, used chemical modification to identify an unpredicted motif within the hairpin secondary structure, and carried out mutagenesis of the stem-loop to ascertain the critical elements within the RNA that permit Ku binding. Finally, we provide evidence that the Ku-binding site is present in additional budding yeast telomerase RNAs and discuss the possibility that RNA binding is a conserved function of the Ku heterodimer.

  17. SdAb heterodimer formation using leucine zippers (United States)

    Goldman, Ellen R.; Anderson, George P.; Brozozog-Lee, P. Audrey; Zabetakis, Dan


    Single domain antibodies (sdAb) are variable domains cloned from camel, llama, or shark heavy chain only antibodies, and are among the smallest known naturally derived antigen binding fragments. SdAb derived from immunized llamas are able to bind antigens with high affinity, and most are capable of refolding after heat or chemical denaturation to bind antigen again. We hypothesized that the ability to produce heterodimeric sdAb would enable reagents with the robust characteristics of component sdAb, but with dramatically improved overall affinity through increased avidity. Previously we had constructed multimeric sdAb by genetically linking sdAb that bind non-overlapping epitopes on the toxin, ricin. In this work we explored a more flexible approach; the construction of multivalent binding reagents using multimerization domains. We expressed anti-ricin sdAb that recognize different epitopes on the toxin as fusions with differently charged leucine zippers. When the initially produced homodimers are mixed the leucine zipper domains will pair to produce heterodimers. We used fluorescence resonance energy transfer to confirm heterodimer formation. Surface plasmon resonance, circular dichroism, enzyme linked immunosorbent assays, and fluid array assays were used to characterize the multimer constructs, and evaluate their utility in toxin detection.

  18. Antifouling activity of Indian marine invertebrate against the green mussel Perna viridis L.

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Jayasree, V.; Naik, C.G.; Parameswaran, P.S.; Raveendran, T.V.; Kamat, S.Y.

    viridis L. The repulsive action of the foot and production of byssus threads by green mussels were used for assaying the above activity. Subergorgia suberosa, Sinularia numerosa, Sinularia compressa, Cladiella pachyclados (phylum Coelenterata), Haliclona...

  19. Comparative Studies on Uptake Pathway of Cadmium by Perna viridis

    Institute of Scientific and Technical Information of China (English)


    Experiments were designed to expose the filter-feeding bivalve Perna viridis to different Cd-contaminated water environments in order to compare the different pathways through which Cd is accumulated. Results show that mussels can accumulate Cd through seawater, food, sediment and suspended particle pathways in a short period of time. Mussels uptake of Cd through the seawater pathway reaches the highest concentration approximately 3 and 9 times larger than through the algae and sediment pathways respectively after 7 d. This indicates that the Cd-accumulation through seawater is most efficient. Results also indicate that the uptake directly through contaminated algae, particles or sediments ingested by mussels is less important when compared with the uptake of Cd by mussels through the seawater pathway. Metal uptake pathways and mechanisms of bioaccumulation by marine bivalve are also discussed in this paper.

  20. Excretory Products of Green Mussel Perna viridis L. and their Implications on Power Plant Operation


    Masilamoni, J. Gunasingh; AZARIAH, J.; Nandakumar, K.


    Excretion in marine animals is considered an important factor in assessing physiological status. Perna viridis, a widely distributed bivalve species, was found to be the dominant (>70%) organism in the seawater intake tunnel of Madras Atomic Power Station (MAPS). The excretion patterns (ammonia, nitrite, phosphate and fecal matter production) of three different size groups (4-5 cm, 6-7 cm, and 8-9 cm shell length) of P. viridis were studied in the laboratory at different salinities (15, 20...

  1. Remarks on the Echiniscus viridis group, with the description of a new species (Tardigrada, Echiniscidae

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    Oscar LISI


    Full Text Available A new species, Echiniscus viridianus sp. n., is described in the Echiniscus viridis group from North America and the Azores Islands. It clearly differs from E. viridis in some details of the cuticular ornamentation (it has dark tubercles quite close to each other and larger light spots. A comparison of the new species with the others in the group indicates that this group is less homogeneous than traditionally believed.

  2. Methods for Performing Crosses in Setaria viridis, a New Model System for the Grasses (United States)

    Jiang, Hui; Barbier, Hugues; Brutnell, Thomas


    Setaria viridis is an emerging model system for C4 grasses. It is closely related to the bioenergy feed stock switchgrass and the grain crop foxtail millet. Recently, the 510 Mb genome of foxtail millet, S. italica, has been sequenced 1,2 and a 25x coverage genome sequence of the weedy relative S. viridis is in progress. S. viridis has a number of characteristics that make it a potentially excellent model genetic system including a rapid generation time, small stature, simple growth requirements, prolific seed production 3 and developed systems for both transient and stable transformation 4. However, the genetics of S. viridis is largely unexplored, in part, due to the lack of detailed methods for performing crosses. To date, no standard protocol has been adopted that will permit rapid production of seeds from controlled crosses. The protocol presented here is optimized for performing genetic crosses in S. viridis, accession A10.1. We have employed a simple heat treatment with warm water for emasculation after pruning the panicle to retain 20-30 florets and labeling of flowers to eliminate seeds resulting from newly developed flowers after emasculation. After testing a series of heat treatments at permissive temperatures and varying the duration of dipping, we have established an optimum temperature and time range of 48 °C for 3-6 min. By using this method, a minimum of 15 crosses can be performed by a single worker per day and an average of 3-5 outcross progeny per panicle can be recovered. Therefore, an average of 45-75 outcross progeny can be produced by one person in a single day. Broad implementation of this technique will facilitate the development of recombinant inbred line populations of S. viridis X S. viridis or S. viridis X S. italica, mapping mutations through bulk segregant analysis and creating higher order mutants for genetic analysis. PMID:24121645

  3. The Use of Maleic Hydrazide for Effective Hybridization of Setaria viridis.

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    Govinda Rizal

    Full Text Available An efficient method for crossing green foxtail (Setaria viridis is currently lacking. S. viridis is considered to be the new model plant for the study of C4 system in monocots and so an effective crossing protocol is urgently needed. S. viridis is a small grass with C4-NADP (ME type of photosynthesis and has the advantage of having small genome of about 515 Mb, small plant stature, short life cycle, multiple tillers, and profuse seed set, and hence is an ideal model species for research. The objectives of this project were to develop efficient methods of emasculation and pollination, and to speed up generation advancement. We assessed the response of S. viridis flowers to hot water treatment (48°C and to different concentrations of gibberellic acid, abscisic acid, maleic hydrazide (MH, and kinetin. We found that 500 μM of MH was effective in the emasculation of S. viridis, whilst still retaining the receptivity of the stigma to pollination. We also report effective ways to accelerate the breeding cycle of S. viridis for research through the germination of mature as well as immature seeds in optimized culture media. We believe these findings will be of great interest to researchers using Setaria.

  4. Interferência interespecífica entre Amaranthus hybridus L. e Amaranthus viridis L. Interspecific interference between Amaranthus hybridus L. and Amaranthus viridis L.

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    Angela Maria Maluf


    Full Text Available O objetivo deste trabalho foi estudar a interferência interespecífica entre duas espécies de Amaranthus -- A. viridis e A. hybridus ¾, esta última com dois biótipos distintos (verde e roxo; ambas ocorriam associadas em dois locais. Nas populações de cada local foram feitos ensaios de substituição independentes, em vasos, nos quais observou-se que as populações que germinam mais prontamente são as que vencem em competição, ou seja, se estabelecem e produzem maior número de sementes. Houve tendência de A. hybridus (tipo verde dominar tanto A. hybridus (tipo roxo como A. viridis, e de A. hybridus (tipo roxo dominar A. viridis. Em cultivo misto, houve casos em que as espécies estavam competindo pelos mesmos recursos, ou explorando recursos diferentes do ambiente, ou mesmo com antagonismo mútuo.The objective of this paper was to study the interspecific interference between two Amaranthus species -- A. viridis and A. hybridus --, the latter with two distinct biotypes (green and purple; both species ocurred in two localities. In the populations of each of the locations, some independent substitution trials were made in pots, and it could be concluded that the populations that germinate more readily are those which are superior in competition i.e., those that establish themselves and produce the largest number of seeds. There was a tendency for A. hybridus (green biotype to dominate both A. hybridus (purple biotype and A. viridis, and for A. hybridus (purple biotype to dominate A. viridis. In mixed stands, there were cases where the species were competing for the same resources, cases where they were exploiting different environmental resources, and even cases of mutual antagonism.

  5. Ecological consequence of the introduction of the polychaete Marenzelleria cf. viridis into a shallow-water biotope of the northern Baltic Sea (United States)

    Kotta, Jonne; Orav, Helen; Sandberg-Kilpi, Eva


    Effects of the North American polychaete Marenzelleria cf. viridis on a simple shallow-water benthic community of the northern Baltic Sea were studied in a field experiment combining natural densities of dominating macrofaunal species. The presence of M. cf. viridis increased benthic production (chlorophyll a) and reduced the survival of the native polychaete Nereis diversicolor. Adult Macoma balthica caused a significant mortality on M. cf. viridis whereas adult Cerastoderma glaucum had no effect on M. cf. viridis. We suggest that the competitive interactions between M. cf. viridis and M. balthica are a possible key factor determining the distribution pattern of M. cf. viridis in the Baltic Sea.

  6. A new diketopiperazine heterodimer from an endophytic fungus Aspergillus niger. (United States)

    Li, Xiao-Bin; Li, Yue-Lan; Zhou, Jin-Chuan; Yuan, Hui-Qing; Wang, Xiao-Ning; Lou, Hong-Xiang


    One new diketopiperazine heterodimer, asperazine A (1), and eight known compounds, asperazine (2), cyclo(d-Phe-l-Trp) (3), cyclo(l-Trp-l-Trp) (4), 4-(hydroxymethyl)-5,6-dihydro-pyran-2-one (5), walterolactone A (6), and campyrones A-C (7-9), were isolated from an endophytic fungus Aspergillus niger. Their structures were determined unequivocally on the basis of extensive spectroscopic data analysis. This is the first report of the presence of compound 3 as a natural product. Cytotoxicity test against human cancer cell lines PC3, A2780, K562, MBA-MD-231, and NCI-H1688 revealed that compounds 1 and 2 had weak activities.

  7. Genetic characterization of Perna viridis L. in peninsular Malaysia using microsatellite markers

    Indian Academy of Sciences (India)

    C. C. Ong; K. Yusoff; C. K. Yap; S. G. Tan


    A total of 19 polymorphic microsatellite loci were used to analyse levels of genetic variation for 10 populations of Perna viridis L. collected from all over peninsular Malaysia. The populations involved in this study included Pulau Aman in Penang, Tanjung Rhu in Kedah, Bagan Tiang in Perak, Pulau Ketam in Selangor, Muar, Parit Jawa, Pantai Lido and Kampung Pasir Puteh in Johore, and Kuala Pontian and Nenasi in Pahang state. The number of alleles per locus ranged from two to seven, with an average of 3.1. Heterozygote deficiencies were observed across all the 10 populations. Characterization of the populations revealed that local populations of P. viridis in peninsular Malaysia were genetically similar enough to be used as a biomonitoring agent for heavy metal contamination in the Straits of Malacca. Cluster analysis grouped the P. viridis populations according to their geographical distributions with the exception of Parit Jawa. The analysis also revealed that P. viridis from the northern parts of peninsular Malaysia were found to be the most distant populations among the populations of mussels investigated and P. viridis from the eastern part of peninsular Malaysia were closer to the central and southern populations than to the northern populations.

  8. Setaria viridis floral-dip: A simple and rapid Agrobacterium-mediated transformation method

    Directory of Open Access Journals (Sweden)

    Polyana Kelly Martins


    Full Text Available Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements that make it suitable for use as a model plant. We report an alternative method of S. viridis transformation using floral dip to circumvent the necessity of tissue culture phase for transgenic plant regeneration. S. viridis spikes at boot stage were selected to be immersed in Agrobacterium suspension. T1 seeds could be identified in 1.5–2 months after floral dipping. We demonstrated through molecular analysis and RFP expression that seeds and resulting plants from dipped inflorescences were transformed. Our results suggest the feasibility of S. viridis floral dip transformation as a time-saving and cost-effective compared with traditional methods. To our knowledge, this is the first report using floral dip in S. viridis as an Agrobacterium-mediated transformation method.

  9. Macrobenthic community response to the Marenzelleria viridis (Polychaeta) invasion of a Danish estuary

    DEFF Research Database (Denmark)

    Delefosse, Matthieu; Banta, Gary; Canal Vergés, Paula;


    In the context of increasing biological invasions, we investigated the invasion of the non-native polychaete Marenzelleria viridis in a shallow Danish estuary, Odense Fjord. Three datasets with different spatial and temporal resolution were examined to describe the invasion of M. viridis and to i...

  10. Macrobenthic community response to the Marenzelleria viridis (Polychaeta) invasion of a Danish estuary

    DEFF Research Database (Denmark)

    Delefosse, Matthieu; Banta, Gary Thomas; Canal Vergés, Paula;


    We investigated the invasion of the non-native polychaete Marenzelleria viridis in a shallow Danish estuary, Odense Fjord. Three datasets with different spatial and temporal resolution were examined to describe the invasion of M. viridis and to investigate its effect on the native benthic communi...

  11. Complete genome sequence of Saccharomonospora viridis type strain (P101T)

    Energy Technology Data Exchange (ETDEWEB)

    Pati, Amrita; Sikorski, Johannes; Nolan, Matt; Lapidus, Alla; Copeland, Alex; Glavina Del Rio, Tijana; Lucas, Susan; Chen, Feng; Tice, Hope; Pitluck, Sam; Cheng, Jan-Fang; Chertkov, Olga; Brettin, Thomas; Han, Cliff; Detter, John C.; Kuske, Cheryl; Bruce, David; Goodwin, Lynne; Chain, Patrick; D' haeseleer, Patrik; Chen, Amy; Palaniappan, Krishna; Ivanova, Natalia; Mavromatis, Konstantinos; Mikhailova, Natalia; Rohde, Manfred; Tindall, Brian J.; Goker, Markus; Bristow, Jim; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Kyrpides1, Nikos C.; Klenk, Hans-Peter


    Saccharomonospora viridis (Schuurmans et al. 1956) Nonomurea and Ohara 1971 is the type species of the genus Saccharomonospora which belongs to the family Pseudonocardiaceae. S. viridis is of interest because it is a Gram-negative organism classified amongst the usually Gram-positive actinomycetes. Members of the species are frequently found in hot compost and hay, and its spores can cause farmer?s lung disease, bagassosis, and humidifier fever. Strains of the species S. viridis have been found to metabolize the xenobiotic pentachlorophenol (PCP). The strain described in this study has been isolated from peat-bog in Ireland. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of the family Pseudonocardiaceae, and the 4,308,349 bp long single replicon genome with its 3906 protein-coding and 64 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  12. A simple and highly efficient Agrobacterium-mediated transformation protocol for Setaria viridis

    Directory of Open Access Journals (Sweden)

    Polyana Kelly Martins


    Full Text Available The production and use of sugarcane in Brazil is very important for bioenergy production and is recognized as one of the most efficient in the world. In our laboratory, Setaria viridis is being tested as a model plant for sugarcane. S. viridis has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements that make it suitable for use as a model system. We report a highly efficient protocol for Agrobacterium-mediated genetic transformation of S. viridis. The optimization of several steps in tissue culture allowed the rapid regeneration of plants and increased the rate of transformation up to 29%. This protocol could become a powerful tool for functional genomics in sugarcane.

  13. Growth parameters in the cultured green mussel Perna viridis L. from the Zuari Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Sreepada, R.A.; Parulekar, A.H.

    Growth parameters for both length and weight were estimated in the raft-grown population of Perna viridis. The asymptotic length (L approaches infinity) and weight (W ) were computed to be 85 mm and 34.37 g respectively. Theoretical length...

  14. Oxygen dynamics and porewater transport in sediments inhabited by the invasive polychaete Marenzelleria viridis

    DEFF Research Database (Denmark)

    Jovanovic, Zeljko; Larsen, Morten; Quintana, Cintia Organo;


    The polychaete Marenzelleria viridis is an invasive species and often replaces the native Nereis diversicolor. This shift leads to more reduced conditions and changes in the biogeochemical function of the sediments. By combining imaging techniques for O2 (planar optodes) and irrigation patterns (...

  15. The jewel anemone corynactis viridis, a new order for the Netherlands Cnidaria: Corallimorpharia)

    NARCIS (Netherlands)

    Gittenberger, A.; Schrieken, A.; Coolen, J.W.P.; Vlierhuis, W.


    During an expedition with scuba-divers to the Dutch part of the Brown Ridge in the central North Sea in June 2013, two colonies of the jewel anemone Corynactis viridis were found on the wreck Anna Graebe. With the jewel anemone both a new species and a new animal order, the Corallimorpharia, are add

  16. The juwel anemone Corynactis viridis, a new order for the Netherlands (Cnidaria: Corallimorpharia)

    NARCIS (Netherlands)

    Gittenberger, A.; Schrieken, N.; Coolen, J.W.P.; Vlierhuis, W.


    During an expedition with scuba-divers to the Dutch part of the Brown Ridge in the central North Sea in June 2013, two colonies of the jewel anemone Corynactis viridis were found on the wreck Anna Graebe. With the jewel anemone both a new species and a new animal order, the Corallimorpharia, are add

  17. Transcriptomic responses of Perna viridis embryo to Benzo(a)pyrene exposure elucidated by RNA sequencing. (United States)

    Jiang, Xiu; Qiu, Liguo; Zhao, Hongwei; Song, Qinqin; Zhou, Hailong; Han, Qian; Diao, Xiaoping


    The green mussel Perna viridis is an ideal biomonitor to evaluate marine environmental pollution. Benzo(a)pyrene (BaP) is a typical polycyclic aromatic hydrocarbon (PAH), which is well known for the mutagenic and carcinogenic characteristics. However, the toxicological effects of BaP on Perna viridis embryo are still unclear. In this study, we investigated the embryo transcriptomic profile of Perna viridis treated with BaP via digital gene expression analysis. A total of 92,362,742 reads were produced from two groups (control and BaP exposure) by whole transcriptome sequencing (RNA-Seq). Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis were used on all genes to determine the biological functions and processes. Genes involved in various molecular pathways of toxicological effects were enriched further. The differential expression genes (DEGs) were related to stress response, infectious disease and innate immunity. Quantitative real-time PCR (qRT-PCR) measured expressional levels of six genes confirmed through the DGE analysis. This study reveals that RNA-seq for transcriptome profiling of P. viridis embryo can better understand the embryo toxic effects of BaP. Furthermore, it also suggests that RNA-seq is a superior tool for generating novel and valuable information for revealing the toxic effects caused by BaP at transcriptional level.

  18. Response of DNA, proteins, lipids and antioxidant enzymes as measure of toxicity to mercury exposures in green mussel Perna viridis

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    Studies on exposures of gills of green-lipped mussel Perna viridis to sublethal levels of mercury (Hg) indicates that oxidative stress marker like lipids peroxidation and protein carbonyl content increase. With the exception of superoxide dismutase...

  19. Complete mitochondrial genomes of the three brown algae (Heterokonta : Phaeophyceae) Dictyota dichotoma, Fucus vesiculosus and Desmarestia viridis

    NARCIS (Netherlands)

    Secq, MPO; Goer, SL; Stam, WT; Olsen, JL; Oudot-LeSecq, M.-P.


    We report the complete mitochondrial sequences of three brown algae (Dictyota dichotoma, Fucus vesiculosus and Desmarestia viridis) belonging to three phaeophycean lineages. They have circular mapping organization and contain almost the same set of mitochondrial genes, despite their size differences

  20. Growth differentiation factor 9:bone morphogenetic protein 15 heterodimers are potent regulators of ovarian functions (United States)

    Peng, Jia; Li, Qinglei; Wigglesworth, Karen; Rangarajan, Adithya; Kattamuri, Chandramohan; Peterson, Randall T.; Eppig, John J.; Thompson, Thomas B.; Matzuk, Martin M.


    The TGF-β superfamily is the largest family of secreted proteins in mammals, and members of the TGF-β family are involved in most developmental and physiological processes. Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), oocyte-secreted paralogs of the TGF-β superfamily, have been shown genetically to control ovarian physiology. Although previous studies found that GDF9 and BMP15 homodimers can modulate ovarian pathways in vitro, the functional species-specific significance of GDF9:BMP15 heterodimers remained unresolved. Therefore, we engineered and produced purified recombinant mouse and human GDF9 and BMP15 homodimers and GDF9:BMP15 heterodimers to compare their molecular characteristics and physiological functions. In mouse granulosa cell and cumulus cell expansion assays, mouse GDF9 and human BMP15 homodimers can up-regulate cumulus expansion-related genes (Ptx3, Has2, and Ptgs2) and promote cumulus expansion in vitro, whereas mouse BMP15 and human GDF9 homodimers are essentially inactive. However, we discovered that mouse GDF9:BMP15 heterodimer is ∼10- to 30-fold more biopotent than mouse GDF9 homodimer, and human GDF9:BMP15 heterodimer is ∼1,000- to 3,000-fold more bioactive than human BMP15 homodimer. We also demonstrate that the heterodimers require the kinase activities of ALK4/5/7 and BMPR2 to activate SMAD2/3 but unexpectedly need ALK6 as a coreceptor in the signaling complex in granulosa cells. Our findings that GDF9:BMP15 heterodimers are the most bioactive ligands in mice and humans compared with homodimers explain many puzzling genetic and physiological data generated during the last two decades and have important implications for improving female fertility in mammals. PMID:23382188

  1. Synthesis, morphological control, and antibacterial properties of hollow/solid Ag2S/Ag heterodimers

    KAUST Repository

    Pang, Maolin


    Ag2S and Ag are important functional materials that have received considerable research interest in recent years. In this work, we develop a solution-based synthetic method to combine these two materials into hollow/solid Ag2S/Ag heterodimers at room temperature. Starting from monodisperse Cu2O solid spheres, CuS hollow spheres can be converted from Cu2O through a modified Kirkendall process, and the obtained CuS can then be used as a solid precursor for preparation of the Ag2S/Ag heterodimers through ion exchange and photo-assisted reduction. We have found that formation of the Ag2S/Ag heterodimers is instantaneous, and the size of Ag nanocrystals on the hollow spheres of Ag2S can be controlled by changing the concentration and power of reducing agents in the synthesis. The growth of Ag nanoparticles on hollow spheres of Ag2S in the dimers is along the [111] direction of the silver crystal; the light absorption properties have also been investigated. Furthermore, coupling or tripling of Ag2S/Ag heterodimers into dumbbell-like trimers ((Ag 2S)2/Ag, linear) and triangular tetramers ((Ag 2S)3/Ag, coplanar) can also be attained at 60°C by adding the bidentate ligand ethylenediamine as a cross-linking agent. To test the applicability of this highly asymmetric dipolar composite, photocatalytic inactivation of Escherichia coli K-12 in the presence of the as-prepared Ag 2S/Ag heterodimers has been carried out under UV irradiation. The added Ag2S/Ag heterodimers show good chemical stability under prolonged UV irradiation, and no appreciable solid dissolution is found. Possible mechanisms regarding the enhanced antibacterial activity have also been addressed. © 2010 American Chemical Society.

  2. Fluorescence resonance energy transfer imaging reveals that chemokine-binding modulates heterodimers of CXCR4 and CCR5 receptors.

    Directory of Open Access Journals (Sweden)

    Nilgun Isik

    Full Text Available BACKGROUND: Dimerization has emerged as an important feature of chemokine G-protein-coupled receptors. CXCR4 and CCR5 regulate leukocyte chemotaxis and also serve as a co-receptor for HIV entry. Both receptors are recruited to the immunological synapse during T-cell activation. However, it is not clear whether they form heterodimers and whether ligand binding modulates the dimer formation. METHODOLOGY/PRINCIPAL FINDINGS: Using a sensitive Fluorescence Resonance Energy Transfer (FRET imaging method, we investigated the formation of CCR5 and CXCR4 heterodimers on the plasma membrane of live cells. We found that CCR5 and CXCR4 exist as constitutive heterodimers and ligands of CCR5 and CXCR4 promote different conformational changes within these preexisting heterodimers. Ligands of CCR5, in contrast to a ligand of CXCR4, induced a clear increase in FRET efficiency, indicating that selective ligands promote and stabilize a distinct conformation of the heterodimers. We also found that mutations at C-terminus of CCR5 reduced its ability to form heterodimers with CXCR4. In addition, ligands induce different conformational transitions of heterodimers of CXCR4 and CCR5 or CCR5(STA and CCR5(Delta4. CONCLUSIONS/SIGNIFICANCE: Taken together, our data suggest a model in which CXCR4 and CCR5 spontaneously form heterodimers and ligand-binding to CXCR4 or CCR5 causes different conformational changes affecting heterodimerization, indicating the complexity of regulation of dimerization/function of these chemokine receptors by ligand binding.

  3. Perdas causadas por Coccus viridis (Hemiptera: Coccidae em mudas de Coffea arabica L.

    Directory of Open Access Journals (Sweden)

    Flávio Lemes Fernandes


    Full Text Available Coccus viridis (Green danifica plantas jovens e adultas de Coffea arabica Linnaeu. No entanto, nada se sabe sobre a magnitude dos danos causados por esta praga. Assim, este trabalho teve por objetivo estudar as relações entre o ataque de C. viridis e as perdas causadas por este inseto a C. arabica. Este trabalho foi conduzido em casa de vegetação na Universidade Federal de Viçosa. Foram utilizadas sementes da linhagem IAC 15 da variedade “Catuaí vermelho” de café (C. arabica. Para a confecção dos tratamentos esta praga foi criada em casa de vegetação separada do experimento. Os tratamentos foram: plantas infestadas e não infestadas por adultos e ninfas da cochonilha verde. As plantas foram nutridas com solução nutritiva. Durante 110 dias foram avaliados: números de adultos e de ninfas de primeiro, segundo e terceiro ínstares, área foliar, diâmetro do caule, altura das plantas em todas repetições. No final do experimento avaliou-se o peso das raízes, caule, folhas e total. Os pesos das raízes, matéria seca total, área foliar e diâmetro do caule de plantas não atacadas por C. viridis superaram em 1,31; 1,41; 1,50 e 8,93 vezes, respectivamente o peso de plantas atacadas. As variáveis selecionadas foram: diâmetro do caule (cm, área foliar (cm², peso de raízes (g, ninfas, adultos e total das cochonilhas. Concluindo que a planta de C. arabica é afetada de forma diferente entre seus órgãos e que a ninfa de terceiro ínstar e adultos são as fases que mais causam danos a C. arabica.Losses Caused by Coccus viridis (Green (Hemiptera: Coccidae on Seedlings of Coffea arabica L.Abstract. Coccus viridis (Green cause losses on seedling and old plants of Coffea arabica (Green. However, nothing is known about of the damages caused by this pest. Thus, the objective of this work was to evaluate the relations between atack of C. viridis and the losses caused by this insect. on C. arabica. This work was conduced in greenhouse at

  4. Proteomic profile in Perna viridis after exposed to Prorocentrum lima, a dinoflagellate producing DSP toxins. (United States)

    Huang, Lu; Zou, Ying; Weng, Hui-wen; Li, Hong-Ye; Liu, Jie-Sheng; Yang, Wei-Dong


    In the current study, we compared protein profiles in gills of Perna viridis after exposure to Prorocentrumlima, a dinoflagellate producing DSP toxins, and identified the differential abundances of protein spots using 2D-electrophoresis. After exposure to P. lima, the level of okadaic acid (a main component of DSP toxins) in gills of P. viridis significantly increased at 6 h, but mussels were all apparently healthy without death. Among the 28 identified protein spots by MALDI TOF/TOF-MS, 12 proteins were up-regulated and 16 were down-regulated in the P. lima-exposed mussels. These identified proteins were involved in various biological activities, such as metabolism, cytoskeleton, signal transduction, response to oxidative stress and detoxification. Taken together, our results indicated that the presence of P. lima caused DSP toxins accumulation in mussel gill, and might consequently induce cytoskeletonal disorganization,oxidative stress, a dysfunction in metabolism and ubiquitination/proteasome activity.

  5. Water chemistry influences the toxicity of silver to the green-lipped mussel Perna viridis. (United States)

    Vijayavel, Kannappan


    The study determined the influence and relative importance of water chemistry parameters (pH, alkalinity, hardness) on the acute toxicity of silver to the green mussel Perna viridis. A preliminary bioassay revealed that 4 mg L(-1) of silver caused 50% mortality (LC50) in 96 h for mussels placed in seawater with pH 8.5, hardness 1,872 mg L(-1), and alkalinity 172 mg L(-1). Mortality of mussels increased with decreasing pH and increasing hardness and alkalinity variables. In contrast the mortality decreased with increasing pH and decreasing hardness and alkalinity values. The water chemistry also affected the concentration of silver in experimental seawater and bioaccumulation of silver in mussels. The results revealed that the chemical properties of seawater must be considered while conducting toxicity tests with metals like silver. The possible explanations for the influence of water chemistry on silver toxicity to P. viridis are discussed.

  6. Roles of Aquaporins in Setaria viridis Stem Development and Sugar Storage

    Directory of Open Access Journals (Sweden)

    Samantha Alison McGaughey


    Full Text Available Setaria viridis is a C4 grass used as a model for bioenergy feedstocks. The elongating internodes in developing S. viridis stems grow from an intercalary meristem at the base, and progress acropetally towards fully expanded cells that store sugar. During stem development and maturation, water flow is a driver of cell expansion and sugar delivery. As aquaporin proteins are implicated in regulating water flow we analysed elongating and mature internode transcriptomes to identify putative aquaporin encoding genes that had particularly high transcript levels during the distinct stages of internode cell expansion and maturation. We observed that SvPIP2;1 was highly expressed in internode regions undergoing cell expansion, and SvNIP2;2 was highly expressed in mature sugar accumulating regions. Gene co-expression analysis revealed SvNIP2;2 expression was highly correlated with the expression of five putative sugar transporters expressed in the S. viridis internode. To explore the function of the proteins encoded by SvPIP2;1 and SvNIP2;2 we expressed them in Xenopus laevis oocytes and tested their permeability to water. SvPIP2;1 and SvNIP2;2 functioned as water channels in X. laevis oocytes and their permeability was gated by pH. Our results indicate that SvPIP2;1 may function as a water channel in developing stems undergoing cell expansion and SvNIP2;2 is a candidate for retrieving water and possibly a yet to be determined solute from mature internodes. Future research will investigate whether changing the function of these proteins influences stem growth and sugar yield in S. viridis.

  7. Disseminated Mycobacterium celatum infection in a white-tailed trogon (Trogon viridis)

    DEFF Research Database (Denmark)

    Bertelsen, M. F.; Grondahl, C.; Giese, Steen Bjørck


    An adult female white-tailed trogon (Trogon viridis) was presented with abdominal enlargement and hard subcutaneous masses. Necropsy findings included bony masses extending from skeletal structures, disseminated pale foci in the liver, and a pale mass in the kidney. Histological examination...... revealed multifocal to coalescing granulomatous inflammation in the bone, liver, kidney, lung and spleen. Mycobacterium celatum was isolated from the liver and identified by DNA sequencing. This is the first report of M. celatum infection in an avian species....

  8. Occurrence of the alien nudibranch Melibe viridis (Kelaart, 1858) (Opisthobranchia, Tethydidae), in the Maltese Islands


    J.A. BORG; J. Evans; P. J. Schembri


    The alien dendronotacean nudibranch Melibe viridis (Kelaart, 1858), a tropical Indo-Pacific species that seems to have been introduced by shipping into the Mediterranean via the Suez Canal, and which has established populations in Greece, Turkey, Cyprus, Montenegro, Croatia, NW Sicily, southern peninsular Italy and Djerba Island in the Gulf of Gabes, is recorded for the first time from Malta. A thriving population was observed on a soft sediment bottom at a depth of 18-20 m off the western co...

  9. Observations on white and yellow venoms from an individual southern Pacific rattlesnake (Crotalus viridis helleri). (United States)

    Johnson, E K; Kardong, K V; Ownby, C L


    Biochemical differences in white and yellow venoms produced in the separate venom glands of an individual southern Pacific rattlesnake (Crotalus viridis helleri) were investigated. Compared to the yellow venom, the white venom contained fewer low molecular weight components and was considerably less toxic. Although the exact LD50 was not determined, the white venom did not produce toxic effects in mice when injected i.v. at concentrations up to 10 mg/kg. The i.v. LD50 of the yellow venom was approximately 1.6 mg/kg. Both white and yellow venoms had hemorrhagic activity, but the white venom caused less intradermal hemorrhage in mice. No L-amino acid oxidase activity was measured in the white venom and protease and phospholipase A2 activities of the white venom were much less than in the yellow venom. The white and yellow venoms both produced myonecrosis at 1, 3 and 24 hr after i.m. injection into mice, however, there were some qualitative differences in the myonecrosis produced. When the venom samples were reacted against Wyeth's polyvalent (Crotalidae) antivenom using immunodiffusion, three precipitin bands formed against the yellow venom, whereas only one formed against the white venom. When reacted against an antiserum to myotoxin alpha from C. viridis viridis venom, both the white and yellow venoms produced one precipitin band each.

  10. Symbiosis in the green leafhopper, Cicadella viridis (Hemiptera, Cicadellidae). Association in statu nascendi? (United States)

    Michalik, Anna; Jankowska, Władysława; Kot, Marta; Gołas, Aniela; Szklarzewicz, Teresa


    The green leafhopper, Cicadella viridis lives in symbiotic association with microorganisms. The ultrastructural and molecular analyses have shown that in the body of the C. viridis two types of bacteriocyte endosymbionts are present. An amplification and sequencing of 16S rRNA genes revealed that large, pleomorphic bacteria display a high similarity (94-100%) to the endosymbiont 'Candidatus Sulcia muelleri' (phylum Bacteroidetes), whereas long, rod-shaped microorganisms are closely related to the γ-proteobacterial symbiont Sodalis (97-99% similarity). Both endosymbionts may be harbored in their own bacteriocytes as well as may co-reside in the same bacteriocytes. The ultrastructural observations have revealed that the Sodalis-like bacteria harboring the same bacteriocytes as bacterium Sulcia may invade the cells of the latter. Bacteria Sulcia and Sodalis-like endosymbionts are transovarially transmitted from one generation to the next. However, Sodalis-like endosymbionts do not invade the ovaries individually, but only inside Sulcia cells. Apart from bacteriocyte endosymbionts, in the body of C. viridis small, rod-shaped bacteria have been detected, and have been identified as being closely related to γ-proteobacterial microorganism Pectobacterium (98-99% similarity). The latter are present in the sheath cells of the bacteriomes containing bacterium Sulcia as well as in fat body cells.

  11. Has Aeshna viridis EVERSMANN, 1836 (Odonata: Aeshnidae really disappeared from southern Poland (East-Central Europe?

    Directory of Open Access Journals (Sweden)

    Buczyński Paweł


    Full Text Available 50-100 years ago the southern boundary of the distribution area of Aeshna viridis ran through southern Poland. However, no records of this species from this area have been reported since then. The species is therefore considered as having retreated northwards. The present research disclosed three new sites of A. viridis on the edge of or just beyond its historical distribution area: one in south-western Poland (Trestno: 51°04’N, 17º08’E and two in the south-east of the country (Krasiczyn: 49º46’N, 22º38’E, Bolestraszyce: 49º49’N, 22º51’E. All the sites were anthropogenic. This demonstrates the survival of a number of populations and the formation of new ones in water bodies formed de novo or to which Stratiotes aloides was introduced artificially. This suggests that the conservation of A. viridis is possible in this region.

  12. Interaction of Temperature and Photoperiod Increases Growth and Oil Content in the Marine Microalgae Dunaliella viridis.

    Directory of Open Access Journals (Sweden)

    Soundarya Srirangan

    Full Text Available Eukaryotic marine microalgae like Dunaliella spp. have great potential as a feedstock for liquid transportation fuels because they grow fast and can accumulate high levels of triacylgycerides with little need for fresh water or land. Their growth rates vary between species and are dependent on environmental conditions. The cell cycle, starch and triacylglycerol accumulation are controlled by the diurnal light:dark cycle. Storage compounds like starch and triacylglycerol accumulate in the light when CO2 fixation rates exceed the need of assimilated carbon and energy for cell maintenance and division during the dark phase. To delineate environmental effects, we analyzed cell division rates, metabolism and transcriptional regulation in Dunaliella viridis in response to changes in light duration and growth temperatures. Its rate of cell division was increased under continuous light conditions, while a shift in temperature from 25 °C to 35 °C did not significantly affect the cell division rate, but increased the triacylglycerol content per cell several-fold under continuous light. The amount of saturated fatty acids in triacylglycerol fraction was more responsive to an increase in temperature than to a change in the light regime. Detailed fatty acid profiles showed that Dunaliella viridis incorporated lauric acid (C12:0 into triacylglycerol after 24 hours under continuous light. Transcriptome analysis identified potential regulators involved in the light and temperature-induced lipid accumulation in Dunaliella viridis.

  13. Assessment of pollution in road runoff using a Bufo viridis biological assay

    Energy Technology Data Exchange (ETDEWEB)

    Dorchin, A., E-mail: [Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa 31905 (Israel); Shanas, U., E-mail: [Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa 31905 (Israel); Department of Biology, Faculty of Natural sciences, University of Haifa - Oranim, Tiv' on 36006 (Israel)


    Road runoff is a major source of environmental pollution, significantly threatening nearby aquatic habitats. Chemical analyses indicate high pollutant concentrations in the road's 'first flush', but bioassays are more advantageous for addressing the cumulative effects of the numerous pollutants within the runoff. We used Bufo viridis embryos and larvae to assess the toxicity of road runoff from two major highways in Israel. We show, for the first time, that exposure to midseason runoff not only has an adverse effect on growth and development rates of B. viridis larvae but can also lead to increased rates of morphological deformations. Seasonal first flushes, despite having higher metal concentrations, did not adversely affect the toad larvae, apparently due to a counter effect of organic matter that potentially served as a supplementary energy resource. Road runoff can be a major cause for a qualitative decrease in the quality of aquatic habitats threatening amphibians in Israel. - Highway runoff has detrimental effects on the development of B. viridis larvae.

  14. Setaria viridis as a model system to advance millet genetics and genomics

    Directory of Open Access Journals (Sweden)

    Pu Huang


    Full Text Available Millet is a common name for a group of polyphyletic, small-seeded cereal crops that include pearl, finger and foxtail millet. Millet species are an important source of calories for many societies, often in developing countries. Compared to major cereal crops such as rice and maize, millets are generally better adapted to dry and hot environments. Despite their food security value, the genetic architecture of agronomically important traits in millets, including both morphological traits and climate resilience remains poorly studied. These complex traits have been challenging to dissect in large part because of the lack of sufficient genetic tools and resources. In this article, we review the phylogenetic relationship among various millet species and discuss the value of a genetic model system for millet research. We propose that a broader adoption of green foxtail (Setaria viridis as a model system for millets could greatly accelerate the pace of gene discovery in the millets, and summarize available and emerging resources in S. viridis and its domesticated relative S. italica. These resources have value in forward genetics, reverse genetics and high throughput phenotyping. We describe methods and strategies to best utilize these resources to facilitate the genetic dissection of complex traits. We envision that coupling cutting-edge technologies and the use of S. viridis for gene discovery will accelerate genetic research in millets in general. This will enable strategies and provide opportunities to increase productivity, especially in the semi-arid tropics of Asia and Africa where millets are staple food crop.

  15. Tomato gamma-glutamylhydrolases: expression, characterization, and evidence for heterodimer formation. (United States)

    Akhtar, Tariq A; McQuinn, Ryan P; Naponelli, Valeria; Gregory, Jesse F; Giovannoni, James J; Hanson, Andrew D


    Folates typically have gamma-linked polyglutamyl tails that make them better enzyme substrates and worse transport substrates than the unglutamylated forms. The tail can be shortened or removed by the vacuolar enzyme gamma-glutamyl hydrolase (GGH). It is known that GGH is active only as a dimer and that plants can have several GGH genes whose homodimeric products differ functionally. However, it is not known whether GGH dimers dissociate under in vivo conditions, whether heterodimers form, or how heterodimerization impacts enzyme activity. These issues were explored using the GGH system of tomato (Solanum lycopersicum). Tomato has three GGH genes that, like those in other eudicots, apparently diverged recently. LeGGH1 and LeGGH2 are expressed in fruit and all other organs, whereas LeGGH3 is expressed mainly in flower buds. LeGGH1 and LeGGH2 homodimers differ in bond cleavage preference; the LeGGH3 homodimer is catalytically inactive. Homodimers did not dissociate in physiological conditions. When coexpressed in Escherichia coli, LeGGH1 and LeGGH2 formed heterodimers with an intermediate bond cleavage preference, whereas LeGGH3 formed heterodimers with LeGGH1 or LeGGH2 that had one-half the activity of the matching homodimer. E. coli cells expressing LeGGH2 showed approximately 85% reduction in folate polyglutamates, but cells expressing LeGGH3 did not, confirming that LeGGH2 can function in vivo and LeGGH3 cannot. The formation of LeGGH1-LeGGH2 heterodimers was demonstrated in planta using bimolecular fluorescence complementation. Plant GGH heterodimers thus appear to form wherever different GGH genes are expressed simultaneously and to have catalytic characteristics midway between those of the corresponding homodimers.

  16. Seasonal variation of oxidative biomarkers in gills and digestive gland of green-lipped mussel Perna viridis from Arabian Sea (United States)

    Verlecar, X. N.; Jena, K. B.; Chainy, G. B. N.


    Investigations on seasonal variation in oxidative stress biomarkers were carried out on the natural population of green-lipped mussel Perna viridis collected from Bambolim beach area of Goa. Oxidative stress indices such as lipid peroxidation (LPX), hydrogen peroxide (H 2O 2), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione transferase (GST), glutathione reductase (GR), reduced glutathione (GSH) and ascorbic acid (ASA) were measured in gills and digestive gland of P. viridis during February, May, August and November. The present study reveals two important aspects regarding the antioxidant defence status of tissues of P. viridis. Firstly, antioxidant capacity of tissues of P. viridis exhibits seasonal variation. Secondly, various components of antioxidant capacity such as oxidative stress markers, levels of antioxidant enzymes and small antioxidant molecules vary differently in tissues with respect to different seasons. Although the oxidative stress status of gills and digestive gland of P. viridis expressed in terms of LPX and H 2O 2 was the lowest in February, its level was maximal in gills and digestive gland during May and November, respectively. While activities of SOD and GPX of tissues of P. viridis were found to be low in August, activities of CAT and GR were recorded to be low in February. GST activity in gills although remained high in February, in digestive gland elevated values were recorded in August and November. A seasonal variation in the levels of small antioxidant molecules was also noticed. Among non enzymatic antioxidants ASA content of tissues was maximal in May and August in comparison to February and November, but GSH remained high in November. It therefore appears that environmental factors may play a crucial role in regulating the oxidative stress capacity of tissues of P. viridis.


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    Abdurahman F.I.


    Full Text Available This study is aimed at determining the proximate content, concentration of some micro/macro elements and the phytochemistry of Ocimum viridis (scent leafs and Ocimum gratissimum (jaw’s mallow leafs with the view of updating its usage in orthodox and herbal medicine by man in the treatment of dysentery, diarrhea and wound healing. The leaves sampled of Ocimum viridis and Ocimum gratissimum were collected from Zannari, Jere L.G.A, Borno state, Nigeria. The proximate analysis was carried out using methods of Association of Analytical Chemist and the results showed that Ocimum viridis has higher dry matter (99.70%, crude protein (12.48%, Nitrogen free extract (2.03%, Ash (6.5% and fats (7.0%. While carbohydrate (83.40%, crude fibre (45.50% and moisture content (0.4% were estimated to be higher in Ocimum gratissimum. The levels of eight (8 elements (Ca, F, Cu, Cr, Mn, Zn, Fe, and Pb were determined using Atomic Absorption Spectrophotometry. The results revealed higher concentration in Ocimum gratissimum except for iron and manganese concentration which are higher of the elements understudy in Ocimum viridis only the lead was not detected in the samples by the methodology employed for the analysis. The concentration of anions (nitrates, phosphates and sulphates was estimated using the Smart Spectro Spectrophotometer. It shows that, Ocimum viridis has higher concentration of 11.08 mg/g and 7.04 mg/g in nitrates and sulphates respectively. And Ocimum gratissimum has higher concentration of phosphates 6.28 mg/g. The phytochemicals and some heavy and trace elements as well as a few anions were evaluated using standard procedures. The phytochemical screening of both the fresh and dry leafs revealed the presence of very high cardiac glycosides and the flavonoids, terpenoids, saponins, tannins and carbohydrates shows difference in variation of the leafs. And alkaloids were found to be absence in both fresh and dry leafs. The elemental content obtained

  18. Interactions of a Pop5/Rpp1 heterodimer with the catalytic domain of RNase MRP. (United States)

    Perederina, Anna; Khanova, Elena; Quan, Chao; Berezin, Igor; Esakova, Olga; Krasilnikov, Andrey S


    Ribonuclease (RNase) MRP is a multicomponent ribonucleoprotein complex closely related to RNase P. RNase MRP and eukaryotic RNase P share most of their protein components, as well as multiple features of their catalytic RNA moieties, but have distinct substrate specificities. While RNase P is practically universally found in all three domains of life, RNase MRP is essential in eukaryotes. The structural organizations of eukaryotic RNase P and RNase MRP are poorly understood. Here, we show that Pop5 and Rpp1, protein components found in both RNase P and RNase MRP, form a heterodimer that binds directly to the conserved area of the putative catalytic domain of RNase MRP RNA. The Pop5/Rpp1 binding site corresponds to the protein binding site in bacterial RNase P RNA. Structural and evolutionary roles of the Pop5/Rpp1 heterodimer in RNases P and MRP are discussed.

  19. Production in Pichia pastoris of protein-based polymers with small heterodimer-forming blocks. (United States)

    Domeradzka, Natalia E; Werten, Marc W T; de Vries, Renko; de Wolf, Frits A


    Some combinations of leucine zipper peptides are capable of forming α-helical heterodimeric coiled coils with very high affinity. These can be used as physical cross-linkers in the design of protein-based polymers that form supramolecular structures, for example hydrogels, upon mixing solutions containing the complementary blocks. Such two-component physical networks are of interest for many applications in biomedicine, pharmaceutics, and diagnostics. This article describes the efficient secretory production of A and B type leucine zipper peptides fused to protein-based polymers in Pichia pastoris. By adjusting the fermentation conditions, we were able to significantly reduce undesirable proteolytic degradation. The formation of A-B heterodimers in mixtures of the purified products was confirmed by size exclusion chromatography. Our results demonstrate that protein-based polymers incorporating functional heterodimer-forming blocks can be produced with P. pastoris in sufficient quantities for use in future supramolecular self-assembly studies and in various applications.

  20. Fano resonance assisting plasmonic circular dichroism from nanorice heterodimers for extrinsic chirality

    CERN Document Server

    Hu, Li; Fang, Liang; Chen, Guo; Wei, Hua; Fang, Yurui


    In this work, the circular dichroisms (CD) of nanorice heterodimers consisting of two parallel arranged nanorices with the same size but different materials are investigated theoretically. Symmetry-breaking is introduced by using different materials and oblique incidence to achieve strong CD at the vicinity of Fano resonance peaks. We demonstrate that all Au-Ag heterodimers exhibit multipolar Fano resonances and strong CD effect. A simple quantitative analysis shows that the structure with larger Fano asymmetry factor has stronger CD. The intensity and peak positions of the CD effect can be flexibly tuned in a large range by changing particle size, shape, the inter-particle distance and surroundings. Furthermore, CD spectra exhibit high sensitivity to ambient medium in visible and near infrared regions. Our results here are beneficial for the design and application of high sensitive CD sensors and other related fields.

  1. Proton transfer in histidine-tryptophan heterodimers embedded in helium droplets

    CERN Document Server

    Bellina, Bruno; Kresin, Vitaly V


    We used cold helium droplets as nano-scale reactors to form and ionize, by electron bombardment and charge transfer, aromatic amino acid heterodimers of histidine with tryptophan, methyl-tryptophan, and indole. The molecular interaction occurring through an N-H...N hydrogen bond leads to a proton transfer from the indole group of tryptophan to the imidazole group of histidine in a radical cationic environment.

  2. Proton transfer in histidine-tryptophan heterodimers embedded in helium droplets

    Energy Technology Data Exchange (ETDEWEB)

    Bellina, Bruno; Merthe, Daniel J.; Kresin, Vitaly V. [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484 (United States)


    We used cold helium droplets as nano-scale reactors to form and ionize, by electron bombardment and charge transfer, aromatic amino acid heterodimers of histidine with tryptophan, methyl-tryptophan, and indole. The molecular interaction occurring through an N–H ⋅ ⋅ ⋅ N hydrogen bond leads to a proton transfer from the indole group of tryptophan to the imidazole group of histidine in a radical cationic environment.

  3. P-glycoprotein expression in Perna viridis after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins. (United States)

    Huang, Lu; Wang, Jie; Chen, Wen-Chang; Li, Hong-Ye; Liu, Jie-Sheng; Tao Jiang; Yang, Wei-Dong


    Bivalves naturally exposed to toxic algae have mechanisms to prevent from harmful effects of diarrhetic shellfish poisoning (DSP) toxins. However, quite few studies have examined the mechanisms associated, and the information currently available is still insufficient. Multixenobiotic resistance (MXR) is ubiquitous in aquatic invertebrates and plays an important role in defense against xenobiotics. Here, to explore the roles of P-glycoprotein (P-gp) in the DSP toxins resistance in shellfish, complete cDNA of P-gp gene in the mussel Perna viridis was cloned and analyzed. The accumulation of okadaic acid (OA), a main component of DSP toxins, MXR activity and expression of P-gp in gills of P. viridis were detected after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins in the presence or absence of P-gp inhibitors PGP-4008, verapamil (VER) and cyclosporin A (CsA). The mussel P. viridis P-gp closely matches MDR/P-gp/ABCB protein from various organisms, having a typical sequence organization as full transporters from the ABCB family. After exposure to P. lima, OA accumulation, MXR activity and P-gp expression significantly increased in gills of P. viridis. The addition of P-gp-specific inhibitors PGP-4008 and VER decreased MXR activity induced by P. lima, but had no effect on the OA accumulation in gills of P. viridis. However, CsA, a broad-spectrum inhibitor of ABC transporter not only decreased MXR activity, but also increased OA accumulation in gills of P. viridis. Together with the ubiquitous presence of other ABC transporters such as MRP/ABCC in bivalves and potential compensatory mechanism in P-gp and MRP-mediated resistance, we speculated that besides P-gp, other ABC transporters, especially MRP might be involved in the resistance mechanisms to DSP toxins.

  4. Binary Toxin Subunits of Lysinibacillus sphaericus Are Monomeric and Form Heterodimers after In Vitro Activation.

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    Wahyu Surya

    Full Text Available The binary toxin from Lysinibacillus sphaericus has been successfully used for controlling mosquito-transmitted diseases. An activation step shortens both subunits BinA and BinB before their interaction with membranes and internalization in midgut cells, but the precise role of this activation step is unknown. Herein, we show conclusively using three orthogonal biophysical techniques that protoxin subunits form only monomers in aqueous solution. However, in vitro activated toxins readily form heterodimers. This oligomeric state did not change after incubation of these heterodimers with detergent. These results are consistent with the evidence that maximal toxicity in mosquito larvae is achieved when the two subunits, BinA and BinB, are in a 1:1 molar ratio, and directly link proteolytic activation to heterodimerization. Formation of a heterodimer must thus be necessary for subsequent steps, e.g., interaction with membranes, or with a suitable receptor in susceptible mosquito species. Lastly, despite existing similarities between BinB C-terminal domain with domains 3 and 4 of pore-forming aerolysin, no aerolysin-like SDS-resistant heptameric oligomers were observed when the activated Bin subunits were incubated in the presence of detergents or lipidic membranes.

  5. Density regulation in toad populations (Epidalea calamita, Bufotes viridis) by differential winter survival of juveniles. (United States)

    Sinsch, Ulrich; Schäfer, Alena M


    The size of amphibian populations varies considerably between years, so that systematic trends in dynamics are difficult to detect. Informed conservation management of presumably declining populations requires the identification of the most sensitive life stage. In temperate-zone anurans there is growing evidence that juveniles hibernating for the first time suffer from substantial winter losses. In two syntopic toads (Epidalea calamita, Bufotes viridis) we monitored survival of such juveniles during four consecutive winters in the natural habitat and in four temperature treatments (3°, 5 °C, 10°/15 °C or 20 °C, natural light-dark cycle) in temperature-controlled chambers during winter. Specifically, we tested the hypotheses that (1) winter mortality of juvenile toads which hibernate for the first time in their life is an important component of population dynamics, and that (2) mortality rates differed between the two species. Parameters quantified were size-dependent winter mortality and body condition of pre- and post-hibernating juveniles. Field data provided evidence for the important role of winter mortality of first-hibernators in population dynamics. Choice of hibernacula differed in E. calamita between small and medium-sized individuals and also between the two species suggesting distinct mortality risks. The inability of small E. calamita to reach frost-proof hibernacula by burrowing, and the exposure of small B. viridis to predators are the most probable causes of size-assortative winter mortality. In conclusion, E. calamita juveniles may benefit from rising average winter temperatures in the future by decreased risk of freezing to death, whereas predator-caused winter mortality of B. viridis juveniles will also depend on the effects of climate warming on predator phenology.

  6. Is Echinometra viridis facilitating a phase shift on an Acropora cervicornis patch reef in Belize? (United States)

    Stefanic, C. M.; Greer, L.; Norvell, D.; Benson, W.; Curran, H.


    Coral reef health is in rapid decline across the Caribbean due to a number of anthropogenic and natural disturbances. A phase shift from coral- to macroalgae-dominant reefs is pervasive and has been well documented. Acropora cervicornis (Staghorn Coral) has been particularly affected by this shift due to mass mortality of this species since the 1980s. In recent years few Caribbean A. cervicornis refugia have been documented. This study characterizes the relationship between coral and grazing urchins on a rare patch reef system dominated by A. cervicornis off the coast of Belize. To assess relative abundance of live A. cervicornis and the urchin Echinometra viridis, photographs and urchin abundance data were collected from 132 meter square quadrats along five transects across the reef. Photographs were digitized and manually segmented using Adobe Illustrator, and percent live coral cover and branch tip densities were calculated using Matlab. Mean percent live coral cover across all transects was 24.4 % with a high of 65% live coral per meter square. Average urchin density was 18.5 per quadrat, with an average density per transect ranging from 22.1 to 0.5 per quadrat. Up to over 400 live A. cervicornis branch tips per quadrat were observed. Data show a positive correlation between E. viridis abundance and live A. cervicornis, suggesting that these urchins are facilitating recovery or persistence of this endangered coral species. These results suggest the relationship between E. viridis and A. cervicornis could be a key element in a future reversal of the coral to macroalgae phase shift on some Caribbean coral reefs.

  7. Karyological and flow cytometric evidence of triploid specimens in Bufo viridis (Amphibia Anura

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    D Cavallo


    Full Text Available Karyological and flow cytometric (FCM analyses were performed on a group of 14 green toads of the Bufo viridis species from seven Eurasian populations. Both approaches gave concordant results concerning the DNA ploidy level. All the populations examined were represented exclusively by diploid or tetraploid specimens, except one, where triploids were found. Results evidenced an interpopulation variability in DNA content against the same ploidy level, as well as an unusually high number of triploids in a particular reproductive place. The origin of polyploidy and the presence and persistence of a high number of triploids in a particular population are discussed.

  8. A theoretical study of electronic excited states of photosynthetic reaction center in Rhodopseudomonas viridis

    Institute of Scientific and Technical Information of China (English)

    REN; Yanliang; CHENG; Lin; WAN; Jian; LI; Yongjian; LIU; Junjun; YANG; Guangfu; ZHANG; Lihua; YANG; Song


    The electronic singlet vertical excited states of photosynthetic reaction center (PSRC) in Rhodopseudomonas (Rps.) viridis were investigated by ZINDO and INDO/S methods. The effects of the interactions of pigment-pigment and pigment-protein on the electronic excitations were examined. The calculation results showed that the interactions of pigment-pigment and pigment-protein play an important role in reasonably assigning the experimental absorption and circular dichroism (CD) spectra of PSRC in Rps. virids. By comparing the theoretically computed excited states with the experimental absorption and CD spectra, satisfactory assignments of the experimental spectroscopic peaks were achieved.

  9. Inhibition of In Vivo Growth of Plasmodium berghei by Launaea taraxacifolia and Amaranthus viridis in Mice (United States)

    Olorunnisola, Olubukola S.; Adegbola, Peter


    Launaea taraxacifolia and Amaranthus viridis used by people of Western Africa in the treatment of malaria and related symptoms were assessed for their antiplasmodial value against the chloroquine sensitive strain of Plasmodium berghei. Crude extracts (200 mg/kg) and chloroquine (5 mg/kg) were administered to different groups of Swiss mice. The percentage of parasitemia, survival time, and haematological parameters were determined. Both extracts significantly (p phytochemical investigations in the search for new and locally affordable antimalarial agents. PMID:28050307

  10. A serine protease inhibitor from hemolymph of green mussel, Perna viridis

    Digital Repository Service at National Institute of Oceanography (India)

    Khan, M.S.; Goswami, U.; Rojatkar, S.R.; Khan, M.I.

    . Bioorganic & Medicinal Chemistry Letters 18 (2008) 3963–3967 Contents lists available el E-mail address: (M.I. Khan). of these have acted as pharmacophores or templates from which therapeutically useful agents have been designed. In fact... novel molecule 1 has been found 102.5 and 97.1–104.68lM, Van’t Hoff analysis showed of the inhibitor is entropically Bioorganic & Medicinal journal homepage: www. rights reserved. of green mussel, Perna viridis a, * 411 008, India cell-free hemolymph...

  11. Volatile oil analysis of spruce galls caused by Sacchiphantes viridis Ratz.

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    Alicja Miszta


    Full Text Available The results of the analysis of volatile oil obtained from galls caused by Sacchiphantes viridis are presented in this paper. It was found that galls contain more oil than normal shoots. The composition of the oil obtained from galls differs significantly from that of normal shoots. The differences observed in the amount of camphene. β-pinene, myrcene, 3-carene, unidentinfied compounds 14 and 17, camphor, fenchyl alcohol, borneol and citronellol seem to be connected with the deterioration of central resin canals in the stem cortex during the development of galls and with the formation of new and very numerous canals in the bases of the differentiated gall leaves.

  12. Heavy metals in bivalves collected from river estuaries of Thailand. [Perna viridis

    Energy Technology Data Exchange (ETDEWEB)

    Menasveta, P.; Cheevapora, V.; Wongwit, C.


    This investigation was undertaken to determine the levels of lead, zinc, copper, cadmium, and mercury in five species of bivalves collected from six river estuaries of Thailand during July 1978 to January 1979. The in situ bioassay for studying heavy metals uptake by green mussels (Perna viridis) was also conducted at the Chao Phraya river estuary during February 1980 to March 1981. The results revealed high contamination of lead in mussels during the period of river run-off. The factors that might contribute to this incidence were discussed. Contaminations of the other four metals in bivalves did not show great variation and they were still within the acceptable limits.

  13. Occurrence of the alien nudibranch Melibe viridis (Kelaart, 1858 (Opisthobranchia, Tethydidae, in the Maltese Islands

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    J.A. BORG


    Full Text Available The alien dendronotacean nudibranch Melibe viridis (Kelaart, 1858, a tropical Indo-Pacific species that seems to have been introduced by shipping into the Mediterranean via the Suez Canal, and which has established populations in Greece, Turkey, Cyprus, Montenegro, Croatia, NW Sicily, southern peninsular Italy and Djerba Island in the Gulf of Gabes, is recorded for the first time from Malta. A thriving population was observed on a soft sediment bottom at a depth of 18-20 m off the western coast of the island of Comino (Maltese Islands. It is suggested that this species was introduced into Malta due to a natural range expansion of surrounding populations.

  14. Modulation of antioxidant defences in digestive gland of Perna viridis (L.), on mercury exposures

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    also reported increased GR activity in rat renal tissue under in vivo Hg stress. A significant positive correlation between GR and GSH seen presently also supports that enzyme is involved reducing the oxidative stress (r = 0.571, P < 0.05). GSH... 18, 773–781. Lakshmanan, P.T., Nambisan, P.N.K., 1989. Bioaccumulation and depuration of some trace metals in the mussel, Perna viridis (Linnaeus). Bull. Environ. Contam. Toxicol. 43, 131–138. Lash, L.H., Zalups, R.K., 1996. Alterations in renal...

  15. A taxonomic review of the Dark-winged Trumpeter Psophia viridis (Aves: Gruiformes: Psophiidae

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    Marina Oppenheimer


    Full Text Available The Dark-winged Trumpeter, Psophia viridis (Gruiformes, Psophiidae is a Brazilian endemic species and includes three subspecies: Psophia viridis viridis Spix, 1825; Psophia v. dextralis Conover, 1934, and Psophia v. obscura Pelzeln, 1857, as well as P. v. interjecta Griscom & Greenway, 1937, whose validity has been questioned by several authors. These taxa are allopatric in distribution along the south of the Amazon River, although the precise limits of their distribution still remain unknown. This complex has never been taxonomically reviewed and this work aims to test the validity of its taxa based on the Phylogenetic Species Concept. Morphometrical characters and plumage colour patterns were analyzed, and the distribution of the taxa was also revised. In this study, 108 specimens from 41 localities were examined (all types included, with each reliable literature-based locality being included in order to delimit the geographical distribution of the complex. Morphometrical data did not point out significant differences between the taxa, also showing no sexual dimorphism among them. Meanwhile, plumage characters showed consistent and distinct patterns for each of the taxa, except for P. v. interjecta, whose features indicated by authors as diagnosable are the result of individual variation. No clinal variation or intergradation were observed, even at regions close to the rivers headwaters, where supposedly populations could be in contact. It is suggested that the currently accepted subspecies be elevated to the species level, such as: Psophia viridis Spix, 1825, distributed in the Madeira-Tapajós interfluvium, P. dextralis, found in the Tapajós-Tocantins interfluvium, and P. obscura, which occurs from the right bank of the Tocantins River to the west of the State of Maranhão.Os jacamins-de-costas-verdes, Psophia viridis (Gruiformes, Psophiidae são endêmicos da Amazônia brasileira e contam, atualmente, com três subespécies reconhecidas

  16. Acquired phototrophy through retention of functional chloroplasts increases growth efficiency of the sea slug Elysia viridis.

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    Finn A Baumgartner

    Full Text Available Photosynthesis is a fundamental process sustaining heterotrophic organisms at all trophic levels. Some mixotrophs can retain functional chloroplasts from food (kleptoplasty, and it is hypothesized that carbon acquired through kleptoplasty may enhance trophic energy transfer through increased host growth efficiency. Sacoglossan sea slugs are the only known metazoans capable of kleptoplasty, but the relative fitness contributions of heterotrophy through grazing, and phototrophy via kleptoplasts, are not well understood. Fitness benefits (i.e. increased survival or growth of kleptoplasty in sacoglossans are commonly studied in ecologically unrealistic conditions under extended periods of complete darkness and/or starvation. We compared the growth efficiency of the sacoglossan Elysia viridis with access to algal diets providing kleptoplasts of differing functionality under ecologically relevant light conditions. Individuals fed Codium fragile, which provide highly functional kleptoplasts, nearly doubled their growth efficiency under high compared to low light. In contrast, individuals fed Cladophora rupestris, which provided kleptoplasts of limited functionality, showed no difference in growth efficiency between light treatments. Slugs feeding on Codium, but not on Cladophora, showed higher relative electron transport rates (rETR in high compared to low light. Furthermore, there were no differences in the consumption rates of the slugs between different light treatments, and only small differences in nutritional traits of algal diets, indicating that the increased growth efficiency of E. viridis feeding on Codium was due to retention of functional kleptoplasts. Our results show that functional kleptoplasts from Codium can provide sacoglossan sea slugs with fitness advantages through photosynthesis.

  17. Anti-HMG-CoA Reductase, Antioxidant, and Anti-Inflammatory Activities of Amaranthus viridis Leaf Extract as a Potential Treatment for Hypercholesterolemia

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    Shamala Salvamani


    Full Text Available Inflammation and oxidative stress are believed to contribute to the pathology of several chronic diseases including hypercholesterolemia (elevated levels of cholesterol in blood and atherosclerosis. HMG-CoA reductase inhibitors of plant origin are needed as synthetic drugs, such as statins, which are known to cause adverse effects on the liver and muscles. Amaranthus viridis (A. viridis has been used from ancient times for its supposedly medically beneficial properties. In the current study, different parts of A. viridis (leaf, stem, and seed were evaluated for potential anti-HMG-CoA reductase, antioxidant, and anti-inflammatory activities. The putative HMG-CoA reductase inhibitory activity of A. viridis extracts at different concentrations was determined spectrophotometrically by NADPH oxidation, using HMG-CoA as substrate. A. viridis leaf extract revealed the highest HMG-CoA reductase inhibitory effect at about 71%, with noncompetitive inhibition in Lineweaver-Burk plot analysis. The leaf extract showed good inhibition of hydroperoxides, 2,2-diphenyl-1-picrylhydrazyl (DPPH, nitric oxide (NO, and ferric ion radicals in various concentrations. A. viridis leaf extract was proven to be an effective inhibitor of hyaluronidase, lipoxygenase, and xanthine oxidase enzymes. The experimental data suggest that A. viridis leaf extract is a source of potent antioxidant and anti-inflammatory agent and may modulate cholesterol metabolism by inhibition of HMG-CoA reductase.

  18. Modulation of antioxidant and biotransformation enzymes in the gills of Perna viridis (L.) exposed to water accomodate fraction of diesel

    Digital Repository Service at National Institute of Oceanography (India)

    Jena, K.B.; Verlecar, X.N.; Chainy, G.B.N.

    Investigations on the effect of oils on the oxidative stress and antioxidant molecules in gills of Perna viridis were carried out under controlled laboratory conditions. For this purpose water accommodate fraction of diesel oil at 0.5 arid 5% were...

  19. Engineering of Immunoglobulin Fc Heterodimers Using Yeast Surface-Displayed Combinatorial Fc Library Screening.

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    Hye-Ji Choi

    Full Text Available Immunoglobulin Fc heterodimers, which are useful scaffolds for the generation of bispecific antibodies, have been mostly generated through structure-based rational design methods that introduce asymmetric mutations into the CH3 homodimeric interface to favor heterodimeric Fc formation. Here, we report an approach to generate heterodimeric Fc variants through directed evolution combined with yeast surface display. We developed a combinatorial heterodimeric Fc library display system by mating two haploid yeast cell lines, one haploid cell line displayed an Fc chain library (displayed FcCH3A with mutations in one CH3 domain (CH3A on the yeast cell surface, and the other cell line secreted an Fc chain library (secreted FcCH3B with mutations in the other CH3 domain (CH3B. In the mated cells, secreted FcCH3B is displayed on the cell surface through heterodimerization with the displayed FcCH3A, the detection of which enabled us to screen the library for heterodimeric Fc variants. We constructed combinatorial heterodimeric Fc libraries with simultaneous mutations in the homodimer-favoring electrostatic interaction pairs K370-E357/S364 or D399-K392/K409 at the CH3 domain interface. High-throughput screening of the libraries using flow cytometry yielded heterodimeric Fc variants with heterodimer-favoring CH3 domain interface mutation pairs, some of them showed high heterodimerization yields (~80-90% with previously unidentified CH3 domain interface mutation pairs, such as hydrogen bonds and cation-π interactions. Our study provides a new approach for engineering Fc heterodimers that could be used to engineer other heterodimeric protein-protein interactions through directed evolution combined with yeast surface display.

  20. Engineering of Immunoglobulin Fc Heterodimers Using Yeast Surface-Displayed Combinatorial Fc Library Screening. (United States)

    Choi, Hye-Ji; Kim, Ye-Jin; Choi, Dong-Ki; Kim, Yong-Sung


    Immunoglobulin Fc heterodimers, which are useful scaffolds for the generation of bispecific antibodies, have been mostly generated through structure-based rational design methods that introduce asymmetric mutations into the CH3 homodimeric interface to favor heterodimeric Fc formation. Here, we report an approach to generate heterodimeric Fc variants through directed evolution combined with yeast surface display. We developed a combinatorial heterodimeric Fc library display system by mating two haploid yeast cell lines, one haploid cell line displayed an Fc chain library (displayed FcCH3A) with mutations in one CH3 domain (CH3A) on the yeast cell surface, and the other cell line secreted an Fc chain library (secreted FcCH3B) with mutations in the other CH3 domain (CH3B). In the mated cells, secreted FcCH3B is displayed on the cell surface through heterodimerization with the displayed FcCH3A, the detection of which enabled us to screen the library for heterodimeric Fc variants. We constructed combinatorial heterodimeric Fc libraries with simultaneous mutations in the homodimer-favoring electrostatic interaction pairs K370-E357/S364 or D399-K392/K409 at the CH3 domain interface. High-throughput screening of the libraries using flow cytometry yielded heterodimeric Fc variants with heterodimer-favoring CH3 domain interface mutation pairs, some of them showed high heterodimerization yields (~80-90%) with previously unidentified CH3 domain interface mutation pairs, such as hydrogen bonds and cation-π interactions. Our study provides a new approach for engineering Fc heterodimers that could be used to engineer other heterodimeric protein-protein interactions through directed evolution combined with yeast surface display.

  1. Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent

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    Rael Horwitz


    Full Text Available Ocean acidification (OA is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments—the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone’s tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data

  2. Molecular mechanism of the allosteric regulation of the αγ heterodimer of human NAD-dependent isocitrate dehydrogenase (United States)

    Ma, Tengfei; Peng, Yingjie; Huang, Wei; Ding, Jianping


    Human NAD-dependent isocitrate dehydrogenase catalyzes the decarboxylation of isocitrate (ICT) into α-ketoglutarate in the Krebs cycle. It exists as the α2βγ heterotetramer composed of the αβ and αγ heterodimers. Previously, we have demonstrated biochemically that the α2βγ heterotetramer and αγ heterodimer can be allosterically activated by citrate (CIT) and ADP. In this work, we report the crystal structures of the αγ heterodimer with the γ subunit bound without or with different activators. Structural analyses show that CIT, ADP and Mg2+ bind adjacent to each other at the allosteric site. The CIT binding induces conformational changes at the allosteric site, which are transmitted to the active site through the heterodimer interface, leading to stabilization of the ICT binding at the active site and thus activation of the enzyme. The ADP binding induces no further conformational changes but enhances the CIT binding through Mg2+-mediated interactions, yielding a synergistic activation effect. ICT can also bind to the CIT-binding subsite, which induces similar conformational changes but exhibits a weaker activation effect. The functional roles of the key residues are verified by mutagenesis, kinetic and structural studies. Our structural and functional data together reveal the molecular mechanism of the allosteric regulation of the αγ heterodimer. PMID:28098230

  3. Dissociation and trafficking of rat GABAB receptor heterodimer upon chronic capsaicin stimulation. (United States)

    Laffray, Sophie; Tan, Kelly; Dulluc, Josette; Bouali-Benazzouz, Rabia; Calver, Andrew R; Nagy, Frédéric; Landry, Marc


    Gamma-aminobutyric acid type B receptors (GABAB) are G-protein-coupled receptors that mediate GABAergic inhibition in the brain. Their functional expression is dependent upon the formation of heterodimers between GABAB1 and GABAB2 subunits, a process that occurs within the endoplasmic reticulum. However, the mechanisms that regulate GABAB receptor oligomerization at the plasma membrane remain largely unknown. We first characterized the functional cytoarchitecture of an organotypic co-culture model of rat dorsal root ganglia and spinal cord. Subsequently, we studied the interactions between GABAB subunits after chronic stimulation of sensory fibres with capsaicin. Surface labelling of recombinant proteins showed a decrease in subunit co-localization and GABAB2 labelling, after capsaicin treatment. In these conditions, fluorescence lifetime imaging measurements further demonstrated a loss of interactions between green fluorescent protein-GABAB1b and t-dimer discosoma sp red fluorescent protein-GABAB2 subunits. Finally, we established that the GABAB receptor undergoes clathrin-dependent internalization and rapid recycling to the plasma membrane following activation with baclofen, a GABAB agonist. However, in cultures chronically stimulated with capsaicin, the agonist-induced endocytosis was decreased, reflecting changes in the dimeric state of the receptor. Taken together, our results indicate that the chronic stimulation of sensory fibres can dissociate the GABAB heterodimer and alters its responsiveness to the endogenous ligand. Chronic stimulation thus modulates receptor oligomerization, providing additional levels of control of signalling.

  4. Subunits of the Drosophila actin-capping protein heterodimer regulate each other at multiple levels.

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    Ana Rita Amândio

    Full Text Available The actin-Capping Protein heterodimer, composed of the α and β subunits, is a master F-actin regulator. In addition to its role in many cellular processes, Capping Protein acts as a main tumor suppressor module in Drosophila and in humans, in part, by restricting the activity of Yorkie/YAP/TAZ oncogenes. We aimed in this report to understand how both subunits regulate each other in vivo. We show that the levels and capping activities of both subunits must be tightly regulated to control F-actin levels and consequently growth of the Drosophila wing. Overexpressing capping protein α and β decreases both F-actin levels and tissue growth, while expressing forms of Capping Protein that have dominant negative effects on F-actin promote tissue growth. Both subunits regulate each other's protein levels. In addition, overexpressing one of the subunit in tissues knocked-down for the other increases the mRNA and protein levels of the subunit knocked-down and compensates for its loss. We propose that the ability of the α and β subunits to control each other's levels assures that a pool of functional heterodimer is produced in sufficient quantities to restrict the development of tumor but not in excess to sustain normal tissue growth.

  5. Subunits of the Drosophila actin-capping protein heterodimer regulate each other at multiple levels. (United States)

    Amândio, Ana Rita; Gaspar, Pedro; Whited, Jessica L; Janody, Florence


    The actin-Capping Protein heterodimer, composed of the α and β subunits, is a master F-actin regulator. In addition to its role in many cellular processes, Capping Protein acts as a main tumor suppressor module in Drosophila and in humans, in part, by restricting the activity of Yorkie/YAP/TAZ oncogenes. We aimed in this report to understand how both subunits regulate each other in vivo. We show that the levels and capping activities of both subunits must be tightly regulated to control F-actin levels and consequently growth of the Drosophila wing. Overexpressing capping protein α and β decreases both F-actin levels and tissue growth, while expressing forms of Capping Protein that have dominant negative effects on F-actin promote tissue growth. Both subunits regulate each other's protein levels. In addition, overexpressing one of the subunit in tissues knocked-down for the other increases the mRNA and protein levels of the subunit knocked-down and compensates for its loss. We propose that the ability of the α and β subunits to control each other's levels assures that a pool of functional heterodimer is produced in sufficient quantities to restrict the development of tumor but not in excess to sustain normal tissue growth.

  6. Development of fibre and parenchyma cells in the bamboo Phyllostachys viridi-glaucescens

    CERN Document Server

    Crow, E


    The development of the shoot apex and the ontogeny of fibre and parenchyma cells in elongating shoots of the bamboo Phyllostachys viridi-glaucescens (Carr.) Riv. and Riv., seen under the light microscope is described. Fibre cells differentiated from cells of the procambium, whilst the parenchyma cells differentiated from cells of the primary thickening meristem which surround the procambium strands. Three stages of early fibre and parenchyma cell development were identified and these are referred to in subsequent studies of cell wall development. The cytology of developing internodal fibre and parenchyma cells seen under the transmission electron microscope (TEM) is described. There were few ultrastructural features to distinguish the two cell types. Thiery's PATAg test was performed to identify organelles which may be associated with the synthesis of polysaccharides destined for the cell wall. The ultrastructural results are discussed in terms of the process of cell wall deposition. Observations were made of...

  7. Chloride transport in toad skin (Bufo viridis). The effect of salt adaptation

    DEFF Research Database (Denmark)

    Katz, U; Larsen, Erik Hviid


    The steady-state Cl- current across the skin of Bufo viridis adapted to tap water was found to be rectified. In skins bathed with NaCl Ringer on both sides, a large outward current, carried by influx of Cl-, was observed at a clamping voltage (V) of less than -50 mV (outside of the skin negative......, and apparent leakage conductance was reduced. Application of the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine to skin of fully salt-adapted toads increased the transepithelial Cl- conductance, and the time courses of voltage clamp currents became more like those of water-adapted toads. Apparent...... leakage conductance was increased.(ABSTRACT TRUNCATED AT 400 WORDS)...

  8. Establishing the thermal threshold of the tropical mussel Perna viridis in the face of global warming. (United States)

    Goh, B P L; Lai, C H


    With increasing recognition that maximum oxygen demand is the unifying limit in tolerance, the first line of thermal sensitivity is, as a corollary, due to capacity limitations at a high level of organisational complexity before individual, molecular or membrane functions become disturbed. In this study the tropical mussel Perna viridis were subjected to temperature change of 0.4 °C per hour from ambient to 8-36 °C. By comparing thermal mortality against biochemical indices (hsp70, gluthathione), physiological indices (glycogen, FRAP, NRRT) and behavioural indices (clearance rate), a hierarchy of thermal tolerance was therein elucidated, ranging from systemic to cellular to molecular levels. Generally, while biochemical indices indicated a stress signal much earlier than the more integrated behavioural indices, failure of the latter (indicating a tolerance limit and transition to pejus state) occurred much earlier than the other indices tending towards thermal extremities at both ends of the thermal spectrum.

  9. Morphological, behavioral and biological aspects of Azya luteipes Mulsant fed on Coccus viridis (Green

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    Juliana Nais


    Full Text Available One of the major pests of nursery seedlings of coffee (Coffea arabica L. is the green scale, Coccus viridis (Green (Hemiptera: Coccidae. The main predators of this species are beetles of the family Coccinellidae, especially Azya luteipes Mulsant. Morphological, behavioral and biological aspects of A. luteipes feeding on C. viridis on coffee plants were examined under laboratory conditions. Tests were conducted in room temperature at 28 ± 2 ºC. A. luteipes oviposits on the underside of the scale's body, laying two to four eggs per insect. The eggs have a subelliptical form and a white-clear color, and the incubation period is 8.3 ± 1.2 days. The number of eggs laid per female per day varies between eight and ten. A. luteipes undergoes four larval instars with durations of 2.0 ± 0, 3.2 ± 0.5, 3.6 ± 0.5 and 4.6 ± 0 days for the 1st, 2nd, 3rd and 4th instars, respectively. The average durations of the prepupal and pupal stages were 2.0 ± 0 and 10.9 ± 1.3 days, respectively. The viability of the larvae during each instar was 91.9, 89.3, 90.2 and 96.4 %, respectively, and the viabilities of prepupae and pupae were 99.1 and 98.2 %. The average duration of the egg-adult cycle was 34.3 ± 2.6 days, and the sex ratio was 0.52 %. Females presented a gray-colored head, while males presented a yellow head.

  10. Photosynthetic performance of Setaria viridis to soil drought and rewatering alternations

    Institute of Scientific and Technical Information of China (English)

    Ya Yong Luo; Xue Yong Zhao; RuiLian Zhou; YingXin Huang; XiaoAn Zuo


    The ability of psammophyte (a plant that grows in sand or sandy soil) to withstand and recover from severe droughts is crucial for desertifieation control and restoration of degraded vegetation in semi-arid sandy land in northern China. Responses of the photo-synthetic gas exchange and chlorophyll fluorescence of an annual (Setaria viridis) were measured through three cycles of soil drying and rewatering. Results showed that the net photosynthesis rate (Pn) decreased by 95 percent, 91 percent, and 61 percent at end of three drought periods; the stomatal conductance (gs) decreased by 72 percent, 73 percent, and 53 percent; the transpiration rate (Tr) decreased by 70 percent, 69 percent, and 37 percent; and water-use efficiency (WUE) decreased by 83 percent, 69 percent,and 38 percent. At the same time, the trapping probability with no dark adaptation (Fv'/FM') decreased by 70 percent, 12 percent,and 10 percent, while the electron transport per cross-section (ET0'/CS'0) decreased by 80 percent, 45 percent, and 13 percent. The intercellular CO2 (Ci) increased by 1.77, 1.02, and 0.66 times, and the dissipation per cross-section (DI0'/CS0') increased by 98 percent, 28 percent, and 22 percent. These results indicated that S. viridis was subjected to photoinhibition and some nonstomatal limitation of photosynthesis under drought. However, the above photosynthetic characteristics were restored to control values after three or four days of rewatering. The capability to recover from drought may contribute to the plant's use of water as efficiently as possible. Furthermore, during the subsequent drought spells, suppression of Pn, gs, Tr, Fv'/FM', and ET0'/CS0' decreased or slowed down following the drying and rewatering alternations, especially in the third drought spell.

  11. GABA(B2) is essential for g-protein coupling of the GABA(B) receptor heterodimer. (United States)

    Robbins, M J; Calver, A R; Filippov, A K; Hirst, W D; Russell, R B; Wood, M D; Nasir, S; Couve, A; Brown, D A; Moss, S J; Pangalos, M N


    GABA(B) receptors are unique among G-protein-coupled receptors (GPCRs) in their requirement for heterodimerization between two homologous subunits, GABA(B1) and GABA(B2), for functional expression. Whereas GABA(B1) is capable of binding receptor agonists and antagonists, the role of each GABA(B) subunit in receptor signaling is unknown. Here we identified amino acid residues within the second intracellular domain of GABA(B2) that are critical for the coupling of GABA(B) receptor heterodimers to their downstream effector systems. Our results provide strong evidence for a functional role of the GABA(B2) subunit in G-protein coupling of the GABA(B) receptor heterodimer. In addition, they provide evidence for a novel "sequential" GPCR signaling mechanism in which ligand binding to one heterodimer subunit can induce signal transduction through the second partner of a heteromeric complex.

  12. Changes in soil diversity and global activities following invasions of the exotic invasive plant, Amaranthus viridis L., decrease the growth of native sahelian Acacia species. (United States)

    Sanon, Arsene; Béguiristain, Thierry; Cébron, Aurelie; Berthelin, Jacques; Ndoye, Ibrahima; Leyval, Corinne; Sylla, Samba; Duponnois, Robin


    The objectives of this study were to determine whether the invasive plant Amaranthus viridis influenced soil microbial and chemical properties and to assess the consequences of these modifications on native plant growth. The experiment was conducted in Senegal at two sites: one invaded by A. viridis and the other covered by other plant species. Soil nutrient contents as well as microbial community density, diversity and functions were measured. Additionally, five sahelian Acacia species were grown in (1) soil disinfected or not collected from both sites, (2) uninvaded soil exposed to an A. viridis plant aqueous extract and (3) soil collected from invaded and uninvaded sites and inoculated or not with the arbuscular mycorrhizal (AM) fungus Glomus intraradices. The results showed that the invasion of A. viridis increased soil nutrient availability, bacterial abundance and microbial activities. In contrast, AM fungi and rhizobial development and the growth of Acacia species were severely reduced in A. viridis-invaded soil. Amaranthus viridis aqueous extract also exhibited an inhibitory effect on rhizobial growth, indicating an antibacterial activity of this plant extract. However, the inoculation of G. intraradices was highly beneficial to the growth and nodulation of Acacia species. These results highlight the role of AM symbiosis in the processes involved in plant coexistence and in ecosystem management programs that target preservation of native plant diversity.

  13. Degradation characteristics of toxic microcystis viridis by mastigophora, monas guttula using aquatic large scale microcosm; Ogata tansui microcosm wo mochiita benmochurui monas guttula ni yoru yudoku microcystis viridis no bunkai tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Iwami, N.; Matsumura, M. [University of Tsukuba, Ibaraki (Japan); Inamori, Y. [National Inst. for Environmental Studies, Tsukuba (Japan); Sugiura, N. [Ibaraki Prefectural Waterworks, Ibaraki (Japan)


    Mastigophora, monas guttula, is able to propagate even by using large aquatic microcosm. This mastigophora efficiently predated and degraded microcystis viridis producing toxic substance, microcystin, almost in the whole quantity in the wide water temperature range from 20{degree}C to 30{degree}C at which microcystis propagates and disappears in natural lakes. As a result of evaluating perdition and degradation effects of momas guttula by chlorophyll-a and COD, any of chlorophyll-a indicated a removal rate of more than 90% almost in a week, and microcystis-origin particle COD more than 80%. It was also found that three kinds of microcystin YR, LR, and RR which microcystis viridis produces are almost completely degraded. From these results, it was thought that perdation and degradation of microfauna like m. guttula can greatly contribute to degrading and disappearing toxic microcystis even in natural lakes. 21 refs., 9 figs., 2 tabs.

  14. Thirteen years on the hunt for Buxbaumia viridis in the Czech Republic: still on the tip of the iceberg?

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    Eva Holá


    Full Text Available Rare epixylic moss Buxbaumia viridis, which is one of the “Annex II” species of the European “Habitat directive”, has been recorded at 124 localities in the Czech Republic in course of the last 13 years. Most of them were discovered in the last five years following a dedicated search at both historical sites of occurrence and new localities with putatively suitable habitat conditions. The recent and historical area of occupancy and extent of occurrence are not obviously different, although most of the recent localities are concentrated in the Western Carpathians and the Hrubý Jeseník Mts. Surprisingly, only 38% of the localities are located in natural forest habitats, of which herb-rich and acidophilous beech forests were among the most commonly inhabited ones. The rest of occurrences were recorded in non-natural forests (habitats strongly influenced or created by man, particularly the coniferous forest plantations. Sufficient amount of decaying wood of the advanced decay stages, as well as sufficient and constant humidity are crucial prerequisites for the occurrence of B. viridis in both types of forests. True epixylic moss Herzogiella seligeri and the liverwort Chiloscyphus profundus were recorded as the most common associated species, while the rest of commonly co-occurring species were facultatively epixylic, ground or ubiquitous bryophytes; other specialized and rare epixylic mosses or liverworts were only rarely recorded. We also designed a potential distribution model for B. viridis based on the distribution of habitats most commonly occupied by the studied moss. Despite the simplicity of the model, its close match with the recent distribution in the Western Carpathians, the Hrubý Jeseník Mts. and Šumava Mts. supports its relevance for the real distribution of B. viridis.

  15. The effects of nutrients and secondary compounds of Coffea arabica on the behavior and development of Coccus viridis. (United States)

    Fernandes, F L; Picanço, M C; Fernandes, M E S; Queiroz, R B; Xavier, V M; Martinez, H E P


    Phytochemicals may modify the food quality, reduce a plant's palatability to insects, or defend against pests. This work aimed to study 1) relationships between the nitrogen and potassium levels given to plants in nutritive solutions and the foliar phytochemical concentrations, 2) the effect of nutrients and secondary compounds of Coffea arabica on the behavior of Coccus viridis, and 3) tolerance of C. arabica to losses. Deficient, normal, and excessive nitrogen and potassium fertilization treatments were used. Each treatment had two plants (one infested and one noninfested plant). The contents of phytochemicals in the infested plants' leaves and their dry matter of roots, stems, and leaves as well as the total contents in noninfested plants, were determined. The adults and nymphs of C. viridis were counted for 60 d in all treatments. It was verified that elevated nitrogen and potassium levels in the nutritional solutions led to increased of nymphs and adults of C. viridis to the coffee plants over time. Potassium and nitrogen had both direct and indirect effects on C. viridis. The direct effect was because of the increase of the nitrogen content in the leaves. The indirect effect instead was because of reductions in the caffeine and chlorogenic acid contents in the leaves. This is the first study to show relationship nutrient levels of coffee phytochemicals in response to herbivory by scale insects. Caffeine and chlorogenic acid applied on coffee leaves stimulated the locomotory activity of the green scale, thus reducing their feeding compared with untreated leaves. The elevation of caffeine and chlorogenic acid levels in coffee leaves affect this generalist insect by stimulating the locomotion of crawlers.

  16. Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis


    Aldo Nicosia; Teresa Maggio; Salvatore Mazzola; Angela Cuttitta


    Anemonia viridis is a widespread and extensively studied Mediterranean species of sea anemone from which a large number of polypeptide toxins, such as blood depressing substances (BDS) peptides, have been isolated. The first members of this class, BDS-1 and BDS-2, are polypeptides belonging to the β-defensin fold family and were initially described for their antihypertensive and antiviral activities. BDS-1 and BDS-2 are 43 amino acid peptides characterised by three disulfide bonds that act as...

  17. Predator-labeling effect on byssus production in marine mussels Perna viridis (L.) and Brachidontes variabilis (Krauss). (United States)

    Cheung, S G; Luk, K C; Shin, P K S


    Mussels Perna viridis and Brachidontes variabilis were exposed to chemical cues from the predatory crab Thalamita danae maintained on different diets, and byssal thread production of the mussels was studied. P. viridis produced the highest number as well as the thickest and longest byssal threads when they were exposed to crabs maintained on a diet of P. viridis as compared with those exposed to crabs maintained on a diet of the top shell Monodonta labio, the rock oyster Saccostrea cucullata, or crabs that were starved. For B. variabilis, results were similar, in that a diet containing B. variabilis elicited the greatest response as compared with other treatments. This indicates that the mussels were able to discriminate chemical cues released from predators maintained on different diets, and respond accordingly to the level of predation risk. By increasing the strength of byssal attachment as a defensive trait, the chance of being dislodged and consumed by crabs is reduced. As energy cost involved in the induction of an antipredatory response is considerable, this defensive trait seems to be an advantage to the mussels in enhancing efficiency. The short response time in byssal thread production allows the mussels to increase resistance against predation by crabs at the time when predation pressure is the highest in a tidal cycle.

  18. Comparative feedstock analysis in Setaria viridis L. as a model for C4 bioenergy grasses and Panicoid crop species

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    Carloalberto ePetti


    Full Text Available Second generation feedstocks for bioethanol will likely include a sizable proportion of perennial C4 grasses, principally in the Panicoideae clade. The Panicoideae contain agronomically important annual grasses including Zea mays L. (maize, Sorghum bicolor (L. Moench (sorghum, and Saccharum officinarum L. (sugar cane as well as promising second generation perennial feedstocks including Miscanthus x giganteus and Panicum virgatum L. (switchgrass. The underlying complexity of these polyploid grass genomes is a major limitation for their direct manipulation and thus driving a need for rapidly cycling comparative model. Setaria viridis (green millet is a rapid cycling C4 Panicoid grass with a relatively small and sequenced diploid genome and abundant seed production. Stable, transient and protoplast transformation technologies have also been developed for S. viridis making it a potentially excellent model for other C4 bioenergy grasses. Here, the lignocellulosic feedstock composition, cellulose biosynthesis inhibitor (CBI response and saccharification dynamics of S. viridis are compared with the annual s00orghum and maize and the perennial switchgrass bioenergy crops as a baseline study into the applicability for translational research. A genome-wide systematic investigation of the cellulose synthase-A (CesA genes was performed identifying eight candidate sequences. Two-developmental stages; a metabolically active young tissue and b metabolically plateaued (mature material are examined to compare biomass performance metrics.

  19. Drosophila molting neurohormone bursicon is a heterodimer and the natural agonist of the orphan receptor DLGR2

    DEFF Research Database (Denmark)

    Mendive, Fernando M; Van Loy, Tom; Claeysen, Sylvie;


    here Drosophila bioactive bursicon as a heterodimer made of two cystine knot polypeptides. This conclusion was reached in part from the unexpected observation that in the genome of the honey bee, the orthologs of the two Drosophila proteins are predicted to be fused in a single open reading frame...

  20. Photosynthetic performance of Setaria viridis to soil drought and rewatering alternations

    Institute of Scientific and Technical Information of China (English)


    The ability of psammophyte(a plant that grows in sand or sandy soil) to withstand and recover from severe droughts is crucial for desertification control and restoration of degraded vegetation in semi-arid sandy land in northern China.Responses of the photo-synthetic gas exchange and chlorophyll fluorescence of an annual(Setaria viridis) were measured through three cycles of soil drying and rewatering.Results showed that the net photosynthesis rate(Pn) decreased by 95 percent,91 percent,and 61 percent at end of three drought periods;the stomatal conductance(gs) decreased by 72 percent,73 percent,and 53 percent;the transpiration rate(Tr) decreased by 70 percent,69 percent,and 37 percent;and water-use efficiency(WUE) decreased by 83 percent,69 percent,and 38 percent.At the same time,the trapping probability with no dark adaptation(FV’/FM’) decreased by 70 percent,12 percent,and 10 percent,while the electron transport per cross-section(ET0’/CS’0) decreased by 80 percent,45 percent,and 13 percent.The intercellular CO2(Ci) increased by 1.77,1.02,and 0.66 times,and the dissipation per cross-section(DI0’/CS0’) increased by 98 percent,28 percent,and 22 percent.These results indicated that S.viridis was subjected to photoinhibition and some nonstomatal limitation of photosynthesis under drought.However,the above photosynthetic characteristics were restored to control values after three or four days of rewatering.The capability to recover from drought may contribute to the plant’s use of water as efficiently as possible.Furthermore,during the subsequent drought spells,suppression of Pn,gs,Tr,FV’/FM’,and ET0’/CS0’ decreased or slowed down following the drying and rewatering alternations,especially in the third drought spell.

  1. Detection of Cryptosporidium oocysts in green mussels (Perna viridis) from shell-fish markets of Thailand. (United States)

    Srisuphanunt, M; Wiwanitkit, Viroj; Saksirisampant, W; Karanis, P


    Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis), the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24) and Samut Prakan (n = 32) a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels' cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA) in 12.5% of the samples examined. The detection of Cryptosporidium oocysts in green mussels' population of Samut Prakan was higher (15.6%) than in Bangkok market (8.3%). These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans.

  2. Detection of Cryptosporidium oocysts in green mussels (Perna viridis from shell-fish markets of Thailand

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    Srisuphanunt M.


    Full Text Available Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis, the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24 and Samut Prakan (n = 32 a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels’ cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA in 12.5% of the samples examined. The detection of Cryptosporidium oocysts in green mussels’ population of Samut Prakan was higher (15.6% than in Bangkok market (8.3%. These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans.

  3. Ultraviolet nuptial colour determines fight success in male European green lizards (Lacerta viridis). (United States)

    Bajer, Katalin; Molnár, Orsolya; Török, János; Herczeg, Gábor


    Animal communication through colour signals is a central theme in sexual selection. Structural colours can be just as costly and honest signals as pigment-based colours. Ultraviolet (UV) is a structural colour that can be important both in intrasexual competition and mate choice. However, it is still unknown if a UV signal alone can determine the outcome of male-male fights. European green lizard (Lacerta viridis) males develop a nuptial throat coloration with a strong UV component. Among males differing only in their manipulated UV colour, females prefer males with higher UV. Here, we experimentally decreased the UV coloration of randomly chosen males from otherwise similar male pairs to test the hypothesis that a difference in UV colour alone can affect fight success during male-male competition. Our results fully supported the hypotheses: in almost 90 per cent of the contests the male with reduced UV lost the fight. Our results show that UV can be an important signal, affecting both female mate choice and determining male fight success.

  4. Uptake,Deuration and Subcellular Distribution of Cadmium in Various Tissues of Perna Viridis

    Institute of Scientific and Technical Information of China (English)

    M.S.YANG; S.T.CHIU; 等


    Green-lipped mussels(Perna viridis)were collected from a local mariculture site and placed in pre-cleaned sea water tanks containing 0,0.2,0.5and 1.3μg/ml CdCl2.The level of Cd in the gill,viscera and gonad was measured.The concentration of Cd in the 3 tissues increased linearly over 4 days' of exposure.The rate of uptake depends on the concentration of Cd in the water.In the 3 tissues studied,the maximum rate of uptake(Vmax)was highest in the gill(500μg/g dry weiht/day),followed by viscera(100μg/g dry weight/ day)and gonad(56.8μg/g dry weight/day).The majority of the Cd taken up was bound to a fraction of the heat-stable proteins similar to metallothioneins.The rate of Cd depuration from the tissues was poor.There was no change in Cd concentration over 8 days' depuration in clean water.

  5. Life History of the Camelthorn Gall Leafhopper, Scenergates viridis (Vilbaste (Hemiptera, Cicadellidae

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    Roman Rakitov


    Full Text Available The world’s only member of Hemiptera Auchenorrhyncha known to form true galls, the leafhopper Scenergates viridis (Vilbaste (Cicadellidae, transforms leaves of camelthorn (Alhagi maurorum Medikus, Fabaceae into pod-like chambers, up to 35 mm long, inside which individual leafhoppers develop, mate, and lay eggs. At the study site 40 km SE of Bukhara (Uzbekistan, two generations develop annually. First-instar nymphs cause young leaves to fold along the midrib. The subsequent development takes place inside the tightly closed growing gall, plugged at both ends with a mixture of leafhopper excrement, brochosomes, and crushed exuviae. These plugs act as mechanical barriers and sticky traps for intruders. The inner surface of the gall, lined with brochosomes and wax platelets, is hydrophobic. Adult males emerge from their galls and squeeze into female galls. Fertilized females insert an average of 146 eggs under the gall’s inner epidermis and remain inside, possibly protecting the brood, until they die. The walls of the galls containing eggs are approximately three times thicker than regular leaves. The galls are subject to predation by Gelechiidae caterpillars; the eggs of the leafhopper are parasitized by two species of Trichogrammatidae and one Mymaridae (Hymenoptera, and its larvae by one species of Pipunculidae (Diptera.

  6. The effect of Euglena viridis on immune response of rohu, Labeo rohita (Ham.). (United States)

    Das, Basanta Kumar; Pradhan, Jyotirmayee; Sahu, Swagatika


    The study evaluated the effect of dietary doses of Euglena viridis on the immune response and disease resistance of Labeo rohita fingerlings against infection with the bacterial pathogen Aeromonas hydrophila. L. rohita fingerlings were fed with diet containing 0 (Control), 0.1 g, 0.5 g, 1.0 g Euglena powder kg(-1) dry diet for 90 days. Biochemical (serum total protein, albumin, globulin, albumin:globulin ratio), haematological (WBC, RBC, haemoglobin content) and immunological (superoxide anion production, lysozyme, serum bactericidal activity) parameters of fish were examined after 30, 60 and 90 days of feeding. Fish were challenged with A. hydrophila 90 days post-feeding and mortalities were recorded over 10 days post-infection. The results demonstrate that fish fed with Euglena showed increased levels of superoxide anion production, lysozyme, serum bactericidal activity, serum protein and albumin (P Euglena kg(-1) dry diet showed the highest percentage survival (75%). These results indicate that Euglena stimulates the immunity and makes L. rohita more resistant to A. hydrophila infection.

  7. Phytolith analysis for differentiating between foxtail millet (Setaria italica and green foxtail (Setaria viridis.

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    Jianping Zhang

    Full Text Available Foxtail millet (Setaria italica is one of the oldest domesticated cereal crops in Eurasia, but identifying foxtail millets, especially in charred grains, and differentiating it from its wild ancestor, green foxtail (Setaria viridis, in the archaeobotanical remains, is still problematic. Phytolithic analysis provides a meaningful method for identifying this important crop. In this paper, the silicon structure patterns in the glumes, lemmas, and paleas from inflorescence bracts in 16 modern plants of foxtail millet and green foxtail from China and Europe are examined using light microscopy with phase-contrast and a microscopic interferometer. Our research shows that the silicon structure of ΩIII from upper lemmas and paleas in foxtail millet and green foxtail can be correspondingly divided into two groups. The size of ΩIII type phytolith of foxtail millet is bigger than that from green foxtail. Discriminant function analysis reveals that 78.4% of data on foxtail millet and 76.9% of data on green foxtail are correctly classified. This means certain morphotypes of phytoliths are relatively reliable tools for distinguishing foxtail millet from green foxtail. Our results also revealed that the husk phytolith morphologies of foxtail millets from China and Eastern Europe are markedly different from those from Western Europe. Our research gives a meaningful method of separating foxtail millet and green foxtail. The implications of these findings for understanding the history of foxtail millet domestication and cultivation in ancient civilizations are significant.

  8. Sequencing and Analysis of a Genomic Fragment Provide an Insight into the Dunaliella viridis Genomic Sequence

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ming SUN; Yuan-Ping TANG; Xiang-Zong MENG; Wen-Wen ZHANG; Shan LI; Zhi-Rui DENG; Zheng-Kai XU; Ren-Tao SONG


    Dunaliella is a genus of wall-less unicellular eukaryotic green alga. Its exceptional resistances to salt and various other stresses have made it an ideal model for stress tolerance study. However, very little is known about its genome and genomic sequences. In this study, we sequenced and analyzed a 29,268 bp genomic fragment from Dunaliella viridis. The fragment showed low sequence homology to the GenBank database. At the nucleotide level, only a segment with significant sequence homology to 18S rRNA was found. The fragment contained six putative genes, but only one gene showed significant homology at the protein level to GenBank database. The average GC content of this sequence was 51.1%, which was much lower than that of close related green algae Chlamydomonas (65.7%). Significant segmental duplications were found within this fragment. The duplicated sequences accounted for about 35.7% of the entire region. Large amounts of simple sequence repeats (microsatellites) were found, with strong bias towards (AC)n type (76%). Analysis of other Dunaliella genomic sequences in the GenBank database (total 25,749 bp) was in agreement with these findings. These sequence features made it difficult to sequence Dunaliella genomic sequences. Further investigation should be made to reveal the biological significance of these unique sequence features.

  9. Mathematical modeling of sub-cellular asymmetry of fat-dachsous heterodimer for generation of planar cell polarity.

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    Mohit Kumar Jolly

    Full Text Available Planar Cell Polarity (PCP is an evolutionarily conserved characteristic of animal tissues marked by coordinated polarization of cells or structures in the plane of a tissue. In insect wing epithelium, for instance, PCP is characterized by en masse orientation of hairs orthogonal to its apical-basal axis and pointing along the proximal-distal axis of the organ. Directional cue for PCP has been proposed to be generated by complex sets of interactions amongst three proteins - Fat (Ft, Dachsous (Ds and Four-jointed (Fj. Ft and Ds are two atypical cadherins, which are phosphorylated by Fj, a Golgi kinase. Ft and Ds from adjacent cells bind heterophilically via their tandem cadherin repeats, and their binding affinities are regulated by Fj. Further, in the wing epithelium, sub-cellular levels of Ft-Ds heterodimers are seen to be elevated at the distal edges of individual cells, prefiguring their PCP. Mechanisms generating this sub-cellular asymmetry of Ft-Ds heterodimer in proximal and distal edges of cells, however, have not been resolved yet. Using a mathematical modeling approach, here we provide a framework for generation of this sub-cellular asymmetry of Ft-Ds heterodimer. First, we explain how the known interactions within Ft-Ds-Fj system translate into sub-cellular asymmetry of Ft-Ds heterodimer. Second, we show that this asymmetric localization of Ft-Ds heterodimer is lost when tissue-level gradient of Fj is flattened, or when phosphorylation of Ft by Fj is abolished, but not when tissue-level gradient of Ds is flattened or when phosphorylation of Ds is abrogated. Finally, we show that distal enrichment of Ds also amplifies Ft-Ds asymmetry. These observations reveal that gradient of Fj expression, phosphorylation of Ft by Fj and sub-cellular distal accumulation of Ds are three critical elements required for generating sub-cellular asymmetry of Ft-Ds heterodimer. Our model integrates the known experimental data and presents testable predictions

  10. Inter-population thermal variability and physiological response in the intertidal fish Scartichthys viridis (Blenniidae Variabilidad térmica intrapoblacional y respuesta fisiológica en el pez intermareal Scartichthys viridis (Blenniidae

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    Full Text Available Determining habitat conditions that generate individual physiological variability represents key basic knowledge to understand the direction of animal's responses to habitat change. The coastal fish Scartichthys viridis inhabits low intertidal pools along the Chilean coast. Because seawater in the low intertidal is renewed during every tidal cycle, this zone is characterized by a low thermal variation and abundant food within and between localities. We evaluated whether seawater thermal conditions and food availability of low intertidal pools registered in three localities of Chilean coast are sufficient to generate physiological and energetic differences in individuals of S. viridis captured from three geographic separate populations spanning approximately 1,200 km. Southern fishes acclimatized to 25 °C showed higher metabolic rates than those from other localities and thermal treatments. On the other hand, southern fishes in natural conditions showed higher condition factor than northern fishes. This evidence is sufficient to indicate that slight latitudinal differences in tidepool seawater temperature associated to differential food availability induced an energetic constraint in this species. Moreover, southern population of S. viridis may suffer important effects on energetic allocation if seawater temperature increases slightly, with repercussions on its geographic distribution in southern Pacific OceanDeterminar las condiciones del ambiente que generan variabilidad fisiológica, representa un conocimiento básico para comprender el sentido de la respuesta de los animales a los cambios en su habitat. El pez costero Scartichthys viridis habita las pozas bajas del intermareal a lo largo de la costa chilena. Debido a que el agua de mar se renueva en cada ciclo de marea en las pozas bajas, esta zona está caracterizada por una baja variación térmica y abundante alimento entre localidades. Nosotros evaluamos si las condiciones térmicas y la

  11. Rifampicin does not significantly affect the expression of Small heterodimer partner (SHP in primary human hepatocytes

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    Petr ePavek


    Full Text Available The small/short heterodimer partner (SHP, NR0B2 is a nuclear receptor corepressor lacking a DNA binding domain. SHP is induced by bile acid-activated farnesoid X receptor (FXR resulting in CYP7A1 gene suppression. In contrast, Pregnane X receptor (PXR activation by its ligands was recently suggested to inhibit SHP gene transactivation to maximize the induction of PXR target genes. However, there are also conflicting reports in literature whether PXR or rodent Pxr activation down-regulates SHP/Shp expression. Moreover, the PXR-mediated regulation of the SHP gene has been studied only at the SHP mRNA and transactivation (gene reporter assay levels.In this study, we studied the effect of rifampicin, a prototype PXR ligand, on SHP mRNA and protein expression in three primary human hepatocyte cultures.We found that SHP mRNA is not systematically down-regulated in hepatocyte in culture after 24 h treatment with rifampicin. Consistently, we did not observe down-regulation of SHP protein in primary human hepatocytes after 24 and 48 h of incubation with rifampicin.We can conclude that although we observed slight down-regulation of SHP mRNA and protein in several hepatocyte preparations, the phenomenon is unlikely critical for PXR-mediated induction of its target genes.

  12. MutLα heterodimers modify the molecular phenotype of Friedreich ataxia.

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    Vahid Ezzatizadeh

    Full Text Available BACKGROUND: Friedreich ataxia (FRDA, the most common autosomal recessive ataxia disorder, is caused by a dynamic GAA repeat expansion mutation within intron 1 of FXN gene, resulting in down-regulation of frataxin expression. Studies of cell and mouse models have revealed a role for the mismatch repair (MMR MutS-heterodimer complexes and the PMS2 component of the MutLα complex in the dynamics of intergenerational and somatic GAA repeat expansions: MSH2, MSH3 and MSH6 promote GAA repeat expansions, while PMS2 inhibits GAA repeat expansions. METHODOLOGY/PRINCIPAL FINDINGS: To determine the potential role of the other component of the MutLα complex, MLH1, in GAA repeat instability in FRDA, we have analyzed intergenerational and somatic GAA repeat expansions from FXN transgenic mice that have been crossed with Mlh1 deficient mice. We find that loss of Mlh1 activity reduces both intergenerational and somatic GAA repeat expansions. However, we also find that loss of either Mlh1 or Pms2 reduces FXN transcription, suggesting different mechanisms of action for Mlh1 and Pms2 on GAA repeat expansion dynamics and regulation of FXN transcription. CONCLUSIONS/SIGNIFICANCE: Both MutLα components, PMS2 and MLH1, have now been shown to modify the molecular phenotype of FRDA. We propose that upregulation of MLH1 or PMS2 could be potential FRDA therapeutic approaches to increase FXN transcription.

  13. DNA end binding activity and Ku70/80 heterodimer expression in human colorectal tumor

    Institute of Scientific and Technical Information of China (English)

    Paola Mazzarelli; Carolina Gravina; Marco Caricato; Maria Luana Poeta; Monica Rinaldi; Sergio Valeri; Roberto Coppola; Vito Michele Fazio; Paola Parrella; Davide Seripa; Emanuela Signori; Giuseppe Perrone; Carla Rabitti; Domenico Borzomati; Armando Gabbrielli; Maria Giovanna Matera


    AIM: To determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis.METHODS: The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis.RESULTS: A statistically significant difference was found in both adenomas and carcinomas as compared to matched normal colonic mucosa (P<0.00). However,changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86nuclear expression, as determined by Western blot and immunohistochemical analyses (P<0.001). Cytoplasmic protein expression was found in pathological samples,but not in normal tissues either from tumor patients or from healthy subjects.CONCLUSION: Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.

  14. Nuclear Receptor Small Heterodimer Partner in Apoptosis Signaling and Liver Cancer

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    Zhang, Yuxia; Wang, Li, E-mail: [Departments of Medicine and Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84132 (United States)


    Small heterodimer partner (SHP, NR0B2) is a unique orphan nuclear receptor that contains the dimerization and a putative ligand-binding domain, but lacks the conserved DNA binding domain. SHP exerts its physiological function as an inhibitor of gene transcription through physical interaction with multiple nuclear receptors and transcriptional factors. SHP is a critical transcriptional regulator affecting diverse biological functions, including bile acid, cholesterol and lipid metabolism, glucose and energy homeostasis, and reproductive biology. Recently, we and others have demonstrated that SHP is an epigenetically regulated transcriptional repressor that suppresses the development of liver cancer. In this review, we summarize recent major findings regarding the role of SHP in cell proliferation, apoptosis, and DNA methylation, and discuss recent progress in understanding the function of SHP as a tumor suppressor in the development of liver cancer. Future study will be focused on identifying SHP associated novel prooncogenes and anti-oncogenes in liver cancer progression and applying the knowledge gained on SHP in liver cancer prevention, diagnosis and treatment.

  15. Yeast surface display of a noncovalent MHC class II heterodimer complexed with antigenic peptide. (United States)

    Boder, Eric T; Bill, Jerome R; Nields, Andrew W; Marrack, Philippa C; Kappler, John W


    Microbial protein display technologies have enabled directed molecular evolution of binding and stability properties in numerous protein systems. In particular, dramatic improvements to antibody binding affinity and kinetics have been accomplished using these tools in recent years. Examples of successful application of display technologies to other immunological proteins have been limited to date. Herein, we describe the expression of human class II major histocompatibility complex allele (MHCII) HLA-DR4 on the surface of Saccharomyces cerevisiae as a noncovalently associated heterodimer. The yeast-displayed MHCII is fully native as assessed by binding of conformationally specific monoclonal antibodies; failure of antibodies specific for empty HLA-DR4 to bind yeast-displayed protein indicates antigenic peptide is bound. This report represents the first example of a noncovalent protein dimer displayed on yeast and of successful display of wild-type MHCII. Results further point to the potential for using yeast surface display for engineering and analyzing the antigen binding properties of MHCII.

  16. Mechanism of Interspecific Competition between Pavlova viridis and Tetraselmis tetrethele%绿色巴夫藻和四列藻种间竞争机制研究

    Institute of Scientific and Technical Information of China (English)

    郭羽丰; 段舜山; 陈洁; 张亚楠


    Experiments of co-culture with Pavlova viridis and Tetraselmis tetrethele were carried out. Results showed a transparent phenomenon of interspecific competition between them. The competition was identified as an exploitation type through analysis. In the co-culture, both the growth rate (r) and the carrying capacity (K) of two species were affected, with a greater influence on P. viridis than on T. tetrethele, according to the comparision with those from the pure culture of two species. Each of interspecific competitive parameters of one species to the other was calculated, and the results showed that T. tetrethele possessed a more interspecific competitive capacity. Meanwhile, under the co-culture condition, both of the carrying capacity of two species were closely related to their respective inoculation density. The growth rate of P. viridis was in a positive proportion to its inoculation density, while a negative one existed in T. tetrethele.

  17. Spatiotemporal variations in metal accumulation, RNA/DNA ratio and energy reserve in Perna viridis transplanted along a marine pollution gradient in Hong Kong. (United States)

    Yeung, Jamius W Y; Zhou, Guang-Jie; Leung, Kenneth M Y


    We examined spatiotemporal variations of metal levels and three growth related biomarkers, i.e., RNA/DNA ratio (RD), total energy reserve (Et) and condition index (CI), in green-lipped mussels Perna viridis transplanted into five locations along a pollution gradient in the marine environment of Hong Kong over 120days of deployment. There were significant differences in metal levels and biomarker responses among the five sites and six time points. Mussels in two clean sites displayed better CI and significantly lower levels of Ag, Cu, Pb and Zn in their tissues than the other sites. Temporal patterns of RD in P. viridis were found to be site-specific. Across all sites, Et decreased in P. viridis over the deployment period, though the rate of decrease varied significantly among the sites. Therefore, temporal variation of biomarkers should be taken to consideration in mussel-watch programs because such information can help discriminate pollution-induced change from natural variation.

  18. Fluorescence Resonance Energy Transfer Imaging Reveals that Chemokine-Binding Modulates Heterodimers of CXCR4 and CCR5 Receptors



    BACKGROUND: Dimerization has emerged as an important feature of chemokine G-protein-coupled receptors. CXCR4 and CCR5 regulate leukocyte chemotaxis and also serve as a co-receptor for HIV entry. Both receptors are recruited to the immunological synapse during T-cell activation. However, it is not clear whether they form heterodimers and whether ligand binding modulates the dimer formation. METHODOLOGY/PRINCIPAL FINDINGS: Using a sensitive Fluorescence Resonance Energy Transfer (FRET) imaging ...

  19. Multiple allelic forms of acetohydroxyacid synthase are responsible for herbicide resistance in Setaria viridis. (United States)

    Laplante, Julie; Rajcan, Istvan; Tardif, François J


    In weed species, resistance to herbicides inhibiting acetohydroxyacid synthase (AHAS) is often conferred by genetic mutations at one of six codons in the AHAS gene. These mutations provide plants with various levels of resistance to different chemical classes of AHAS inhibitors. Five green foxtail [Setaria viridis (L.) Beauv.] populations were reported in Ontario with potential resistance to the AHAS-inhibiting herbicide imazethapyr. The objectives of this study were to confirm resistance, establish the resistance spectrum for each of the five populations, and determine its genetic basis. Dose response curves were generated for whole plant growth and enzyme activity, and the AHAS gene was sequenced. Resistance was confirmed by determining the resistance factor to imazethapyr in the five resistant green foxtail populations for whole plant dose response experiments (21- to 182-fold) and enzyme assays (15- to 260-fold). All five imazethapyr-resistant populations showed cross-resistance to nicosulfuron and flucarbazone while only three populations had cross-resistance to pyrithiobac. Sequence analyses revealed single base-pair mutations in the resistant populations of green foxtail. These mutations were coded for Thr, Asn, or Ile substitution at Ser(653). In addition, a new mutation was found in one population that coded for an Asp substitution at Gly(654). There is an agreement between the spectra of resistance observed and the type of resistance known to be conferred by these substitutions. Moreover, it indicates that, under similar selection pressure (imazethapyr), a variety of mutations can be selected for different populations, making the resistance pattern difficult to predict from herbicide exposure history.

  20. Behavioural and neurotoxic effects of ayahuasca infusion (Banisteriopsis caapi and Psychotria viridis) in female Wistar rat. (United States)

    Pic-Taylor, Aline; da Motta, Luciana Gueiros; de Morais, Juliana Alves; Junior, Willian Melo; Santos, Alana de Fátima Andrade; Campos, Leandro Ambrósio; Mortari, Marcia Renata; von Zuben, Marcus Vinicius; Caldas, Eloisa Dutra


    Ayahuasca, a psychoactive beverage used by indigenous and religious groups, is generally prepared by the coction of Psychotria viridis and Banisteriopsis caapi plants containing N,N-dimethyltryptamine (DMT) and β-carboline alkaloids, respectively. To investigate the acute toxicity of ayahuasca, the infusion was administered by gavage to female Wistar rats at doses of 30X and 50X the dose taken during a religious ritual, and the animals observed for 14 days. Behavioural functions were investigated one hour after dosing at 15X and 30X using the open field, elevated plus maze, and forced swimming tests. Neuronal activation (c-fos marked neurons) and toxicity (Fluoro-Jade B and Nissl/Cresyl staining) were investigated in the dorsal raphe nuclei (DRN), amygdaloid nucleus, and hippocampal formation brain areas of rats treated with a 30X ayahuasca dose. The actual lethal oral dose in female Wistar rats could not be determined in this study, but was shown to be higher than the 50X (which corresponds to 15.1mg/kg bw DMT). The ayahuasca and fluoxetine treated groups showed a significant decrease in locomotion in the open field and elevated plus-maze tests compared to controls. In the forced swimming test, ayahuasca treated animals swam more than controls, a behaviour that was not significant in the fluoxetine group. Treated animals showed higher neuronal activation in all brain areas involved in serotoninergic neurotransmission. Although this led to some brain injury, no permanent damage was detected. These results suggest that ayahuasca has antidepressant properties in Wistar female at high doses, an effect that should be further investigated.

  1. Molecular insight of isotypes specific β-tubulin interaction of tubulin heterodimer with noscapinoids (United States)

    Santoshi, Seneha; Naik, Pradeep K.


    Noscapine and its derivatives bind stoichiometrically to tubulin, alter its dynamic instability and thus effectively inhibit the cellular proliferation of a wide variety of cancer cells including many drug-resistant variants. The tubulin molecule is composed of α- and β-tubulin, which exist as various isotypes whose distribution and drug-binding properties are significantly different. Although the noscapinoids bind to a site overlapping with colchicine, their interaction is more biased towards β-tubulin. In fact, their precise interaction and binding affinity with specific isotypes of β-tubulin in the αβ-heterodimer has never been addressed. In this study, the binding affinity of a panel of noscapinoids with each type of tubulin was investigated computationally. We found that the binding score of a specific noscapinoid with each type of tubulin isotype is different. Specifically, amino-noscapine has the highest binding score of -6.4, -7.2, -7.4 and -7.3 kcal/mol with αβI, αβII, αβIII and αβIV isotypes, respectively. Similarly 10 showed higher binding affinity of -6.8 kcal/mol with αβV, whereas 8 had the highest binding affinity of -7.2, -7.1 and -7.2 kcal/mol, respectively with αβVI, αβVII and αβVIII isotypes. More importantly, both amino-noscapine and its clinical derivative, bromo-noscapine have the highest binding affinity of -46.2 and -38.1 kcal/mol against αβIII (overexpression of αβIII has been associated with resistance to a wide range of chemotherapeutic drugs for several human malignancies) as measured using MM-PBSA. Knowledge of the isotype specificity of the noscapinoids may allow for development of novel therapeutic agents based on this class of drugs.

  2. Small heterodimer partner overexpression partially protects against liver tumor development in farnesoid X receptor knockout mice

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    Li, Guodong [Department of Surgical Oncology, Cancer Treatment Center, The Fourth Affiliated Hospital of Harbin Medical University, Harbin (China); Kong, Bo [Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Zhu, Yan [Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing (China); Zhan, Le [Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Williams, Jessica A. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Tawfik, Ossama [Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Kassel, Karen M. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Luyendyk, James P. [Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI (United States); Wang, Li [Department of Medicine, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT (United States); Guo, Grace L., E-mail: [Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ (United States)


    Farnesoid X receptor (FXR, Nr1h4) and small heterodimer partner (SHP, Nr0b2) are nuclear receptors that are critical to liver homeostasis. Induction of SHP serves as a major mechanism of FXR in suppressing gene expression. Both FXR{sup −/−} and SHP{sup −/−} mice develop spontaneous hepatocellular carcinoma (HCC). SHP is one of the most strongly induced genes by FXR in the liver and is a tumor suppressor, therefore, we hypothesized that deficiency of SHP contributes to HCC development in the livers of FXR{sup −/−} mice and therefore, increased SHP expression in FXR{sup −/−} mice reduces liver tumorigenesis. To test this hypothesis, we generated FXR{sup −/−} mice with overexpression of SHP in hepatocytes (FXR{sup −/−}/SHP{sup Tg}) and determined the contribution of SHP in HCC development in FXR{sup −/−} mice. Hepatocyte-specific SHP overexpression did not affect liver tumor incidence or size in FXR{sup −/−} mice. However, SHP overexpression led to a lower grade of dysplasia, reduced indicator cell proliferation and increased apoptosis. All tumor-bearing mice had increased serum bile acid levels and IL-6 levels, which was associated with activation of hepatic STAT3. In conclusion, SHP partially protects FXR{sup −/−} mice from HCC formation by reducing tumor malignancy. However, disrupted bile acid homeostasis by FXR deficiency leads to inflammation and injury, which ultimately results in uncontrolled cell proliferation and tumorigenesis in the liver. - Highlights: • SHP does not prevent HCC incidence nor size in FXR KO mice but reduces malignancy. • Increased SHP promotes apoptosis. • Bile acids and inflammation maybe critical for HCC formation with FXR deficiency.

  3. The solute specificity profiles of nucleobase cation symporter 1 (NCS1) from Zea mays and Setaria viridis illustrate functional flexibility. (United States)

    Rapp, Micah; Schein, Jessica; Hunt, Kevin A; Nalam, Vamsi; Mourad, George S; Schultes, Neil P


    The solute specificity profiles (transport and binding) for the nucleobase cation symporter 1 (NCS1) proteins, from the closely related C4 grasses Zea mays and Setaria viridis, differ from that of Arabidopsis thaliana and Chlamydomonas reinhardtii NCS1. Solute specificity profiles for NCS1 from Z. mays (ZmNCS1) and S. viridis (SvNCS1) were determined through heterologous complementation studies in NCS1-deficient Saccharomyces cerevisiae strains. The four Viridiplantae NCS1 proteins transport the purines adenine and guanine, but unlike the dicot and algal NCS1, grass NCS1 proteins fail to transport the pyrimidine uracil. Despite the high level of amino acid sequence similarity, ZmNCS1 and SvNCS1 display distinct solute transport and recognition profiles. SvNCS1 transports adenine, guanine, hypoxanthine, cytosine, and allantoin and competitively binds xanthine and uric acid. ZmNCS1 transports adenine, guanine, and cytosine and competitively binds, 5-fluorocytosine, hypoxanthine, xanthine, and uric acid. The differences in grass NCS1 profiles are due to a limited number of amino acid alterations. These amino acid residues do not correspond to amino acids essential for overall solute and cation binding or solute transport, as previously identified in bacterial and fungal NCS1, but rather may represent residues involved in subtle solute discrimination. The data presented here reveal that within Viridiplantae, NCS1 proteins transport a broad range of nucleobase compounds and that the solute specificity profile varies with species.

  4. Effects of reduced carbonic anhydrase activity on CO2 assimilation rates in Setaria viridis: a transgenic analysis. (United States)

    Osborn, Hannah L; Alonso-Cantabrana, Hugo; Sharwood, Robert E; Covshoff, Sarah; Evans, John R; Furbank, Robert T; von Caemmerer, Susanne


    In C4 species, the major β-carbonic anhydrase (β-CA) localized in the mesophyll cytosol catalyses the hydration of CO2 to HCO3(-), which phosphoenolpyruvate carboxylase uses in the first step of C4 photosynthesis. To address the role of CA in C4 photosynthesis, we generated transgenic Setaria viridis depleted in β-CA. Independent lines were identified with as little as 13% of wild-type CA. No photosynthetic defect was observed in the transformed lines at ambient CO2 partial pressure (pCO2). At low pCO2, a strong correlation between CO2 assimilation rates and CA hydration rates was observed. C(18)O(16)O isotope discrimination was used to estimate the mesophyll conductance to CO2 diffusion from the intercellular air space to the mesophyll cytosol (gm) in control plants, which allowed us to calculate CA activities in the mesophyll cytosol (Cm). This revealed a strong relationship between the initial slope of the response of the CO2 assimilation rate to cytosolic pCO2 (ACm) and cytosolic CA activity. However, the relationship between the initial slope of the response of CO2 assimilation to intercellular pCO2 (ACi) and cytosolic CA activity was curvilinear. This indicated that in S. viridis, mesophyll conductance may be a contributing limiting factor alongside CA activity to CO2 assimilation rates at low pCO2.

  5. Influence of rearing water temperature on inducedgonadal development and spawning behaviour of tropical green mussel,Perna viridis

    Institute of Scientific and Technical Information of China (English)

    Parathattil Rathan Sreedevi; Venkatachalam Uthayakumar; Rajarajeswaran Jayakumar; Venkatachalam Ramasubramanian


    Objective:To standardize the technique of induced breeding and spawning of green mussel Perna viridis(P. viridis), in captivity.Methods:InExperiment-A, the temperature was increased at a rate of2℃/5 days interval.InExperiment-B, a rise of3℃/5 days was practiced, whereas inExperimentC andD, respectively4 and5℃ was increased in5 days interval. The temperature was maintained constant at20℃ in theControl.Results:The increase in temperature showed a progressive effect on the gonadal development of mussels.The gonads ripped at30 to32℃ in all the experimental tanks, irrespective of the difference in temperature hike.Complete spawning inP. viridiswas achieved by gradually raising the temperature from 20 to35℃ at a rate of3 or4℃/5 days.Conclusion:According to the present study temperature induced spawning method is very simple and cost effective and can accelerate the production of mussel seeds in hatchery units and further stock improvement through genetic manipulation.

  6. Heterodimers formed through a partial anionic exchange process: scanning tunneling spectroscopy to monitor bands across the junction vis-à-vis photoinduced charge separation (United States)

    Bera, Abhijit; Saha, Sudip K.; Pal, Amlan J.


    We report controlled formation of heterodimers and their charge separation properties. CdS|CdTe heterodimers were formed through an anionic exchange process of CdS nanostructures. With control over the duration of the anionic exchange process, bulk|dot, bulk|bulk, and then dot|bulk phases of the semiconductors could be observed to have formed. A mapping of density of states as derived from scanning tunneling spectroscopy (STS) brought out conduction and valence band-edges along the nanostructures and heterodimers. The CdS|CdTe heterodimers evidenced a type-II band-alignment between the semiconductors along with the formation of a depletion region at the interface. The width (of the depletion region) and the energy-offset at the interface depended on the size of the semiconductors. We report that the width that is instrumental for photoinduced charge separation in the heterodimers has a direct correlation with the performance of hybrid bulk-heterojunction solar cells based on the nanostructures in a polymer matrix.We report controlled formation of heterodimers and their charge separation properties. CdS|CdTe heterodimers were formed through an anionic exchange process of CdS nanostructures. With control over the duration of the anionic exchange process, bulk|dot, bulk|bulk, and then dot|bulk phases of the semiconductors could be observed to have formed. A mapping of density of states as derived from scanning tunneling spectroscopy (STS) brought out conduction and valence band-edges along the nanostructures and heterodimers. The CdS|CdTe heterodimers evidenced a type-II band-alignment between the semiconductors along with the formation of a depletion region at the interface. The width (of the depletion region) and the energy-offset at the interface depended on the size of the semiconductors. We report that the width that is instrumental for photoinduced charge separation in the heterodimers has a direct correlation with the performance of hybrid bulk

  7. Sédentarité, déplacements et répartition des individus dans une population de Lacerta viridis (Laurenti, 1768) (Lacertilia, Lacertidae)

    NARCIS (Netherlands)

    Girons, Saint H.; Bradshaw, S.D.


    A mark-and-recapture study was undertaken in August 1983, May and September 1987, and May 1988 of a small discrete population of Lacerta viridis occupying an area of 260 x 11—25 m, along the length of a canal in western France. A total of 21 recaptures, over periods of time varying from four months

  8. Terpenoids, flavonoids and caffeic acid derivatives from Salvia viridis L. cvar. Blue Jeans. (United States)

    Rungsimakan, Supattra; Rowan, Michael G


    Three diterpenoids, 1-oxomicrostegiol (1), viroxocin (2), viridoquinone (3), were isolated from the roots of Salvia viridis L. cvar. Blue Jeans. Five known diterpenoids, microstegiol (4), 7α-acetoxy-14-hydroxy-8,13-abietadiene-11,12-dione (5; 7-O-acetylhorminone tautomer), 7α,14-dihydroxy-8,13-abietadiene-11,12-dione (6; horminone tautomer), ferruginol and salvinolonyl 12-methyl ether (7) were also found in the roots together with 1-docosyl ferulate (8), and a mixture of 2-(4'-alkoxyphenyl) ethyl alkanoates (9). Two lupane triterpenoids, 2α-acetoxy-lup-20(29)-en-3β-ol (10), and 3β-acetoxy-lup-20(29)-en-2α-ol (11) were found in the aerial parts together with known compounds, lup-20(29)-ene-2α,3β-diol (12), ursolic acid, oleanolic acid, β-sitosterol and β-sitosterol glucoside. A known phenylpropanoid, trans-verbascoside (or acteoside; 13), was the main constituent in the polar fraction of the aerial part, and it is now reported in the genus Salvia for the first time. Other polyphenolic compounds were cis-verbascoside (14), leucosceptoside A (15), martynoside (16), caffeic acid, 6-O-caffeoyl-glucose (18), rosmarinic acid, salidroside, luteolin-7-O-α-rhamnopyranosyl-(1→6)-β-galactopyranoside, luteolin-7-O-β-galactopyranoside, luteolin-7-O-α-rhamnopyranosyl-(1→6)-β-glucopyranoside, luteolin-7-O-β-glucopyranoside, and apigenin-7-O-β-glucopyranoside. The structures were determined by 1D-, 2D-NMR and HR-ESI-MS techniques. Compounds 6, 10, ferruginol, ursolic acid and oleanolic acid exhibited antibacterial activity against Enterococcus faecalis (ATCC 775) with MIC 50 μM, 25 μM, 50 μM, 12.5 μM, 12.5 μM respectively. Ferruginol, ursolic acid and oleanolic acid were also active against Staphylococcus aureus (ATCC 6571), and Bacillus cereus (ATCC 2599) with MIC 12.5-50 μM. 4 was also active against S.aureus (ATCC 6571) with MIC 50 μM. These values are consistent with previous studies on the antimicrobial activity of Salvia diterpenoids.

  9. Pheromones exert top-down effects on visual recognition in the jumping spider Lyssomanes viridis. (United States)

    Tedore, Cynthia; Johnsen, Sönke


    In diverse and productive habitats, predaceous arthropods are expected to frequently encounter dangerous conspecifics and heterospecifics. This should make quick and accurate discriminations between species and sexes adaptive. By simultaneously sampling both visual cues and pheromones, and by utilizing stringent species- and sex-specific visual recognition templates, an individual should be able to increase both its speed and accuracy in making such discriminations. We tested for the use and stringency of visual recognition templates in the jumping spider Lyssomanes viridis by presenting males with animated images of conspecifics, heterospecifics and composite images that combined the facial coloration and morphology of one sex or species with the leg coloration of another. Males' courtship versus threat displays indicated whether a stimulus was perceived as a potential mate or a threat. By comparing males' visual inspection times of, and display types towards, the various images in the presence versus absence of female pheromones, we were able to deduce whether males tend to inspect a subset of the color pattern and morphological features that make up their conspecific recognition templates (i.e. those on just the face or just the legs), or all features, and whether this changes in the presence of pheromones. We found that the male recognition template for conspecific female was surprisingly coarse, whereas the recognition template for conspecific male, and especially the male face, was more specific. Pheromones hastened the recognition of images with coloration and morphology closely matching those of conspecifics, presumably by activating conspecific visual recognition templates. When males were presented with an image that was, overall, a poor match to a conspecific female, but that contained a subset of female or female-like features, female pheromones usually did not hasten recognition, but did increase the likelihood that the image would be identified as a

  10. Structural basis for a Munc13-1 homodimer to Munc13-1/RIM heterodimer switch.

    Directory of Open Access Journals (Sweden)

    Jun Lu


    Full Text Available C(2 domains are well characterized as Ca(2+/phospholipid-binding modules, but little is known about how they mediate protein-protein interactions. In neurons, a Munc13-1 C(2A-domain/RIM zinc-finger domain (ZF heterodimer couples synaptic vesicle priming to presynaptic plasticity. We now show that the Munc13-1 C(2A domain homodimerizes, and that homodimerization competes with Munc13-1/RIM heterodimerization. X-ray diffraction studies guided by nuclear magnetic resonance (NMR experiments reveal the crystal structures of the Munc13-1 C(2A-domain homodimer and the Munc13-1 C(2A-domain/RIM ZF heterodimer at 1.44 A and 1.78 A resolution, respectively. The C(2A domain adopts a beta-sandwich structure with a four-stranded concave side that mediates homodimerization, leading to the formation of an eight-stranded beta-barrel. In contrast, heterodimerization involves the bottom tip of the C(2A-domain beta-sandwich and a C-terminal alpha-helical extension, which wrap around the RIM ZF domain. Our results describe the structural basis for a Munc13-1 homodimer-Munc13-1/RIM heterodimer switch that may be crucial for vesicle priming and presynaptic plasticity, uncovering at the same time an unexpected versatility of C(2 domains as protein-protein interaction modules, and illustrating the power of combining NMR spectroscopy and X-ray crystallography to study protein complexes.

  11. Self-assembly of Hydrazide-based Heterodimers Driven by Hydrogen Bonding and Donor-Acceptor Interaction

    Institute of Scientific and Technical Information of China (English)

    FENG,Dai-Jun; WANG,Peng; LI,Xiao-Qiang; LI,Zhan-Ting


    A new series of hydrogen bonding-driven heterodimers have been self-assembled in chloroform from hydrazide-based monomers. Additional intermolecular donor-acceptor interaction between the electron-rich bis(p-phenylene)-34-crown-10 unit and the electron-deficient naphthalene diimide unit has been utilized to increase the stability of the dimmers, and pronounced cooperativity of the two discrete non-covalent forces to stabilize the dimer has been revealed by the quantitative 1H (2D) NMR and UV-Vis experiments.

  12. Spermatogenesis of the green-lipped mussel Perna viridis with dual patterns of acrosome and tail development in spermatids (United States)

    Reunov, A. A.; Au, D. W. T.; Wu, R. S. S.


    Spermatogenesis in the mussel Perna viridis was studied by electron microscopy. Results demonstrated that cytological development in spermatogonia and spermatocytes was similar to that previously described in other Mytilidae. Acrosome formation began with the arising of proacrosomal vesicles in spermatogonia. The abundance of proacrosomal vesicles increased in spermatocytes, which were flagellated. However, during spermiogenesis, dual patterns of acrosome development as well as flagellum development could be found among spermatids in a male gonad. The two lines of acrosome formation in spermatids ultimately gave rise to morphologically similar acrosomes. The two lines of flagellum development in spermatids resulted in the formation of sperm cells with either a typically posteriorly directed tail or an anteriorly directed tail.

  13. Qualitative Assessment and Management of Microplastics in Asian Green Mussels (Perna viridis Cultured in Bacoor Bay, Cavite, Phillipines

    Directory of Open Access Journals (Sweden)

    Cristian Ryan Argamino


    Full Text Available Microplastics (> 5 mm have gained popularity in research and the public eye in recent years. This is due to the fact that they contain persistent organic pollutants (POPs which pose potential risks to the environment and human health. Bivalves, which are filter feeders, are considered to be good indicators of marine pollution. In this preliminary study, Asian green mussel (Perna viridis, an example of edible bivalve, cultured in Bacoor Bay, Cavite, Philippines was subjected to qualitative analysis to determine the presence of microplastics. Through microscopic analysis, microplastics were found present in the acid-digested mussel soft tissue. A management program is suggested for policy makers and stakeholders to reduce the negative impact of microplastic pollution to both humans and the marine environment.

  14. Partially Purified Extracts of Sea Anemone Anemonia viridis Affect the Growth and Viability of Selected Tumour Cell Lines (United States)

    Bulati, Matteo; Longo, Alessandra; Vlah, Sara; Bennici, Carmelo; Bonura, Angela; Tagliavia, Marcello; Mazzola, Salvatore


    In the last few years, marine species have been investigated for the presence of natural products with anticancer activity. Using reversed phase chromatography, low molecular weight proteins were fractionated from the sea anemone Anemonia viridis. Four different fractions were evaluated for their cytotoxic activity by means of erythrocyte haemolysis test, MTS, and LDH assays. Finally, the antiproliferative activities of three of these fractions were studied on PC3, PLC/PRF/5, and A375 human cancer cell lines. Our analysis revealed that the four fractions showed different protein contents and diverse patterns of activity towards human PBMC and cancer cell lines. Interestingly, fractions III and IV exerted cytotoxic effects on human cells. Conversely, fractions I and II displayed very low toxic effects associated with antiproliferative activities on cancer cell lines. PMID:27725939

  15. Instabilities in the optical response of a semiconductor quantum dot—metal nanoparticle heterodimer: self-oscillations and chaos (United States)

    Nugroho, Bintoro S.; Iskandar, Alexander A.; Malyshev, Victor A.; Knoester, Jasper


    We theoretically investigate the nonlinear optical response of a heterodimer comprising a semiconductor quantum dot strongly coupled to a metal nanoparticle. The quantum dot is considered as a three-level ladder system with ground, one-exciton, and bi-exction states. As compared to the case of a two-level quantum dot model, adding the third (bi-exciton) state produces fascinating effects in the optical response of the hybrid system. Specifically, we demonstrate that the system may exhibit picosecond and sub-picosecond self-oscillations and quasi-chaotic behaviour under single-frequency continuous wave excitation. An isolated semiconductor quantum dot does not show such features. The effects originate from competing one-exciton and bi-exciton transitions in the semiconductor quantum dot, triggered by the self-action of the quantum dot via the metal nanoparticle. The key parameter that governs the phenomena mentioned is the ratio of the self-action strength and the bi-exciton shift. The self-oscillation regime can be achieved in practice, in particular, in a heterodimer comprised of a closely spaced ZnS/ZnSe core-shell quantum dot and a spherical silver nanoparticle. The results may have applications in nanodevices for generating trains of ultrashort optical pulses.

  16. Additional observations and notes on the natural history of the prairie rattlesnake (Crotalus viridis) in Colorado. (United States)

    Fitzgerald, Kevin T; Shipley, Bryon K; Newquist, Kristin L; Vera, Rebecca; Flood, Aryn A


    On account of their unique anatomy, physiology, natural history, ecology, and behavior, rattlesnakes make ideal subjects for a variety of different scientific disciplines. The prairie rattlesnake (Crotalus viridis) in Colorado was selected for investigation of its relationship to colonies of black-tailed prairie dogs (Cynomys ludovicianus) with regard to spatial ecology. A total of 31 snakes were anesthetized and had radiotransmitters surgically implanted. In addition, at the time of their capture, all snakes underwent the following: (1) they had bacterial culture taken from their mouths for potential isolation of pathogenic bacteria; (2) similarly, they had cloacal bacterial cultures taken to assess potentially harmful bacteria passed in the feces; and (3) they had blood samples drawn to investigate the presence of any zoonotic agents in the serum of the snakes. The results of the study and their implications are discussed here. Traditionally, a low incidence of bacterial wound infection has been reported following snakebite. Nevertheless, the oral cavity of snakes has long been known to house a wide variety of bacterial flora. In our study, 10 different bacterial species were isolated from the mouths of the rattlesnakes, 6 of which are capable of being zoonotic pathogens and inducing human disease. More studies are necessary to see why more rattlesnake bites do not become infected despite the presence of such pathogenic bacteria. The results of fecal bacteria isolated revealed 13 bacterial species, 12 of which can cause disease in humans. Of the snakes whose samples were cultured, 26% were positive for the presence of the pathogen Salmonella arizonae, one of the causative agents of reptile-related salmonellosis in humans. It has long been reported that captive reptiles have a much higher incidence than wild, free-ranging species. This study shows the incidence of Salmonella in a wild, free-ranging population of rattlesnakes. In addition, Stenotrophomonas

  17. Analysis of [Gossypium capitis-viridis × (G.hirsutum × G.australe2] Trispecific Hybrid and Selected Characteristics.

    Directory of Open Access Journals (Sweden)

    Di Chen

    Full Text Available Speciation is always a contentious and challenging issue following with the presence of gene flow. In Gossypium, there are many valuable resources and wild diploid cotton especially C and B genome species possess some excellent traits which cultivated cotton always lacks. In order to explore character transferring rule from wild cotton to upland tetraploid cotton, the [G. capitis-viridis × (G. hirsutum × G. australe2] triple hybrid was synthesized by interspecies hybridization and chromosome doubling. Morphology comparisons were measured among this hybrid and its parents. It showed that trispecific hybrid F1 had some intermediate morphological characters like leaf style between its parents and some different characters from its parents, like crawl growth characteristics and two kind flower color. It is highly resistant to insects comparing with other cotton species by four year field investigation. By cytogenetic analysis, triple hybrid was further confirmed by meiosis behavior of pollen mother cells. Comparing with regular meiosis of its three parents, it was distinguished by the occurrence of polyads with various numbers of unbalanced microspores and finally generating various abnormal pollen grains. All this phenomenon results in the sterility of this hybrid. This hybrid was further identified by SSR marker from DNA molecular level. It showed that 98 selected polymorphism primers amplified effective bands in this hybrids and its parents. The genetic proportion of three parents in this hybrid is 47.8% from G. hirsutum, 14.3% from G. australe, 7.0% from G. capitis-viridis, and 30.9% recombination bands respectively. It was testified that wild genetic material has been transferred into cultivated cotton and this new germplasm can be incorporated into cotton breeding program.

  18. Lophotrochozoan neuroanatomy: An analysis of the brain and nervous system of Lineus viridis(Nemertea using different staining techniques

    Directory of Open Access Journals (Sweden)

    Loesel Rudi


    Full Text Available Abstract Background The now thriving field of neurophylogeny that links the morphology of the nervous system to early evolutionary events relies heavily on detailed descriptions of the neuronal architecture of taxa under scrutiny. While recent accounts on the nervous system of a number of animal clades such as arthropods, annelids, and molluscs are abundant, in depth studies of the neuroanatomy of nemerteans are still wanting. In this study, we used different staining techniques and confocal laser scanning microscopy to reveal the architecture of the nervous system of Lineus viridis with high anatomical resolution. Results In L. viridis, the peripheral nervous system comprises four distinct but interconnected nerve plexus. The central nervous system consists of a pair of medullary cords and a brain. The brain surrounds the proboscis and is subdivided into four voluminous lobes and a ring of commissural tracts. The brain is well developed and contains thousands of neurons. It does not reveal compartmentalized neuropils found in other animal groups with elaborate cerebral ganglia. Conclusions The detailed analysis of the nemertean nervous system presented in this study does not support any hypothesis on the phylogenetic position of Nemertea within Lophotrochozoa. Neuroanatomical characters that are described here are either common in other lophotrochozoan taxa or are seemingly restricted to nemerteans. Since detailed descriptions of the nervous system of adults in other nemertean species have not been available so far, this study may serve as a basis for future studies that might add data to the unsettled question of the nemertean ground pattern and the position of this taxon within the phylogenetic tree.

  19. Cobalt and manganese stress in the microalga Pavlova viridis (Prymnesiophyceae): Effects on lipid peroxidation and antioxidant enzymes

    Institute of Scientific and Technical Information of China (English)


    Pollution of marine environment has become an issue of major concern in recent years. Serious environmental pollution by heavy metals results from their increasing utilization in industrial processes and because most heavy metals are transported into the marine environment and accumulated without decomposition. The aim of the present study is to investigate the effects on growth, pigments, lipid peroxidation, and some antioxidant enzyme activities of marine microalga Pavlova. viridis, in response to elevated concentrations of cobalt (Co) and manganese (Mn), especially with regard to the involvement of antioxidative defences against heavy metal-induced oxidative stress. In response to Co2+, lipid peroxidation was enhanced compared to the control, as an indication of the oxidative damage caused by metal concentration assayed in the microalgal cells but not Mn2+. Exposure of P. viridis to the two metals caused changes in enzyme activities in a different manner, depending on the metal assayed: after Co2+ treatments, total superoxide dismutase (SOD) activity was irregular, although it was not significantly affected by Mn2+ exposure. Co2+ and Mn2+ stimulated the activities of catalase (CAT) and glutathione (GSH), whereas, glutathione peroxidase (GPX) showed a remarkable increase in activity in response to Co2+ treatments and decreased gradually with Mn2+ concentration, up to 50 μmol/L, and then rose very rapidly, reaching to about 38.98% at 200 μmol/L Mn2+. These results suggest that an activation of some antioxidant enzymes was enhanced, to counteract the oxidative stress induced by the two metals at higher concentration.

  20. Analysis of [Gossypium capitis-viridis × (G.hirsutum × G.australe)2] Trispecific Hybrid and Selected Characteristics. (United States)

    Chen, Di; Wu, Yuxiang; Zhang, Xiling; Li, Fuguang


    Speciation is always a contentious and challenging issue following with the presence of gene flow. In Gossypium, there are many valuable resources and wild diploid cotton especially C and B genome species possess some excellent traits which cultivated cotton always lacks. In order to explore character transferring rule from wild cotton to upland tetraploid cotton, the [G. capitis-viridis × (G. hirsutum × G. australe)2] triple hybrid was synthesized by interspecies hybridization and chromosome doubling. Morphology comparisons were measured among this hybrid and its parents. It showed that trispecific hybrid F1 had some intermediate morphological characters like leaf style between its parents and some different characters from its parents, like crawl growth characteristics and two kind flower color. It is highly resistant to insects comparing with other cotton species by four year field investigation. By cytogenetic analysis, triple hybrid was further confirmed by meiosis behavior of pollen mother cells. Comparing with regular meiosis of its three parents, it was distinguished by the occurrence of polyads with various numbers of unbalanced microspores and finally generating various abnormal pollen grains. All this phenomenon results in the sterility of this hybrid. This hybrid was further identified by SSR marker from DNA molecular level. It showed that 98 selected polymorphism primers amplified effective bands in this hybrids and its parents. The genetic proportion of three parents in this hybrid is 47.8% from G. hirsutum, 14.3% from G. australe, 7.0% from G. capitis-viridis, and 30.9% recombination bands respectively. It was testified that wild genetic material has been transferred into cultivated cotton and this new germplasm can be incorporated into cotton breeding program.

  1. Epstein-Barr virus-encoded latent membrane protein 1 modulates cyclin D1 by c-Jun/Jun B heterodimers

    Institute of Scientific and Technical Information of China (English)

    SONG; Xin; TAO; Yongguang; ZENG; Liang; YANG; Jing; TANG; F


    In our recent studies, we found that LMP1 encoded by Epstein-Barr virus could accelerate the formation of active c-Jun/Jun B heterodimer. We studied the regulation of cyclinD1 by c-Jun/Jun B heterodimers by laser scanning confocal influorescence microscopy, Western blot, luciferase activity assay, super-EMSA and flow cytometry in the Tet-on-LMP1 HNE2 cell line, in which LMP1 expression was regulated by Tet-on system. c-Jun/Jun B heterodimers induced by LMP1 could up regulate cyclin D1 promoter activity and expression. Overexpression of cyclinD1 accelerated the progression of cell cycle.

  2. KARP-1 works as a heterodimer with Ku70, but the function of KARP-1 cannot perfectly replace that of Ku80 in DSB repair. (United States)

    Koike, Manabu; Yutoku, Yasutomo; Koike, Aki


    Ku, the heterodimer of Ku70 and Ku80, plays an essential role in the DNA double-strand break (DSB) repair pathway, i.e., non-homologous end-joining (NHEJ). Two isoforms of Ku80 encoded by the same genes, namely, Ku80 and KARP-1 are expressed and function in primate cells, but not in rodent cells. Ku80 works as a heterodimer with Ku70. However, it is not yet clear whether KARP-1 forms a heterodimer with Ku70 and works as a heterodimer. Although KARP-1 appears to work in NHEJ, its physiological role remains unclear. In this study, we established and characterized EGFP-KARP-1-expressing xrs-6 cell lines, EGFP-KARP-1/xrs-6. We found that nuclear localization signal (NLS) of KARP-1 is localized in the C-terminal region. Our data showed that KARP-1 localizes within the nucleus in NLS-dependent and NLS-independent manner and forms a heterodimer with Ku70, and stabilizes Ku70. On the other hand, EGFP-KARP-1 could not perfectly complement the radiosensitivity and DSB repair activity of Ku80-deficient xrs-6 cells. Furthermore, KARP-1 could not accumulate at DSBs faster than Ku80, although EGFP-KARP-1 accumulates at DSBs. Our data demonstrate that the function of KARP-1 could not perfectly replace that of Ku80 in DSB repair, although KARP-1 has some biochemical properties, which resemble those of Ku80, and works as a heterodimer with Ku70. On the other hand, the number of EGFP-KARP-1-expressing xrs-6 cells showing pan-nuclear γ-H2AX staining significantly increases following X-irradiation, suggesting that KARP-1 may have a novel role in DSB response.

  3. HIV-1 structural proteins serve as PAMPs for TLR2 heterodimers significantly increasing infection and innate immune activation

    Directory of Open Access Journals (Sweden)

    Kenneth Lee Rosenthal


    Full Text Available Immune activation is critical to HIV infection and pathogenesis; however, our understanding of HIV innate immune activation remains incomplete. Recently we demonstrated that soluble TLR2 (sTLR2 physically inhibited HIV-induced, NFκB activation and inflammation, as well as HIV-1 infection. In light of these findings, we hypothesized that HIV-1 structural proteins may serve as pathogen-associated molecular patterns (PAMPs for cellular TLR2 heterodimers. These studies made use of primary human T cells and TZMbl cells stably transformed to express TLR2 (TZMbl-2. Our results demonstrated that cells expressing TLR2 showed significantly increased proviral DNA compared to cells lacking TLR2, and mechanistically this may be due to a TLR2-mediated increased CCR5 expression. Importantly, we show that HIV-1 structural proteins, p17, p24, and gp41 act as viral PAMPs signalling through TLR2 and its heterodimers leading to significantly increased immune activation via the NFκB signaling pathway. Using co-immunoprecipitation and a dot blot method, we demonstrated direct protein interactions between these viral PAMPs and TLR2, while only p17 and gp41 bound to TLR1. Specifically, TLR2/1 heterodimer recognized p17 and gp41, while p24 lead to immune activation through TLR2/6. These results were confirmed using TLR2/1 siRNA knock down assays which ablated p17 and gp41-induced cellular activation and through studies of HEK293 cells expressing selected TLRs. Interestingly, our results show in the absence of TLR6, p24 bound to TLR2 and blocked p17 and gp41-induced activation, thus providing a novel mechanism by which HIV-1 can manipulate innate sensing. Taken together, our results identified, for the first time, novel HIV-1 PAMPs that play a role in TLR2-mediated cellular activation and increased proviral DNA. These findings have important implications for our fundamental understanding of HIV-1 immune activation and pathogenesis, as well as HIV-1 vaccine development.

  4. 大青叶蝉寄主植物名录%Catalogue of Host Plants of Cicadella viridi L.(Hemiptera: Cicadellidae)

    Institute of Scientific and Technical Information of China (English)

    高宇; 韩琪; 徐博


    在田间调查和查阅国内外文献的基础上,整理出大青叶蝉(Cicadella viridis L.)寄主植物名录,主要涉及裸子植物、双子叶植物和单子叶植物,共计3纲65科275种(含变型、亚种和变种).

  5. Spermadhesin PSP-I/PSP-II heterodimer induces migration of polymorphonuclear neutrophils into the uterine cavity of the sow. (United States)

    Rodriguez-Martinez, H; Saravia, F; Wallgren, M; Martinez, E A; Sanz, L; Roca, J; Vazquez, J M; Calvete, J J


    Seminal plasma (SP) is a complex fluid which exerts biological actions in the female reproductive tract. In pigs, SP elicits endometrial inflammation and consequent immune changes after mating. This study tested whether heparin-binding spermadhesins (HBPs) and the heterodimer of porcine sperm adhesions I and II (PSP-I/PSP-II) in SP recruit different lymphocyte subsets (CD2(+), CD4(+) and CD8(+) T cells) or polymorphonuclear leukocytes (PMNs) to the superficial endometrium or luminal epithelium and lumen, respectively, of oestrous sows. In Experiment 1, endometrial biopsies were taken between 2 and 120 min after infusion of uterine horns with HBPs, PSP-I/PSP-II or saline and evaluated by immunohistochemistry or histology. In Experiment 2, the uterus of oestrous sows was infused with PSP-I/PSP-II or saline to assess PMN numbers in the uterine lumen 3h later. PSP-I/PSP-II elicited CD2+ T cell recruitment from 10 min, and CD8(+) T cells from 60 min after infusion, while HBPs increased CD4(+) T cell recruitment by 120 min. PSP-I/PSP-II but not HBPs induced PMN migration to the surface epithelium by 10 min. PMN numbers were elevated 5-fold by 30 min and 7-fold from 60 min, with PMNs detectable in the lumen from 30 min after infusion. Six-fold more PMNs were collected from the uterine lumen of PSP-I/PSP-II-infused sows compared to controls at 3h after infusion. These data show that PSP-I/PSP-II heterodimer in seminal plasma has a predominant role in triggering the recruitment of uterine PMNs and T cells after mating, initiating a cascade of transient and long-lasting immunological events.

  6. BMP2/7 heterodimer can modulate all cellular events of the in vitro rankl-mediated osteoclastogenesis, respectively, in different dose patterns

    NARCIS (Netherlands)

    Zheng, Y.; Wang, L.; Zhang, X.; Gu, Z.; Wu, G.


    Bone morphogenetic protein (BMP) heterodimers can trigger and sustain osteoblastic bone regeneration in significantly lower dosages than BMP homodimers. However, their effects on osteoclastic activity—a paramount coupling process with ostoblastic activity—remain undocumented. In this study, we delin

  7. Low-dose rhBMP2/7 heterodimer to reconstruct peri-implant bone defects: a micro-CT evaluation

    NARCIS (Netherlands)

    Wang, J.; Zheng, Y.; Zhao, J.; Liu, T.; Gao, L.; Gu, Z.; Wu, G.


    Objectives To delineate the dynamic micro-architectures of bone induced by low-dose bone morphogenetic protein (BMP)-2/7 heterodimer in peri-implant bone defects compared to BMP2 and BMP7 homodimer. Material and Methods Peri-implant bone defects (8 mm in diameter, 4 mm in depth) were created surroun

  8. Evidence of accelerated evolution and ectodermal-specific expression of presumptive BDS toxin cDNAs from Anemonia viridis. (United States)

    Nicosia, Aldo; Maggio, Teresa; Mazzola, Salvatore; Cuttitta, Angela


    Anemonia viridis is a widespread and extensively studied Mediterranean species of sea anemone from which a large number of polypeptide toxins, such as blood depressing substances (BDS) peptides, have been isolated. The first members of this class, BDS-1 and BDS-2, are polypeptides belonging to the β-defensin fold family and were initially described for their antihypertensive and antiviral activities. BDS-1 and BDS-2 are 43 amino acid peptides characterised by three disulfide bonds that act as neurotoxins affecting Kv3.1, Kv3.2 and Kv3.4 channel gating kinetics. In addition, BDS-1 inactivates the Nav1.7 and Nav1.3 channels. The development of a large dataset of A. viridis expressed sequence tags (ESTs) and the identification of 13 putative BDS-like cDNA sequences has attracted interest, especially as scientific and diagnostic tools. A comparison of BDS cDNA sequences showed that the untranslated regions are more conserved than the protein-coding regions. Moreover, the KA/KS ratios calculated for all pairwise comparisons showed values greater than 1, suggesting mechanisms of accelerated evolution. The structures of the BDS homologs were predicted by molecular modelling. All toxins possess similar 3D structures that consist of a triple-stranded antiparallel β-sheet and an additional small antiparallel β-sheet located downstream of the cleavage/maturation site; however, the orientation of the triple-stranded β-sheet appears to differ among the toxins. To characterise the spatial expression profile of the putative BDS cDNA sequences, tissue-specific cDNA libraries, enriched for BDS transcripts, were constructed. In addition, the proper amplification of ectodermal or endodermal markers ensured the tissue specificity of each library. Sequencing randomly selected clones from each library revealed ectodermal-specific expression of ten BDS transcripts, while transcripts of BDS-8, BDS-13, BDS-14 and BDS-15 failed to be retrieved, likely due to under-representation in our

  9. Morphostasis in a novel eukaryote illuminates the evolutionary transition from phagotrophy to phototrophy: description of Rapaza viridis n. gen. et sp. (Euglenozoa, Euglenida

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    Yamaguchi Aika


    Full Text Available Abstract Background Morphostasis of traits in different species is necessary for reconstructing the evolutionary history of complex characters. Studies that place these species into a molecular phylogenetic context test hypotheses about the transitional stages that link divergent character states. For instance, the transition from a phagotrophic mode of nutrition to a phototrophic lifestyle has occurred several times independently across the tree of eukaryotes; one of these events took place within the Euglenida, a large group of flagellates with diverse modes of nutrition. Phototrophic euglenids form a clade that is nested within lineages of phagotrophic euglenids and that originated through a secondary endosymbiosis with green algae. Although it is clear that phototrophic euglenids evolved from phagotrophic ancestors, the morphological disparity between species representing these different nutritional modes remains substantial. Results We cultivated a novel marine euglenid, Rapaza viridis n. gen. et sp. ("green grasper", and a green alga, Tetraselmis sp., from the same environment. Cells of R. viridis were comprehensively characterized with light microscopy, SEM, TEM, and molecular phylogenetic analysis of small subunit rDNA sequences. Ultrastructural and behavioral observations demonstrated that this isolate habitually consumes a specific strain of Tetraselmis prey cells and possesses a functional chloroplast that is homologous with other phototrophic euglenids. A novel feeding apparatus consisting of a reduced rod of microtubules facilitated this first and only example of mixotrophy among euglenids. R. viridis also possessed a robust photoreception apparatus, two flagella of unequal length, euglenoid movement, and a pellicle consisting of 16 strips and one (square-shaped whorl of posterior strip reduction. The molecular phylogenetic data demonstrated that R. viridis branches as the nearest sister lineage to phototrophic euglenids

  10. European green lizard (Lacerta viridis) personalities: Linking behavioural types to ecologically relevant traits at different ontogenetic stages. (United States)

    Bajer, Katalin; Horváth, Gergely; Molnár, Orsolya; Török, János; Garamszegi, László Zsolt; Herczeg, Gábor


    Consistent individual differences within (animal personality) and across (behavioural syndrome) behaviours became well recognized during the past decade. Nevertheless, our knowledge about the evolutionary and developmental mechanisms behind the phenomena is still incomplete. Here, we explored if risk-taking and exploration were consistent and linked to different ecologically relevant traits in wild-caught adult male European green lizards (Lacerta viridis) and in their 2-3 weeks old laboratory-reared offspring. Both adults and juveniles displayed animal personality, consistency being higher in juveniles. We found correlation between risk-taking and exploration (suggestive of a behavioural syndrome) only in adults. Juveniles were more explorative than adults. Large or ectoparasite-free adult males were more explorative than small or parasitized males. Juvenile females tended to be more risk-taking than males. Behaviour of fathers and their offspring did not correlate. We conclude that European green lizards show high behavioural consistency and age is an important determinant of its strength and links to traits likely affecting fitness.

  11. Suspended micro-sized PVC particles impair the performance and decrease survival in the Asian green mussel Perna viridis. (United States)

    Rist, Sinja Elena; Assidqi, Khoirunnisa; Zamani, Neviaty Putri; Appel, Daniel; Perschke, Myriam; Huhn, Mareike; Lenz, Mark


    Marine bivalves are known to ingest microplastics, but information on the consequences for their physiological performance is limited. To investigate a potential exposure pathway that has not yet been addressed, we mimicked the resuspension of microplastics from the sediment in a laboratory exposure experiment. For this, we exposed the Asian green mussel Perna viridis to 4 concentrations (0mg/l, 21.6mg/l, 216mg/l, 2160mg/l) of suspended polyvinylchloride (PVC) particles (1-50μm) for two 2-hour-time-periods per day. After 44days, mussel filtration and respiration rates as well as byssus production were found to be a negative function of particle concentration. Furthermore, within 91days of exposure, mussel survival declined with increasing PVC abundance. These negative effects presumably go back to prolonged periods of valve closure as a reaction to particle presence. We suggest that microplastics constitute a new seston component that exerts a stress comparable to natural suspended solids.

  12. Preliminary assessment of growth and survival of green alder (Alnus viridis), a potential biological stabilizer on fly ash disposal sites

    Institute of Scientific and Technical Information of China (English)

    Marcin Pietrzykowski; Wojciech Krzaklewski; Bartłomiej Wos´


    This paper presents preliminary assessment of seedling survival and growth of green alder (Alnus viridis (Chaix) DC. in Lam. & DC.) planted on fly ash disposal sites. This kind of post-industrial site is extremely hard to biologically stabilize without top-soiling. The experiment started with surface preparation using NPK start-up mineral fertilizer at 60–36–36 kg ha-1 followed by initial stabil-ization through hydro-seeding with biosolids (sewage sludge 4 Mg ha-1 dry mass) and a mixture of grasses (Dactylis glomerata L. and Lolium multiflorum Lam.) (200 kg ha-1). Subsequently, three-years-old green alder seedlings were planted in plots on two substrate variants:the control (directly on combustion waste) and plots with 3 dm3 lignite culm from a nearby mine introduced into the planting pit. Five years of preliminary monitoring show good survival seedling rates and growth parameters (height (h), average increase in height (△h), number of shoots (Lo) and leaf nitrogen supply in the fly ash disposal habitat. Treatment of the site with a combination of lignite culm in planting pits and preliminary surface preparation by hydro-seeding and mineral fertilization had the most positive effect on green alder seedling parameters. The results indicate that it is possible and beneficial to use green alder for biological stabilization on fly ash disposal sites.

  13. NMR-based metabolomic studies on the toxicological effects of cadmium and copper on green mussels Perna viridis

    Energy Technology Data Exchange (ETDEWEB)

    Wu Huifeng [Section of Marine Ecology and Biotechnology, Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: [Section of Marine Ecology and Biotechnology, Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)


    Traditional toxicology studies have focused on selected biomarkers to characterize the biological stress induced by metals in marine organisms. In this study, a system biology tool, metabolomics, was applied to the marine mussel Perna viridis to investigate changes in the metabolic profiles of soft tissue as a response to copper (Cu) and cadmium (Cd), both as single metal and as a mixture. The major metabolite changes corresponding to metal exposure are related to amino acids, osmolytes, and energy metabolites. Following metal exposure for 1 week, there was a significant increase in the levels of branched chain amino acids, histidine, glutamate, glutamine, hypotaurine, dimethylglycine, arginine and ATP/ADP. For the Cu + Cd co-exposed mussels, the levels of lactate, branched chain amino acid, succinate, and NAD increased, whereas the levels of glucose, glycogen, and ATP/ADP decreased, indicating a different metabolic profile for the single metal exposure groups. After 2 weeks of exposure, the mussels showed acclimatization to Cd exposure based on the recovery of some metabolites. However, the metabolic profile induced by the metal mixture was very similar to that from Cu exposure, suggesting that Cu dominantly induced the metabolic disturbances. Both Cu and Cd may lead to neurotoxicity, disturbances in energy metabolism, and osmoregulation changes. These results demonstrate the high applicability and reliability of NMR-based metabolomics in interpreting the toxicological mechanisms of metals using global metabolic biomarkers.

  14. Effects of aqueous and dietary preexposure and resulting body burden on silver biokinetics in the green mussel Perma viridis. (United States)

    Shi, Dalin; Blackmore, Graham; Wang, Wen-Xiong


    To determine whether preexposure of green mussel Perna viridis to Ag influenced metal uptake kinetics we compared various physiological indicators of metal uptake kinetics between the control mussels and mussels preexposed to Ag in both diet and water at different levels (up to 5 weeks). In all preexposed mussels, the assimilation of Ag increased by 1.1-3.0 times with increasing Ag body concentration (0.651-19.3 microg g(-1)) as compared with the controls (Ag body concentration of 0.311-0.479 microg g(-1)), whereas the efflux rate constants decreased by 45-88%. There was no significant increase in Ag associated with the metallothionein-like protein (MTLP) fraction following exposure of the mussels to Ag through either the dissolved or food phase. The clearance rates were little affected or depressed byAg preexposure, and the relationship between the Ag influx rate from the dissolved phase and the Ag preexposure was somewhat complicated. The influx rate decreased with increasing Ag body burden at <2.5 microg g(-1), above which it increased with increasing Ag body burden. Our results indicate that the mussels may modify physiological processes to ambient chronic Ag exposure, consequently accumulating more Ag. Ag body concentration in these mussels may therefore increase disproportionally in response to increasing Ag concentration in the ambient environments. Ag preexposure and resulting body burden should be considered carefully when interpreting the observed Ag concentration in biomonitoring animals to evaluate the Ag pollution in seawater.

  15. Interaction of mumps virus V protein variants with STAT1-STAT2 heterodimer: experimental and theoretical studies

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    Reyes-Leyva Julio


    Full Text Available Abstract Background Mumps virus V protein has the ability to inhibit the interferon-mediated antiviral response by inducing degradation of STAT proteins. Two virus variants purified from Urabe AM9 mumps virus vaccine differ in their replication and transcription efficiency in cells primed with interferon. Virus susceptibility to IFN was associated with insertion of a non-coded glycine at position 156 in the V protein (VGly of one virus variant, whereas resistance to IFN was associated with preservation of wild-type phenotype in the V protein (VWT of the other variant. Results VWT and VGly variants of mumps virus were cloned and sequenced from Urabe AM9 vaccine strain. VGly differs from VWT protein because it possesses an amino acid change Gln103Pro (Pro103 and the Gly156 insertion. The effect of V protein variants on components of the interferon-stimulated gene factor 3 (ISGF3, STAT1 and STAT2 proteins were experimentally tested in cervical carcinoma cell lines. Expression of VWT protein decreased STAT1 phosphorylation, whereas VGly had no inhibitory effect on either STAT1 or STAT2 phosphorylation. For theoretical analysis of the interaction between V proteins and STAT proteins, 3D structural models of VWT and VGly were predicted by comparing with simian virus 5 (SV5 V protein structure in complex with STAT1-STAT2 heterodimer. In silico analysis showed that VWT-STAT1-STAT2 complex occurs through the V protein Trp-motif (W174, W178, W189 and Glu95 residue close to the Arg409 and Lys415 of the nuclear localization signal (NLS of STAT2, leaving exposed STAT1 Lys residues (K85, K87, K296, K413, K525, K679, K685, which are susceptible to proteasome degradation. In contrast, the interaction between VGly and STAT1-STAT2 heterodimer occurs in a region far from the NLS of STAT2 without blocking of Lys residues in both STAT1 and STAT2. Conclusions Our results suggest that VWT protein of Urabe AM9 strain of mumps virus may be more efficient than VGly to

  16. Thyroid Hormone Regulates the mRNA Expression of Small Heterodimer Partner through Liver Receptor Homolog-1

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    Hwa Young Ahn


    Full Text Available BackgroundExpression of hepatic cholesterol 7α-hydroxylase (CYP7A1 is negatively regulated by orphan nuclear receptor small heterodimer partner (SHP. In this study, we aimed to find whether thyroid hormone regulates SHP expression by modulating the transcriptional activities of liver receptor homolog-1 (LRH-1.MethodsWe injected thyroid hormone (triiodothyronine, T3 to C57BL/6J wild type. RNA was isolated from mouse liver and used for microarray analysis and quantitative real-time polymerase chain reaction (PCR. Human hepatoma cell and primary hepatocytes from mouse liver were used to confirm the effect of T3 in vitro. Promoter assay and electrophoretic mobility-shift assay (EMSA were also performed using human hepatoma cell lineResultsInitial microarray results indicated that SHP expression is markedly decreased in livers of T3 treated mice. We confirmed that T3 repressed SHP expression in the liver of mice as well as in mouse primary hepatocytes and human hepatoma cells by real-time PCR analysis. LRH-1 increased the promoter activity of SHP; however, this increased activity was markedly decreased after thyroid hormone receptor β/retinoid X receptor α/T3 administration. EMSA revealed that T3 inhibits specific LRH-1 DNA binding.ConclusionWe found that thyroid hormone regulates the expression of SHP mRNA through interference with the transcription factor, LRH-1.

  17. A Pleiotropic Role for the Orphan Nuclear Receptor Small Heterodimer Partner in Lipid Homeostasis and Metabolic Pathways

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    Gabriella Garruti


    Full Text Available Nuclear receptors (NRs comprise one of the most abundant classes of transcriptional regulators of metabolic diseases and have emerged as promising pharmaceutical targets. Small heterodimer partner (SHP; NR0B2 is a unique orphan NR lacking a DNA-binding domain but contains a putative ligand-binding domain. SHP is a transcriptional regulator affecting multiple key biological functions and metabolic processes including cholesterol, bile acid, and fatty acid metabolism, as well as reproductive biology and glucose-energy homeostasis. About half of all mammalian NRs and several transcriptional coregulators can interact with SHP. The SHP-mediated repression of target transcription factors includes at least three mechanisms including direct interference with the C-terminal activation function 2 (AF2 coactivator domains of NRs, recruitment of corepressors, or direct interaction with the surface of NR/transcription factors. Future research must focus on synthetic ligands acting on SHP as a potential therapeutic target in a series of metabolic abnormalities. Current understanding about the pleiotropic role of SHP is examined in this paper, and principal metabolic aspects connected with SHP function will be also discussed.

  18. Effects of coating molecules on the magnetic heating properties of Au-Fe3O4 heterodimer nanoparticles (United States)

    Yamamoto, Y.; Ogasawara, J.; Himukai, H.; Itoh, T.


    In this paper, we report the heating properties of gold-magnetite (Au-Fe3O4) heterodimer nanoparticles (NPs) subjected to an alternating magnetic field. The Au-Fe3O4 NPs coated with oleic acid and oleylamine (OA) were synthesized through a method that combines seed mediation and high-temperature decomposition. The coating was replaced with dimercaptosuccinic acid (DMSA) by the ligand-exchange method. The specific absorption rates (SARs) for the OA- and DMSA-coated Au-Fe3O4 NPs coated with OA and DMSA at room temperature were determined through the calorimetric and magnetometric methods. SAR depended on the square of the magnetic field H up to an H value of 4 kA/m. The absolute value of the SAR for DMSA-coated NPs is about fivefold higher than that of the OA-coated NPs. The AC magnetic hysteresis measurements showed the recovery of the magnetic volume and the decrease in the magnetic anisotropy of the DMSA-coated NPs relative to those of the OA-coated NPs. These results suggest that the protective agent influences the magnetic properties of magnetite NPs via gold NPs.

  19. Critical role of RanBP2-mediated SUMOylation of Small Heterodimer Partner in maintaining bile acid homeostasis. (United States)

    Kim, Dong-Hyun; Kwon, Sanghoon; Byun, Sangwon; Xiao, Zhen; Park, Sean; Wu, Shwu-Yuan; Chiang, Cheng-Ming; Kemper, Byron; Kemper, Jongsook Kim


    Bile acids (BAs) are recently recognized signalling molecules that profoundly affect metabolism. Because of detergent-like toxicity, BA levels must be tightly regulated. An orphan nuclear receptor, Small Heterodimer Partner (SHP), plays a key role in this regulation, but how SHP senses the BA signal for feedback transcriptional responses is not clearly understood. We show an unexpected function of a nucleoporin, RanBP2, in maintaining BA homoeostasis through SUMOylation of SHP. Upon BA signalling, RanBP2 co-localizes with SHP at the nuclear envelope region and mediates SUMO2 modification at K68, which facilitates nuclear transport of SHP and its interaction with repressive histone modifiers to inhibit BA synthetic genes. Mice expressing a SUMO-defective K68R SHP mutant have increased liver BA levels, and upon BA- or drug-induced biliary insults, these mice exhibit exacerbated cholestatic pathologies. These results demonstrate a function of RanBP2-mediated SUMOylation of SHP in maintaining BA homoeostasis and protecting from the BA hepatotoxicity.

  20. Retinoic acid regulates several genes in bile acid and lipid metabolism via upregulation of small heterodimer partner in hepatocytes. (United States)

    Mamoon, Abulkhair; Subauste, Angela; Subauste, Maria C; Subauste, Jose


    Retinoic acid (RA) affects multiple aspects of development, embryogenesis and cell differentiation processes. The liver is a major organ that stores RA suggesting that retinoids play an important role in the function of hepatocytes. In our previous studies, we have demonstrated the involvement of small heterodimer partner (SHP) in RA-induced signaling in a non-transformed hepatic cell line AML 12. In the present study, we have identified several critical genes in lipid homeostasis (Apoa1, Apoa2 and ApoF) that are repressed by RA-treatment in a SHP dependent manner, in vitro and also in vivo with the use of the SHP null mice. In a similar manner, RA also represses several critical genes involved in bile acid metabolism (Cyp7a1, Cyp8b1, Mdr2, Bsep, Baat and Ntcp) via upregulation of SHP. Collectively our data suggest that SHP plays a major role in RA-induced potential changes in pathophysiology of metabolic disorders in the liver.

  1. Two-Step Hydrothermal Synthesis of Bifunctional Hematite-Silver Heterodimer Nanoparticles for Potential Antibacterial and Anticancer Applications (United States)

    Trang, Vu Thi; Tam, Le Thi; Phan, Vu Ngoc; Van Quy, Nguyen; Huy, Tran Quang; Le, Anh-Tuan


    In recent years, the development of composite nanostructures containing noble metal and magnetic nanocrystals has attracted much interest because they offer a promising avenue for multifunctional applications in nanomedicine and pharmacotherapy. In this work, we present a facile two-step hydrothermal approach for the synthesis of bifunctional heterodimer nanoparticles (HDNPs) composed of hematite nanocubes (α-Fe2O3 NCs) and silver nanoparticles (Ag-NPs). The formation and magnetic property of α-Fe2O3-Ag HDNPs was analyzed by transmission electron microscopy, x-ray diffraction and vibrating sample magnetometer. Interestingly, the hydrothermal-synthesized α-Fe2O3-Ag HDNPs were found to display significant antibacterial activity against three types of infectious bacteria. The cytotoxicity of α-Fe2O3-Ag nanocomposite against lung cancer A549 cell line was investigated and compared with that of pure α-Fe2O3 NCs and Ag-NPs. The obtained results reveal that the α-Fe2O3-Ag nanocomposite exhibited higher anticancer performance than that of pure Ag-NPs, whereas pure α-Fe2O3 NCs were not cytotoxic to the tested cells. The inhibitory concentration (IC50) of the α-Fe2O3-Ag nanocomposite was found at 20.94 μg/mL. With the aforementioned properties, α-Fe2O3-Ag HDNPs showed a high potential as a multifunctional material for advanced biomedicine and nanotherapy applications.

  2. Heterodimer formation between c-Jun and Jun B proteins mediated by Epstein Barr virus encoded latent membrane protein 1

    Institute of Scientific and Technical Information of China (English)

    SONG Xin; TAO Yongguang; TAN Yunnian; Leo M. Lee; DENG Xiyun; WU Qiao; CAO Ya


    Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) may trigger the transcription factor AP-1 including c-Jun and c-fos. In this report, using a Tet-on LMP1 HNE2 cell line which is a dual-stable LMP1 integrated nasopharyngeal carcinoma (NPC) cell line and the expression of LMP1 in which could be regulated by the Tet-on system, we show that Jun B can efficiently form a new heterodimeric complex with the c-Jun protein under the regulation of LMP1, phosphorylation of c-Jun (ser 63, ser 73) and Jun B is involved in the process of the new heterodimeric formation. We also find that this heterodimeric form can bind to the AP-1 consensus sequence. Transfection studies suggest that JNK interaction protein (JIP) could inhibit the heterodimer formation of c-Jun and Jun B through blocking the AP-1 signaling pathway triggered by LMP1. The interaction and function between c-Jun protein and Jun B protein increase the repertoire of possible regulatory complexes by LMP1 that could play an important role in the regulation of transcription of specific cellular genes in the process of genesis of nasopharyngeal carcinoma.

  3. Validating Internal Control Genes for the Accurate Normalization of qPCR Expression Analysis of the Novel Model Plant Setaria viridis.

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    Julia Lambret-Frotté

    Full Text Available Employing reference genes to normalize the data generated with quantitative PCR (qPCR can increase the accuracy and reliability of this method. Previous results have shown that no single housekeeping gene can be universally applied to all experiments. Thus, the identification of a suitable reference gene represents a critical step of any qPCR analysis. Setaria viridis has recently been proposed as a model system for the study of Panicoid grasses, a crop family of major agronomic importance. Therefore, this paper aims to identify suitable S. viridis reference genes that can enhance the analysis of gene expression in this novel model plant. The first aim of this study was the identification of a suitable RNA extraction method that could retrieve a high quality and yield of RNA. After this, two distinct algorithms were used to assess the gene expression of fifteen different candidate genes in eighteen different samples, which were divided into two major datasets, the developmental and the leaf gradient. The best-ranked pair of reference genes from the developmental dataset included genes that encoded a phosphoglucomutase and a folylpolyglutamate synthase; genes that encoded a cullin and the same phosphoglucomutase as above were the most stable genes in the leaf gradient dataset. Additionally, the expression pattern of two target genes, a SvAP3/PI MADS-box transcription factor and the carbon-fixation enzyme PEPC, were assessed to illustrate the reliability of the chosen reference genes. This study has shown that novel reference genes may perform better than traditional housekeeping genes, a phenomenon which has been previously reported. These results illustrate the importance of carefully validating reference gene candidates for each experimental set before employing them as universal standards. Additionally, the robustness of the expression of the target genes may increase the utility of S. viridis as a model for Panicoid grasses.

  4. Phylogenetic relationships among the Caribbean members of the Cliona viridis complex (Porifera, Demospongiae, Hadromerida) using nuclear and mitochondrial DNA sequences. (United States)

    Escobar, Dairo; Zea, Sven; Sánchez, Juan A


    Species complexes - groups of closely related species in which intraspecific and interspecific variability overlap - have generated considerable interest and study. Frequently, members of a species complex do not have complete reproductive isolation; therefore, the complex may go through extensive gene flow. In the Caribbean Sea, some encrusting and excavating sponges of the genus Cliona (Porifera, Hadromerida, Clionaidae) are grouped within the great "Cliona viridis" complex because of their morphological similarities. This study examined the evolutionary relationships of the Caribbean members of this complex (C. caribbaea, C. tenuis, C. aprica and C. varians) and related taxa based on nuclear (ITS1 and ITS2) and mitochondrial (3' end of ND6) DNA sequences. The intragenomic ITS variation and its secondary structures were evaluated using a mixed approach of Denaturing Gradient Gel Electrophoresis (DGGE), DNA sequencing and secondary structure prediction. Considerable intragenomic variation was found in all the species, with apparently functional ITS1 and ITS2 secondary structures. Despite the subtle but clear morphological differentiation in these excavating sponges, the intragenomic copies of C. caribbaea, C. tenuis and C. aprica had a polyphyletic placement in the ITS1 and ITS2 genealogies and very low divergence. Therefore, it is clear that these species constitute a species complex (herein called Ct-complex). Genetic distances within the Ct-complex revealed that an important part of the interspecific variation overlapped with intraspecific variation, suggesting either incomplete lineage sorting or extensive gene flow. In contrast, C. varians and an unidentified "Pione" species emerged as monophyletic clades, being the closest sister groups to the Ct-complex. Additionally, our results support that C. laticavicola and C. delitrix conform a monophyletic group, but absence of reciprocal monophyly in these species suggests they may be life stages or ecophenotypes of

  5. Natural product Celastrol destabilizes tubulin heterodimer and facilitates mitotic cell death triggered by microtubule-targeting anti-cancer drugs.

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    Hakryul Jo

    Full Text Available BACKGROUND: Microtubule drugs are effective anti-cancer agents, primarily due to their ability to induce mitotic arrest and subsequent cell death. However, some cancer cells are intrinsically resistant or acquire a resistance. Lack of apoptosis following mitotic arrest is thought to contribute to drug resistance that limits the efficacy of the microtubule-targeting anti-cancer drugs. Genetic or pharmacological agents that selectively facilitate the apoptosis of mitotic arrested cells present opportunities to strengthen the therapeutic efficacy. METHODOLOGY AND PRINCIPAL FINDINGS: We report a natural product Celastrol targets tubulin and facilitates mitotic cell death caused by microtubule drugs. First, in a small molecule screening effort, we identify Celastrol as an inhibitor of neutrophil chemotaxis. Subsequent time-lapse imaging analyses reveal that inhibition of microtubule-mediated cellular processes, including cell migration and mitotic chromosome alignment, is the earliest events affected by Celastrol. Disorganization, not depolymerization, of mitotic spindles appears responsible for mitotic defects. Celastrol directly affects the biochemical properties of tubulin heterodimer in vitro and reduces its protein level in vivo. At the cellular level, Celastrol induces a synergistic apoptosis when combined with conventional microtubule-targeting drugs and manifests an efficacy toward Taxol-resistant cancer cells. Finally, by time-lapse imaging and tracking of microtubule drug-treated cells, we show that Celastrol preferentially induces apoptosis of mitotic arrested cells in a caspase-dependent manner. This selective effect is not due to inhibition of general cell survival pathways or mitotic kinases that have been shown to enhance microtubule drug-induced cell death. CONCLUSIONS AND SIGNIFICANCE: We provide evidence for new cellular pathways that, when perturbed, selectively induce the apoptosis of mitotic arrested cancer cells, identifying a

  6. Concentrations of heavy metals (Cu, Cd, Zn and Ni) and PAHs in Perna viridis collected from seaport and non-seaport waters in the Straits of Johore. (United States)

    Yap, C K; Shahbazi, A; Zakaria, M P


    In this study, the ranges of pollutants found in the soft tissues of Perna viridis collected from Kg. Masai and Kg. Sg. Melayu, both located in the Straits of Johore, were 0.85-1.58 μg/g dry weight (dw) for Cd, 5.52-12.2 μg/g dw for Cu, 5.66-8.93 μg/g dw for Ni and 63.4-72.3 μg/g dw for Zn, and 36.4-244 ng/g dry weight for ∑PAHs. Significantly (p Melayu population. The ratios of low molecular weight/high molecular weight hydrocarbons (2.94-3.42) and fluoranthene/pyrene (0.43-0.45) in mussels from both sites indicated the origin of the PAHs to be mainly petrogenic. This study has demonstrated the utility of using the soft tissues of P. viridis as a biomonitor of PAH contamination and bioavailability in the coastal waters of Peninsular Malaysia.

  7. Extracts from Cladiella australis, Clavularia viridis and Klyxum simplex (Soft Corals are Capable of Inhibiting the Growth of Human Oral Squamous Cell Carcinoma Cells

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    Guey-Horng Wang


    Full Text Available Many biomedical products have already been obtained from marine organisms. In order to search more therapeutic drugs against cancer, this study demonstrates the cytotoxicity effects of Cladiella australis, Clavularia viridis and Klyxum simplex extractson human oral squamous cell carcinoma (SCC4, SCC9 and SCC25 cells using cell adhesion and cell viability assay. The morphological alterations in SCCs cells after treatment with three extracts, such as typical nuclear condensation, nuclear fragmentation and apoptotic bodies of cells were demonstrated by Hoechst stain. Flow cytometry indicated that three extracts sensitized SCC25 cells in the G0/G1 and S-G2/M phases with a concomitant significantly increased sub-G1 fraction, indicating cell death by apoptosis. This apoptosis process was accompanied by activation of caspase-3 expression after SCC25 cells were treated with three extracts. Thereby, it is possible that extracts of C. australis, C. viridis and K. simplex cause apoptosis of SCCs and warrant further research investigating the possible anti-oral cancer compounds in these soft corals.

  8. Impact of marine pollution in green mussel Perna viridis from four coastal sites in Karachi, Pakistan, North Arabian Sea: histopathological observations. (United States)

    Khan, Muhammad Iftikhar; Ayub, Zarrien; Siddiqui, Ghazala


    Pathological changes are regarded as a standard technique to monitor the effects of pollutants in marine animals. Histopathological examination of the population of green mussel Perna viridis (L.) from four sites in Pakistan, namely, Manora Channel, Rehri Creek, Sandspit Backwaters and Bhanbore was conducted. The first three sites are on the Karachi coast, whereas the fourth one, Bhanbore is situated outside Karachi, and is considered to be less polluted. Two types of parasites, Rickettsia-like organisms and metacestode were found in the mussels studied. In the present study, we observed various pathological lesions, such as inflammatory responses, granulocytomas, lipofuscin pigments, vacuolation in the digestive gland and gonads, lamellar fusion and dilated hemolymphatic sinus in the gills of P. viridis. These observations indicate the extent of environmental pollution in the studied areas. Although, Bhanbore is considered to be relatively less polluted compared to other three sites, the present results have revealed that the waters of Bhanbore are also polluted as evidenced by the pathological changes observed in the mussels collected from there.

  9. Correlation analysis of symmetry breaking in the surface nanostructure ordering: case study of the ventral scale of the snake Morelia viridis (United States)

    Kovalev, A.; Filippov, A.; Gorb, S. N.


    In contrast to the majority of inorganic or artificial materials, there is no ideal long-range ordering of structures on the surface in biological systems. Local symmetry of the ordering on biological surfaces is also often broken. In the present paper, the particular symmetry violation was analyzed for dimple-like nano-pattern on the belly scales of the skin of the pythonid snake Morelia viridis using correlation analysis and statistics of the distances between individual nanostructures. The results of the analysis performed on M. viridis were compared with a well-studied nano-nipple pattern on the eye of the sphingid moth Manduca sexta, used as a reference. The analysis revealed non-random, but very specific symmetry violation. In the case of the moth eye, the nano-nipple arrangement forms a set of domains, while in the case of the snake skin, the nano-dimples arrangement resembles an ordering of particles (molecules) in amorphous (glass) state. The function of the nano-dimples arrangement may be to provide both friction and strength isotropy of the skin. A simple model is suggested, which provides the results almost perfectly coinciding with the experimental ones. Possible mechanisms of the appearance of the above nano-formations are discussed.

  10. New Karyological and Morphometric Data on Poorly Known Bufo surdus and Bufo luristanicus in Comparison with Data of Diploid Green Toads of the Bufo viridis Complex from South of Iran

    Institute of Scientific and Technical Information of China (English)

    Fatemeh FAKHARZAEH; Jamshid DARVISH; Haji Gholi KAMI; Fereshteh GHASEMZADEH; Eskandar RASTEGAR-POUYANI


    Previous studies on the Bufo viridis complex, which is distributed broadly across Iran, are incomplete and restricted to a few regions or a few samples. In this paper a new detailed study on the B. viridis complex in southern of Iran (from West to East) is presented. The analysis of 18 morphometric characters with univariate and multivariate methods reveals significant differences between three members of the B. viridis complex namely B. variabilis, B. luristanicus, and B. surdus distributed in southern part of Iran. Our result help to resolve an old taxonomic problem about B. surdus subgroup (taxa closely related to B. surdus) conifrming that B. luristanicus and B. surdus are distinct species. Moreover, for the ifrst time we report and describe karyotype details of B. luristanicus and B. surdus which conifrmed that they are diploid. Karyological studies demonstrate that all toads from three mentioned species have 2n=22 chromosomes. These chromosomes are arranged into two groups. First group has six large chromosomes and the second group is composed of five small chromosomes. These chromosomes are metacentric or submetacentric. The number of submetacentric chromosomes is different in three mentioned species of B. viridis complex. Neither sexual heteromorphism, nor secondary constriction was observed in any pairs of chromosomes.

  11. A physiological study of integument secretions in the marine polychaete Eulalia viridis and their potential biotechnological value.

    Directory of Open Access Journals (Sweden)

    Ana Patrícia Rodrigo


    Full Text Available There is a growing interest in marine bioproducts, especially in those with life improving potential to humans. Marine invertebrates, in particular, possess particular interest due to their high diversity, abundance and ecological importance. However, the physiology of such a wide and diverse group of organisms is far from understood. Marine annelids, in particular (Class Polychaeta, are of especial interest, in large part owing to their ecological representativity and easy handling. Still only few studies have been focusing on physiological traits of the polychaeta that may relate to the production of bioproducts of potential biotechnological applications. The secretion of substances by polychaetes is acknowledged to relate primarily with locomotion and feeding, but also thought to have an important role in egg protection, prevention against infection and even as defence mechanisms against possible predators. As such, the present work aims at identifying, isolating and analysing the nature of integumentary secretions of E. viridis, a common intertidal worm of rocky shores. Histological analyses revealed a more complex microanatomy of the skin than it could be anticipated. Several cell types were identified in the integument, each bearing different functions such as structural support, pigmentation and sensorial, to which is added secretion as one of the most important roles. Due to the great complexity of the integument, the identification of the chemical nature of all types of secretions is particularly challenging. However, more detailed histochemical analyses and electron microscopy enabled the identification of different secretory cells and their chemical nature and role. The analyses was complemented by protein isolation from mucous and homogenates trough SDS-PAGE. Extracts revealed, for instance, that peptidic substances produced by the skin are potentially biocidal, as assessed through the Microtox Assay. Overall, the results enhance the

  12. Mapping lipid and detergent molecules at the surface of membrane proteins. (United States)

    Cogdell, Richard J; Gardiner, Alastair T; Roszak, Aleksander W; Stončius, Sigitas; Kočovský, Pavel; Isaacs, Neil W


    Electron-density maps for the crystal structures of membrane proteins often show features suggesting binding of lipids and/or detergent molecules on the hydrophobic surface, but usually it is difficult to identify the bound molecules. In our studies, heavy-atom-labelled phospholipids and detergents have been used to unequivocally identify these binding sites at the surfaces of test membrane proteins, the reaction centres from Rhodobacter sphaeroides and Blastochloris viridis. The generality of this method is discussed in the present article.


    Institute of Scientific and Technical Information of China (English)

    Chee Kong Yap; Ahmad Ismail; Abdul Rahim Ismail; Soon Guan Tan


    The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites ( 10 from the west and 2 from the east coastal waters) of Peninsular Malaysia. All samples showed that the levels of Cd, Pb and Zn were generally higher in the gill than those in the remaining soft tissues. These results could be due to the fact that gills are the first organ of metal accumulation and larger surface area with mucus sheets in the organ. Since the mussel gill is a better accumulator of Cd, Pb and Zn of ambient seawater than remaining soft tissue, it is a potential indicator of ambient levels of dissolved metals in the ambient seawater. However, further validations based on laboratory conditions are needed.

  14. Effects of the invasive polychaete, Marenzelleria viridis, on the fate of sediment associated pollutants – a microcosm study with 14C-labelled pyrene

    DEFF Research Database (Denmark)

    Banta, Gary Thomas; Hedman, Jenny Elisabet

    on the fate of deeply buried sediment-associated pollutants in the historically polluted Baltic Sea. We report here the results of an experimental microcosm study examining the fate of 14C radiolabelled pyrene (a 4-ring PAH) in sediment microcosms with and without Marenzelleria viridis. We also investigated...... the impact of depositing labile organic matter (seston) on the sediment surface. Worms clearly enhanced the release of pyrene and degradation metabolites from the sediment to the overlying water in all cases, mostly due to the initial flushing of sediments during burrow establishment. Surprisingly......, there was no clear effect of worms on the mineralization of pyrene to CO2, where a complicated interaction between bioturbation and the presence of labile organic matter was observed. Furthermore, the ultimate fate of the increased release of sediment-associated pyrene and its metabolites to the water is unknown....

  15. Habitat degradation correlates with tolerance to climate-change related stressors in the green mussel Perna viridis from West Java, Indonesia. (United States)

    Wendling, Carolin Charlotte; Huhn, Mareike; Ayu, Nurina; Bachtiar, Ramadian; von Juterzenka, Karen; Lenz, Mark


    It is unclear whether habitat degradation correlates with tolerance of marine invertebrates to abiotic stress. We therefore tested whether resistance to climate change-related stressors differs between populations of the green mussel Perna viridis from a heavily impacted and a mostly pristine site in West Java, Indonesia. In laboratory experiments, we compared their oxygen consumption and mortality under lowered salinity (-13 and -18 units, both responses), hypoxia (0.5 mg/l, mortality only) and thermal stress (+7 °C, mortality only). Mussels from the eutrophied and polluted Jakarta Bay showed a significantly smaller deviation from their normal oxygen consumption and higher survival rates when stressed than their conspecifics from the unaffected Lada Bay. This shows that human induced habitat degradation correlates with mussel tolerance to environmental stress. We discuss possible mechanisms - e.g. the selection of tolerant genotypes or habitat-specific differences in the nutritional status of the mussels - that could explain our observation.

  16. Toxic effects of male Perna viridis gonad exposed to BaP, DDT and their mixture: A metabolomic and proteomic study of the underlying mechanism. (United States)

    Song, Qinqin; Zheng, Pengfei; Qiu, Liguo; Jiang, Xiu; Zhao, Hongwei; Zhou, Hailong; Han, Qian; Diao, Xiaoping


    Benzo(a)pyrene and dichlorodiphenyltrichloroethane are typical persistent organic pollutants, and also the widespread environmental estrogens with known toxicity towards green mussels Perna viridis. In this study, the toxicological effects of BaP and DDT and their mixture were assessed in green mussel gonads using proteomic and metabolomic approaches. Metabolomics by NMR spectroscopy revealed that BaP did not show obvious metabolite changes in the gonad of male green mussel. DDT mainly caused some disturbance of osmotic regulation and energy metabolism by changing BCAAs, alanine, threonine, arginine, etc., unknown metabolite (3.53 ppm), glycine, homarine and ATP at different levels. However, the mixture of BaP and DDT mainly caused some disturbance in osmotic regulation and energy metabolism by differentially altering branched chain amino acids, glutamate, alanine, arginine, unknown metabolite (3.53 ppm), glycine, 4-aminobutyrate, dimethylglycine, homarine and ATP. The results suggest that DDT alone may cause most of metabolites changes in the mixture exposed male mussel gonad, and the results also show that the male P. viridis gonad was more sensitive to DDT than BaP exposures. Proteomic study showed that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced signal transduction, oxidative stress, spermatogenesis, etc. in the male green mussel gonad; whereas DDT exposure altered proteins that were associated with signal transduction, oxidative stress, cytoskeleton and cell structure, cellular organization, energy metabolism, etc. However, the mixture of BaP and DDT affected proteins related to cytoskeleton and cell structure, oxidative stress, cellular organization, etc. This research demonstrated that metabolomic and proteomic approaches could better elucidate the underlying mechanism of environmental pollutants gonad toxicity.

  17. Characterization of a glutamine synthetase gene DvGS2 from Dunaliella viridis and biochemical identification of DvGS2-transgenic Arabidopsis thaliana. (United States)

    Zhu, Chenguang; Fan, Qianlan; Wang, Wei; Shen, Chunlei; Meng, Xiangzong; Tang, Yuanping; Mei, Bing; Xu, Zhengkai; Song, Rentao


    The salt-tolerant green alga Dunaliella has remarkable capability to survive in some extreme environments such as nitrogen starvation, which makes Dunaliella be a proper model for mining novel genes on nitrogen uptake or assimilation. In this study, a glutamine synthetase (GS) gene DvGS2 with amino acid identity of 72% to other homologous GS proteins, was isolated and characterized from Dunaliella viridis. Phylogenetic comparison with other GSs revealed that DvGS2 occupied an independent phylogenetic position. Expressional analysis in D. viridis cells under nitrogen starvation confirmed that DvGS2 increased its mRNA level in 12h. Subcellular localization study and functional analysis in a GS-deficient Escherichia coli mutant proved that DvGS2 was a chloroplastic and functional GS enzyme. In order to investigate the potential application of DvGS2 in higher plants, the transgenic studies of DvGS2 in Arabidopsis thaliana were carried out. Results showed that the transgenic lines expressed the DvGS2 gene and demonstrated obviously enhanced root length (29%), fresh weight (40%-48% at two concentrations of nitrate supplies), stem length (21%), leaf size (39%) and silique number (44%) in contrast with the wild-type Arabidopsis. Furthermore, the transgenic lines had higher total nitrogen content (35%-43%), total GS activity (39%-45%) and soluble protein concentration (23%-24%) than the wild type. These results indicated that the overexpression of DvGS2 in A. thaliana resulted in higher biomass and the improvement of the host's nitrogen use efficiency.

  18. Tolerancia a la anoxia y defensas antioxidantes en el mejillón verde Perna viridis (Linneus, 1758 bajo exposición aguda al cadmio

    Directory of Open Access Journals (Sweden)

    Edgar Zapata-Vívenes


    Full Text Available Se estimó la sobrevivencia a la anoxia del mejillón verde Perna viridis después de siete días de exposición a 50 μg L-1 de cadmio (Cd, seguido de un período de recuperación en el mar durante 21 días. En la glándula digestiva de los organismos experimentales se determinó los niveles de Cd acumulados, y marcadores de estrés oxidativo tales como: metalotioneínas (MT, glutatión reducido (GSH, peroxidación lipídica (TBARS y las actividades de las enzimas catalasa (CAT, glutatión reductasa (GR y glutatión-S-transferasa (GST. Los organismos expuestos a Cd mostraron una menor tolerancia al tratamiento anóxico, sin embargo una vez recuperados en el mar presentaron valores de sobrevivencia relativamente mayores en comparación a sus controles. Los organismos expuestos a Cd revelaron un incremento en la concentración de MT y la actividad de CAT, correlacionado al ingreso corporal de Cd. Los organismos transplantados al mar mostraron una disminución del metal acumulado, manteniendo niveles de MT incrementados. Los mejillones tratados y controles no exhibieron diferencias significativas en los marcadores de estrés oxidativo determinados (TBARS, GSH, GR y GST. El Cd acumulado posiblemente afectó algunas estrategias bioquímicas relacionadas con la tolerancia a la anoxia de P. viridis. Sin embargo, los altos niveles de MT en organismos pre-expuestos y posteriormente recuperados, podría condicionar la protección contra la toxicidad del Cd e indirectamente una mayor tolerancia a la anoxia.

  19. Specific binding of a Pop6/Pop7 heterodimer to the P3 stem of the yeast RNase MRP and RNase P RNAs. (United States)

    Perederina, Anna; Esakova, Olga; Koc, Hasan; Schmitt, Mark E; Krasilnikov, Andrey S


    Pop6 and Pop7 are protein subunits of Saccharomyces cerevisiae RNase MRP and RNase P. Here we show that bacterially expressed Pop6 and Pop7 form a soluble heterodimer that binds the RNA components of both RNase MRP and RNase P. Footprint analysis of the interaction between the Pop6/7 heterodimer and the RNase MRP RNA, combined with gel mobility assays, demonstrates that the Pop6/7 complex binds to a conserved region of the P3 domain. Binding of these proteins to the MRP RNA leads to local rearrangement in the structure of the P3 loop and suggests that direct interaction of the Pop6/7 complex with the P3 domain of the RNA components of RNases MRP and P may mediate binding of other protein components. These results suggest a role for a key element in the RNase MRP and RNase P RNAs in protein binding, and demonstrate the feasibility of directly studying RNA-protein interactions in the eukaryotic RNases MRP and P complexes.

  20. The isopenicillin N acyltransferases of Aspergillus nidulans and Penicillium chrysogenum differ in their ability to maintain the 40-kDa alphabeta heterodimer in an undissociated form. (United States)

    Fernández, Francisco J; Cardoza, Rosa E; Montenegro, Eduardo; Velasco, Javier; Gutiérrez, Santiago; Martín, Juan F


    The isopenicillin N acyltransferases (IATs) of Aspergillus nidulans and Penicillium chrysogenum differed in their ability to maintain the 40-kDa proacyltransferase alphabeta heterodimer in an undissociated form. The native A. nidulans IAT exhibited a molecular mass of 40 kDa by gel filtration. The P. chrysogenum IAT showed a molecular mass of 29 kDa by gel filtration (corresponding to the beta subunit of the enzyme) but the undissociated 40-kDa heterodimer was never observed even in crude extracts. Heterologous expression experiments showed that the chromatographic behaviour of IAT was determined by the source of the penDE gene used in the expression experiments and not by the host itself. When the penDE gene of A. nidulans was expressed in P. chrysogenum npe6 and npe8 or in Acremonium chrysogenum, the IAT formed had a molecular mass of 40 kDa. On the other hand, when the penDE gene originating from P. chrysogenum was expressed in A. chrysogenum, the active IAT had a molecular mass of 29 kDa. The intronless form of the penDE gene cloned from an A. nidulans cDNA library and overexpressed in Escherichia coli formed the enzymatically active 40-kDa proIAT, which was not self-processed as shown by immunoblotting with antibodies to IAT. This 40-kDa protein remained unprocessed even when treated with A. nidulans crude extract. In contrast, the P. chrysogenum penDE intronless gene cloned from a cDNA library was expressed in E. coli, and the IAT was self-processed efficiently into its alpha (29 kDa) and beta (11 kDa) subunits. It is concluded that P. chrysogenum and A. nidulans differ in their ability to self-process their respective proIAT protein and to maintain the alpha and beta subunits as an undissociated heterodimer, probably because of the amino-acid sequence differences in the proIAT which affect the autocatalytic activity.

  1. Native Folding of a Recombinant gpE1/gpE2 Heterodimer Vaccine Antigen from a Precursor Protein Fused with Fc IgG. (United States)

    Logan, Michael; Law, John; Wong, Jason Alexander Ji-Xhin; Hockman, Darren; Landi, Amir; Chen, Chao; Crawford, Kevin; Kundu, Juthika; Baldwin, Lesley; Johnson, Janelle; Dahiya, Anita; LaChance, Gerald; Marcotrigiano, Joseph; Law, Mansun; Foung, Steven; Tyrrell, Lorne; Houghton, Michael


    A recombinant strain HCV1 (hepatitis C virus [HCV] genotype 1a) gpE1/gpE2 (E1E2) vaccine candidate was previously shown by our group to protect chimpanzees and generate broad cross-neutralizing antibodies in animals and humans. In addition, recent independent studies have highlighted the importance of conserved neutralizing epitopes in HCV vaccine development that map to antigenic clusters in E2 or the E1E2 heterodimer. E1E2 can be purified using Galanthis nivalis lectin agarose (GNA), but this technique is suboptimal for global production. Our goal was to investigate a high-affinity and scalable method for isolating E1E2. We generated an Fc tag-derived (Fc-d) E1E2 that was selectively captured by protein G Sepharose, with the tag being removed subsequently using PreScission protease. Surprisingly, despite the presence of the large Fc tag, Fc-d E1E2 formed heterodimers similar to those formed by GNA-purified wild-type (WT) E1E2 and exhibited nearly identical binding profiles to HCV monoclonal antibodies that target conserved neutralizing epitopes in E2 (HC33.4, HC84.26, and AR3B) and the E1E2 heterodimer (AR4A and AR5A). Antisera from immunized mice showed that Fc-d E1E2 elicited anti-E2 antibody titers and neutralization of HCV pseudotype viruses similar to those with WT E1E2. Competition enzyme-linked immunosorbent assays (ELISAs) showed that antisera from immunized mice inhibited monoclonal antibody binding to neutralizing epitopes. Antisera from Fc-d E1E2-immunized mice exhibited stronger competition for AR3B and AR5A than the WT, whereas the levels of competition for HC84.26 and AR4A were similar. We anticipate that Fc-d E1E2 will provide a scalable purification and manufacturing process using protein A/G-based chromatography.


    Institute of Scientific and Technical Information of China (English)

    张爱武; 罗素琴; 刘乐乐; 吴宁远; 王来兵; 于姝燕; 张国萍


    Objective: To extract total tannin from Setaria viridis (L. ) Beaux, ripe fruits and deter mination the content of total tannin. Methods: It was adopted the optimum ultrasonic extraction tech nique to extract the total tannin from Setaira viridis (L. ) Beauv. Ripe fruits. Compleximetry was applied to determine the content of total tannin. Results: The content of total tannin was 0.4650%. Conclu sion :Ultrasonic extraction technique is simple and rapid,Content determination of complexometric titra tion method is safe and reliable. The method was available for extraction and content determination of total tannin from Setaria viridis (L. ) Beauv. Ripe fruits.%目的:从狗尾草果实中提取总鞣质并测定其含量.方法:采用超声波法提取狗尾革果实的总鞣质,用络合滴定法测定其总鞣质的含量.结果:狗尾草果实总鞣质的含量为0.4650%.结论:采用超声法提取操作程序简便、迅速,络合滴定法含量测定方法安全可靠,准确度和精密度较高,可用于狗尾草果实中总鞣质的提取及含量测定.

  3. Synthesis and anti-HIV activity of some [Nucleoside Reverse Transcriptase Inhibitor]-C5'-linker-[Integrase Inhibitor] heterodimers as inhibitors of HIV replication. (United States)

    Sugeac, Elena; Fossey, Christine; Ladurée, Daniel; Schmidt, Sylvie; Laumond, Geraldine; Aubertin, Anne-Marie


    Selected for their expected ability to inhibit HIV replication, a series of eight heterodimers containing a Nucleoside Reverse Transcriptase Inhibitor (NRTI) and an Integrase Inhibitor (INI), bound by a linker, were designed and synthesized. For the NRTIs, d4U, d2U and d4T were chosen. For the INIs, 4-[1-(4-fluorobenzyl)-1H-pyrrol-2-yl]-2,4-dioxobutyric acid (6) and 4-(3,5-dibenzyloxyphenyl)-2,4-dioxobutyric acid (9) (belonging to the beta-diketo acids class) were chosen. The conjugation of the two different inhibitors (NRTI and INI) was performed using an amino acid (glycine or beta-alanine) as a cleavable linker.

  4. Conicasterol E, a small heterodimer partner sparing farnesoid X receptor modulator endowed with a pregnane X receptor agonistic activity, from the marine sponge Theonella swinhoei. (United States)

    Sepe, Valentina; Ummarino, Raffaella; D'Auria, Maria Valeria; Chini, Maria Giovanna; Bifulco, Giuseppe; Renga, Barbara; D'Amore, Claudio; Debitus, Cécile; Fiorucci, Stefano; Zampella, Angela


    We report the isolation and pharmacological characterization of conicasterol E isolated from the marine sponge Theonella swinhoei. Pharmacological characterization of this steroid in comparison to CDCA, a natural FXR ligand, and 6-ECDCA, a synthetic FXR agonist generated by an improved synthetic strategy, and rifaximin, a potent PXR agonist, demonstrated that conicasterol E is an FXR modulator endowed with PXR agonistic activity. Conicasterol E induces the expression of genes involved in bile acids detoxification without effect on the expression of small heterodimer partner (SHP), thus sparing the expression of genes involved in bile acids biosynthesis. The relative positioning in the ligand binding domain of FXR, explored through docking calculations, demonstrated a different spatial arrangement for conicasterol E and pointed to the presence of simultaneous and efficient interactions with the receptor. In summary, conicasterol E represents a FXR modulator and PXR agonist that might hold utility in treatment of liver disorders.

  5. [Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad]. (United States)

    Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel


    The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low

  6. Changes in growth, carbon and nitrogen enzyme activity and mRNA accumulation in the halophilic microalga Dunaliella viridis in response to NaCl stress (United States)

    Wang, Dongmei; Wang, Weiwei; Xu, Nianjun; Sun, Xue


    Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaCl stress on the growth, activity and mRNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the most rapid growth was observed at 1.00 mol L-1 NaCl, followed by 2.00 mol L-1 NaCl. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00 mol L-1 NaCl, decreasing to 37.33% and 26.39% of those values, respectively, in the presence of 3.00 mol L-1 NaCl, respectively. However, the highest extracellular carbonic anhydrase (CA) activity was measured in the presence of 2.00 mol L-1 NaCl, followed by 1.00 mol L-1 NaCl. Different from the two carbon enzymes, nitrate reductase (NR) activity showed a slight change under different NaCl concentrations. At the transcriptional level, the mRNAs of Rubisco large subunit ( rbcL), and small subunit ( rbcS), attained their highest abundances in the presence of 1.00 and 2.00 mol L-1 NaCl, respectively. The CA mRNA accumulation was induced from 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the NR mRNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaCl stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaCl in D. viridis.

  7. Theoretical studies on the influence of molecular interactions on the mechanism of electron transfer in photosynthetic reaction center of Rps. viridis

    Institute of Scientific and Technical Information of China (English)

    徐红; 张汝波; 屈正旺; 张兴康; 张启元


    Based on the QM/MM optimized X-ray crystal structure of the photosynthetic reaction center (PRC) of purple bacteria Rhodopseudomonas (Rps.) viridis, quantum chemistry density functional method (DFT, B3LYP/6-31G) has been performed to study the interactions between the pigment molecules and either the surrounded amino acid residues or water molecules that are either axially coordinated or hydrogen bonded with the pigment molecules, leading to an explanation of the mechanism of the primary electron-transfer (ET) reactions in the PRC. Results show that the axial coordination of amino acid residues greatly raises the ELUMO of pigment molecules and it is important for the possibility of ET to take place. Different hydrogen bonds between amino acid residues, water molecules and pigment molecules decrease the ELUMO of the pigment molecules to different extents. It is crucial for the ET taking place from excited P along L branch and sustains that the ET is a one-step reaction without through accessory bacteriochlorophyll (ABChl b). It is insufficient to treat the whole protein surrounding as a homogeneous dielectric medium.

  8. Toxicological effects of benzo(a)pyrene, DDT and their mixture on the green mussel Perna viridis revealed by proteomic and metabolomic approaches. (United States)

    Song, Qinqin; Chen, Hao; Li, Yuhu; Zhou, Hailong; Han, Qian; Diao, Xiaoping


    Benzo(a)pyrene (BaP) and dichlorodiphenyltrichloroethane (DDT) are persistent organic pollutants and environmental estrogens (EEs) with known toxicity towards the green mussel, Perna viridis. In this study, the toxic effects of BaP (10 µg/L) and DDT (10 µg/L) and their mixture were assessed in green mussel gills with proteomic and metabolomic approaches. Metabolic responses indicated that BaP mainly caused disturbance in osmotic regulation by significantly decrease in branched chain amino acids, dimethylamine and dimethylglycine in gills of male green mussels after exposure for 7 days. DDT mainly caused disturbance in osmotic regulation and energy metabolism by differential alteration of betaine, dimethylamine, dimethylglycine, amino acids, and succinate in gills of male green mussels. However, the mixture of BaP and DDT didn't show obvious metabolite changes. Proteomic analysis showed different protein expression profiles between different treatment groups, which demonstrated that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced cell apoptosis, disturbance in protein digestion and energy metabolism in gills of green mussels, whereas DDT exposure altered proteins that were associated with oxidative stress, cytoskeleton and cell structure, protein digestion and energy metabolism. However, the mixture of BaP and DDT affected proteins related to the oxidative stress, cytoskeleton and cell structure, protein biosynthesis and modification, energy metabolism, growth and apoptosis.

  9. Phenotypic Plasticity of Life History Characteristics:Quantitative Analysis of Delayed Reproduction of Green Foxtail (Setaria viridis) in the Songnen Plain of China

    Institute of Scientific and Technical Information of China (English)

    Hai-Yan Li; Yun-Fei Yang


    Green foxtail (Setaria viridis L,) is a common weed species in temperate regions. Research on the effect of delayed reproduction on the phenotypic plasticity and regularity of the vegetative and reproductive growth is of vital significance for understanding population regulation and control of the weed in the growing season, Green foxtail seeds were sown every 10 days from 25 June to 24 August of 2004. The growth and production metrics were measured via harvesting tufts and statistical analysis was carried out. The results showed that the reproductive tillers, seed number, seed biomass and one thousand-seed weight of plants at the first sowing (25 June) approximately increased 28.8, 7827.0, 1104.0 and 12.3 times compared with that at the last sowing (24 August), respectively. Total tillers, reproductive tillers and height increased linearly as the reproductive period delayed, however, biomass increased exponentially. Quadratic equations best explained the relationships between the delayed reproductive period and seed number, Inflorescence length, one thousand-seed weight, seed biomass. Based on the quantity and quality of seed production, weeding young seedlings emerging before July can be the most effective weed-control strategy in the Songnen Plain.

  10. Computed tomography of the lung of healthy snakes of the species Python regius, Boa constrictor, Python reticulatus, Morelia viridis, Epicrates cenchria, and Morelia spilota. (United States)

    Pees, Michael; Kiefer, Ingmar; Thielebein, Jens; Oechtering, Gerhard; Krautwald-Junghanns, Maria-Elisabeth


    Thirty-nine healthy boid snakes representing six different species (Python regius, Boa constrictor, Python reticulatus, Morelia viridis, Epicrates cenchria, and Morelia spilota) were examined using computed tomography (CT) to characterize the normal appearance of the respiratory tissue. Assessment was done subjectively and densitometry was performed using a defined protocol. The length of the right lung was calculated to be 11.1% of the body length, without a significant difference between species. The length of the left lung in proportion to the right was dependent on the species examined. The most developed left lung was in P. regius (81.2%), whereas in B. constrictor, the left lung was vestigial or absent (24.7%). A median attenuation of -814.6 HU and a variability of 45.9 HU were calculated for all species with no significant difference between species. Within the species, a significantly higher attenuation was found for P. regius in the dorsal and cranial aspect of the lung compared with the ventral and caudal part. In B. constrictor, the reduced left lung was significantly hyperattenuating compared with the right lung. Results of this study emphasize the value of CT and provide basic reference data for assessment of the snake lung in these species. Veterinary Radiology &

  11. Differential proteomic responses in hepatopancreas and adductor muscles of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Priscilla T.Y. [Swire Institute of Marine Science and School of Biological Sciences, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong); Wang Yu [Department of Pharmacology and Pharmacy, University of Hong Kong, Sassoon Road, Hong Kong (Hong Kong); Mak, Sarah S.T.; Ng, W.C. [Swire Institute of Marine Science and School of Biological Sciences, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong); Leung, Kenneth M.Y., E-mail: [Swire Institute of Marine Science and School of Biological Sciences, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong)


    This study aimed to reveal the proteomic responses in the hepatopancreas and adductor muscle of a common biomonitor, Perna viridis after 14-day exposure to two model chemicals, cadmium (Cd; a toxic metal) and hydrogen peroxide (H{sub 2}O{sub 2}; a pro-oxidant), using two-dimensional gel electrophoresis coupled with multivariate statistical analyses. Unique sets of tissue-specific protein expression signatures were revealed corresponding to the two treatment groups. In the hepatopancreas, 15 and 2 spots responded to Cd and H{sub 2}O{sub 2} treatments respectively. 6 and 7 spots were differentially expressed in the adductor muscle for Cd and H{sub 2}O{sub 2} treatments, respectively. 15 differentially expressed spots were successfully identified by MALDI-TOF/TOF MS analysis. These proteins are involved in glycolysis, amino acid metabolism, energy homeostasis, oxidative stress response, redox homeostasis and protein folding, heat-shock response, and muscle contraction modulation. This is the first time, to have demonstrated that Cd exposure not only leads to substantial oxidative stress but also results in endoplasmic reticulum stress in hepatopancreas of the mussel. Such notable stress responses may be attributable to high Cd accumulation in this tissue. Our results suggested that investigations on these stress-associated protein changes could be used as a new and complementary approach in pollution monitoring by this popular biomonitor species.

  12. Heterodimers of tyrosylprotein sulfotransferases suggest existence of a higher organization level of transferases in the membrane of the trans-Golgi apparatus. (United States)

    Hartmann-Fatu, Cristina; Trusch, Franziska; Moll, Carina N; Michin, Irina; Hassinen, Antti; Kellokumpu, Sakari; Bayer, Peter


    Tyrosine sulfation of proteins is an important post-translational modification shown to play a role in many membrane-associated or extracellular processes such as virus entry, blood clotting, antibody-mediated immune response, inflammation and egg fecundation. The sole two human enzymes that transfer sulfate moieties from 3'-phospho-adenosine-5'-phospho-sulfate onto tyrosine residues, TPST1 and TPST2, are anchored to the membranes of the trans-Golgi compartment with the catalytic domain oriented to the lumen. In contrast to the relatively well studied organization of medial Golgi enzymes, the organization of trans-Golgi transferases remains elusive. Although tyrosylprotein sulfotransferases are known to exist as homodimers in the Golgi membranes, this organization level may represent only a small piece of a puzzle that is linked to the entire picture. Here we report the formation of TPST1/TPST2 heterodimers and a novel interaction between either TPST1 or TPST2 and the α-2,6-sialyltransferase, indicating a higher organization level of tyrosylprotein sulfotransferases that may serve for substrate selectivity and/or effective organization of multiple post-translational modification of proteins.

  13. Small heterodimer partner 1 directly interacts with NS5A viral protein and has a key role in HCV related liver cell transformation. (United States)

    Conti, Beatrice; Porcu, Cristiana; Viscomi, Carmela; Minutolo, Antonella; Costantini, Susan; Corazzari, Marco; Iannucci, Gino; Barbaro, Barbara; Balsano, Clara


    HCV life cycle is strictly correlated with the hepatocyte lipid metabolism; moreover, the progression of HCV chronic hepatitis is accelerated by the presence of liver steatosis. Among the steatogenic genes deregulated during the HCV infection one of the most attractive is the Small Heterodimer Protein 1 (SHP1; NR0B2), that is involved in a remarkable number of metabolic functions. HCV NS5A is an essential and integral component of the HCV membranous-web replicon complex (RC) and plays an essential role to transfer the viral genome from the RCs to the surface of the lipid droplets (LDs) that, in turn, play a key function during HCV life cycle.With the help of a HCV infection model, we demonstrate a functional interaction between SHP1 and HCV NS5A protein. SHP1 silencing (siSHP1) reversed the pro-oncogenic effects of HCV infection, inducing a significant decrease in liver lipid accumulation and in NS5A protein expression. Moreover, siSHP1 causes a strong modulation of some genes involved in HCV-related EMT, such as: HNF4, a central regulators of hepatocyte differentiation, E-Cadherin, SNAILs.Our data suggest that SHP1 results not only to be strictly connected to the pathogenesis of HCV-related liver steatosis, but also to its progression towards the liver transformation.

  14. Time-resolved FRET binding assay to investigate hetero-oligomer binding properties: proof of concept with dopamine D1/D3 heterodimer. (United States)

    Hounsou, Candide; Margathe, Jean-François; Oueslati, Nadia; Belhocine, Abderazak; Dupuis, Elodie; Thomas, Cécile; Mann, André; Ilien, Brigitte; Rognan, Didier; Trinquet, Eric; Hibert, Marcel; Pin, Jean-Philippe; Bonnet, Dominique; Durroux, Thierry


    G protein-coupled receptors (GPCRs) have been described to form hetero-oligomers. The importance of these complexes in physiology and pathology is considered crucial, and heterodimers represent promising new targets to discover innovative therapeutics. However, there is a lack of binding assays to allow the evaluation of ligand affinity for GPCR hetero-oligomers. Using dopamine receptors and more specifically the D1 and D3 receptors as GPCR models, we developed a new time-resolved FRET (TR-FRET) based assay to determine ligand affinity for the D1/D3 heteromer. Based on the high-resolution structure of the dopamine D3 receptor (D3R), six fluorescent probes derived from a known D3R partial agonist (BP 897) were designed, synthesized and evaluated as high affinity and selective ligands for the D3/D2 receptors, and for other dopamine receptor subtypes. The highest affinity ligand 21 was then employed in the development of the D1/D3 heteromer assay. The TR-FRET was monitored between a fluorescent tag donor carried by the D1 receptor (D1R) and a fluorescent acceptor D3R ligand 21. The newly reported assay, easy to implement on other G protein-coupled receptors, constitutes an attractive strategy to screen for heteromer ligands.

  15. Interaction of the Ku heterodimer with the DNA ligase IV/Xrcc4 complex and its regulation by DNA-PK. (United States)

    Costantini, Silvia; Woodbine, Lisa; Andreoli, Lucia; Jeggo, Penny A; Vindigni, Alessandro


    DNA non-homologous end-joining (NHEJ) is a major mechanism for repairing DNA double-stranded (ds) breaks in mammalian cells. Here, we characterize the interaction between two key components of the NHEJ machinery, the Ku heterodimer and the DNA ligase IV/Xrcc4 complex. Our results demonstrate that Ku interacts with DNA ligase IV via its tandem BRCT domain and that this interaction is enhanced in the presence of Xrcc4 and dsDNA. Moreover, residues 644-748 of DNA ligase IV encompassing the first BRCT motif are necessary for binding. We show that Ku needs to be in its heterodimeric form to bind DNA ligase IV and that the C-terminal tail of Ku80, which mediates binding to DNA-PKcs, is dispensable for DNA ligase IV recognition. Although the interaction between Ku and DNA ligase IV/Xrcc4 occurs in the absence of DNA-PKcs, the presence of the catalytic subunit of DNA-PK kinase enhances complex formation. Previous studies have shown that DNA-PK kinase activity causes disassembly of DNA-PKcs from Ku at the DNA end. Here, we show that DNA-PK kinase activity also results in disassembly of the Ku/DNA ligase IV/Xrcc4 complex. Collectively, our findings provide novel information on the protein-protein interactions that regulate NHEJ in cells.

  16. Can the byssus of green-lipped mussel Perna viridis (Linnaeus) from the west coast of Peninsular Malaysia be a biomonitoring organ for Cd, Pb and Zn? Field and laboratory studies. (United States)

    Yap, C K; Ismail, A; Tan, S G


    Concentrations of cadmium (Cd), lead (Pb) and zinc (Zn) in total soft tissues (ST) and byssus (BYS) of the green-lipped mussel Perna viridis from 11 different geographical locations off the west coast of Peninsular Malaysia were determined. The metal concentrations distributed between the BYS and ST were compared. The results of this study indicated that higher levels of Cd (1.31 microg/g), Pb (38.49 microg/g) and Zn (206.52 microg/g) were accumulated in the BYS than in the total ST (Cd: 0.29 microg/g; Pb: 8.27 microg/g; Zn: 102.6 microg/g). Semi-static and short period controlled laboratory experiments were also conducted for the accumulation and depuration of Cd, Pb and Zn in the total ST and BYS of P. viridis. The ratios (BYS/ST) for Pb and Cd from the laboratory experiments showed that the total ST accumulated more metals than the BYS. Therefore, these laboratory results disagreed with those found for the field samples. However, the laboratory results for the Zn ratio (BYS/ST) agreed with those of the field samples. It was evident that when compared to the ST, the BYS was a more sensitive biomonitoring organ for Zn while it could be a complementary organ for Cd and Pb in the total ST. Since total ST of P. viridis had been reported to have regulative mechanism for Zn, its BYS can be used as a biomonitoring organ for the identification of coastal areas exposed to Zn pollution.

  17. Identification of fruit volatiles from green hawthorn (Crataegus viridis) and blueberry hawthorn (Crataegus brachyacantha) host plants attractive to different phenotypes of Rhagoletis pomonella flies in the southern United States. (United States)

    Cha, Dong H; Powell, Thomas H Q; Feder, Jeffrey L; Linn, Charles E


    The apple maggot fly, Rhagoletis pomonella, infests several hawthorn species in the southern USA. In a companion paper, we showed that R. pomonella flies infesting two different mayhaw species (Crataegus opaca and C. aestivalis) can discriminate between volatile blends developed for each host fruit, and that these blends are different from previously constructed blends for northern fly populations that infest domestic apple (Malus domestica), downy hawthorn (Crataegus mollis), and flowering dogwood (Cornus florida). Here, we show by using coupled gas chromatography and electroantennographic detection (GC-EAD), gas chromatography with mass spectrometry (GC-MS), and flight tunnel bioassays, that two additional southern hawthorn fly populations infesting C. viridis (green hawthorn) and C. brachyacantha (blueberry hawthorn) also can discriminate between volatile blends for each host fruit type. A 9-component blend was developed for C. viridis (3-methylbutan-1-ol [5%], butyl butanoate [19.5%], propyl hexanoate [1.5%], butyl hexanoate [24%], hexyl butanoate [24%], pentyl hexanoate [2.5%], 1-octen-3-ol [0.5%], pentyl butanoate [2.5%], and (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) [20.5%]) and an 8-component blend for C. brachyacantha (3-methylbutan-1-ol [0.6%], butyl acetate [50%], pentyl acetate [3.5%], butyl butanoate [9%], butyl hexanoate [16.8%], hexyl butanoate [16.8%], 1-octen-3-ol [0.3%], and pentyl butanoate [3%]). Crataegus viridis and C. brachyacantha-origin flies showed significantly higher levels of upwind oriented flight to their natal blend in flight tunnel assays compared to the alternate, non-natal blend and previously developed northern host plant blends. The presence of DMNT in C. viridis and butyl acetate in C. brachyacantha appeared to be largely responsible for driving the differential response. This sharp behavioral distinction underscores the diversity of odor response phenotypes in the southern USA, points to possible host race formation in these

  18. Componentes bioquímicos de los tejidos de Perna perna y P. viridis (Lineo, 1758) (Bivalvia: Mytilidae), en relación al crecimiento en condiciones de cultivo suspendido


    Acosta, Vanessa; Natera,Yolimar; Lodeiros, César; Freites,Luis; Vásquez,Aléikar


    Se evaluó los cambios ocurridos en carbohidratos, proteínas y lípidos de la glándula digestiva, músculo y lóbulos gonadales de los mejillones Perna perna y P. viridis bajo condiciones de cultivo suspendido en el Golfo de Cariaco, Venezuela. Paralelamente, se llevaron registros de la condición reproductiva de ambas especies y de temperatura, clorofila a y seston. Los resultados muestraron que en los tejidos analizados de ambas especies, los lóbulos gonadales presentaron las mayores variaciones...

  19. Density, recruitment and growth performance of Asian green mussel (Perna viridis in Marudu Bay, Northeast Malaysian Borneo, three years after a massive mortality event

    Directory of Open Access Journals (Sweden)

    Afizah Mohd Taib


    Full Text Available Density, recruitment and growth performance of Asian green mussel (Perna viridis in a particular coastal marine environment can be affected by many factors, including environmental change, pollution, disease outbreak and massive mortality event. The present study was conducted to determine the density, recruitment and growth performance of farmed Asian green mussel in Marudu Bay, three years after a mass mortality event. The study was carried out for 12 months between April 2013 and March 2014. The length frequency data of 1,308 individuals of green mussel were analyzed using the latest version of the FAO-ICLARM Fish Stock Assessment Tools (FiSAT II. The result showed that the green mussel recruitment in Marudu Bay occurs throughout the year with two major peaks i.e. February and July which coincided with the monsoon seasons. The asymptotic length (L∞, growth coefficient (K and growth performance index (φ’ of the farmed Asian green mussel in Marudu Bay are relatively high at 113.4 mm, 1.7 year-1 and 4.34, respectively. However, despite good culture location, the settlement density of green mussel in the bay was low. We suspected that the low settlement density could be influenced by the ecological effects due to the long term suspension of the culture substrates and the physiochemical properties of the water in Marudu Bay. Nevertheless, chlorophyll-á measurement alone was not able to justify if food scarcity has resulted in high mortality of the farmed Asian green mussel in Marudu Bay.

  20. Influences of dissolved and colloidal organic carbon on the uptake of Ag, Cd, and Cr by the marine mussel Perna viridis. (United States)

    Pan, Jin-Fen; Wang, Wen-Xiong


    The cross-flow ultrafiltration and radiotracer techniques were used to study the influences of natural dissolved organic carbon (DOC) and colloidal organic carbon (COC) on the bioavailability of Ag, Cd, and Cr to the green mussel Perna viridis. We examined the uptake of these metals by the mussels at different concentrations of DOC and COC from different origins (estuarine, coastal, and diatom decomposed). Using the DOC originating from the decomposed diatom (Thalassiosira pseudonana), we demonstrated that Cd and Cr uptake, quantified by the concentration factor (DCF), increased linearly with increasing DOC concentration. There was, however, no consistent influence of natural DOC concentration on the metal uptake when the DOC was obtained from different sources of seawater (coastal and estuarine). The influences of COC on metal bioavailability were metal-specific and dependent on the geochemical properties of colloids and colloid-metal complexation. Cd uptake rate was not influenced by the COC concentrations. Uptake of diatom-decomposed colloidal Cr was enhanced by 3.4x, whereas the uptake of diatom-decomposed colloidal Ag was decreased by 8.2x compared with the uptake of low molecular weight Cr and Ag (<1 kDa). The uptake of diatom-decomposed colloidal Cr and Ag was generally lower than the uptake of metals bound with the same type of colloids for 2 days. Further aging of the colloid-metal binding reduced metal bioavailability to the mussels. In the presence of different sizes of colloidal particles where there was no major binding of colloids with the metals, metal uptake by the mussels was not influenced by different COC concentrations. Overall, our study suggests that although metal dissociation from colloids may be an important step for the uptake of colloidal metals, other mechanisms such as pinocytosis and co-transport may also be involved in the uptake of these metals, especially in aquatic environments with high DOC and COC concentrations.

  1. Neuro-endocrine effects of aqueous extract of Amaranthus viridis (Linn. leaf in male Wistar rat model of cyclophosphamide-induced reproductive toxicity

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    Ayoka Oladele Abiodun


    Full Text Available Cyclophosphamide (CP is a widely used cytotoxic alkylating agent with antitumor and immunosuppressant properties that is associated with various forms of reproductive toxicity. The significance of natural antioxidants of plant origin should be explored, especially in a world with increasing incidence of patients in need of chemotherapy. The neuro-endocrine effects of aqueous extract of Amaranthus viridis (Linn. leaf (AEAVL in Wistar rats with CP-induced reproductive toxicity was determined. Forty rats were used for this study such that graded doses of the extract were administered following CP-induced reproductive toxicity and comparisons were made against control, toxic and standard (vitamin E groups at p < 0.05. The synthetic drugs (CP, 65 mg/kg i.p. for 5 days; Vitamin E, 100 mg/kg p.o. for 30 days as well as the extract (100, 200 and 400 mg/kg p.o. for 30 days were administered to the rats at 0.2 mL/100 g. CP induced reproductive toxicity as evidenced by significantly lowered levels of FSH, LH and testosterone, perturbation of sperm characterization, deleterious disruptions of the antioxidant system as evidenced by decreased levels of GSH as well as elevation of TBARS activity. Histopathological examination showed hemorrhagic lesions with scanty and hypertrophied parenchymal cells in the pituitary while the testis showed ballooned seminiferous tubules with loosed connective tissues and vacuolation of testicular interstitium. These conditions were significantly reversed (p < 0.05 following administration of the graded doses of the extract. It was, therefore, concluded that AEAVL could potentially be a therapeutic choice in patients with CP-induced neuro-endocrine dysfunction and reproductive toxicity.

  2. Amino Acid 72 of Mouse and Human GDF9 Mature Domain Is Responsible for Altered Homodimer Bioactivities but Has Subtle Effects on GDF9:BMP15 Heterodimer Activities1 (United States)

    Peng, Jia; Wigglesworth, Karen; Rangarajan, Adithya; Eppig, John J.; Thompson, Thomas B.; Matzuk, Martin M.


    ABSTRACT Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are oocyte-secreted paralogs of the transforming growth factor beta (TGFbeta) superfamily. In mammals, these two growth factors play critical roles in folliculogenesis. As previously reported, an arginine in the pre-helix loop of GDF5 defines the high binding specificity to its type 1 receptor. Interestingly, bioactive mouse GDF9 and human BMP15 share the conserved arginine in the pre-helix loop, but their low-activity counterparts (mouse BMP15 and human GDF9) have a glycine or a proline instead. To address the question of whether the arginine residue defines the different activities of GDF9 and BMP15 homodimers and their heterodimers in human and mouse, we used site-directed mutagenesis to change the species-specific residues in human and mouse proteins, and examined their activities in our in vitro assays. Although amino acid 72 of mature GDF9 is responsible for altered homodimer bioactivities, neither the corresponding BMP15 amino acid 62 nor the intact pre-helix loop is indispensable for BMP15 homodimer activity. However, amino acid 72 in GDF9 only has only subtle effects on GDF9:BMP15 heterodimer activity. Based on previous studies and our recent findings, we provide hypothetical models to understand the molecular mechanism to define activities of the homodimeric and heterodimeric ligands. The arginine residue in the pre-helix loop of GDF9 homodimer may prevent the inhibition from its pro-domain or directly alter receptor binding, but this residue in GDF9 does not significantly affect the heterodimer activity, because of suggested conformational changes during heterodimer formation. PMID:25253739

  3. The X-Ray Crystal Structure of the Keratin 1-Keratin 10 Helix 2B Heterodimer Reveals Molecular Surface Properties and Biochemical Insights into Human Skin Disease. (United States)

    Bunick, Christopher G; Milstone, Leonard M


    Keratins 1 (K1) and 10 (K10) are the primary keratins expressed in differentiated epidermis. Mutations in K1/K10 are associated with human skin diseases. We determined the crystal structure of the complex between the distal (2B) helices of K1 and K10 to better understand how human keratin structure correlates with function. The 3.3 Å resolution structure confirms many features inferred by previous biochemical analyses, but adds unexpected insights. It demonstrates a parallel, coiled-coil heterodimer with a predominantly hydrophobic intermolecular interface; this heterodimer formed a higher order complex with a second K1-K10-2B heterodimer via a Cys401(K10) disulfide link, although the bond angle is unanticipated. The molecular surface analysis of K1-K10-2B identified several pockets, one adjacent to the disulfide linkage and conserved in K5-K14. The solvent accessible surface area of the K1-K10 structure is 20-25% hydrophobic. The 2B region contains mixed acidic and basic patches proximally (N-terminal), whereas it is largely acidic distally (C-terminal). Mapping of conserved and nonconserved residues between K1-K10 and K5-K14 onto the structure demonstrated the majority of unique residues align along the outer helical ridge. Finally, the structure permitted a fresh analysis of the deleterious effects caused by K1/K10 missense mutations found in patients with phenotypic skin disease.

  4. Modulation of expression of the nuclear receptor NR0B2 (small heterodimer partner 1) and its impact on proliferation of renal carcinoma cells. (United States)

    Prestin, Katharina; Olbert, Maria; Hussner, Janine; Isenegger, Tamara L; Gliesche, Daniel G; Böttcher, Kerstin; Zimmermann, Uwe; Meyer Zu Schwabedissen, Henriette E


    Mammalian nuclear receptors (NRs) are transcription factors regulating the expression of target genes that play an important role in drug metabolism, transport, and cellular signaling pathways. The orphan and structurally unique receptor small heterodimer partner 1 (syn NR0B2) is not only known for its modulation of drug response, but has also been reported to be involved in hepatocellular carcinogenesis. Indeed, previous studies show that NR0B2 is downregulated in human hepatocellular carcinoma, suggesting that NR0B2 acts as a tumor suppressor via inhibition of cellular growth and activation of apoptosis in this tumor entity. The aim of our study was to elucidate whether NR0B2 may also play a role in other tumor entities. Comparing NR0B2 expression in renal cell carcinoma and adjacent nonmalignant transformed tissue revealed significant downregulation in vivo. Additionally, the impact of heterologous expression of NR0B2 on cell cycle progression and proliferation in cells of renal origin was characterized. Monitoring fluorescence intensity of resazurin turnover in RCC-EW cells revealed no significant differences in metabolic activity in the presence of NR0B2. However, there was a significant decrease of cellular proliferation in cells overexpressing this NR, and NR0B2 was more efficient than currently used antiproliferative agents. Furthermore, flow cytometry analysis showed that heterologous overexpression of NR0B2 significantly reduced the amount of cells passing the G1 phase, while on the other hand, more cells in S/G2 phase were detected. Taken together, our data suggest that downregulation of NR0B2 may also play a role in renal cell carcinoma development and progression.

  5. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha activation of CYP7A1 during food restriction and diabetes is still inhibited by small heterodimer partner. (United States)

    Shin, Dong-Ju; Osborne, Timothy F


    Cholesterol 7alpha-hydroxylase (CYP7A1) catalyzes the rate-limiting step in the classic pathway of hepatic bile acid biosynthesis from cholesterol. During fasting and in type I diabetes, elevated levels of peroxisome proliferator-activated receptor gamma-coactivator-1alpha (PGC-1alpha) induce expression of the Cyp7A1 gene and overexpression of PGC-1alpha in hepatoma cells stimulates bile acid synthesis. Using Ad-PGC-1alpha-RNA interference to induce acute disruption of PGC-1alpha in mice, here we show that PGC-1alpha is necessary for fasting-mediated induction of CYP7A1. Co-immunoprecipitation and promoter activation studies reveal that the induction of CYP7A1 is mediated by direct interaction between PGC-1alpha and the AF2 domain of liver receptor homolog-1 (LRH-1). In contrast, the very similar PGC-1beta could not substitute for PGC-1alpha. We also show that transactivation of PGC-1alpha and LRH-1 is repressed by the small heterodimer partner (SHP). Treatment of mice with GW4064, a synthetic agonist for farnesoid X receptor, induced SHP expression and decreased both the recruitment of PGC-1alpha to the Cyp7A1 promoter and the fasting-induced expression of CYP7A1 mRNA. These data suggest that PGC-1alpha is an important co-activator for LRH-1 and that SHP targets the interaction between LRH-1 and PGC-1alpha to inhibit CYP7A1 expression. Overall, these studies provide further evidence for the important role of PGC-1alpha in bile acid homeostasis and suggest that pharmacological targeting of farnesoid X receptor in vivo can be used to reverse the increase in CYP7A1 associated with adverse metabolic conditions.

  6. Structure-function analysis of heterodimer formation, oligomerization, and receptor binding of the Staphylococcus aureus bi-component toxin LukGH. (United States)

    Badarau, Adriana; Rouha, Harald; Malafa, Stefan; Logan, Derek T; Håkansson, Maria; Stulik, Lukas; Dolezilkova, Ivana; Teubenbacher, Astrid; Gross, Karin; Maierhofer, Barbara; Weber, Susanne; Jägerhofer, Michaela; Hoffman, David; Nagy, Eszter


    The bi-component leukocidins of Staphylococcus aureus are important virulence factors that lyse human phagocytic cells and contribute to immune evasion. The γ-hemolysins (HlgAB and HlgCB) and Panton-Valentine leukocidin (PVL or LukSF) were shown to assemble from soluble subunits into membrane-bound oligomers on the surface of target cells, creating barrel-like pore structures that lead to cell lysis. LukGH is the most distantly related member of this toxin family, sharing only 30-40% amino acid sequence identity with the others. We observed that, unlike other leukocidin subunits, recombinant LukH and LukG had low solubility and were unable to bind to target cells, unless both components were present. Using biolayer interferometry and intrinsic tryptophan fluorescence we detected binding of LukH to LukG in solution with an affinity in the low nanomolar range and dynamic light scattering measurements confirmed formation of a heterodimer. We elucidated the structure of LukGH by x-ray crystallography at 2.8-Å resolution. This revealed an octameric structure that strongly resembles that reported for HlgAB, but with important structural differences. Structure guided mutagenesis studies demonstrated that three salt bridges, not found in other bi-component leukocidins, are essential for dimer formation in solution and receptor binding. We detected weak binding of LukH, but not LukG, to the cellular receptor CD11b by biolayer interferometry, suggesting that in common with other members of this toxin family, the S-component has the primary contact role with the receptor. These new insights provide the basis for novel strategies to counteract this powerful toxin and Staphylococcus aureus pathogenesis.

  7. The complete chloroplast DNA sequence of the green alga Oltmannsiellopsis viridis reveals a distinctive quadripartite architecture in the chloroplast genome of early diverging ulvophytes

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    Lemieux Claude


    Full Text Available Abstract Background The phylum Chlorophyta contains the majority of the green algae and is divided into four classes. The basal position of the Prasinophyceae has been well documented, but the divergence order of the Ulvophyceae, Trebouxiophyceae and Chlorophyceae is currently debated. The four complete chloroplast DNA (cpDNA sequences presently available for representatives of these classes have revealed extensive variability in overall structure, gene content, intron composition and gene order. The chloroplast genome of Pseudendoclonium (Ulvophyceae, in particular, is characterized by an atypical quadripartite architecture that deviates from the ancestral type by a large inverted repeat (IR featuring an inverted rRNA operon and a small single-copy (SSC region containing 14 genes normally found in the large single-copy (LSC region. To gain insights into the nature of the events that led to the reorganization of the chloroplast genome in the Ulvophyceae, we have determined the complete cpDNA sequence of Oltmannsiellopsis viridis, a representative of a distinct, early diverging lineage. Results The 151,933 bp IR-containing genome of Oltmannsiellopsis differs considerably from Pseudendoclonium and other chlorophyte cpDNAs in intron content and gene order, but shares close similarities with its ulvophyte homologue at the levels of quadripartite architecture, gene content and gene density. Oltmannsiellopsis cpDNA encodes 105 genes, contains five group I introns, and features many short dispersed repeats. As in Pseudendoclonium cpDNA, the rRNA genes in the IR are transcribed toward the single copy region featuring the genes typically found in the ancestral LSC region, and the opposite single copy region harbours genes characteristic of both the ancestral SSC and LSC regions. The 52 genes that were transferred from the ancestral LSC to SSC region include 12 of those observed in Pseudendoclonium cpDNA. Surprisingly, the overall gene organization of

  8. Diferenças morfológicas entre Amaranthus cruentus, cv. BRS Alegria, e as plantas daninhas A. hybridus, A. retroflexus, A. viridis e A. spinosus Morphological differences between Amaranthus cruentus, cv. BRS Alegria, and the weed species A. hybridus, A. retroflexus, A. viridis and A. spinosus

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    C.R. Spehar


    Full Text Available O pseudocereal amaranto, com as espécies Amaranthus caudatus, A. cruentus e A. hypochondriacus, domesticado pelas populações indígenas antes que a América fosse descoberta, tem se adaptado aos sistemas produtivos dos cerrados. A planta apresenta panículas apicais, divididas em pequenos ramos com frutos do tipo pixídio, com uma semente cada. Estas germinam rapidamente em presença de umidade, após atingirem a maturação fisiológica. No início da fase vegetativa, o amaranto cultivado pode confundir-se com espécies de plantas daninhas do mesmo gênero (A. hybridus, A. retroflexus, A. viridis e A. spinosus, as quais estão associadas à expansão agrícola. As diferenças morfológicas tornam-se mais visíveis após o florescimento: ramificações com flores axilares e terminais, em contraste com o amaranto, no qual a inflorescência (panícula é apical; as sementes claras das espécies cultivadas contrastam com as das invasoras, que são escuras. BRS Alegria (A. cruentus, cultivar pioneiro no Brasil, apresenta plantas com 180 cm, das quais a panícula ocupa 48 cm; maturação fisiológica aos 90 dias; resistência ao acamamento; e 0,68 g por 1.000 sementes, com produção de 2,3 t ha¹ (sementes e 5,6 t ha-1 (biomassa total. As sementes nas plantas daninhas são menores, germinam gradativamente e podem permanecer no solo por muitos anos, infestando as áreas. As diferenças morfológicas detectadas na experimentação demonstram que as espécies são distinguíveis; elas contribuem para orientar a produção de sementes e o cultivo comercial de amaranto, enfatizando as características de adaptação, em contraste com as das invasoras do mesmo gênero botânico.The pseudocereal grain amaranth, with the species Amaranthus caudatus, A. ruentus e A. hypochondriacus, domesticated by indigenous populations before America was discovered, has shown adaptability to production systems in the Brazilian savannah. The plants present apical

  9. Estabilidad temporal de las infracomunidades de parásitos en la borrachilla Scartichthys viridis (Valenciennes, 1836 (Pisces : Blenniidae en la costa central de Chile Temporal stability in parasite infracommunities of the blenny Scartichthys viridis(Valenciennes, 1836 (Pisces: Blenniidae on the central coast of Chile

    Directory of Open Access Journals (Sweden)



    Full Text Available Se comparan las infracomunidades de parásitos de la borrachilla Scartichthys viridis (Pisces: Blenniidae de tres muestras tomadas en un lapso de 17 meses, entre 1999 y 2001, desde pozas intermareales vecinas a Las Cruces (33°27' S, 71°37' O, Chile central. El objetivo es averiguar si la riqueza, diversidad, abundancia y composición de las infracomunidades de parásitos son persistentes o no en el tiempo ontogenético y cronológico. Se recolectaron 10 taxa parasitarios en cerca del 89 % de los 63 huéspedes examinados, de los cuales ocho eran metazoarios. La búsqueda de protozoos se realizó sólo en los últimos 2 años. El 75 % de los ocho taxa de metazoos ocurrieron en los tres años, uno no estuvo presente en un año, y otro fue encontrado solamente en un año. La mayoría de los huéspedes examinados albergaba protozoos parásitos. La prevalencia de los protozoos Cryptobia sp. fue alta para ambos años, y menor en Trichodina sp. La longitud total de los huéspedes era un predictor relevante de las variaciones en la riqueza, abundancia, diversidad y composición infracomunitaria en el conjunto de los tres años. En cambio, el año de muestreo no lo fue, en particular al comparar entre huéspedes de similar longitud total. Estos resultados son similares a los encontrados en infracomunidades de parásitos de otras especies de peces en Chile, en que hay baja variabilidad en las propiedades agregadas de las infracomunidades en el tiempo cronológico. Se discute acerca de la extensión relativa del tiempo ontogenético en contraste al tiempo cronológico al ser probablemente ambos de importancia en las características de las infracomunidades, y se propone que se explore la medida en la cual estos resultados constituyen un patrón.Parasite infracommunities of the blenny Scartichthys viridis (Pisces: Blenniidae are compared among three samples taken within a 17-month period during three consecutive years (1999-2001, from intertidal pools at

  10. The inhibition of the human cholesterol 7α-hydroxylase gene (CYP7A1) promoter by fibrates in cultured cells is mediated via the liver x receptor α and peroxisome proliferator-activated receptor α heterodimer


    Gbaguidi, G. Franck; Agellon, Luis B.


    In previous work, we showed that the binding of the liver x receptor α:peroxisome proliferator-activated receptor α (LXRα:PPARα) heterodimer to the murine Cyp7a1 gene promoter antagonizes the stimulatory effect of their respective ligands. In this study, we determined if LXRα:PPARα can also regulate human CYP7A1 gene promoter activity. Co-expression of LXRα and PPARα in McArdle RH7777 hepatoma cells decreased the activity of the human CYP7A1 gene promoter in response to fibrates and 25-hydrox...

  11. Radiation Dose and Risk Assessments from Polonium-210 in Green Mussels (Perna viridis) and Seafood Consumers Living nearby the Industrial Area in Chonburi Province, Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Tumnoi, Y.; Phaopeng, N. [Office of Atoms for Peace - OAP (Thailand)


    Marine environmental samples including seawater (filtered and unfiltered), suspended particles, and green mussels (Perna viridis) were collected from Sriracha and Angsira areas located in Chonburi province in order to determine Po-210 radioactivity. The former was chosen because it is generally believed that this area has been contaminated by one of the largest industrial estates in Thailand and others human-activities (non-nuclear activities) nearby such as oil refineries and Coal Power Plants. Discharges, ashes, and wastes released from these activities may result in an increase of Po-210 concentration in marine environment when compared to other areas. The later was designated to serve as a control site in this study since this area is unlikely to be impacted by industrial activities. Our results revealed that, in the filtered seawater, averaged values of Po-210 level were 0.26 + 0.14 mBq/L (Sriracha) and 0.56 + 0.42 mBq/L (Angsira) and, in the unfiltered seawater, means of Po-210 radioactivity were 2.37 + 0.32 mBq/L (Sriracha) and 4.20 + 2.78 mBq/L (Angsira). Furthermore, the suspended particles contained Po-210 concentrations with averaged values of 14.11 + 8.87 Bq/kg dw (Sriracha) and 102.21 + 51.49 Bq/kg dw (Angsira) while averaged Po-210 levels of 35.74 + 17.53 Bq/kg dw (Sriracha) and 71.12 + 62.88 Bq/kg dw (Angsira) were found in the green mussels examined. The present finding indicates that there is no radiological impact caused by those human activities to the marine environment at Sriracha. Radiation dose assessment was also performed in both the green mussels and human who consume green mussels. The results show that the green mussels farmed at Sriracha and Angsira received averaged radiation dose rates from Po-210 at 0.0007 and 0.0015 mGy/d, respectively. In addition, our results reveal that populations living in Chonburi province and ingesting the green mussels from these 2 locations received radiation dose rates from Po-210 at the means of 44.25 and

  12. Visualizing a protein quake with time-resolved X-ray scattering at a free-electron laser

    DEFF Research Database (Denmark)

    Arnlund, David; Johansson, Linda C.; Wickstrand, Cecilia;


    We describe a method to measure ultrafast protein structural changes using time-resolved wide-angle X-ray scattering at an X-ray free-electron laser. We demonstrated this approach using multiphoton excitation of the Blastochloris viridis photosynthetic reaction center, observing an ultrafast global...... conformational change that arises within picoseconds and precedes the propagation of heat through the protein. This provides direct structural evidence for a 'protein quake': the hypothesis that proteins rapidly dissipate energy through quake-like structural motions....

  13. Anti-Fatigue Effect Derived from Compound Enzyme Hydrolysates of Perna Viridis Meat%翡翠贻贝肉复合酶解物的抗疲劳作用

    Institute of Scientific and Technical Information of China (English)

    方富永; 苗艳丽; 程诚; 马孝甜; 陈木连; 宋文东


    Objective:To study the anti-fatigue function from compound enzyme hydrolysates of Perna Viridis meat by mice experiments. Method: Five groups of mice were divided into low-dose group, medium-dose group, high-dose group, original meat group and control group. Low, medium and high dose group were given hydrolysates, which were prepared with papain, neutral protease and pineapple proteinase in turn. Original meat group and control were respectively given Perna Viridis meat powder and saline similarly for 30 days. Blood lactic acid, blood urea nitrogen, liver glyco-gen,and the time of loaded swimming were measured to study anti-fatigue function. Results:Compared with the control, High-dose group could significantly decreased the blood lactic acid and blood urea nitrogen (P0.05). Conclusion:Compound enzyme Hydrolysates of Perna Viridis meat has anti-fatigue effects by mice experiments.%目的:通过动物实验研究翡翠贻贝肉复合酶解物的抗疲劳效果.方法:将昆明种小鼠分成5组,设低、中、高剂量组、原肉组和对照组.翡翠贻贝肉浆依次以木瓜蛋白酶、中性蛋白酶、菠萝蛋白酶水解制备酶解物,用于3个剂量组的小鼠灌胃.原肉组和对照组分别以翡翠贻贝肉原肉粉及生理盐水灌胃.连续灌胃30 d后,测定各组小鼠运动后血乳酸、血清尿素氮浓度及肝糖原含量,观察负重游泳时间,根据试验结果判断抗疲劳效果.结果:与对照组比较,翡翠贻贝肉复合酶解物高剂量组小鼠运动后血乳酸及血清尿素氮浓度降低极显著(P<0.01),肝糖原含量显著升高(P<0.05),负重游泳时间显著延长(P<0.05);中、低剂量组、原肉组与对照组相比,上述各项试验指标均无显著性影响(P>0.05).结论:动物实验证明翡翠贻贝肉复合酶解物具有抗疲劳作用.

  14. The inhibition of the human cholesterol 7alpha-hydroxylase gene (CYP7A1) promoter by fibrates in cultured cells is mediated via the liver x receptor alpha and peroxisome proliferator-activated receptor alpha heterodimer. (United States)

    Gbaguidi, G Franck; Agellon, Luis B


    In previous work, we showed that the binding of the liver x receptor alpha:peroxisome proliferator-activated receptor alpha (LXRalpha:PPARalpha) heterodimer to the murine Cyp7a1 gene promoter antagonizes the stimulatory effect of their respective ligands. In this study, we determined if LXRalpha:PPARalpha can also regulate human CYP7A1 gene promoter activity. Co-expression of LXRalpha and PPARalpha in McArdle RH7777 hepatoma cells decreased the activity of the human CYP7A1 gene promoter in response to fibrates and 25-hydroxycholesterol. In vitro, the human CYP7A1 Site I bound LXRalpha:PPARalpha, although with substantially less affinity compared with the murine Cyp7a1 Site I. The binding of LXRalpha:PPARalpha to human CYP7A1 Site I was increased in the presence of either LXRalpha or PPARalpha ligands. In HepG2 hepatoblastoma cells, fibrates and 25-hydroxycholesterol inhibited the expression of the endogenous CYP7A1 gene as well as the human CYP7A1 gene promoter when co-transfected with plasmids encoding LXRalpha and PPARalpha. However, a derivative of the human CYP7A1 gene promoter that contains a mutant form of Site I that does not bind LXRalpha:PPARalpha was not inhibited by WY 14,643 or 25-hydroxycholesterol in both McArdle RH7777 and HepG2 cells. The ligand-dependent recruitment of LXRalpha:PPARalpha heterodimer onto the human CYP7A1 Site I can explain the inhibition of the human CYP7A1 gene promoter in response to fibrates and 25-hydroxycholesterol.

  15. Sociālās kritikas elementi Luisa Bunjuela daiļradē: filmas Viridiāna, Iznīcības eņģelis un Dienas skaistule


    Usāne, Sintija


    Bakalura darbs „Sociālās kritikas elementi Luisa Bunjuela daiļradē: filmas Viridiāna, Iznīcības eņģelis un Dienas skaistule” ir pētījums, kā vēsturisko un politisko notikumu attīstības gaita ietekmēja Luisa Bunjuela daiļradi. Bakalaura darba galvenais mērķis bija analizēt filmā iekļautos sabiedrības un reliģiskās kritikas elementus. Pētījuma teorētiskā daļa sastāv no 3 apakšnodaļām. Katrā apakšnodaļā tiek apskatīti vēsturiskie un politiskie notikumi Spānijā, Meksikā un Francijā. Tāpa...

  16. MAR序列介导野苋菜凝集素基因在白菜中的表达%Expression of Amaranthus viridis L. Agglutinin Mediated by Matrix Attachment Region (MAR) Sequence in Transgenic Chinese Cabbage

    Institute of Scientific and Technical Information of China (English)

    邓智年; 魏源文; 吕维莉; 李杨瑞


    以'丰顺'白菜带柄子叶为转化受体,用带有MAR(Matrix Attachment Region)和不带MAR的两种植物表达载体进行农杆菌介导转化野苋菜凝集素基因(Amaranthus viridis L. agglutinin,AVA)获得转基因的抗蚜小白菜.分析MAR序列介导对转基因表达的影响.表明利用MAR序列介导AVA基因表达,获得转基因植株的数量比对照提高29.63%;转AVA基因白菜对桃蚜(Myzus persicae)的群体发展有一定的抑制作用,平均抑制率为55.8%;MAR序列介导AVA基因表达的转基因植株中,该基因的表达水平比对照高,并且不同转基因单株间AVA基因表达差异比对照小.

  17. 普洱市小粒咖啡绿蚧田间药效试验研究%The Field Efficacy Trials on Coccus viridis(Green) of Arabica Coffee in Pu′er City

    Institute of Scientific and Technical Information of China (English)

    丁丽芬; 马巾媛; 宋国敏; 何素明; 何丽


    进行小粒咖啡绿蚧的田间药效试验,结果表明:5%吡虫啉乳油、25%噻虫嗪可湿性粉剂、5%啶虫脒乳油、40%杀扑磷乳油平均防效均在91%以上,说明它们具有很好的速效性和持效性。在7中药剂中药效最好的是5%啶虫脒乳油,平均防效为94.10%,其次是40%杀扑磷乳油,平均防效为92.95%,药效最差的是2%阿维菌素乳油,平均防效仅为54.23%。%The field efficacy trial on Coccus viridis(Green) of arabica coffee was conducted,the results showed that among 7 agents,average control efficiencies of 5%imidacloprid EC ,25%thiamethoxam WG ,5%acetamiprid EC and 40%methidathion EC were all above 91%,which meant that they all had quick result and bolding effect. 5% acetamiprid EC had the best control efficiency which was 94.10% ,the following was 40%methidathion EC,whose average control efficiency was 92.95%,2%avermectin EC had the worst average control efficiency which was 54.23%.

  18. 野苋菜凝集素基因的克隆及抗蚜性%Cloning of AVA Gene from Amaranthus viridis and Effect of Aphid Resistance on Transgenic Tobacco Plants

    Institute of Scientific and Technical Information of China (English)

    邓智年; 李楠; 魏源文; 吕维莉; 李杨瑞


    通过PCR从苋科植物野苋菜Amaranthus viridis L.基因组DNA中扩增出野苋菜凝集素的核基因片段AVA.序列分析结果表明该基因为1 831 bp,含有一个922 bp的内含子和两个分别为212 bp和697 bp的外显子.采用反向PCR技术获得了该基因的编码区克隆.分别构建含有内含子和不含内含子的AVA基因植物表达载体pBI121AVA-GUS和pBI121AVAc-GUS,通过根癌农杆菌介导法转化烟草.PCR、GUS检测结果均表明AVA基因不仅已整合到烟草基因组DNA中,而且初步表明转基因烟草有AVA蛋白表达.抗蚜实验表明含内含子和无内含子的AVA基因在转基因烟草中的抗蚜能力不同,转AVA和AVAc烟草对蚜虫的抑制率分别为60.81%和50.63%,有的植株高达97%.实验结果表明所克隆的AVA基因是具有抗蚜能力的苋菜凝集素基因家族中的新成员.

  19. Ligand-dependent regulation of the activity of the orphan nuclear receptor, small heterodimer partner (SHP), in the repression of bile acid biosynthetic CYP7A1 and CYP8B1 genes. (United States)

    Miao, Ji; Choi, Sung-E; Seok, Sun Mi; Yang, Linda; Zuercher, William J; Xu, Yong; Willson, Timothy M; Xu, H Eric; Kemper, Jongsook Kim


    Small heterodimer partner (SHP) plays important roles in diverse biological processes by directly interacting with transcription factors and inhibiting their activities. SHP has been designated an orphan nuclear receptor, but whether its activity can be modulated by ligands has been a long-standing question. Recently, retinoid-related molecules, including 4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3Cl-AHPC), were shown to bind to SHP and enhance apoptosis. We have examined whether 3Cl-AHPC acts as an agonist and increases SHP activity in the repression of bile acid biosynthetic CYP7A1 and CYP8B1 genes and delineated the underlying mechanisms. Contrary to this expectation, micromolar concentrations of 3Cl-AHPC increased CYP7A1 expression but indirectly via p38 kinase signaling. Nanomolar concentrations, however, repressed CYP7A1 expression and decreased bile acid levels in HepG2 cells, and little repression was observed when SHP was down-regulated by small hairpin RNA. Mechanistic studies revealed that 3Cl-AHPC bound to SHP, increased the interaction of SHP with liver receptor homologue (LRH)-1, a hepatic activator for CYP7A1 and CYP8B1 genes, and with repressive cofactors, Brahma, mammalian Sin3a, and histone deacetylase-1, and, subsequently, increased the occupancy of SHP and these cofactors at the promoters. Mutation of Leu-100, predicted to contact 3Cl-AHPC within the SHP ligand binding pocket by molecular modeling, severely impaired the increased interaction with LRH-1, and repression of LRH-1 activity mediated by 3Cl-AHPC. 3Cl-AHPC repressed SHP metabolic target genes in a gene-specific manner in human primary hepatocytes and HepG2 cells. These data suggest that SHP may act as a ligand-regulated receptor in metabolic pathways. Modulation of SHP activity by synthetic ligands may be a useful therapeutic strategy.

  20. Solution structure of human P1•P2 heterodimer provides insights into the role of eukaryotic stalk in recruiting the ribosome-inactivating protein trichosanthin to the ribosome. (United States)

    Lee, Ka-Ming; Yusa, Kazuyuki; Chu, Lai-On; Yu, Conny Wing-Heng; Oono, Moe; Miyoshi, Tomohiro; Ito, Kosuke; Shaw, Pang-Chui; Wong, Kam-Bo; Uchiumi, Toshio


    Lateral ribosomal stalk is responsible for binding and recruiting translation factors during protein synthesis. The eukaryotic stalk consists of one P0 protein with two copies of P1•P2 heterodimers to form a P0(P1•P2)₂ pentameric P-complex. Here, we have solved the structure of full-length P1•P2 by nuclear magnetic resonance spectroscopy. P1 and P2 dimerize via their helical N-terminal domains, whereas the C-terminal tails of P1•P2 are unstructured and can extend up to ∼125 Å away from the dimerization domains. (15)N relaxation study reveals that the C-terminal tails are flexible, having a much faster internal mobility than the N-terminal domains. Replacement of prokaryotic L10(L7/L12)₄/L11 by eukaryotic P0(P1•P2)₂/eL12 rendered Escherichia coli ribosome, which is insensitive to trichosanthin (TCS), susceptible to depurination by TCS and the C-terminal tail was found to be responsible for this depurination. Truncation and insertion studies showed that depurination of hybrid ribosome is dependent on the length of the proline-alanine rich hinge region within the C-terminal tail. All together, we propose a model that recruitment of TCS to the sarcin-ricin loop required the flexible C-terminal tail, and the proline-alanine rich hinge region lengthens this C-terminal tail, allowing the tail to sweep around the ribosome to recruit TCS.

  1. Degradation of phycobilisomes in Synechocystis sp. PCC6803: evidence for essential formation of an NblA1/NblA2 heterodimer and its codegradation by A Clp protease complex. (United States)

    Baier, Antje; Winkler, Wiebke; Korte, Thomas; Lockau, Wolfgang; Karradt, Anne


    When cyanobacteria acclimate to nitrogen deficiency, they degrade their large (3-5-MDa), light-harvesting complexes, the phycobilisomes. This massive, yet specific, intracellular degradation of the pigmented phycobiliproteins causes a color change of cyanobacterial cultures from blue-green to yellow-green, a process referred to as chlorosis or bleaching. Phycobilisome degradation is induced by expression of the nblA gene, which encodes a protein of ~7 kDa. NblA most likely acts as an adaptor protein that guides a Clp protease to the phycobiliproteins, thereby initiating the degradation process. Most cyanobacteria and red algae possess just one nblA-homologous gene. As an exception, the widely used "model organism" Synechocystis sp. PCC6803 expresses two such genes, nblA16803 and nblA26803, both of whose products are required for phycobilisome degradation. Here, we demonstrate that the two NblA proteins heterodimerize in vitro and in vivo using pull-down assays and a Förster energy-transfer approach, respectively. We further show that the NblA proteins form a ternary complex with ClpC (the HSP100 chaperone partner of Clp proteases) and phycobiliproteins in vitro. This complex is susceptible to ATP-dependent degradation by a Clp protease, a finding that supports a proposed mechanism of the degradation process. Expression of the single nblA gene encoded by the genome of the N2-fixing, filamentous cyanobacterium Nostoc sp. PCC7120 in the nblA1/nblA2 mutant of Synechocystis sp. PCC6803 induced phycobilisome degradation, suggesting that the function of the NblA heterodimer of Synechocystis sp. PCC6803 is combined in the homodimeric protein of Nostoc sp. PCC7120.

  2. On Moniligaster coeruleus Horst (Moniligaster viridis Beddard)

    NARCIS (Netherlands)

    Horst, R.


    In my description of this large earthworm from Borneo ¹) I made already the suggestion, that the species probably did not belong to the genus Moniligaster, but I preferred to range it provisionally in this genus till we were better informed about the characters of several Moniligaster- species, only

  3. Suppression of population transport and control of exciton distributions by entangled photons. (United States)

    Schlawin, Frank; Dorfman, Konstantin E; Fingerhut, Benjamin P; Mukamel, Shaul


    Entangled photons provide an important tool for secure quantum communication, computing and lithography. Low intensity requirements for multi-photon processes make them idealy suited for minimizing damage in imaging applications. Here we show how their unique temporal and spectral features may be used in nonlinear spectroscopy to reveal properties of multiexcitons in chromophore aggregates. Simulations demostrate that they provide unique control tools for two-exciton states in the bacterial reaction centre of Blastochloris viridis. Population transport in the intermediate single-exciton manifold may be suppressed by the absorption of photon pairs with short entanglement time, thus allowing the manipulation of the distribution of two-exciton states. The quantum nature of the light is essential for achieving this degree of control, which cannot be reproduced by stochastic or chirped light. Classical light is fundamentally limited by the frequency-time uncertainty, whereas entangled photons have independent temporal and spectral characteristics not subjected to this uncertainty.

  4. NaHCO3浓度对等鞭藻3011、等鞭藻塔溪堤品系和绿色巴夫藻生长的影响%Effect of NaHCO3 concentration on growth of Isochrysis galbana 3011 strain, Tahitian I.galbana strain and Pavlova viridis

    Institute of Scientific and Technical Information of China (English)

    梁英; 麦康森; 孙世春; 梁广尧


    对等鞭藻3011(Isochrysis galbana3011)、等鞭藻塔溪堤品系(Tahitian Isochrysisgalbana)和绿色巴夫藻(Pavlova viridisai)3株微藻种进行培养。NaHCO3的质量浓度分别为0,200,400,800,1200和1600mg/L,培养温度(22±1)℃,盐度28,光照强度5000lx。结果表明,NaHCO3的浓度对3株微藻生长的影响差异显著,经过6d的培养,培养液中不加NaHCO3、但连续充气组中3株微藻的细胞浓度都达到最大值;除充气不加NaHCO3组外,3株微藻的细胞浓度都在NaHCO3 1600mg/L组中达到最大值。%NaHCO3 concentrations were designed at 100,200, 400, 800, 1 200and 1 600 mg/L. Three marine microalgal strains (Isochrysis galbana 3011, Tahitian Isochrysis galbana and Pavlova viridis)were cultured at water temperature (22±1)℃; the salinity was adjusted to 28 by using distilled water,and the light intensity was 5 000 lx. The results showed that NaHCO3 had significant influence on the growth of the 3 marine microalgal strains. After 6 days culture, the 3 marine microalgal strains all grew the best when NaHCO3 concentration was 0 mg/L with continuously air-bubbling (aerating groups). Except that, the optimum NaHCO3 concentration for the highest cell density of I.galbana 3011, Tahitian I.galbana and P.viridis were all at 1 600 mg/L.

  5. Tertiary Structural studies of Myotoxin a from Crotalus viridis viridis Venom by Nuclear Magnetic Resonance (United States)


    electrophorus electri... 47 47 47 Sw:Ibb2SWheat P09864 wheat (triticum aestivum). proteina ... 46 46 51 Sw:Pa29$Pseau P20253 mulga snake (pseudechis...Sw:Pa2bSPsepo P20259 red-bellied black snake (pseudechis... 34 46 37 Sw:IbblSWheat P09863 wheat (triticum aestivum). proteina ... 46 46 52 Sw:Pa2a$Psepo P20258 red

  6. 骨钙素在BMP2/7异源二聚体诱导种植体周围骨缺损再生中的表达%Expression of osteocalcin using rhBMP2/7 heterodimer in peri-implant bone defects compared to BMP2 homodimer and BMP7 homodimer

    Institute of Scientific and Technical Information of China (English)

    孙平; 王利民; 冯剑颖


    目的:研究骨钙素在使用BMP2/7异源二聚体促进种植体周骨缺损再生中的表达.方法:建立小型猪种植体周骨缺损模型,并使用BMP2/7异源二聚体及BMP2、BMP7同源二聚体促进骨再生,采用免疫组化方法分别在2、3、6周时检测新骨中骨钙素表达.结果:在各实验组中,骨钙素3周时表达达到最高值.在2、3、6周,BMP2/7组骨钙素表达均强于BMP2、BMP7同源二聚体组及对照组.结论:在以同样较低浓度(30ng/ml)作用于小型猪种植体周骨缺损诱导新骨形成过程中,BMP2/7异源二聚体较BMP、BMP7同源二聚体有效促进骨钙素的表达.%To delineate expression of osteocalcin induced by recombinant human bone morphogenetic protein (BMP)2/7 heterodimer in peri-implant bone defects in comparison to BMP2 and BMP7 homodimer.Methods: Identical peri-implant bone defects were created on the frontal skull of minipig. Collagen sponges with the same dose BMP2/7 heterodimer、 BMP2 homodimer 、 BMP7 homodimer 、 or BMPs were adopted to treat the freshly created implant bed. Titanium implants were centrally implanted with 4mm-flxture within bone defects. Immunohistochemical method was applied to evaluate the expression of osteocalcin (OCN) after 2, 3, and 6 weeks of implantation. Results: The OCN proteins displayed intensity peaks at 3 weeks (P<0.05) in all the groups. Immunoreactive expression of OCN of BMP2/7 group was more intensity than BMP2、 BMP7 and control group at 2, 3, and 6 weeks post-operation (P<0.05). Conclusions: Purified recombinant human BMP2/7 heterodimer can enhance the expression of OCN with significant differences over BMP2 homodimers or BMP7 homodimers with the same low-dose (30ng/ml).

  7. Changes of cholesterol 7alpha-hydroxylase,farnesoid X receptor,and small heterodimer partner expression in liver tissues of rats with obstructive cholestasis%阻塞性胆汁淤积大鼠肝脏胆固醇7α-羟化酶和核受体FXR、SHP表达变化

    Institute of Scientific and Technical Information of China (English)

    吴晓平; 柴进; 陈文生


    目的:通过建立梗阻性黄疸动物模型,观察胆固醇7α-羟化酶(cholesterol 7alpha-hydroxylase,CYP7A1)、类法尼醇X受体(farnesoid X receptor,FXR)及小异源二聚体伴侣受体(small heterodimer partner,SHP)的表达变化,并分析CYP7A1和FXR、SHP之问的关系.方法:采用胆总管结扎术制备大鼠梗阻性黄疸模型,分别于术后1、3、14 d麻醉后放血处死.取大鼠肝脏,抽提总RNA,采用实时定量RT-PCR检测CYP7A1 mRNA表达;提取肝细胞核蛋白,采用蛋白质印迹技术检测FXR和SHP蛋白表达.结果:与假手术对照组相比,梗阻性黄疸组大鼠肝细胞CYP7A1 mRNA表达明显增强,FXR和SHP蛋白表达同步降低,差异均有统计学意义(P<0.001,P<0.05).结论:CYP7A1表达增强可能与FXR、SHP表达减弱有关.




    Изучена зависимость содержания витаминов от экологических условий в растении Fragaria viridis Duch. (Weston) землянике зелёной, или клубнике. Результаты исследований показывают, что содержание антиоксидантов аскробиновой кислоты, токоферола и каротина в листьях Fragaria viridis обусловлено фазой развития растений и их местообитанием. Показано повышенное содержание токоферола в листьях растения, произрастающего в зоне влияния промышленных поллютантов, что, возможно, является одним из механизмо...

  9. Efeito de cascas de café e de arroz dispostas nas camadas do solo sobre a germinação e o crescimento inicial do caruru-de-mancha Allelopathic effect of coffee and rice husks arranged in soil layers on the germination and initial growth of Amaranthus viridis

    Directory of Open Access Journals (Sweden)

    J.C.F. Santos


    Full Text Available Estudos dos efeitos dos resíduos de plantas pela utilização de coberturas mortas no controle das plantas daninhas têm apresentado dificuldade de determinar a diferenciação entre alelopatia e competição. Atualmente, muitas pesquisas têm se referido a critérios que propõem evidência à alelopatia. Este trabalho em casa de vegetação visou determinar os efeitos alelopáticos proporcionados pelas cascas de café e de arroz sobre o caruru-de-mancha, por meio das disposições desses resíduos nas camadas do solo. O delineamento experimental foi o de blocos casualizados, com os tratamentos em quatro repetições e organizados num esquema fatorial (3x3, sendo cascas de café e de arroz e vermiculita expandida como um fator e suas disposições, com resíduos depositados no topo, incorporados na superfície e incorporados no fundo, como segundo fator. Como testemunha foi usado um tratamento adicional sem cobertura. De modo geral, resíduos de cascas proporcionaram inibição da germinação e estímulo ao crescimento do caruru-de-mancha. A casca de arroz proporcionou menor índice de velocidade de emergência e germinação de sementes do que a casca de café. A casca de café depositada no topo proporcionou maior crescimento e maior peso da matéria seca do caruru-de-mancha, seguido pela mesma casca incorporada na superfície do solo.Studies of plant residue effects involving mulches to control weeds in perennial crops are difficult to carry out due to the need to differentiate between allelopathy and competition. Many researches, nowadays, refer to criteria proving allelopathy. This work was established under greenhouse conditions to determine the allelopathic effects of coffee and rice husks on Amaranthus viridis through their arrangements in soil layers. The experimental design was a randomized block with four replications, arranged in a 3 x 3 factorial scheme, with coffee and rice husks and expanded vermiculite being one factor and

  10. 腺病毒介导BMP2和BMP7基因共转染骨髓间充质干细胞表达人BMP2/7异源二聚体%The feasibility of adenoviral co-transduction of BMP2 and BMP7 for the expression of recombinant human BMP2/7 heterodimer in rat bone marrow mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    高涛; 唐胜建; 牛常英; 苗春雷; 张伟; 周陆陆; 吴彩风; 刘方军


    Objective To investigate the feasibility of rat bone marrow mesenchymal stem cells (BMSCs) as the target cell of adenovirus-mediated co-transduction of BMP2 and BMP7 genes and then facilitate the expression of recombinant BMP2/7 heterodimer protein.Methods 3 adult male Fischer 344 rats of about 10 weeks of age were used for harvest and in vitro culture of rat BMSCs.Recombinant adenovirus vector carrying BMP2 or BMP7 target genes were constructed with AdMax vector system,and production of high-titer adenoviruses were packaged with HEK293T cells and then concentrated with CSCl2 density-gradient ultra-centrifugation.Rat BMSCs from passage 3 were seeded in 6-well plates at the concentration of 10 000 cells/cm2.After overnight pre-culture,BMSCs were allowed to culture in 200 μl serum-free alpha MEM containing both Ad-BMP2 and Ad-BMP7 adenovirus (100 MOI of each virus).After 7 days in vitro culture,conditioned cell culture supernatants were collected and followed by immunoprecipitation through immune protein G columns pre-loaded with mouse anti-human BMP7 antibody.The resulted protein immune-precipitates were used to assay the expression of BMP2/7 heterodimers via Western Blot and ELISA assay.As a negative control,Rat BMSCs were also genetically transduced with Ad-GFP virus at a concentration of 200 MOI.Results Our data demonstrated that recombinant adenoviruses carrying BMP2 or BMP7 target gene was successfully reconstructed,packaged,and confirmed via Western Blot assay,which as respected,presented as an unique band at 55 000 size for BMP2 or 49 000 size for BMP7.Adenovirus Ad-GFP was used to verify the integrity of recombinant virus and its transfection efficiency in rat BMSCs,which showed well cell attachment to culture plate and had no cytotoxicity.Green fluorescent protein in BMSCs was also noted eminently under fluorescent microscope.Combined transduction with AdBMP2 plus Ad-BMP7 resulted in the formation of BMP2/7 heterodimers from rat BMSCs.Analysis of

  11. 骨形态发生蛋白2/7异二聚体对人脂肪间充质干细胞成骨分化的促进作用%Promoted role of bone morphogenetic protein 2/7 heterodimer in the osteogenic differentiation of human adipose-derived stem cells

    Institute of Scientific and Technical Information of China (English)

    张晓; 刘云松; 吕珑薇; 陈彤; 吴刚; 周永胜


    Objective:To investigate the role of bone morphogenetic protein 2/7 heterodimer (BMP-2/7)in the osteogenesis of human adipose-derived stem cells (hASCs).Methods:hASCs were exposed to three different treatments in vitro:osteogenic medium with 1 50 μg/L BMP-2/7 (experimental group), osteogenic medium alone (OM group)and proliferation medium (PM group).After 1 ,4 and 7 days of osteogenic induction,the amount of cellular DNA was measured to investigate the cytotoxicity.After 7 and 1 4 days,alkaline phosphatase (ALP)staining and quantification were performed to test the activity of ALP.After 21 and 28 days,the calcification deposition was determined by Alizarin Red S (ARS)stai-ning and quantification.The expressions of the osteoblast-related genes were tested on days 1 ,4,7 and 1 4.In the in vivo study,6 nude mice were used and 4 groups were set and implanted subcutaneously into the back of nude mice:(1 )β-TCP scaffold only (scaffold control group );(2 )β-TCP scaffold with hASCs cultured by PMin vitro for 1 week (PMcontrol group);(3)β-TCP scaffold with hASCs cultured by OM in vitro for 1 week (OM control group);(4)β-TCP scaffold with hASCs cultured by OM with 1 50 μg/L BMP-2/7 in vitro for 1 week (test group).After 4 weeks of implantation,histological staining was performed to evaluate the in vivo osteogenesis of hASCs.Results:After induction for 1 day,there was no significant difference between the experimental group and the PM group on the cellular DNA con-tent (P>0.05 ).After 4 days,the cellular DNA content increased under the stimulation of BMP-2/7 (P0.05).ALP ac-tivity was higher by the induction of BMP-2/7 than in OMalone and PM(P<0.05).More mineraliza-tion deposition and more expressions of osteoblast-related genes such as Runx2,ALP,COL-1 A1 and OC were determined in the experimental group at different time points (P<0.05).HE staining showed that, in the test group and OM control group,the extracellular matrix (ECM)with eosinophilic staining were observed

  12. Kinetic performance and energy profile in a roller coaster electron transfer chain: a study of modified tetraheme-reaction center constructs. (United States)

    Alric, Jean; Lavergne, Jérôme; Rappaport, Fabrice; Verméglio, André; Matsuura, Katsumi; Shimada, Keizo; Nagashima, Kenji V P


    In many electron-transfer proteins, the arrangement of cofactors implies a succession of uphill and downhill steps. The kinetic implications of such arrangements are examined in the present work, based on a study of chimeric photosynthetic reaction centers obtained by expressing the tetraheme subunit from Blastochloris viridis in another purple bacterium, Rubrivivax gelatinosus. Site-directed mutations of the environment of heme c559, which is the immediate electron donor to the primary donor P, induced modifications of this heme's midpoint potential over a range of 400 mV. This resulted in shifts of the apparent midpoint potentials of the neighboring carriers, yielding estimates of the interactions between redox centers. At both extremities of the explored range, the energy profile of the electron-transfer chain presented an additional uphill step, either downstream or upstream from c559. These modifications caused conspicuous changes of the electron-transfer rate across the tetraheme subunit, which became approximately 100-fold slower in the mutants where the midpoint potential of c559 was lowest. A theoretical analysis of the kinetics is presented, predicting a displacement of the rate-limiting step when lowering the potential of c559. A reasonable agreement with the data was obtained when combining this treatment with the rates predicted by electron transfer theory for the individual rate constants.

  13. Role of ERalpha-ERRalpha Heterodimers in Tamoxifen-Resistant Breast Cancers (United States)


    were grown at 37 C with 5% CO2 for forty-eight hours, after which they were lysed in Freedman buffer [50 mM Tris, pH 7.5; 150 mM NaCl; 1% Nonidet P - 40 ...Biomarkers of Aggressive Breast Cancer. DOD-BCRP Era of Hope Conference, Orlando, FL, August, 2011. Mertz, J. E. Kraus, R. J., and Lillios, N. P ...nitroblue tetrazolium; HRP, horseradish peroxidas 1-piperazineethanesulfonic acid; DTT, dithiothreitol; cipitation; DAPI, 40 ,6-diamidino-2

  14. Controlling the self-assembly of protein polymers via heterodimer-forming modules

    NARCIS (Netherlands)

    Domeradzka, Natalia Eliza


    Supramolecular assemblies formed by protein polymers are attractive candidates for future biomaterials. Ideally, one would like to be able to define the nanostructure, in which the protein polymers should self-assemble, and then design protein polymer sequences that assemble exactly into such nanost

  15. The G protein-coupled receptor heterodimer network (GPCR-HetNet) and its hub components. (United States)

    Borroto-Escuela, Dasiel O; Brito, Ismel; Romero-Fernandez, Wilber; Di Palma, Michael; Oflijan, Julia; Skieterska, Kamila; Duchou, Jolien; Van Craenenbroeck, Kathleen; Suárez-Boomgaard, Diana; Rivera, Alicia; Guidolin, Diego; Agnati, Luigi F; Fuxe, Kjell


    G protein-coupled receptors (GPCRs) oligomerization has emerged as a vital characteristic of receptor structure. Substantial experimental evidence supports the existence of GPCR-GPCR interactions in a coordinated and cooperative manner. However, despite the current development of experimental techniques for large-scale detection of GPCR heteromers, in order to understand their connectivity it is necessary to develop novel tools to study the global heteroreceptor networks. To provide insight into the overall topology of the GPCR heteromers and identify key players, a collective interaction network was constructed. Experimental interaction data for each of the individual human GPCR protomers was obtained manually from the STRING and SCOPUS databases. The interaction data were used to build and analyze the network using Cytoscape software. The network was treated as undirected throughout the study. It is comprised of 156 nodes, 260 edges and has a scale-free topology. Connectivity analysis reveals a significant dominance of intrafamily versus interfamily connections. Most of the receptors within the network are linked to each other by a small number of edges. DRD2, OPRM, ADRB2, AA2AR, AA1R, OPRK, OPRD and GHSR are identified as hubs. In a network representation 10 modules/clusters also appear as a highly interconnected group of nodes. Information on this GPCR network can improve our understanding of molecular integration. GPCR-HetNet has been implemented in Java and is freely available at

  16. Interactions of Nucleic Acid Bases with Temozolomide. Stacked, Perpendicular, and Coplanar Heterodimers. (United States)

    Kasende, Okuma Emile; Nziko, Vincent de Paul N; Scheiner, Steve


    Temozolomide (TMZ) was paired with each of the five nucleic acid bases, and the potential energy surface searched for all minima, in the context of dispersion-corrected density functional theory and MP2 methods. Three types of arrangements were observed, with competitive stabilities. Coplanar H-bonding structures, reminiscent of Watson-Crick base pairs were typically the lowest in energy, albeit by a small amount. Also very stable were perpendicular arrangements that included one or more H-bonds. The two monomers were stacked approximately parallel to one another in the third category, some of which contained weak and distorted H-bonds. Dispersion was found to be a dominating attractive force, largest for the stacked structures, and smallest for the coplanar dimers.

  17. The Role of BRCA1/BARD1 Heterodimers in the Mitosis-Interphase Transition (United States)


    Littlepage, L., Wu, H., and Ruderman, J. V. (2003). Aurora A, meiosis and mitosis. Biol Cell 96, 215-229. Deng, C. X., and Wang, R. H. (2003...mitosis. J. Cell Biol. 120, 947–957. Crane, R., Gadea, B., Littlepage, L., Wu, H., and Ruderman, J.V. (2003). Aurora A, meiosis and mitosis. Biol. Cell...and the mitotic state. Extract naturally arrested in metaphase of meiosis II (CSF-arrested extract) was prepared by crushing unfertilized eggs in

  18. The G Protein-Coupled Receptor Heterodimer Network (GPCR-HetNet and Its Hub Components

    Directory of Open Access Journals (Sweden)

    Dasiel O. Borroto-Escuela


    Full Text Available G protein-coupled receptors (GPCRs oligomerization has emerged as a vital characteristic of receptor structure. Substantial experimental evidence supports the existence of GPCR-GPCR interactions in a coordinated and cooperative manner. However, despite the current development of experimental techniques for large-scale detection of GPCR heteromers, in order to understand their connectivity it is necessary to develop novel tools to study the global heteroreceptor networks. To provide insight into the overall topology of the GPCR heteromers and identify key players, a collective interaction network was constructed. Experimental interaction data for each of the individual human GPCR protomers was obtained manually from the STRING and SCOPUS databases. The interaction data were used to build and analyze the network using Cytoscape software. The network was treated as undirected throughout the study. It is comprised of 156 nodes, 260 edges and has a scale-free topology. Connectivity analysis reveals a significant dominance of intrafamily versus interfamily connections. Most of the receptors within the network are linked to each other by a small number of edges. DRD2, OPRM, ADRB2, AA2AR, AA1R, OPRK, OPRD and GHSR are identified as hubs. In a network representation 10 modules/clusters also appear as a highly interconnected group of nodes. Information on this GPCR network can improve our understanding of molecular integration. GPCR-HetNet has been implemented in Java and is freely available at

  19. TASK-1 and TASK-3 may form heterodimers in human atrial cardiomyocytes. (United States)

    Rinné, Susanne; Kiper, Aytug K; Schlichthörl, Günter; Dittmann, Sven; Netter, Michael F; Limberg, Sven H; Silbernagel, Nicole; Zuzarte, Marylou; Moosdorf, Rainer; Wulf, Hinnerk; Schulze-Bahr, Eric; Rolfes, Caroline; Decher, Niels


    TASK-1 channels have emerged as promising drug targets against atrial fibrillation, the most common arrhythmia in the elderly. While TASK-3, the closest relative of TASK-1, was previously not described in cardiac tissue, we found a very prominent expression of TASK-3 in right human auricles. Immunocytochemistry experiments of human right auricular cardiomyocytes showed that TASK-3 is primarily localized at the plasma membrane. Single-channel recordings of right human auricles in the cell-attached mode, using divalent-cation-free solutions, revealed a TASK-1-like channel with a single-channel conductance of about 30pS. While homomeric TASK-3 channels were not found, we observed an intermediate single-channel conductance of about 55pS, possibly reflecting the heteromeric channel formed by TASK-1 and TASK-3. Subsequent experiments with TASK-1/TASK-3 tandem channels or with co-expressed TASK-1 and TASK-3 channels in HEK293 cells or Xenopus oocytes, supported that the 55pS channels observed in right auricles have electrophysiological characteristics of TASK-1/TASK-3 heteromers. In addition, co-expression experiments and single-channel recordings suggest that heteromeric TASK-1/TASK-3 channels have a predominant surface expression and a reduced affinity for TASK-1 blockers. In summary, the evidence for heteromeric TASK-1/TASK-3 channel complexes together with an altered pharmacologic response to TASK-1 blockers in vitro is likely to have further impact for studies isolating ITASK-1 from cardiomyocytes and for the development of drugs specifically targeting TASK-1 in atrial fibrillation treatment.

  20. Structural and biochemical characterization of the Cop9 signalosome CSN5/CSN6 heterodimer.

    Directory of Open Access Journals (Sweden)

    Melissa Birol

    Full Text Available The Cop9 signalosome complex (CSN regulates the functional cycle of the major E3 ubiquitin ligase family, the cullin RING E3 ubiquitin ligases (CRLs. Activated CRLs are covalently modified by the ubiquitin-like protein Nedd8 (neural precursor cell expressed developmentally down-regulated protein 8. CSN serves an essential role in myriad cellular processes by reversing this modification through the isopeptidase activity of its CSN5 subunit. CSN5 alone is inactive due to an auto-inhibited conformation of its catalytic domain. Here we report the molecular basis of CSN5 catalytic domain activation and unravel a molecular hierarchy in CSN deneddylation activity. The association of CSN5 and CSN6 MPN (for Mpr1/Pad1 N-terminal domains activates its isopeptidase activity. The CSN5/CSN6 module, however, is inefficient in CRL deneddylation, indicating a requirement of further elements in this reaction such as other CSN subunits. A hybrid molecular model of CSN5/CSN6 provides a structural framework to explain these functional observations. Docking this model into a published CSN electron density map and using distance constraints obtained from cross-linking coupled to mass-spectrometry, we find that the C-termini of the CSN subunits could form a helical bundle in the centre of the structure. They likely play a key scaffolding role in the spatial organization of CSN and precise positioning of the dimeric MPN catalytic core.

  1. Imaging evidence for endothelin ETA/ETB receptor heterodimers in isolated rat mesenteric resistance arteries

    DEFF Research Database (Denmark)

    Kapsokalyvas, Dimitrios; Schiffers, Paul M H; Maij, Nathan


    AIMS: In engineered cells, endothelin ETA and ETB receptors can heterodimerize. We tested whether this can also be observed in native tissue. MAIN METHODS: Rat mesenteric resistance arteries (rMRA) were maintained in organ culture for 24h to upregulate ETB-mediated contractions in addition...... to their normal ETA-mediated responses. They were then exposed to 100 nM linear ET-1 (ETB-agonist) labeled with Oregon Green 488 (OG488/L.-ET-1) and/or to 16nM intact ET-1 (ETA/ETB-agonist) labeled with the rhodamine dye TAMRA (TAMRA/ET-1). Two photon laser scanning microscopy (TPLSM) was used...

  2. Tunable plasmonic response of metallic nanoantennna heterodimer arrays modified by atomic-layer deposition (United States)

    Wambold, Raymond A.; Borst, Benjamin D.; Qi, Jie; Weisel, Gary J.; Willis, Brian G.; Zimmerman, Darin T.


    We present a systematic study of tunable, plasmon extinction characteristics of arrays of nanoscale antennas that have potential use as sensors, energy-harvesting devices, catalytic converters, in near-field optical microscopy, and in surface-enhanced spectroscopy. Each device is composed of a palladium triangular-prism antenna and a flat counter-electrode. Arrays of devices are fabricated on silica using electron-beam lithography, followed by atomic-layer deposition of copper. Optical extinction is measured by employing a broadband light source in a confocal, transmission arrangement. We characterize the plasmon resonance behavior by examining the dependence on device length, the gap spacing between the electrodes, material properties, and the device array density, all of which contribute in varying degrees to the measured response. We employ finite-difference time-domain simulations to demonstrate good qualitative agreement between experimental trends and theory and use scanning electron microscopy to correlate plasmonic extinction characteristics with changes in morphology.

  3. A heterodimer comprised of two bovine lactoferrin antimicrobial peptides exhibits powerful bactericidal activity against Burkholderia pseudomallei

    NARCIS (Netherlands)

    Puknun, A.; Bolscher, J.G.M.; Nazmi, K.; Veerman, E.C.I.; Tungpradabkul, S.; Wongratanacheewin, S.; Kanthawong, S.; Taweechaisupapong, S.


    Melioidosis is a severe infectious disease that is endemic in Southeast Asia and Northern Australia. Burkholderia pseudomallei, the causative agent of this disease, has developed resistance to an increasing list of antibiotics, demanding a search for novel agents. Lactoferricin and lactoferrampin ar

  4. The role of the vomeronasal organ in rattlesnake (Crotalus viridis oreganus) predatory behavior. (United States)

    Alving, W R; Kardong, K V


    During predatory behavior, rattlesnakes depend primarily upon thermal and visual cues to initially aim a strike. However, it has been hypothesized that prey-related odors sensed by the vomeronasal system act as releasing stimuli of the strike and that such vomodors are primary stimuli during poststrike trailing and swallowing of the envenomated rodent. To test this, northern Pacific rattlesnakes were rendered avomic by bilateral lesions of the vomeronasal nerves, and their vomic and avomic predatory behaviors were compared. Avomic rattlesnakes exhibited fewer strikes and complete elimination of trailing and swallowing behavior. These results support the hypothesis that vomodors sensed via the vomeronasal organ are capable of acting as releasing stimuli of selected rattlesnake predatory behaviors. Sensory input via the vomeronasal organ is important during prestrike/strike behavior, and it is a major route of sensory input during poststrike trailing and ingestion of envenomated prey.

  5. Tumours of reptiles 4. Multiple osteomas in the lizard Laceria viridis

    NARCIS (Netherlands)

    Stolk, A.


    Whereas in fishes several osteomas (Bell, 1793; Gervais, 1875; Bland-Sutton, 1885 ; Plehn, 1906 ; Schroeders, 1908 ; Fiebiger, 1909 ; Williamson, 1913 ; Beatti, 1916 ; Kazama, 1924 ; Sagawa, 1925; Williams, 1929; Takahashi, 1929; Thomas, 1932, 1933; Lucké and Schlumberger, not published, see the pub

  6. A novel DNase like compound that inhibits virus propagation from Asian green mussel, Perna viridis (Linn.)

    Digital Repository Service at National Institute of Oceanography (India)

    Iqbal, A.N.M.Z.; Khan, M.S.

    to be comparable to commercial (Sigma-Aldrich) enzyme, DNase I. Bioactive assays conducted to evaluate antimicrobial property, have shown that CME and PPC exclusively inhibit viral propagation. Nonetheless, CME & PPC have no effect on the propagation of bacteria (0...

  7. Burrow ventilation and associated porewater irrigation by the polychaete Marenzelleria viridis

    DEFF Research Database (Denmark)

    Quintana, Cintia Organo; Hansen, Tanja; Delefosse, Matthieu;


    Burrow ventilation of benthic infauna generates water currents that irrigate the interstices of the sediments surrounding the burrow walls. Such activities have associated effects on biogeochemical processes affecting ultimately important ecosystem processes. In this study, the ventilation and ir...

  8. Kontaminasi senyawa poliklorobifenil (PCB pada kerang hijau, Perna viridis dari Teluk Jakarta

    Directory of Open Access Journals (Sweden)

    Edward .


    Full Text Available Abstract. The objective of this research was to examine the contamination level of polychlorinated biphenyl compound in green mussels. Green mussels samples were collected in Jakarta Bay in March 2013. Polychlorinated biphenyl level were quantified by gas chromatography HP 5880 series II completely with Electron Capture Detector (ECD. The levels of polychlorinatedbiphenyl in small size mussels was 0.846 ppb, in medium size mussels was 0.854 ppb, and in biger size mussels was 2.018 ppb. These levels were lowercompared to the safe threshold value for seafood which in 2,000 ppb. Therefore the green mussels from Jakarta Bay is safe to consumpt. Keywords: Jakarta Bay; contamination; PCB; green Mussels Abstrak. Penelitian ini bertujuan untuk menentukan tingkat kontaminasi senyawa polikloro bifenil dalam kerang hijau. Contoh kerang hijau dikumpulkan di Teluk Jakarta pada bulan Maret 2013. Kadar polikloro bifenil diukur  dengan alat kromatografi gas HP 5880 series II, yang dilengkapi dengan detektor penangkap elektron (ECD. Kadar polikloro bifenil dalam kerang hijau ukuran kecil adalah 0,846 ppb, kerang ukuran sedang adalah 0,854 ppb dan kerang ukuran besar adalah 2,018 ppb. Kadar ini masih rendah bila dibandingkan dengan nilai ambang batas aman untuk makanan hasil laut yakni 2000 ppb. Hasil penelitian ini diharapkan dapat memberikan informasi kepada masyarakat apakah kerang hijau di Teluk Jakarta ini masih aman untuk dikonsumsi. Kata kunci: Teluk Jakarta; kontaminasi; PCB; kerang hijau

  9. Antioxidative potential of Perna viridis and its protective role against ROS induced lipidperoxidation and protein carbonyl

    Digital Repository Service at National Institute of Oceanography (India)

    Jena, K.B.; Jagtap, T.G.; Verlecar, X.N.

    . 29. Satoh, M.S., Jones, C.J., Wood, R.D. and Lindahl, T. (1993). DNA excision repair defect of xeroderma pigmentosum prevents removal of a class of oxygen free radical-induced base lesions. Proceedings of the National Academy of Sciences, USA, 90...

  10. Biochemical markers of oxidative stress in Perna viridis exposed to mercury and temperature

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    cumene-hydroperoxide as the substrate. The absorbance was recorded at 340 nm. Enzyme activity was expressed as nmol NADPH oxidized / min/ mg proteins using a molar extinction coefficient of 6.22 mM-1 cm-1. The activity of GR was assayed following... the rate of NADPH oxidation at 340 in the presence of GSSG [19]. Enzyme activity was expressed as nmol NADPH oxidized / min/ mg proteins using a molar extinction coefficient of 6.22 mM-1 cm-1. GST activity was measured according to Habig et al.[20...

  11. Application of oxidative stress indices in natural populations of Perna viridis as biomarker of environmental pollution

    Digital Repository Service at National Institute of Oceanography (India)

    Jena, K.B.; Verlecar, X.N.; Chainy, G.B.N.

    -hydro- peroxide as substrate (Paglia and Valentine, 1967). Absorbance was recorded at 340 nm, and enzyme activity was expressed as nmol NADPH oxidized/min/mg proteins, using a molar extinction coefficient of 6.22 mM C01 cm C01 . The activity of GR was assayed fol...- lowing the rate of NADPH oxidation at 340 nm in the presence of GSSG (Massey and Williams, 1965). Enzyme activity was ex- pressed as nmol NADPH oxidized/min/mg proteins using a molar extinction coefficient of 6.22 mM C01 cm C01 . Glutathione S...

  12. Biomarkers of petroleum contamination in the digestive gland of Perna viridis (L.)

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Desai, S.R.; Das, P.B.; Chainy, G.B.N.

    at 366 nm with the use of a molar absorption coeffi cient of 22,000 mol cm–1 and expressed as nmol mg protein–1. Alkaline unwinding assay Th e alkaline DNA unwinding assay was performed according to the method of Shugart with slight Biomarkers... mg protein–1 using a molar extinction coeffi cient of 6.22 mM–1 cm–1. Th e activity of GR was assayed according to the rate of NADPH oxidation at 340 nm in the presence of GSSG (35). Enzyme activity was expressed as nmol NADPH oxidized min–1 mg...

  13. Extract of Indian green mussel, Perna viridis (L.) shows inhibition of blood capillary formation in vitro

    Digital Repository Service at National Institute of Oceanography (India)

    Mirshahi, M.; Mirshahi, P.; Negro, S.; Soria, J.; Sreekumar, P.K.; Kotnala, S.; Therwath, A.; Chatterji, A.

    to the control. No. of capillary tubes formed/ visual field Control 5 mg/mL 1 mg/mL 0,2 mg/mL 0,04 mg/mL Concentrations of GM Crude (mg/mL) 100 80 60 40 20 0 2 Hrs 4 Hrs 6 Hrs Fig. 1: Dose and time dependant effects of the GM crude on the formation... of capillary tubes of human microvascular endothelial cells No. of junctions formed/ visual field Control 5 mg/mL 1 mg/mL 0,2 mg/mL 0,04 mg/mL Concentrations of GM Crude (mg/mL) 180 160 140 120 100 80 60 40 20 0 2 Hrs 4 Hrs 6 Hrs Fig. 2: The dose and time...

  14. Identification of lysozyme activity from two edible bivalves - Perna viridis (Linnaeus) and Meretrix casta (Chemnitz)

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, S.; Tanu; Chatterji, A.

    with the pathogen Vibrio tapetis. J. Invertebr. Pathol., 76, 63–69. Bachali, S., Jager, M., Hassanin, A., Schoentgen, F., Jolles, P., Fiala-Medioni, A. and Deutsch, J.S. (2002). Phylogenetic analysis of invertebrate lysozymes and the evolution of lysozyme... function. J. Mol. Evol., 54, 652–664. Bachali, S., Bailly, X., Jolles, J., Jolles, P. and Deutsch, J.S. (2004). The lysozyme of the starfish Asterias rubens. A paradygmatic type i lysozyme. Eur. J. Biochem., 271, 237-242. Chipman, D.M. and Sharon, N...

  15. DNA damage in male gonad cells of Green mussel (Perna viridis) upon exposure to tobacco products

    Digital Repository Service at National Institute of Oceanography (India)

    Nagarajappa; Ganguly, A.; Goswami, U.

    , 5 ? g, 10 ? g and 15 ? g of extract per ml of seawater. Each set of experiment comprised of 4 tanks out of which 3 were given the same treatment, and 4th one was kept as untreated control. Experiment was conducted in triplicates. Each glass tank..., expressed in SD and n=3). The experiments in all tanks for both the treatments were conducted for different durations of time varying from 0-16 days, water changed twice a day and treatment was given accordingly. On each even number day i.e. day 2, 4, 6...

  16. Proximate biochemical composition and caloric potential in the raft-grown green mussel Perna viridis

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Parulekar, A.H.

    . g sup(-1). The maximum value of total energy was found to coincide with higher values of protein, indicating significant contribution by protein to the total energy. The relationship between biochemical constituents and spawning cycle is discussed....

  17. Cytogenetic studies in green mussel, Perna viridis (Mytiloida: Pteriomorphia), from West Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Iqbal, A.N.M.Z.; Khan, M.S.; Goswami, U.

    study of interspecific hybrids of Ashmunella (Mollusca: Pulmonata: Polygyridae). I. Ashmunella proxima X Ashmunella lenticula F1 hybrids. Mal- acologia 25:413–426 Burch JB (1965) Chromosome number and systematics in euthyneu- ran snails. In: Proceedings...

  18. Proximity-Directed Labeling Reveals a New Rapamycin-Induced Heterodimer of FKBP25 and FRB in Live Cells (United States)


    Mammalian target of rapamycin (mTOR) signaling is a core pathway in cellular metabolism, and control of the mTOR pathway by rapamycin shows potential for the treatment of metabolic diseases. In this study, we employed a new proximity biotin-labeling method using promiscuous biotin ligase (pBirA) to identify unknown elements in the rapamycin-induced interactome on the FK506-rapamycin binding (FRB) domain in living cells. FKBP25 showed the strongest biotin labeling by FRB–pBirA in the presence of rapamycin. Immunoprecipitation and immunofluorescence experiments confirmed that endogenous FKBP25 has a rapamycin-induced physical interaction with the FRB domain. Furthermore, the crystal structure of the ternary complex of FRB–rapamycin–FKBP25 was determined at 1.67-Å resolution. In this crystal structure we found that the conformational changes of FRB generate a hole where there is a methionine-rich space, and covalent metalloid coordination was observed at C2085 of FRB located at the bottom of the hole. Our results imply that FKBP25 might have a unique physiological role related to metallomics in mTOR signaling. PMID:27610411


    Akar, H Haluk; Yıldız, Mikdat; Sevinc, Eylem; Sokucu, Semra


    Antecedentes y objetivo: el marcador genético esencial relacionado con la enfermedad celíaca (CD) es la molécula HLA-DQ2 codificada por los genes DQA1*0501 y DQB1*0201. El objetivo de este estudio es evaluar el efecto de estos alelos en las características clínicas, serológicas e histológicas de los niños turcos que tienen la enfermedad celíaca. Material y métodos: nosotros hemos dividido los 36 pacientes celíacos en 4 grupos de acuerdo con su genotipo HLA-DQ2 basado en la presencia o la ausencia de los alelos DQA1*0501 y DQB1*0201. Grupo 1: 4 pacientes que no tenían los alelos HLA-DQ2A1*0501 y DQ2B1*0201; Grupo 2: 12 pacientes que tenían por lo menos uno de estos alelos con un estado heterocigoto; Grupo 3: 12 pacientes que tenián ambos alelos con un estado heterocigoto; Grupo 4: 8 pacientes que tenían ambos alelos con un estado heterocigoto. Nosotros hemos comparado los grupos de acuerdo con las características clínicas, serológicas, histológicas y bioquímicas. Resultados: no había significación estadística entre los grupos por edad, índice de masa corporal, (IMC), peso por altura y aparición de síntomas. Sin embargo, en los grupos 3 y 4 comparados con los grupos 1 y 2 se observaron unas diferencias menores en IMC y anticuerpos antigliadina (AGA), sin una significación estadística. De acuerdo con los antiendomisios (EMA), la puntuación Marsh, las presentaciones clínicas y los valores hematológicos y bioquímicos, no había una significación estadística entre los grupos sin estreñimiento respecto a los valores más altos observados en el grupo 4 sin significación estadística. Se detectó hipertiroidismo en un paciente (25%) del grupo de carga genética más baja (grupo 1) con significación estadística (p < 0,046). El resultado: en este estudio, las pequeñas diferencias que se encontraton entre los grupos no dilucidaron el impacto de los alelos HLA-DQ2 A1*0501 y DQ2B1*0201 en las manifectaciones clínicas, serológicas y de laboratorio de los pacientes celíacos. Se necesitan nuevos estudios para evaluar el efecto de los alelos HLA y otros polimorfismos genéticos en los resultados sobre la enfermedad celíaca en los niños.

  20. 青霉素G酰化酶的亚基重组%Cross-species heterodimers of penicillin G acylase

    Institute of Scientific and Technical Information of China (English)

    张燕; 杨晟


    青霉素G酰化酶在半合成β-内酰胺类抗生素工业中催化关键反应.将来源于Esherichia coli的α亚基分别与Kluyvera citrophila,Providencia rettgeri,Alcaligenes faecalis的β亚基重组得到三种杂合酶,杂合酶表达量随野生型PGA同源性的减小而降低,E.coli和A.Iaecalis氨基酸序列的相同性低至41%,其杂合酶仍然具有水解3-苯乙酰胺-6-硝基苯甲酸的活力.

  1. Preferential production of the IL-12(p40)/IL-23(p19) heterodimer by dendritic cells from human newborns. (United States)

    Vanden Eijnden, Serge; Goriely, Stanislas; De Wit, Dominique; Goldman, Michel; Willems, Fabienne


    Human newborns present impaired T helper type 1 cell responses, associated with a defect in the synthesis of IL-12 by dendritic cells (DC). IL-23 is a heterodimeric cytokine structurally related to IL-12, implicated in protective and autoimmune responses. We recently showed that upon activation neonatal T cells up-regulate a functional IL-23 receptor and that this cytokine polarizes the differentiation of naive T cells. We therefore investigated the capacity of neonatal DC to secrete IL-23. Lipopolysaccharide (LPS) stimulation induced the transcription of IL-23(p19) mRNA in both adult and neonatal DC, in sharp contrast to the repressed IL-12(p35) gene expression observed in neonatal cells. In comparison to adult DC, neonatal DC produced similar levels of IL-23 protein, in reponse to Toll-like receptor (TLR)-2- and TLR-3 ligands, and higher levels in response to TLR-4- or TLR-8 ligands. The same profile was observed in neonatal mononuclear cells. The supernatant of LPS-stimulated DC induced the secretion of IL-17 by polyclonally activated neonatal CD8(+) T cells, confirming the IL-23 bioactivity. Altogether, these observations strongly suggest that IL-23 could play a role in the immune system of human newborns. In particular, a functional IL-23/IL-17 axis might compensate a suboptimal IL-12/IFN-gamma pathway in early life.

  2. Structures of self-assembled amphiphilic peptide-heterodimers: effects of concentration, pH, temperature and ionic strength

    KAUST Repository

    Luo, Zhongli


    The amphiphilic double-tail peptides AXG were studied regarding secondary structure and self-assembly in aqueous solution. The two tails A = Ala 6 and G = Gly6 are connected by a central pair X of hydrophilic residues, X being two aspartic acids in ADG, two lysines in AKG and two arginines in ARG. The peptide AD (Ala6Asp) served as a single-tail reference. The secondary structure of the four peptides was characterized by circular dichroism spectroscopy under a wide range of peptide concentrations (0.01-0.8 mM), temperatures (20-98 °C), pHs (4-9.5) and ionic strengths. In salt-free water both ADG and AD form a β-sheet type of structure at high concentration, low pH and low temperature, in a peptide-peptide driven assembly of individual peptides. The transition has a two-state character for ADG but not for AD, which indicates that the added tail in ADG makes the assembly more cooperative. By comparison the secondary structures of AKG and ARG are comparatively stable over the large range of conditions covered. According to dynamic light scattering the two-tail peptides form supra-molecular aggregates in water, but high-resolution AFM-imaging indicate that ordered (self-assembled) structures are only formed when salt (0.1 M NaCl) is added. Since the CD-studies indicate that the NaCl has only a minor effect on the peptide secondary structure we propose that the main role of the added salt is to screen the electrostatic repulsion between the peptide building blocks. According to the AFM images ADG and AKG support a correlation between nanofibers and a β-sheet or unordered secondary structure, whereas ARG forms fibers in spite of lacking β-sheet structure. Since the AKG and ARG double-tail peptides self-assemble into distinct nanostructures while their secondary structures are resistant to environment factors, these new peptides show potential as robust building blocks for nano-materials in various medical and nanobiotechnical applications. © 2010 The Royal Society of Chemistry.

  3. Cultivation of green mussel, Perna viridis L., on a floating raft in an estuary along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Ansari, Z.A.; Parulekar, A.H.

    . Consistently high growth rate was recorded for up to 164 days of culture (P = 21.32 kg m sup(-1); B = 10.87 kg m sup(-1)). Thereafter, the production increased, but the growth rate was low (P = 33.51 kg m sup(-1) year sup(-1); B = 21.32 kg m sup(-1) year sup(-1...

  4. Seasonal variation of oxidative biomarkers in gills and digestive gland of green-lipped mussel Perna viridis from Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Chainy, G.B.N.

    . Enzyme activity was expressed as nmol NADPH oxidized / min / mg proteins using a molar extinction coefficient of 6.22 mM -1 cm -1 . The activity of GR was assayed following the rate of NADPH oxidation at 340 nm in the presence of GSSG (Massy... and Williams, 1965). Enzyme activity was expressed as nmol NADPH oxidized / min/ mg proteins using a molar extinction coefficient of 6.22 mM -1 cm -1 . GST activity was measured according to Habig et al. (1974) using CDNB as a substrate. The change...

  5. Biometric and morphometric studies of Perna viridis and Perna indica along the southwest coast of India: a statistical approach

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, K.V.; Nair, M.; DileepKumar, R.; Vijayan, M.

    from which the species samples are collected. Statistical techniques such as 2 Way ANOVA and student’s t test can identify the differences between their characteristics based on allometry. Canonical discriminate analysis is applied to discriminate... APPROACH E-mail: (Jayalakshmy KV) Peer review under responsibility of Journal of Experimental Biology and Agricultural Sciences. * Corresponding author Journal of Experimental Biology and Agricultural Sciences, September...

  6. Protein (Cyanobacteria): 438434 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)


  7. Mechanisms for dominance: Adh heterodimer formation in heterozygotes between ENU or x-ray induced null alleles and normal alleles in drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, J.C.; Lee, W.R.; Chang, S.H.; Silverman, H. (Louisiana State Univ., Baton Rouge (United States))


    To study mechanisms for dominance of phenotype, eight ENU- and four x-ray-induced mutations at the alcohol dehydrogenase (Adh) locus were analyzed for partial dominance in their interaction with normal alleles. All ENU and one of the x-ray mutations were single base substitutions; the other three x-ray mutations were 9-21 base deletions. All but one of the 12 mutant alleles were selected for this study because they produced detectable mutant polypeptides, but seven of the 11 producing a peptide could not form dimers with the normal peptide and the enzyme activity of heterozygotes was about half that of normal homozygotes. Four mutations formed dimers with a decreased catalytic efficiency and two of these were near the limit of detectability; these two also inhibited the formation of normal homodimers. The mutant alleles therefore show multiple mechanisms leading to partial enzyme expression in heterozygotes and a wide range of dominance ranging from almost complete recessive to nearly dominant. All amino acid changes in mutant peptides that form dimers are located between amino acids 182 and 194, so this region is not critical for dimerization. It may, however, be an important surface domain for catalyzation. 34 refs., 8 figs., 2 tabs.

  8. Free fatty acids repress small heterodimer partner (SHP) activation and adiponectin counteracts bile acid-induced liver injury in superobese patients with nonalcoholic steatohepatitis

    NARCIS (Netherlands)

    Bechmann, Lars P.; Kocabayoglu, Peri; Sowa, Jan-Peter; Sydor, Svenja; Best, Jan; Schlattjan, Martin; Beilfuss, Anja; Schmitt, Johannes; Hannivoort, Rebekka A.; Kilicarslan, Alpaslan; Rust, Christian; Berr, Frieder; Tschopp, Oliver; Gerken, Guido; Friedman, Scott L.; Geier, Andreas; Canbay, Ali


    Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in industrialized countries and may proceed to steatohepatitis (NASH). Apoptosis and free fatty acid (FFA)-induced lipotoxicity are important features of NASH pathogenesis. We have shown a hepatoprotective effect of adiponecti

  9. Rexinoid Bexarotene Modulates Triglyceride but not Cholesterol Metabolism via Gene-Specific Permissivity of the RXR/LXR Heterodimer in the Liver

    DEFF Research Database (Denmark)

    Lalloyer, Fanny; Pedersen, Thomas Åskov; Gross, Barbara;


    OBJECTIVE: Bexarotene (Targretin) is a clinically used antitumoral agent which exerts its action through binding to and activation of the retinoid-X-receptor (RXR). The most frequent side-effect of bexarotene administration is an increase in plasma triglycerides, an independent risk factor...

  10. HrpG and HrpV proteins from the Type III secretion system of Erwinia amylovora form a stable heterodimer. (United States)

    Gazi, Anastasia D; Charova, Spyridoula; Aivaliotis, Michalis; Panopoulos, Nicholas J; Kokkinidis, Michael


    Bacterial type III secretion systems (T3SSs) are specialized multicomponent nanomachines that mediate the transport of proteins either to extracellular locations or directly into eukaryotic host cell cytoplasm. Erwinia amylovora, the main agent of rosaceous plants fireblight disease, employs an Hrp/Hrc1 T3SS to accomplish its pathogenesis. The regulatory network that controls the activation of this T3SS is largely unknown in E. amylovora. However, in Pseudomonas syringae pathovars, the HrpG/HrpV complex has been shown to directly regulate the activity of transcription factor HrpS and consequently the upregulation of the Hrp/Hrc1 T3SS related genes. In this work, we report the successful recombinant production and purification of a stable E. amylovora HrpG/HrpV complex, using pPROpET, a bicistronic expression vector. Furthermore, we present the first solution structure of this complex based on small-angle X-ray scattering data.

  11. Solution study of the Escherichia coli DNA polymerase III clamp loader reveals the location of the dynamic ψχ heterodimer

    Directory of Open Access Journals (Sweden)

    Farzaneh Tondnevis


    Full Text Available Several X-ray crystal structures of the E. coli core clamp loader containing the five core (δ′, δ, and three truncated γ subunits have been determined, but they lack the ψ and χ subunits. We report the first solution structure of the complete seven-subunit clamp loader complex using small angle X-ray scattering. This structure not only provides information about the location of the χ and ψ subunits but also provides a model of the dynamic nature of the clamp loader complex.

  12. Oncogenic mutations weaken the interactions that stabilize the p110α-p85α heterodimer in phosphatidylinositol 3-kinase α. (United States)

    Echeverria, Ignacia; Liu, Yunlong; Gabelli, Sandra B; Amzel, L Mario


    Phosphatidylinositol 3-kinase (PI3K) α is a heterodimeric lipid kinase that catalyzes the conversion of phosphoinositol-4,5-bisphosphate to phosphoinositol-3,4,5-trisphosphate. The PI3Kα signaling pathway plays an important role in cell growth, proliferation, and survival. This pathway is activated in numerous cancers, where the PI3KCA gene, which encodes for the p110α PI3Kα subunit, is mutated. Its mutation often results in gain of enzymatic activity; however, the mechanism of activation by oncogenic mutations remains unknown. Here, using computational methods, we show that oncogenic mutations that are far from the catalytic site and increase the enzymatic affinity destabilize the p110α-p85α dimer. By affecting the dynamics of the protein, these mutations favor the conformations that reduce the autoinhibitory effect of the p85α nSH2 domain. For example, we determined that, in all of the mutants, the nSH2 domain shows increased positional heterogeneity as compared with the wild-type, as demonstrated by changes in the fluctuation profiles computed by normal mode analysis of coarse-grained elastic network models. Analysis of the interdomain interactions of the wild-type and mutants at the p110α-p85α interface obtained with molecular dynamics simulations suggest that all of the tumor-associated mutations effectively weaken the interactions between p110α and p85α by disrupting key stabilizing interactions. These findings have important implications for understanding how oncogenic mutations change the conformational multiplicity of PI3Kα and lead to increased enzymatic activity. This mechanism may apply to other enzymes and/or macromolecular complexes that play a key role in cell signaling.

  13. Conicasterol E, a Small Heterodimer Partner Sparing Farnesoid X Receptor Modulator Endowed with a Pregnane X Receptor Agonistic Activity, from the Marine Sponge Theonella swinhoei


    V. Sepe; Ummarino, R.; D'Auria, M. V.; M. G. Chini; Bifulco, G.; Renga, B; D'Amore, C.; Debitus, Cécile; Fiorucci, S.; Zampella, A.


    We report the isolation and pharmacological characterization of conicasterol E isolated from the marine sponge Theonella swinhoei. Pharmacological characterization of this steroid in comparison to CDCA, a natural FXR ligand, and 6-ECDCA, a synthetic FXR agonist generated by an improved synthetic strategy, and rifaximin, a potent PXR agonist, demonstrated that conicasterol E is an FXR modulator endowed with PXR agonistic activity. Conicasterol E induces the expression of genes involved in bile...

  14. Pan-HER - an antibody mixture targeting EGFR, HER2, and HER3 abrogates preformed and ligand-induced EGFR homo- and heterodimers

    DEFF Research Database (Denmark)

    Ellebaek, Sofie; Pedersen, Susanne Brix; Grandal, Michael


    Abs is development of acquired resistance through mechanisms such as alterated receptor dimerization patterns and dependencies. Pan-HER is a mixture of six mAbs simultaneously targeting epidermal growth factor receptor (EGFR), HER2, and HER3 with two mAbs against each receptor. Pan-HER has previously demonstrated....... The effect of Pan-HER on cell proliferation and HER-family receptor degradation was superior to treatment with single mAbs targeting either single receptor, and similar to targeting a single receptor with two non-overlapping antibodies. Furthermore, changes in EGFR-dimerization patterns after treatment......-HER and the EGFR-targeting mAb mixture also blocked EGF-binding and thereby ligand-induced changes in EGFR-dimerization levels. These results suggest that Pan-HER reduces the cellular capability to switch HER-dependency and dimerization pattern in response to treatment and thus hold promise for future clinical...

  15. Pan-HER-An antibody mixture targeting EGFR, HER2 and HER3 abrogates preformed and ligand-induced EGFR homo- and heterodimers. (United States)

    Ellebaek, Sofie; Brix, Susanne; Grandal, Michael; Lantto, Johan; Horak, Ivan D; Kragh, Michael; Poulsen, Thomas Tuxen


    The human epidermal growth factor receptor (HER)-family is involved in development of many epithelial cancers. Therefore, HER-family members constitute important targets for anti-cancer therapeutics such as monoclonal antibodies (mAbs). A limitation to the success of single HER-targeting mAbs is development of acquired resistance through mechanisms such as alterted receptor dimerization patterns and dependencies. Pan-HER is a mixture of six mAbs simultaneously targeting epidermal growth factor receptor (EGFR), HER2 and HER3 with two mAbs against each receptor. Pan-HER has previously demonstrated broader efficacy than targeting single or dual receptor combinations also in resistant settings. In light of this broad efficacy, we decided to investigate the effect of Pan-HER compared with single HER-targeting with single and dual mAbs on HER-family cross-talk and dimerization focusing on EGFR. The effect of Pan-HER on cell proliferation and HER-family receptor degradation was superior to treatment with single mAbs targeting either single receptor, and similar to targeting a single receptor with two non-overlapping antibodies. Furthermore, changes in EGFR-dimerization patterns after treatment with Pan-HER were investigated by in situ proximity ligation assay and co-immunoprecipitation, demonstrating that Pan-HER and the EGFR-targeting mAb mixture efficiently down-regulate basal EGFR homo- and heterodimerization in two tested cell lines, whereas single mAbs had limited effects. Pan-HER and the EGFR-targeting mAb mixture also blocked EGF-binding and thereby ligand-induced changes in EGFR-dimerization levels. These results suggest that Pan-HER reduces the cellular capability to switch HER-dependency and dimerization pattern in response to treatment and thus hold promise for future clinical development of Pan-HER in resistant settings.

  16. Different features of the MHC class I heterodimer have evolved at different rates. Chicken B-F and beta 2-microglobulin sequences reveal invariant surface residues

    DEFF Research Database (Denmark)

    Kaufman, J; Andersen, R; Avila, D;


    of small exons in the cytoplasmic region. The cDNA sequences were compared to turkey beta 2m, the apparent allele B-F12 alpha and other vertebrate homologs, using the 2.6 A structure of the human HLA-A2 molecule as a model. Both chicken alpha 1 and alpha 2 domains resemble mammalian classical class I...

  17. Placenta growth factor-1 antagonizes VEGF-induced angiogenesis and tumor growth by the formation of functionally inactive PIGF-1/VEGF heterodimers

    DEFF Research Database (Denmark)

    Eriksson, A.; Cao, R.; Pawliuk, R.;


    , the biological function of its related homolog, placenta growth factor (PlGF), is poorly understood. Here we demonstrate that PlGF-1, an alternatively spliced isoform of the PlGF gene, antagonizes VEGF-induced angiogenesis when both factors are coexpressed in murine fibrosarcoma cells. Overexpression of PlGF-1...

  18. Changes in Binding Motif of Protonated Heterodimers Containing Valine and Amines Investigated Using IRMPD Spectroscopy between 800 and 3700 cm(-1) and Theory

    NARCIS (Netherlands)

    O' Brien, J. T.; Prell, J. S.; Steill, J. D.; Oomens, J.; Williams, E. R.


    Proton-bound dimers consisting of valine and basic primary and secondary amines of varying gas-phase basicity (GB) were investigated using infrared multiple photon dissociation (IRMPD) spectroscopy between 800 and 3700 cm(-1), collisionally activated dissociation, and theory. The low-energy dissocia

  19. The light-harvesting complexes of higher-plant Photosystem I : Lhca1/4 and Lhca2/3 form two red-emitting heterodimers

    NARCIS (Netherlands)

    Wientjes, Emilie; Croce, Roberta


    The outer antenna of higher-plant PSI (Photosystem I) is composed of four complexes [Lhc (light-harvesting complex) al-Lhca4] belonging to the light-harvesting protein family. Difficulties in their purification have so far prevented the determination of their properties and most of the knowledge abo

  20. Toxicity and Traces of Hg, Pb and Cd in the Hepatopancreas, Gills and Muscles of Perna viridis from Jakarta Bay, Indonesia. (United States)

    Irnidayanti, Y


    Heavy metals contamination on the coast of Jakarta Bay has led to the level of pollution and can cause toxicity to organisms living in the sea, i.e., green mussels. Green mussels have the ability to detoxify metals entering their bodies. Their ability to accumulate metals is higher than other aquatic animals. This is due to their sedentary life which prevents them from avoiding the effects of pollution and their high tolerance to certain metals. The high concentration of metal content would be toxic to the cell because metal ions can act as oxidants and bind to organic and protein molecules. The results of the study showed that traces of heavy metals were detected in the hepatopancreas, gills, muscles and gonads organs of the mussels living in the waters of Muara Angke. Lead (Pb) and cadmium (Cd) were found in all four organs, while mercury (Hg) was not detected in the muscles. Traces of Hg and Cd were not detected in hepatopancreas, gills, muscles and gonads of green mussels in Panimbang, while Pb was detected by 0.00 1 in the male gonads and 0.01 in hepatopancreas. The concentration of Pb in the male gonads are still below the acceptable limit and concentration of Pb in the hepatopancreas is relatively equivalent to the acceptable limit. Metal detection in the organs above shows that the Muara Angke waters tend to be polluted and have an impact on the mussels weight loss as a result of heavy metal toxicity.

  1. Seasonal variation of major elements (Ca, Mg) and trace metals (Fe, Cu, Zn, Mn) and cultured mussel Perna viridis L. and seawater in the Dona Paula Bay, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Parulekar, A.H.

    The major elements and trace metals were analysed from nussel tissue and the seawater taken from three depths (0, 5 and 9 meters) from the culture site. Range of variation in Ca, Mg, Fe, Cu, Zn and Mn were 226-399; 708-1329; 0.005-0.084; BDL-0...

  2. 翡翠贻贝气调保鲜包装研究%Study on the Modified Atmosphere Packaging of Green Mussels(Perna Viridis)

    Institute of Scientific and Technical Information of China (English)

    徐航; 程裕东; 雷桥; 曹婕


    采用涂布聚偏二氯乙烯的聚酯与聚乙烯复合薄膜袋(KPET/PE)气调包装翡翠贻贝,混合气体包括:CO2、O2和N2.选用5组气体配比(A:V(75%O2)/V(25%N2);B:V(50%O2)/V(50%N2);C:V(20%O2)/V(30%CO2)/V(50%N2);D:V(10%O2)/V(50%CO2)/V(40%N2);E:空气)进行包装并贮藏在5℃以下.在贮藏期间测定包装袋内气体浓度变化、需氧菌总数、TVBN和pH值,研究在不同气调比例包装条件下,翡翠贻贝的品质变化.实验结果表明:在贮藏温度为5℃条件下采用气调包装的样品,其需氧菌总数和TVBN等指标明显优于空气对照组.在5组气体比例中,以V(O2)∶V(CO2)∶V(N2)=10%∶50%∶40%的配气比例包装的保鲜效果最佳,其贮藏期比对照组空气包装延长3~8 d.


    Directory of Open Access Journals (Sweden)

    I Nyoman Radiarta


    Full Text Available Green mussel is one of important species cultured in Lada Bay, Pandeglang. To provide a necessary guidance regarding green mussel mariculture development, finding suitable site is an important step. This study was conducted to identify suitable site for green mussel mariculture development using geographic information system (GIS based models. Seven important parameters were grouped into two submodels, namely environmental (water temperature, salinity, suspended solid, dissolve oxygen, and bathymetry and infrastructural (distance to settlement and pond aquaculture. A constraint data was used to exclude the area from suitability maps that cannot be allowed to develop green mussel mariculture, including area of floating net fishing activity and area near electricity station. Analyses of factors and constraints indicated that about 31% of potential area with bottom depth less than 25 m had the most suitable area. This area was shown to have an ideal condition for green mussel mariculture in this study region. This study shows that GIS model is a powerful tool for site selection decision making. The tool can be a valuable tool in solving problems in local, regional, and/or continent areas.

  4. A vertebrate reproductive system involving three ploidy levels: hybrid origin of triploids in a contact zone of diploid and tetraploid palearctic green toads (Bufo viridis subgroup). (United States)

    Stöck, Matthias; Ustinova, Jana; Lamatsch, Dunja K; Schartl, Manfred; Perrin, Nicolas; Moritz, Craig


    The rise and consequences of polyploidy in vertebrates, whose origin was associated with genome duplications, may be best studied in natural diploid and polyploid populations. In a diploid/tetraploid (2n/4n) geographic contact zone of Palearctic green toads in northern Kyrgyzstan, we examine 4ns and triploids (3n) of unknown genetic composition and origins. Using mitochondrial and nuclear sequence, and nuclear microsatellite markers in 84 individuals, we show that 4n (Bufo pewzowi) are allopolyploids, with a geographically proximate 2n species (B. turanensis) being their maternal ancestor and their paternal ancestor as yet unidentified. Local 3n forms arise through hybridization. Adult 3n mature males (B. turanensis mtDNA) have 2n mothers and 4n fathers, but seem distinguishable by nuclear profiles from partly aneuploid 3n tadpoles (with B. pewzowi mtDNA). These observations suggest multiple pathways to the formation of triploids in the contact zone, involving both reciprocal origins. To explain the phenomena in the system, we favor a hypothesis where 3n males (with B. turanensis mtDNA) backcross with 4n and 2n females. Together with previous studies of a separately evolved, sexually reproducing 3n lineage, these observations reveal complex reproductive interactions among toads of different ploidy levels and multiple pathways to the evolution of polyploid lineages.

  5. Strong reproductive barriers in a narrow hybrid zone of West-Mediterranean green toads (Bufo viridis subgroup with Plio-Pleistocene divergence

    Directory of Open Access Journals (Sweden)

    Perrin Nicolas


    Full Text Available Abstract Background One key question in evolutionary biology deals with the mode and rate at which reproductive isolation accumulates during allopatric speciation. Little is known about secondary contacts of recently diverged anuran species. Here we conduct a multi-locus field study to investigate a contact zone between two lineages of green toads with an estimated divergence time of 2.7 My, and report results from preliminary experimental crosses. Results The Sicilian endemic Bufo siculus and the Italian mainland-origin B. balearicus form a narrow hybrid zone east of Mt. Etna. Despite bidirectional mtDNA introgression over a ca. 40 km North-South cline, no F1 hybrids could be found, and nuclear genomes display almost no admixture. Populations from each side of the contact zone showed depressed genetic diversity and very strong differentiation (FST = 0.52. Preliminary experimental crosses point to a slightly reduced fitness in F1 hybrids, a strong hybrid breakdown in backcrossed offspring (F1 x parental, with very few reaching metamorphosis and a complete and early mortality in F2 (F1 x F1. Conclusion Genetic patterns at the contact zone are molded by drift and selection. Local effective sizes are reduced by the geography and history of the contact zone, B. balearicus populations being at the front wave of a recent expansion (late Pleistocene. Selection against hybrids likely results from intrinsic genomic causes (disruption of coadapted sets of genes in backcrosses and F2-hybrids, possibly reinforced by local adaptation (the ranges of the two taxa roughly coincide with the borders of semiarid and arid climates. The absence of F1 in the field might be due to premating isolation mechanisms. Our results, show that these lineages have evolved almost complete reproductive isolation after some 2.7 My of divergence, contrasting sharply with evidence from laboratory experiments that some anuran species may still produce viable F1 offspring after > 20 My of divergence.

  6. Zwei neue Apogonien von den Philippinen

    NARCIS (Netherlands)

    Heller, K.M.


    Fulva, parce viridi-metallico micans, supra glabra, subtusatro-viridis, squamulis setiformibus albis sat parce tecta; clypeo antice truncato, creberrime et quam fronte fortius punctato; prothorace aliquid remote punctato, angulis anticis acutis; scutello subtiliter punctato, interdum laevi; elytris

  7. Chrysobothris rutilicuspis, nova species Buprestidarum

    NARCIS (Netherlands)

    Heller, K.M.


    Ex affinitate Ch. insolatae Deyr. et perplexae Deyr. — ♀. Caput fronte impressa, circulatim striata, supra impressionem ignita, vertice viridi. Thorax viridis, lateribus late ignitus, transverse striolatus et sat dense interpunctatus, margine basali medio lobo apice truncato. Scutellum acute triangu

  8. Protein (Cyanobacteria): 390233 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)


  9. ADH Heterodimer Formation in Heterozygotes between Induced Null Alleles and Normal Alleles in Drosophila melanogester%黑腹果蝇杂合体中ADH杂二聚体的形成

    Institute of Scientific and Technical Information of China (English)

    童耕雷; 郑有丽; 徐晋麟; 李坤宝



  10. Lack of evidence for AT1R/B2R heterodimerization in COS-7, HEK293, and NIH3T3 cells: how common is the AT1R/B2R heterodimer?

    DEFF Research Database (Denmark)

    Hansen, Jakob L; Hansen, Jonas T; Speerschneider, Tobias


    dimerization using bioluminescence resonance energy transfer and regulated secretion/aggregation technology. However, although both the AT1Rs and B2Rs were functional in our systems and the systems were fine tuned to detect small changes in receptor function, we failed to detect any functional modulation...

  11. A heterodimer of a VHH (variable domains of camelid heavy chain-only) antibody that inhibits anthrax toxin cell binding linked to a VHH antibody that blocks oligomer formation is highly protective in an anthrax spore challenge model. (United States)

    Moayeri, Mahtab; Leysath, Clinton E; Tremblay, Jacqueline M; Vrentas, Catherine; Crown, Devorah; Leppla, Stephen H; Shoemaker, Charles B


    Anthrax disease is caused by a toxin consisting of protective antigen (PA), lethal factor, and edema factor. Antibodies against PA have been shown to be protective against the disease. Variable domains of camelid heavy chain-only antibodies (VHHs) with affinity for PA were obtained from immunized alpacas and screened for anthrax neutralizing activity in macrophage toxicity assays. Two classes of neutralizing VHHs were identified recognizing distinct, non-overlapping epitopes. One class recognizes domain 4 of PA at a well characterized neutralizing site through which PA binds to its cellular receptor. A second neutralizing VHH (JKH-C7) recognizes a novel epitope. This antibody inhibits conversion of the PA oligomer from "pre-pore" to its SDS and heat-resistant "pore" conformation while not preventing cleavage of full-length 83-kDa PA (PA83) by cell surface proteases to its oligomer-competent 63-kDa form (PA63). The antibody prevents endocytosis of the cell surface-generated PA63 subunit but not preformed PA63 oligomers formed in solution. JKH-C7 and the receptor-blocking VHH class (JIK-B8) were expressed as a heterodimeric VHH-based neutralizing agent (VNA2-PA). This VNA displayed improved neutralizing potency in cell assays and protected mice from anthrax toxin challenge with much better efficacy than the separate component VHHs. The VNA protected virtually all mice when separately administered at a 1:1 ratio to toxin and protected mice against Bacillus anthracis spore infection. Thus, our studies show the potential of VNAs as anthrax therapeutics. Due to their simple and stable nature, VNAs should be amenable to genetic delivery or administration via respiratory routes.

  12. Nuevos receptores nucleares heterodiméricos: reguladores metabólicos con impacto en fisiopatología y su proyección terapéutica en dislipidemias y diabetes mellitus


    Cortés,Víctor; Quezada, Nicolás; Rigotti, Attilio; Maiz, Alberto


    The regulation of gene expression is crucial for the normal development and the homeostatic maintenance of body tissues. Thus, its malfunction may determine a variety of human disease conditions. A growing body of evidence has shown the overwhelming relevance of a new class of gene expression regulators: the heterodimeric nuclear receptors, a family of structurally related proteins involved in multiple biological functions. In response to activating ligands, these molecules bind to specific g...

  13. BMP2/7异源二聚体调控CIZ的表达与自身活性的关系%Relationship Between the Bioactivity of BMP2/7 Heterodimers and Its Regulation of CIZ Expression

    Institute of Scientific and Technical Information of China (English)

    潘秋辉; 杨松海; 董群伟; 孙奋勇


    BMP2/7异源二聚体的活性显著高于BMP2同源二聚体,但其机制并不清楚.采用哺乳动物细胞表达的BMP2/7异源二聚体处理成骨细胞MC3T3-E1,细胞化学染色发现BMP2/7的活性显著高于BMP2,报告载体p3GC2-LUX检测发现BMP2/7能够明显上调BMP/Smad通路的活性(P<0.05).但在成骨细胞中过表达CIZ(casinteracting zinc finger protein),能够显著抑制BMP2/7上调ALP与Osteocalcin的作用,并阻断BMP2/7对BMP/Smad通路的激活.同时发现BMP蛋白能够上调CIZ的表达,但BMP2/7的作用明显低于BMP2同源二聚体.可以认为BMP2/7能够诱导CIZ的表达,但由于作用较弱,所以对自身活性的反馈抑制作用也较弱,这可能是BMP2/7有着较强生物活性的关键所在.

  14. Experiment list: SRX190263 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement among these d...s. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement among

  15. Experiment list: SRX190321 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available sis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement amon... apoptosis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement

  16. Experiment list: SRX100568 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available osis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement amo...heterodimers compete for a common DNA target site (the E box) and rearrangement among these dimer forms prov

  17. Experiment list: SRX190354 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available s and heterodimers compete for a common DNA target site (the E box) and rearrangement among these dimer form... and heterodimers compete for a common DNA target site (the E box) and rearrangement among these dimer forms

  18. Experiment list: SRX190291 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement among the...tosis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement am

  19. Experiment list: SRX190360 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available sis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement amon... apoptosis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement

  20. Shallow-water Niphatidae (Haplosclerina, Haplosclerida, Demospongiae) from the São Sebastião Channel and its environs (tropical southwestern Atlantic),

    NARCIS (Netherlands)

    Pinheiro, U.S.; Berlinck, R.G.S.; Hajdu, E.


    Two niphatids are described here: Amphimedon viridis and Pachychalina alcaloidifera sp. nov. Amphimedon viridis is a common and conspicuous species in most of the tropical western Atlantic. Pachychalina alcaloidifera sp. nov. has this far been found only in the coasts of Rio de Janeiro and São Paulo

  1. Advances in CB1/OX1-GPCR heterodimer and their cross-talk interaction%大麻素受体1/食欲素受体1-G蛋白偶联受体异聚体及其交叉激活作用研究进展

    Institute of Scientific and Technical Information of China (English)

    朱飞; 王湘庆; 陈亚楠; 朗森阳; 张家堂


    大麻素受体1(cannabinoid receptor 1,CB1)和食欲素受体1(orexin receptor 1,OX1)同属G蛋白偶联受体(G-proteincoupled receptors,GPCRs),两者在体内分布广泛,均参与调节摄食、能量平衡、睡眠和觉醒、食物和药物的成瘾性等.两者作用位点接近,足以形成异聚体共同参与各项功能调节,多项研究表明,CB1/OX1存在交叉激活作用.本文对CB1和OX1的作用以及CB1/OX1异聚体的交叉激活作用进行综述,以期对其有更深入的认识,从而对CB 1/OX 1-GPCR新药研发起到一定指导作用.

  2. Acceleration of bone formation and implant osseointegration by BMP-2/7 heterodimers in vivo%重组BMP2/7诱导成骨和种植体骨整合的动物实验研究

    Institute of Scientific and Technical Information of China (English)

    王靖虓; 谷志远; 赵娟; 郑园娜; 刘铁; 毛英杰; 张欣; 高丽霞


    目的:探讨重组BMP2/7异二聚体在诱导成骨和骨整合中的作用.方法:10只广西巴马小型猪颅骨上,用空心钻造成直径8 mm、深4 mm的7个骨缺损.在缺损中心植入直径2.8 mm、长10mm的经喷砂处理纯钛种植体,缺损内随机填塞BMP2/7胶原海绵、BMP2胶原海绵、胶原海绵,分为BMP2/7、BMP2、胶原海绵对照组.于术后14天和21天分别处死5只动物、取材,行硬组织切片和显微CT检查.结果:术后14天BMP2/7组BV(Bone Volume)均值为45.4215mm3、BV/TV(TissueVolume)为0.2872,BMP2组BV均值为29.0673mm3、BV/TV为0.1991,胶原海绵组BV均值为17.1824mm3、BV/TV为0.1167.术后21天BMP2/7组BV均值为67.3024mm3、BV/TV为0.4610,BMP2组BV均值为52.1323mm3、BV/TV为0.3373,胶原海绵组BV均值为34.0631mm3、BV/TV为0.2309.经统计学检查,三组之间存在明显差异(P<0.05).结论:BMP2/7比BMP2有更好的诱导成骨和种植体骨整合作用.

  3. Effect of different extraction procedures on antimicrobial activity of marine bivalves: A comparison

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, S.; Chatterji, A.; Das, P.

    Anti-bacterial activity was evaluated in different crude extracts of five commercially important edible marine bivalves, namely Meretrix casta (Chemnitz), Polymesoda (Geloina) P. erosa (Solander), Perna viridis (Linnaeus), Crassostrea gryphoides...

  4. Three New Rhizopulvinaria Species (Homoptera: Coccoidea: Coccidae) for Scale Insect Fauna of Turkey


    Kaydan, Mehmet Bora


    Three Rhizopulvinaria species, Rhizopulvinaria pyrethri Borchsenius, Rhizopulvinaria turkestanica (Archangelskaya), and Rhizopulvinaria viridis Borchsenius, were identified on wild flora in eastern Anatolia in 1997. All of them are new records for the Turkish scale insect fauna.

  5. Ten new species of Cicindelidae

    NARCIS (Netherlands)

    Horn, Walther


    Differt ab Od. simulatore m. statura majore; labro longiore, in medio (ab basi ad apicem) viridi-tincto, dente mediana distincta; fronte latiore, oculis magis prominentibus, vittis discoidalibus deficientibus; thorace breviore latiore, postice rainus angustato; elytris longioribus, magis parallelis,

  6. Protein (Cyanobacteria): 281806 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available se with PAS/PAC and GAF sensors Oscillatoria nigro-viridis PCC 7112 MIEESKSIKEKFGVLDSVPVGACLLQDDFVVLFWNTCLEE...YP_007117793.1 1117:4890 1150:2464 1158:318 482564:246 179408:246 diguanylate cycla

  7. Protein (Cyanobacteria): 281805 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available se with PAS/PAC and GAF sensors Oscillatoria nigro-viridis PCC 7112 MYLILPDLYANMTYQIDERLNTSPCGFLSFADDGTIVMVN...YP_007118829.1 1117:4890 1150:2464 1158:318 482564:246 179408:246 diguanylate cycla

  8. Protein (Cyanobacteria): 281754 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available se with PAS/PAC and GAF sensors Oscillatoria nigro-viridis PCC 7112 MLYNNEILPTLTVESSPRSMNILLYKLLSLRRIEYIAVDR...YP_007115817.1 1117:4890 1150:2464 1158:318 482564:246 179408:246 diguanylate cycla

  9. Disruption of microbial biofilms by an extracellular protein isolated from epibiotic tropical marine strain of Bacillus licheniformis

    Digital Repository Service at National Institute of Oceanography (India)

    Dusane, D.H.; Damare, S.R.; Nancharaiah, Y.V.; Ramaiah, N.; Venugopalan, V.P.; Kumar, A.R.; Zinjarde, S.S.

    from the surface of green mussel, Perna viridis showed antimicrobial activity against pathogenic Candida albicans BH, Pseudomonas aeruginosa PAO1 and biofouling Bacillus pumilus TiO1 cultures. The antimicrobial activity was lost after treatment...

  10. Genetic analysis of the marine mussel Perna viridis (Bivalvia: Mytilidae) based on mitochondrial COI sequence and its phylogenetic relationship with other congeneric species%基于COI序列的翡翠股贻贝Perna viridis线粒体遗传特性分析及其近缘种间的系统关系探讨

    Institute of Scientific and Technical Information of China (English)

    位正鹏; 孔晓瑜; 吴相云; 喻子牛


    应用通用引物COIL 1490和COtH 2198对翡翠股贻贝Perna viridis的性腺和体细胞线粒体DNA进行PCR扩增,获得661bp长度的COI基因片段,经过比对性腺与体细胞的COI片段,发现雄性性腺与体细胞COI基因均为一个单倍型,即体内只有一种线粒体DNA类型,没有发现双单性遗传现象,雌、雄性腺的COI基因片段变异率很低(0.31%).应用 PAUP构建NJ树、MP树以及贝叶斯法构建了贝叶斯树,对股贻吡属3种间的系统关系进行了分析,结果表明,翡翠股贻贝P.viridis、p.canaliculus和P.perna之间的分化与分歧年代的估算是相吻合的.


    Institute of Scientific and Technical Information of China (English)

    杨小玲; 杨瑞强; 江桂斌


    用贻贝和牡蛎作为生物指示物研究渤海近岸水体中丁基锡的污染现状.结果表明,丁基锡检出率达100%.总丁基锡浓度在23.4ng Sn·g-1至 162.4ng Sn·g-1 范围内,平均浓度为64.8ng Sn·g-1.在丁基锡化合物中三丁基锡为主要的污染物,表明我国继续使用含有三丁基锡的船舶防污涂料.贻贝和牡蛎对丁基锡化合物具有相似的富集能力.海产品中丁基锡的污染对人们的健康存在潜在的影响.

  12. Canopy-forming seaweeds in urchin-dominated systems in eastern Canada: structuring forces or simple prey for keystone grazers?

    Directory of Open Access Journals (Sweden)

    Caitlin Blain

    Full Text Available Models of benthic community dynamics for the extensively studied, shallow rocky ecosystems in eastern Canada emphasize kelp-urchin interactions. These models may bias the perception of factors and processes that structure communities, for they largely overlook the possible contribution of other seaweeds to ecosystem resilience. We examined the persistence of the annual, acidic (H2SO4, brown seaweed Desmarestia viridis in urchin barrens at two sites in Newfoundland (Canada throughout an entire growth season (February to October. We also compared changes in epifaunal assemblages in D. viridis and other conspicuous canopy-forming seaweeds, the non-acidic conspecific Desmarestia aculeata and kelp Agarum clathratum. We show that D. viridis can form large canopies within the 2-to-8 m depth range that represent a transient community state termed "Desmarestia bed". The annual resurgence of Desmarestia beds and continuous occurrence of D. aculeata and A. clathratum, create biological structure for major recruitment pulses in invertebrate and fish assemblages (e.g. from quasi-absent gastropods to >150,000 recruits kg(-1 D. viridis. Many of these pulses phase with temperature-driven mass release of acid to the environment and die-off in D. viridis. We demonstrate experimentally that the chemical makeup of D. viridis and A. clathratum helps retard urchin grazing compared to D. aculeata and the highly consumed kelp Alaria esculenta. In light of our findings and related studies, we propose fundamental changes to the study of community shifts in shallow, rocky ecosystems in eastern Canada. In particular, we advocate the need to regard certain canopy-forming seaweeds as structuring forces interfering with top-down processes, rather than simple prey for keystone grazers. We also propose a novel, empirical model of ecological interactions for D. viridis. Overall, our study underscores the importance of studying organisms together with cross-scale environmental

  13. Trypanosomiasis-induced Th17-like immune responses in carp

    NARCIS (Netherlands)

    Ribeiro, C.M.S.; Pontes, M.J.S.L.; Bird, S.; Chadzinska, M.K.; Scheer, M.H.; Verburg-van Kemenade, B.M.L.; Savelkoul, H.F.J.; Wiegertjes, G.F.


    Background - In mammalian vertebrates, the cytokine interleukin (IL)-12 consists of a heterodimer between p35 and p40 subunits whereas interleukin-23 is formed by a heterodimer between p19 and p40 subunits. During an immune response, the balance between IL-12 and IL-23 can depend on the nature of th

  14. Gclust Server: 88646 [Gclust Server

    Lifescience Database Archive (English)

    Full Text Available 88646 SCE_YOL090W=MSH2 Cluster Sequences - 964 Protein that forms heterodimers, with Msh3p and Msh6... Protein that forms heterodimers, with Msh3p and Msh6p, that bind to DNA mismatches to initiate the mismatch

  15. Experiment list: SRX190184 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available nd heterodimers compete for a common DNA target site (the E box) and rearrangement among these dimer forms p...d heterodimers compete for a common DNA target site (the E box) and rearrangement among these dimer forms pr

  16. Experiment list: SRX190319 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available iation and apoptosis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement...fferentiation and apoptosis. The homodimers and heterodimers compete for a common DNA target site (the E box) and rearrangement

  17. Effect of unialgal diets on the composition of fatty acids and sterols in juvenile ark shell Tegillarca granosa Linnaeus. (United States)

    Xu, Jilin; Zhou, Haibo; Yan, Xiaojun; Zhou, Chengxu; Zhu, Peng; Ma, Bin


    This study has investigated the effects of six different unialgal diets ( Chaetoceros calcitrans , Platymonas helgolandica , Chlorella sp., Isochrysis galbana , Nannochloropsis oculata , and Pavlova viridis ) on the composition of fatty acids and sterols in juvenile ark shell Tegillarca granosa Linnaeus. The best feeding effects on the growth of shellfish were found in C. calcitrans, followed by I. galbana and P. viridis, whereas Chlorella sp. and N. oculata exhibited relatively poor effects. The fatty acid and sterol compositions in the six microalgae and the juvenile ark shell after feeding were analyzed, and 39 fatty acids and 18 sterols were identified. Although the results demonstrate a close correlation between the sterol compositions in algal species and juvenile ark shell, a similar correlation was not observed between fatty acids. In the juvenile ark shell fed microalgae, the ratio of total saturated fatty acids (SFA) rapidly decreases, whereas the proportion of total polyunsaturated fatty acids (PUFAs) increases considerably. The abundances of AA, EPA, and DHA increase most significantly in shellfish with better growth (fed C. calcitrans, I. galbana, and P. viridis). The number of sterol species is reduced, but the total sterol content in groups fed corresponding microalgae increases, and abundant plant sterols, instead of cholesterol, are accumulated in juvenile ark shell fed appropriate microalgae I. galbana and P. viridis. Therefore, to be more conducive to human health, I. galbana and P. viridis, of the six experimental microalgae, are recommended for artificial ark shell culture.

  18. Micropropagation of Lavandula spp. (United States)

    Gonçalves, Sandra; Romano, Anabela


    Lavandula species are some of the most popular ornamental and medicinal plants with great economic values. These species are vegetative propagated by stem cuttings. However, the poor rooting ability and vulnerability of plantlets to contamination are major limiting factors for propagation. In vitro culture methods are suitable to overcome these limitations. This chapter describes protocols for in vitro propagation of Lavandula viridis L'Hér and Lavandula vera DC. Nodal shoot proliferation of L. viridis and plant regeneration from leaf-derived callus of L. vera by an "open culture system" are highlighted.

  19. Collective plasmon modes in a compositionally asymmetric nanoparticle dimer

    Directory of Open Access Journals (Sweden)

    Fuyi Chen


    Full Text Available The plasmon coupling phenomenon of heterodimers composed of silver, gold and copper nanoparticles of 60 nm in size and spherical in shape were studied theoretically within the scattered field formulation framework. In-phase dipole coupled σ-modes were observed for the Ag-Au and Ag-Cu heterodimers, and an antiphase dipole coupled π-mode was observed for the Ag-Au heterodimer. These observations agree well with the plasmon hybridization theory. However, quadrupole coupled modes dominate the high energy wavelength range from 357-443 nm in the scattering cross section of the D=60 nm Ag-Au and Ag-Cu heterodimer. We demonstrate for the first time that collective plasmon modes in a compositionally asymmetric nanoparticle dimer have to be predicted from the dipole-dipole approximation of plasmon hybridization theory together with the interband transition effect of the constitutive metals and the retardation effect of the nanoparticle size.

  20. Ag nanoprisms with Ag₂S attachment.

    KAUST Repository

    Xiong, Shenglin


    Triangular Ag nanoprisms are a type of most-studied noble-metal nanostructures over the past decade owing to their special structural architecture and outstanding optical and catalytic properties for a wide range of applications. Nevertheless, in contrast to active research for the synthesis of phase-pure Ag nanoprisms, no asymmetric heterodimers containing Ag prisms have been developed so far, probably due to lack of suitable synthetic methods. Herein, we devise a simple ion-exchange method to synthesize Ag2S/Ag heterodimers at room temperature, through which Ag nanoprisms with controllable size and thickness can be fabricated. Formation chemistry and optical properties of the heterodimers have been investigated. These semiconductor/metal heterodimers have exhibited remarkable bactericidal activity to E. coli cells under visible light illumination.

  1. Uptake and loss of mercury, cadmium and lead in marine organisms

    Digital Repository Service at National Institute of Oceanography (India)

    Kureishy, T.W.; DeSilva, C.

    Experiments were conducted on Tilapia mosambica, Perna viridis and Villorita cyprinoides on the uptake and loss of Hg, Cd and Pb in various tissues of these organisms. Hg was found to be highly toxic to the clams as compared to the fish and mussels...


    Directory of Open Access Journals (Sweden)

    Jeannette Jeannette


    Full Text Available In the S. E. Asiatic genus Spatholobus 28 species are recognized, 6 of which are never described before: S. albus^ S. auricomus, S. auritus, S. hirsutus, S. multiflorus and S. viridis. One variety (S. ferrugineus var. acutus is also newly described. A key and full descriptions with plates and maps to illustrate the distribution are given.

  3. The stable microbiome of inter and sub-tidal anemone species under increasing pCO2 (United States)

    Muller, Erinn M.; Fine, Maoz; Ritchie, Kim B.


    Increasing levels of pCO2 within the oceans will select for resistant organisms such as anemones, which may thrive under ocean acidification conditions. However, increasing pCO2 may alter the bacterial community of marine organisms, significantly affecting the health status of the host. A pH gradient associated with a natural volcanic vent system within Levante Bay, Vulcano Island, Italy, was used to test the effects of ocean acidification on the bacterial community of two anemone species in situ, Anemonia viridis and Actinia equina using 16 S rDNA pyrosequencing. Results showed the bacterial community of the two anemone species differed significantly from each other primarily because of differences in the Gammaproteobacteria and Epsilonproteobacteria abundances. The bacterial communities did not differ within species among sites with decreasing pH except for A. viridis at the vent site (pH = 6.05). In addition to low pH, the vent site contains trace metals and sulfide that may have influenced the bacteria community of A. viridis. The stability of the bacterial community from pH 8.1 to pH 7.4, coupled with previous experiments showing the lack of, or beneficial changes within anemones living under low pH conditions indicates that A. viridis and A. equina will be winners under future ocean acidification scenarios.

  4. Water relations in millipedes from some alpine habitat types (Central Alps, Tyrol) (Diplopoda)

    NARCIS (Netherlands)

    Meyer, Erwin; Eisenbeis, Gerhard


    Five species of millipedes, living cither in a mixed oak wood (alt. 670 m) (Enantiulus nanus, Mastigona mutabilis) or in an Alnus viridis community (alt. 2000 m) ( Leptoiulus saltuvagus, Haasea fonticulorum and Ochogona caroli) and the nival species Trimerophorella nivicomes are compared in respect

  5. De Apterygotenfauna van het eiland Urk

    NARCIS (Netherlands)

    Buitendijk, A.M.


    Op een tweetal excursies (van 11—13 Juli en van 26—28 September) werden op Urk negen soorten van Apterygogenea gevonden, n. 1.: Hypogastrura viatica (Tullb.). Friesea mirabilis (Tullb.). Onychiurus armatus (Tullb.). Proisotoma schötti (D. T.). Isotoma (Vertagopus) cinerea (Nic.). Isotoma viridis Bou

  6. Dicty_cDB: Contig-U08145-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available . 50 1e-04 AF021822_1( AF021822 |pid:none) Scaptodrosophila lebanonensis supe... ...emonia viridis copper/zinc super... 49 6e-04 AF021824_1( AF021824 |pid:none) Hirtodrosophila pictiventris su

  7. The status of Vespertilio borbonicus E. Geoffroy, 1803 (Chiroptera: Vespertilionidae)

    NARCIS (Netherlands)

    Hill, J.E.


    The taxonomic history of Scotophilus borbonicus (E. Geoffroy, 1803) from Réunion Island is reviewed and summarised, with the designation of a lectotype. The insular form that it represents is considered conspecific with the small Scotophilus viridis (Peters, 1852) of southern Africa. As a result, Sc

  8. Descriptions de Coléoptères nouveaux de la famille des Eumolpides

    NARCIS (Netherlands)

    Lefèvre, M.Ed.


    Breviter ovata, convexa, subtus brunneo-picea, capite prothoraceque nigris, viridi-reflexo-œnescentibus, nitidis, labro, palpis, antennis pedibusque fulvis, elytris fulvis (sutura tota lata nigro-picea, vage reflexo-œnea), singulo maculis duabus (altera intra impressionem basalem,, postice magis min

  9. On a new species of Lanistes

    NARCIS (Netherlands)

    Schepman, M.M.


    Testa sinistrorsa, anguste umbilicata, conico-globosa, aut flavido- aut viridi-olivacea, semper fasciis spiralibus purpureis angustis in anfr. ultimo picta; spira scalaris, magis minusve conica; apex obtusus. Anfr. 5½, superne vel acute angulati vel carinati, supra plani, carina interdum linea spira

  10. Genetic diversity and population structure of collard landraces and their relationship to other Brassica oleracea crops (United States)

    Landraces have the potential to provide a reservoir of genetic diversity for crop improvement to combat the genetic erosion of the food supply. A landrace collection of the vitamin-rich specialty crop collard (Brassica oleracea var. viridis) was genetically characterized to assess its potential for ...

  11. Genetic diversity and population structure of collard landraces (United States)

    A common vegetable grown in the southeastern U.S. is the leafy green cole crop known as collard (Brassica oleracea L. covar. Acephala var. viridis). Predominantly a fall and winter crop, collard is one of the few vegetables found in the garden during cool seasons in the Southeast. Historically, th...

  12. Genetic diversity and population structure of collard landraces collected in the Southeast (United States)

    Collard (Brassica oleracea L. covar. Acephala var. viridis) is a common vegetable grown throughout the southeastern United States. This non-heading, leafy-green cole crop is mostly grown during cooler seasons (e.g., fall through spring), but in some areas it is effectively grown year round. In th...

  13. Corallimorpharia collected during the CANCAP expeditions (1976-1986) in the south-eastern part of the North Atlantic*

    NARCIS (Netherlands)

    Hartog, den J.C.; Ocaña, O.; Brito, A.


    Species of Corallimorpharia collected during the CANCAP expeditions in the south-eastern part of the North Atlantic are described and discussed, altogether five species belonging to three genera of Corallimorphidae: the shallow water forms Corynactis viridis Allman, 1846, Pseudocorynactis caribbeoru

  14. Cyperaceae surinamenses novae vel criticae

    NARCIS (Netherlands)

    Uittien, H.


    Cyperus ruderalis Uitt. nov. spec. Annuus, viridis, culmis caespitosis, complanatis, raro trigonis, striatis, apicem versus modice setulosis, 6—10 cm longis, 1—1,5 mm latis, basi 0—2-foliatis. Foliis culmo multo brevioribus vel subaequilongis, 1,5—2,5 mm latis. Umbella simplex vel interdum mediocrit

  15. A new species of Corybas (Orchidaceae) from Papua New Guinea

    NARCIS (Netherlands)

    Kores, Paul


    Herba parva erecta, 1—3(—7) cm alta. Tuber globosum, 4—6 mm diam., albidum aut dilute brunneum, subtiliter villosum. Rhizomata atque pars subterranea albida. sparse villosa. Pars supraterranea caulis dilute viridis, glabra, ad basim per unicam vaginam tubularem inclusa. Vagina 8—12 mm longa, uninerv

  16. Adapt, move or die - how will tropical coral reef fishes cope with ocean warming?

    DEFF Research Database (Denmark)

    Habary, Adam; Johansen, Jacob L; Nay, Tiffany J.


    poleward, away from ocean warming hotspots where temperatures 2-3 °C above long-term annual means can compromise critical physiological processes. We examined the capacity of a model species - a thermally sensitive coral reef fish, Chromis viridis (Pomacentridae) - to use preference behaviour to regulate...

  17. Conditional Reduction of Predation Risk Associated with a Facultative Symbiont in an Insect.

    Directory of Open Access Journals (Sweden)

    Sarah Polin

    Full Text Available Symbionts are widespread among eukaryotes and their impacts on the ecology and evolution of their hosts are meaningful. Most insects harbour obligate and facultative symbiotic bacteria that can influence their phenotype. In the pea aphid Acyrthosiphon pisum, an astounding symbiotic-mediated phenotype has been recently observed: when infected with the symbiotic bacteria Rickettsiella viridis, young red aphid larvae become greener at adulthood and even darker green when co-infected with Rickettsiella viridis and Hamiltonella defensa. As body colour affects the susceptibility towards natural enemies in aphids, the influence of the colour change due to these facultative symbionts on the host survival in presence of predators was tested. Our results suggested that the Rickettsiella viridis infection may impact positively host survival by reducing predation risk. Due to results from uninfected aphids (i.e., more green ones attacked, the main assumption is that this symbiotic infection would deter the predatory ladybird feeding by reducing the profitability of their hosts rather than decreasing host detection through body colour change. Aphids co-infected with Rickettsiella viridis and Hamiltonella defensa were, however, more exposed to predation suggesting an ecological cost associated with multiple infections. The underlying mechanisms and ecological consequences of these symbiotic effects are discussed.

  18. First Record of a Neozygites species (Zygomycetes:Entomophthorales) Infecting Springtails (Insecta:Collembola)

    DEFF Research Database (Denmark)

    Steenberg, T; Eilenberg, J; Bresciani, J.


    A fungal pathogen from the Entomophthorales (Zygomycetes) was discovered in populations of the lucerne flea Sminthurus viridis (Collembola) collected from grassland and leguminous crops in Denmark during July to October. The morphology of the fungus was studied in springtails, collected live, which...

  19. A Review of Marine Growth Protection System (MGPS) Options for the Royal Australian Navy (United States)


    DSTO-TR-2631 2.5.2 Protection or remediation  Mexel® 432 is a “ molecular level” filming agent of proprietary formulation which is marketed as...Salinity and temperature tolerances of the green and brown mussels, Perna viridis and Perna perna (Bivalvia: Mytilidae). Revista de Biologia Tropical

  20. Ultrastructural examination of the pycnidia and conidia of the genus Opegrapha (Arthoniales, Ascomycota

    Directory of Open Access Journals (Sweden)

    Anetta Wieczorek


    Full Text Available The paper presents a summary of examinations on the variation of pycnidia and conidia of the following Opegrapha species occurring in Poland: O. atra, O. calcarea, O. dolomitica, O. gyrocarpa, O. niveoatra, O. rupestris, O. varia, O. vermicellifera, O. viridis and O. vulgata.

  1. Identification of estrogen receptor dimer selective ligands reveals growth-inhibitory effects on cells that co-express ERα and ERβ.

    Directory of Open Access Journals (Sweden)

    Emily Powell

    Full Text Available Estrogens play essential roles in the progression of mammary and prostatic diseases. The transcriptional effects of estrogens are transduced by two estrogen receptors, ERα and ERβ, which elicit opposing roles in regulating proliferation: ERα is proliferative while ERβ is anti-proliferative. Exogenous expression of ERβ in ERα-positive cancer cell lines inhibits cell proliferation in response to estrogen and reduces xenografted tumor growth in vivo, suggesting that ERβ might oppose ERα's proliferative effects via formation of ERα/β heterodimers. Despite biochemical and cellular evidence of ERα/β heterodimer formation in cells co-expressing both receptors, the biological roles of the ERα/β heterodimer remain to be elucidated. Here we report the identification of two phytoestrogens that selectively activate ERα/β heterodimers at specific concentrations using a cell-based, two-step high throughput small molecule screen for ER transcriptional activity and ER dimer selectivity. Using ERα/β heterodimer-selective ligands at defined concentrations, we demonstrate that ERα/β heterodimers are growth inhibitory in breast and prostate cells which co-express the two ER isoforms. Furthermore, using Automated Quantitative Analysis (AQUA to examine nuclear expression of ERα and ERβ in human breast tissue microarrays, we demonstrate that ERα and ERβ are co-expressed in the same cells in breast tumors. The co-expression of ERα and ERβ in the same cells supports the possibility of ERα/β heterodimer formation at physio- and pathological conditions, further suggesting that targeting ERα/β heterodimers might be a novel therapeutic approach to the treatment of cancers which co-express ERα and ERβ.

  2. Association of amino acids embedded in helium droplets detected by mass spectrometry (United States)

    Lalanne, Matthieu R.; Achazi, Georg; Reichwald, Sebastian; Lindinger, Albrecht


    Amino acids were embedded in helium droplets. The electron impact ionization allows for detecting positively charged glycine, valine, histidine, tryptophan and their principal fragments. Monomers and polymers with up to four amino acids are reported. Heterodimers of tryptophan and valine or histidine are observed as well as heterodimers of included fragments. The ability of these associations of molecules to form complexes with water is examined.

  3. The integrins


    Takada, Yoshikazu; Ye, Xiaojing; Simon, Scott


    The integrins are a superfamily of cell adhesion receptors that bind to extracellular matrix ligands, cell-surface ligands, and soluble ligands. They are transmembrane αβ heterodimers and at least 18 α and eight β subunits are known in humans, generating 24 heterodimers. Members of this family have been found in mammals, chicken and zebrafish, as well as lower eukaryotes, including sponges, the nematode Caenorhabditis elegans (two α and one β subunits, generating two integrins) and the fruitf...

  4. Vitamin-D's molekylære effekt på cellecyklus og onkogenese

    DEFF Research Database (Denmark)

    Schmidt, J; Wittenhagen, P; Hørder, M


    The active metabolite of vitamin D, 1,25 (OH)2D3, exerts its cell cycle regulating effects via binding to VDR (Vitamin D Receptor). This complex forms a heterodimer with RXR (Retinoic X Receptor). The VDR-RXR heterodimer binds to promoter regions of cell cycle regulating genes through a vitamin D...... epidemiological investigations give strong support for the benefits of vitamin D in preventing colon cancer and prostate cancer. Udgivelsesdato: 1998-Jul-20...

  5. Molecular Imaging of Ovarian Carcinoma Angiogenesis (United States)


    proteins with large extracellular segments that pair to create heterodimers with distinct adhesive capabilities (29). In mammals , 18 a and 8 h subunits...segments that pair to create heterodimers (αβ) with distinct adhesive capabilities. In mammals , 18 α and 8 β subunits assemble into 24 different...vascular endothelial growth factor (VEGF), fibroblast growth factor ( FGF ), epidermal growth factor (EGF), etc.] and antiangiogenic molecules

  6. Efeito do bentazon e bentazon + dichlorprop na cultura do arroz irrigado e sobre as plantas daninhas Effect of bentazon and bentazon + dichlorprop on irrigated rice and weeds

    Directory of Open Access Journals (Sweden)

    C.A.L. dos Santos


    Full Text Available Foi instalado um experimento de campo, em solo barrento, com a finalidade de se verificar o efeito do bentazon e da mistura de bentazon + dichlorprop sobre o desenvolvimento do arroz em cultura irrigada e sobre o controle das plantas daninhas. Os tratamentos utilizados foram os seguintes: bentazon á 0,75-1,00 e1,50 kg/ha; bentazon + dichlorprop a 0,80 + 1,00 e 1,00 + 1,40 kg/ha; propanil a 4,20 kg/ha (tratamento padrão; testemunha capinada e testemunha sem capina. Todas as pulverizações foram realizadas em pósemergência. As plantas daninhas encontradas no experimento foram: capituva - Echinochloa colonum (L Link, tiririca amarela - Cyperus esculentus L., beldroega - Portulaca oleracea L. e carurú comum - Amaranthus viridis L. Bentazon a 1,00 e 1,50 kg/ha e bentazon + dichlorprop a 1,00 + 1,40 kg/ha foram eficientes no controle de P. oleracea, A. viridis e C. esculentus; já a dose menor de bentazon apresentou bons resultados contra P. oleracea e A. viridis, enquanto que a dose menor de bentazon + dichlorprop controlou apenas P. oleracea. Propanil, de uma maneira geral, proporcionou eficiente ação sobre as plantas daninhas. Nas condições em que foi realizado o experimento nenhum dos herbicidas, nas suas respectivas doses, apresentou fitotoxicidade para as plantas de arroz da variedade IAC-435 ou prejudicou a produção da cultura.Bentazon at 0.75 - 1.00 and 1.50 kg/ha a.i ., bentazon + dichlorprop at 0.80 + 1.00 and 1.00 + 1.40 kg and propanil at 4.20 kg were applied in post-emergence on irrigated rice, against the following weeds: Echinochloa colonum (L. Link, Cy-perus esc-ulentus L., Portulaca oleracea L. and Amaranthus viridis L. Bentazon at 1.00 - 1.50 kg and bentazon + dichlorprop at 1.00 + 1.40 kg gave good control of P. oleracea, A. viridis and C. esculentus; bentazon at 0.75 kg controlled P. oleracea and A. viridis; bentazon + dichlorprop at 0.80 + 1.00 kg only showed effeciency for P. oleracea; propanil, in general, gave good

  7. The deaf and the dumb: the biology of ErbB-2 and ErbB-3. (United States)

    Citri, Ami; Skaria, Kochupurakkal Bose; Yarden, Yosef


    ErbB-2 (also called HER2/neu) and ErbB-3 are closely related to the epidermal growth factor receptor (EGFR/ErbB-1), but unlike EGFR, ErbB-2 is a ligandless receptor, whereas ErbB-3 lacks tyrosine kinase activity. Hence, both ErbB-2 and ErbB-3 are active only in the context of ErbB heterodimers, and ErbB-2. ErbB-3 heterodimers, which are driven by neuregulin ligands, are the most prevalent and potent complexes. These stringently controlled heterodimers are repeatedly employed throughout embryonic development and dictate the establishment of several cell lineages through mesenchyme-epithelial inductive processes and the interactions of neurons with muscle, glia, and Schwann cells. Likewise, the potent combination of signaling pathways engaged by the heterodimers drives an aggressive phenotype of tumors of secretory epithelia, including breast and lung cancers. This review highlights recent structural insights into the mechanism of ligand-induced heterodimer formation, and concentrates on signaling pathways employed by ErbB-2 and ErbB-3 in normal and in malignant cells.

  8. Accumulation patterns of lipophilic organic contaminants in surface sediments and in economic important mussel and fish species from Jakarta Bay, Indonesia. (United States)

    Dwiyitno; Dsikowitzky, Larissa; Nordhaus, Inga; Andarwulan, Nuri; Irianto, Hari Eko; Lioe, Hanifah Nuryani; Ariyani, Farida; Kleinertz, Sonja; Schwarzbauer, Jan


    Non-target screening analyses were conducted in order to identify a wide range of organic contaminants in sediment and animal tissue samples from Jakarta Bay. High concentrations of di-iso-propylnaphthalenes (DIPNs), linear alkylbenzenes (LABs) and polycyclic aromatic hydrocarbons (PAHs) were detected in all samples, whereas phenylmethoxynaphthalene (PMN), DDT and DDT metabolites (DDX) were detected at lower concentrations. In order to evaluate the uptake and accumulation by economic important mussel (Perna viridis) and fish species, contaminant patterns of DIPNs, LABs and PAHs in different compartments were compared. Different patterns of these contaminant groups were found in sediment and animal tissue samples, suggesting compound-specific accumulation and metabolism processes. Significantly higher concentrations of these three contaminant groups in mussel tissue as compared to fish tissue from Jakarta Bay were found. Because P. viridis is an important aquaculture species in Asia, this result is relevant for food safety.

  9. Burial of Zostera marina seeds in sediment inhabited by three polychaetes: laboratory and field studies

    DEFF Research Database (Denmark)

    Delefosse, Matthieu; Kristensen, Erik


    The large number of seeds produced by eelgrass, Zostera marina, provides this plant with a potential to disperse widely and colonise newareas. After dispersal, seedsmust be buried into sediment for assuring long-term survival, successful germination and safe seedling development. Seedsmay be buried......–3200 ind m −2), Arenicola marina (20–80 ind m−2), and the invasive Marenzelleria viridis (400–1600 ind m −2). The obtained results were subsequently compared with burial rates of seed mimics in experimental field plots (1m2) dominated by the respective polychaetes. High recovery of seeds in the laboratory...... (97–100%) suggested that none of these polychaetes species feed on eelgrass seeds. N. diversicolor transported seeds rapidly (marina and M. viridis buried seeds by depositing their faeces on top of the sediment...

  10. Amphinomidae y Euphrosinidae (Annelida: Polychaeta de la costa nororiental de Venezuela Amphinomidae and Euphrosinidae (Annelida: Polychaeta from northeastern coast of Venezuela

    Directory of Open Access Journals (Sweden)

    Ildefonso Liñero-Arana


    Full Text Available Se identificaron ejemplares pertenecientes a ocho especies de Amphinomidae y una de Euphosinidae recolectados en diferentes lugares de la costa oriental de Venezuela: Amphinome rostrata, Chloeia viridis, Chloenopsis atlantica, Eurythoë complanata, Hermodice carunculata, Linopherus cana-riensis, L. paucibranchiata, Notopygos crinita (Amphinomidae y Euphrosine triloba (Euphrosinidae. Excepto para Eurythoë, Hermodice y Notopygos, los demás géneros y/o especies constituyen nuevos registros para la costa de Venezuela.Specimens belonging to eight species of Amphinomidae and one of Euphosinidae collected in different localities of the East coast of Venezuela were identified: Amphinome rostrata, Chloeia viridis, Chloenopsis atlantica, Eurythoë complanata, Hermodice carunculata, Linopherus canariensis, L. pauci-branchiata, Notopygos crinita (Amphinomidae and Euphrosine triloba (Euphrosinidae. Except for Eurythoë, Hermodice and Notopygos, the remain genera or species constitute new records from Venezuelan coast.

  11. Nutritional and toxic factors in selected wild edible plants. (United States)

    Guil, J L; Rodríguez-García, I; Torija, E


    Nutritional (ascorbic acid, dehydroascorbic acid and carotenes); antinutritional and toxic components (oxalic acid, nitrate and erucic acid) were determined in sixteen popular species of wild edible plants which are collected for human consumption in southeast Spain. Ascorbic + dehydroascorbic acids contents were very high in several species, especially in Chenopodium album L. (155 mg/100 g). Carotenoid content ranged from 4.2 mg/100 g (Stellaria media Villars) to 15.4 mg/100 g (Amaranthus viridis L.). A range of values was found for oxalic acid from absence to 1100 mg/100 g of plant material. Nitrate contents ranged from 47 mg/100 g (Salicornia europaea L.) to 597 mg/100 g (Amaranthus viridis L.). Low amounts of erucic acid were found in the Cruciferae family (Sisymbrium irio L. 1.73%; Cardaria draba L. 1.23%) and Plantago major L. 3.45%.

  12. Spatial pattern and ecological process in the coffee agroforestry system. (United States)

    Perfecto, Ivette; Vandermeer, John


    The coffee agroforestry system provides an ideal platform for the study of spatial ecology. The uniform pattern of the coffee plants and shade trees allows for the study of pattern generation through intrinsic biological forces rather than extrinsic habitat patchiness. Detailed studies, focusing on a key mutualism between an ant (Azteca instabilis) and a scale insect (Coccus viridis), conducted in a 45-ha plot in a coffee agroforestry system have provided insights into (1) the quantitative evaluation of spatial pattern of the scale insect Coccus viridis on coffee bushes, (2) the mechanisms for the generation of patterns through the combination of local satellite ant nest formation and regional control from natural enemies, and (3) the consequences of the spatial pattern for the stability of predator-prey (host-parasitoid) systems, for a key coccinelid beetle preying on the scale insects and a phorid fly parasitoid parasitizing the ant.

  13. Physical Non-Contact Communication between Microscopic Aquatic Species: Novel Experimental Evidences for an Interspecies Information Exchange

    Directory of Open Access Journals (Sweden)

    Daniel Fels


    Full Text Available Previous experiments on physical non-contact communication within same species gave rise to test for this type of communication also across the species border, which was the aim of the present study. It was found that autotrophic unicellular organisms (Euglena viridis, separated by cuvettes, affected the proliferation rate of heterotrophic unicellular organisms (Paramecium caudatum. Further, the heterotrophic unicellular organism affected also the proliferation rate of a multicellular heterotrophic organism (Rotatoria sp. and vice versa. In the case when populations (of Euglena viridis and Paramecium caudatum were shielded against electromagnetic fields in the optical spectrum from each other, no effects were measured. The results may support the notion that the organisation of ecosystems relies also on the exchange of electromagnetic fields from their constituting biosystems.

  14. Robust biological nitrogen fixation in a model grass-bacterial association. (United States)

    Pankievicz, Vânia C S; do Amaral, Fernanda P; Santos, Karina F D N; Agtuca, Beverly; Xu, Youwen; Schueller, Michael J; Arisi, Ana Carolina M; Steffens, Maria B R; de Souza, Emanuel M; Pedrosa, Fábio O; Stacey, Gary; Ferrieri, Richard A


    Nitrogen-fixing rhizobacteria can promote plant growth; however, it is controversial whether biological nitrogen fixation (BNF) from associative interaction contributes to growth promotion. The roots of Setaria viridis, a model C4 grass, were effectively colonized by bacterial inoculants resulting in a significant enhancement of growth. Nitrogen-13 tracer studies provided direct evidence for tracer uptake by the host plant and incorporation into protein. Indeed, plants showed robust growth under nitrogen-limiting conditions when inoculated with an ammonium-excreting strain of Azospirillum brasilense. (11)C-labeling experiments showed that patterns in central carbon metabolism and resource allocation exhibited by nitrogen-starved plants were largely reversed by bacterial inoculation, such that they resembled plants grown under nitrogen-sufficient conditions. Adoption of S. viridis as a model should promote research into the mechanisms of associative nitrogen fixation with the ultimate goal of greater adoption of BNF for sustainable crop production.

  15. Understanding trophic relationships among Caribbean sea urchins


    Rodriguez Barreras, Ruber; Cuevas, Elvira; Cabanillas-Terán, Nancy; Branoff, Benjamin


    The species Echinometra lucunter, Echinometra viridis, Lytechinus variegatus, Tripneustes ventricosus, and Diadema antillarum are the most common sea urchins of littoral habitats in the Caribbean. T. ventricosus and L. variegatus are associated with seagrass beds, while the other three species usually inhabit hardground substrates. Food preferences of these species are well documented and they are commonly accepted as being primarily herbivorous-omnivorous; nevertheless, few of them have prev...

  16. Local distribution and thermal ecology of two intertidal fishes. (United States)

    Pulgar, Jose M; Bozinovic, Francisco; Ojeda, F Patricio


    Geographic variability in the physiological attributes of widely distributed species can be a result of phenotypic plasticity or can reflect evolutionary responses to a particular habitat. In the field, we assessed thermal variability in low and high intertidal pools and the distribution of resident fish species Scartichthys viridis and transitory Girella laevifrons along this vertical intertidal gradient at three localities along the Chilean coast: Antofagasta (the northernmost and warmest habitat), Carrizal Bajo (central coast) and Las Cruces (the southernmost and coldest habitat). In the laboratory, we evaluated the thermal sensitivity of fish captured from each locality. The response to temperature was estimated as the frequency of opercular movements and as thermal selectivity in a gradient; the former being a indirect indicator of energy costs in a particular environment and the latter revealing differential occupation of habitat. Seawater temperature in intertidal pools was greatest at Antofagasta, and within each site was greatest in high intertidal pools. The two intertidal fish species showed opposite patterns of local distribution, with S. viridis primarily inhabiting the lower sectors of the intertidal zone, and G. laevifrons occupying the higher sectors of the intertidal zone. This pattern was consistent for all three localities. Locality was found to be a very important factor determining the frequency of opercular movement and thermal selectivity of both S. viridis and G. laevifrons. Our results suggest that S. viridis and G. laevifrons respond according to: (1) the thermal history of the habitat from which they came, and (2) the immediate physical conditions of their habitat. These results suggest local adaptation rather than plasticity in thermoregulatory and energetic mechanisms.

  17. Inhibitory Effects of Several Essential Oils towards Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B


    S.F. Mazhar; F. Aliakbari; Karami-Osboo, R.; D. Morshedi; P. Shariati; D. Farajzadeh


    Plant essential oils are natural products extracted from plants and because of their antimicrobial properties can be used as natural additives in foods. They are also useful for decontamination of food-borne pathogens and can be a safe additive in foods. The antimicrobial activities of essential oils belonging to Saturiea hortensis, Thymus vulgaris, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. (spearmint) were investigated at different concentrations (0.1, 0.3...

  18. New Discoveries of Plants From Hebei Province%河北植物新增补属、种与入侵物种新分布

    Institute of Scientific and Technical Information of China (English)

    曲红; 路端正; 王百田


    报道了《河北植物志》与《河北高等植物名录》未记录的植物1属3种1变种.其中拔毒散(Sida szechuensis Matsuda)、偃狗尾草[Setaria viridis (L.) Beauv. var. depressa(Honda) Kitag.]在河北省首次记录.

  19. The Role of Mixing in the Mechanisms of Water Bloom by Microcystis spp.


    SIHOTANG, CLEMENS; Okino, Tokio


    Studies on the role of water mixing in the mechanisms of water bloom by Microcystis spp., which were composed from the three species, M. aeruginosa, M. viridis and M. wesenbergii, were conducted during the summer of 1983. Microcystis spp. are a species of blue-green algae that appears regularly in the summer in Lake Suwa, Japan. Centrifugation was used in order to separate Microcystis spp. from other phytoplankton. Thus, the floating part of the centrifugal tube was occupied by Microcystis sp...

  20. Long-Term Changes in Beach Fauna at Duck, North Carolina. (United States)


    and Gulf of Mexico coasts, while not diverse, has been remarkably successful in coping with unstable substrate caused by high kinetic wave energy...lecolepides vir-idis + + Laeonereio culveri + + Lyeippides grayi ++ Po Zydora ligni+ Oligochaeta + + Mollusca Ran gia cuneata + + Macomaz sp. + Phyea sp...Tropics, Vol. 22, 1974, pp. 51-66. DEXTER, D.M., "The Sandy-beach Fauna of Mexico ," Southwest, Nature, Vol. 20, 1976, pp. 479-485. DIAZ, H., "The Mole Crab

  1. Area Strip Mine Reclamation Using Dredged Material: A Field Demonstration. (United States)


    capillare BARNYARD GRASS Echnochloa crusgalli GREEN FOXTAIL Setaria viridis GIANT FOXTAIL Setaria faberi CYPERACEAE RED-FOOTED SEDGE Cyperus erythrorhizos...marigold (Figures 15, 16, and 18 in the main text). The open mudflat areas are inhabited almost solely by rud rooted sedge , sprangletop, oak-leaved...goosefoot and red rooted sedge . Other species abundant in these areas include sprangletop and barnyard grass 7. The total 42 species surveyed as

  2. The use of intertidal molluscs in the monitoring of heavy metals and organotin compounds in the west coast of Peninsular Malaysia


    Ismail, Ahmad


    Over 60% of human activities in the west coast of Peninsular Malaysia are concentrated in the coastal areas. High human activities in the coastal areas may cause hazardous chemical pollution. In this report, intertidal molluscs were used to assess heavy metals pollution in the coastal areas of the west coast of Peninsular Malaysia. Intertidal gastropods such as Thais, Cherithedia and Nerita, and bivalves such as Anadara, Isognomon alatus and Perna viridis have been studied and analysed for th...

  3. Indian marine bivalves: Potential source of antiviral drugs

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Bichurina, M.A.; Sovetova, M.; Boikov, Y.A.

    in large quantities by traditional methods and sold live in the market for human consumption. The economically important sp e cies of marine bivalves are green mussel ( Perna viridis ), e s tuarine oyster ( Crassostrea madrasensis ), giant oyster... in developing an effecti ve drug has been the unique characteristics of antigenic variation of virus resulting in the emergence of new variant virus strains 14 . There are a number of antiviral drugs introduced in the market such as tricyclic sy m- metric...

  4. LPS-induced NO inhibition and antioxidant activities of ethanol extracts and their solvent partitioned fractions from four brown seaweeds (United States)

    Cho, Myoung Lae; Lee, Dong-Jin; Lee, Hyi-Seung; Lee, Yeon-Ju; You, Sang Guan


    The nitric oxide inhibitory (NOI) and antioxidant (ABTS and DPPH radical scavenging effects with reducing power) activities of the ethanol (EtOH) extracts and solvent partitioned fractions from Scytosiphon lomentaria, Chorda filum, Agarum cribrosum, and Desmarestia viridis were investigated, and the correlation between biological activity and total phenolic (TP) and phlorotannin (TPT) content was determined by PCA analysis. The yield of EtOH extracts from four brown seaweeds ranged from 2.6 to 6.6% with the highest yield from D. viridis, and the predominant compounds in their solvent partitioned fractions had medium and/or less polarity. The TP and TPT content of the EtOH extracts were in the ranges of 25.0-44.1 mg GAE/g sample and 0.2-4.6 mg PG/g sample, respectively, which were mostly included in the organic solvent partitioned fractions. Strong NOI activity was observed in the EtOH extracts and their solvent partitioned fractions from D. viridis and C. filum. In addition, the EtOH extract and its solvent partitioned fractions of D. viridis exhibited little cytotoxicity to Raw 264.7 cells. The most potent ABTS and DPPH radical scavenging capacity was shown in the EtOH extracts and their solvent partitioned fractions from S. lomentaria and C. filum, and both also exhibited strong reducing ability. In the PCA analysis the content of TPT had a good correlation with DPPH ( r = 0.62), ABTS ( r = 0.69) and reducing power ( r = 0.65), however, an unfair correlation was observed between the contents of TP and TPT and NOI, suggesting that the phlorotannins might be responsible for the DPPH and ABTS radical scavenging activities.

  5. Detecting age-structured effects in growth performance of coral reef fish juveniles


    Mellin, Camille; Galzin, R.; Ponton, Dominique; Vigliola, Laurent


    The growth performance of coral reef fish juveniles collected in different habitats is often used as a proxy for habitat quality for juveniles. However, back-calculated growth trajectories of juveniles may be age-structured, for instance, because of potential differences in initial offspring size and/or quality or size-selective mortality. A novel approach is proposed to isolate growth performance of coral reef fish juveniles from potential age-based factors. Juveniles of Chromis viridis (Pom...

  6. Synthesis and anti-HIV evaluation of hybrid-type prodrugs conjugating HIV integrase inhibitors with d4t by self-cleavable spacers containing an amino acid residue. (United States)

    Fossey, Christine; Huynh, Ngoc-Trinh; Vu, Anh-Hoang; Vidu, Anamaria; Zarafu, Irina; Laduree, Daniel; Schmidt, Sylvie; Laumond, Geraldine; Aubertin, Anne-Marie


    In an attempt to combine the anti-HIV inhibitory capacity of reverse transcriptase (RT) inhibitors (NRTIs) and integrase (IN) inhibitors (INIs), several heterodimer analogues of the previously reported [d4T]-PABC-[INI] and [d4T]-OABC-[INI] prototypes have been prepared. In these novel series, we wished to extend our results to conjugates which incorporated an enzymatically labile aminoacid unit (L-alanine) connected to d4T through a self-immolative para- or ortho-aminobenzyl carbonate (PABC or OABC) spacer. Among the novel heterodimers, several derivatives show a potent anti-HIV-1 activity, which proved comparable to that of the [L-708,906]-PABC-[d4T] Heterodimer A prototype. However, although the compounds proved inhibitory to HIV-1, they were less potent than the parent compounds from which they were derived.

  7. Crystal structure of Spot 14, a modulator of fatty acid synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Colbert, Christopher L.; Kim, Chai-Wan; Moon, Young-Ah; Henry, Lisa; Palnitkar, Maya; McKean, William B.; Fitzgerald, Kevin; Deisenhofer, Johann; Horton, Jay D.; Kwon, Hyock Joo (Alnylam Pharm.); (UTSMC)


    Spot 14 (S14) is a protein that is abundantly expressed in lipogenic tissues and is regulated in a manner similar to other enzymes involved in fatty acid synthesis. Deletion of S14 in mice decreased lipid synthesis in lactating mammary tissue, but the mechanism of S14's action is unknown. Here we present the crystal structure of S14 to 2.65 {angstrom} and biochemical data showing that S14 can form heterodimers with MIG12. MIG12 modulates fatty acid synthesis by inducing the polymerization and activity of acetyl-CoA carboxylase, the first committed enzymatic reaction in the fatty acid synthesis pathway. Coexpression of S14 and MIG12 leads to heterodimers and reduced acetyl-CoA carboxylase polymerization and activity. The structure of S14 suggests a mechanism whereby heterodimer formation with MIG12 attenuates the ability of MIG12 to activate ACC.

  8. Solution Structures of PPARγ2/RXRα Complexes

    Directory of Open Access Journals (Sweden)

    Judit Osz


    Full Text Available PPARγ is a key regulator of glucose homeostasis and insulin sensitization. PPARγ must heterodimerize with its dimeric partner, the retinoid X receptor (RXR, to bind DNA and associated coactivators such as p160 family members or PGC-1α to regulate gene networks. To understand how coactivators are recognized by the functional heterodimer PPARγ/RXRα and to determine the topological organization of the complexes, we performed a structural study using small angle X-ray scattering of PPARγ/RXRα in complex with DNA from regulated gene and the TIF2 receptor interacting domain (RID. The solution structures reveal an asymmetry of the overall structure due to the crucial role of the DNA in positioning the heterodimer and indicate asymmetrical binding of TIF2 to the heterodimer.

  9. [Is it possible to "cancel" aging process of cell cultures under optimal conditions for cultivation?]. (United States)

    Bozhkov, A I; Kovaleva, M K; Menzianova, N G


    The characteristics of the cells epigenotypes Dunaliella viridis Teod. in the process of chronological and replicative aging were investigated. By 40th day of accumulative cultivation (which coincided with the stationary growth phase) DNA content in the cells of Dunaliella viridis increased 2 times, triacylglycerides 3 times, beta-carotene and carbonyl proteins 2 times, RNA content decreased in comparison with cells in exponential growth phase, i. e., the 40th day of growth of culture forms the age-related epigenotype. 4 received subcultures were being transplanted during 2 years in mid-logarithmic growth phase (subculture-10), early stationary phase of growth (subculture-20), in the mid-stationary growth phase (subculture-30), and late stationary growth phase (subculture-40). It is shown that epigenotype of subculture-10 remained unchanged over 2 years of cultivation, i. e., it does not manifest replicative aging. At the same time, the subculture-20, although long enough (at least 40 passages), maintained epigenotype characteristic of young cultures, and showed age-related changes. Pronounced age-dependent changes of epigenotype in the course of cultivation were identified for subculture-30, and subculture-40 was characterized by unstable epigenotype. Thus, cultivation conditions determine the intensity of replicative aging in Dunaliella viridis.

  10. Effects of ocean acidification on the metabolic rates of three species of bivalve from southern coast of China

    Institute of Scientific and Technical Information of China (English)

    LIU Wenguang; HE Maoxian


    Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH,a process known as “ocean acidification”.The pearl oyster Pinctada fucata,the noble scallop Chlamys nobilis,and the green-lipped mussel Perna viridis are species of economic and ecological importance along the southern coast of China.We evaluated the effects of seawater acidification on clearance,respiration,and excretion rates in these three species.The animals were reared in seawater at pH 8.1 (control),7.7,or 7.4.The clearance rate was highest at pH 7.7 for P.fucata and at pH 8.1 for C.nobilis and P.viridis.The pH had little effect on the respiration rate of P.fucata and P.viridis.In contrast,the respiration rate was significantly lower at pH 7.4 in C.nobilis.The excretion rate was significantly lower at pH 7.4 than pH 8.1 for all species.The results indicate that the reduction in seawater pH likely affected the metabolic process (food intake,oxygen consumption,and ammonia excretion) of these bivalves.Different species respond differently to seawater acidification.Further studies are needed to demonstrate the exact mechanisms for this effect and evaluate adaptability of these bivalves to future acidified oceans.

  11. In vitro evaluation of the ovistatic and ovicidal effect of the cosmopolitan filamentous fungi isolated from soil on Ascaris suum eggs. (United States)

    Blaszkowska, Joanna; Kurnatowski, Piotr; Wojcik, Anna; Goralska, Katarzyna; Szwabe, Katarzyna


    The ovicidal activity of seven fungal strains: Acremonium alabamense, Alternaria chlamydospora, Cladosporium herbarum, Fusarium solani, Paecilomyces variotii, Paecilomyces viridis and Penicillium verruculosum isolated from urban soil samples from Poland was determined in vitro. The fungal mycelium was co-cultured with Ascaris suum eggs on plates with 2% water-agar for 28 days. Eggs exposed and unexposed (control) to fungal mycelium were observed weekly by light microscopy and the percentage of malformed eggs were determined. The eggs were classified according to following parameters: type 1 - biochemical and physiological effect without morphological damage to the eggshell; type 2 - lytic effect with morphological alteration of the eggshell and embryo; type 3 - lytic effect with morphological alteration of eggshell and embryo with hyphal penetration and internal egg colonization. All examined species of fungi extended embryogenesis, but the retardation of embryonic development was varied and depended on the species. A. alabamense, A. chlamydospora and P. verruculosum exhibited very high inhibitory activity on A. suum egg development. The fungus-exposed eggs revealed morphological alternations in all stages of embryogenesis. Isolates of F. solani, P. variotii and P. viridis showed hyphal penetration and internal colonization of A. suum eggs (type 3 effect). No appressoria were produced and simple hyphal penetrations were most commonly observed. A. alabamense and P. verruculosum demonstrated morphological destruction, with eggshell destruction. The remaining fungi showed type 1 effect. The results demonstrated that examined strains of F. solani, P. variotii and P. viridis may be considered to be potential limiting factors of parasitic geohelminth populations.

  12. Grasses suppress shoot-borne roots to conserve water during drought. (United States)

    Sebastian, Jose; Yee, Muh-Ching; Goudinho Viana, Willian; Rellán-Álvarez, Rubén; Feldman, Max; Priest, Henry D; Trontin, Charlotte; Lee, Tak; Jiang, Hui; Baxter, Ivan; Mockler, Todd C; Hochholdinger, Frank; Brutnell, Thomas P; Dinneny, José R


    Many important crops are members of the Poaceae family, which develop root systems characterized by a high degree of root initiation from the belowground basal nodes of the shoot, termed the crown. Although this postembryonic shoot-borne root system represents the major conduit for water uptake, little is known about the effect of water availability on its development. Here we demonstrate that in the model C4 grass Setaria viridis, the crown locally senses water availability and suppresses postemergence crown root growth under a water deficit. This response was observed in field and growth room environments and in all grass species tested. Luminescence-based imaging of root systems grown in soil-like media revealed a shift in root growth from crown-derived to primary root-derived branches, suggesting that primary root-dominated architecture can be induced in S. viridis under certain stress conditions. Crown roots of Zea mays and Setaria italica, domesticated relatives of teosinte and S. viridis, respectively, show reduced sensitivity to water deficit, suggesting that this response might have been influenced by human selection. Enhanced water status of maize mutants lacking crown roots suggests that under a water deficit, stronger suppression of crown roots actually may benefit crop productivity.


    Kosmala, Sylwia; Karnkowska-Ishikawa, Anna; Milanowski, Rafał; Kwiatowski, Jan; Zakryś, Bożena


    Morphological and molecular studies, as well as original literature reexamination, necessitate establishment of five Euglena species with a single axial, stellate chloroplast [Euglena viridis (O. F. Müller) Ehrenberg 1830, Euglena pseudoviridis Chadefaud 1937, Euglena stellata Mainx 1926, Euglena pseudostellata sp. nov., and Euglena cantabrica Pringsheim 1956], three species with two chloroplasts (Euglena geniculata Dujardin ex Schmitz 1884, Euglena chadefaudii Bourrelly 1951, and Euglena pseudochadefaudii sp. nov.), and one species with three chloroplasts (Euglena tristella Chu 1946). The primary morphological features, allowing distinction of the considered species are the presence and the shape of mucocysts, as well as the number of chloroplasts. Spherical mucocysts occur in E. cantabrica and E. geniculata, while spindle-shaped mucocysts are present in E. stellata, E. pseudostellata, E. chadefaudii, E. pseudochadefaudii, and E. tristella. No mucocysts are observed in E. viridis and E. pseudoviridis. Two new species (E. pseudochadefaudii sp. nov. and E. pseudostellata sp. nov.) differ from the respective species, E. chadefaudii and E. stellata, only at the molecular level. Molecular signatures and characteristic sequences are designated for nine distinguished species. Emended diagnoses for all and delimitation of epitypes for seven species (except E. viridis and E. tristella) are proposed.

  14. Epigenetics of dominance for enzyme activity

    Indian Academy of Sciences (India)

    Kuldip S Trehan; Kulbir S Gill


    We have isolated and purified two parental homodimers and a unique heterodimer of acid phosphatase [coded by Acph-11.05() and Acph-10.95()] from isogenic homozygotes and heterozygotes of Drosophila malerkotliana. and produce qualitatively different allozymes and the two alleles are expressed equally within and across all three genotypes and and play an equal role in the epigenetics of dominance. Subunit interaction in the heterodimer over a wide range of H+ concentrations accounts for the epigenetics of dominance for enzyme activity.

  15. Residues of the UL25 Protein of Herpes Simplex Virus That Are Required for Its Stable Interaction with Capsids ▿


    Cockrell, Shelley K.; Huffman, Jamie B.; Toropova, Katerina; James F Conway; Homa, Fred L.


    The herpes simplex virus 1 (HSV-1) UL25 gene product is a minor capsid component that is required for encapsidation, but not cleavage, of replicated viral DNA. UL25 is located on the capsid surface in a proposed heterodimer with UL17, where five copies of the heterodimer are found at each of the capsid vertices. Previously, we demonstrated that amino acids 1 to 50 of UL25 are essential for its stable interaction with capsids. To further define the UL25 capsid binding domain, we generated reco...

  16. Calculation of the Electromagnetic Field Around a Microtubule

    Directory of Open Access Journals (Sweden)

    D. Havelka


    Full Text Available Microtubules are important structures in the cytoskeleton which organizes the cell. A single microtubule is composed of electrically polar structures, tubulin heterodimers, which have a strong electric dipole moment. Vibrations are expected to be generated in microtubules, thus tubulin heterodimers oscillate as electric dipoles. This gives rise to an electromagnetic field which is detected around the cells. We calculate here the electromagnetic field of microtubules if they are excited at 1 GHz. This paper includes work done for the bachelor thesis of the first author. 

  17. Moisture Absorption and Retention of Plysaccharides from Four Marine Shellfishes%4种海洋贝类多糖提取和保湿性研究

    Institute of Scientific and Technical Information of China (English)

    邓一清; 童银洪; 陈小丽; 梁飞龙; 杜晓东


    Polysaccharides were obtained from the whole viscera of marine shellfishes Pinctada martensii, Pteria penguin, Perna viridis and Crassostrea rivularis by hot water extraction. Moisture absorption of the polysaccharidc extractions from the four shellfishes were evaluated in contrast with traditional humectants such as glycerol, 1,3-butanediol, propanediol, PEG-400. At a relative humidity of 44%, the order of moisture absorption rate at 12 hours of the humectants was as follows: Pinctada martensii < Crassostrea rivularis< Pteria penguin < Perna viridis < PEG-400 < 1, 3-butanediol < glycerol < propanediol. At a relative humidity of 80%, the order of moisture absorption rate at 12 hours of the humectants listed as follows: Crassostrea rivularis < Pinctada martensii < Pteria penguin < 1,3-butanediol < Perna viridis < PEG-400 < glycerol Perna viridis > Pinctada martensii> Pteria penguin > glycerol > 1, 3-butanediol> propanediol > PEG-400. Moisture absorption rate of polysaccharide from Perna viridis was superior to the other shellfishes, and inferior to traditional humectants. Moisturizing retention rate of polysaccharide of Perna viridis was inferior to oyster, and superior to the others.%以马氏珠母贝(Pinctada martensii)、企鹅珍珠贝(Pteria penguin)、翡翠贻贝(Perna viridis)和近江牡蛎(oyster)的内脏团为原料提取、纯化多糖,与甘油、聚乙二醇400( PEG-400)、丙二醇和1,3-丁二醇四种常规保湿剂进行比较.结果表明,在相对湿度为44%时,前12h吸湿率顺序为:马氏珠母贝<近江牡蛎<企鹅珍珠贝<翡翠贻贝< PEG-400<1,3-丁二醇<甘油<丙二醇;在相对湿度为80%时,前12h吸湿率顺序为:近江牡蛎<马氏珠母贝<企鹅珍珠贝<1,3-丁二醇<翡翠贻贝< PEG-400<甘油<丙二醇.前12h的保湿率顺序为:近江牡蛎>翡翠贻贝>马氏珠母贝>企鹅珍珠贝>甘油>1,3-丁二醇>丙二醇> PEG-400.翡翠

  18. Characterization of lighted upflow anaerobic sludge blanket (LUASB) method under sulfate-rich conditions. (United States)

    Sawayama, S; Tsukahara, K; Yagishita, T; Hanada, S


    Growth of phototrophic bacteria was induced from granules in a lighted upflow anaerobic sludge blanket (LUASB) reactor supplied with an organic-acid-based medium containing 141.7 mg S.l(-1) of SO4(2-) under light conditions (100 microE.m(-2).s(-1)). We investigated the population dynamics of phototrophic bacteria in the LUASB reactor and the performance of the LUASB reactor for wastewater treatment and poly-beta-hydroxybutyrate (PHB) production under anaerobic light and sulfate-rich conditions. In vivo absorption spectra and a colony count suggested that populations of Rhodopseudomonas palustris and Blastochloris sulfoviridis in the LUASB reactor supplied with a medium containing 574.4 mg S.l(-1) of SO4(2-) under light conditions were lower than those supplied with a medium containing 1.0 or 141.7 mg S.l(-1) of SO4(2-) under parallel conditions. Removal efficiencies of ammonium and phosphate in the LUASB reactor supplied with the medium containing 141.7 mg S.l(-1) of SO4(2-) under light conditions were higher than those under parallel conditions but without illumination. The difference in the results of runs under light or dark conditions suggested that the ammonium and phosphate ion removal efficiencies were improved by increasing the amount of phototrophic bacterial biomass in the LUASB reactor under sulfate-rich conditions. The average PHB production rates of the bacterial cells recovered from the effluent of the LUASB reactor supplied with a medium containing 141.7, 283.5 or 574.4 mg S.l(-1) of SO4(2-) were 1.0-2.9 mg.l(-1)-reactor.d(-1) and the average PHB content based on the dry bacterial biomass was 1.4-3.6%.

  19. The cerebro-oculo-facio-skeletal syndrome point mutation F231L in the ERCC1 DNA repair protein causes dissociation of the ERCC1-XPF complex

    NARCIS (Netherlands)

    M. Faridounnia (Maryam); H. Wienk (Hans); L. Kovačič (Lidija); G.E. Folkers (Gert); N.G.J. Jaspers (Nicolaas); R. Kaptein (Robert); J.H.J. Hoeijmakers (Jan); R. Boelens (Rolf)


    textabstractThe ERCC1-XPF heterodimer, a structure-specific DNA endonuclease, is best known for its function in the nucleotide excision repair (NER) pathway. The ERCC1 point mutation F231L, located at the hydrophobic interaction interface of ERCC1 (excision repair cross-complementation group 1) and

  20. Dimerization drives EGFR endocytosis through two sets of compatible endocytic codes. (United States)

    Wang, Qian; Chen, Xinmei; Wang, Zhixiang


    We have shown previously that epidermal growth factor (EGF) receptor (EGFR) endocytosis is controlled by EGFR dimerization. However, it is not clear how the dimerization drives receptor internalization. We propose that EGFR endocytosis is driven by dimerization, bringing two sets of endocytic codes, one contained in each receptor monomer, in close proximity. Here, we tested this hypothesis by generating specific homo- or hetero-dimers of various receptors and their mutants. We show that ErbB2 and ErbB3 homodimers are endocytosis deficient owing to the lack of endocytic codes. Interestingly, EGFR-ErbB2 or EGFR-ErbB3 heterodimers are also endocytosis deficient. Moreover, the heterodimer of EGFR and the endocytosis-deficient mutant EGFRΔ1005-1017 is also impaired in endocytosis. These results indicate that two sets of endocytic codes are required for receptor endocytosis. We found that an EGFR-PDGFRβ heterodimer is endocytosis deficient, although both EGFR and PDGFRβ homodimers are endocytosis-competent, indicating that two compatible sets of endocytic codes are required. Finally, we found that to mediate the endocytosis of the receptor dimer, the two sets of compatible endocytic codes, one contained in each receptor molecule, have to be spatially coordinated.

  1. Molecular mechanisms of cooperative binding of transcription factors Runx1–CBFβ–Ets1 on the TCRα gene enhancer (United States)

    Kasahara, Kota; Shiina, Masaaki; Fukuda, Ikuo; Ogata, Kazuhiro; Nakamura, Haruki


    Ets1 is an essential transcription factor (TF) for several important physiological processes, including cell proliferation and differentiation. Its recognition of the enhancer region of the TCRα gene is enhanced by the cooperative binding of the Runx1–CBFβ heterodimer, with the cancelation of phosphorylation-dependent autoinhibition. The detailed mechanism of this interesting cooperativity between Ets1 and the Runx1–CBFβ heterodimer is still largely unclear. Here, we investigated the molecular mechanisms of this cooperativity, by using molecular dynamics simulations. Consequently, we detected high flexibility of the loop region between the HI2 and H1 helices of Ets1. Upon Runx1–CBFβ heterodimer binding, this loop transiently adopts various sub-stable conformations in its interactions with the DNA. In addition, a network analysis suggested an allosteric pathway in the molecular assembly and identified some key residues that coincide with previous experimental studies. Our simulations suggest that the cooperative binding of Ets1 and the Runx1–CBFβ heterodimer alters the DNA conformation and induces sub-stable conformations of the HI2–H1 loop of Ets1. This phenomenon increases the flexibility of the regulatory module, including the HI2 helix, and destabilizes the inhibitory form of this module. Thus, we hypothesize that this effect facilitates Ets1–DNA binding and prevents the phosphorylation-dependent DNA binding autoinhibition. PMID:28231333

  2. Low retinol levels differentially modulate bile salt-induced expression of human and mouse hepatic bile salt transporters

    NARCIS (Netherlands)

    M.O. Hoeke; J.R.M. Plass; J. Heegsma; M. Geuken; D. van Rijsbergen; J.F.W. Baller; F. Kuipers; H. Moshage; P.L.M. Jansen; K.N. Faber


    The farnesoid X receptor/retinoid X receptor-alpha (FXR/RXRalpha) complex regulates bile salt homeostasis, in part by modulating transcription of the bile salt export pump (BSEP/ABCB11) and small heterodimer partner (SHP/NR0B2). FXR is activated by bile salts, RXRalpha by the vitamin A derivative 9-

  3. Low Retinol Levels Differentially Modulate Bile Salt-Induced Expression of Human and Mouse Hepatic Bile Salt Transporters

    NARCIS (Netherlands)

    Hoeke, Martijn O.; Plass, Jacqueline R. M.; Heegsma, Janette; Geuken, Mariska; van Rijsbergen, Duncan; Baller, Julius F. W.; Kuipers, Folkert; Moshage, Han; Jansen, Peter L. M.; Faber, Klaas Nico


    The farnesoid X receptor/retinoid X receptor-alpha (FXR/RXR alpha) complex regulates bile salt homeostasis, in part by modulating transcription of the bile salt export pump (BSEP/ABCB11 I) and small heterodimer partner (SHP/NR0B2). FXR is activated by bile salts, RXR alpha by the vitamin A derivativ

  4. Alternation and tunable composition in hydrogen bonded supramolecular copolymers. (United States)

    Felder, Thorsten; de Greef, Tom F A; Nieuwenhuizen, Marko M L; Sijbesma, Rint P


    Sequence control in supramolecular copolymers is limited by the selectivity of the associating monomer end groups. Here we introduce the use of monomers with aminopyrimidinone and aminohydroxynaphthyridine quadruple hydrogen bonding end groups, which both homodimerize, but form even stronger heterodimers. These features allow the formation of supramolecular copolymers with a tunable composition and a preference for alternating sequences.

  5. Cell surface display of minor pilin adhesins in the form of a simple heterodimeric assembly in Corynebacterium diphtheriae. (United States)

    Chang, Chungyu; Mandlik, Anjali; Das, Asis; Ton-That, Hung


    Pilus assembly in Gram-positive bacteria occurs by a two-step mechanism, whereby pilins are polymerized and then covalently anchored to the cell wall. In Corynebacterium diphtheriae, the pilin-specific sortase SrtA catalyses polymerization of the SpaA-type pilus, consisting of the shaft pilin SpaA, tip pilin SpaC and minor pilin SpaB. Cell wall anchoring of the SpaA polymers is triggered when SrtA incorporates SpaB into the pilus base via lysine-mediated transpeptidation; anchoring to the cell wall peptidoglycan is subsequently catalysed by the housekeeping sortase SrtF. Here we show that SpaB and SpaC formed a heterodimer independent of SpaA polymerization. SrtA was absolutely required for the formation of the SpaBC heterodimer, while SrtF facilitated the optimal cell wall anchoring of this heterodimer. Alanine substitution of the SpaB lysine residue K139 or truncation of the SpaB cell wall-sorting signal (CWSS) abolished assembly of the SpaBC heterodimer, hence underscoring SpaB function in transpeptidation and cell wall linkage. Importantly, sortase specificity for the cell wall-anchoring step was found to be dependent on the LAFTG motif within the SpaB CWSS. Thus, C. diphtheriae employs a common sortase-catalysed mechanism involving lysine-mediated transpeptidation to generate both adhesive pilus and simple heterodimeric structures on the bacterial the cell wall.

  6. Structural basis for signaling by exclusive EDS1 heteromeric complexes with SAG101 or PAD4 in plant innate immunity. (United States)

    Wagner, Stephan; Stuttmann, Johannes; Rietz, Steffen; Guerois, Raphael; Brunstein, Elena; Bautor, Jaqueline; Niefind, Karsten; Parker, Jane E


    Biotrophic plant pathogens encounter a postinfection basal resistance layer controlled by the lipase-like protein enhanced disease susceptibility 1 (EDS1) and its sequence-related interaction partners, senescence-associated gene 101 (SAG101) and phytoalexin deficient 4 (PAD4). Maintainance of separate EDS1 family member clades through angiosperm evolution suggests distinct functional attributes. We report the Arabidopsis EDS1-SAG101 heterodimer crystal structure with juxtaposed N-terminal α/β hydrolase and C-terminal α-helical EP domains aligned via a large conserved interface. Mutational analysis of the EDS1-SAG101 heterodimer and a derived EDS1-PAD4 structural model shows that EDS1 signals within mutually exclusive heterocomplexes. Although there is evolutionary conservation of α/β hydrolase topology in all three proteins, a noncatalytic resistance mechanism is indicated. Instead, the respective N-terminal domains appear to facilitate binding of the essential EP domains to create novel interaction surfaces on the heterodimer. Transitions between distinct functional EDS1 heterodimers might explain the central importance and versatility of this regulatory node in plant immunity.

  7. Genome-wide ChIP-seq profiling of PPARγ/RXR target sites and gene program during adipogenesis

    DEFF Research Database (Denmark)

    Nielsen, Ronni; Pedersen, Thomas Åskov; Hagenbeek, Dik;

    Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors which bind to DNA as heterodimers with members of the retinoid X receptor family. PPARγ is an important regulator of adipocyte differentiation and function. In addition to driving the adipogenic process, PPARγ activates...

  8. Sequence Classification: 894094 [

    Lifescience Database Archive (English)

    Full Text Available n that forms heterodimers, with Msh3p and Msh6p, that bind to DNA mismatches to initiate the mismatch repair... process; contains a Walker ATP-binding motif required for repair activity; Msh2p-Msh6p binds to and hydrolyzes ATP; Msh2p || ...

  9. The newcomer in the integrin family: Integrin a9 in biology and cancer

    DEFF Research Database (Denmark)

    Høye, Anette Melissa; Couchman, John Robert; Wewer, Ulla M.


    Integrins are heterodimeric transmembrane receptors regulating cell-cell and cell-extracellular matrix interactions. Of the 24 integrin heterodimers identified in humans, a9ß1 integrin is one of the least studied. a9, together with a4, comprise a more recent evolutionary sub-family of integrins t...

  10. Domain Modeling: NP_001017388.1 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_001017388.1 chr4 Crystal structure of the TLR1-TLR2 heterodimer induced by of a tri-acylated lipopeptide p2z7xa_ chr4/NP_001017388.1/NP_001017388.1_holo_27-528.pdb blast 189N,190T,

  11. Domain Modeling: NP_001017404.1 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_001017404.1 chr1 Crystal structure of the TLR1-TLR2 heterodimer induced by of a tri-acylated lipopeptide p2z82a_ chr1/NP_001017404.1/NP_001017404.1_holo_2-421.pdb psi-blast 92W,115

  12. Identification of a novel antagonist of the ErbB1 receptor capable of inhibiting migration of human glioblastoma cells

    DEFF Research Database (Denmark)

    Staberg, Mikkel; Riemer, Christian; Xu, Ruodan


    BACKGROUND: Receptors of the ErbB family are involved in the development of various cancers, and the inhibition of these receptors represents an attractive therapeutic concept. Upon ligand binding, ErbB receptors become activated as homo- or heterodimers, leading to the activation of downstream...

  13. A bHLH-Based Feedback Loop Restricts Vascular Cell Proliferation in Plants

    NARCIS (Netherlands)

    Vera-Sirera, Francisco; Rybel, de B.P.M.; Urbez, Cristina; Kouklas, Evangelos; Pesquera, Marta; Alvarez-Mahecha, Juan Camilo; Minguet, Eugenio; Tuominen, Hanneke; Carbonell, Juan; Borst, J.W.; Weijers, D.; Blazquez, Miguel


    Control of tissue dimensions in multicellular organisms requires the precise quantitative regulation of mitotic activity. In plants, where cells are immobile,
    tissue size is achieved through control of both cell division orientation and mitotic rate. The bHLH transcription factor heterodimer for

  14. PatA and PatB form a functional heterodimeric ABC multidrug efflux transporter responsible for the resistance of Streptococcus pneumoniae to fluoroquinolones. (United States)

    Boncoeur, Emilie; Durmort, Claire; Bernay, Benoît; Ebel, Christine; Di Guilmi, Anne Marie; Croizé, Jacques; Vernet, Thierry; Jault, Jean-Michel


    All bacterial multidrug ABC transporters have been shown to work as either homodimers or heterodimers. Two possibly linked genes, patA and patB from Streptococcus pneumococcus, that encode half-ABC transporters have been shown previously to be involved in fluoroquinolone resistance. We showed that the ΔpatA, ΔpatB, or ΔpatA/ΔpatB mutant strains were more sensitive to unstructurally related compounds, i.e., ethidium bromide or fluoroquinolones, than the wild-type R6 strain. Inside-out vesicles prepared from Escherichia coli expressing PatA and/or PatB transported Hoechst 33342, a classical substrate of multidrug transporters, only when both PatA and PatB were coexpressed. This transport was inhibited either by orthovanadate or by reserpine, and mutation of the conserved Walker A lysine residue of either PatA or PatB fully abrogated Hoechst 33342 transport. PatA, PatB, and the PatA/PatB heterodimer were purified from detergent-solubilized E. coli membrane preparations. Protein dimers were identified in all cases, albeit in different proportions. In contrast to the PatA/PatB heterodimers, homodimers of PatA or PatB failed to show a vanadate-sensitive ATPase activity. Thus, PatA and PatB need to interact together to make a functional drug efflux transporter, and they work only as heterodimers.

  15. Role of Jumonji c-domain containing protein 6 (JMJD6) in infectivity of foot-and-mouth disease virus (United States)

    Foot-and-mouth disease virus (FMDV) can utilize as many as three distinct groups of receptor molecules to attach and enter a susceptible host cell. Four integrin heterodimers (alphavBeta1, alphavBeta3, alphavBeta6, and alphavBeta8) can function as the primary receptor for FMDV field strains. FMDV ...

  16. Identification of the subunit of cAMP receptor protein (CRP) that functionally interacts with CytR in CRP-CytR-mediated transcriptional repression

    DEFF Research Database (Denmark)

    Meibom, K L; Kallipolitis, B H; Ebright, R H


    At promoters of the Escherichia coli CytR regulon, the cAMP receptor protein (CRP) interacts with the repressor CytR to form transcriptionally inactive CRP-CytR-promoter or (CRP)(2)-CytR-promoter complexes. Here, using "oriented heterodimer" analysis, we show that only one subunit of the CRP dimer...

  17. Domain Modeling: NP_690007.1 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_690007.1 chr19 Crystal structure of a high affinity heterodimer of HIF2 alpha an...d ARNT C-terminal PAS domains p3f1pa_ chr19/NP_690007.1/NP_690007.1_apo_234-344.pdb blast 0 ...

  18. Domain Modeling: NP_001093587.1 [SAHG[Archive

    Lifescience Database Archive (English)


  19. Domain Modeling: NP_005797.1 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_005797.1 chr21 Crystal Structure of the basic-helix-loop-helix domains of the he...terodimer E47/NeuroD1 bound to DNA p2ql2d_ chr21/NP_005797.1/NP_005797.1_holo_110-166.pdb blast 113I,114N,11

  20. Domain Modeling: NP_150253.2 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_150253.2 chr15 Structure of the MID1 tandem B-boxes reveals an interaction remin...iscent of intermolecular RING heterodimers p2juna_ chr15/NP_150253.2/NP_150253.2_holo_124-225.pdb psi-blast

  1. 棉纤维发育初始基因的表达谱研究及其与拟南芥IAA16同源的GhIAA16基因的分离%Expressional Profiling of Genes Related to Cotton Fiber Initiation and Isolation of GhIAA16 Homologus to Arabidopsis IAA16

    Institute of Scientific and Technical Information of China (English)

    Jin-feng SUO; Xiao-e LIANG; Yong-biao XUE


    @@ The Aux/IAA genes are rapidly and specifically induced by the plant hormone auxin and encode short-lived nuclear proteins that are capable of forming homo- and hetero-dimer. Molecular,biochemical, and genetic data suggest that they play a central role in auxin signaling and plant development.

  2. Genome-Wide Profiling of Liver X Receptor, Retinoid X Receptor, and Peroxisome Proliferator-Activated Receptor α in Mouse Liver Reveals Extensive Sharing of Binding Sites

    DEFF Research Database (Denmark)

    Boergesen, Michael; Pedersen, Thomas Åskov; Gross, Barbara;


    The liver X receptors (LXRs) are nuclear receptors that form permissive heterodimers with retinoid X receptor (RXR) and are important regulators of lipid metabolism in the liver. We have recently shown that RXR agonist-induced hypertriglyceridemia and hepatic steatosis in mice are dependent on LXRs...

  3. Construction of covalently coupled, concatameric dimers of 7TM receptors

    DEFF Research Database (Denmark)

    Terpager, Marie; Scholl, D Jason; Kubale, Valentina;


    -Ala repeats flanked by flexible spacers and positively charged residues to ensure correct inside-out orientation plus an extracellular HA-tag to construct covalently coupled dimers of 7TM receptors. Such 15 TM concatameric homo- and heterodimers of the beta(2)-adrenergic and the NK(1) receptors, which...

  4. Upregulation of the transcription factor TFEB in t(6;11)(p21;q13)-positive renal cell carcinomas due to promoter substitution

    NARCIS (Netherlands)

    Kuiper, RP; Schepens, M; Thijssen, J; van Asseldonk, M; van den Berg, E; Bridge, J; Schuuring, E; Schoenmakers, EFPM; van Kessel, AG


    The MITF/TFE subfamily of basic helix-loop-helix leucine-zipper (bHLH-LZ) transcription factors consists of four closely related members, TFE3, TFEB, TFEC and MITF, which can form both homo- and heterodimers. Previously, we demonstrated that in t(X;1)(p11;q21)-positive renal cell carcinomas (RCCs),

  5. Monozygotic twins with a de novo 0.32 Mb 16q24.3 deletion, including TUBB3 presenting with developmental delay and mild facial dysmorphism but without overt brain malformation

    DEFF Research Database (Denmark)

    Grønborg, Sabine; Kjaergaard, Susanne; Hove, Hanne;


    Nervous system development is highly dependent on the function of microtubules, which are assembled from tubulin heterodimers containing several α- and β-tubulin isotypes encoded by separate genes. A spectrum of neurological disorders with malformations of the central nervous system has recently ...

  6. Domain Modeling: NP_004307.2 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_004307.2 chr12 Crystal Structure of the basic-helix-loop-helix domains of the he...terodimer E47/NeuroD1 bound to DNA p2ql2d_ chr12/NP_004307.2/NP_004307.2_holo_119-175.pdb psi-blast 120V,122

  7. Solution structure of the dimerization domain of the eukaryotic stalk P1/P2 complex reveals the structural organization of eukaryotic stalk complex. (United States)

    Lee, Ka-Ming; Yu, Conny Wing-Heng; Chiu, Teddy Yu-Hin; Sze, Kong-Hung; Shaw, Pang-Chui; Wong, Kam-Bo


    The lateral ribosomal stalk is responsible for the kingdom-specific binding of translation factors and activation of GTP hydrolysis during protein synthesis. The eukaryotic stalk is composed of three acidic ribosomal proteins P0, P1 and P2. P0 binds two copies of P1/P2 hetero-dimers to form a pentameric P-complex. The structure of the eukaryotic stalk is currently not known. To provide a better understanding on the structural organization of eukaryotic stalk, we have determined the solution structure of the N-terminal dimerization domain (NTD) of P1/P2 hetero-dimer. Helix-1, -2 and -4 from each of the NTD-P1 and NTD-P2 form the dimeric interface that buries 2200 A(2) of solvent accessible surface area. In contrast to the symmetric P2 homo-dimer, P1/P2 hetero-dimer is asymmetric. Three conserved hydrophobic residues on the surface of NTD-P1 are replaced by charged residues in NTD-P2. Moreover, NTD-P1 has an extra turn in helix-1, which forms extensive intermolecular interactions with helix-1 and -4 of NTD-P2. Truncation of this extra turn of P1 abolished the formation of P1/P2 hetero-dimer. Systematic truncation studies suggest that P0 contains two spine-helices that each binds one copy of P1/P2 hetero-dimer. Modeling studies suggest that a large hydrophobic cavity, which can accommodate the loop between the spine-helices of P0, can be found on NTD-P1 but not on NTD-P2 when the helix-4 adopts an 'open' conformation. Based on the asymmetric properties of NTD-P1/NTD-P2, a structural model of the eukaryotic P-complex with P2/P1:P1/P2 topology is proposed.

  8. Addition of positively charged tripeptide to N-terminus of the Fos basic region leucine zipper domain: implications on DNA bending, affinity, and specificity. (United States)

    Mahmoudi, T; Sarkar, B


    GKH-Fos(139-211)/Jun(248-334) (GKH: glycine-lysine-histidine) is a modified Fos/Jun heterodimer designed to contain a metal binding motif in the form of a GKH tripeptide at the amino terminus of Fos bZIP domain dimerized with the Jun basic region leucine zipper (bZIP) domain. We examined the effect of the addition of positively charged GKH motif to the N-terminus of Fos(139-211) on the DNA binding characteristics of the Fos(139-211)/Jun(248-334) heterodimer. Binding studies indicate that while the nonspecific DNA binding affinity of the GKH modified heterodimer increases 4-fold, it specifically binds the activating protein-1 (AP-1) site 6-fold less tightly than the control unmodified counterpart. Furthermore, helical phasing analysis indicates that GKH-Fos(139-211)/Jun(248-334) and control Fos(139-211)/Jun(248-334) both bend the DNA at the AP-1 site toward the minor groove. However, due to the presence of the positively charged GKH motif on Fos, the degree of the induced bend by GKH- Fos(139-211)/Jun(248-334) is greater than that induced by the unmodified Fos/Jun heterodimer. Our results suggest that the unfavorable energetic cost of the increased DNA bending by GKH-Fos(139-211)/Jun(248-334) results in a decrease in both specificity and affinity of binding of the heterodimer to the AP-1 site. These findings may have important implications in protein design as well in our understanding of DNA bending and factors responsible for the functional specificity of different members of the bZIP family of transcription factors.

  9. Influence of benthic macrofauna community shifts on ecosystem functioning in shallow estuaries

    Directory of Open Access Journals (Sweden)

    Erik eKristensen


    Full Text Available We identify how ecosystem functioning in shallow estuaries is affected by shifts in benthic fauna communities. We use the shallow estuary, Odense Fjord, Denmark, as a case study to test our hypotheses that (1 shifts in benthic fauna composition and species functional traits affect biogeochemical cycling with cascading effects on ecological functioning, which may (2 modulate pelagic primary productivity with feedbacks to the benthic system. Odense Fjord is suitable because it experienced dramatic shifts in benthic fauna community structure from 1998 to 2008. We focused on infaunal species with emphasis on three dominating burrow-dwelling polychaetes: the native Nereis (Hediste diversicolor and Arenicola marina, and the invasive Marenzelleria viridis. The impact of functional traits in the form of particle reworking and ventilation on biogeochemical cycles, i.e. sediment metabolism and nutrient dynamics, was determined from literature data. Historical records of summer nutrient levels in the water column of the inner Odense Fjord show elevated concentrations of NH4+ and NO3- (DIN during the years 2004-2006, exactly when the N. diversicolor population declined and A. marina and M. viridis populations expanded dramatically. In support of our first hypothesis, we show that excess NH4+ delivery from the benthic system during the A. marina and M. viridis expansion period enriched the overlying water in DIN and stimulated phytoplankton concentration. The altered benthic-pelagic coupling and stimulated pelagic production may, in support of our second hypothesis, have feedback to the benthic system by changing the deposition of organic material. We therefore advice to identify the exact functional traits of the species involved in a community shift before studying its impact on ecosystem functioning. We also suggest studying benthic community shifts in shallow environments to obtain knowledge about the drivers and controls before exploring deep

  10. Molecular identification key based on PCR/RFLP for three polychaete sibling species of the genus Marenzelleria, and the species' current distribution in the Baltic Sea (United States)

    Blank, M.; Laine, A. O.; Jürss, K.; Bastrop, R.


    Studies of Marenzelleria species were often hampered by identification uncertainties when using morphological characters only. A newly developed PCR/RFLP protocol allows a more efficient discrimination of the three species Marenzelleria viridis, Marenzelleria neglecta and Marenzelleria arctia currently known for the Baltic Sea. The protocol is based on PCR amplification of two mitochondrial DNA gene segments (16S, COI) followed by digestion with restriction enzymes. As it is faster and cheaper than PCR/sequencing protocols used so far, the protocol is recommended for large-scale analyses. The markers allow an undoubted determination of species irrespective of life stage or condition of the worms in the samples. The protocol was validated on about 950 specimens sampled at more than 30 sites of the Baltic and the North Sea, and on specimens from populations of the North American east coast. Besides this test we used mitochondrial DNA sequences (16S, COI, Cytb) and starch gel electrophoresis to further investigate the distribution of the three Marenzelleria species in the Baltic Sea. The results show that M. viridis (formerly genetic type I or M. cf. wireni) occurred in the Öresund area, in the south western as well as in the eastern Baltic Sea, where it is found sympatric with M. neglecta. Allozyme electrophoresis indicated an introduction by range expansion from the North Sea. The second species, M. arctia, was only found in the northern Baltic Sea, where it sometimes occurred sympatric with M. neglecta or M. viridis. For Baltic M. arctia, the most probable way of introduction is by ship ballast water from the European Arctic. There is an urgent need for a new genetic analysis of all Marenzelleria populations of the Baltic Sea to unravel the current distribution of the three species.

  11. Laboratory Culture of Oxyrrhis marina Dujardin%海洋尖尾藻的室内培养

    Institute of Scientific and Technical Information of China (English)

    安鑫龙; 李雪梅; 宫春光


    [目的]研究海洋尖尾藻(Oxrhis marina Dujardin)室内培养的可行性,为其生理生态特性及其赤潮形成机理的研究奠定基础.[方法]在实验室培养海洋尖尾藻,饵料藻为蛋白核小球藻(Chlorella pyrenoidosa)、湛江等鞭金藻(Isochrysis zhangjiangensis)、亚心形扁藻(Platymonas subcordiformis)和绿色巴夫藻(Pavlova viridis).[结果]在实验室条件下,除高密度的蛋白核小球藻和湛江等鞭金藻外,以亚心形扁藻和绿色巴夫藻作为饵料时海洋尖尾藻均能良好地生长和繁殖.[结论]该研究为海洋尖尾藻的室内培养解决了饵料问题,实现了海洋尖尾藻室内的长期培养.%[ Objective ] The research aimed to study the feasibility of laboratory culture of O. Marina Dujardin, to lay foundation for study of its physiological and ecological characteristics and formation mechanism of red tide. [ Method ] Food algae were Chlorella pyrenoidosa, Isochry-sis zhangjiangensis, Platymonas subcordiformis and Pavlova viridis. [ Result] Under the laboratory culture conditions, except of highly dense C. Pyrenoidosa and I. Zhangjiangensis, when P. Subcordiformis and P. Viridis were used as food algae, O. Marina Dujardin could develop and breed well. [ Conclusion ] The study can solve the problem of shortage of food algae when O. Marina Dujardin was cultured in laboratory, realizing the long-term culture of O. Marina Dujardin indoor.

  12. Evolutionary Convergence of Cell-Specific Gene Expression in Independent Lineages of C4 Grasses1[W][OPEN (United States)

    John, Christopher R.; Smith-Unna, Richard D.; Woodfield, Helen; Covshoff, Sarah; Hibberd, Julian M.


    Leaves of almost all C4 lineages separate the reactions of photosynthesis into the mesophyll (M) and bundle sheath (BS). The extent to which messenger RNA profiles of M and BS cells from independent C4 lineages resemble each other is not known. To address this, we conducted deep sequencing of RNA isolated from the M and BS of Setaria viridis and compared these data with publicly available information from maize (Zea mays). This revealed a high correlation (r = 0.89) between the relative abundance of transcripts encoding proteins of the core C4 pathway in M and BS cells in these species, indicating significant convergence in transcript accumulation in these evolutionarily independent C4 lineages. We also found that the vast majority of genes encoding proteins of the C4 cycle in S. viridis are syntenic to homologs used by maize. In both lineages, 122 and 212 homologous transcription factors were preferentially expressed in the M and BS, respectively. Sixteen shared regulators of chloroplast biogenesis were identified, 14 of which were syntenic homologs in maize and S. viridis. In sorghum (Sorghum bicolor), a third C4 grass, we found that 82% of these trans-factors were also differentially expressed in either M or BS cells. Taken together, these data provide, to our knowledge, the first quantification of convergence in transcript abundance in the M and BS cells from independent lineages of C4 grasses. Furthermore, the repeated recruitment of syntenic homologs from large gene families strongly implies that parallel evolution of both structural genes and trans-factors underpins the polyphyletic evolution of this highly complex trait in the monocotyledons. PMID:24676859

  13. Nutrient composition and nutritional importance of green leaves and wild food resources in an agricultural district, Koutiala, in southern Mali. (United States)

    Nordeide, M B; Hatløy, A; Følling, M; Lied, E; Oshaug, A


    This paper discusses the nutrient composition and the nutritional importance of green leaves and wild gathered foods in an area with surplus food production in Mali. In this West African country, there is little information about the nutrient composition and the nutritional quality of foods in general, and of wild gathered foods in particular. Food frequency was collected in two cross-sectional surveys. Focus group discussions with women in the area were used to collect information about seasonality, availability and preparation of various foods. Selected food samples were collected for chemical analysis of nutrient composition. The food samples of green leaves (Adansonia digitata, Amaranthus viridis, Tamarindus indica, Allium cepa), seeds and flour (Parkia biglobosa) and fruits (Tamarindus indica) were analysed for water, energy, fat, protein, minerals, amino acids and carotenoids. Availability and use of the foods varied with seasons. In the rainy season, wild gathered foods (e.g. A. digitata) were used as much as fresh cultivated foods (e.g., A. viridis and A. cepa). The wild food resources were more frequently used in rural than in urban areas, with A. digitata as the dominating green leaves. Green leaves were rich in energy, protein and minerals (calcium, iron). Leaves of A. viridis were, in particular, rich in beta-carotene (3290 micrograms/100 g). Chemical score in dried green leaves varied from 47 (A. cepa) to 81 (A. digitata), with lysine as the first limiting amino acid. P. biglobosa fermented seeds, with 35% fat and 37% protein were a complementary source of lysine in the diet. Based on the seasonality, the frequency of use and the nutrient contents of selected green leaves and wild gathered foods in Koutiala district, it is concluded that these traditional and locally produced foods are valuable and important nutrient contributors in the diet both in rural and urban areas, but most important in rural areas.

  14. Effect of suramin on myotoxicity of some crotalid snake venoms

    Directory of Open Access Journals (Sweden)

    E.Z. Arruda


    Full Text Available We investigated the protective effect of suramin, an enzyme inhibitor and an uncoupler of G protein from receptors, on the myotoxic activity in mice of different crotalid snake venoms (A.c. laticinctus, C.v. viridis, C.d. terrificus, B. jararacussu, B. moojeni, B. alternatus, B. jararaca, L. muta. Myotoxicity was evaluated in vivo by injecting im the venoms (0.5 or 1.0 mg/kg dissolved in physiological saline solution (0.1 ml and measuring plasma creatine kinase (CK activity. Two experimental approaches were used in mice (N = 5 for each group. In protocol A, 1 mg of each venom was incubated with 1.0 mg suramin (15 min, 37ºC, in vitro, and then injected im into the mice at a dose of 1.0 mg/kg (in vivo. In protocol B, venoms, 1.0 mg/kg, were injected im 15 min prior to suramin (1.0 mg/kg, iv. Before and 2 h after the im injection blood was collected by orbital puncture. Plasma was separated and stored at 4ºC for determination of CK activity using a diagnostic kit from Sigma. Preincubation of some venoms (C.v. viridis, A.c. laticinctus, C.d. terrificus and B. jararacussu with suramin reduced (37-76% the increase in plasma CK, except for B. alternatus, B. jararaca or L. muta venoms. Injection of suramin after the venom partially protected (34-51% against the myotoxicity of B. jararacussu, A.c. laticinctus and C.d. terrificus venom, and did not protect against C.v. viridis, L. muta, B. moojeni, B. alternatus or B. jararaca venoms. These results show that suramin has an antimyotoxic effect against some, but not all the North and South American crotalid snake venoms studied here.

  15. Comparison of Arbuscular Mycorrhizal Fungal Community in Roots and Rhizosphere of Invasive Cenchrus incertus and Native Plant in Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    Dan XIANG; Baodong CHEN; Huan LI; Ruojuan LI; Xin ZHANG


    Plant invasions could significantly alter arbuscular mycorrhizal (AM) fungal communities, but the effect may vary with plant species and local environments. Identifying changes in the AM fungal community due to plant invasion could improve our understanding of the invasion processes. Here, we examined the AM fungal community composition both in roots and rhizo-sphere soils of the invasive plant Cenchrus incertus and the dominant native plant Setaria viridis in a typical steppe in Inner Mongolia by using terminal restriction fragment length polymorphism analyses (T-RFLP). The results showed that AM fungal abundance in the rhizosphere soils of C. incertus was significantly lower than that of S. viridis. The AM fungal community com-position in the rhizosphere soils of the two plant species also largely differed. In general, AM fungal community structures in roots corresponded very wel to that in rhizosphere soils for both plant species. The dominant AM fungal type both in invasive and native plants was T-RFLP 524bp, which represents Glomus sp. (Virtual taxa 109 and 287). Three specific T-RF types (280, 190 and 141bp) were significantly more abundant in C. incertus, representing three clusters in Glomus which also named as VT (virtual taxa) 287, 64 and 214, Rhizophagus intraradices (VT 113) and Diversispora sp. (VT 60). While the specific T-RF types, 189 and 279bp, for S. viridis, only existed in Glomus cluster 1 (VT 156), were significantly less abundant in C. incertus. These results indicated that AM fungi might play an important role in the invasion process of C. incertus, which stil remains to be fur-ther investigated.

  16. The alteration of proportion of different lizard species compared to each other at The Great Pasture of Hajdubagos


    Antal, Zsuzsanna


    Three different lizard species can be found at the great pasture of Hajúbagos. These are the balkan or crimean wall lizard (Podarcis taurica), the sand lizard (Lacerta agilis) and the green lizard (Lacerta viridis). All of them are protected by law in Hungary but while sand lizard and green lizard is common all over the country, the amount of the balkan wall lizard is decreasing. The main cause of this regrettable possession is the habitat degradation and thus habitat loss. Namely balkan wall...

  17. A checklist of malacofauna of the Vellar Estuarine Mangroves, India

    Directory of Open Access Journals (Sweden)

    K. Kesavan


    Full Text Available A survey conducted to know the diversity of malacofauna in Vellar estuarine mangroves (southeast coast of India. In this study, 13 species of molluscs (10 species of gastropods - Melampus ceylonicus, Cerithidea cingulata, Cassidula nucleus, Pythia plicata, Neritina (Dostia violacea, Littorina scabra, Littorina melanostoma, Ellobium aurisjudae, C. obtusa T. telescopium and Assiminea nitida and 3 species of bivalves - Perna viridis, Crassostrea madrasensis and Modiolus metcalfei were recorded. M. pulchella, C. obtusa, L. scabra and N. violacea were found arboreal. T. telescopium, C. cingulata and E. aurisjudae were found crawling on the intertidal mud.

  18. Alter ego representations in San Agustin monolithic sculptures: possible plant hallucinogenic influences. (United States)

    de Rios, Marlene Dobkin


    This article examines the evidence for plant hallucinogenic use (possibly Brugmansia, Brunfelsia chiricaspi, Desfontainia R., Anadenanthera peregrina, Banisteriopsis sps, Psychotropia viridis and Virola theidora) by the San Agustin culture, an extinct peoples who resided in the Magdelena River area of Colombia from the third century B.C. until the sixteenth century A.D. Based on thematic materials gathered from a cross-cultural survey of plant hallucinogens, the author examines themes in the monolithic sculptures of this culture in light of man-animal transformations and shamanic themes linked to plant hallucinogenic ingestion.

  19. Algal endosymbiosis in brown hydra: host/symbiont specificity. (United States)

    Rahat, M; Reich, V


    Host/symbiont specificity has been investigated in non-symbiotic and aposymbiotic brown and green hydra infected with various free-living and symbiotic species and strains of Chlorella and Chlorococcum. Morphology and ultrastructure of the symbioses obtained have been compared. Aposymbiotic Swiss Hydra viridis and Japanese H. magnipapillata served as controls. In two strains of H. attenuata stable hereditary symbioses were obtained with Chlorococcum isolated from H. magnipapillata. In one strain of H. vulgaris, in H. oligactis and in aposymbiotic H. viridis chlorococci persisted for more than a week. Eight species of free-living Chlorococcum, 10 symbiotic and 10 free-living strains of Chlorella disappeared from the brown hydra within 1-2 days. In H. magnipapillata there was a graded distribution of chlorococci along the polyps. In hypostomal cells there were greater than 30 algae/cell while in endodermal cells of the mid-section or peduncle less than 10 algae/cell were found. In H. attenuata the algal distribution was irregular, there were up to five chlorocci/cell, and up to 20 cells/hydra hosted algae. In the dark most cells of Chlorococcum disappeared from H. magnipapillata and aposymbiotic hydra were obtained. Chlorococcum is thus an obligate phototroph, and host-dependent heterotrophy is not required for the preservation of a symbiosis. The few chlorococci that survived in the dark seem to belong to a less-demanding physiological strain. In variance with known Chlorella/H. viridis endosymbioses the chlorococci in H. magnipapillata and H. attenuata were tightly enveloped in the vacuolar membrane of the hosting cells with no visible perialgal space. Chlorococcum reproduced in these vacuoles and up to eight daughter cells were found within the same vacuole. We suggest that the graded or scant distribution of chlorococci in the various brown hydra, their inability to live in H. viridis and the inability of the various chlorellae to live in brown hydra are the



    Benoy Kumar Ghosh; Animesh Kumar Datta; Ananya Das; Aninda Mandal


    Fourteen viable macromutants (viridis, lax branching, bushy, unbranched I and II, dark green leaf, broad leaf I and II, narrow leaf I and II, drooping leaf I and II, dwarf and early maturity) were induced in Andrographis paniculata (Burm. F.) Nees (Family: Acanthaceae) at M2 following EMS (Ethyl methanesulfonate) and dES (Diethyl sulfate) treatments (0.25, 0.50 and 1.00% for 2h and 4h durations) to dry seeds (moisture content 11.55%). Mutation frequency over M2 population was 2.82% and lax br...

  1. Anticomplement activity of organic solvent extracts from Korea local Amarantaceae spp. (United States)

    Jung, Seil; Lee, Jai-Heon; Lee, Young-Choon; Moon, Hyung-In


    The study evaluated the anticomplement activity from various solvent extracts of nine Amarantaceae plants (Achyranthes japonica (Miq.) Nakai, Amaranthus mangostanus L., Amaranthus retroflexus L., Amaranthus spinosus L., Celosia argentea var. spicata., Amaranthus lividus L., Celosia cristata L., Amaranthus viridis L., Gomphrena globosa L.) from South Korea on the classical pathway. We have evaluated various organic solvent extract from nine Amarantaceae plants with regard to its anticomplement activity on the classical pathway. Achyranthes japonica chloroform extracts showed inhibitory activity against complement system with 50% inhibitory concentrations (IC(50)) value of 73.1μg/ml. This is the first report of anticomplement activity from Amarantaceae plants.

  2. Bioactivity of Phycocolloids against the Mediterranean Protozoan Leishmania infantum: An Inceptive Study

    Directory of Open Access Journals (Sweden)

    Simona Armeli Minicante


    Full Text Available Sulfated polysaccharides from marine macroalgae have been shown to possess a variety of biological activities against fungi, bacteria, viruses, and protozoa. In this study, the in vitro activity of algal polysaccharides against Leishmania infantum (Kinetoplastida: Trypanosomatidae was investigated. The polysaccharides were extracted from different macroalgae of the Mediterranean Sea: Chaetomorpha linum, Agardhiella subulata, Gracilaria viridis, Gracilaria bursa-pastoris, Hypnea cornuta, Sargassum muticum, and Undaria pinnatifida. Preliminary results showed a good anti-leishmanial activity of the investigated species, encouraging the focus on their use as natural resources in order to match integrated management strategies for the employment of local macroalgae.

  3. Can upwelling signals be detected in intertidal fishes of different trophic levels? (United States)

    Pulgar, J; Poblete, E; Alvarez, M; Morales, J P; Aranda, B; Aldana, M; Pulgar, V M


    For intertidal fishes belonging to three species, the herbivore Scartichthys viridis (Blenniidae), the omnivore Girella laevifrons (Kyphosidae) and the carnivore Graus nigra (Kyphosidae), mass and body size relationships were higher in individuals from an upwelling zone compared with those from a non-upwelling zone. RNA:DNA were higher in the herbivores and omnivores from the upwelling zone. Higher biomass and RNA:DNA in the upwelling intertidal fishes may be a consequence of an increased exposure to higher nutrient availability, suggesting that increased physiological conditioning in vertebrates from upwelling areas can be detected and measured using intertidal fishes of different trophic levels.

  4. Genome sequencing and annotation of Amycolatopsis vancoresmycina strain DSM 44592T

    Directory of Open Access Journals (Sweden)

    Navjot Kaur


    Full Text Available We report the 9.0-Mb draft genome of Amycolatopsis vancoresmycina strain DSM 44592T, isolated from Indian soil sample; produces antibiotic vancoresmycin. Draft genome of strain DSM44592T consists of 9,037,069 bp with a G+C content of 71.79% and 8340 predicted protein coding genes and 57 RNAs. RAST annotation indicates that strains Streptomyces sp. AA4 (score 521, Saccharomonospora viridis DSM 43017 (score 400 and Actinosynnema mirum DSM 43827 (score 372 are the closest neighbors of the strain DSM 44592T.

  5. Shipboard assessment of hearing sensitivity of tropical fishes immediately after exposure to seismic air gun emissions at Scott Reef. (United States)

    Hastings, Mardi C; Miksis-Olds, Jennifer


    This is the first study to examine the potential effects of emissions from an air gun array on hearing of tropical reef fish using AEP thresholds measured in the field. Over 7 days, 51 Chromis viridis,47 Lutjanus kasmira, 20 Myripristis murdjan, and 10 Sargocentron spiniferum were tested. AEP thresholds were determined before and after exposure to emissions from one or two passes of an airgun array. Temporary threshold shift resulting from sound exposure was not found in any species,even when cumulative sound exposure levels reached 190 dB re 1 μPa2-s.

  6. NR4A nuclear receptors mediate carnitine palmitoyltransferase 1A gene expression by the rexinoid HX600

    Energy Technology Data Exchange (ETDEWEB)

    Ishizawa, Michiyasu [Division of Biochemistry, Department of Biomedical Sciences, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610 (Japan); Kagechika, Hiroyuki [Graduate School of Biomedical Science, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Makishima, Makoto, E-mail: [Division of Biochemistry, Department of Biomedical Sciences, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610 (Japan)


    Highlights: Black-Right-Pointing-Pointer The function of RXR heterodimers with NR4 receptors remains unknown. Black-Right-Pointing-Pointer The RXR ligand HX600 induces expression of carnitine palmitoyltransferase 1A (CPT1A). Black-Right-Pointing-Pointer HX600-induced CPT1A expression is mediated by the NR4 receptors, Nur77 and NURR1. Black-Right-Pointing-Pointer CPT1A induction by HX600 is not mediated by de novo protein synthesis. Black-Right-Pointing-Pointer CPT1A could be a target of the Nur77-RXR and NURR1-RXR heterodimers. -- Abstract: Retinoid X receptors (RXRs) are members of the nuclear receptor superfamily and can be activated by 9-cis retinoic acid (9CRA). RXRs form homodimers and heterodimers with other nuclear receptors such as the retinoic acid receptor and NR4 subfamily nuclear receptors, Nur77 and NURR1. Potential physiological roles of the Nur77-RXR and NURR1-RXR heterodimers have not been elucidated. In this study, we identified a gene regulated by these heterodimers utilizing HX600, a selective RXR agonist for Nur77-RXR and NURR1-RXR. While 9CRA induced many genes, including RAR-target genes, HX600 effectively induced only carnitine palmitoyltransferase 1A (CPT1A) in human teratocarcinoma NT2/D1 cells, which express RXR{alpha}, Nur77 and NURR1. HX600 also increased CPT1A expression in human embryonic kidney (HEK) 293 cells and hepatocyte-derived HepG2 cells. Although HX600 induced CPT1A less effectively than 9CRA, overexpression of Nur77 or NURR1 increased the HX600 response to levels similar to 9CRA in NT2/D1 and HEK293 cells. A dominant-negative form of Nur77 or NURR1 repressed the induction of CPT1A by HX600. A protein synthesis inhibitor did not alter HX600-dependent CPT1A induction. Thus, the rexinoid HX600 directly induces expression of CPT1A through a Nur77 or NURR1-mediated mechanism. CPT1A, a gene involved in fatty acid {beta}-oxidation, could be a target of RXR-NR4 receptor heterodimers.

  7. Possible Role of Interference and Sink Effects in Nonphotochemical Quenching in Photosynthetic Complexes

    CERN Document Server

    Berman, Gennady P; Gurvitz, Shmuel; Sayre, Richard T


    We describe a simple and consistent quantum mathematical model that simulates the possible role of quantum interference and sink effects in the nonphotochemical quenching (NPQ) in light-harvesting complexes (LHCs). Our model consists of a network of five interconnected sites (excitonic states) responsible for the NPQ mechanism: (i) Two excited states of chlorophyll molecules, $ChlA^*$ and $ChlB^*$, forming an LHC dimer, which is initially populated; (ii) A "damaging" site which is responsible for production of singlet oxygen and other destructive outcomes; (iii) The $(ChlA-Zea)^*$ heterodimer excited state (Zea indicates zeaxanthin); and (iv) The charge transfer state of this heterodimer, $(ChlA^{-}-Zea^{+})^*$. In our model, both damaging and charge transfer states are described by discrete electron energy levels attached to their sinks, that mimic the continuum part of electron energy spectrum, as at these sites the electron participates in quasi-irreversible chemical reactions. All five excitonic sites int...

  8. Colloidosome-based synthesis of a multifunctional nanostructure of silver and hollow iron oxide nanoparticles

    KAUST Repository

    Pan, Yue


    Nanoparticles that self-assemble on a liquid-liquid interface serve as the building block for making heterodimeric nanostructures. Specifically, hollow iron oxide nanoparticles within hexane form colloidosomes in the aqueous solution of silver nitrate, and iron oxide exposed to the aqueous phase catalyzes the reduction of silver ions to afford a heterodimer of silver and hollow iron oxide nanoparticles. Transmission electron microscopy, selected area electron diffraction, energy-dispersive X-ray spectrometry, X-ray diffraction, UV-vis spectroscopy, and SQUID were used to characterize the heterodimers. Interestingly, the formation of silver nanoparticles helps the removal of spinglass layer on the hollow iron oxide nanoparticles. This work demonstrates a powerful yet convenient strategy for producing sophisticated, multifunctional nanostructures. © 2010 American Chemical Society.

  9. Beta1 integrins differentially control extravasation of inflammatory cell subsets into the CNS during autoimmunity

    DEFF Research Database (Denmark)

    Bauer, Martina; Brakebusch, Cord; Coisne, Caroline;


    Inhibiting the alpha(4) subunit of the integrin heterodimers alpha(4)beta(1) and alpha(4)beta(7) with the monoclonal antibody natalizumab is an effective treatment for multiple sclerosis (MS). However, the pharmacological action of natalizumab is not understood conclusively. Previous studies...... suggested that natalizumab inhibits activation, proliferation, or extravasation of inflammatory cells. To specify which mechanisms, cell types, and alpha(4) heterodimers are affected by the antibody treatment, we studied MS-like experimental autoimmune encephalomyelitis (EAE) in mice lacking the beta(1......)-integrin gene either in all hematopoietic cells or selectively in T lymphocytes. Our results show that T cells critically rely on beta(1) integrins to accumulate in the central nervous system (CNS) during EAE, whereas CNS infiltration of beta(1)-deficient myeloid cells remains unaffected, suggesting that T...

  10. Nonlinear Dynamics of Dipoles in Microtubules: Pseudo-Spin Model

    CERN Document Server

    Nesterov, Alexander I; Berman, Gennady P; Mavromatos, Nick E


    We perform a theoretical study of the dynamics of the electric field excitations in a microtubule by taking into consideration the realistic cylindrical geometry, dipole-dipole interactions of the tubulin-based protein heterodimers, the radial electric field produced by the solvent, and a possible degeneracy of energy states of individual heterodimers. The consideration is done in the frames of the classical pseudo-spin model. We derive the system of nonlinear dynamical ordinary differential equations of motion for interacting dipoles, and the continuum version of these equations. We obtain the solutions of these equations in the form of snoidal waves, solitons, kinks, and localized spikes. Our results will help to a better understanding of the functional properties of microtubules including the motor protein dynamics and the information transfer processes. Our considerations are based on classical dynamics. Some speculations on the role of possible quantum effects are also made.

  11. Slit-Robo signaling in ocular angiogenesis. (United States)

    Chen, Haoyu; Zhang, Mingzhi; Tang, Shibo; London, Nyall R; Li, Dean Y; Zhang, Kang


    Slit-Robo signaling was firstly discovered as a major repellent pathway at the midline of the central nervous system. Intense investigation found that this pathway also plays an important role in other biological process including angiogenesis. Robo4 is the vascular endothelial cell specific member of Robo family. It was found that Slit-Robo signaling can inhibit endothelial cell migration, tube formation and vascular permeability. Slit-Robo signaling also plays an important role in embryonic and tumor angiogenesis. In animal model of ocular angiogenesis, addition of Slit inhibited laser induced choroidal neovascularization, oxygen induced retinopathy and VEGF induced retinal permeability in a Robo4 dependent manner. Recent data demonstrates that Robo1 and Robo4 form a heterodimer in endothelial cells, The role of this heterodimer in counteracting VEGF signaling is unknown. Further investigation is required to better understand Slit-Robo signaling and develop novel therapy for angiogenesis.

  12. Suppression of OsKu80 results in defects in developmental growth and increased telomere length in rice (Oryza sativa L.). (United States)

    Byun, Mi Young; Cui, Li Hua; Kim, Woo Taek


    The Ku70-Ku80 heterodimer plays a critical role in the maintenance of genomic stability in humans and yeasts. In this report, we identified and characterized OsKu80 in rice, a model monocot crop. OsKu80 forms a heterodimer with OsKu70 in yeast and plant cells, as demonstrated by yeast two-hybrid, in vivo co-immunoprecipitation, and bimolecular fluorescence complementation assays. RNAi-mediated knock-down T3 transgenic rice plants (Ubi:RNAi-OsKu80) displayed a retarded growth phenotype at the post-germination stage. In addition, the Ubi:RNAi-OsKu80 knock-down progeny exhibited noticeably increased telomere length as compared to wild-type rice. These results are discussed with the idea that OsKu80 plays a role in developmental growth and telomere length regulation in rice plants.

  13. Identification of peroxisome-proliferator responsive element in the mouse HSL gene. (United States)

    Yajima, Hiroaki; Kobayashi, Yumie; Kanaya, Tomoka; Horino, Yoko


    Hormone-sensitive lipase (HSL) catalyzes the rate-limiting step of lipolysis in adipose tissue. Several studies suggest that protein phosphorylation regulates the HSL enzymatic activity. On the other hand, the precise mechanism of the transcriptional regulation of the HSL gene remains to be elucidated. Here, we identified a functional peroxisome-proliferator responsive element (PPRE) in the mouse HSL promoter by reporter assay in CV-1 cells using serial deletion and point mutants of the 5'-flanking region. Chromatin immunoprecipitation (ChIP) analysis revealed that both peroxisome-proliferator activated receptor (PPARgamma) and retinoid X receptor (RXRalpha) interacted with the region. Binding of the PPARgamma/RXRalpha heterodimer to the PPRE sequence was also confirmed by electrophoretic mobility shift assay. These results indicate that the HSL gene is transcriptionally regulated by PPARgamma/RXRalpha heterodimer, and suggest that a cis-acting element regulates the HSL gene expression.

  14. Crystallographic Studies of Cephalosporin Acylase from Pseudomonas sp. Strain 130

    Institute of Scientific and Technical Information of China (English)

    DING Yi(丁怡); JIANG Weihong(姜卫红); ZHANG Shuping(张淑平); MAO Xiang(茅翔); Mark Bartlam; ZHAO Guoping(赵国平); RAO Zihe(饶子和)


    The cephalosporin acylases are a group of enzymes that hydrolyze cephalosporin C and/or glutaryl 7-aminocephalosporanic acid to produce 7-aminocephalosporanic acid.The cephalosporin acylase from Pseudomonas sp.strain 130 was crystallized in two different forms suitable for structural studies.A tetragonal crystal form diffracted to 0.24 nm belonged to the space group P41212.There was one αβ heterodimer per asymmetric unit.A second crystal form diffracted to 0.21 nm belonged to the space group P21.There was four αβ heterodimers per asymmetric unit.The tetragonal crystal structure of CA-130 was determined using the multiwavelength anomalous diffraction method and the P21 crystal structure was then determined using the molecular replacement method.

  15. Sumoylation of SAE2 C terminus regulates SAE nuclear localization. (United States)

    Truong, Khue; Lee, Terry D; Li, Baozong; Chen, Yuan


    SUMOylation occurs predominantly in the nucleus, but non-nuclear proteins can also be SUMOylated. It is unclear how intracellular trafficking of the SUMOylation enzymes is regulated to catalyze SUMOylation in different cellular compartments. Here we report that the SAE2 subunit of human SUMO activation enzyme (SAE) underwent rapid nucleocytoplasmic shuttling and its nuclear accumulation depended on SUMO modification at the C terminus. The SUMOylation sites included three Lys residues on the bipartite nuclear localization sequence (NLS) and two Lys residues outside of but adjacent to the NLS, and their SUMOylation was catalyzed by Ubc9. Because SAE2 forms a tight heterodimer with SAE1 and it controls the trafficking of the heterodimer, this study has identified the mechanism used to localize SAE to the nucleus. Similar mechanisms are likely to exist for other proteins that depend on SUMOylation for nuclear localization.

  16. Molecular basis for manganese sequestration by calprotectin and roles in the innate immune response to invading bacterial pathogens. (United States)

    Damo, Steven M; Kehl-Fie, Thomas E; Sugitani, Norie; Holt, Marilyn E; Rathi, Subodh; Murphy, Wesley J; Zhang, Yaofang; Betz, Christine; Hench, Laura; Fritz, Günter; Skaar, Eric P; Chazin, Walter J


    The S100A8/S100A9 heterodimer calprotectin (CP) functions in the host response to pathogens through a mechanism termed "nutritional immunity." CP binds Mn(2+) and Zn(2+) with high affinity and starves bacteria of these essential nutrients. Combining biophysical, structural, and microbiological analysis, we identified the molecular basis of Mn(2+) sequestration. The asymmetry of the CP heterodimer creates a single Mn(2+)-binding site from six histidine residues, which distinguishes CP from all other Mn(2+)-binding proteins. Analysis of CP mutants with altered metal-binding properties revealed that, despite both Mn(2+) and Zn(2+) being essential metals, maximal growth inhibition of multiple bacterial pathogens requires Mn(2+) sequestration. These data establish the importance of Mn(2+) sequestration in defense against infection, explain the broad-spectrum antimicrobial activity of CP relative to other S100 proteins, and clarify the impact of metal depletion on the innate immune response to infection.

  17. Positive Control Mutations in the MyoD Basic Region Fail to Show Cooperative DNA Binding and Transcriptional Activation in vitro (United States)

    Bengal, Eyal; Flores, Osvaldo; Rangarajan, Pundi N.; Chen, Amy; Weintraub, Harold; Verma, Inder M.


    An in vitro transcription system from HeLa cells has been established in which MyoD and E47 proteins activate transcription both as homodimers and heterodimers. However, heterodimers activate transcription more efficiently than homodimers, and function synergistically from multiple binding sites. Positive control mutants in the basic region of MyoD that have previously been shown to be defective in initiating the myogenic program, can bind DNA but have lost their ability to function as transcriptional activators in vitro. Additionally, positive control mutants, unlike wild-type MyoD, fail to bind cooperatively to DNA. We propose that binding of MyoD complexes to high affinity MyoD binding sites induces conformational changes that facilitate cooperative binding to multiple sites and promote transcriptional activation.

  18. Nonlinear dynamics of dipoles in microtubules: Pseudospin model. (United States)

    Nesterov, Alexander I; Ramírez, Mónica F; Berman, Gennady P; Mavromatos, Nick E


    We perform a theoretical study of the dynamics of the electric field excitations in a microtubule by taking into consideration the realistic cylindrical geometry, dipole-dipole interactions of the tubulin-based protein heterodimers, the radial electric field produced by the solvent, and a possible degeneracy of energy states of individual heterodimers. The consideration is done in the frame of the classical pseudospin model. We derive the system of nonlinear dynamical partial differential equations of motion for interacting dipoles and the continuum version of these equations. We obtain the solutions of these equations in the form of snoidal waves, solitons, kinks, and localized spikes. Our results will help to achieve a better understanding of the functional properties of microtubules including the motor protein dynamics and the information transfer processes. Our considerations are based on classical dynamics. Some speculations on the role of possible quantum effects are also made.

  19. The transcription factor Rbf1 is the master regulator for b-mating type controlled pathogenic development in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Kai Heimel

    Full Text Available In the phytopathogenic basidiomycete Ustilago maydis, sexual and pathogenic development are tightly connected and controlled by the heterodimeric bE/bW transcription factor complex encoded by the b-mating type locus. The formation of the active bE/bW heterodimer leads to the formation of filaments, induces a G2 cell cycle arrest, and triggers pathogenicity. Here, we identify a set of 345 bE/bW responsive genes which show altered expression during these developmental changes; several of these genes are associated with cell cycle coordination, morphogenesis and pathogenicity. 90% of the genes that show altered expression upon bE/bW-activation require the zinc finger transcription factor Rbf1, one of the few factors directly regulated by the bE/bW heterodimer. Rbf1 is a novel master regulator in a multilayered network of transcription factors that facilitates the complex regulatory traits of sexual and pathogenic development.

  20. AcsA-AcsB: The core of the cellulose synthase complex from Gluconacetobacter hansenii ATCC23769. (United States)

    McManus, John B; Deng, Ying; Nagachar, Nivedita; Kao, Teh-hui; Tien, Ming


    The gram-negative bacterium, Gluconacetobacter hansenii, produces cellulose of exceptionally high crystallinity in comparison to the cellulose of higher plants. This bacterial cellulose is synthesized and extruded into the extracellular medium by the cellulose synthase complex (CSC). The catalytic component of this complex is encoded by the gene AcsAB. However, several other genes are known to encode proteins critical to cellulose synthesis and are likely components of the bacterial CSC. We have purified an active heterodimer AcsA-AcsB from G. hansenii ATCC23769 to homogeneity by two different methods. With the purified protein, we have determined how it is post-translationally processed, forming the active heterodimer AcsA-AcsB. Additionally, we have performed steady-state kinetic studies on the AcsA-AcsB complex. Finally through mutagenesis studies, we have explored the roles of the postulated CSC proteins AcsC, AcsD, and CcpAx.

  1. "Bis-Click" Ligation of DNA: Template-Controlled Assembly, Circularisation and Functionalisation with Bifunctional and Trifunctional Azides. (United States)

    Yang, Haozhe; Seela, Frank


    Ligation and circularisation of oligonucleotides containing terminal triple bonds was performed with bifunctional or trifunctional azides. Both reactions are high yielding. Template-assisted bis-click ligation of two individual non-complementary oligonucleotide strands was accomplished to yield heterodimers exclusively. In this context, the template fulfils two functions: it accelerates the ligation reaction and controls product assembly (heterodimer vs. homodimer formation). Intermolecular bis-click circularisation of one oligonucleotide strand took place without template assistance. For construction of oligonucleotides with terminal triple bonds in the nucleobase side chain, 7- or 5-functionalised 7-deaza-dA and dU residues were used. These oligonucleotides are directly accessible by solid-phase synthesis. When trifunctional azides were employed instead of bifunctional linkers, functionalisation of the remaining azido group was performed with small molecules such as 1-ethynyl pyrene, biotin propargyl amide or with ethynylated oligonucleotides. By this means, branched DNA was constructed.

  2. Ab initio study of 1:1 complexes of nitrogen trifluoride with nitrous oxide and carbon dioxide in vacuo

    Indian Academy of Sciences (India)

    Abdolvahab Seif; R Bagherzadeh; Moein Goodarzi; Khaled Azizi


    Quantum chemical calculations are carried out in order to investigate the heterodimers of NF3 with isoelectronic and isostructure species of N2O and CO2 in gas phase within the MP2 (Møller-Plesset perturbation) and CCSD(T) levels. Three and four minima are located on the potential energy surfaces of NF3-CO2 and NF3-N2O systems at the MP2/aug-cc-PVDZ level, respectively. Single-point energy calculations at the MP2/aug-cc-PVTZ and CCSD(T)/aug-cc-PVDZ levels confirm results obtained at the MP2/aug-cc-PVDZ level show that atmospheric roles of NF3-N2O and NF3-CO2 systems are similar. The atom in molecules theory was applied to analyse the nature of intermolecular interactions. Also, natural bond orbital (NBO) analysis has been used in order to obtain charge transfer quota among heterodimers.

  3. A monomeric G protein-coupled receptor isolated in a high-density lipoprotein particle efficiently activates its G protein

    DEFF Research Database (Denmark)

    Whorton, Matthew R; Bokoch, Michael P; Rasmussen, Søren Gøgsig Faarup;


    G protein-coupled receptors (GPCRs) respond to a diverse array of ligands, mediating cellular responses to hormones and neurotransmitters, as well as the senses of smell and taste. The structures of the GPCR rhodopsin and several G proteins have been determined by x-ray crystallography, yet...... the organization of the signaling complex between GPCRs and G proteins is poorly understood. The observations that some GPCRs are obligate heterodimers, and that many GPCRs form both homo- and heterodimers, has led to speculation that GPCR dimers may be required for efficient activation of G proteins. However......, technical limitations have precluded a definitive analysis of G protein coupling to monomeric GPCRs in a biochemically defined and membrane-bound system. Here we demonstrate that a prototypical GPCR, the beta2-adrenergic receptor (beta2AR), can be incorporated into a reconstituted high-density lipoprotein...

  4. Enthalpies and entropies of vaporization of propan-2-ol-2-methylpropan-1-ol solutions (United States)

    Baev, A. A.; Baev, A. K.


    P-T-x dependences are measured for the solutions of a propan-2-ol-2-methylpropan-1-ol binary system and the enthalpies and entropies of vaporization are determined. Dimerization in propan-2-ol and 2-methylpropan-1-ol is rationalized and the contribution from energy introduced by isostructural methyl groups to the enthalpy of vaporization is determined. Structural and energy analyses of solutions with networks of specific interactions are performed. The formation of heterodimers in solutions and vapors with reduced hydrogen bond energies and specific interactions with the 2 s 2(C) unshared electron pairs of the carbon atoms of terminal methyl groups in ethyl and propyl fragments of propan-2-ol and 2-methylpropan-1-ol, respectively, is substantiated. The hydrogen bond energy of heterodimers is estimated.

  5. Mussel adhesion is dictated by time-regulated secretion and molecular conformation of mussel adhesive proteins (United States)

    Petrone, Luigi; Kumar, Akshita; Sutanto, Clarinda N.; Patil, Navinkumar J.; Kannan, Srinivasaraghavan; Palaniappan, Alagappan; Amini, Shahrouz; Zappone, Bruno; Verma, Chandra; Miserez, Ali


    Interfacial water constitutes a formidable barrier to strong surface bonding, hampering the development of water-resistant synthetic adhesives. Notwithstanding this obstacle, the Asian green mussel Perna viridis attaches firmly to underwater surfaces via a proteinaceous secretion (byssus). Extending beyond the currently known design principles of mussel adhesion, here we elucidate the precise time-regulated secretion of P. viridis mussel adhesive proteins. The vanguard 3,4-dihydroxy-L-phenylalanine (Dopa)-rich protein Pvfp-5 acts as an adhesive primer, overcoming repulsive hydration forces by displacing surface-bound water and generating strong surface adhesion. Using homology modelling and molecular dynamics simulations, we find that all mussel adhesive proteins are largely unordered, with Pvfp-5 adopting a disordered structure and elongated conformation whereby all Dopa residues reside on the protein surface. Time-regulated secretion and structural disorder of mussel adhesive proteins appear essential for optimizing extended nonspecific surface interactions and byssus' assembly. Our findings reveal molecular-scale principles to help the development of wet-resistant adhesives.

  6. Studies on mutagenic effectiveness and efficiency of gamma rays and its effect on quantitative traits in finger millet (Eleusine coracana L. Gaertn

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    A.R. Ambavane


    Full Text Available Dry seeds (12% moisture of two finger millet cultivar viz., Dapoli-1 and Dapoli Safed were irradiated with four doses of gamma-rays viz., 400 Gy, 500 Gy, 600 Gy and 700 Gy at BARC, Mumbai. In laboratory test, root and shoot lengths of seedlings were decreased with increase in dose of gamma rays. Similarly, germination percentage and survival rate of seedlings were decreased with increase in dose of gamma irradiation during field study. In M1 generation, three types of chlorophyll mutations viz., albino, xantha and viridis were observed. Albino and xantha were observed in all treatments, whereas, viridis observed only in lower doses viz., 400 Gy and 500 Gy. Based on the chlorophyll mutation frequency on M1 plants, mutagenic effectiveness and efficiency were computed. In Dapoli-1 variety, two early maturing mutants and three high yielding mutants were isolated from 500 Gy dose and 600 Gy dose, respectively. In M2 generation, the mutagenic treatments were effective in inducing various types of chlorophyll and morphological macro mutants, few of those show significant change in flowering, maturity and plant height character and few of them have good breeding value.

  7. Anti-diabetic and anti-cholesterolemic activity of methanol extracts of three species ofAmaranthus

    Institute of Scientific and Technical Information of China (English)

    Girija K; Lakshman K; Udaya Chandrika; Sabhya Sachi Ghosh; Divya T


    Objective:To investigate the anti-diabetic and anti-cholesterolemic activity of methanol extracts of leaves ofAmaranthus caudatus,Amaranthus spinosus andAmaranthus viridis in normal and streptozotocin (STZ) induced diabetic rats.Methods:In this study, the anti-diabetic and anti-cholesterolemic activity of methanol extracts of leaves of all three plants was evaluated by using normal andSTZ induced diabetic rats at a dose of200 mg/kg and400 mg/kg p.o.daily for21days. Blood glucose levels and body weight were monitored at specific intervals, and different biochemical parameters, serum cholesterol, serum triglyceride, high density lipoprotein, low density lipoprotein and very low density lipoprotein were also assessed in the experimental animals. Histology of pancreas was performed.Results:It was found that all the three plants at 400 mg/kg dose showed significant anti-diabetic and anti-cholesterolemic activity (P<0.01), while at200 mg/kg dose less significant anti-diabetic activity (P<0.05) was observed.Conclusions:Methanol extracts ofAmaranthus caudatus,Amaranthus spinosus andAmaranthus viridis showed significant anti-diabetic and anti-cholesterolemic activity, which provides the scientific proof for their traditional claims.

  8. Contribuição para o estudo dos Rhinotragini (Coleoptera, Cerambycidae: I. mudança de status nos subgêneros de Ommata white, 1855 e revisão de Agaone Pascoe, 1859

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    Ubirajara R Martins


    Full Text Available Todos os subgêneros de Ommata são elevados a gênero, levando-se em consideração a diversidade de caracteres encontrados em cada um deles. Agaone é revisto e uma nova espécie é descrita do Brasil (Minas Gerais, Espírito Santo, Rio de Janeiro: A. punctilla sp. nov. Cantharoxylymna Linsley, 1934 é considerado sinônimo junior de Agaone. Grupiara gen. nov. é descrito para alocar Ommata (Agaone viridis Gounelle, 1911.Contribution to the study of Rhinotragini (Coleoptera, Cerambycidae. I. Change in the status of the subgenera of Ommata White, 1855, and revision of Agaone Pascoe, 1859. All subgenera of Ommata are elevated to genera regarding the diversity of characters found in each one. Agaone is reviewed, and a new species described: A. punctilla sp. nov. from Brazil (Minas Gerais, Espírito Santo, Rio de Janeiro. Cantharoxylymna Linsley, 1934 is considered a junior synonym of Agaone. Grupiara gen. nov. is described to allocate Ommata (Agaone viridis Gounelle, 1911.

  9. Novos Cerambycinae neotropicais e transferência de Tippmannia Monné para Hesperophanini (Coleoptera, Cerambycidae New Neotropical Cerambycinae and transference of Tippmannia Monné to Hesperophanini (Coleoptera, Cerambycidae

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    Ubirajara R. Martins


    Full Text Available Os seguintes novos táxons neotropicais de Cerambycinae são descritos: em Hesperophanini, Corupella gen. nov., espécie-tipo C. asperata sp. nov. (Brasil; em Graciliini, Aruama gen. nov., espécie-tipo A. viridis sp. nov. (Bolívia e A. incognita sp. nov. (Brasil; em Necydalopsini, Abaiba gen. nov., espécie-tipo A. dimorphica sp. nov. (Bolívia; em Heteropsini, Unatara gen. nov., espécie-tipo U. atinga sp. nov. (Colombia. Transfere-se Tippmannia Monné, 2006 de incertae sedis para Hesperophanini.The following new taxa of Cerambycinae are described: in Hesperophanini, Corupella gen. nov., type species C. asperata sp. nov. (from Brazil; in Graciliini, Aruama gen. nov., type species A. viridis sp. nov. (from Bolívia and A. incognita sp. nov. (from Brazil; in Necydalopsini, Abaiba gen. nov., type species A. dimorphica sp. nov. (from Bolívia; in Heteropsini, Unatara gen. nov., type species. U. atinga sp. nov. (from Colombia. Tippmannia Monné, 2006 is transferred from incertae sedis to Hesperophanini.

  10. Temperature, but not available energy, affects the expression of a sexually selected ultraviolet (UV colour trait in male European green lizards.

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    Katalin Bajer

    Full Text Available BACKGROUND: Colour signals are widely used in intraspecific communication and often linked to individual fitness. The development of some pigment-based (e.g. carotenoids colours is often environment-dependent and costly for the signaller, however, for structural colours (e.g. ultraviolet [UV] this topic is poorly understood, especially in terrestrial ectothermic vertebrates. METHODOLOGY/PRINCIPAL FINDINGS: In a factorial experiment, we studied how available energy and time at elevated body temperature affects the annual expression of the nuptial throat colour patch in male European green lizards (Lacerta viridis after hibernation and before mating season. In this species, there is a female preference for males with high throat UV reflectance, and males with high UV reflectance are more likely to win fights. We found that (i while food shortage decreased lizards' body condition, it did not affect colour development, and (ii the available time for maintaining high body temperature affected the development of UV colour without affecting body condition or other colour traits. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that the expression of a sexually selected structural colour signal depends on the time at elevated body temperature affecting physiological performance but not on available energy gained from food per se in an ectothermic vertebrate. We suggest that the effect of high ambient temperature on UV colour in male L. viridis makes it an honest signal, because success in acquiring thermally favourable territories and/or effective behavioural thermoregulation can both be linked to individual quality.

  11. The effect of chlorsulfurone and MCPB-Na on the enzymatic activity of microorganisms

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    Filimon Marioara Nicoleta


    Full Text Available herbicides, have a broad spectrum effect on weeds, in relatively low doses and with a much reduced toxicity on livestock. In this study were used two herbicides: dacsulfuron with the active substance chlorsulfuron (0.005 - 0.035 μg/g soil and butoxone with the active substance MCPB-Na (0.005 - 0.035 mg/L/g soil. The samples were collected from a depth of 0-20 cm from chernozem soil. The effect of herbicide was estimated by measuring the activity of catalase, actual and potential dehydrogenase, urease and cellulase activities. All samples being incubated for 10 days at 27°C using Sapp medium for isolation and study of cellulosolytic bacteria. The inhibitory effect of the tested herbicides was the most intense for the urease and dehydrogenase enzymatic activities. The most resistant cellulosolytic bacteria to the effects of dacsulfuron were Cellfalcicula fusca, Cellfalcicula viridis, Cellvibrio fulvus and Fuseaux veris and for butoxone Cellfalcicula mucosa, C. viridis and C. fulvus.

  12. New records of tardigrades(Tardigrada) from Taiwan%台湾缓步动物(缓步动物门)新纪录种记述

    Institute of Scientific and Technical Information of China (English)

    阴环; 李晓晨


    报道了采自台湾的缓步动物(缓步动物门)的7个新纪录种.这些缓步动物属于2纲、3目、4科、5属,它们是翠绿棘甲熊虫Echiniscus viridisMurray、苏氏假棘甲熊虫Pseudechiniscus suillus(Ehrenberg)、凯氏米氏熊虫Milnesium katarzynae Kaczmarek et al.、山地大生熊虫Macrobiotus montanus Murray、瑞氏大生熊虫Macrobiotus richtersi Murray、吉伯具矛熊虫Doryphoribius%Seven new record species of tardigrades(Phylum Tardigrada) from Taiwan are reported.They belong to two classes,three orders,four families and five genera.They are Echiniscus viridis Murray,Pseudechiniscus suillus(Ehrenberg),Milnesium katarzynae Kaczmarek,Michalczyk Beasley,Macrobiotus montanus Murray,Macrobiotus richtersi Murray,Doryphoribius gibber Beasley Pilato,and Doryphoribius zappalai Pilato.A key to Taiwanese species of the tardirada is also given.

  13. Systematics and biology of Xylocopa subgenus Schonnherria (Hymenoptera, Apidae) in Argentina (United States)

    Lucia, Mariano; Gonzalez, Victor H.; Abrahamovich, Alberto H.


    Abstract Biological information on the species of the large carpenter bee Xylocopa subgenus Schonnherria occurring in Argentina is revised. Based on the appraisal of museum specimens, the study of type material, and field surveys conducted across 15 provinces between 2007 and 2011, the following seven species are recognized for the country: Xylocopa bambusae Schrottky, Xylocopa chrysopoda Schrottky, Xylocopa macrops Lepeletier de Saint Fargeau, Xylocopa simillima Smith Xylocopa splendidula Lepeletier de Saint Fargeau, Xylocopa pulchra Smith, and Xylocopa viridis Smith. Previous literature records of Xylocopa dimidiata Latreille, Xylocopa subcyanea Pérez, and Xylocopa varians Smith for the province of Misiones appear to have been misidentified specimens, although the presence of these species in Argentina cannot be entirely ruled out given the proximity of this province to Brazil and Paraguay where they occur; Xylocopa boops Maidl was described from a male specimen with unusually enlarged eyes and is newly synonymized under Xylocopa macrops. Males and females of all species are diagnosed, described, and figured, including details of the male genitalia. Taxonomic comments, data on the geographical distribution and nesting substrates, and identification keys to all Argentinean species of Schonnherria are provided. The nesting biologies of Xylocopa splendidula and Xylocopa viridis are documented. PMID:26798288

  14. A Systems Evaluation of the Environmental Impact of the Aubrey Reservoir Project on Elm Fork of the Trinity River in North Texas. (United States)


    viridis 5 3 1 Morus rubra 13 1 Ulmus americana 2 2 Maclura pomifera 2 Cercis canadensis 6 Acer negundo 1 1 Carya illinoensis 1 Ulmus alata 9 Ulmus rubra... Carya illinoensis 4.6 0 0.0 0.1 Ulmus alata 0.4 0.4 13.6 0 0.0 0.4 Ulmus rubra 0.3 0.4 4.6 0 0.0 0.1 q .4 228 Y I Table 17. The species of trees found...viridis 0.3 1.0 13.6 7.2 0.8 1.1 Cercis canadensis 0.1 0.3 9.1 4.4 0.5 0.4 Ulmus rubra 0.1 0.3 4.6 3.2 0.4 0.4 Carya illinoensis 0.2 4.6 7.5 0.9 0.2 229

  15. Parasitóides Associados a Cochonilhas e Aleirodídeos (Sternorrhyncha de Plantas Cítricas no Estado do Rio de Janeiro

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    William Rodrigues


    Abstract. With the purpose of knowing parasitids of scales and whiteflies, associates to the citrus plants in Rio de Janeiro State, they were accomplished leaves collected contend fitoparasits: Aleurothrixus floccosus (Maskell, Tetraleurodes (=Aleurotrachelus cruzi (Cassino, Paraleyrodes bondari Peracchi, Coccus viridis (Green, Crysomphalus ficus (Ashmead, Orthezia praelonga (Douglas and Pinnaspis aspidistrae (Signoret, being this ones clean, it soon after proceded the organism elimination that was study object (each leaf remained with an only species of fitoparasite, so that parasitoids that had arisen had gone same associate to that species. After this procedure the leaves were incubate for a period of 25 days, when it was observed only parasitism in A. floccosus, P. aspidistrae, C. viridis and T. cruzi, and parasitoids of this the latter, not identified because the number specimens was very reduced. It was parasiting A. floccosus it observed: Arrhenophagus sp., Cales sp., Encarsia sp. (1, Eretmocerus sp., Signiphora sp. (1, Signiphora sp. (2, Signiphora sp. (3 and a species of the family Platygasteridae. Parasiting P. aspidistrae it was observed: Arrhenophagus sp., Cales sp., Encarsia sp. (2 and Pteroptrix sp. Some species are associated either to A. floccosus or to P. aspidistrae. By the results it was verified that Arrhenophagus sp. the parasitism and the species of the family Platygasteridae in A. floccosus and parasitism of Arrhenophagus sp. and Pteroptrix sp. in P. aspidistrae, they are occurrence new record for do Rio de Janeiro State

  16. Reducing Insects Contaminations through Stored Foodstuffs by Use of Packaging and Repellency Essential Oils

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    Full Text Available Protection of stored agricultural products against insects is carried out with chemical insecticides. They have harmful effects for human being, animal and environment. This research carried out on plant essential oils, which are one of the harmless materials and act like contact-fumigant from offering the prospect for using in stored product. They should have the ability to repel the insects. The objective of the present study was to test the properties of Prunus amygdalus L. and Mentha viridis L. for preventing the penetration of pest insects, including: T. castaneum, S. granaries, S. paniceum and R. dominica, to packaged cereals. As foodstuff was packaged by PE polymer and placed into a container 10 g of wheat and flour. The repellent essential oils used in the interior surface of containers. The releasing of insects carried out around the containers to determinate the insect�s penetration percentage with effect of repellents. The highest concentration counted was 1.75 ?l of essential oil per 0.5 ml acetone. The results showed that P. amygdalus had the most repellency effect on T. castaneum that cause 78.52% contamination deduction inside the packaged crop in comparing with control. In addition, M. viridis caused the most repellency on S. granarius (63.81%. The results demonstrated the efficacy of these essential oils for using it in organic food protection. They can prevent the infestation of the stored-product pests to the warehouse.


    Kowalczuk, Anna Paulina; Łozak, Anna; Kiljan, Monika; Mętrak, Krystyna; Zjawiony, Jordan Kordian


    Drug market changes dynamically causing many analytical challenges for police experts. Among illicit substances there are synthetic designer products but also herbal material. Plant material is usually in fine-cut or powdered form, thus difficult to identify. For such fragmented material classic taxonomical identification methods using anatomical and morphological features of the plant cannot be employed. The aim of the study was to develop an identification method of the powdered material with employment of multidimensional data analysis techniques. Principal Component Analysis (PCA) was chosen as a method of data exploration. The study was conducted on four plants controlled in Poland: Salvia divinorum, Mitragyna speciosa, Psychotria viridis and Calea zacatechichi. The compatibility of grouping features of selected species was compared in two variants: chemical and elemental composition. In a first variant, GC-MS chromatograms of extracts were analyzed and in the second, elements composition with the AAS and the ICP-MS techniques. The GC-MS method, based on the qualitative interpretation of results, allows for clear differentiation of samples with regard to their species affiliation. Even the plants belonging to the same family Rubiaceae, P. viridis and M. speciosa formed homogeneous and clearly separated clusters. Additionally, the cluster analysis was performed, as a method confirming sample grouping.

  18. Novos táxons de Hemilophini (Coleoptera, Cerambycidae da Região Neotropical New taxa of Hemilophini (Coleoptera, Cerambycidae from the Neotropical Region

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    Maria Helena M. Galileo


    Full Text Available Novos táxons descritos da Costa Rica: Erana cretaria sp. nov., Itumbiara denudata sp. nov., Hilaroleopsis coloratus sp. nov., Alampyris flavicollis sp. nov., Cotycuara viridis sp. nov., Adesmus stellatus sp. nov., A. pilatus sp. nov. (também do Panamá; do Panamá: Eulachnesia amoena sp. nov., Cotycuara crinita sp. nov.; da Venezuela: Abanycha fasciata sp. nov.; do Equador: Mariliana hovorei sp. nov., Adesmus ocellatus sp. nov.; do Peru: Susuanycha gen. nov., espécie-tipo, S. susua sp. nov., Malacoscylus elegantulus sp. nov., Adesmus guttatus sp. nov., A. calca sp. nov.; do Brasil (Minas Gerais: Sybaguasu cornutum sp. nov. Acrescenta-se chave para as espécies de Cotycuara.New taxa described from Costa Rica: Erana cretaria sp. nov., Itumbiara denudata sp. nov., Hilaroleopsis coloratus sp. nov., Alampyris flavicollis sp. nov., Cotycuara viridis sp. nov., Adesmus stellatus sp. nov., A. pilatus sp. nov. (also from Panama; from Panama: Eulachnesia amoena sp. nov., Cotycuara crinita sp. nov.; from Venezuela: Abanycha fasciata sp. nov.; from Ecuador: Mariliana hovorei sp. nov., Adesmus ocellatus sp. nov.; from Peru: Susuanycha gen. nov., type species, S. susua sp. nov., Malacoscylus elegantulus sp. nov., Adesmus guttatus sp. nov., A. calca sp. nov.; from Brazil (Minas Gerais: Sybaguasu cornutum sp. nov. A key to the species of Cotycuara is added.

  19. Ayahuasca: Pharmacology, neuroscience and therapeutic potential. (United States)

    Domínguez-Clavé, Elisabet; Soler, Joaquim; Elices, Matilde; Pascual, Juan C; Álvarez, Enrique; de la Fuente Revenga, Mario; Friedlander, Pablo; Feilding, Amanda; Riba, Jordi


    Ayahuasca is the Quechua name for a tea obtained from the vine Banisteriopsis caapi, and used for ritual purposes by the indigenous populations of the Amazon. The use of a variation of the tea that combines B. caapi with the leaves of the shrub Psychotria viridis has experienced unprecedented expansion worldwide for its psychotropic properties. This preparation contains the psychedelic 5-HT2A receptor agonist N,N-dimethyltryptamine (DMT) from P. viridis, plus β-carboline alkaloids with monoamine-oxidase-inhibiting properties from B. caapi. Acute administration induces a transient modified state of consciousness characterized by introspection, visions, enhanced emotions and recollection of personal memories. A growing body of evidence suggests that ayahuasca may be useful to treat substance use disorders, anxiety and depression. Here we review the pharmacology and neuroscience of ayahuasca, and the potential psychological mechanisms underlying its therapeutic potential. We discuss recent findings indicating that ayahuasca intake increases certain mindfulness facets related to acceptance and to the ability to take a detached view of one's own thoughts and emotions. Based on the available evidence, we conclude that ayahuasca shows promise as a therapeutic tool by enhancing self-acceptance and allowing safe exposure to emotional events. We postulate that ayahuasca could be of use in the treatment of impulse-related, personality and substance use disorders and also in the handling of trauma. More research is needed to assess the full potential of ayahuasca in the treatment of these disorders.

  20. cis-Active Ras G2-like sequence implicated in the heterotropic activation of the deoxyadenosine kinase of Lactobacillus acidophilus R-26. (United States)

    Guo, S; Ma, N; Ives, D H


    Deoxyadenosine kinase (dAK) forms a heterodimer with either deoxyguanosine kinase (dGK) or deoxycytidine kinase (dCK), and is heterotropically activated 3-5 times by dGuo or dCyd. Expressed alone, dAK is inactive and exhibits no response to dGuo or dCyd; activity and heterotropic response are fully restored upon reassociation with dGK or dCK. However, turnover of independently expressed dGK or dCK is nearly maximal, being further activated only 50-100% upon reassociation with dAK. In neither case is the heterotropic activation due to ligand-induced heterodimer formation. A proline/alanine substitution within a dAK segment homologous to loop G2 of Ras proteins yielded a heterodimer with dAK permanently cis-activated 2-fold, with a corresponding reduction in heterotropic activation by dGuo. A chimeric dAK, with 25% of its C terminus substituted by the homologous sequence from dGK, was inactive alone, and its characteristics were unchanged in the reconstituted heterodimer. Superimposing the Pro/Ala substitution on this chimera also reduced heterotropic activation by half. Cross-linking the dimer by 1,5-difluoro-2,4-dinitrobenzene was inhibited by ATP, dATP, dGTP, and dAdo, suggesting the proximity of the active site(s) to the interface. These data suggest that dAK depends on dGK or dCK in a manner resembling the reliance of Ras upon GTPase activating protein.

  1. IL-23 in Infections, Inflammation, Autoimmunity and Cancer: Possible Role in HIV-1 and AIDS


    Yannam, Govardhana Rao; Gutti, Tanuja; Poluektova, Larisa Y.


    The growing family of interleukin (IL)-12-like cytokines produced by activated macrophages and dendritic cells became the important players in the control of infections, development of inflammation, autoimmunity and cancer. However, the role of one of them—heterodimer IL-23, which consists of IL12p40 and the unique p19 subunit in HIV-1 infection pathogenesis and progression to AIDS, represent special interest. We overviewed findings of IL-23 involvement in control of peripheral bacterial path...

  2. A family of selfish minicircular chromosomes with jumbled chloroplast gene fragments from a dinoflagellate. (United States)

    Zhang, Z; Cavalier-Smith, T; Green, B R


    Chloroplast genes of several dinoflagellate species are located on unigenic DNA minicircular chromosomes. We have now completely sequenced five aberrant minicircular chromosomes from the dinoflagellate Heterocapsa triquetra. These probably nonfunctional DNA circles lack complete genes, with each being composed of several short fragments of two or three different chloroplast genes and a common conserved region with a tripartite 9G-9A-9G core like the putative replicon origin of functional single-gene circular chloroplast chromosomes. Their sequences imply that all five circles evolved by differential deletions and duplications from common ancestral circles bearing fragments of four genes: psbA, psbC, 16S rRNA, and 23S rRNA. It appears that recombination between separate unigenic chromosomes initially gave intermediate heterodimers, which were subsequently stabilized by deletions that included part or all of one putative replicon origin. We suggest that homologous recombination at the 9G-9A-9G core regions produced a psbA/psbC heterodimer which generated two distinct chimeric circles by differential deletions and duplications. A 23S/16S rRNA heterodimer more likely formed by illegitimate recombination between 16S and 23S rRNA genes. Homologous recombination between the 9G-9A-9G core regions of both heterodimers and additional differential deletions and duplications could then have yielded the other three circles. Near identity of the gene fragments and 9G-9A-9G cores, despite diverging adjacent regions, may be maintained by gene conversion. The conserved organization of the 9G-9A-9G cores alone favors the idea that they are replicon origins and suggests that they may enable the aberrant minicircles to parasitize the chloroplast's replication machinery as selfish circles.

  3. The structure of the GemC1 coiled coil and its interaction with the Geminin family of coiled-coil proteins

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    Caillat, Christophe; Fish, Alexander [The Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands); Pefani, Dafni-Eleftheria; Taraviras, Stavros; Lygerou, Zoi [University of Patras, 26505 Rio, Patras (Greece); Perrakis, Anastassis, E-mail: [The Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands)


    The GemC1 coiled-coil structure has subtle differences compared with its homologues Geminin and Idas. Co-expression experiments in cells and biophysical stability analysis of the Geminin-family coiled coils suggest that the GemC1 coiled coil alone is unstable. GemC1, together with Idas and Geminin, an important regulator of DNA-replication licensing and differentiation decisions, constitute a superfamily sharing a homologous central coiled-coil domain. To better understand this family of proteins, the crystal structure of a GemC1 coiled-coil domain variant engineered for better solubility was determined to 2.2 Å resolution. GemC1 shows a less typical coiled coil compared with the Geminin homodimer and the Geminin–Idas heterodimer structures. It is also shown that both in vitro and in cells GemC1 interacts with Geminin through its coiled-coil domain, forming a heterodimer that is more stable that the GemC1 homodimer. Comparative analysis of the thermal stability of all of the possible superfamily complexes, using circular dichroism to follow the unfolding of the entire helix of the coiled coil, or intrinsic tryptophan fluorescence of a unique conserved N-terminal tryptophan, shows that the unfolding of the coiled coil is likely to take place from the C-terminus towards the N-terminus. It is also shown that homodimers show a single-state unfolding, while heterodimers show a two-state unfolding, suggesting that the dimer first falls apart and the helices then unfold according to the stability of each protein. The findings argue that Geminin-family members form homodimers and heterodimers between them, and this ability is likely to be important for modulating their function in cycling and differentiating cells.

  4. Detailed Per-residue Energetic Analysis Explains the Driving Force for Microtubule Disassembly


    Ayoub, Ahmed T.; Mariusz Klobukowski; Tuszynski, Jack A


    Microtubules are long filamentous hollow cylinders whose surfaces form lattice structures of αβ-tubulin heterodimers. They perform multiple physiological roles in eukaryotic cells and are targets for therapeutic interventions. In our study, we carried out all-atom molecular dynamics simulations for arbitrarily long microtubules that have either GDP or GTP molecules in the E-site of β-tubulin. A detailed energy balance of the MM/GBSA inter-dimer interaction energy per residue contributing to t...

  5. Analysis of RXR/THR and RXR/PPARG2 heterodimerization by bioluminescence resonance energy transfer (BRET.

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    Miquel Mulero

    Full Text Available BACKGROUND: Nuclear receptors (NR regulate transcription of genes involved in many biological processes such as development, cell proliferation, differentiation and cell death. Amongst them, PPARG2 and THR control tissue glucose and lipid homeostasis which are deregulated in severe pathophysiological conditions such as metabolic syndromes. METHODOLOGY/PRINCIPAL FINDINGS: Here, we describe a real time BRET approach to monitor heterodimerization between RXR and PPARG2 or THR in vitro or in living cells. The presence of a specific DNA target was required to induce in vitro a BRET shift reflecting heterodimerization of RXR/PPARG2 or RXR/THR. As in electrophoretic mobility shift assay (EMSA, the stringency and specificity of the BRET shift assay depended upon assay condition optimization including MgCl2 concentration. For the nuclear receptors, we found by mutagenesis analysis that each heterodimer partner must harbor an intact DNA binding domain to induce BRET and heterodimerization on a DNA target. Moreover the interaction between the PPARG2 ligand binding domain and the RXR DNA binding domain stabilized the heterodimer on its DNA target. BRET microscopy in living cells highlighted the heterodimerization of RXR/PPARG2 within the nucleus clustered in discrete foci that may represent active target gene transcription regulation regions. BRET imaging also suggested that heterodimerization between RXR and PPARG2 required the DNA binding of PPARG2. CONCLUSIONS/SIGNIFICANCE: The BRET approach described here allowed us to study the dynamic interactions which exist between NR in vitro or in living cells and can provide important information on heterodimerization modes, affinity with a given RE and subcellular localization of the heterodimers. This method could be used to study real time changes of NR heterodimers occurring on DNA depending upon cell activation, chromatin state and help to define the mechanisms of ligands or drug action designed to target

  6. Heterodimerization of ORL1 and Opioid Receptors and Its Consequences for N-type Calcium Channel Regulation*


    Evans, Rhian M; You, Haitao; Hameed, Shahid; Altier, Christophe; Mezghrani, Alexandre; Bourinet, Emmanuel; Zamponi, Gerald W.


    We have investigated the heterodimerization of ORL1 receptors and classical members of the opioid receptor family. All three classes of opioid receptors could be co-immunoprecipitated with ORL1 receptors from both transfected tsA-201 cell lysate and rat dorsal root ganglia lysate, suggesting that these receptors can form heterodimers. Consistent with this hypothesis, in cells expressing either one of the opioid receptors together with ORL1, prolonged ORL1 receptor activation via nociceptin ap...

  7. The Role of Actin-Capping Protein and Src signalling in tissue growth and apoptosis during Drosophila wing development


    Jezowska, Barbara Zofia


    Dissertation presented to obtain the Ph.D degree in Developmental Biology The actin cytoskeleton controls numerous cellular processes, including cell morphology and polarity, endocytosis, intracellular trafficking, contractility and cell division. Actin filament growth, stability and disassembly are controlled by a plethora of actin-binding proteins. Among them Capping Protein is a highly conserved αβ heterodimer, which binds the barbed ends of actin filaments, inhibiting addit...

  8. Brief Note Low diversity of the major histocompatibility complex class II DRA gene in domestic goats (Capra hircus) in Southern China. (United States)

    Chen, L P; E, G X; Zhao, Y J; Na, R S; Zhao, Z Q; Zhang, J H; Ma, Y H; Sun, Y W; Zhong, T; Zhang, H P; Huang, Y F


    DRA encodes the alpha chain of the DR heterodimer, is closely linked to DRB and is considered almost monomorphic in major histocompatibility complex region. In this study, we identified the exon 2 of DRA to evaluate the immunogenetic diversity of Chinese south indigenous goat. Two single nucleotide polymorphisms in an untranslated region and one synonymous substitution in coding region were identified. These data suggest that high immunodiversity in native Chinese population.

  9. The LINK-A lncRNA Activates Normoxic HIF1α Signaling in Triple-negative Breast Cancer


    Lin, Aifu; Li, Chunlai; Xing, Zhen; Hu, Qingsong; Liang, Ke; Han, Leng; Wang, Cheng; Hawke, David H.; Wang, Shouyu; ZHANG, Yanyan; Wei, Yongkun; Ma, Guolin; Park, Peter K.; Zhou, Jianwei; Zhou, Yan


    Although long noncoding RNAs (lncRNAs) predominately reside in nuclear and exert their functions in many biological processes, their potential involvement in cytoplasmic signal transduction remains unexplored. Here, we identified a cytoplasmic lncRNA, Long-Intergenic Noncoding RNA for Kinase Activation (LINK-A), which mediates HB-EGF triggered, EGFR:GPNMB heterodimer-dependent HIF1α phosphorylation at Tyr565 and Ser797 by BRK and LRRK2 respectively. These events cause HIF1α stabilization, HIF...

  10. The Escherichia coli BolA Protein IbaG Forms a Histidine-Ligated [2Fe-2S]-Bridged Complex with Grx4. (United States)

    Dlouhy, Adrienne C; Li, Haoran; Albetel, Angela-Nadia; Zhang, Bo; Mapolelo, Daphne T; Randeniya, Sajini; Holland, Ashley A; Johnson, Michael K; Outten, Caryn E


    Two ubiquitous protein families have emerged as key players in iron metabolism, the CGFS-type monothiol glutaredoxins (Grxs) and the BolA proteins. Monothiol Grxs and BolA proteins form heterocomplexes that have been implicated in Fe-S cluster assembly and trafficking. The Escherichia coli genome encodes members of both of these proteins families, namely, the monothiol glutaredoxin Grx4 and two BolA family proteins, BolA and IbaG. Previous work has demonstrated that E. coli Grx4 and BolA interact as both apo and [2Fe-2S]-bridged heterodimers that are spectroscopically distinct from [2Fe-2S]-bridged Grx4 homodimers. However, the physical and functional interactions between Grx4 and IbaG are uncharacterized. Here we show that co-expression of Grx4 with IbaG yields a [2Fe-2S]-bridged Grx4-IbaG heterodimer. In vitro interaction studies indicate that IbaG binds the [2Fe-2S] Grx4 homodimer to form apo Grx4-IbaG heterodimer as well as the [2Fe-2S] Grx4-IbaG heterodimer, altering the cluster stability and coordination environment. Additionally, spectroscopic and mutagenesis studies provide evidence that IbaG ligates the Fe-S cluster via the conserved histidine that is present in all BolA proteins and by a second conserved histidine that is present in the H/C loop of two of the four classes of BolA proteins. These results suggest that IbaG may function in Fe-S cluster assembly and trafficking in E. coli as demonstrated for other BolA homologues that interact with monothiol Grxs.

  11. Interplay of CREB and ATF2 in Ionizing Radiation-Induced Neuroendocrine Differentiation of Prostate Cancer Cells (United States)


    cross-talk between Hh and androgen signaling in prostate cancer. Source of Funding: NCI RO1-CA111618; DOD W81XWH-06 377 WHAT CAN THE HAIR FOLLICLES ...demonstrated that targeting CREB signaling can increase IR-induced cell death. We also demonstrated that IR induces NED in xenograft nude mouse models and in...heterodimer to regulate gene transcription [21]. While some target genes can be activated by CREB and ATF2 equally or cooperatively [22-24

  12. Biological Activity of 4-Substituted Methoxybenzoyl-Aryl-Thiazole (SMART): An Active Microtubule Inhibitor



    Formation of microtubules is a dynamic process that involves polymerization and depolymerization of αβ-tubulin heterodimers. Drugs that enhance or inhibit tubulin polymerization can destroy this dynamic process, arresting cells in the G2/M phase of the cell cycle. Although drugs that target tubulin generally demonstrate cytotoxic potency in the sub-nanomolar range, resistance due to drug efflux is a common phenomenon among the antitubulin agents. We recently reported a class of 4-Substituted ...


    Lifescience Database Archive (English)

    Full Text Available B5 and ATHB6 exhibit identical DNA binding specificities; ATHB5 forms heterodimers with class I HDzip proteins; See also S000475; Homeodomein-leucine zipper; HDzip; ATHB5; class I; HDZip I; Arabidopsis thaliana CAATNATTG ... ...ATHB5ATCORE S000371 05-November-2005 (last modified) kehi Consensus binding sequenc...e for Arabidopsis (A.T.) class I HDzip (Homeodomein-leucine zipper) protein, ATHB5; ATHB5 protein forms dimers in solution; ATH

  14. Activated receptors for peroxisomic proliferators. Its role in the atherosclerosis, obesity and high blood pressure. Los receptores activados por proliferadores peroxisómicos. Su papel en la aterosclerosis, obesidad e hipertensión arterial.


    Yosvel Curbelo Pérez; Mikhail Benet Rodríguez


    The receptors activated by peroxisome proliferators are a family of factors of transcription that belong to the superfamily of the steroid receptors and include tree subtypes which are PPARá, PPAR©¬ and PPAR ã. These receptors join to direct hexameric repetitions in the form of heterodimers with the retinoid receptor. PPAR receptors regulate the expressions of a great variety of genes that codify the proteins that are implied in the lipid metabolism, the energetic homeostasis, the cellular di...

  15. Domain Specific Effects of Herstatin, an Alternative HER-2 (erbB-2) Product, on erbB Positive Breast Cancer (United States)


    53. Sambrook, J., Maniatis , T., and Fritsch, E. F. (1989) Molecular cloning : a laboratory manual, 2nd Ed., Cold Spring Harbor Laboratory, Cold Spring...of HER-2 is a common molecular abnormality in breast cancer, implicated in 20 - 30% of all cases(6). HER-2 is the preferred heterodimer partner of...its efficacy is limited to a subset of HER-2 overexpressing breast tumors, and its molecular mechanism is poorly understood. This points to the great

  16. Establishing the interaction between the CC chemokine ligand 5 and the receptors CCR1 and CCR5



    Chemokines are important mediators and regulators of leukocyte trafficking, therefore, they play a crucial role in the development of inflammatory diseases. CCL5 or RANTES (regulated upon activation, normal T cell expressed and secreted) is a chemokine of relevance to many diseases. Moreover, CCL5-induced monocyte adhesion to inflamed endothelium was shown to be improved in the presence of CXCL4 (Platelet Factor 4). Since this synergy could be attributed to heterodimer formation, the first se...

  17. 陕北7种杂草种子对石油污染的耐受性研究%Responses of Seed Germination of 7 Weed Plants to Petroleum Contamination

    Institute of Scientific and Technical Information of China (English)

    祁迎春; 王建; 王宏; 任绵绵; 山宝琴; 同延安


    为筛选可用于陕北油田区石油污染土壤修复的杂草植物,试验通过野外调查,选择当地石油污染严重的土壤上能较好生长的7种杂草植物为研究对象,以种子发芽作为生态指示,设置不同土壤石油质量浓度的培养试验,通过观测每天的发芽率和最终发芽时间,研究了杂草种子对石油污染的耐受性。结果表明,在土壤石油质量分数达到9 g/kg时各杂草种子发芽率开始受到抑制。石油污染胁迫下总体萌发能力排序为:狗尾草(Setaria viridis)>沙打旺(Astragalus adsurgens)>紫花苜蓿(Medicago sativa)>草木犀(Melilotus officinalis)>皱果苋(Amaranthus viridis)>灰灰菜(Chenopodium album)>黄花蒿(Artemisia annua)。其中狗尾草、紫花苜蓿、沙打旺和草木犀4种杂草植物在石油质量分数为9,17 g/kg土壤中发芽率都达到对照的70%以上,对石油污染胁迫具有较强的耐受性。在试验条件下(培养前蒸馏水浸种24 h),土壤石油并未对杂草种子发芽时间造成显著影响。%To screen plants for phytoremediation of petroleum- contaminated soils, four treatments with different levels of petroleum pollutants were designed and seed germination rate and germination time of 7 tested plant species were determined to investigate the germination adaptability of the tested plants in petroleum- contaminated soils. The results showed that these weed seeds were inhibited when the concentrations of petroleum pollution reached 9 g/kg. The germination adaptability of the tested plants was as follows:Setaria viridis>Astragalus adsurgens>Medicago sativa>Melilotus officinalis> Amaranthus viridis > Chenopodium album > Artemisia annua. The germination rate of Setaria viridis, Astragalus adsurgens, Medicago sativa and Melilotus officinalis could be above 70% when the concentration of petroleum pollution was 9 and 17 g/kg, and these plant species have a high tolerance of petroleum hydrocarbon

  18. Structural analyses at pseudo atomic resolution of Chikungunya virus and antibodies show mechanisms of neutralization. (United States)

    Sun, Siyang; Xiang, Ye; Akahata, Wataru; Holdaway, Heather; Pal, Pankaj; Zhang, Xinzheng; Diamond, Michael S; Nabel, Gary J; Rossmann, Michael G


    A 5.3 Å resolution, cryo-electron microscopy (cryoEM) map of Chikungunya virus-like particles (VLPs) has been interpreted using the previously published crystal structure of the Chikungunya E1-E2 glycoprotein heterodimer. The heterodimer structure was divided into domains to obtain a good fit to the cryoEM density. Differences in the T = 4 quasi-equivalent heterodimer components show their adaptation to different environments. The spikes on the icosahedral 3-fold axes and those in general positions are significantly different, possibly representing different phases during initial generation of fusogenic E1 trimers. CryoEM maps of neutralizing Fab fragments complexed with VLPs have been interpreted using the crystal structures of the Fab fragments and the VLP structure. Based on these analyses the CHK-152 antibody was shown to stabilize the viral surface, hindering the exposure of the fusion-loop, likely neutralizing infection by blocking fusion. The CHK-9, m10 and m242 antibodies surround the receptor-attachment site, probably inhibiting infection by blocking cell attachment. DOI:

  19. Structural Basis for Dimer Formation of Human Condensin Structural Maintenance of Chromosome Proteins and Its Implications for Single-stranded DNA Recognition. (United States)

    Uchiyama, Susumu; Kawahara, Kazuki; Hosokawa, Yuki; Fukakusa, Shunsuke; Oki, Hiroya; Nakamura, Shota; Kojima, Yukiko; Noda, Masanori; Takino, Rie; Miyahara, Yuya; Maruno, Takahiro; Kobayashi, Yuji; Ohkubo, Tadayasu; Fukui, Kiichi


    Eukaryotic structural maintenance of chromosome proteins (SMC) are major components of cohesin and condensins that regulate chromosome structure and dynamics during cell cycle. We here determine the crystal structure of human condensin SMC hinge heterodimer with ~30 residues of coiled coils. The structure, in conjunction with the hydrogen exchange mass spectrometry analyses, revealed the structural basis for the specific heterodimer formation of eukaryotic SMC and that the coiled coils from two different hinges protrude in the same direction, providing a unique binding surface conducive for binding to single-stranded DNA. The characteristic hydrogen exchange profiles of peptides constituted regions especially across the hinge-hinge dimerization interface, further suggesting the structural alterations upon single-stranded DNA binding and the presence of a half-opened state of hinge heterodimer. This structural change potentially relates to the DNA loading mechanism of SMC, in which the hinge domain functions as an entrance gate as previously proposed for cohesin. Our results, however, indicated that this is not the case for condensins based on the fact that the coiled coils are still interacting with each other, even when DNA binding induces structural changes in the hinge region, suggesting the functional differences of SMC hinge domain between condensins and cohesin in DNA recognition.

  20. Insights into the interaction of discodermolide and docetaxel with tubulin. Mapping the binding sites of microtubule-stabilizing agents by using an integrated NMR and computational approach. (United States)

    Canales, Angeles; Rodríguez-Salarichs, Javier; Trigili, Chiara; Nieto, Lidia; Coderch, Claire; Andreu, José Manuel; Paterson, Ian; Jiménez-Barbero, Jesús; Díaz, J Fernando


    The binding interactions of two antitumor agents that target the paclitaxel site, docetaxel and discodermolide, to unassembled α/β-tubulin heterodimers and microtubules have been studied using biochemical and NMR techniques. The use of discodermolide as a water-soluble paclitaxel biomimetic and extensive NMR experiments allowed the detection of binding of microtubule-stabilizing agents to unassembled tubulin α/β-heterodimers. The bioactive 3D structures of docetaxel and discodermolide bound to α/β-heterodimers were elucidated and compared to those bound to microtubules, where subtle changes in the conformations of docetaxel in its different bound states were evident. Moreover, the combination of experimental TR-NOE and STD NMR data with CORCEMA-ST calculations indicate that docetaxel and discodermolide target an additional binding site at the pore of the microtubules, which is different from the internal binding site at the lumen previously determined by electron crystallography. Binding to this pore site can then be considered as the first ligand-protein recognition event that takes place in advance of the drug internalization process and interaction with the lumen of the microtubules.

  1. DNA and IκBα both induce long range conformational changes in NFκB. (United States)

    Ramsey, Kristen M; Dembinski, Holly E; Chen, Wei; Ricci, Clarisse G; Komives, Elizabeth A


    We recently discovered that IκBα enhances the rate of release of NFκB from DNA target sites in a process we have termed molecular stripping. Coarse-grained molecular dynamics simulations of the stripping pathway revealed two mechanisms for the enhanced release rate; the negatively charged PEST region of IκBα electrostatically repels the DNA, and binding of IκBα appears to twist the NFκB heterodimer so that DNA can no longer bind. Here we report amide hydrogen/deuterium exchange data that reveals long-range allosteric changes in the NFκB (RelA-p50) heterodimer induced by DNA or IκBα binding. The data suggest that the two immunoglobulin-like subdomains of each Rel-homology region, which are connected by a flexible linker in the heterodimer, communicate in such a way that when DNA binds to the N-terminal DNA binding domains, the nuclear localization signal becomes more highly exchanging. Conversely, when IκBα binds to the dimerization domains, amide exchange throughout the DNA binding domains is decreased as if the entire domain is becoming globally stabilized. The results help understand how the subtle mechanism of molecular stripping actually occurs.

  2. A heterodimeric complex of the LRR proteins LRIM1 and APL1C regulates complement-like immunity in Anopheles gambiae

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Richard H.G.; Steinert, Stefanie; Chelliah, Yogarany; Volohonsky, Gloria; Levashina, Elena A.; Deisenhofer, Johann (CNRS-UMR); (UTSMC)


    The leucine-rich repeat (LRR) proteins LRIM1 and APL1C control the function of the complement-like protein TEP1 in Anopheles mosquitoes. The molecular structure of LRIM1 and APL1C and the basis of their interaction with TEP1 represent a new type of innate immune complex. The LRIM1/APL1C complex specifically binds and solubilizes a cleaved form of TEP1 without an intact thioester bond. The LRIM1 and APL1C LRR domains have a large radius of curvature, glycosylated concave face, and a novel C-terminal capping motif. The LRIM1/APL1C complex is a heterodimer with a single intermolecular disulfide bond. The structure of the LRIM1/APL1C heterodimer reveals an interface between the two LRR domains and an extensive C-terminal coiled-coil domain. We propose that a cleaved form of TEP1 may act as a convertase for activation of other TEP1 molecules and that the LRIM1/APL1C heterodimer regulates formation of this TEP1 convertase.

  3. The integrins. (United States)

    Takada, Yoshikazu; Ye, Xiaojing; Simon, Scott


    The integrins are a superfamily of cell adhesion receptors that bind to extracellular matrix ligands, cell-surface ligands, and soluble ligands. They are transmembrane alphabeta heterodimers and at least 18 alpha and eight beta subunits are known in humans, generating 24 heterodimers. Members of this family have been found in mammals, chicken and zebrafish, as well as lower eukaryotes, including sponges, the nematode Caenorhabditis elegans (two alpha and one beta subunits, generating two integrins) and the fruitfly Drosophila melanogaster (five alpha and one beta, generating five integrins). The alpha and beta subunits have distinct domain structures, with extracellular domains from each subunit contributing to the ligand-binding site of the heterodimer. The sequence arginine-glycine-aspartic acid (RGD) was identified as a general integrin-binding motif, but individual integrins are also specific for particular protein ligands. Immunologically important integrin ligands are the intercellular adhesion molecules (ICAMs), immunoglobulin superfamily members present on inflamed endothelium and antigen-presenting cells. On ligand binding, integrins transduce signals into the cell interior; they can also receive intracellular signals that regulate their ligand-binding affinity. Here we provide a brief overview that concentrates mostly on the organization, structure and function of mammalian integrins, which have been more extensively studied than integrins in other organisms.

  4. Acyl-biotinyl exchange chemistry and mass spectrometry-based analysis of palmitoylation sites of in vitro palmitoylated rat brain tubulin. (United States)

    Zhao, Zhiqiang; Hou, Junjie; Xie, Zhensheng; Deng, Jianwei; Wang, Xiaoming; Chen, Danfang; Yang, Fuquan; Gong, Weimin


    Research has shown that the palmitoyl group of α-tubulin mediates the hydrophobic interaction between microtubules and intracellular membranes and that palmitoylated tubulin plays a role in signal transduction. There are 20 cysteine residues per α/β tubulin heterodimer. C376 of α-tubulin was reported to be predominantly palmitoylated and C20, C213 and C305 of α-tubulin were palmitoylated at lower levels. The previous method used for the analysis of the palmitoylation sites on α-tubulin was based on ³H-labeling, enzymolysis, purification and sequencing. This approach, although efficient, is laborious. Mass spectrometry (MS), especially tandem MS, has been shown to be a successful method for identification of various post-translational modifications of proteins. We report here a convenient MS-based method to comprehensively analyze the palmitoylation sites of the α/β tubulin heterodimer. Acyl-biotinyl exchange chemistry and streptavidin agarose affinity purification were applied to enrich palmitoylated peptides from tubulin. After nano-LC-MS/MS analysis, database searching and manual analysis of the spectra revealed that 11 cysteine residues of the α/β tubulin heterodimer were palmitoylated.

  5. In vitro refolding of heterodimeric CapZ expressed in E. coli as inclusion body protein. (United States)

    Remmert, K; Vullhorst, D; Hinssen, H


    CapZ is a heterodimeric Ca(2+)-independent actin binding protein which plays an important role in organizing the actin filament lattice of cross-striated muscle cells. It caps the barbed end of actin filaments and promotes nucleation of actin polymerization, thereby regulating actin filament length. Here we report the expression of the two muscle-specific isoforms alpha2 and beta1, from chicken in Escherichia coli as individual subunits using the pQE60 expression vector and the subsequent renaturation of the functional CapZ heterodimer from inclusion bodies. Optimal renaturation conditions were obtained both by simultaneous refolding of urea-solubilized subunits and by rapid dilution into a buffer containing 20% glycerol, 5 mM EGTA, 2 mM DTT, 1 mM PMSF, and 100 mM Tris, pH 7.4. The refolding mixture was incubated for 24 h at 15 degrees C and the protein was concentrated by ultrafiltration. Biochemical characterization of the recombinant heterodimer revealed actin binding activities indistinguishable from those of native CapZ as purified from chicken skeletal muscle. Using the same protocol, we were able to refold the beta1, but not the alpha2 isoform as a single polypeptide, indicating a role for beta1 as a molecular template for the folding of alpha2. The reported recombinant approach leads to high yields of active heterodimer and allows the renaturation and characterization of the beta subunit.

  6. Distinct complexes of yeast Snx4 family SNX-BARs mediate retrograde trafficking of Snc1 and Atg27. (United States)

    Ma, Mengxiao; Burd, Christopher G; Chi, Richard J


    The yeast SNX4 sub-family of sorting nexin containing a Bin-Amphiphysin-Rvs domain (SNX-BAR) proteins, Snx4/Atg24, Snx41 and Atg20/Snx42, are required for endocytic recycling and selective autophagy. Here, we show that Snx4 forms 2 functionally distinct heterodimers: Snx4-Atg20 and Snx4-Snx41. Each heterodimer coats an endosome-derived tubule that mediates retrograde sorting of distinct cargo; the v-SNARE, Snc1, is a cargo of the Snx4-Atg20 pathway, and Snx4-Snx41 mediates retrograde sorting of Atg27, an integral membrane protein implicated in selective autophagy. Live cell imaging of individual endosomes shows that Snx4 and the Vps5-Vps17 retromer SNX-BAR heterodimer operate concurrently on a maturing endosome. Consistent with this, the yeast dynamin family protein, Vps1, which was previously shown to promote fission of retromer-coated tubules, promotes fission of Snx4-Atg20 coated tubules. The results indicate that the yeast SNX-BAR proteins coat 3 distinct types of endosome-derived carriers that mediate endosome-to-Golgi retrograde trafficking.

  7. Genetic and molecular basis of individual differences in human umami taste perception.

    Directory of Open Access Journals (Sweden)

    Noriatsu Shigemura

    Full Text Available Umami taste (corresponds to savory in English is elicited by L-glutamate, typically as its Na salt (monosodium glutamate: MSG, and is one of five basic taste qualities that plays a key role in intake of amino acids. A particular property of umami is the synergistic potentiation of glutamate by purine nucleotide monophosphates (IMP, GMP. A heterodimer of a G protein coupled receptor, TAS1R1 and TAS1R3, is proposed to function as its receptor. However, little is known about genetic variation of TAS1R1 and TAS1R3 and its potential links with individual differences in umami sensitivity. Here we investigated the association between recognition thresholds for umami substances and genetic variations in human TAS1R1 and TAS1R3, and the functions of TAS1R1/TAS1R3 variants using a heterologous expression system. Our study demonstrated that the TAS1R1-372T creates a more sensitive umami receptor than -372A, while TAS1R3-757C creates a less sensitive one than -757R for MSG and MSG plus IMP, and showed a strong correlation between the recognition thresholds and in vitro dose-response relationships. These results in human studies support the propositions that a TAS1R1/TAS1R3 heterodimer acts as an umami receptor, and that genetic variation in this heterodimer directly affects umami taste sensitivity.

  8. Hetero subunit interaction and RNA recognition of yeast tRNA (m7G46) methyltransferase synthesized in a wheat germ cell-free translation system. (United States)

    Muneyoshi, Yuki; Matsumoto, Keisuke; Tomikawa, Chie; Toyooka, Takashi; Ochi, Anna; Masaoka, Takashi; Endo, Yaeta; Hori, Hiroyuki


    Yeast tRNA (m(7)G46) methyltransferase contains two protein subunits (Trm8 and Trm82). The enzyme catalyzes a methyl-transfer from S-adenosyl-L-methionine to the N(7) atom of guanine at position 46 in tRNA. We deviced synthesis of active Trm8-Trm82 heterodimer in a wheat germ cell-free translation system. When Trm8 or Trm82 mRNA were used for a synthesis, Trm8 or Trm82 protein could be synthesized. Upon mixing the synthesized Trm8 and Trm82 proteins, no active Trm8-Trm82 heterodimer was produced. Active Trm8-Trm82 heterodimer was only synthesized under conditions, in which both Trm8 and Trm82 mRNAs were co-translated. To address the RNA recognition mechanism of the Trm8-Trm82 complex, we investigated methyl acceptance activities of eight truncated yeast tRNA(Phe) transcripts. In this meeting, we demonstrate that yeast Trm8-Trm82 has stricter recognition requirements for the tRNA molecule as compared to the bacterial enzyme, TrmB.

  9. Platelet-derived growth factor receptors form complexes with neuropilin-1 during megakaryocytic differentiation of thrombopoietin-dependent UT-7/TPO cells. (United States)

    Ohsaka, Akimichi; Hirota-Komatsu, Satoko; Araki, Marito; Komatsu, Norio


    Neuropilin-1 (NRP-1) is involved in angiogenesis, but the role of NRP-1 in megakaryocytopoiesis is not yet fully understood. In this study, we investigated whether thrombopoietin (TPO) regulates the expression of platelet-derived growth factor (PDGF) and its receptors (PDGFRs) on TPO-dependent UT-7/TPO cells and whether PDGFRs and NRP-1 on UT-7/TPO cells form complexes during megakaryocytic differentiation. When UT-7/TPO cells were starved of TPO for 24 h and then stimulated with 5 ng/ml TPO, the expression of PDGF-B, PDGFRα, and PDGFRβ were significantly up-regulated after the addition of TPO. TPO also induced tyrosine phosphorylation of PDGFRα but not PDGFRβ, and promoted the formation of PDGFRαβ heterodimer complexes. Furthermore, megakaryocytic differentiation of UT-7/TPO cells on treatment with phorbol myristate acetate (PMA) was accompanied by a marked up-regulation of PDGFRβ and NRP-1 protein expression, complex formation between PDGFRs and NRP-1, PDGFRαβ heterodimer complexes, and an increase in PDGF-BB-binding activity. Immunocytochemistry confirmed complex formation between PDGFRs and NRP-1 and PDGFRαβ heterodimer complexes in PMA-differentiated UT-7/TPO cells. Our observations suggest that NRP-1 is involved in megakaryocytopoiesis through complex formation with PDGFRs, and that NRP-1-PDGFR-complexes may contribute to effective cellular functions mediated by TPO and PDGF in megakaryocytic cells.

  10. Dimerization of two novel apoptosis-inducing proteins and its function in regulating cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    刘青珍; 甘淼; 齐义鹏; 李凌云; 齐兵


    Asy (apoptosis/saibousi Yutsudo) is a novel apoptosis-inducing gene found in 1999 by Yutsudo group in Japan. In 2000, Qi Bing et al. cloned another novel gene, named hap (homologue of ASY protein), which encoded the ASY interact ing protein, from human lung cell line (WI-38) cDNA library by using yeast two-h ybrid system. It has been proved that ASY formed homodimer in yeast and human ce ll line, ASY and HAP formed heterodimer in yeast cells, and both induced cell ap optosis in human tumor cell lines Sao2 and CGL4. This paper showed that HAP coul d form homodimer in yeast cells by yeast two-hybrid system; HAP and ASY could pr oduce heterodimer in human cell line by cross-immunoprecipitation test; by using apoptosis-testing technologies such as AnnexinV, TUNEL, DNA ladder and Flow Cyt ometry, the cell apoptosis in human normal or tumor cell lines transfected with hap or asy individually or cotransfected by the both was qualified or quantified . It was firstly demonstrated that ASY or HAP induced cell apoptosis not only in human tumor cell lines, but also in human normal cell lines. Moreover, we prove d that the heterodimer between ASY and HAP decreased apoptosis-inducing activity from the homodimer of ASY or HAP. It revealed that by choosing to form heterodi mer or homodimer between ASY and / or HAP is an important mechanism of regulatin g apoptosis in human cell lines.

  11. Controle de plantas daninhas na cultura do milho (Zea mays L. por meio de herbicidas Weed control in maize (Zea mays L. with herbicides

    Directory of Open Access Journals (Sweden)

    C. A. L. dos Santos


    Full Text Available Com o objetivo de se verificar a ação do butylate, aplicado isoladamente e em mistura com atrazine, no controle de plantas daninhas da cultura do milho, foi instalado um experimento de campo em solo fino areno-argiloso. Foram utilizados os seguintes tratamentos: butylate a 2,80; 3,60 e 4,32 kg/ha (p.p.i.; butylate + atrazine a 3,24 + 0,80; 3,24 + 1,20 e 3,60 + 0,96 kg/ha (p.p.i.; atrazine a 3,00 kg/ha e atrazine + metolachlor a 1,40 + 2,10 kg/ha, ambos aplicados em pré-emergência e empregados como herbicidas padrão para a cultura. As plantas daninhas encontradas foram: tiririca - Cyperus rotundus L., carurú comum - .:maranthus viridis L., capim de colchão - Digitaria sanguinalis (L. Scop. e capim pé-de-galinha Eleusine indica (L. Gaertn. Butylate nas três doses apresentou-se bem contra C. rotundus e E. indica; nas doses de 3,60 e 4,32 kg foram obtidos bons resultados sobre D. sanguinalis. Butylate + atrazine controlou, nas três doses, todas as espécies incidentes, o mesmo ocorrendo com a mistura atrazine + metolachlor. Atrazine foi mais eficiente para A. viridis e E. indica. Nas condições em que foi conduzido o experimento nenhum dos herbicidas foi prejudicial para a cultura.Butylate at 2.80; 3.60 and 4.32 kg/ha and butylate + atrazine at. 3.24 + 0.80; 3.24 + 1.20 and 3.60 + 0.96 kg, were applied in preplant incorporated; atrazine at 3.00 kg and atrazine + metolachlor at 1.40 + 2.10 kg were applied in preemergence on corn. The weeds were represented by Cyperus rotundus L., Amaranthus viridis L., Digitaria sanguinalis (L. Scop. and Eleusine indica (L. Gaertn. Butylate + atrazine, in all rates, atrazine + metolachlor and atrazine gave good control of the weeds in general. Butylate, in the three rates, controlled C. rotundus and E. indica; at 3.60 and 4.32 kg/ha controlled well D. sanguinalis. The herbicides did not cause injuries to the crop.

  12. 贵阳市3种野生叶菜的部分功能性成分及其理化特性研究%Analysis on partial functional components and physicochemical characters of 3 species of wild leaf vegetables in Guiyang

    Institute of Scientific and Technical Information of China (English)

    黄凯丰; 彭慧蓉; 郭肖; 欧腾; 宋毓雪


    以产自贵州地区的繁缕、灰灰菜和野苋菜野生蔬菜为试验材料,测定了其部分功能性成分及其理化特性.结果表明:不同野生蔬菜间功能性成分的含量存在差异,灰灰菜中的蔗糖、蛋白质及膳食纤维含量较高,繁缕中的淀粉含量较高,野苋菜中黄酮含量较高;野苋菜的持水率和膨胀力显著高于灰灰菜和繁缕;3份野生蔬菜对不饱和脂肪的吸附能力总体在2.00 g/g左右,对饱和脂肪的吸附能力以灰灰菜最低;当3份野生蔬菜材料用量为0.1g时,其对胆固醇的吸附能力最大,野生蔬菜材料间差异不显著.%Stellaria media, Chenopodium album and Amaranthus viridis, 3 wild vegetables from Guizhou Province, were used as test materials, and their partial functional components and physico-chemical properties were studied. The results showed that the contents of functional components were different in different wild vegetables. The sucrose, protein and dietary fiber contents of C. Album were the highest,the starch content of S. Media was the highest,and the flavone content of A. Viridis was the highest. The water holding capacity and expansion capacity of A. Viridis were significantly higher than those of the other two vegetables. The 3 wild vegetables' capacity of adsorbing unsaturat-ed fat was about 2.00 g/g,and C. Album's capacity of adsorbing saturated fat was the lowest. When the amount of the 3 wild vegetable materials used was 0. 1 g, their cholesterol-adsorbing capacities were the greatest,and there were no significant differences among them.

  13. Dynamics of microcystins-LR and -RR in the phytoplanktivorous silver carp in a sub-chronic toxicity experiment

    Energy Technology Data Exchange (ETDEWEB)

    Xie Liqiang; Xie Ping; Ozawa, Kazuhiko; Honma, Takamitsu; Yokoyama, Atsushi; Park, Ho-Dong


    A sub-chronic toxicity experiment was conducted to examine tissue distribution and depuration of two microcystins (microcystin-LR and microcystin -RR) in the phytoplanktivorous filter-feeding silver carp during a course of 80 days. Two large tanks (A, B) were used, and in Tank A, the fish were fed naturally with fresh Microcystis viridis cells (collected from a eutrophic pond) throughout the experiment, while in Tank B, the food of the fish were M. viridis cells for the first 40 days and then changed to artificial carp feed. High Performance Liquid Chromatography (HPLC) was used to measure MC-LR and MC-RR in the M. viridis cells, the seston, and the intestine, blood, liver and muscle tissue of silver carp at an interval of 20 days. MC-RR and MC-LR in the collected Microcystis cells varied between 268-580 and 110-292 {mu}g g{sup -1} DW, respectively. In Tank A, MC-RR and MC-LR varied between 41.5-99.5 and 6.9-15.8 {mu}g g{sup -1} DW in the seston, respectively. The maximum MC-RR in the blood, liver and muscle of the fish was 49.7, 17.8 and 1.77 {mu}g g{sup -1} DW, respectively. No MC-LR was detectable in the muscle and blood samples of the silver carp in spite of the abundant presence of this toxin in the intestines (for the liver, there was only one case when a relatively minor quantity was detected). These findings contrast with previous experimental results on rainbow trout. Perhaps silver carp has a mechanism to degrade MC-LR actively and to inhibit MC-LR transportation across the intestines. The depuration of MC-RR concentrations occurred slowly than uptakes in blood, liver and muscle, and the depuration rate was in the order of blood>liver>muscle. The grazing ability of silver carp on toxic cyanobacteria suggests an applicability of using phytoplanktivorous fish to counteract cyanotoxin contamination in eutrophic waters. - Silver carp are tolerant of cyanobacterial toxins, and might be used to control toxic algal blooms in highly eutrophic lakes.

  14. Molecular cloning and characterization of cDNAs encoding metalloproteinases from snake venom glands. (United States)

    Jia, Ying; Pérez, John C


    Snake venom metalloproteinases (SVMPs) are a superfamily of zinc-dependent proteases and participate in a number of important biological, physiological and pathophysiological processes. In this work, we simultaneously amplified nine cDNAs encoding different classes of metalloproteinases from glands of four different snake species (Agkistrodon contortrix laticinctus, Crotalus atrox, Crotalus viridis viridis and Agkistrodon piscivorus leucostoma) by RT-PCR with a pair of primers. Among the encoded metalloproteinases, two enzymes (AclVMP-I and AplVMP-I), three enzymes (CaVMP-II, CvvVMP-II and AplVMP-II) and four enzymes (AclVMP-III, CaVMP-III, CvvVMP-III and AplVMP-III) with the characteristic motif (HEXXHXXGXXH) of metalloproteinase belong to type P-I, P-II and P-III enzymes, respectively. Disintegrin domains of CaVMP-II and CvvVMP-II from two Crotatus snakes contain RGD-motif whereas AplVMP-II from Agkistrodon snake has KGD-motif. Instead of R/KGD-motif within disintegrin domain of SVMP-II enzyme, CaVMP-III, CvvVMP-III and AplVMP-III enzymes contain SECD-motif, while AclVMP-III has DDCD-motif in their corresponding position of disintegrin-like domains. There are 12 Cys amino acids in cysterin-rich domains of each P-III enzyme. Moreover, a disintegrin precursor (AplDis) with RGD-motif also simultaneously amplified from the glands of A.p. leucostoma while amplifying AplVMP-II and AplVMP-III, which indicated that different types of SVMPs and related genes are present in a single species of snake and share a consensus sequence at the 3' and 5' untranslated regions. RT-PCR result also showed that P-III is highly expressed in Crotalus snakes than in Agkistrodon snakes. Aligning the deduced amino acid sequence of these enzymes with other SVMPs from GenBank database indicated that this is the first report on the isolation of cDNAs encoding P-II and P-III enzymes from C.v. viridis and A.p. leucostoma snakes. The availability of these SVMP sequences directly facilitated

  15. 微囊藻经滇池湿地处理前后在水体中的生长状况研究%Growth Status of the Microcystis in Water before and after Being Treated by Wetlands of Lake Dianchi

    Institute of Scientific and Technical Information of China (English)

    沈放; 路斌; 仝向荣; 杨黎江


    通过对湿地水体水样中惠氏微囊藻、铜绿微囊藻和绿色微囊藻的培养,检测经湿地净化后水体和湿地外周水体中微囊藻数量变化.比较得知,经湿地净化水样中的蓝藻细胞总数的上升趋势明显低于湿地外周水样.3种微囊藻的繁殖速度,在湿地外周水样中为:铜绿微囊藻〉〉惠氏微囊藻〉绿色微囊藻,铜绿微囊藻为优势种群;在经湿地净化水样中为:惠氏微囊藻≈铜绿微囊藻〉绿色微囊藻,3种微囊藻的比例与培养前相同,且优势藻群并非微囊藻类.结果表明,湿地能有效改变微囊藻的繁殖速率和水体中藻类的优势种群,明显抑制水体中的蓝藻数量,达到净化水质的目的.%After cultivating Microcystis wesenbergii,Microcystis viridis and Microcystis aeruginosa in the water samples collected from the peripheral and internal wetlands of Lake Dianchi, the changes in the number of Microcystis were detected. From the data, the up- ward trend of the total number of Cyanobacteria cells in the water samples of the internal wetland was significantly lower than the peripheral water wetlands. In the water samples from the peripheral wetland, three species of Microcystis reproduction speed was Microcystis aeruginosa 〉〉 Microcystis wesenbergii 〉 Microcystis viridis, and Microcystis aeruginosa was the dominant algae. In the water samples of the internal wetland, the reproduction rate of Microcystis was as followed:Microcystis aeruginosa ≈ Microcystis wesenbergii 〉 Microcystis viridis. Three kinds of Microcystis had the same proportion compared with the sample before being cultivated, and Microcystis was not the dominant algae. The results demonstrated that wetlands could change the reproduction rate of Microcystis effectively and the dominant algae populations, inhabit the number of Cyanobacteria in water significantly, then could reach the purpose of water purification.

  16. Genetic structure and origin of a tetraploid toad species Bufo danatensis Pisanetz, 1978 (Amphibia, Bufonidae) from central Asia: Description of biochemical polymorphism and comparison of heterozygosity levels in diploid and tetraploid species

    Energy Technology Data Exchange (ETDEWEB)

    Mezhzherin, S.V.; Pisanets, E.M. [Schmalhausen Institute of Zoology, Kiev (Ukraine)


    Comparison of individual variation at 24 biochemical loci in members of the species complex of Palearctic green toads showed that the heterozygosity of the tetraploid species Bufo danatensis (H{sub obs} = 0.45) was significantly higher than that of the diploid species B. viridis, B. sp., and B. raddei (H{sub obs} = 0.009 - 0.103). Such difference can be explained only by a hybrid origin of the tetraploid species. Individual electrophoretic variability of the polyploid toad species is associated with an allelic variation that is manifested in constantly heterozygous spectra as the gene dosage effect. At the population level, this phenomenon found in Pamir toads is caused by irregular meiosis in founders of the population or by directional changes in gene regulation. Genotypic distributions in zones of contact of the diploid and tetraploid taxons demonstrate the possibility of restricted introgressive hybridization.

  17. Structure of capsule around acanthocephalan Corynosoma strumosum from uncommon paratenic hosts-lizards of two species. (United States)

    Skorobrechova, Ekaterina M; Nikishin, Vladimir P; Lisitsyna, Olga I


    Micromorphology and ultrastructure of capsule forming around acanthocephalan Corynosoma strumosum in uncommon paratenic hosts-lizards Lacerta agilis and Lacerta viridis-have been studied. Experimental infestation of the lizards by acanthocephalans obtained from naturally infested sea fishes showed that only small amount of parasites occurred in the intestine of the host was able to migrate into body cavity and to be encapsulated. Micromorphology of capsules of different ages from different species of lizards and micromorphology and ultrastructure of capsules at the age of 1.5 and 10 days appeared to be similar. In the capsule's structure cells of inflammatory rank were prevailing: mononuclear and multinuclear macrophages, eosinophils, and basophils. Fibroblasts were not numerous and were located only in the outer part of a capsule; exocellular collagen fibers were absent. Inflammatory character of capsule confirms the idea that lizards are unsuitable paratenic hosts for corynosomes.

  18. The effect of storage of 2 varieties of golden algaes at different temperatures%温度对2种饵料金藻保存效果的影响

    Institute of Scientific and Technical Information of China (English)

    朱葆华; 潘克厚; 林黎明


    研究了在室温25℃±2℃,4, -5 ,-22℃下绿色巴夫藻(Pavlova viridis)和球等鞭金藻(Isochrysis galbana)的保存效果,通过测定其存活率以及主要脂肪酸的变化情况筛选出了2种金藻的适宜保存温度.结果表明,绿色巴夫藻短期内(30~45 d)在-5℃下保存效果最好,较长期(45 d以上)保存则应在-22℃,而球等鞭金藻则在-22℃下保存效果最好.

  19. Byssus thread: a novel support material for urease immobilization. (United States)

    Mishra, Neelam; Pithawala, Kespi; Bahadur, Anita


    Byssus threads are tough biopolymer produced by mussels (Mytilus viridis) to attach themselves to rocks. These were collected from mussels in their natural habitat (N) and from animals maintained in laboratory condition (L) as a novel support. Byssus thread surfaces were characterized by SEM analysis, chemically modified and used for adsorption of urease. The efficiency of the immobilization was calculated by examining the relative enzyme activity of free and the immobilized urease. The pH stabilities of immobilized urease were higher (0.5 unit) than free enzyme. Immobilized enzymes on byssus (both N and L) when stored at 6 °C retained 50% of its activity after 30 days, but they were more stable in dry condition. The optimum temperature of immobilized enzymes was found to increase (25 °C). A Michaelis-Menten constant (K (m)) value for immobilized urease was also elevated (2.08 mol).

  20. The orientation of the primary donor in bacterial photosynthesis. (United States)

    Frank, H A; Friesner, R; Nairn, J A; Dismukes, G C; Sauer, K


    The triplet state EPR spectra of magnetically aligned whole cells of Rhodopseudomonas viridis and Rhodopseudomonas palustris display a marked dependence on the orientation of the static EPR field with respect to the alignment field direction. This observation implies that the primary donor species on which the triplets are localized are ordered within the membranes. We have developed a theoretical model for the system to enable calculation of the orientation of the magnetic axes of the primary donor species with respect to the membranes in which they reside. The triplet state spectra are generated by an ensemble of partially ordered magnetic systems and a computer simulation of the experimental results. The triplet orientation is very similar for the two organisms studied, where one axis lies predominantly in the plane of the membrane and the other two axes have approximately equal projections onto the normal to the membrane.