Sample records for abundant oligonucleotides common

  1. Cross-protective effect of antisense oligonucleotide developed against the common 3' NCR of influenza A virus genome. (United States)

    Kumar, Prashant; Kumar, Binod; Rajput, Roopali; Saxena, Latika; Banerjea, Akhil C; Khanna, Madhu


    The influenza A virus (IAV) has eight segmented single-stranded RNA genome containing a common and evolutionarily conserved non-coding region (NCRs) at 5' and 3' ends that are important for the virus replication. In this study, we designed an antisense oligonucleotide against the 3' NCR of vital segments of the IAV genome to inhibit its replication. The results demonstrated that the co-transfection of Madine Darby Canine Kidney (MDCK) cells with the antisense oligonucleotide and the plasmids encoding the viral genes led to the down-regulation of the viral gene expression. The designed antisense molecules reduced the cytopathic effect caused by A/PR/8/34 (H1N1), A/Udorn/307/72 (H3N2), and A/New Caledonia/20/99 (H1N1) strains of IAV for almost 48 h. Furthermore, the intra-venous delivery of this oligonucleotide significantly reduced the viral titers in the lungs of infected mice and protected the mice from lethal effects of all the strains of influenza virus. The study demonstrated that the antisense oligonucleotide designed against the NCR region inhibits the expression of the viral genome. The decrease of the cytopathic effect in the MDCK cells and increase in survival of mice confirmed the reduction of virus multiplication and pathogenesis in the presence of antisense oligonucleotide. Thus, we demonstrate that a single antisense oligonucleotide is capable of providing protection against more than one strains of the IAV.

  2. Numerical Response of the Common Buzzard Buteo Buteo to The Changes In Abundance Of Small Mammals

    Directory of Open Access Journals (Sweden)

    Tóth László


    Full Text Available I investigated the numerical response of the Common Buzzard to variations in density of small mammals. The study was carried out at the Hortobágy region in 2000-2001. During nest visiting periods clutch size, number of hatched and fledged young were recorded. Population of small mammals were also monitored by live-trapping. Effect of weather on the survival of overwintering rodents was also investigated. There was significant difference in clutch size between 2000 and 2001 (means 2.3 and 3.1. It can be explained by the remarkable differences in abundance of small mammal populations between the two years. The density of rodents was very low (9 specimen/ha in 2000. During 2001 the amount of small mammals has increased more than eightfold (76 specimen/ha. In February and March, 2000 there were 4 short mild periods alternating with 4 freezing periods, when distribution of significant precipitation (6-8 mm rainfall in each coincided with the mild periods. Thus the overwintering population almost extincted from the area because the tunnel complexes of voles are repeatedly flooded and huge part of the animals died, resulting very low density during the breeding season. In 2001 there was no such alternating periods, mild weather started 3 weeks earlier, thus voles overwintered successfully and their numbers increased rapidly producing a peak during the breeding season.

  3. Primitive Solar System materials and Earth share a common initial 142Nd abundance (United States)

    Bouvier, A.; Boyet, M.


    The early evolution of planetesimals and planets can be constrained using variations in the abundance of neodymium-142 (142Nd), which arise from the initial distribution of 142Nd within the protoplanetary disk and the radioactive decay of the short-lived samarium-146 isotope (146Sm). The apparent offset in 142Nd abundance found previously between chondritic meteorites and Earth has been interpreted either as a possible consequence of nucleosynthetic variations within the protoplanetary disk or as a function of the differentiation of Earth very early in its history. Here we report high-precision Sm and Nd stable and radiogenic isotopic compositions of four calcium-aluminium-rich refractory inclusions (CAIs) from three CV-type carbonaceous chondrites, and of three whole-rock samples of unequilibrated enstatite chondrites. The CAIs, which are the first solids formed by condensation from the nebular gas, provide the best constraints for the isotopic evolution of the early Solar System. Using the mineral isochron method for individual CAIs, we find that CAIs without isotopic anomalies in Nd compared to the terrestrial composition share a 146Sm/144Sm-142Nd/144Nd isotopic evolution with Earth. The average 142Nd/144Nd composition for pristine enstatite chondrites that we calculate coincides with that of the accessible silicate layers of Earth. This relationship between CAIs, enstatite chondrites and Earth can only be a result of Earth having inherited the same initial abundance of 142Nd and chondritic proportions of Sm and Nd. Consequently, 142Nd isotopic heterogeneities found in other CAIs and among chondrite groups may arise from extrasolar grains that were present in the disk and incorporated in different proportions into these planetary objects. Our finding supports a chondritic Sm/Nd ratio for the bulk silicate Earth and, as a consequence, chondritic abundances for other refractory elements. It also removes the need for a hidden reservoir or for collisional erosion

  4. Primitive Solar System materials and Earth share a common initial (142)Nd abundance. (United States)

    Bouvier, A; Boyet, M


    The early evolution of planetesimals and planets can be constrained using variations in the abundance of neodymium-142 ((142)Nd), which arise from the initial distribution of (142)Nd within the protoplanetary disk and the radioactive decay of the short-lived samarium-146 isotope ((146)Sm). The apparent offset in (142)Nd abundance found previously between chondritic meteorites and Earth has been interpreted either as a possible consequence of nucleosynthetic variations within the protoplanetary disk or as a function of the differentiation of Earth very early in its history. Here we report high-precision Sm and Nd stable and radiogenic isotopic compositions of four calcium-aluminium-rich refractory inclusions (CAIs) from three CV-type carbonaceous chondrites, and of three whole-rock samples of unequilibrated enstatite chondrites. The CAIs, which are the first solids formed by condensation from the nebular gas, provide the best constraints for the isotopic evolution of the early Solar System. Using the mineral isochron method for individual CAIs, we find that CAIs without isotopic anomalies in Nd compared to the terrestrial composition share a (146)Sm/(144)Sm-(142)Nd/(144)Nd isotopic evolution with Earth. The average (142)Nd/(144)Nd composition for pristine enstatite chondrites that we calculate coincides with that of the accessible silicate layers of Earth. This relationship between CAIs, enstatite chondrites and Earth can only be a result of Earth having inherited the same initial abundance of (142)Nd and chondritic proportions of Sm and Nd. Consequently, (142)Nd isotopic heterogeneities found in other CAIs and among chondrite groups may arise from extrasolar grains that were present in the disk and incorporated in different proportions into these planetary objects. Our finding supports a chondritic Sm/Nd ratio for the bulk silicate Earth and, as a consequence, chondritic abundances for other refractory elements. It also removes the need for a hidden reservoir or

  5. The Origin of the Metal-Poor Common Proper Motion Pair HD 134439/134440: Insights from New Elemental Abundances

    CERN Document Server

    Chen, Yu; Boesgaard, Ann M


    The low [alpha/Fe] ratio in the metal-poor ([Fe/H]= -1.50) common proper motion pair HD 134439 and HD 134440 has been variously attributed to chemical evolution in an extragalactic environment with an irregular star formation history, planetessimal accretion, and formation in an environment with an unusually high dust-to-gas ratio. We explore these various putative origins using CNO, Be, Ag, and Eu abundances derived from high-resolution near-UV Keck/HIRES spectroscopy. While we confirm a previously suggested correlation between elemental abundance ratios and condensation temperature at the 95% confidence level, these ratios lie within the continuum of values manifested by extant dSph data. We argue that the most plausible origin of our stars' distinctive abundance distribution relative to the Galactic halo field is formation in an environment chemically dominated by products of Type II SN of low progenitor mass; such a progenitor mass bias has been previously suggested as an explanation of low alpha-element ...

  6. Livestock grazing intensity affects abundance of Common shrews (Sorex araneus) in two meadows in Denmark

    DEFF Research Database (Denmark)

    Schmidt, Niels Martin; Olsen, Henrik; Leirs, Herwig


    habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results: High grazing...... shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool. Background In Denmark...... habitat types for a large number of animal species in today's fragmented and intensively cultivated landscape in Europe. Hay cutting and livestock grazing is known to affect a number of organisms, but the response to grazing may vary across classes of organisms and with the intensity of Published: 20...

  7. 基于16S和23S rDNA基因芯片检测和鉴定七种临床常见病原菌%Detection and identification of seven clinical common pathogenic bacteria by oligonucleotide microarray

    Institute of Scientific and Technical Information of China (English)

    邢建明; 张甦; 张红河; 沈翠芬; 毕丹; 李刚; 姚丽惠


    Objective Using 16S rDNA and 23S rDNA genes as the target sequences to develop a system based on oligonucleotide microarray and to detect the seven clinical pathogenic bacteria, commonly seen. Methods Double polymerase chain reaction(PCR) was applied to amplify the segments of 16S rDNA and 23S rDNA genes of the target bacteria. An oligonucleotide microarray was constructed to simultaneously detect EHEC O157:H7, Vibrio parahaemolyticus , Saimonella sp., Vibrio cholerae ,Listeria monocytogenes, Campylobacter jejuni and Shigella sp. Specificity, sensitivity and reproducibility of the microarray during detection were checked. And then microarray was used to detect the microbes in stool specimens of 81 patients with diarrhea and vomiting. Results The double PCR method could simultaneously amplify the target sequences of 16S rDNA and 23S rDNA genes of the seven pathogens. The sensitivity of the developed oligonueleotide microarray could reach 103 cfu/ml but no positive results were presented for non-targeted bacteria. The coefficients of differentiation in one lot or among different lots of the microarray slices were 3.89%-5.81%. The positive detection rate of the stool specimens by oligonucleotide microarray was 39.5 % (32/81), with a coincidence of 96.3 % (78/81) for the patients and another coincidence of 96.8% (31/32) for bacterial genus or species identification, when comparing to the results by routine bacteriological examinations. Conclusion The established assay in this study based on oligonucleotide microarray to detect the seven pathogenic bacteria has many advantages such as convenient,rapid, accurate, stable and high flux, which is suitable for clinical specimen examination and epidemiological field investigation.%目的 以细菌16S rDNA和23S rDNA基因为靶序列建立可检测临床七种常见病原菌寡核苷酸芯片系统.方法 采用双重PCR扩增标本中靶细菌16S和23S rDNA基因片段.构建能同时检测肠出血性大肠埃希菌O157:H7

  8. Peptide-LNA oligonucleotide conjugates

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Hansen, Lykke Haastrup; Vester, Birte


    properties, peptides were introduced into oligonucleotides via a 2'-alkyne-2'-amino-LNA scaffold. Derivatives of methionine- and leucine-enkephalins were chosen as model peptides of mixed amino acid content, which were singly and doubly incorporated into LNA/DNA strands using highly efficient copper......Although peptide-oligonucleotide conjugates (POCs) are well-known for nucleic acids delivery and therapy, reports on internal attachment of peptides to oligonucleotides are limited in number. To develop a convenient route for preparation of internally labeled POCs with improved biomedical......(i)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" chemistry. DNA/RNA target binding affinity and selectivity of the resulting POCs were improved in comparison to LNA/DNA mixmers and unmodified DNA controls. This clearly demonstrates that internal attachment of peptides to oligonucleotides can significantly...

  9. Abundant occurrence of basal radial glia in the subventricular zone of embryonic neocortex of a lissencephalic primate, the common marmoset Callithrix jacchus. (United States)

    Kelava, Iva; Reillo, Isabel; Murayama, Ayako Y; Kalinka, Alex T; Stenzel, Denise; Tomancak, Pavel; Matsuzaki, Fumio; Lebrand, Cécile; Sasaki, Erika; Schwamborn, Jens C; Okano, Hideyuki; Huttner, Wieland B; Borrell, Víctor


    Subventricular zone (SVZ) progenitors are a hallmark of the developing neocortex. Recent studies described a novel type of SVZ progenitor that retains a basal process at mitosis, sustains expression of radial glial markers, and is capable of self-renewal. These progenitors, referred to here as basal radial glia (bRG), occur at high relative abundance in the SVZ of gyrencephalic primates (human) and nonprimates (ferret) but not lissencephalic rodents (mouse). Here, we analyzed the occurrence of bRG cells in the embryonic neocortex of the common marmoset Callithrix jacchus, a near-lissencephalic primate. bRG cells, expressing Pax6, Sox2 (but not Tbr2), glutamate aspartate transporter, and glial fibrillary acidic protein and retaining a basal process at mitosis, occur at similar relative abundance in the marmoset SVZ as in human and ferret. The proportion of progenitors in M-phase was lower in embryonic marmoset than developing ferret neocortex, raising the possibility of a longer cell cycle. Fitting the gyrification indices of 26 anthropoid species to an evolutionary model suggested that the marmoset evolved from a gyrencephalic ancestor. Our results suggest that a high relative abundance of bRG cells may be necessary, but is not sufficient, for gyrencephaly and that the marmoset's lissencephaly evolved secondarily by changing progenitor parameters other than progenitor type.

  10. 'Specific' oligonucleotides often recognize more than one gene: the limits of in situ hybridization applied to GABA receptors. (United States)

    Mladinic, M; Didelon, F; Cherubini, E; Bradbury, A


    As exquisite probes for gene sequences, oligonucleotides are one of the most powerful tools of recombinant molecular biology. In studying the GABA receptor subunits in the neonatal hippocampus we have used oligonucleotide probes in in situ hybridization and cloning techniques. The oligonucleotides used and assumed to be specific for the target gene, actually recognized more than one gene, leading to surprising and contradictory results. In particular, we found that a GABA(A)-rho specific oligonucleotide recognized an abundant, previously unknown, transcription factor in both in situ and library screening, while oligos 'specific' for GABA(A) subunits were able to recognize 30 additional unrelated genes in library screening. This suggests that positive results obtained with oligonucleotides should be interpreted with caution unless confirmed by identical results with oligonucleotides from different parts of the same gene, or cDNA library screening excludes the presence of other hybridizing species.

  11. Thermodynamics of Oligonucleotide Duplex Melting (United States)

    Schreiber-Gosche, Sherrie; Edwards, Robert A.


    Melting temperatures of oligonucleotides are useful for a number of molecular biology applications, such as the polymerase chain reaction (PCR). Although melting temperatures are often calculated with simplistic empirical equations, application of thermodynamics provides more accurate melting temperatures and an opportunity for students to apply…

  12. Influence of the root system of the Common Osier (Salix viminalis L.) on abundance of heterotrophic bacteria in the willow sewage treatment system. (United States)

    Lalke-Porczyk, Elzbieta; Brzezinska, Maria Swiontek; Donderski, Wojciech


    The impact of the Common Osier (Salix viminalis L.) root system on number (CFU) of heterotrophic bacteria and their production in a soil-willow filter was examined. The Osier rhizosphere was found to be suitable habitat for growth of the examined microbial group, and the root system stimulated development of heterotrophic bacteria. The rhizosphere bacteria to control soil bacteria (R:C) ratio oscillated between 2.48 and 2.75 depending on the location of sample collection. The highest abundance of bacteria as well as highest bacterial production was observed at location I, near sewage discharge onto the plot. There was a significant positive correlation between the number of heterotrophic bacteria and the bacterial production.

  13. Oligonucleotide Therapy for Obstructive and Restrictive Respiratory Diseases. (United States)

    Liao, Wupeng; Dong, Jinrui; Peh, Hong Yong; Tan, Lay Hong; Lim, Kah Suan; Li, Li; Wong, Wai-Shiu Fred


    Inhaled oligonucleotide is an emerging therapeutic modality for various common respiratory diseases, including obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD) and restrictive airway diseases like idiopathic pulmonary fibrosis (IPF). The advantage of direct accessibility for oligonucleotide molecules to the lung target sites, bypassing systemic administration, makes this therapeutic approach promising with minimized potential systemic side effects. Asthma, COPD, and IPF are common chronic respiratory diseases, characterized by persistent airway inflammation and dysregulated tissue repair and remodeling, although each individual disease has its unique etiology. Corticosteroids have been widely prescribed for the treatment of asthma, COPD, and IPF. However, the effectiveness of corticosteroids as an anti-inflammatory drug is limited by steroid resistance in severe asthma, the majority of COPD cases, and pulmonary fibrosis. There is an urgent medical need to develop target-specific drugs for the treatment of these respiratory conditions. Oligonucleotide therapies, including antisense oligonucleotide (ASO), small interfering RNA (siRNA), and microRNA (miRNA) are now being evaluated both pre-clinically and clinically as potential therapeutics. The mechanisms of action of ASO and siRNA are highly target mRNA specific, ultimately leading to target protein knockdown. miRNA has both biomarker and therapeutic values, and its knockdown by a miRNA antagonist (antagomir) has a broader but potentially more non-specific biological outcome. This review will compile the current findings of oligonucleotide therapeutic targets, verified in various respiratory disease models and in clinical trials, and evaluate different chemical modification approaches to improve the stability and potency of oligonucleotides for the treatment of respiratory diseases.

  14. Oligonucleotide Therapy for Obstructive and Restrictive Respiratory Diseases

    Directory of Open Access Journals (Sweden)

    Wupeng Liao


    Full Text Available Inhaled oligonucleotide is an emerging therapeutic modality for various common respiratory diseases, including obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD and restrictive airway diseases like idiopathic pulmonary fibrosis (IPF. The advantage of direct accessibility for oligonucleotide molecules to the lung target sites, bypassing systemic administration, makes this therapeutic approach promising with minimized potential systemic side effects. Asthma, COPD, and IPF are common chronic respiratory diseases, characterized by persistent airway inflammation and dysregulated tissue repair and remodeling, although each individual disease has its unique etiology. Corticosteroids have been widely prescribed for the treatment of asthma, COPD, and IPF. However, the effectiveness of corticosteroids as an anti-inflammatory drug is limited by steroid resistance in severe asthma, the majority of COPD cases, and pulmonary fibrosis. There is an urgent medical need to develop target-specific drugs for the treatment of these respiratory conditions. Oligonucleotide therapies, including antisense oligonucleotide (ASO, small interfering RNA (siRNA, and microRNA (miRNA are now being evaluated both pre-clinically and clinically as potential therapeutics. The mechanisms of action of ASO and siRNA are highly target mRNA specific, ultimately leading to target protein knockdown. miRNA has both biomarker and therapeutic values, and its knockdown by a miRNA antagonist (antagomir has a broader but potentially more non-specific biological outcome. This review will compile the current findings of oligonucleotide therapeutic targets, verified in various respiratory disease models and in clinical trials, and evaluate different chemical modification approaches to improve the stability and potency of oligonucleotides for the treatment of respiratory diseases.

  15. Thermodynamic treatment of oligonucleotide duplex–simplex equilibria (United States)

    Owczarzy, Richard; Dunietz, Isard; Behlke, Mark A.; Klotz, Irving M.; Walder, Joseph A.


    Thermodynamic formulations have been devised to obtain ΔG° values directly from spectroscopic data at a fixed common temperature in nucleic acid duplex–simplex melting curves. In addition, the dependence of melting on salt concentration has been expressed in terms of a stepwise stoichiometric representation, which leads to a specific equation for the partition of the added sodium ions between the different oligonucleotide forms. PMID:14657395

  16. Oligonucleotide therapeutics: chemistry, delivery and clinical progress. (United States)

    Sharma, Vivek K; Watts, Jonathan K


    Oligonucleotide therapeutics have the potential to become a third pillar of drug development after small molecules and protein therapeutics. However, the three approved oligonucleotide drugs over the past 17 years have not proven to be highly successful in a commercial sense. These trailblazer drugs have nonetheless laid the foundations for entire classes of drug candidates to follow. This review will examine further advances in chemistry that are earlier in the pipeline of oligonucleotide drug candidates. Finally, we consider the possible effect of delivery systems that may provide extra footholds to improve the potency and specificity of oligonucleotide drugs. Our overview focuses on strategies to imbue antisense oligonucleotides with more drug-like properties and their applicability to other nucleic acid therapeutics.

  17. Adaptive resolution simulation of oligonucleotides (United States)

    Netz, Paulo A.; Potestio, Raffaello; Kremer, Kurt


    Nucleic acids are characterized by a complex hierarchical structure and a variety of interaction mechanisms with other molecules. These features suggest the need of multiscale simulation methods in order to grasp the relevant physical properties of deoxyribonucleic acid (DNA) and RNA using in silico experiments. Here we report an implementation of a dual-resolution modeling of a DNA oligonucleotide in physiological conditions; in the presented setup only the nucleotide molecule and the solvent and ions in its proximity are described at the atomistic level; in contrast, the water molecules and ions far from the DNA are represented as computationally less expensive coarse-grained particles. Through the analysis of several structural and dynamical parameters, we show that this setup reliably reproduces the physical properties of the DNA molecule as observed in reference atomistic simulations. These results represent a first step towards a realistic multiscale modeling of nucleic acids and provide a quantitatively solid ground for their simulation using dual-resolution methods.

  18. Common Carp Abundance, Biomass, and Removal from Dewey and Clear Lakes on the Valentine National Wildlife Refuge: Does Trapping and Removing Carp Payoff? (United States)

    US Fish and Wildlife Service, Department of the Interior — Common carp Cyprinus carpio is a nonnative invasive nuisance species to North America. Many authors have documented the detrimental affects of common carp invasions...

  19. G-Quadruplex Forming Oligonucleotides as Anti-HIV Agents. (United States)

    Musumeci, Domenica; Riccardi, Claudia; Montesarchio, Daniela


    Though a variety of different non-canonical nucleic acids conformations have been recognized, G-quadruplex structures are probably the structural motifs most commonly found within known oligonucleotide-based aptamers. This could be ascribed to several factors, as their large conformational diversity, marked responsiveness of their folding/unfolding processes to external stimuli, high structural compactness and chemo-enzymatic and thermodynamic stability. A number of G-quadruplex-forming oligonucleotides having relevant in vitro anti-HIV activity have been discovered in the last two decades through either SELEX or rational design approaches. Improved aptamers have been obtained by chemical modifications of natural oligonucleotides, as terminal conjugations with large hydrophobic groups, replacement of phosphodiester linkages with phosphorothioate bonds or other surrogates, insertion of base-modified monomers, etc. In turn, detailed structural studies have elucidated the peculiar architectures adopted by many G-quadruplex-based aptamers and provided insight into their mechanism of action. An overview of the state-of-the-art knowledge of the relevance of putative G-quadruplex forming sequences within the viral genome and of the most studied G-quadruplex-forming aptamers, selectively targeting HIV proteins, is here presented.

  20. Differentiation of regions with atypical oligonucleotide composition in bacterial genomes

    Directory of Open Access Journals (Sweden)

    Reva Oleg N


    Full Text Available Abstract Background Complete sequencing of bacterial genomes has become a common technique of present day microbiology. Thereafter, data mining in the complete sequence is an essential step. New in silico methods are needed that rapidly identify the major features of genome organization and facilitate the prediction of the functional class of ORFs. We tested the usefulness of local oligonucleotide usage (OU patterns to recognize and differentiate types of atypical oligonucleotide composition in DNA sequences of bacterial genomes. Results A total of 163 bacterial genomes of eubacteria and archaea published in the NCBI database were analyzed. Local OU patterns exhibit substantial intrachromosomal variation in bacteria. Loci with alternative OU patterns were parts of horizontally acquired gene islands or ancient regions such as genes for ribosomal proteins and RNAs. OU statistical parameters, such as local pattern deviation (D, pattern skew (PS and OU variance (OUV enabled the detection and visualization of gene islands of different functional classes. Conclusion A set of approaches has been designed for the statistical analysis of nucleotide sequences of bacterial genomes. These methods are useful for the visualization and differentiation of regions with atypical oligonucleotide composition prior to or accompanying gene annotation.

  1. An oligonucleotide hybridization approach to DNA sequencing. (United States)

    Khrapko, K R; Lysov YuP; Khorlyn, A A; Shick, V V; Florentiev, V L; Mirzabekov, A D


    We have proposed a DNA sequencing method based on hybridization of a DNA fragment to be sequenced with the complete set of fixed-length oligonucleotides (e.g., 4(8) = 65,536 possible 8-mers) immobilized individually as dots of a 2-D matrix [(1989) Dokl. Akad. Nauk SSSR 303, 1508-1511]. It was shown that the list of hybridizing octanucleotides is sufficient for the computer-assisted reconstruction of the structures for 80% of random-sequence fragments up to 200 bases long, based on the analysis of the octanucleotide overlapping. Here a refinement of the method and some experimental data are presented. We have performed hybridizations with oligonucleotides immobilized on a glass plate, and obtained their dissociation curves down to heptanucleotides. Other approaches, e.g., an additional hybridization of short oligonucleotides which continuously extend duplexes formed between the fragment and immobilized oligonucleotides, should considerably increase either the probability of unambiguous reconstruction, or the length of reconstructed sequences, or decrease the size of immobilized oligonucleotides.

  2. Estimation of phenotypic variability in symbiotic nitrogen fixation ability of common bean under drought stress using 15N natural abundance in grain


    Polania, Jose; Poschenrieder, Charlotte; Rao, Idupulapati; Beebe, Stephen


    Common bean (Phaseolus vulgaris L.) is the most important food legume, cultivated by small farmers and is usually exposed to unfavorable conditions with minimum use of inputs. Drought and low soil fertility, especially phosphorus and nitrogen (N) deficiencies, are major limitations to bean yield in smallholder systems. Beans can derive part of their required N from the atmosphere through symbiotic nitrogen fixation (SNF). Drought stress severely limits SNF ability of plants. The main objectiv...

  3. Abundance distribution of common and rare plant species of Brazilian savannas along a seasonality gradient Distribuição de abundâncias de espécies de plantas comuns e raras de savanas brasileiras ao longo de um gradiente de estacionalidade

    Directory of Open Access Journals (Sweden)

    Igor Aurélio Silva


    Full Text Available We examined the species abundance distribution (SAD of plant communities in: (1 a wet grassland, waterlogged throughout most of the year; (2 a seasonal savanna, with an annual dry season; and (3 a hyperseasonal savanna, with alternating drought and waterlogging over the year. We searched for differences in the abundance distributions of all species, as well as of the common and rare species. We tested whether the SADs fitted the lognormal, log-series, power fraction, and random assortment models. We found that environmental constraints may reduce the evenness of plant communities and change the SADs in savannas. We observed a lognormal abundance distribution in the wet grassland and a random abundance distribution in the hyperseasonal cerrado. The SAD of the seasonal savanna did not follow any model. The common species in the three communities were better fitted by the lognormal model. The rare species in the wet grassland and the hyperseasonal cerrado were better fitted by the random assortment model. The SAD of the rare species of the seasonal savanna did not follow any model. Seasonality seems to modify the lognormal distribution of the overall plant community, generating abundance distributions indistinguishable from random. However, differential community structuring between common and rare species may not be affected by seasonality. The different signatures of the abundance distributions of common and rare plants indicate that composite models are better predictors for SADs in savannas.Examinamos as distribuições de abundâncias de espécies (DAEs de comunidades de plantas em: (1 um campo úmido, alagado durante a maior parte do ano; (2 uma savana estacional, com uma estação seca anual; e (3 uma savana hiper-estacional, com uma estação seca e um alagamento alternantes durante o ano. Procuramos por diferenças na distribuição de abundância de todas as espécies, bem como das espécies comuns e raras. Testamos se as DAEs se

  4. Construction and Evaluation of Desulfovibrio vulgaris Whole-Genome Oligonucleotide Microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Z. He; Q. He; L. Wu; M.E. Clark; J.D. Wall; Jizhong Zhou; Matthew W. Fields


    ,4-cyclodiphosphate (MECDP) synthase. Spermidines are polyamines that are typically abundant in rapidly dividing cells and are essential growth factors in eukaryotic organisms. Polyamines are thought to stabilize DNA by the association of the amino groups with the phosphate residues of DNA and can also enhance tRNA and ribosome stability. The MECDP synthase enzyme is essential in Escherichia coli and participates in the nonmevalonate pathway of isoprenoid biosynthesis, a critical pathway present in some bacteria and apicomplexans but distinct from that used by mammals. Several of the highly up-regulated ORFs were annotated as conserved hypothetical proteins. Interestingly, an ORF that was predicted to contain a flocculin repeat domain was almost 9-fold up-regulated in stationary phase cells compared to logarithmically growing cells. The flocculin domain is commonly observed in fungi, and is thought to play a role during flocculation (non-sexual aggregation of single-cell microorganisms). These preliminary results have identified possible responses of D. vulgaris cells to stationary phase growth and suggest that polyamine production as well as cell aggregation and/or extracellular polymer production are responses of D. vulgaris during stationary phase. The initial microarray results indicate that the recently produced oligonucleotide microarrays are functional. We are currently optimizing growth conditions in order to culture D. vulgaris cells in the presence of uranium(VI) and to monitor whole-genome expression levels.

  5. Transcript copy number estimation using a mouse whole-genome oligonucleotide microarray


    Carter, Mark G.; Sharov, Alexei A; VanBuren, Vincent; Dudekula, Dawood B.; Carmack, Condie E; Nelson, Charlie; Ko, Minoru SH


    The ability to quantitatively measure the expression of all genes in a given tissue or cell with a single assay is an exciting promise of gene-expression profiling technology. An in situ-synthesized 60-mer oligonucleotide microarray designed to detect transcripts from all mouse genes was validated, as well as a set of exogenous RNA controls derived from the yeast genome (made freely available without restriction), which allow quantitative estimation of absolute endogenous transcript abundance.

  6. Transcript copy number estimation using a mouse whole-genome oligonucleotide microarray (United States)

    Carter, Mark G; Sharov, Alexei A; VanBuren, Vincent; Dudekula, Dawood B; Carmack, Condie E; Nelson, Charlie; Ko, Minoru SH


    The ability to quantitatively measure the expression of all genes in a given tissue or cell with a single assay is an exciting promise of gene-expression profiling technology. An in situ-synthesized 60-mer oligonucleotide microarray designed to detect transcripts from all mouse genes was validated, as well as a set of exogenous RNA controls derived from the yeast genome (made freely available without restriction), which allow quantitative estimation of absolute endogenous transcript abundance. PMID:15998450

  7. Cellular uptake of antisense oligonucleotides after complexing or conjugation with cell-penetrating model peptides. (United States)

    Oehlke, J; Birth, P; Klauschenz, E; Wiesner, B; Beyermann, M; Oksche, A; Bienert, M


    The uptake by mammalian cells of phosphorothioate oligonucleotides was compared with that of their respective complexes or conjugates with cationic, cell-penetrating model peptides of varying helix-forming propensity and amphipathicity. An HPLC-based protocol for the synthesis and purification of disulfide bridged conjugates in the 10-100 nmol range was developed. Confocal laser scanning microscopy (CLSM) in combination with gel-capillary electrophoresis and laser induced fluorescence detection (GCE-LIF) revealed cytoplasmic and nuclear accumulationin all cases. The uptake differences between naked oligonucleotides and their respective peptide complexes or conjugates were generally confined to one order of magnitude. No significant influence of the structural properties of the peptide components upon cellular uptake was found. Our results question the common belief that the increased biological activity of oligonucleotides after derivatization with membrane permeable peptides may be primarily due to improved membrane translocation.

  8. Chemosensitization by antisense oligonucleotides targeting MDM2. (United States)

    Bianco, Roberto; Ciardiello, Fortunato; Tortora, Giampaolo


    The MDM2 oncogene is overexpressed in many human cancers, including sarcomas, certain hematologic malignancies, and breast, colon and prostate cancers. The p53-MDM2 interaction pathway has been suggested as a novel target for cancer therapy. To that end, several strategies have been explored, including the use of small polypeptides targeted to the MDM2-p53 binding domain, anti-MDM2 antisense oligonucleotides, and natural agents. Different generations of anti-human-MDM2 oligonucleotides have been tested in in vitro and in vivo human cancer models, revealing specific inhibition of MDM2 expression and significant antitumor activity. Use of antisense oligos potentiated the effects of growth inhibition, p53 activation and p21 induction by several chemotherapeutic agents. Increased therapeutic effectiveness of chemotherapeutic drugs in human cancer cell lines carrying p53 mutations or deletions have shown the ability of MDM2 inhibitors to act as chemosensitizers in various types of tumors through both p53-dependent and p53-independent mechanisms. Inhibiting MDM2 appears to also have a role in radiation therapy for human cancer, regardless of p53 status, providing a rationale for the development of a new class of radiosensitizers. Moreover, MDM2 antisense oligonucleotides potentiate the effect of epidermal growth factor receptor (EGFR) inhibitors by affecting in vitro and in vivo proliferation, apoptosis and protein expression in hormone-refractory and hormone-dependent human prostate cancer cells. These data support the development, among other MDM2 inhibitors, of anti-MDM2 antisense oligonucleotides as a novel class of anticancer agents, and suggest a potentially relevant role for the oligonucleotides when integrated with conventional treatments and/or other signaling inhibitors in novel therapeutic strategies.

  9. Antisense oligonucleotides in therapy for neurodegenerative disorders. (United States)

    Evers, Melvin M; Toonen, Lodewijk J A; van Roon-Mom, Willeke M C


    Antisense oligonucleotides are synthetic single stranded strings of nucleic acids that bind to RNA and thereby alter or reduce expression of the target RNA. They can not only reduce expression of mutant proteins by breakdown of the targeted transcript, but also restore protein expression or modify proteins through interference with pre-mRNA splicing. There has been a recent revival of interest in the use of antisense oligonucleotides to treat several neurodegenerative disorders using different approaches to prevent disease onset or halt disease progression and the first clinical trials for spinal muscular atrophy and amyotrophic lateral sclerosis showing promising results. For these trials, intrathecal delivery is being used but direct infusion into the brain ventricles and several methods of passing the blood brain barrier after peripheral administration are also under investigation.

  10. Common Eider - Avian Average Annual Abundance (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  11. Common Loon - Avian Average Annual Abundance (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  12. Common Tern - Avian Average Annual Abundance (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  13. Electrochemical study of hepta–oligonucleotides

    Directory of Open Access Journals (Sweden)

    Zdenka Balcarova


    Full Text Available The study deals with the description and characterization of twohepta–oligonucleotides (DNA and RNA forming special structures.We studied their electrochemical behaviour by means of cyclicvoltammetry (CV and elimination voltammetry with linear scan(EVLS in combination with adsorptive stripping (AdS technique.Differences in electrochemical behaviour of hepta–deoxyribonucleotide and its RNA analog were discussed with regardto their different structures in solutions and their melting points.

  14. Synthesis and hybridization properties of inverse oligonucleotides.


    Marangoni, M.; Van Aerschot, Arthur; Augustijns, Patrick; Rozenski, Jef; Herdewijn , Piet


    The synthesis of adenine and thymine cyclopentylethyl nucleosides is presented. This novel constrained monomeric building block is very difficult to incorporate into oligonucleotides. It was introduced in 13mer oligodeoxynucleotide sequences at a single position using H-phosphonate chemistry. Phosphoramidite chemistry completely failed in this particular case. The H-phosphonate building blocks were obtained starting from the corresponding phosphoramidites. Stability of duplexes with RNA and D...

  15. Comparison of small molecules and oligonucleotides that target a toxic, non-coding RNA. (United States)

    Costales, Matthew G; Rzuczek, Suzanne G; Disney, Matthew D


    Potential RNA targets for chemical probes and therapeutic modalities are pervasive in the transcriptome. Oligonucleotide-based therapeutics are commonly used to target RNA sequence. Small molecules are emerging as a modality to target RNA structures selectively, but their development is still in its infancy. In this work, we compare the activity of oligonucleotides and several classes of small molecules that target the non-coding r(CCUG) repeat expansion (r(CCUG)(exp)) that causes myotonic dystrophy type 2 (DM2), an incurable disease that is the second-most common cause of adult onset muscular dystrophy. Small molecule types investigated include monomers, dimers, and multivalent compounds synthesized on-site by using RNA-templated click chemistry. Oligonucleotides investigated include phosphorothioates that cleave their target and vivo-morpholinos that modulate target RNA activity via binding. We show that compounds assembled on-site that recognize structure have the highest potencies amongst small molecules and are similar in potency to a vivo-morpholino modified oligonucleotide that targets sequence. These studies are likely to impact the design of therapeutic modalities targeting other repeats expansions that cause fragile X syndrome and amyotrophic lateral sclerosis, for example.

  16. Pericellular matrix formation alters the efficiency of intracellular uptake of oligonucleotides in osteosarcoma cells. (United States)

    Suzuki, Yoshitaka; Nishida, Yoshihiro; Naruse, Takahiro; Gemba, Takefumi; Ishiguro, Naoki


    One of the crucial roles of tumor extracellular matrix is to act as a barrier to drug delivery. In this study, we analyzed the relationship between the formation of tumor extracellular matrix and the efficiency of intracellular uptake of oligonucleotides in human osteosarcoma cell lines, HOS, and MG-63. Oligonucleotides used in this study were nuclear factor-kappa B (NF-kappaB) decoy, which might be a therapeutic tool for neoplasms. Pericellular matrix formation was examined by particle exclusion assay. Cellular uptake of fluorescein isothiocyanate-labeled NF-kappaB decoy was evaluated by fluorescent microscopy and flow cytometry. Effects of NF-kappaB decoy on cell viability and cell cycle arrest in MG-63 cells were determined by MTT assay and flow cytometry, respectively. MG-63 cells exhibited abundant pericellular matrix with time compared with HOS cells. Uptake of fluorescein isothiocyanate-labeled NF-kappaB decoy decreased in MG-63 cells with time but not in HOS cells in both monolayer and three-dimensional culture using matrigel. However, after enzymatic removal of pericellular matrix, the uptake markedly recovered in MG-63 cells. NF-kappaB decoy inhibited cell proliferation and induced G0/G1 cell cycle arrest in MG-63 cells. These results suggest that abundant pericellular matrix might disturb the uptake of NF-kappaB decoy, and modification of pericellular matrix composition would increase the efficacy of exogenous oligonucleotides treatment for neoplasms.

  17. Heated oligonucleotide ligation assay (HOLA): an affordable single nucleotide polymorphism assay. (United States)

    Black, W C; Gorrochotegui-Escalante, N; Duteau, N M


    Most single nucleotide polymorphism (SNP) detection requires expensive equipment and reagents. The oligonucleotide ligation assay (OLA) is an inexpensive SNP assay that detects ligation between a biotinylated "allele-specific detector" and a 3' fluorescein-labeled "reporter" oligonucleotide. No ligation occurs unless the 3' detector nucleotide is complementary to the SNP nucleotide. The original OLA used chemical denaturation and neutralization. Heated OLA (HOLA) instead uses a thermal stable ligase and cycles of denaturing and hybridization for ligation and SNP detection. The cost per genotype is approximately US$1.25 with two-allele SNPs or approximately US$1.75 with three-allele SNPs. We illustrate the development of HOLA for SNP detection in the Early Trypsin and Abundant Trypsin loci in the mosquito Aedes aegypti (L.) and at the a-glycerophosphate dehydrogenase locus in the mosquito Anopheles gambiae s.s.

  18. Application of heteronuclear couplings to conformational analysis of oligonucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, G. [Univ. of Maryland, College Park, MD (United States); Live, D. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Bax, A. [NIDDK National Institutes of Health, Bethesda, MD (United States)


    The value of vicinal coupling constants extracted from NMR spectra in deducing torsion angles for conformational analysis is well recognized. Due to the abundance of protons, their couplings have been mostly widely used. In many instances, couplings between protons and other nuclei may be a valuable complement to proton-proton couplings or, in some instances, may be the only coupling available to characterize the torsion angle about a bond. Recently, heteronuclear couplings have been used to great benefit in studies of isotopically enriched proteins, and this general approach has been extended to peptides at natural abundance. The possibility of using this approach to study oligonucleotides is also attractive but has not as yet been widely exploited. With the development of strategies for labeling such molecules, particularly RNAs, this may become an important component in conformational analysis. For DNA, labeling is less accessible, but sufficient quantities of unlabeled material are readily available for measuring these couplings at natural abundance. We chose several DNA systems to explore the usefulness of heteronuclear couplings in addressing the sugar conformation and the glycosidic torsion angle. Intensities of cross peaks in long-range HMQC experiments can be related to the couplings. Crosspeaks involving H1{prime} and C1{prime} atoms have been emphasized because of the superior shift dispersion at these positions between sugar protons and carbon atoms. Results will be shown for the self-complementary Dickerson duplex dodecamer sequence d(CGCGAATTCGCG) and for d(GGTCGG), which dimerizes to form a G-tetrad structure incorporating both syn and anti base orientations. The couplings provide a clear discrimination between presence of C3{prime}-endo and C2{prime}-endo conformations of the sugars and syn and anti bases arrangements.

  19. Template-Directed Ligation of Peptides to Oligonucleotides (United States)

    Bruick, Richard K.; Dawson, Philip E.; Kent, Stephen BH; Usman, Nassim; Joyce, Gerald F.


    Synthetic oligonucleotides and peptides have enjoyed a wide range of applications in both biology and chemistry. As a consequence, oligonucleotide-peptide conjugates have received considerable attention, most notably in the development of antisense constructs with improved pharmacological properties. In addition, oligonucleotide-peptide conjugates have been used as molecular tags, in the assembly of supramolecular arrays and in the construction of encoded combinatorial libraries. To make these chimeric molecules more accessible for a broad range of investigations, we sought to develop a facile method for joining fully deprotected oligonucleotides and peptides through a stable amide bond linkage. Furthermore, we wished to make this ligation reaction addressable, enabling one to direct the ligation of specific oligonucleotide and peptide components.To confer specificity and accelerate the rate of the reaction, the ligation process was designed to be dependent on the presence of a complementary oligonucleotide template.

  20. Recommendations for safety pharmacology evaluations of oligonucleotide-based therapeutics. (United States)

    Berman, Cindy L; Cannon, Keri; Cui, Yi; Kornbrust, Douglas J; Lagrutta, Armando; Sun, Sunny Z; Tepper, Jeff; Waldron, Gareth; Younis, Husam S


    This document was prepared by the Safety Pharmacology Subcommittee of the Oligonucleotide Safety Working Group (OSWG), a group of industry and regulatory scientists involved in the development and regulation of therapeutic oligonucleotides. The mission of the Subcommittee was to develop scientific recommendations for the industry regarding the appropriate scope and strategies for safety pharmacology evaluations of oligonucleotides (ONs). These recommendations are the consensus opinion of the Subcommittee and do not necessarily reflect the current expectations of regulatory authorities. 1) Safety pharmacology testing, as described in the International Conference on Harmonisation (ICH) S7 guidance, is as applicable to ONs as it is to small molecule drugs and biotherapeutics. 2) Study design considerations for ONs are similar to those for other classes of drugs. In general, as with other therapeutics, studies should evaluate the drug product administered via the clinical route. Species selection should ideally consider relevance of the model with regard to the endpoints of interest, pharmacological responsiveness, and continuity with the nonclinical development program. 3) Evaluation of potential effects in the core battery (cardiovascular, central nervous, and respiratory systems) is recommended. In general: a. In vitro human ether-a-go-go-related gene (hERG) testing does not provide any specific value and is not warranted. b. Emphasis should be placed on in vivo evaluation of cardiovascular function, typically in nonhuman primates (NHPs). c. Due to the low level of concern, neurologic and respiratory function can be assessed concurrently with cardiovascular safety pharmacology evaluation in NHPs, within repeat-dose toxicity studies, or as stand-alone studies. In the latter case, rodents are most commonly used. 4) Other dedicated safety pharmacology studies, beyond the core battery, may have limited value for ONs. Although ONs can accumulate in the kidney and liver

  1. Template switching between PNA and RNA oligonucleotides (United States)

    Bohler, C.; Nielsen, P. E.; Orgel, L. E.; Miller, S. L. (Principal Investigator)


    The origin of the RNA world is not easily understood, as effective prebiotic syntheses of the components of RNA, the beta-ribofuranoside-5'-phosphates, are hard to envisage. Recognition of this difficulty has led to the proposal that other genetic systems, the components of which are more easily formed, may have preceded RNA. This raises the question of how transitions between one genetic system and another could occur. Peptide nucleic acid (PNA) resembles RNA in its ability to form double-helical complexes stabilized by Watson-Crick hydrogen bonding between adenine and thymine and between cytosine and guanine, but has a backbone that is held together by amide rather than by phosphodiester bonds. Oligonucleotides bases on RNA are known to act as templates that catalyse the non-enzymatic synthesis of their complements from activated mononucleotides, we now show that RNA oligonucleotides facilitate the synthesis of complementary PNA strands and vice versa. This suggests that a transition between different genetic systems can occur without loss of information.

  2. Effect of oligonucleotide primers in determining viral variability within hosts

    Directory of Open Access Journals (Sweden)

    Moya Andrés


    Full Text Available Abstract Background Genetic variability in viral populations is usually estimated by means of polymerase chain reaction (PCR based methods in which the relative abundance of each amplicon is assumed to be proportional to the frequency of the corresponding template in the initial sample. Although bias in template-to-product ratios has been described before, its relevance in describing viral genetic variability at the intrapatient level has not been fully assessed yet. Results To investigate the role of oligonucleotide design in estimating viral variability within hosts, genetic diversity in hepatitis C virus (HCV populations from eight infected patients was characterised by two parallel PCR amplifications performed with two slightly different sets of primers, followed by cloning and sequencing (mean = 89 cloned sequences per patient. Population genetics analyses of viral populations recovered by pairs of amplifications revealed that in seven patients statistically significant differences were detected between populations sampled with different set of primers. Conclusions Genetic variability analyses demonstrates that PCR selection due to the choice of primers, differing in their degeneracy degree at some nucleotide positions, can eclipse totally or partially viral variants, hence yielding significant different estimates of viral variability within a single patient and therefore eventually producing quite different qualitative and quantitative descriptions of viral populations within each host.

  3. Enhanced fluorescence of silver nanoclusters stabilized with branched oligonucleotides. (United States)

    Latorre, Alfonso; Lorca, Romina; Zamora, Félix; Somoza, Álvaro


    DNA stabilized silver nanoclusters (AgNCs) are promising optical materials, whose fluorescence properties can be tuned by the selection of the DNA sequence employed. In this work we have used modified oligonucleotides in the preparation of AgNCs. The fluorescent intensity obtained was 60 times higher than that achieved with standard oligonucleotides.

  4. Noncoding oligonucleotides: the belle of the ball in gene therapy. (United States)

    Shum, Ka-To; Rossi, John J


    Gene therapy carries the promise of cures for many diseases based on manipulating the expression of a person's genes toward the therapeutic goal. The relevance of noncoding oligonucleotides to human disease is attracting widespread attention. Noncoding oligonucleotides are not only involved in gene regulation, but can also be modified into therapeutic tools. There are many strategies that leverage noncoding oligonucleotides for gene therapy, including small interfering RNAs, antisense oligonucleotides, aptamers, ribozymes, decoys, and bacteriophage phi 29 RNAs. In this chapter, we will provide a broad, comprehensive overview of gene therapies that use noncoding oligonucleotides for disease treatment. The mechanism and development of each therapeutic will be described, with a particular focus on its clinical development. Finally, we will discuss the challenges associated with developing nucleic acid therapeutics and the prospects for future success.

  5. Predicting oligonucleotide-directed mutagenesis failures in protein engineering. (United States)

    Wassman, Christopher D; Tam, Phillip Y; Lathrop, Richard H; Weiss, Gregory A


    Protein engineering uses oligonucleotide-directed mutagenesis to modify DNA sequences through a two-step process of hybridization and enzymatic synthesis. Inefficient reactions confound attempts to introduce mutations, especially for the construction of vast combinatorial protein libraries. This paper applied computational approaches to the problem of inefficient mutagenesis. Several results implicated oligonucleotide annealing to non-target sites, termed 'cross-hybridization', as a significant contributor to mutagenesis reaction failures. Test oligonucleotides demonstrated control over reaction outcomes. A novel cross-hybridization score, quickly computable for any plasmid and oligonucleotide mixture, directly correlated with yields of deleterious mutagenesis side products. Cross-hybridization was confirmed conclusively by partial incorporation of an oligonucleotide at a predicted cross-hybridization site, and by modification of putative template secondary structure to control cross-hybridization. Even in low concentrations, cross-hybridizing species in mixtures poisoned reactions. These results provide a basis for improved mutagenesis efficiencies and increased diversities of cognate protein libraries.

  6. Conjugation of fluorescent proteins with DNA oligonucleotides. (United States)

    Lapiene, Vidmantas; Kukolka, Florian; Kiko, Kathrin; Arndt, Andreas; Niemeyer, Christof M


    This work describes the synthesis of covalent ssDNA conjugates of six fluorescent proteins, ECFP, EGFP, E(2)GFP, mDsRed, Dronpa, and mCherry, which were cloned with an accessible C-terminal cystein residue to enable site-selective coupling using a heterobispecific cross-linker. The resulting conjugates revealed similar fluorescence emission intensity to the unconjugated proteins, and the functionality of the tethered oligonucleotide was proven by specific Watson-Crick base pairing to cDNA-modified gold nanoparticles. Fluorescence spectroscopy analysis indicated that the fluorescence of the FP is quenched by the gold particle, and the extent of quenching varied with the intrinsic spectroscopic properties of FP as well as with the configuration of surface attachment. Since this study demonstrates that biological fluorophores can be selectively incorporated into and optically coupled with nanoparticle-based devices, applications in DNA-based nanofabrication can be foreseen.

  7. Preparation and application of triple helix forming oligonucleotides and single strand oligonucleotide donors for gene correction. (United States)

    Alam, Rowshon; Thazhathveetil, Arun Kalliat; Li, Hong; Seidman, Michael M


    Strategies for site-specific modulation of genomic sequences in mammalian cells require two components. One must be capable of recognizing and activating a specific target sequence in vivo, driving that site into an exploitable repair pathway. Information is transferred to the site via participation in the pathway by the second component, a donor nucleic acid, resulting in a permanent change in the target sequence. We have developed biologically active triple helix forming oligonucleotides (TFOs) as site-specific gene targeting reagents. These TFOs, linked to DNA reactive compounds (such as a cross-linking agent), activate pathways that can engage informational donors. We have used the combination of a psoralen-TFO and single strand oligonucleotide donors to generate novel cell lines with directed sequence changes at the target site. Here we describe the synthesis and purification of bioactive psoralen-linked TFOs, their co-introduction into mammalian cells with donor nucleic acids, and the identification of cells with sequence conversion of the target site. We have emphasized details in the synthesis and purification of the oligonucleotides that are essential for preparation of reagents with optimal activity.

  8. Detection and identification of intestinal pathogenic bacteria by hybridization to oligonucleotide microarrays

    Institute of Scientific and Technical Information of China (English)

    Lian-Qun Jin; Jun-Wen Li; Sheng-Qi Wang; Fu-Huan Chao; Xin-Wei Wang; Zheng-Quan Yuan


    AIM: To detect the common intestinal pathogenic bacteria quickly and accurately.METHODS: A rapid (<3 h) experimental procedure was set up based upon the gene chip technology. Target genes were amplified and hybridized by oligonucleotide microarrays.RESULTS: One hundred and seventy strains of bacteria in pure culture belonging to 11 genera were successfully discriminated under comparatively same conditions, and a series of specific hybridization maps corresponding to each kind of bacteria were obtained. When this method was applied to 26 divided cultures, 25 (96.2%) were identified.CONCLUSION: Salmonella sp., Escherichia coli, Shigella sp., Listeria monocytogenes, Vibrio parahaemolyticus,Staphylococcus aureus, Proteus sp., Bacillus cereus,Vibrio cholerae, Enterococcus faecalis, Yersinia enterocolitica, and Campylobacter jejuni can be detected and identified by our microarrays. The accuracy, range,and discrimination power of this assay can be continually improved by adding further oligonucleotides to the arrays without any significant increase of complexity or cost.

  9. Nucleic acid sequence detection using multiplexed oligonucleotide PCR (United States)

    Nolan, John P.; White, P. Scott


    Methods for rapidly detecting single or multiple sequence alleles in a sample nucleic acid are described. Provided are all of the oligonucleotide pairs capable of annealing specifically to a target allele and discriminating among possible sequences thereof, and ligating to each other to form an oligonucleotide complex when a particular sequence feature is present (or, alternatively, absent) in the sample nucleic acid. The design of each oligonucleotide pair permits the subsequent high-level PCR amplification of a specific amplicon when the oligonucleotide complex is formed, but not when the oligonucleotide complex is not formed. The presence or absence of the specific amplicon is used to detect the allele. Detection of the specific amplicon may be achieved using a variety of methods well known in the art, including without limitation, oligonucleotide capture onto DNA chips or microarrays, oligonucleotide capture onto beads or microspheres, electrophoresis, and mass spectrometry. Various labels and address-capture tags may be employed in the amplicon detection step of multiplexed assays, as further described herein.

  10. Design and analysis of mismatch probes for long oligonucleotide microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Ye; He, Zhili; Van Nostrand, Joy D.; Zhou, Jizhong


    Nonspecific hybridization is currently a major concern with microarray technology. One of most effective approaches to estimating nonspecific hybridizations in oligonucleotide microarrays is the utilization of mismatch probes; however, this approach has not been used for longer oligonucleotide probes. Here, an oligonucleotide microarray was constructed to evaluate and optimize parameters for 50-mer mismatch probe design. A perfect match (PM) and 28 mismatch (MM) probes were designed for each of ten target genes selected from three microorganisms. The microarrays were hybridized with synthesized complementary oligonucleotide targets at different temperatures (e.g., 42, 45 and 50 C). In general, the probes with evenly distributed mismatches were more distinguishable than those with randomly distributed mismatches. MM probes with 3, 4 and 5 mismatched nucleotides were differentiated for 50-mer oligonucleotide probes hybridized at 50, 45 and 42 C, respectively. Based on the experimental data generated from this study, a modified positional dependent nearest neighbor (MPDNN) model was constructed to adjust the thermodynamic parameters of matched and mismatched dimer nucleotides in the microarray environment. The MM probes with four flexible positional mismatches were designed using the newly established MPDNN model and the experimental results demonstrated that the redesigned MM probes could yield more consistent hybridizations. Conclusions: This study provides guidance on the design of MM probes for long oligonucleotides (e.g., 50 mers). The novel MPDNN model has improved the consistency for long MM probes, and this modeling method can potentially be used for the prediction of oligonucleotide microarray hybridizations.

  11. Antisense oligonucleotide induction of progerin in human myogenic cells.

    Directory of Open Access Journals (Sweden)

    Yue-Bei Luo

    Full Text Available We sought to use splice-switching antisense oligonucleotides to produce a model of accelerated ageing by enhancing expression of progerin, translated from a mis-spliced lamin A gene (LMNA transcript in human myogenic cells. The progerin transcript (LMNA Δ150 lacks the last 150 bases of exon 11, and is translated into a truncated protein associated with the severe premature ageing disease, Hutchinson-Gilford progeria syndrome (HGPS. HGPS arises from de novo mutations that activate a cryptic splice site in exon 11 of LMNA and result in progerin accumulation in tissues of mesodermal origin. Progerin has also been proposed to play a role in the 'natural' ageing process in tissues. We sought to test this hypothesis by producing a model of accelerated muscle ageing in human myogenic cells. A panel of splice-switching antisense oligonucleotides were designed to anneal across exon 11 of the LMNA pre-mRNA, and these compounds were transfected into primary human myogenic cells. RT-PCR showed that the majority of oligonucleotides were able to modify LMNA transcript processing. Oligonucleotides that annealed within the 150 base region of exon 11 that is missing in the progerin transcript, as well as those that targeted the normal exon 11 donor site induced the LMNA Δ150 transcript, but most oligonucleotides also generated variable levels of LMNA transcript missing the entire exon 11. Upon evaluation of different oligomer chemistries, the morpholino phosphorodiamidate oligonucleotides were found to be more efficient than the equivalent sequences prepared as oligonucleotides with 2'-O-methyl modified bases on a phosphorothioate backbone. The morpholino oligonucleotides induced nuclear localised progerin, demonstrated by immunostaining, and morphological nuclear changes typical of HGPS cells. We show that it is possible to induce progerin expression in myogenic cells using splice-switching oligonucleotides to redirect splicing of LMNA. This may offer a model

  12. Optical Characterization of Oligonucleotide DNA Influenced by Magnetic Fields

    Directory of Open Access Journals (Sweden)

    Seyedeh Maryam Banihashemian


    Full Text Available UV-VIS spectroscopic analysis of oligonucleotide DNA exposed to different magnetic fields was performed in order to investigate the relationship between DNA extinction coefficients and optical parameters according to magnetic-field strength. The results with the oligonucleotides adenine-thymine 100 mer (AT-100 DNA and cytosine-guanine 100 mer (CG-100 DNA indicate that the magnetic field influences DNA molar extinction coefficients and refractive indexes. The imaginary parts of the refractive index and molar extinction coefficients of the AT-100 and CG-100 DNA decreased after exposure to a magnetic field of 750 mT due to cleavage of the DNA oligonucleotides into smaller segments.

  13. Kinetic Hairpin Oligonucleotide Blockers for Selective Amplification of Rare Mutations (United States)

    Jia, Yanwei; Sanchez, J. Aquiles; Wangh, Lawrence J.


    Detection of rare mutant alleles in an excess of wild type alleles is increasingly important in cancer diagnosis. Several methods for selective amplification of a mutant allele via the polymerase chain reaction (PCR) have been reported, but each of these methods has its own limitations. A common problem is that Taq DNA polymerase errors early during amplification generate false positive mutations which also accumulate exponentially. In this paper, we described a novel method using hairpin oligonucleotide blockers that can selectively inhibit the amplification of wild type DNA during LATE-PCR amplification. LATE-PCR generates double-stranded DNA exponentially followed by linear amplification of single-stranded DNA. The efficiency of the blocker is optimized by adjusting the LATE-PCR temperature cycling profile. We also demonstrate that it is possible to minimize false positive signals caused by Taq DNA polymerase errors by using a mismatched excess primer plus a modified PCR profile to preferentially enrich for mutant target sequences prior to the start of the exponential phase of LATE-PCR amplification. In combination these procedures permit amplification of specific KRAS mutations in the presence of more than 10,000 fold excess of wild type DNA without false positive signals. PMID:25082368

  14. Oligonucleotide and Long Polymeric DNA Encoding

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E; Mariella Jr., R P; Christian, A T; Gardner, S N; Williams, J M


    This report summarizes the work done at Lawrence Livermore National Laboratory for the Oligonucleotide and Long Polymeric DNA Encoding project, part of the Microelectronic Bioprocesses Program at DARPA. The goal of the project was to develop a process by which long (circa 10,000 base-pair) synthetic DNA molecules could be synthesized in a timely and economic manner. During construction of the long molecule, errors in DNA sequence occur during hybridization and/or the subsequent enzymatic process. The work done on this project has resulted in a novel synthesis scheme that we call the parallel pyramid synthesis protocol, the development of a suit of computational tools to minimize and quantify errors in the synthesized DNA sequence, and experimental proof of this technique. The modeling consists of three interrelated modules: the bioinformatics code which determines the specifics of parallel pyramid synthesis for a given chain of long DNA, the thermodynamics code which tracks the products of DNA hybridization and polymerase extension during the later steps in the process, and the kinetics model which examines the temporal and spatial processes during one thermocycle. Most importantly, we conducted the first successful syntheses of a gene using small starting oligomers (tetramers). The synthesized sequence, 813 base pairs long, contained a 725 base pair gene, modified green fluorescent protein (mGFP), which has been shown to be a functional gene by cloning into cells and observing its green fluorescent product.

  15. Hole hopping rates in single strand oligonucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Borrelli, Raffaele [Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università di Torino, Largo Paolo Braccini 2, I-10095 Grugliasco, TO (Italy); Capobianco, Amedeo [Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, I-84084 Fisciano, SA (Italy); Peluso, Andrea, E-mail: [Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, I-84084 Fisciano, SA (Italy)


    Highlights: • DNA hole transfer rates have been computed. • Delocalized adenine domains significantly affect hole transfer rates in DNA. • Franck–Condon weighted density of state from DFT normal modes. • DNA application in molecular electronics. - Abstract: The rates of hole transfer between guanine and adenine in single strand DNA have been evaluated by using Fermi’s golden rule and Kubo’s generating function approach for the Franck–Condon weighted density of states. The whole sets of the normal modes and vibrational frequencies of the two nucleobases, obtained at DFT/B3LYP level of calculation, have been considered in computations. The results show that in single strand the pyramidalization/planarization mode of the amino groups of both nucleobases plays the major role. At room temperature, the Franck–Condon density of states extends over a wide range of hole site energy difference, 0–1 eV, giving some hints about the design of oligonucleotides of potential technological interest.

  16. Silver and Cyanine Staining of Oligonucleotides in Polyacrylamide Gel.

    Directory of Open Access Journals (Sweden)

    Weizhong Tang

    Full Text Available To explore why some oligonucleotides in denaturing polyacrylamide gel could not be silver-stained, 134 different oligonucleotides were analyzed using denaturing polyacrylamide gel electrophoresis stained with silver and asymmetric cyanine. As a result, we found that the sensitivity of oligos (dA, (dC, (dG and (dT to silver staining could be ranged as (dA > (dG > (dC > (dT from high to low. It was unexpected that oligo (dT was hard to be silver-stained. Moreover, the silver staining of an oligonucleotide containing base T could be partially or completely inhibited by base T. The inhibition of silver staining by base T was a competitive inhibition which could be affected by the amounts of the argyrophil nucleobase and base T, the cis-distance between the argyrophil nucleobase and base T, and the gel concentration. The changes of the intensity of an oligonucleotide band caused by the changes of DNA base composition were diverse and interesting. The intensity of some oligonucleotide bands would significantly change when the changes of DNA base composition accumulated to a certain extent (usually ≥ 4 nt. The sensitivity of cyanine staining of ≤ 11-nt long oligonucleotides could be enhanced about 250-fold by fixing the gels with methanol fixing solution.

  17. Carboranyl oligonucleotides. 3. Biochemical properties of oligonucleotides containing 5-(o-carboranyl-l-yl)-2{prime}-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Lesnikowski, Z.J.; Fulcrand, G.; Lloyd, R.M. Jr. [Veterans Affairs Medical Center and Georgia Research Center for AIDS and HIV Infections, Decatur, GA (United States)]|[Emory Univ. School of Medicine, Atlanta, GA (United States)


    Boronated oligonucleotides are potential candidates for boron neutron capture therapy, antisense technology, and as tools in molecular biology. The biological properties of dodecathymidylic acids containing one or more 5-(o-carboran-l-yl)-2{prime}-deoxyuridine residues at different locations within the oligonucleotide chain were studied. 5-(o-carboran-l-yl)-2{prime}-deoxyuridine containing oligonucleotides manifested marked increased lipophilicity and resistance to 3{prime}- or 5{prime}-phosphodiesterases compared to the corresponding unmodified oligomer. They were substrates for T4 polynucleotide kinase and primers for Escherichia coli polymerase I and human immunodeficiency virus type 1 reverse transcriptase but not for human DNA polymerase {alpha} and {beta}. They also formed heteroduplexes that were substrates for E. coli RNase H, an essential property for antisense technology. These studies indicate that the carboranyl-containing oligonucleotides have desirable properties that need to be exploited further in the design of novel biopharmaceuticals. 33 refs., 2 figs., 1 tab.

  18. Flare Plasma Iron Abundance (United States)

    Dennis, Brian R.; Dan, Chau; Jain, Rajmal; Schwartz, Richard A.; Tolbert, Anne K.


    The equivalent width of the iron-line complex at 6.7 keV seen in flare X-ray spectra suggests that the iron abundance of the hottest plasma at temperatures >approx.10 MK may sometimes be significantly lower than the nominal coronal abundance of four times the photospheric value that is commonly assumed. This conclusion is based on X-ray spectral observations of several flares seen in common with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Solar X-ray Spectrometer (SOXS) on the second Indian geostationary satellite, GSAT-2. The implications of this will be discussed as it relates to the origin of the hot flare plasma - either plasma already in the corona that is directly heated during the flare energy release process or chromospheric plasma that is heated by flare-accelerated particles and driven up into the corona. Other possible explanations of lower-than-expected equivalent widths of the iron-line complex will also be discussed.

  19. Targeting of single stranded oligonucleotides through metal-induced cyclization of short complementary strands : Targeting of single stranded oligonucleotides


    Freville, Fabrice; Richard, Tristan; Bathany, Katell; Moreau, Serge


    International audience; A new strategy to cyclize a short synthetic oligonucleotide on a DNA or a RNA target strand is described. This one relies on a metal-mediated cyclization of short synthetic oligonucleotides conjugated with two chelating 2,2':6',2”-terpyridine moieties at their 3' and 5' ends. Cyclization following metal addition (Zn2+, Fe2+) was demonstrated using UV monitored thermal denaturation experiments, mass spectrometry analysis and gel shift assays. NMR experiments were used t...

  20. Biominetic High Density Lipoproteins for the Delivery of Therapeutic Oligonucleotides (United States)

    Tripathy, Sushant

    Advances in nanotechnology have brought about novel inorganic and hybrid nanoparticles with unique physico-chemical properties that make them suitable for a broad range of applications---from nano-circuitry to drug delivery. A significant part of those advancements have led to ground-breaking discoveries that have changed the approaches to formulation of therapeutics against diseases, such as cancer. Now-a-days the focus does not lie solely on finding a candidate small-molecule therapeutic with minimal adverse effects, but researchers are looking up to nanoparticles to improve biodistribution and biocompatibility profile of clinically proven therapeutics. The plethora of conjugation chemistries offered by currently extant inorganic nanoparticles have, in recent years, led to great leaps in the field of biomimicry---a modality that promises high biocompatibility. Further, in the pursuit of highly specific therapeutic molecules, researchers have turned to silencing oligonucleotides and some have already brought together the strengths of nanoparticles and silencing oligonucleotides in search of an efficacious therapy for cancer with minimal adverse effects. This dissertation work focuses on such a biomimetic platform---a gold nanoparticle based high density lipoprotein biomimetic (HDL NP), for the delivery of therapeutic oligonucleotides. The first chapter of this body of work introduces the molecular target of the silencing oligonucleotides---VEGFR2, and its role in the progression of solid tumor cancers. The background information also covers important aspects of natural high density lipoproteins (HDL), especially their innate capacity to bind and deliver exogenous and endogenous silencing oligonucleotides to tissues that express their high affinity receptor SRB1. We subsequently describe the synthesis of the biomimetic HDL NP and its oligonucleotide conjugates, and establish their biocompatibility. Further on, experimental data demonstrate the efficacy of silencing

  1. An anchored framework BAC map of mouse chromosome 11 assembled using multiplex oligonucleotide hybridization. (United States)

    Cai, W W; Reneker, J; Chow, C W; Vaishnav, M; Bradley, A


    Despite abundant library resources for many organisms, physical mapping of these organisms has been seriously limited due to lack of efficient library screening techniques. We have developed a highly efficient strategy for large-scale screening of genomic libraries based on multiplex oligonucleotide hybridization on high-density genomic filters. We have applied this strategy to generate a bacterial artificial chromosome (BAC) anchored map of mouse chromosome 11. Using the MIT mouse SSLP data, 320 pairs of oligonucleotide probes were designed with an "overgo" computer program that selects new primer sequences that avoid the microsatellite repeat. BACs identified by these probes are automatically anchored to the chromosome. Ninety-two percent of the probes identified positive clones from a 5.9-fold coverage mouse BAC library with an average of 7 positive clones per marker. An average of 4.2 clones was confirmed for 204 markers by PCR. Our data show that a large number of clones can be efficiently isolated from a large genomic library using this strategy with minimal effort. This strategy will have wide application for large-scale mapping and sequencing of human and other large genomes.

  2. Correction of a Cystic Fibrosis Splicing Mutation by Antisense Oligonucleotides. (United States)

    Igreja, Susana; Clarke, Luka A; Botelho, Hugo M; Marques, Luís; Amaral, Margarida D


    Cystic fibrosis (CF), the most common life-threatening genetic disease in Caucasians, is caused by ∼2,000 different mutations in the CF transmembrane conductance regulator (CFTR) gene. A significant fraction of these (∼13%) affect pre-mRNA splicing for which novel therapies have been somewhat neglected. We have previously described the effect of the CFTR splicing mutation c.2657+5G>A in IVS16, showing that it originates transcripts lacking exon 16 as well as wild-type transcripts. Here, we tested an RNA-based antisense oligonucleotide (AON) strategy to correct the aberrant splicing caused by this mutation. Two AONs (AON1/2) complementary to the pre-mRNA IVS16 mutant region were designed and their effect on splicing was assessed at the RNA and protein levels, on intracellular protein localization and function. To this end, we used the 2657+5G>A mutant CFTR minigene stably expressed in HEK293 Flp-In cells that express a single copy of the transgene. RNA data from AON1-treated mutant cells show that exon 16 inclusion was almost completely restored (to 95%), also resulting in increased levels of correctly localized CFTR protein at the plasma membrane (PM) and with increased function. A novel two-color CFTR splicing reporter minigene developed here allowed the quantitative monitoring of splicing by automated microscopy localization of CFTR at the PM. The AON strategy is thus a promising therapeutic approach for the specific correction of alternative splicing.

  3. Investigations of oligonucleotide usage variance within and between prokaryotes

    DEFF Research Database (Denmark)

    Bohlin, J.; Skjerve, E.; Ussery, David


    Oligonucleotide usage in archaeal and bacterial genomes can be linked to a number of properties, including codon usage (trinucleotides), DNA base-stacking energy (dinucleotides), and DNA structural conformation (di-to tetranucleotides). We wanted to assess the statistical information potential...... was that prokaryotic chromosomes can be described by hexanucleotide frequencies, suggesting that prokaryotic DNA is predominantly short range correlated, i. e., information in prokaryotic genomes is encoded in short oligonucleotides. Oligonucleotide usage varied more within AT-rich and host-associated genomes than...... in GC-rich and free-living genomes, and this variation was mainly located in non-coding regions. Bias (selectional pressure) in tetranucleotide usage correlated with GC content, and coding regions were more biased than non-coding regions. Non-coding regions were also found to be approximately 5.5% more...

  4. Delivery of RNAi-Based Oligonucleotides by Electropermeabilization

    Directory of Open Access Journals (Sweden)

    Muriel Golzio


    Full Text Available For more than a decade, understanding of RNA interference (RNAi has been a growing field of interest. The potent gene silencing ability that small oligonucleotides have offers new perspectives for cancer therapeutics. One of the present limits is that many biological barriers exist for their efficient delivery into target cells or tissues. Electropermeabilization (EP is one of the physical methods successfully used to transfer small oligonucleotides into cells or tissues. EP consists in the direct application of calibrated electric pulses to cells or tissues that transiently permeabilize the plasma membranes, allowing efficient in vitro and in vivo. cytoplasmic delivery of exogenous molecules. The present review reports on the type of therapeutic RNAi-based oligonucleotides that can be electrotransferred, the mechanism(s of their electrotransfer and the technical settings for pre-clinical purposes.

  5. Rapid and accurate synthesis of TALE genes from synthetic oligonucleotides. (United States)

    Wang, Fenghua; Zhang, Hefei; Gao, Jingxia; Chen, Fengjiao; Chen, Sijie; Zhang, Cuizhen; Peng, Gang


    Custom synthesis of transcription activator-like effector (TALE) genes has relied upon plasmid libraries of pre-fabricated TALE-repeat monomers or oligomers. Here we describe a novel synthesis method that directly incorporates annealed synthetic oligonucleotides into the TALE-repeat units. Our approach utilizes iterative sets of oligonucleotides and a translational frame check strategy to ensure the high efficiency and accuracy of TALE-gene synthesis. TALE arrays of more than 20 repeats can be constructed, and the majority of the synthesized constructs have perfect sequences. In addition, this novel oligonucleotide-based method can readily accommodate design changes to the TALE repeats. We demonstrated an increased gene targeting efficiency against a genomic site containing a potentially methylated cytosine by incorporating non-conventional repeat variable di-residue (RVD) sequences.

  6. A novel catechol-based universal support for oligonucleotide synthesis. (United States)

    Anderson, Keith M; Jaquinod, Laurent; Jensen, Michael A; Ngo, Nam; Davis, Ronald W


    A novel universal support for deoxyribo- and ribonucleic acid synthesis has been developed. The support, constructed from 1,4-dimethoxycatechol, represents an improvement over existing universal supports because of its ability to cleave and deprotect under mild conditions in standard reagents. Because no nonvolatile additives are required for cleavage and deprotection, the synthesized oligonucleotides do not require purification prior to use in biochemical assays. Using reverse phase HPLC and electrospray mass spectroscopy, it was determined that oligonucleotides synthesized on the universal support (UL1) 3'-dephosphorylate quickly (9 h in 28-30% ammonium hydroxide (NH4OH) at 55 degrees C, 2 h in 28-30% NH4OH at 80 degrees C, or <1 h in ammonium hydroxide/methylamine (1:1) (AMA) at 80 degrees C). Oligonucleotides used as primers for the polymerase chain reaction (PCR) assay were found to perform identically to control primers, demonstrating full biological compatibility. In addition, a method was developed for sintering the universal support directly into a filter plug which can be pressure fit into the synthesis column of a commercial synthesizer. The universal support plugs allow the synthesis of high-quality oligonucleotides at least 120 nucleotides in length, with purity comparable to non-universal commercial supports and approximately 50% lower reagent consumption. The universal support plugs are routinely used to synthesize deoxyribo-, ribo-, 3'-modified, 5'-modified, and thioated oligonucleotides. The flexibility of the universal support and the efficiency of 3'-dephosphorylation are expected to increase the use of universal supports in oligonucleotide synthesis.

  7. Synthesis of Peptide-Oligonucleotide Conjugates Using a Heterobifunctional Crosslinker (United States)

    Williams, Berea A.R.; Chaput, John C.


    Peptide-oligonucleotide conjugates (POCs) are molecular chimeras composed of a nucleic acid moiety covalently attached to a polypeptide moiety. POCs have been used in numerous applications from therapeutics to nanotechnology, and most recently as combinatorial agents in the assembly of bivalent protein affinity reagents. This unit describes the synthesis and purification of POC molecules using the heterobifunctional crosslinking reagent succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC), which enables amine-modified oligonucleotides to become covalently linked to cysteine-modified polypeptides. This solution-based protocol consists of a two-step synthesis followed by a single purification step. PMID:20827717

  8. Chemical phosphorylation of deoxyribonucleosides and thermolytic DNA oligonucleotides. (United States)

    Ausín, Cristina; Grajkowski, Andrzej; Cieślak, Jacek; Beaucage, Serge L


    The phosphorylating reagent bis[S-(4,4'-dimethoxytrityl)-2-mercaptoethyl]-N,N-diisopropylphosphoramidite is prepared in three steps from commercial methyl thioglycolate and diisopropylphosphoramidous dichloride. The phosphorylating reagent has been used successfully in the solid-phase synthesis of deoxyribonucleoside 5'-/3'-phosphate or -thiophosphate monoesters and oligonucleotide 5'-phosphate/-thiophosphate monoesters. Bis[S-(4,4'-dimethoxytrityl)-2-mercaptoethyl]-N,N-diisopropylphosphoramidite has also been employed in the construction of a thermolytic dinucleotide prodrug model to evaluate the ability of the reagent to produce thermosentive oligonucleotide prodrugs under mild temperature conditions ( approximately 25 degrees C) for potential therapeutic applications.

  9. Versatile functionalization of nanoelectrodes by oligonucleotides via pyrrole electrochemistry. (United States)

    Descamps, Emeline; Nguyen, Khoa; Bouchain-Gautier, Christelle; Filoramo, Arianna; Goux-Capes, Laurence; Goffman, Marcello; Bourgoin, Jean-Philippe; Mailley, Pascal; Livache, Thierry


    Surface modification at the nanometer scale is a challenge for the future of molecular electronics. In particular, the precise anchoring and electrical addressing of biological scaffolds such as complex DNA nanonetworks is of importance for generating bio-directed assemblies of nano-objects for nanocircuit purposes. Herein, we consider the individual modification of nanoelectrodes with different oligonucleotide sequences by an electrochemically driven co-polymerization process of pyrrole and modified oligonucleotide sequences bearing pyrrole monomers. We demonstrate that this one-step technique presents the advantages of simplicity, localization of surface modification, mechanical, biological and chemical stability of the coatings, and high lateral resolution.

  10. Raccoon abundance inventory report (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the results of a raccoon abundance inventory on Clarence Cannon National Wildlife Refuge in 2012. Determining raccoon abundance allows for...

  11. Climate and local abundance in freshwater fishes


    Knouft, Jason H.; Anthony, Melissa M.


    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide va...

  12. Oligonucleotide-directed mutagenesis for precision gene editing. (United States)

    Sauer, Noel J; Mozoruk, Jerry; Miller, Ryan B; Warburg, Zachary J; Walker, Keith A; Beetham, Peter R; Schöpke, Christian R; Gocal, Greg F W


    Differences in gene sequences, many of which are single nucleotide polymorphisms, underlie some of the most important traits in plants. With humanity facing significant challenges to increase global agricultural productivity, there is an urgent need to accelerate the development of these traits in plants. oligonucleotide-directed mutagenesis (ODM), one of the many tools of Cibus' Rapid Trait Development System (RTDS(™) ) technology, offers a rapid, precise and non-transgenic breeding alternative for trait improvement in agriculture to address this urgent need. This review explores the application of ODM as a precision genome editing technology, with emphasis on using oligonucleotides to make targeted edits in plasmid, episomal and chromosomal DNA of bacterial, fungal, mammalian and plant systems. The process of employing ODM by way of RTDS technology has been improved in many ways by utilizing a fluorescence conversion system wherein a blue fluorescent protein (BFP) can be changed to a green fluorescent protein (GFP) by editing a single nucleotide of the BFP gene (CAC→TAC; H66 to Y66). For example, dependent on oligonucleotide length, applying oligonucleotide-mediated technology to target the BFP transgene in Arabidopsis thaliana protoplasts resulted in up to 0.05% precisely edited GFP loci. Here, the development of traits in commercially relevant plant varieties to improve crop performance by genome editing technologies such as ODM, and by extension RTDS, is reviewed.

  13. Lipid-modified G4-decoy oligonucleotide anchored to nanoparticles

    DEFF Research Database (Denmark)

    Cogoi, S; Jakobsen, U; Pedersen, E B


    KRAS is mutated in >90% of pancreatic ductal adenocarcinomas. As its inactivation leads to tumour regression, mutant KRAS is considered an attractive target for anticancer drugs. In this study we report a new delivery strategy for a G4-decoy oligonucleotide that sequesters MAZ, a transcription fa...

  14. Regioselective immobilization of short oligonucleotides to acrylic copolymer gels. (United States)

    Timofeev, E; Kochetkova, S V; Mirzabekov, A D; Florentiev, V L


    Four types of polyacrylamide or polydimethyl-acrylamide gels for regioselective (by immobilization at the 3' end) of short oligonucleotides have been designed for use in manufacturing oligonucleotide microchips. Two of these supports contain amino or aldehyde groups in the gel, allowing coupling with oligonucleotides bearing aldehyde or amino groups, respectively, in the presence of a reducing agent. The aldehyde gel support showed a higher immobilization efficiency relative to the amino gel. Of all reducing agents tested, the best results were obtained with a pyridine-borane complex. The other supports are based on an acrylamide gel activated with glutaraldehyde or a hydroxyalkyl-functionalized gel treated with mesyl chloride. The use of dimethylacrylamide instead of acrylamide allows subsequent gel modifications in organic solvents. All the immobilization methods are easy and simple to perform, give high and reproducible yields, allow long durations of storage of the activated support, and provide high stability of attachment and low non-specific binding. Although these gel supports have been developed for preparing oligonucleotide microchips, they may be used for other purposes as well. PMID:8774893

  15. LNA 5'-phosphoramidites for 5'→3'-oligonucleotide synthesis

    DEFF Research Database (Denmark)

    Madsen, Andreas Stahl; Kumar, Santhosh T.; Wengel, Jesper


    Hereby we report an efficient synthesis of LNA thymine and LNA 5-methylcytosine 5′-phosphoramidites, allowing incorporation of LNA thymine and LNA 5-methylcytosine into oligonucleotides synthesized in the 5′→3′ direction. Key steps include regioselective enzymatic benzoylation of the 5′-hydroxy g...

  16. Systematic design of mouse Vh gene family-specific oligonucleotides

    NARCIS (Netherlands)

    Seijen, AM; Seijen, HG; Bos, NA


    Kabat's database has often been used to design mouse Vh gene-specific 5 ' primers. The emphasis was mostly on constructing a universal (degenerate) 5 ' primer or 5 ' primer set, which would be able to match every mouse Vh gene. We were interested in finding oligonucleotides that could be used as pri

  17. Chromosome-specific painting in Cucumis species using bulked oligonucleotides (United States)

    Chromosome-specific painting is a powerful technique in molecular cytogenetic and genome research. We developed an oligonucleotide (oligo)-based chromosome painting technique in cucumber (Cucumis sativus) that will be applicable in any plant species with a sequenced genome. Oligos specific to a sing...

  18. Oligonucleotides with 1,4-dioxane-based nucleotide monomers

    DEFF Research Database (Denmark)

    Madsen, Andreas S; Wengel, Jesper


    An epimeric mixture of H-phosphonates 5R and 5S has been synthesized in three steps from known secouridine 1. Separation of the epimers has been accomplished by RP-HPLC, allowing full characterization and incorporation of monomers X and Y into 9-mer oligonucleotides using H-phosphonates building ...

  19. Analysis of oligonucleotide array experiments with repeated measures using mixed models

    Directory of Open Access Journals (Sweden)

    Getchell Thomas V


    Full Text Available Abstract Background Two or more factor mixed factorial experiments are becoming increasingly common in microarray data analysis. In this case study, the two factors are presence (Patients with Alzheimer's disease or absence (Control of the disease, and brain regions including olfactory bulb (OB or cerebellum (CER. In the design considered in this manuscript, OB and CER are repeated measurements from the same subject and, hence, are correlated. It is critical to identify sources of variability in the analysis of oligonucleotide array experiments with repeated measures and correlations among data points have to be considered. In addition, multiple testing problems are more complicated in experiments with multi-level treatments or treatment combinations. Results In this study we adopted a linear mixed model to analyze oligonucleotide array experiments with repeated measures. We first construct a generalized F test to select differentially expressed genes. The Benjamini and Hochberg (BH procedure of controlling false discovery rate (FDR at 5% was applied to the P values of the generalized F test. For those genes with significant generalized F test, we then categorize them based on whether the interaction terms were significant or not at the α-level (αnew = 0.0033 determined by the FDR procedure. Since simple effects may be examined for the genes with significant interaction effect, we adopt the protected Fisher's least significant difference test (LSD procedure at the level of αnew to control the family-wise error rate (FWER for each gene examined. Conclusions A linear mixed model is appropriate for analysis of oligonucleotide array experiments with repeated measures. We constructed a generalized F test to select differentially expressed genes, and then applied a specific sequence of tests to identify factorial effects. This sequence of tests applied was designed to control for gene based FWER.

  20. Effects of fluid flow on the oligonucleotide folding in single-walled carbon nanotubes. (United States)

    Lim, M C G; Zhong, Z W


    This paper presents molecular-dynamics (MD) simulations of DNA oligonucleotide and water molecules translocating through carbon nanotube (CNT) channels. An induced pressure difference is applied to the system by pushing a layer of water molecules toward the flow direction to drive the oligonucleotide and other molecules. This MD simulation investigates the changes that occur in the conformation of the oligonucleotide due to water molecules in nanochannels while controlling the temperature and volume of the system in a canonical ensemble. The results show that the oligonucleotide in the (8,8)-(12,12) CNT channel forms a folded state at a lower pressure, whereas the oligonucleotide in the (10,10)-(14,14) CNT channel forms a folded state at a higher pressure instead. The van der Waals forces between the water molecules and the oligonucleotide suggest that the attraction between these two types of molecules results in the linear arrangements of the bases of the oligonucleotide. For a larger nanotube channel, the folding of the oligonucleotide is mainly dependent on the solvent (water molecules), whereas pressure, the size of the nanotube junction, and water molecules are the considering factors of the folding of the oligonucleotide at a smaller nanotube channel. For a folded oligonucleotide, the water distribution around the oligonucleotide is concentrated at a smaller range than that for the distribution around an unfolded oligonucleotide.

  1. Glycoclusters on oligonucleotide and PNA scaffolds: synthesis and applications. (United States)

    Spinelli, Nicolas; Defrancq, Eric; Morvan, François


    Conjugation of oligonucleotides (ONs) to a variety of reporter groups has been the subject of intensive research during the last decade. Conjugation is indeed of great interest because it can be used not only to improve the existing ONs properties but also to impart new ones. In this context tremendous efforts have been made to conjugate carbohydrate moieties to ONs. Indeed carbohydrates play an important role in biological processes such as signal transduction and cell adhesion through the recognition with sugar-binding proteins (i.e. lectins) located on the surface of cells. For this reason, carbohydrate-oligonucleotide conjugates (COCs) have been first developed for improving the poor cellular uptake or tissue specific delivery of ONs through receptor-mediated endocytosis. Besides the targeted ONs delivery, carbohydrate-oligonucleotide conjugates (COCs) are also evaluated in the context of carbohydrate biochips in which surface coating with carbohydrates is achieved by using the DNA-directed immobilization strategy (DDI). Peptide nucleic acids (PNAs) have also been extensively investigated as a surrogate of DNA for diverse applications. Therefore attachment of carbohydrate moieties to this class of molecules has been studied. The aforementioned applications of COCs require mimicking of the natural processes, in which the weak individual protein-carbohydrate binding is overcome by using multivalent interactions. This tutorial review focuses on the recent advances in carbohydrate-oligonucleotide conjugates and describes the major synthetic approaches available. In addition, an overview of applications that have been developed using various scaffolds allowing multivalent interactions is provided. Finally recent results on the use of peptide nucleic acids as oligonucleotides surrogate are described.

  2. Biophysical and RNA Interference Inhibitory Properties of Oligonucleotides Carrying Tetrathiafulvalene Groups at Terminal Positions

    Directory of Open Access Journals (Sweden)

    Sónia Pérez-Rentero


    Full Text Available Oligonucleotide conjugates carrying a single functionalized tetrathiafulvalene (TTF unit linked through a threoninol molecule to the 3′ or 5′ ends were synthesized together with their complementary oligonucleotides carrying a TTF, pyrene, or pentafluorophenyl group. TTF-oligonucleotide conjugates formed duplexes with higher thermal stability than the corresponding unmodified oligonucleotides and pyrene- and pentafluorophenyl-modified oligonucleotides. TTF-modified oligonucleotides are able to bind to citrate-stabilized gold nanoparticles (AuNPs and produce stable gold AuNPs functionalized with oligonucleotides. Finally, TTF-oligoribonucleotides have been synthesized to produce siRNA duplexes carrying TTF units. The presence of the TTF molecule is compatible with the RNA interference mechanism for gene inhibition.

  3. Precision Chemical Abundance Measurements

    DEFF Research Database (Denmark)

    Yong, David; Grundahl, Frank; Meléndez, Jorge;


    This talk covers preliminary work in which we apply a strictly differential line-by-line chemical abundance analysis to high quality UVES spectra of the globular cluster NGC 6752. We achieve extremely high precision in the measurement of relative abundance ratios. Our results indicate that the ob......This talk covers preliminary work in which we apply a strictly differential line-by-line chemical abundance analysis to high quality UVES spectra of the globular cluster NGC 6752. We achieve extremely high precision in the measurement of relative abundance ratios. Our results indicate...... that the observed abundance dispersion exceeds the measurement uncertainties and that many pairs of elements show significant correlations when plotting [X1/H] vs. [X2/H]. Our tentative conclusions are that either NGC 6752 is not chemically homogeneous at the ~=0.03 dex level or the abundance variations...

  4. Typing of enteroviruses by use of microwell oligonucleotide arrays. (United States)

    Susi, P; Hattara, L; Waris, M; Luoma-Aho, T; Siitari, H; Hyypiä, T; Saviranta, P


    We have developed a straightforward assay for the rapid typing of enteroviruses using oligonucleotide arrays in microtiter wells. The viral nucleic acids are concomitantly amplified and labeled during reverse transcription-PCR, and unpurified PCR products are used for hybridization. DNA strands are separated by alkaline denaturation, and hybridization is started by neutralization. The microarray hybridization reactions and the subsequent washes are performed in standard 96-well microtiter plates, which makes the method easily adaptable to high-throughput analysis. We describe here the assay principle and its potential in clinical laboratory use by correctly identifying 10 different enterovirus reference strains. Furthermore, we explore the detection of unknown sequence variants using serotype consensus oligonucleotide probes. With just two consensus probes for the coxsackievirus A9 (CVA9) serotype, we detected 23 out of 25 highly diverse CVA9 isolates. Overall, the assay involves several features aiming at ease of performance, robustness, and applicability to large-scale studies.

  5. Solid-phase synthesis of siRNA oligonucleotides. (United States)

    Beaucage, Serge L


    Since the discovery of RNA interference (RNAi) as a means to silence the expression of specific genes, small interfering RNA (siRNA) oligonucleotides have been recognized as powerful tools for targeting therapeutically important mRNAs and eliciting their destruction. This discovery has created a high demand for synthetic oligoribonucleotides as potential therapeutics and has spurred a renaissance in the development of rapid, efficient methods for solid-phase RNA synthesis. The design and implementation of 2'-hydroxyl protecting groups that provide ribonucleoside phosphoramidites with coupling kinetics and coupling efficiencies comparable to those of deoxyribonucleoside phosphoramidites are key to the production of RNA oligonucleotides in sufficient quantity and purity for pharmaceutical applications. In this context, various siRNAs were chemically modified to identify the biophysical and biochemical parameters necessary for effective and stable RNAi-mediated gene-silencing activities.

  6. Electrochemical uranyl cation biosensor with DNA oligonucleotides as receptor layer. (United States)

    Jarczewska, Marta; Ziółkowski, Robert; Górski, Łukasz; Malinowska, Elżbieta


    The present study aims at the further development of the uranyl oligonucleotide-based voltammetric biosensor, which takes advantage of strong interaction between UO2(2+) and phosphate DNA backbone. Herein we report the optimization of working parameters of previously elaborated electrochemical DNA biosensor. It is shown that the sensor sensitivity is highly dependent on the oligonucleotide probe length and the incubation time of sensor in a sample solution. Consequently, the highest sensitivity was obtained for 10-nucleotide sequence and 60 min incubation time. The lower detection limit towards uranyl cation for developed biosensor was 30 nM. The influence of mixed monolayers and the possibility of developing a non-calibration device were also investigated. The selectivity of the proposed biosensor was significantly improved via elimination of adenine nucleobases from the DNA probe. Moreover, the regeneration procedure was elaborated and tested to prolong the use of the same biosensor for 4 subsequent determinations of UO2(2+).

  7. Palladium-Catalyzed Modification of Unprotected Nucleosides, Nucleotides, and Oligonucleotides

    Directory of Open Access Journals (Sweden)

    Kevin H. Shaughnessy


    Full Text Available Synthetic modification of nucleoside structures provides access to molecules of interest as pharmaceuticals, biochemical probes, and models to study diseases. Covalent modification of the purine and pyrimidine bases is an important strategy for the synthesis of these adducts. Palladium-catalyzed cross-coupling is a powerful method to attach groups to the base heterocycles through the formation of new carbon-carbon and carbon-heteroatom bonds. In this review, approaches to palladium-catalyzed modification of unprotected nucleosides, nucleotides, and oligonucleotides are reviewed. Polar reaction media, such as water or polar aprotic solvents, allow reactions to be performed directly on the hydrophilic nucleosides and nucleotides without the need to use protecting groups. Homogeneous aqueous-phase coupling reactions catalyzed by palladium complexes of water-soluble ligands provide a general approach to the synthesis of modified nucleosides, nucleotides, and oligonucleotides.

  8. One-oligonucleotide method for constructing vectors for RNA interference

    Institute of Scientific and Technical Information of China (English)



    Aim: To develop an easy, fast, automated, and inexpensive method for constructing short-hairpin-RNA cassettes for RNAi studies. Methods: Using single oligonucleotides, a variety of DNA cassettes for RNAi vectors were constructed in only few minutes in an automated manner. The cassettes, targeting the eGFP,were cloned into plasmids driven by RNA polymerase Ⅲ promoter H 1. Then, the plasmids were transfected into HeLa cells that were later infected with a recombinant adenovirus encoding the eGFP gene. The level of eGFP fluorescence was evaluated by confocal imaging and flow cytometry. Results: The plasmids constructed with the DNA cassettes made by the one-oligonucleotide method inhibited eGFP with different potencies, ranging from 55% to 75%. Conclusion: By using the method reported here, it is possible to simultaneously construct hundreds of different DNA cassettes for RNAi experiments in an inexpensive, automated way. This method will facilitate functional genomics studies on mammalian cells.

  9. Fluorescence quenching of TMR by guanosine in oligonucleotides

    Institute of Scientific and Technical Information of China (English)


    Nucleotide-specific fluorescence quenching in fluorescently labeled DNA has many applications in biotechnology. We have studied the inter-and intra-molecular quenching of tetramethylrhodamine (TMR) by nucleotides to better understand their quenching mechanism and influencing factors. In agreement with previous work, dGMP can effectively quench TMR, while the quenching of TMR by other nucleotides is negligible. The Stern-Volmer plot between TMR and dGMP delivers a bimolecular quenching constant of Ks=52.3 M-1. The fluorescence of TMR in labeled oligonucleotides decreases efficiently through photoinduced electron transfer by guanosine. The quenching rate constant between TMR and guanosine was measured using fluorescence correlation spectroscopy (FCS). In addition, our data show that the steric hindrance by bases around guanosine has significant effect on the G-quenching. The availability of these data should be useful in designing fluorescent oligonucleotides and understanding the G-quenching process.

  10. Voltammetric behaviour of oligonucleotide lipoplexes adsorbed onto glassy carbon electrodes


    Piedade, J. A. P.; M. Mano; Lima, M. C. Pedroso de; Oretskaya, T S; Oliveira-Brett, A. M.


    The voltammetric behaviour of oligonucleotide lipoplexes (ODN-lipoplexes) prepared from short oligodeoxynucleotides (ODN), with different base compositions, and liposomes of the cationic lipid DOTAP, was studied by differential pulse voltammetry with a glassy carbon mini-electrode. It was found that the ODN base composition influences the ODN-lipoplex voltammetric response. Differential pulse voltammograms for ODN-lipoplexes of the ODN adenosine nucleotides present two different features when...

  11. Anti-tumor activity of splice-switching oligonucleotides


    Bauman, John A; Li, Shyh-Dar; Yang, Angela; Huang, Leaf; Kole, Ryszard


    Alternative splicing has emerged as an important target for molecular therapies. Splice-switching oligonucleotides (SSOs) modulate alternative splicing by hybridizing to pre-mRNA sequences involved in splicing and blocking access to the transcript by splicing factors. Recently, the efficacy of SSOs has been established in various animal disease models; however, the application of SSOs against cancer targets has been hindered by poor in vivo delivery of antisense therapeutics to tumor cells. T...

  12. Sex determination of bovine preimplantation embryos by oligonucleotide microarray. (United States)

    Yang, Hua; Zhong, Fagang; Yang, Yonglin; Wang, Xinhua; Liu, Shouren; Zhu, Bin


    The aim has been to set up a rapid and accurate microarray assay using sandwich mode for sex determination of bovine preimplantation embryos. Twelve sequence-specific oligonucleotide capture probes used to discriminate 12 samples were spotted onto the aldehyde-modified glass slides by Arrayer. The 2 recognition probes used to identify coding regions of the sex-determining region of the Y chromosome gene (SRY) and β-casein (CSN2) reference gene were coupled with biotin. The assay was optimized by using genomic DNA extracted from blood samples of known sex individuals. Polymerase chain reaction (PCR) was used to amplify the fragments in the HMG box region of SRY gene and CSN2 gene with sequence-specific primers. The sex of samples was identified by detecting both the SRY and CSN2 genes simultaneously in 2 reaction cells of microarrays, with the male having SRY and CSN2 signals and the female only CSN2. The sex of 20 bovine preimplantation embryos was determined by oligonucleotide microarray. The protocol was run with a blind test that showed a 100% (82/82) specificity and accuracy in sexing of leukocytes. The bovine embryos were transferred into 20 bovine recipients, with a pregnant rate of 40% (8/20). Three calves were born at term, and 5 fetuses were miscarried. Their sexes were fully in accordance with the embryonic sex predetermination predicted by oligonucleotide microarray. This suggests that the oligonucleotide microarray method of SRY gene analysis can be used in early sex prediction of bovine embryos in breeding programs.

  13. Thermoplastic polymers surfaces for Dip-Pen Nanolithography of oligonucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Suriano, Raffaella [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Biella, Serena, E-mail: [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Cesura, Federico; Levi, Marinella; Turri, Stefano [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)


    Different thermoplastic polymers were spin-coated to prepare smooth surfaces for the direct deposition of end-group modified oligonucleotides by Dip-Pen Nanolithography. A study of the diffusion process was done in order to investigate the dependence of calibration coefficient and quality of deposited features on environmental parameters (temperature, relative humidity) and ink's molecular weight and functionality. The optimization of the process parameters led to the realization of high quality and density nanoarrays on plastics.

  14. Anti-fouling characteristics of surface-confined oligonucleotide strands bioconjugated on streptavidin platforms in the presence of nanomaterials. (United States)

    Mir, Mònica; Cameron, Petra J; Zhong, Xinhua; Azzaroni, Omar; Alvarez, Marta; Knoll, Wolfgang


    This work describes our studies on the molecular design of interfacial architectures suitable for DNA sensing which could resist non-specific binding of nanomaterials commonly used as labels for amplifying biorecognition events. We observed that the non-specific binding of bio-nanomaterials to surface-confined oligonucleotide strands is highly dependent on the characteristics of the interfacial architecture. Thiolated double stranded oligonucleotide arrays assembled on Au surfaces evidence significant fouling in the presence of nanoparticles (NPs) at the nanomolar level. The non-specific interaction between the oligonucleotide strands and the nanomaterials can be sensitively minimized by introducing streptavidin (SAv) as an underlayer conjugated to the DNA arrays. The role of the SAv layer was attributed to the significant hydrophilic repulsion between the SAv-modified surface and the nanomaterials in close proximity to the interface, thus conferring outstanding anti-fouling characteristics to the interfacial architecture. These results provide a simple and straightforward strategy to overcome the limitations introduced by the non-specific binding of labels to achieve reliable detection of DNA-based biorecognition events.

  15. Particle-Based Microarrays of Oligonucleotides and Oligopeptides. (United States)

    Nesterov-Mueller, Alexander; Maerkle, Frieder; Hahn, Lothar; Foertsch, Tobias; Schillo, Sebastian; Bykovskaya, Valentina; Sedlmayr, Martyna; Weber, Laura K; Ridder, Barbara; Soehindrijo, Miriam; Muenster, Bastian; Striffler, Jakob; Bischoff, F Ralf; Breitling, Frank; Loeffler, Felix F


    In this review, we describe different methods of microarray fabrication based on the use of micro-particles/-beads and point out future tendencies in the development of particle-based arrays. First, we consider oligonucleotide bead arrays, where each bead is a carrier of one specific sequence of oligonucleotides. This bead-based array approach, appearing in the late 1990s, enabled high-throughput oligonucleotide analysis and had a large impact on genome research. Furthermore, we consider particle-based peptide array fabrication using combinatorial chemistry. In this approach, particles can directly participate in both the synthesis and the transfer of synthesized combinatorial molecules to a substrate. Subsequently, we describe in more detail the synthesis of peptide arrays with amino acid polymer particles, which imbed the amino acids inside their polymer matrix. By heating these particles, the polymer matrix is transformed into a highly viscous gel, and thereby, imbedded monomers are allowed to participate in the coupling reaction. Finally, we focus on combinatorial laser fusing of particles for the synthesis of high-density peptide arrays. This method combines the advantages of particles and combinatorial lithographic approaches.

  16. Particle-Based Microarrays of Oligonucleotides and Oligopeptides

    Directory of Open Access Journals (Sweden)

    Alexander Nesterov-Mueller


    Full Text Available In this review, we describe different methods of microarray fabrication based on the use of micro-particles/-beads and point out future tendencies in the development of particle-based arrays. First, we consider oligonucleotide bead arrays, where each bead is a carrier of one specific sequence of oligonucleotides. This bead-based array approach, appearing in the late 1990s, enabled high-throughput oligonucleotide analysis and had a large impact on genome research. Furthermore, we consider particle-based peptide array fabrication using combinatorial chemistry. In this approach, particles can directly participate in both the synthesis and the transfer of synthesized combinatorial molecules to a substrate. Subsequently, we describe in more detail the synthesis of peptide arrays with amino acid polymer particles, which imbed the amino acids inside their polymer matrix. By heating these particles, the polymer matrix is transformed into a highly viscous gel, and thereby, imbedded monomers are allowed to participate in the coupling reaction. Finally, we focus on combinatorial laser fusing of particles for the synthesis of high-density peptide arrays. This method combines the advantages of particles and combinatorial lithographic approaches.

  17. Characterization of self-assembled DNA concatemers from synthetic oligonucleotides

    Directory of Open Access Journals (Sweden)

    Lu Sun


    Full Text Available Studies of DNA–ligand interaction on a single molecule level provide opportunities to understand individual behavior of molecules. Construction of DNA molecules with repetitive copies of the same segments of sequences linked in series could be helpful for enhancing the interaction possibility for sequence-specific binding ligand to DNA. Here we report on the use of synthetic oligonucleotides to self-assembly into duplex DNA concatemeric molecules. Two strands of synthetic oligonucleotides used here were designed with 50-mer in length and the sequences are semi-complimentary so to hybridize spontaneously into concatemers of double stranded DNA. In order to optimize the length of the concatemers the oligonucleotides were incubated at different oligomer concentrations, ionic strengths and temperatures for different durations. Increasing the salt concentration to 200 mM NaCl was found to be the major optimizing factor because at this enhanced ionic strength the concatemers formed most quickly and the other parameters had no detectable effect. The size and shape of formed DNA concatemers were studied by gel electrophoresis in agarose, polyacrylamide gels and by AFM. Our results show that linear DNA constructs up to several hundred base pairs were formed and could be separated from a substantial fraction of non-linear constructs.

  18. Targeting several CAG expansion diseases by a single antisense oligonucleotide.

    Directory of Open Access Journals (Sweden)

    Melvin M Evers

    Full Text Available To date there are 9 known diseases caused by an expanded polyglutamine repeat, with the most prevalent being Huntington's disease. Huntington's disease is a progressive autosomal dominant neurodegenerative disorder for which currently no therapy is available. It is caused by a CAG repeat expansion in the HTT gene, which results in an expansion of a glutamine stretch at the N-terminal end of the huntingtin protein. This polyglutamine expansion plays a central role in the disease and results in the accumulation of cytoplasmic and nuclear aggregates. Here, we make use of modified 2'-O-methyl phosphorothioate (CUGn triplet-repeat antisense oligonucleotides to effectively reduce mutant huntingtin transcript and protein levels in patient-derived Huntington's disease fibroblasts and lymphoblasts. The most effective antisense oligonucleotide, (CUG(7, also reduced mutant ataxin-1 and ataxin-3 mRNA levels in spinocerebellar ataxia 1 and 3, respectively, and atrophin-1 in dentatorubral-pallidoluysian atrophy patient derived fibroblasts. This antisense oligonucleotide is not only a promising therapeutic tool to reduce mutant huntingtin levels in Huntington's disease but our results in spinocerebellar ataxia and dentatorubral-pallidoluysian atrophy cells suggest that this could also be applicable to other polyglutamine expansion disorders as well.


    Directory of Open Access Journals (Sweden)

    Pedro Miguel Duarte Moreno


    Full Text Available Under clinical development since the early 90’s and with two successfully approved drugs (Fomivirsen and Mipomersen, oligonucleotide-based therapeutics have not yet delivered a clinical drug to the market in the cancer field. Whilst many pre-clinical data has been generated, a lack of understanding still exists on how to efficiently tackle all the different challenges presented for cancer targeting in a clinical setting. Namely, effective drug vectorization, careful choice of target gene or synergistic multi-gene targeting are surely decisive, while caution must be exerted to avoid potential toxic, often misleading off-target-effects. Here a brief overview will be given on the nucleic acid chemistry advances that established oligonucleotide technologies as a promising therapeutic alternative and ongoing cancer related clinical trials. Special attention will be given towards a perspective on the hurdles encountered specifically in the cancer field by this class of therapeutic oligonucleotides and a view on possible avenues for success is presented, with particular focus on the contribution from nanotechnology to the field.

  20. Recursive construction of perfect DNA molecules from imperfect oligonucleotides. (United States)

    Linshiz, Gregory; Yehezkel, Tuval Ben; Kaplan, Shai; Gronau, Ilan; Ravid, Sivan; Adar, Rivka; Shapiro, Ehud


    Making faultless complex objects from potentially faulty building blocks is a fundamental challenge in computer engineering, nanotechnology and synthetic biology. Here, we show for the first time how recursion can be used to address this challenge and demonstrate a recursive procedure that constructs error-free DNA molecules and their libraries from error-prone oligonucleotides. Divide and Conquer (D&C), the quintessential recursive problem-solving technique, is applied in silico to divide the target DNA sequence into overlapping oligonucleotides short enough to be synthesized directly, albeit with errors; error-prone oligonucleotides are recursively combined in vitro, forming error-prone DNA molecules; error-free fragments of these molecules are then identified, extracted and used as new, typically longer and more accurate, inputs to another iteration of the recursive construction procedure; the entire process repeats until an error-free target molecule is formed. Our recursive construction procedure surpasses existing methods for de novo DNA synthesis in speed, precision, amenability to automation, ease of combining synthetic and natural DNA fragments, and ability to construct designer DNA libraries. It thus provides a novel and robust foundation for the design and construction of synthetic biological molecules and organisms.

  1. Hf Transition Probabilities and Abundances

    CERN Document Server

    Lawler, J E; Labby, Z E; Sneden, C; Cowan, J J; Ivans, I I


    Radiative lifetimes from laser-induced fluorescence measurements, accurate to about +/- 5 percent, are reported for 41 odd-parity levels of Hf II. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 150 lines of Hf II. Approximately half of these new transition probabilities overlap with recent independent measurements using a similar approach. The two sets of measurements are found to be in good agreement for measurements in common. Our new laboratory data are applied to refine the hafnium photospheric solar abundance and to determine hafnium abundances in 10 metal-poor giant stars with enhanced r-process abundances. For the Sun we derive log epsilon (Hf) = 0.88 +/- 0.08 from four lines; the uncertainty is dominated by the weakness of the lines and their blending by other spectral features. Within the uncertainties of our analysis, the r-process-rich stars possess constant Hf/La and Hf/Eu abundance ratios, log epsilon (Hf...

  2. Synthesis of triazole-linked oligonucleotides with high affinity to DNA complements and an analysis of their compatibility with biosystems. (United States)

    Varizhuk, Anna M; Kaluzhny, Dmitry N; Novikov, Roman A; Chizhov, Alexandr O; Smirnov, Igor P; Chuvilin, Andrey N; Tatarinova, Olga N; Fisunov, Gleb Y; Pozmogova, Galina E; Florentiev, Vladimir L


    New oligonucleotide analogues with triazole internucleotide linkages were synthesized, and their hybridization properties were studied. The analogues demonstrated DNA binding affinities similar to those of unmodified oligonucleotides. The modification was shown to protect the oligonucleotides from nuclease hydrolysis. The modified oligonucleotides were tested as PCR primers. Modifications remote from the 3'-terminus were tolerated by polymerases. Our results suggest that these new oligonucleotide analogues are among the most promising triazole DNA mimics characterized to date.

  3. Development of specific fluorescent oligonucleotide probes for in situ identification of wine lactic acid bacteria. (United States)

    Blasco, Lucía; Ferrer, Sergi; Pardo, Isabel


    A rapid method for the identification of lactic acid bacteria (LAB) from wine has been developed. This method is based on fluorescence in situ hybridisation (FISH), using fluorescent oligonucleotide probes, homologous to 16S rDNA of those species of LAB commonly found in wines. The protocol for the specific detection of these bacteria was established through the hybridisation of 36 reference strains. The specificity of the probes was evaluated by using pure cultures. Probes were used to identify species in different wines, making it evident that direct identification and quantification from natural samples without culturing is also possible. The results show that FISH is a promising technique for the rapid identification of LAB, allowing positive identification in a few hours (4-16 h).

  4. Testing the feasibility of DNA typing for human identification by PCR and an oligonucleotide ligation assay

    Energy Technology Data Exchange (ETDEWEB)

    Delahunty, C.; Ankener, W.; Deng, Qiang [Univ. of Washington, Seattle, WA (United States)] [and others


    The use of DNA typing in human genome analysis is increasing and finding widespread application in the area of forensic and paternity testing. In this report, we explore the feasibility of typing single nucleotide polymorphisms (SNPs) by using a semiautomated method for analyzing human DNA samples. In this approach, PCR is used to amplify segments of human DNA containing a common SNP. Allelic nucleotides in the amplified product are then typed by a calorimetric implementation of the oligonucleotide ligation assay (OLA). The results of the combined assay, PCR/OLA, are read directly by a spectrophotometer; the absorbances are compiled and the genotypes are automatically determined. A panel of 20 markers has been developed for DNA typing and has been tested using a sample panel from the CEPH pedigrees (CEPH parents). The results of this typing, as well as the potential to apply this method to larger populations, are discussed. 62 refs., 2 figs., 4 tabs.

  5. Discrimination of oligonucleotides of different lengths with a wild-type aerolysin nanopore (United States)

    Cao, Chan; Ying, Yi-Lun; Hu, Zheng-Li; Liao, Dong-Fang; Tian, He; Long, Yi-Tao


    Protein nanopores offer an inexpensive, label-free method of analysing single oligonucleotides. The sensitivity of the approach is largely determined by the characteristics of the pore-forming protein employed, and typically relies on nanopores that have been chemically modified or incorporate molecular motors. Effective, high-resolution discrimination of oligonucleotides using wild-type biological nanopores remains difficult to achieve. Here, we show that a wild-type aerolysin nanopore can resolve individual short oligonucleotides that are 2 to 10 bases long. The sensing capabilities are attributed to the geometry of aerolysin and the electrostatic interactions between the nanopore and the oligonucleotides. We also show that the wild-type aerolysin nanopores can distinguish individual oligonucleotides from mixtures and can monitor the stepwise cleavage of oligonucleotides by exonuclease I.

  6. Synthesis of triazole-nucleoside phosphoramidites and their use in solid-phase oligonucleotide synthesis. (United States)

    Peel, Brandon J; Efthymiou, Tim C; Desaulniers, Jean-Paul


    Triazole-backbone oligonucleotides are macromolecules that have one or more triazole units that are acting as a backbone mimic. Triazoles within the backbone have been used within oligonucleotides for a variety of applications. This unit describes the preparation and synthesis of two triazole-nucleoside phosphoramidites [uracil-triazole-uracil (UtU) and cytosine-triazole-uracil (CtU)] based on a PNA-like scaffold, and their incorporation within oligonucleotides.

  7. Hemopoiesis-stimulating activity of immobilized oligonucleotides and hyaluronidase during cytostatic-induced myelosuppression. (United States)

    Dygai, A M; Skurikhin, E G; Pershina, O V; Zhdanov, V V; Khmelevskaya, A M; Andreeva, T V; Poponina, A M; Zjuzkov, G N; Udut, E V; Khrichkova, T Ju; Simanina, E V; Miroshnichenko, L A; Stavrova, L A; Tchaikovsky, A S; Markova, T S; Gurto, R V; Brjushinina, O S; Slepichev, V A


    The hemopoiesis-stimulating effect of combined treatment with immobilized oligonucleotides and hyaluronidase preparations was studied during cytostatic-induced myelosuppression caused by cyclophosphamide administration. Immobilized hyaluronidase was shown to increase the efficiency of correction of changes in the erythroid and granulocytic hemopoietic stems with immobilized oligonucleotides. This potentiation of the effect of immobilized oligonucleotides by immobilized hyaluronidase was related to an increase in functional activity of committed hemopoietic precursors.

  8. A New Achiral Linker Reagent for the Incorporation of Multiple Amino Groups Into Oligonucleotides

    DEFF Research Database (Denmark)


    The present invention relates to a new functionalized achiral linker reagent for incorporating multiple primary amino groups or reporter groups into oligonucleotides following the phosphoramidite methodology. It is possible to substitute any ribodeoxynucleotide, deoxynucleotide, or nucleotide wit......, to a method for preparing a labelled oligonucleotide, and to the use of the labelled oligonucleotide as hybridisation probe, in polymerase chain reactions (PCR), in nucleic acid sequencing, in cloning recombinant DNA and $i(in vitro) mutagenesis....


    Energy Technology Data Exchange (ETDEWEB)

    Luck, R. E.; Andrievsky, S. M. [Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States); Korotin, S. N.; Kovtyukh, V. V., E-mail:, E-mail:, E-mail:, E-mail: [Department of Astronomy and Astronomical Observatory, Odessa National University, Isaac Newton Institute of Chile, Odessa Branch, Shevchenko Park, 65014 Odessa (Ukraine)


    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  10. Label-free detection of hybridization of oligonucleotides by oblique-incidence reflectivity difference method

    Institute of Scientific and Technical Information of China (English)


    The microarrays of 20-base oligonucleotide with different concentrations are detected before and after hybridization by the oblique-incidence reflectivity difference (OI-RD) method. The experimental results prove that OI-RD is a label-free method which can not only distinguish the concentration difference of oligonucleotides before and after the hybridization but also detect the hybridization of short oligonucleotides. At present the OI-RD method can detect 0.39 μmol/L 20-base oligonucleotide or less. These results suggest that the OI-RD method is a promising and potential technique for label-free detection of biological microarrays.

  11. Efficient assembly of very short oligonucleotides using T4 DNA Ligase

    Directory of Open Access Journals (Sweden)

    Holt Robert A


    Full Text Available Abstract Background In principle, a pre-constructed library of all possible short oligonucleotides could be used to construct many distinct gene sequences. In order to assess the feasibility of such an approach, we characterized T4 DNA Ligase activity on short oligonucleotide substrates and defined conditions suitable for assembly of a plurality of oligonucleotides. Findings Ligation by T4 DNA Ligase was found to be dependent on the formation of a double stranded DNA duplex of at least five base pairs surrounding the site of ligation. However, ligations could be performed effectively with overhangs smaller than five base pairs and oligonucleotides as small as octamers, in the presence of a second, complementary oligonucleotide. We demonstrate the feasibility of simultaneous oligonucleotide phosphorylation and ligation and, as a proof of principle for DNA synthesis through the assembly of short oligonucleotides, we performed a hierarchical ligation procedure whereby octamers were combined to construct a target 128-bp segment of the beta-actin gene. Conclusions Oligonucleotides as short as 8 nucleotides can be efficiently assembled using T4 DNA Ligase. Thus, the construction of synthetic genes, without the need for custom oligonucleotide synthesis, appears feasible.

  12. Splice-switching antisense oligonucleotides as therapeutic drugs


    Havens, Mallory A.; Hastings, Michelle L.


    Splice-switching oligonucleotides (SSOs) are short, synthetic, antisense, modified nucleic acids that base-pair with a pre-mRNA and disrupt the normal splicing repertoire of the transcript by blocking the RNA–RNA base-pairing or protein–RNA binding interactions that occur between components of the splicing machinery and the pre-mRNA. Splicing of pre-mRNA is required for the proper expression of the vast majority of protein-coding genes, and thus, targeting the process offers a means to manipu...

  13. Chemically modified oligonucleotides with efficient RNase H response

    DEFF Research Database (Denmark)

    Vester, Birte; Boel, Anne Marie; Lobedanz, Sune;


    Ten different chemically modified nucleosides were incorporated into short DNA strands (chimeric oligonucleotides ON3-ON12 and ON15-ON24) and then tested for their capacity to mediate RNAse H cleavage of the complementary RNA strand. The modifications were placed at two central positions directly...... in the RNase H cleaving region. The RNA strand of duplexes with ON3, ON5 and ON12 were cleaved more efficiently than the RNA strand of the DNA:RNA control duplex. There seems to be no correlation between the thermal stability between the duplexes and RNase H cleavage....

  14. Climate and local abundance in freshwater fishes. (United States)

    Knouft, Jason H; Anthony, Melissa M


    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa.

  15. A new oligonucleotide microarray for detection of pathogenic and non-pathogenic Legionella spp. (United States)

    Cao, Boyang; Liu, Xiangqian; Yu, Xiang; Chen, Min; Feng, Lu; Wang, Lei


    Legionella pneumophila has been recognized as the major cause of legionellosis since the discovery of the deadly disease. Legionella spp. other than L. pneumophila were later found to be responsible to many non-pneumophila infections. The non-L. pneumophila infections are likely under-detected because of a lack of effective diagnosis. In this report, we have sequenced the 16S-23S rRNA gene internal transcribed spacer (ITS) of 10 Legionella species and subspecies, including L. anisa, L. bozemanii, L. dumoffii, L. fairfieldensis, L. gormanii, L. jordanis, L. maceachernii, L. micdadei, L. pneumophila subspp. fraseri and L. pneumophila subspp. pasculleii, and developed a rapid oligonucleotide microarray detection technique accordingly to identify 12 most common Legionella spp., which consist of 11 pathogenic species of L. anisa, L. bozemanii, L. dumoffii, L. gormanii, L. jordanis, L. longbeachae, L. maceachernii, L. micdadei, and L. pneumophila (including subspp. pneumophila, subspp. fraseri, and subspp. pasculleii) and one non-pathogenic species, L. fairfieldensis. Twenty-nine probes that reproducibly detected multiple Legionella species with high specificity were included in the array. A total of 52 strains, including 30 target pathogens and 22 non-target bacteria, were used to verify the oligonucleotide microarray assay. The sensitivity of the detection was at 1.0 ng with genomic DNA or 13 CFU/100 mL with Legionella cultures. The microarray detected seven samples of air conditioner-condensed water with 100% accuracy, validating the technique as a promising method for applications in basic microbiology, clinical diagnosis, food safety, and epidemiological surveillance. The phylogenetic study based on the ITS has also revealed that the non-pathogenic L. fairfieldensis is the closest to L. pneumophila than the nine other pathogenic Legionella spp.

  16. A comparison of alternative 60-mer probe designs in an in-situ synthesized oligonucleotide microarray

    Directory of Open Access Journals (Sweden)

    Fairbanks Benjamin D


    Full Text Available Abstract Background DNA microarrays have proven powerful for functional genomics studies. Several technologies exist for the generation of whole-genome arrays. It is well documented that 25mer probes directed against different regions of the same gene produce variable signal intensity values. However, the extent to which this is true for probes of greater length (60mers is not well characterized. Moreover, this information has not previously been reported for whole-genome arrays designed against bacteria, whose genomes may differ substantially in characteristics directly affecting microarray performance. Results We report here an analysis of alternative 60mer probe designs for an in-situ synthesized oligonucleotide array for the GC rich, β-proteobacterium Burkholderia cenocepacia. Probes were designed using the ArrayOligoSel3.5 software package and whole-genome microarrays synthesized by Agilent, Inc. using their in-situ, ink-jet technology platform. We first validated the quality of the microarrays as demonstrated by an average signal to noise ratio of >1000. Next, we determined that the variance of replicate probes (1178 total probes examined of identical sequence was 3.8% whereas the variance of alternative probes (558 total alternative probes examined designs was 9.5%. We determined that depending upon the definition, about 2.4% of replicate and 7.8% of alternative probes produced outlier conclusions. Finally, we determined none of the probe design subscores (GC content, internal repeat, binding energy and self annealment produced by ArrayOligoSel3.5 were predictive or probes that produced outlier signals. Conclusion Our analysis demonstrated that the use of multiple probes per target sequence is not essential for in-situ synthesized 60mer oligonucleotide arrays designed against bacteria. Although probes producing outlier signals were identified, the use of ratios results in less than 10% of such outlier conclusions. We also determined that

  17. The use of oligonucleotide probes for meningococcal serotype characterization

    Directory of Open Access Journals (Sweden)

    SACCHI Claudio Tavares


    Full Text Available In the present study we examine the potential use of oligonucleotide probes to characterize Neisseria meningitidis serotypes without the use of monoclonal antibodies (MAbs. Antigenic diversity on PorB protein forms the bases of serotyping method. However, the current panel of MAbs underestimated, by at least 50% the PorB variability, presumably because reagents for several PorB variable regions (VRs are lacking, or because a number of VR variants are not recognized by serotype-defining MAbs12. We analyzed the use of oligonucleotide probes to characterize serotype 10 and serotype 19 of N. meningitidis. The porB gene sequence for the prototype strain of serotype 10 was determined, aligned with 7 other porB sequences from different serotypes, and analysis of individual VRs were performed. The results of DNA probes 21U (VR1-A and 615U (VR3-B used against 72 N. meningitidis strains confirm that VR1 type A and VR3 type B encode epitopes for serotype-defined MAbs 19 and 10, respectively. The use of probes for characterizing serotypes possible can type 100% of the PorB VR diversity. It is a simple and rapid method specially useful for analysis of large number of samples.

  18. Serial incorporation of a monovalent GalNAc phosphoramidite unit into hepatocyte-targeting antisense oligonucleotides. (United States)

    Yamamoto, Tsuyoshi; Sawamura, Motoki; Wada, Fumito; Harada-Shiba, Mariko; Obika, Satoshi


    The targeting of abundant hepatic asialoglycoprotein receptors (ASGPR) with trivalent N-acetylgalactosamine (GalNAc) is a reliable strategy for efficiently delivering antisense oligonucleotides (ASOs) to the liver. We here experimentally demonstrate the high systemic potential of the synthetically-accessible, phosphodiester-linked monovalent GalNAc unit when tethered to the 5'-terminus of well-characterised 2',4'-bridged nucleic acid (also known as locked nucleic acid)-modified apolipoprotein B-targeting ASO via a bio-labile linker. Quantitative analysis of the hepatic disposition of the ASOs revealed that phosphodiester is preferable to phosphorothioate as an interunit linkage in terms of ASGPR binding of the GalNAc moiety, as well as the subcellular behavior of the ASO. The flexibility of this monomeric unit was demonstrated by attaching up to 5 GalNAc units in a serial manner and showing that knockdown activity improves as the number of GalNAc units increases. Our study suggests the structural requirements for efficient hepatocellular targeting using monovalent GalNAc and could contribute to a new molecular design for suitably modifying ASO.

  19. Dominant microbial composition and its vertical distribution in saline meromictic Lake Kaiike (Japan) as revealed by quantitative oligonucleotide probe membrane hybridization. (United States)

    Koizumi, Yoshikazu; Kojima, Hisaya; Fukui, Manabu


    Vertical distributions of dominant bacterial populations in saline meromictic Lake Kaiike were investigated throughout the water column and sediment by quantitative oligonucleotide probe membrane hybridization. Three oligonucleotide probes specific for the small-subunit (SSU) rRNA of three groups of Chlorobiaceae were newly designed. In addition, three general domain (Bacteria, Archaea, and Eukarya)-specific probes, two delta-Proteobacteria-specific probes, a Chlorobiaceae-specific probe, and a Chloroflexi-specific probe were used after optimization of their washing conditions. The abundance of the sum of SSU rRNAs hybridizing with probes specific for three groups of Chlorobiaceae relative to total SSU rRNA peaked in the chemocline, accounting for up to 68%. The abundance of the delta-proteobacterial SSU rRNA relative to total SSU rRNA rapidly increased just below the chemocline up to 29% in anoxic water and peaked at the 2- to 3-cm sediment depth at ca. 34%. The abundance of SSU rRNAs hybridizing with the probe specific for the phylum Chloroflexi relative to total SSU rRNA was highest (31 to 54%) in the top of the sediment but then steeply declined with depth and became stable at 11 to 19%, indicating the robust coexistence of sulfate-reducing bacteria and Chloroflexi in the top of the sediment. Any SSU rRNA of Chloroflexi in the water column was under the detection limit. The summation of the signals of group-specific probes used in this study accounted for up to 89% of total SSU rRNA, suggesting that the DGGE-oligonucleotide probe hybridization approach, in contrast to conventional culture-dependent approaches, was very effective in covering dominant populations.

  20. Deuterium abundance and cosmology

    CERN Document Server

    Vidal-Madjar, A; Lemoine, M


    We review the status of the measurements of the deuterium abundance from the local interstellar medium to the solar system and high redshifts absorbers toward quasars. We present preliminary results toward a white dwarf and a QSO. We conclude that the deuterium evolution from the Big-Bang to now is still not properly understood.

  1. Studies on the Syntheses and Properties of 5'-Branched-sugar Isonucleosides and the Related Oligonucleotides

    Institute of Scientific and Technical Information of China (English)

    Tian Xiaobing; Zhang Lihe; Min Jimei


    @@ The chemistry of nucleosides and oligonucleotides is an actively investigated field in the search for new drugs. Thesyntheses and the properties of isonucleosides and oligonucleotides have been investigated to improve their stability,antitumor and antiviral activities, and to reduce their toxicity.

  2. The MOX/SUC precursor strategies: robust ways to construct functionalized oligonucleotides. (United States)

    Polushin, N


    The use of phosphoramidites bearing one or more methoxyoxalamido (MOX) or succinimido (SUC) reactive groups for construction of functionalized oligonucleotides is described. The efficiency of the new precursor strategy was demonstrated in the synthesis of oligonucleotide containing up to 16 imidazole residues.

  3. Detection of oligonucleotide hybridization on a single microparticle by time-resolved fluorometry: hybridization assays on polymer particles obtained by direct solid phase assembly of the oligonucleotide probes. (United States)

    Hakala, H; Heinonen, P; Iitiä, A; Lönnberg, H


    Oligodeoxyribonucleotides were assembled by conventional phosphoramidite chemistry on uniformly sized (50 microns) porous glycidyl methacrylate/ethylene dimethacrylate (SINTEF) and compact polystyrene (Dynosphere) particles, the aminoalkyl side chains of which were further derivatized with DMTrO-acetyl groups. The linker was completely resistant toward ammonolytic deprotection of the base moieties. The quality of oligonucleotides was assessed by repeating the synthesis on the same particles derivatized with a cleavable ester linker. The ability of the oligonucleotide-coated particles to bind complementary sequences via hybridization was examined by following the attachment of oligonucleotides bearing a photoluminescent europium(III) chelate to the particles. The fluorescence emission was measured directly on a single particle. The effects of the following factors on the kinetics and efficiency of hybridization were studied: number of particles in a given volume of the assay solution, loading of oligonucleotide on the particle, concentration of the target oligonucleotide in solution, length of the hybridizing sequence, presence of noncomplementary sequences, and ionic strength. The fluorescence signal measured on a single particle after hybridization was observed to be proportional to the concentration of the target oligonucleotide in solution over a concentration range of 5 orders of magnitude.

  4. Affinity hydrogels for controlled protein release using nucleic acid aptamers and complementary oligonucleotides. (United States)

    Soontornworajit, Boonchoy; Zhou, Jing; Snipes, Matthew P; Battig, Mark R; Wang, Yong


    Biomaterials for the precise control of protein release are important to the development of new strategies for treating human diseases. This study aimed to fundamentally understand aptamer--protein dissociation triggered by complementary oligonucleotides, and to apply this understanding to develop affinity hydrogels for controlled protein release. The results showed that the oligonucleotide tails of the aptamers played a critical role in inducing intermolecular hybridization and triggering aptamer--protein dissociation. In addition, the attachment of the oligonucleotide tails to the aptamers and the increase of hybridizing length could produce a synergistic effect on the dissociation of bound proteins from their aptamers. More importantly, pegylated complementary oligonucleotides could successfully trigger protein release from the aptamer-functionalized hydrogels at multiple time points. Based on these results, it is believed that aptamer-functionalized hydrogels and complementary oligonucleotides hold great potential of controlling the release of protein drugs to treat human diseases.

  5. Design of oligonucleotides for microarrays and perspectives for design of multi-transcriptome arrays

    DEFF Research Database (Denmark)

    Nielsen, Henrik Bjørn; Wernersson, Rasmus; Knudsen, Steen


    with an overview of these parameters. We present here a flexible tool named OligoWiz for designing oligonucleotides for multiple purposes. OligoWiz presents a set of parameter scores in a graphical interface to facilitate an overview for the user. Additional custom parameter scores can easily be added......Optimal design of oligonucleotides for microarrays involves tedious and laborious work evaluating potential oligonucleotides relative to a series of parameters. The currently available tools for this purpose are limited in their flexibility and do not present the oligonucleotide designer...... to the program to extend the default parameters: homology, DeltaTm, low-complexity, position and GATC-only. Furthermore we present an analysis of the limitations in designing oligonucleotide sets that can detect transcripts from multiple organisms. OligoWiz is available at

  6. A review of statistical methods for preprocessing oligonucleotide microarrays. (United States)

    Wu, Zhijin


    Microarrays have become an indispensable tool in biomedical research. This powerful technology not only makes it possible to quantify a large number of nucleic acid molecules simultaneously, but also produces data with many sources of noise. A number of preprocessing steps are therefore necessary to convert the raw data, usually in the form of hybridisation images, to measures of biological meaning that can be used in further statistical analysis. Preprocessing of oligonucleotide arrays includes image processing, background adjustment, data normalisation/transformation and sometimes summarisation when multiple probes are used to target one genomic unit. In this article, we review the issues encountered in each preprocessing step and introduce the statistical models and methods in preprocessing.

  7. Antisense oligonucleotide targeting midkine suppresses in vivo angiogenesis

    Institute of Scientific and Technical Information of China (English)

    Li-Cheng Dai; Xiang Wang; Xing Yao; Yong-Liang Lu; Jin-Liang Ping; Jian-Fang He


    AIM: To evaluate the effect of antisense oligonucleotide targeting midkine (MK-AS) on angiogenesis in chick chorioallantoic membrane (CAM) andin situ human hepatocellular carcinoma (HCC).METHODS: An in situ human hepatocellular carcinoma (HCC) model and CAM assay were used in this experiment. The effect of MK-AS on angiogenesis was evaluated by cell proliferation assay and hematoxylineosin (HE) staining.RESULTS: MK-AS significantly inhibited human umbilical vein endothelial cells (HUVEC) and in situ human HCC growth. At the same time, MK-AS suppressed the angiogenesis both in human hepatocellular carcinoma cell line (HEPG2)-induced CAM and in situ human HCC tissues.CONCLUSION: MK-AS is an effective antiangiogenesis agent in vivo.

  8. Empirical evaluation of oligonucleotide probe selection for DNA microarrays.

    Directory of Open Access Journals (Sweden)

    Jennifer G Mulle

    Full Text Available DNA-based microarrays are increasingly central to biomedical research. Selecting oligonucleotide sequences that will behave consistently across experiments is essential to the design, production and performance of DNA microarrays. Here our aim was to improve on probe design parameters by empirically and systematically evaluating probe performance in a multivariate context. We used experimental data from 19 array CGH hybridizations to assess the probe performance of 385,474 probes tiled in the Duchenne muscular dystrophy (DMD region of the X chromosome. Our results demonstrate that probe melting temperature, single nucleotide polymorphisms (SNPs, and homocytosine motifs all have a strong effect on probe behavior. These findings, when incorporated into future microarray probe selection algorithms, may improve microarray performance for a wide variety of applications.

  9. Empirical evaluation of oligonucleotide probe selection for DNA microarrays. (United States)

    Mulle, Jennifer G; Patel, Viren C; Warren, Stephen T; Hegde, Madhuri R; Cutler, David J; Zwick, Michael E


    DNA-based microarrays are increasingly central to biomedical research. Selecting oligonucleotide sequences that will behave consistently across experiments is essential to the design, production and performance of DNA microarrays. Here our aim was to improve on probe design parameters by empirically and systematically evaluating probe performance in a multivariate context. We used experimental data from 19 array CGH hybridizations to assess the probe performance of 385,474 probes tiled in the Duchenne muscular dystrophy (DMD) region of the X chromosome. Our results demonstrate that probe melting temperature, single nucleotide polymorphisms (SNPs), and homocytosine motifs all have a strong effect on probe behavior. These findings, when incorporated into future microarray probe selection algorithms, may improve microarray performance for a wide variety of applications.

  10. Direct microcontact printing of oligonucleotides for biochip applications

    Directory of Open Access Journals (Sweden)

    Trévisiol E


    Full Text Available Abstract Background A critical step in the fabrication of biochips is the controlled placement of probes molecules on solid surfaces. This is currently performed by sequential deposition of probes on a target surface with split or solid pins. In this article, we present a cost-effective procedure namely microcontact printing using stamps, for a parallel deposition of probes applicable for manufacturing biochips. Results Contrary to a previous work, we showed that the stamps tailored with an elastomeric poly(dimethylsiloxane material did not require any surface modification to be able to adsorb oligonucleotides or PCR products. The adsorbed DNA molecules are subsequently printed efficiently on a target surface with high sub-micron resolution. Secondly, we showed that successive stamping is characterized by an exponential decay of the amount of transferred DNA molecules to the surface up the 4th print, then followed by a second regime of transfer that was dependent on the contact time and which resulted in reduced quality of the features. Thus, while consecutive stamping was possible, this procedure turned out to be less reproducible and more time consuming than simply re-inking the stamps between each print. Thirdly, we showed that the hybridization signals on arrays made by microcontact printing were 5 to 10-times higher than those made by conventional spotting methods. Finally, we demonstrated the validity of this microcontact printing method in manufacturing oligonucleotides arrays for mutations recognition in a yeast gene. Conclusion The microcontact printing can be considered as a new potential technology platform to pattern DNA microarrays that may have significant advantages over the conventional spotting technologies as it is easy to implement, it uses low cost material to make the stamp, and the arrays made by this technology are 10-times more sensitive in term of hybridization signals than those manufactured by conventional spotting

  11. Design and development of thermolytic DNA oligonucleotide prodrugs. (United States)

    Grajkowski, Andrzej; Pedras-Vasconcelos, Joao; Ausín, Cristina; Verthelyi, Daniela; Beaucage, Serge L


    Deoxyribonucleoside phosphoramidites functionalized with the thermolytic 2-(N-formyl-N-methyl)aminoethyl group for phosphorus protection (1a-d) have been prepared and employed in the solid-phase synthesis of CpG ODN fma1555. Given that this modified oligonucleotide can be converted to the immunomodulatory CpG ODN 1555 under neutral conditions at 37 degrees C, its biologic activity was demonstrated in vivo by studies showing that intraperitoneal administration of CpG ODN fma1555 in mice resulted in the activation of cytokine-secreting splenocytes. Furthermore, administration of CpG ODN fma1555 to mice that were challenged intradermally in the ear with live L. major metacyclic promastigotes, reduced the severity of Leishmania skin lesions over time to an extent similar to that obtained with CpG ODN 1555. In another infectious model experiment, CpG ODN fma1555 protected newborn mice from death (65% survival) when administered 3 days before infection with the aggressive Tacaribe (TCRV) virus. A comparable immunoprotection was obtained by treatment of TCRV-infected mice with CpG ODN 1555 administered on the same day of infection (45% survival). However, when TCRV-infected mice were treated with CpG ODN fma1555 on the day of infection, they died as a consequence of the relatively slow conversion of the oligonucleotide prodrug to the bioactive CpG ODN 1555. Co-administration of both CpG ODN 1555 and CpG ODN fma1555 to mice 3 days prior to TCRV infection or on the day of infection provided protection from death (45-65% survival) and thus widened the immunoprotection window against TCRV-infection.

  12. Combining gene expression data from different generations of oligonucleotide arrays

    Directory of Open Access Journals (Sweden)

    Kong Sek


    Full Text Available Abstract Background One of the important challenges in microarray analysis is to take full advantage of previously accumulated data, both from one's own laboratory and from public repositories. Through a comparative analysis on a variety of datasets, a more comprehensive view of the underlying mechanism or structure can be obtained. However, as we discover in this work, continual changes in genomic sequence annotations and probe design criteria make it difficult to compare gene expression data even from different generations of the same microarray platform. Results We first describe the extent of discordance between the results derived from two generations of Affymetrix oligonucleotide arrays, as revealed in cluster analysis and in identification of differentially expressed genes. We then propose a method for increasing comparability. The dataset we use consists of a set of 14 human muscle biopsy samples from patients with inflammatory myopathies that were hybridized on both HG-U95Av2 and HG-U133A human arrays. We find that the use of the probe set matching table for comparative analysis provided by Affymetrix produces better results than matching by UniGene or LocusLink identifiers but still remains inadequate. Rescaling of expression values for each gene across samples and data filtering by expression values enhance comparability but only for few specific analyses. As a generic method for improving comparability, we select a subset of probes with overlapping sequence segments in the two array types and recalculate expression values based only on the selected probes. We show that this filtering of probes significantly improves the comparability while retaining a sufficient number of probe sets for further analysis. Conclusions Compatibility between high-density oligonucleotide arrays is significantly affected by probe-level sequence information. With a careful filtering of the probes based on their sequence overlaps, data from different

  13. Design and verification of a pangenome microarray oligonucleotide probe set for Dehalococcoides spp. (United States)

    Hug, Laura A; Salehi, Maryam; Nuin, Paulo; Tillier, Elisabeth R; Edwards, Elizabeth A


    Dehalococcoides spp. are an industrially relevant group of Chloroflexi bacteria capable of reductively dechlorinating contaminants in groundwater environments. Existing Dehalococcoides genomes revealed a high level of sequence identity within this group, including 98 to 100% 16S rRNA sequence identity between strains with diverse substrate specificities. Common molecular techniques for identification of microbial populations are often not applicable for distinguishing Dehalococcoides strains. Here we describe an oligonucleotide microarray probe set designed based on clustered Dehalococcoides genes from five different sources (strain DET195, CBDB1, BAV1, and VS genomes and the KB-1 metagenome). This "pangenome" probe set provides coverage of core Dehalococcoides genes as well as strain-specific genes while optimizing the potential for hybridization to closely related, previously unknown Dehalococcoides strains. The pangenome probe set was compared to probe sets designed independently for each of the five Dehalococcoides strains. The pangenome probe set demonstrated better predictability and higher detection of Dehalococcoides genes than strain-specific probe sets on nontarget strains with pangenome probe set performs more robustly than the combined strain-specific probe sets in the detection of genes not included in the original design. The pangenome probe set represents a highly specific, universal tool for the detection and characterization of Dehalococcoides from contaminated sites. It has the potential to become a common platform for Dehalococcoides-focused research, allowing meaningful comparisons between microarray experiments regardless of the strain examined.

  14. Student Commons (United States)

    Gordon, Douglas


    Student commons are no longer simply congregation spaces for students with time on their hands. They are integral to providing a welcoming environment and effective learning space for students. Many student commons have been transformed into spaces for socialization, an environment for alternative teaching methods, a forum for large group meetings…

  15. Release of DNA oligonucleotides and their conjugates from controlled-pore glass under thermolytic conditions. (United States)

    Grajkowski, Andrzej; Cieślak, Jacek; Norris, Scott; Freedberg, Darón I; Kauffman, Jon S; Duff, Robert J; Beaucage, Serge L


    The sequential functionalization of long-chain alkylamine controlled-pore glass (CPG) with a 3-hydroxypropyl-(2-cyanoethyl)thiophosphoryl linker and a dinucleoside phosphorotetrazolide leads to a uniquely engineered support for solid-phase synthesis. Unlike conventional succinylated-CPG supports, this support is designed to allow oligonucleotide deprotection and elimination of deprotection side-products to proceed without release of the oligonucleotide. When needed, the DNA oligonucleotide can be thermolytically released in 2 hr under essentially neutral conditions. The modified CPG support has been successfully employed in the synthesis of both native and fully phosphorothioated DNA 20-mers. On the basis of reversed-phase HPLC and electrophoretic analyses, the purity of the released oligonucleotides is comparable to that of identical oligonucleotides synthesized from succinylated-CPG supports, in terms of both shorter-than-full-length oligonucleotide contaminants and overall yields. The detailed preparation of DNA oligonucleotides conjugated with exemplary reporter or functional groups, either at the 3'-terminus or at both 3'- and 5'-termini, is also described.

  16. Polymerase-endonuclease amplification reaction (PEAR for large-scale enzymatic production of antisense oligonucleotides.

    Directory of Open Access Journals (Sweden)

    Xiaolong Wang

    Full Text Available Antisense oligonucleotides targeting microRNAs or their mRNA targets prove to be powerful tools for molecular biology research and may eventually emerge as new therapeutic agents. Synthetic oligonucleotides are often contaminated with highly homologous failure sequences. Synthesis of a certain oligonucleotide is difficult to scale up because it requires expensive equipment, hazardous chemicals and a tedious purification process. Here we report a novel thermocyclic reaction, polymerase-endonuclease amplification reaction (PEAR, for the amplification of oligonucleotides. A target oligonucleotide and a tandem repeated antisense probe are subjected to repeated cycles of denaturing, annealing, elongation and cleaving, in which thermostable DNA polymerase elongation and strand slipping generate duplex tandem repeats, and thermostable endonuclease (PspGI cleavage releases monomeric duplex oligonucleotides. Each round of PEAR achieves over 100-fold amplification. The product can be used in one more round of PEAR directly, and the process can be further repeated. In addition to avoiding dangerous materials and improved product purity, this reaction is easy to scale up and amenable to full automation. PEAR has the potential to be a useful tool for large-scale production of antisense oligonucleotide drugs.

  17. Chimeric RNA Oligonucleotides with Triazole and Phosphate Linkages: Synthesis and RNA Interference. (United States)

    Fujino, Tomoko; Kogashi, Kanako; Okada, Koudai; Mattarella, Martin; Suzuki, Takeru; Yasumoto, Kenichi; Sogawa, Kazuhiro; Isobe, Hiroyuki


    Chimeric RNA oligonucleotides with an artificial triazole linker were synthesized using solution-phase click chemistry and solid-phase automated synthesis. Scalable synthesis methods for jointing units for the chimeric structure have been developed, and after click-coupling of the jointing units with triazole linkers, a series of chimeric oligonucleotides was prepared by utilizing the well-established phosphoramidite method for the elongation. The series of chimeric 21-mer oligonucleotides that possessed the triazole linker at different strands and positions allowed for a screening study of the RNA interference to clarify the preference of the triazole modifications in small-interfering RNA molecules.

  18. Common Courses for Common Purposes:

    DEFF Research Database (Denmark)

    Schaub Jr, Gary John


    (PME)? I suggest three alternative paths that increased cooperation in PME at the level of the command and staff course could take: a Nordic Defence College, standardized national command and staff courses, and a core curriculum of common courses for common purposes. I conclude with a discussion of how...

  19. Chemoselective Coupling Preserves the Substrate Integrity of Surface-Immobilized Oligonucleotides for Emulsion PCR-Based Gene Library Construction. (United States)

    Malone, Marie L; Cavett, Valerie J; Paegel, Brian M


    Combinatorial bead libraries figure prominently in next-generation sequencing and are also important tools for in vitro evolution. The most common methodology for generating such bead libraries, emulsion PCR (emPCR), enzymatically extends bead-immobilized oligonucleotide PCR primers in emulsion droplets containing a single progenitor library member. Primers are almost always immobilized on beads via noncovalent biotin-streptavidin binding. Here, we describe covalent bead functionalization with primers (∼10(6) primers/2.8-μm-diameter bead) via either azide-alkyne click chemistry or Michael addition. The primers are viable polymerase substrates (4-7% bead-immobilized enzymatic extension product yield from one thermal cycle). Carbodiimide-activated carboxylic acid beads only react with oligonucleotides under conditions that promote nonspecific interactions (low salt, low pH, no detergent), comparably immobilizing primers on beads, but yielding no detectable enzymatic extension product. Click-functionalized beads perform satisfactorily in emPCR of a site-saturation mutagenesis library, generating monoclonal templated beads (10(4)-10(5) copies/bead, 1.4-kb amplicons). This simpler, chemical approach to primer immobilization may spur more economical library preparation for high-throughput sequencing and enable more complex surface elaboration for in vitro evolution.

  20. QCI Common

    Energy Technology Data Exchange (ETDEWEB)


    There are many common software patterns and utilities for the ORNL Quantum Computing Institute that can and should be shared across projects. Otherwise we find duplication of code which adds unwanted complexity. This is a software product seeks to alleviate this by providing common utilities such as object factories, graph data structures, parameter input mechanisms, etc., for other software products within the ORNL Quantum Computing Institute. This work enables pure basic research, has no export controlled utilities, and has no real commercial value.

  1. Design and evaluation of 16S rRNA sequence based oligonucleotide probes for the detection and quantification of Comamonas testosteroni in mixed microbial communities

    Directory of Open Access Journals (Sweden)

    Bathe Stephan


    Full Text Available Abstract Background The β-proteobacterial species Comamonas testosteroni is capable of biotransformation and also biodegradation of a range of chemical compounds and thus potentially useful in chemical manufacturing and bioremediation. The ability to detect and quantify members of this species in mixed microbial communities thus may be desirable. Results We have designed an oligonucleotide probe for use in fluorescent in situ hybridization (FISH and two pairs of PCR primers targeting a C. testosteroni subgroup. The FISH probe and one of the PCR primer pairs are suitable for quantification of C. testosteroni in mixed microbial communities using FISH followed by quantitative image analysis or real-time quantitative PCR, respectively. This has been shown by analysis of samples from an enrichment of activated sludge on testosterone resulting in an increase in abundance and finally isolation of C. testosteroni. Additionally, we have successfully used quantitative PCR to follow the C. testosteroni abundance during a laboratory scale wastewater bioaugmentation experiment. Conclusion The oligonucleotides presented here provide a useful tool to study C. testosteroni population dynamics in mixed microbial communities.

  2. Instituting Commoning

    Directory of Open Access Journals (Sweden)

    . STEALTH.unlimited


    Full Text Available Starting from the origins of the notion of management, this paper explores how commons governance is constituted by the earlier influential research of Elinor Ostrom, and pursues this with reference to scholars such as Saki Bailey, who emphasises that the choice of regulatory frame is ultimately a political one. We then argue that commons have to be ‘instituted’ in an open manner in order to remain accessible. This demands a set of scripts, rules or agreements that keep the process of commoning in place, and, simultaneously, keep commoning in a constant process of reproduction. We examine this tension and look at the shift in understanding about what ‘institutions of the commons’ have entailed in practice over the course of the last century and a half. Finally, we return to the political dimension to touch upon the question of whether, with the disappearance of the welfare state, a coherent concept of society can emerge from the current upsurge of commons initiatives.

  3. Oligonucleotide-based biosensors for in vitro diagnostics and environmental hazard detection. (United States)

    Jung, Il Young; Lee, Eun Hee; Suh, Ah Young; Lee, Seung Jin; Lee, Hyukjin


    Oligonucleotide-based biosensors have drawn much attention because of their broad applications in in vitro diagnostics and environmental hazard detection. They are particularly of interest to many researchers because of their high specificity as well as excellent sensitivity. Recently, oligonucleotide-based biosensors have been used to achieve not only genetic detection of targets but also the detection of small molecules, peptides, and proteins. This has further broadened the applications of these sensors in the medical and health care industry. In this review, we highlight various examples of oligonucleotide-based biosensors for the detection of diseases, drugs, and environmentally hazardous chemicals. Each example is provided with detailed schematics of the detection mechanism in addition to the supporting experimental results. Furthermore, future perspectives and new challenges in oligonucleotide-based biosensors are discussed.

  4. Exploiting Protected Maleimides to Modify Oligonucleotides, Peptides and Peptide Nucleic Acids

    Directory of Open Access Journals (Sweden)

    Clément Paris


    Full Text Available This manuscript reviews the possibilities offered by 2,5-dimethylfuran-protected maleimides. Suitably derivatized building blocks incorporating the exo Diels-Alder cycloadduct can be introduced at any position of oligonucleotides, peptide nucleic acids, peptides and peptoids, making use of standard solid-phase procedures. Maleimide deprotection takes place upon heating, which can be followed by either Michael-type or Diels-Alder click conjugation reactions. However, the one-pot procedure in which maleimide deprotection and conjugation are simultaneously carried out provides the target conjugate more quickly and, more importantly, in better yield. This procedure is compatible with conjugates involving oligonucleotides, peptides and peptide nucleic acids. A variety of cyclic peptides and oligonucleotides can be obtained from peptide and oligonucleotide precursors incorporating protected maleimides and thiols.

  5. Nucleoside, nucleotide and oligonucleotide based amphiphiles: a successful marriage of nucleic acids with lipids. (United States)

    Gissot, Arnaud; Camplo, Michel; Grinstaff, Mark W; Barthélémy, Philippe


    Amphiphilic molecules based on nucleosides, nucleotides and oligonucleotides are finding more and more biotechnological applications. This Perspective highlights their synthesis, supramolecular organization as well as their applications in the field of biotechnology.

  6. Science commons

    CERN Document Server

    CERN. Geneva


    SCP: Creative Commons licensing for open access publishing, Open Access Law journal-author agreements for converting journals to open access, and the Scholar's Copyright Addendum Engine for retaining rights to self-archive in meaningful formats and locations for future re-use. More than 250 science and technology journals already publish under Creative Commons licensing while 35 law journals utilize the Open Access Law agreements. The Addendum Engine is a new tool created in partnership with SPARC and U.S. universities. View John Wilbanks's biography

  7. Creative Commons

    DEFF Research Database (Denmark)

    Jensen, Lone


    En Creative Commons licens giver en forfatter mulighed for at udbyde sit værk i en alternativ licensløsning, som befinder sig på forskellige trin på en skala mellem yderpunkterne "All rights reserved" og "No rights reserved". Derved opnås licensen "Some rights reserved"......En Creative Commons licens giver en forfatter mulighed for at udbyde sit værk i en alternativ licensløsning, som befinder sig på forskellige trin på en skala mellem yderpunkterne "All rights reserved" og "No rights reserved". Derved opnås licensen "Some rights reserved"...

  8. Advantages of ion-exchange chromatography for oligonucleotide analysis. (United States)

    Cook, Ken; Thayer, Jim


    The rapid development of therapeutic oligonucleotides (ONs) has created a need for in-depth characterization of ONs, beyond previous requirements. The natural migration to LC-MS requires the use of chromatography with MS-compatible eluents to introduce the large, highly charged biopolymers into the mass spectrometer. Most frequently this employs ion-pair reversed-phase liquid chromatography, which may leave gaps in the characterization, but these can be filled with the use of high-resolution ion-exchange chromatography. Several classes of isobaric isomers are among the impurities that will require further separation prior to MS analysis. This review shows how the use of ion exchange as an additional orthogonal analytical method can be used as standalone or interfaced with MS to achieve the highest possible analytical coverage in the characterization and quantification of impurities present in single- and double-stranded ON formulations. Some of these techniques have been in use for some time and the importance of others is just being recognized.

  9. Antineoplastic effect of decoy oligonucleotide derived from MGMT enhancer.

    Directory of Open Access Journals (Sweden)

    Tamar Canello

    Full Text Available Silencing of O(6-methylguanine-DNA-methyltransferase (MGMT in tumors, mainly through promoter methylation, correlates with a better therapeutic response and with increased survival. Therefore, it is conceivable to consider MGMT as a potential therapeutic target for the treatment of cancers. Our previous results demonstrated the pivotal role of NF-kappaB in MGMT expression, mediated mainly through p65/NF-kappaB homodimers. Here we show that the non-canonical NF-KappaB motif (MGMT-kappaB1 within MGMT enhancer is probably the major inducer of MGMT expression following NF-kappaB activation. Thus, in an attempt to attenuate the transcription activity of MGMT in tumors we designed locked nucleic acids (LNA modified decoy oligonucleotides corresponding to the specific sequence of MGMT-kappaB1 (MGMT-kB1-LODN. Following confirmation of the ability of MGMT-kB1-LODN to interfere with the binding of p65/NF-kappaB to the NF-KappaB motif within MGMT enhancer, the efficacy of the decoy was studied in-vitro and in-vivo. The results of these experiments show that the decoy MGMT-kB1-LODN have a substantial antineoplastic effect when used either in combination with temozolomide or as monotherapy. Our results suggest that MGMT-kB1-LODN may provide a novel strategy for cancer therapy.

  10. Integrated Microfluidic Isolation of Aptamers Using Electrophoretic Oligonucleotide Manipulation (United States)

    Kim, Jinho; Olsen, Timothy R.; Zhu, Jing; Hilton, John P.; Yang, Kyung-Ae; Pei, Renjun; Stojanovic, Milan N.; Lin, Qiao


    We present a microfluidic approach to integrated isolation of DNA aptamers via systematic evolution of ligands by exponential enrichment (SELEX). The approach employs a microbead-based protocol for the processes of affinity selection and amplification of target-binding oligonucleotides, and an electrophoretic DNA manipulation scheme for the coupling of these processes, which are required to occur in different buffers. This achieves the full microfluidic integration of SELEX, thereby enabling highly efficient isolation of aptamers in drastically reduced times and with minimized consumption of biological material. The approach as such also offers broad target applicability by allowing selection of aptamers with respect to targets that are either surface-immobilized or solution-borne, potentially allowing aptamers to be developed as readily available affinity reagents for a wide range of targets. We demonstrate the utility of this approach on two different procedures, respectively for isolating aptamers against a surface-immobilized protein (immunoglobulin E) and a solution-phase small molecule (bisboronic acid in the presence of glucose). In both cases aptamer candidates were isolated in three rounds of SELEX within a total process time of approximately 10 hours.

  11. The development of bioactive triple helix-forming oligonucleotides. (United States)

    Seidman, Michael M; Puri, Nitin; Majumdar, Alokes; Cuenoud, Bernard; Miller, Paul S; Alam, Rowshon


    We are developing triple helix-forming oligonucleotides (TFOs) as gene targeting reagents in mammalian cells. We have described psoralen-conjugated TFOs containing 2'-O-methyl (2'OMe) and 2'-O-aminoethoxy (AE) ribose substitutions. TFOs with a cluster of 3-4 AE residues, with all other sugars as 2'OMe, were bioactive in a gene knockout assay in mammalian cells. In contrast, TFOs with one or two clustered, or three dispersed, AE residues were inactive. Thermal stability analysis of the triplexes indicated that there were only incremental differences between the active and inactive TFOs. However the active and inactive TFOs could be distinguished by their association kinetics. The bioactive TFOs showed markedly greater on-rates than the inactive TFOs. It appears that the on-rate is a better predictor of TFO bioactivity than thermal stability. Our data are consistent with a model in which a cluster of 3-4 AE residues stabilizes the nucleation event that precedes formation of a complete triplex. It is likely that triplexes in cells are much less stable than triplexes in vitro probably as a result of elution by chromatin-associated translocases and helicases. Consequently the biologic assay will favor TFOs that can bind and rebind genomic targets quickly.

  12. Advancements of antisense oligonucleotides in treatment of breast cancer

    Institute of Scientific and Technical Information of China (English)

    YANGShuan-Ping; SONGSan-Tai; 等


    Breast cancer is one kind of multi-gene related malignancy.Overexpression of some oncogenes such as HER-2(c-erbB-2,Neu),bcl-2/bcl-xL,protein kinase A(PKA),and transferrin receptor gene(TfR gene),etc significantly affect the prognosis of breast cancer.It was shown that specific suppression of the overexpressed genes above resulted in the improvement of the therapy of breast cancer.Antisense of useful tools for inhibiting the overexpression of specific oncogenes,was involved in the therapy of breast cancer in recent years. Data indicated that antisense oligonucleotides(ON)could inhibit specially the expression of the target genes on mRNA or protein levels in most of cases;some ON candidates showed encouraging therapeutic effects in vitro and in vivo on breast cancer cell lines or xenografts.Furthermore,the combination use of the antisense ON and normal chemotherapeutic agents indicated synergistic antitumor effects,which was probably the best utilization of antisense ON in the treatment of breast cancer.

  13. Antineoplastic effect of decoy oligonucleotide derived from MGMT enhancer. (United States)

    Canello, Tamar; Ovadia, Haim; Refael, Miri; Zrihan, Daniel; Siegal, Tali; Lavon, Iris


    Silencing of O(6)-methylguanine-DNA-methyltransferase (MGMT) in tumors, mainly through promoter methylation, correlates with a better therapeutic response and with increased survival. Therefore, it is conceivable to consider MGMT as a potential therapeutic target for the treatment of cancers. Our previous results demonstrated the pivotal role of NF-kappaB in MGMT expression, mediated mainly through p65/NF-kappaB homodimers. Here we show that the non-canonical NF-KappaB motif (MGMT-kappaB1) within MGMT enhancer is probably the major inducer of MGMT expression following NF-kappaB activation. Thus, in an attempt to attenuate the transcription activity of MGMT in tumors we designed locked nucleic acids (LNA) modified decoy oligonucleotides corresponding to the specific sequence of MGMT-kappaB1 (MGMT-kB1-LODN). Following confirmation of the ability of MGMT-kB1-LODN to interfere with the binding of p65/NF-kappaB to the NF-KappaB motif within MGMT enhancer, the efficacy of the decoy was studied in-vitro and in-vivo. The results of these experiments show that the decoy MGMT-kB1-LODN have a substantial antineoplastic effect when used either in combination with temozolomide or as monotherapy. Our results suggest that MGMT-kB1-LODN may provide a novel strategy for cancer therapy.

  14. Nanoexplosive gene therapy using triplex-forming oligonucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Eun Jung; Min, Hye Jung; Choe, Jae Gol; Park, Gil Hong; Kim, Meyoung Kon [College of Medicine, Korea Univ., Seoul (Korea, Republic of)


    Triplex forming oligonucleotides (TFO) labeled with Auger emitter could be ideal vehicles for delivering radiation energy to specific DNA sequences, and followed by double-stranded DNA breaks and subsequent inactivation of targeted genes. We designed TFOs targeting the selected DNA fragments (i.e., estrogen receptors and N-myc promoter) and labeled with {sup 125}I and {sup 111}In. Various Cancer cells, e.g., MCF-7 (breast adenocarcinoma), MCF-10A (immortalized breast cells), Jurkat (T-cell leukemia), ARO (thyroid cancer), SNU-449 (Colon Caner), and HL-60 (polymyelocytic leukemia), were prepared and treated with radiolabeled TFO for 24 h. After the incubation, subcellular fractions (i.e., cell nucleus, cytoplasm and cultured medium) were collected and measured radioactivity by a gamma scintillation counter, respectively. The mean value of % injected dose for each fraction was ranged as follows: nucleus, 4.4-20%; cytoplasm, 8.2-29%; and medium, 64-87%. Therefore, we speculated that TFO labeled with Auger emitter could be a next-generation therapeutic tool in nanoexplosive gene therapy.

  15. Respirable antisense oligonucleotides: a new drug class for respiratory disease

    Directory of Open Access Journals (Sweden)

    Tanaka Makoto


    Full Text Available Abstract Respirable antisense oligonucleotides (RASONs, which attenuate specific disease-associated mRNAs, represent a new class of respiratory therapeutics with considerable potential. RASONs overcome previous obstacles that have impeded the development of antisense therapeutics targeting diseases in other organ systems. RASONs are delivered directly to the target tissue via inhalation; their uptake seems to be enhanced by cationic properties inherent in pulmonary surfactant, and, because of the markedly different target properties of mRNA and proteins, they can have very long durations of effect compared with traditional drugs targeting the protein of the same gene. RASONs contain chemical modifications that decrease their degradation by cellular nucleases. However, total insensitivity to nucleases is probably not an optimal design criterion for RASONs, because moderate nuclease sensitivity can prevent their systemic delivery, decreasing the potential for systemic toxicity. EPI-2010 is a 21-mer phosphorothioate RASON that attenuates bronchoconstriction, inflammation and surfactant depletion in preclinical models of human asthma, has a duration of effect of seven days, and seems to undergo minimal systemic delivery.

  16. Sheath liquid effects in capillary high-performance liquid chromatography-electrospray mass spectrometry of oligonucleotides. (United States)

    Huber, C G; Krajete, A


    Fused-silica capillary columns of 200 microm inner diameter were packed with micropellicular, octadecylated, 2.3 microm poly(styrene-divinylbenzene) particles and applied to the separation of oligonucleotides by ion-pair reversed-phase high-performance liquid chromatography. Oligonucleotides were eluted at 50 degrees C with gradients of 3-13% acetonitrile in 50 mM triethylammonium bicarbonate. Addition of sheath liquid to the column effluent allowed the detection of oligonucleotides by electrospray ionization mass spectrometry using full-scan data acquisition with a detectability comparable to that obtained with UV detection. The signal-to-noise ratios with different sheath liquids increased in the order isopropanololigonucleotides longer than 20 nucleotide units whereas no significant effect was observed with shorter oligonucleotides. Organic acids and bases in the sheath liquid generally deteriorated the signal-to-noise ratios in the chromatograms and mass spectra mainly because of increased background noise. Only a few charge states were observed in the mass spectra of oligonucleotides because of charge state reduction due to the presence of carbonic acid in the eluent. With triethylammonium hydrogencarbonate as chromatographic eluent and acetonitrile as sheath liquid, very few cation adducts of oligonucleotides were observed in the mass spectra. However, the presence of small amounts of monopotassium adducts enabled the calculation of the charge state of multiply charged ions. With acetonitrile as sheath liquid, 710 amol of a 16-mer oligonucleotide were detected using selected ion monitoring data acquisition with a signal-to-noise ratio of 3:1. Finally, capillary ion-pair reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry was

  17. Complexes of carbon nanotubes with oligonucleotides in thin Langmuir-Blodgett films to detect electrochemically hybridization (United States)

    Egorov, A. S.; Egorova, V. P.; Krylova, H. V.; Lipnevich, I. V.; Orekhovskaya, T. I.; Veligura, A. A.; Govorov, M. I.; Shulitsky, B. G.


    Self-assembled complexes consisting of thin multi-walled carbon nanotubes (MWCNTs) and DNA-oligonucleotides which are able to a cooperative binding to complementary oligonucleotides have been investigated. It was establised a high-performance charge transport in nanostructured Langmuir-Blodgett complexes thin MWCNTs/DNA. A method to electrochemically detect DNA hybridization on the self-organized structures has been proposed.

  18. Conceptual "Heat-Driven" approach to the synthesis of DNA oligonucleotides on microarrays. (United States)

    Grajkowski, A; Cieślak, J; Chmielewski, M K; Marchán, V; Phillips, L R; Wilk, A; Beaucage, S L


    The discovery of deoxyribonucleoside cyclic N-acylphosphoramidites, a novel class of phosphoramidite monomers for solid-phase oligonucleotide synthesis, has led to the development of a number of phosphate protecting groups that can be cleaved from DNA oligonucleotides under thermolytic neutral conditions. These include the 2-(N-formyl-N-methyl)aminoethyl, 4-oxopentyl, 3-(N-tert-butyl)carboxamido-1-propyl, 3-(2-pyridyl)-1-propyl, 2-[N-methyl-N-(2-pyridyl)]aminoethyl, and 4-methythiobutyl groups. When used for 5'-hydroxyl protection of nucleosides, the analogous 1-phenyl-2-[N-methyl-N-(2-pyridyl)]aminoethyloxycarbonyl group exhibited excellent thermolytic properties, which may permit an iterative "heat-driven" synthesis of DNA oligonucleotides on microarrays. In this regard, progress has been made toward the use of deoxyribonucleoside cyclic N-acylphosphoramidites in solid-phase oligonucleotide syntheses without nucleobase protection. Given that deoxyribonucleoside cyclic N-acylphosphoramidites produce oligonucleotides with heat-sensitive phosphate protecting groups, blocking the 5'-hydroxyl of these monomers with, for example, the thermolabile 1-phenyl-2-[N-methyl-N-(2-pyridyl)]aminoethyloxycarbonyl group may provide a convenient thermo-controlled method for the synthesis of oligonucleotides on microarrays.

  19. Strategies in the preparation of DNA oligonucleotide arrays for diagnostic applications. (United States)

    Beaucage, S L


    This report emphasizes the interfacial chemistry that is required to ensure proper attachment of oligonucleotides onto the surface of microarrays. For example, strategies for the covalent attachment of pre-synthesized oligonucleotides to glass slides, gold films, polyacrylamide gel pads, polypyrrole films, and optical fibers are surveyed in an attempt to better define the parameters for optimal formation and detection of DNA hybrids. These parameters include among others, the nature and length of the linkers attaching oligonucleotides to the arrays, and the surface density of oligonucleotides required for unhindered hybridization with DNA targets. Sensitive detection methods such as the use of light-scattering techniques, molecular beacons, surface plasmon resonance, attenuated total internal reflection-FTIR, and the evanescent field excitation of fluorescence from surface-bound fluorophores have been developed to study the kinetics and specificity of hybridization events. Finally, the synthesis of oligonucleotides directly on glass surfaces and polypropylene sheets has been investigated to enable DNA sequencing by hybridization and achieve oligonucleotide densities of ca. 10(6) sequences per cm(2) on DNA chips.

  20. Oligonucleotide chip, real-time PCR and sequencing for genotyping of hepatitis B virus

    Institute of Scientific and Technical Information of China (English)

    Yong-Zhong Wang; Guo-Xiang Wu; Li-Bo Luo; Min Chen; Li-Hua Ruan


    AIM: To compare the oligonucleotide chip, real-time PCR and sequencing for genotyping of hepatitis B virus in Chinese patients with chronic hepatitis B.METHODS: Mixture of samples with different genotypes and clinical serum samples from 126 chronic hepatitis B patients was tested for hepatitis B virus genotypes by oligonucleotide chip, real-time PCR and sequencing of PCR products, respectively. Clinical performances, time required and costs of the three assays were evaluated.RESULTS: Oligonucleotide chips and real-time PCR detected 1% and 0.1% genotypes, respectively, in mixed samples. Of the 126 clinical samples from patients with chronic hepatitis B, genotype B was detected in 41(33%), 41 (33%) and 45 (36%) samples, and genotype C in 76 (60%), 76 (60%) and 81 (64%) samples, by oligonucleotide chip, real-time PCR and sequencing,respectively. Oligonucleotide chip and real-time PCR detected mixed genotypes B and C in 9 samples. Realtime PCR was the rapidest and cheapest among the three assays.CONCLUSION: Oligonucleotide chip and real-time PCR are able to detect mixed genotypes, while sequencing only detects the dominant genotype in clinical samples.

  1. Improving signal intensities for genes with low-expression on oligonucleotide microarrays

    Directory of Open Access Journals (Sweden)

    Hu Limei


    Full Text Available Abstract Background DNA microarrays using long oligonucleotide probes are widely used to evaluate gene expression in biological samples. These oligonucleotides are pre-synthesized and sequence-optimized to represent specific genes with minimal cross-hybridization to homologous genes. Probe length and concentration are critical factors for signal sensitivity, particularly when genes with various expression levels are being tested. We evaluated the effects of oligonucleotide probe length and concentration on signal intensity measurements of the expression levels of genes in a target sample. Results Selected genes of various expression levels in a single cell line were hybridized to oligonucleotide arrays of four lengths and four concentrations of probes to determine how these critical parameters affected the intensity of the signal representing their expression. We found that oligonucleotides of longer length significantly increased the signals of genes with low-expression in the target. High-expressing gene signals were also boosted but to a lesser degree. Increasing the probe concentration, however, did not linearly increase the signal intensity for either low- or high-expressing genes. Conclusions We conclude that the longer the oligonuclotide probe the better the signal intensities of low expressing genes on oligonucleotide arrays.

  2. Porous silicon-cell penetrating peptide hybrid nanocarrier for intracellular delivery of oligonucleotides. (United States)

    Rytkönen, Jussi; Arukuusk, Piret; Xu, Wujun; Kurrikoff, Kaido; Langel, Ulo; Lehto, Vesa-Pekka; Närvänen, Ale


    The largest obstacle to the use of oligonucleotides as therapeutic agents is the delivery of these large and negatively charged biomolecules through cell membranes into intracellular space. Mesoporous silicon (PSi) is widely recognized as a potential material for drug delivery purposes due to its several beneficial features like large surface area and pore volume, high loading capacity, biocompatibility, and biodegradability. In the present study, PSi nanoparticles stabilized by thermal oxidation or thermal carbonization and subsequently modified by grafting aminosilanes on the surface are utilized as an oligonucleotide carrier. Splice correcting oligonucleotides (SCOs), a model oligonucleotide drug, were loaded into the positively charged PSi nanoparticles with a loading degree as high as 14.3% (w/w). Rapid loading was achieved by electrostatic interactions, with the loading efficiencies reaching 100% within 5 min. The nanoparticles were shown to deliver and release SCOs, in its biologically active form, inside cells when formulated together with cell penetrating peptides (CPP). The biological effect was monitored with splice correction assay and confocal microscopy utilizing HeLa pLuc 705 cells. Furthermore, the use of PSi carrier platform in oligonucleotide delivery did not reduce the cell viability. Additionally, the SCO-CPP complexes formed in the pores of the carrier were stabilized against proteolytic digestion. The advantageous properties of protecting and releasing the cargo and the possibility to further functionalize the carrier surface make the hybrid nanoparticles a potential system for oligonucleotide delivery.

  3. The solar photospheric abundance of zirconium

    CERN Document Server

    Caffau, Elisabetta; Ludwig, Hans-Günter; Bonifacio, Piercarlo; Steffen, Matthias


    Zirconium (Zr), together with strontium and yttrium, is an important element in the understanding of the Galactic nucleosynthesis. In fact, the triad Sr-Y-Zr constitutes the first peak of s-process elements. Despite its general relevance not many studies of the solar abundance of Zr were conducted. We derive the zirconium abundance in the solar photosphere with the same CO5BOLD hydrodynamical model of the solar atmosphere that we previously used to investigate the abundances of C-N-O. We review the zirconium lines available in the observed solar spectra and select a sample of lines to determine the zirconium abundance, considering lines of neutral and singly ionised zirconium. We apply different line profile fitting strategies for a reliable analysis of Zr lines that are blended by lines of other elements. The abundance obtained from lines of neutral zirconium is very uncertain because these lines are commonly blended and weak in the solar spectrum. However, we believe that some lines of ionised zirconium are...

  4. DNA sequence analysis by hybridization with oligonucleotide microchips : MALDI mass spectrometry identification of 5mers contiguously stacked to microchip oligonucleotides.

    Energy Technology Data Exchange (ETDEWEB)

    Stomakhin, A. A.; Vasiliskov, V. A.; Timofeev, E.; Schulga, D.; Cotter, R. J.; Mirzabekov, A. D.; Biochip Technology Center; Engelhardt Inst. of Molecular Biology; Moscow Inst. of Physics and Technology; Middle Atlantic Mass Spectrometry Lab.; Johns Hopkins Univ. School of Medicine


    Matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) has been applied to increase the informational output from DNA sequence analysis. It has been used to analyze DNA by hybridization with microarrays of gel-immobilized oligonucleotides extended with stacked 5mers. In model experiments, a 28 nt long DNA fragment was hybridized with 10 immobilized, overlapping 8mers. Then, in a second round of hybridization DNA-8mer duplexes were hybridized with a mixture of 10 5mers. The stability of the 5mer complex with DNA was increased to raise the melting temperature of the duplex by 10-15{sup o}C as a result of stacking interaction with 8mers. Contiguous 13 bp duplexes containing an internal break were formed. MALDI MS identified one or, in some cases, two 5mers contiguously stacked to each DNA-8mer duplex formed on the microchip. Incorporating a mass label into 5mers optimized MALDI MS monitoring. This procedure enabled us to reconstitute the sequence of a model DNA fragment and identify polymorphic nucleotides. The application of MALDI MS identification of contiguously stacked 5mers to increase the length of DNA for sequence analysis is discussed.

  5. Primordial Deuterium Abundance Measurements

    CERN Document Server

    Levshakov, S A; Takahara, F; Levshakov, Sergei A.; Kegel, Wilhelm H.; Takahara, Fumio


    Deuterium abundances measured recently from QSO absorption-line systems lie in the range from 3 10^{-5} to 3 10^{-4}, which shed some questions on standard big bang theory. We show that this discordance may simply be an artifact caused by inadequate analysis ignoring spatial correlations in the velocity field in turbulent media. The generalized procedure (accounting for such correlations) is suggested to reconcile the D/H measurements. An example is presented based on two high-resolution observations of Q1009+2956 (low D/H) [1,2] and Q1718+4807 (high D/H) [8,9]. We show that both observations are compatible with D/H = 4.1 - 4.6 10^{-5}, and thus support SBBN. The estimated mean value = 4.4 10^{-5} corresponds to the baryon-to-photon ratio during SBBN eta = 4.4 10^{-10} which yields the present-day baryon density Omega_b h^2 = 0.015.

  6. Down-regulation of Survivin by Antisense Oligonucleotides Increases Apoptosis, Inhibits Cytokinesis and Anchorage-Independent Growth

    Directory of Open Access Journals (Sweden)

    Jun Chen


    Full Text Available Survivin, a member of the inhibitor of apoptosis protein (IAP family, is detected in most common human cancers but not in adjacent normal cells. Previous studies suggest that survivin associates with the mitotic spindle and directly inhibits caspase activity. To further investigate the function of survivin, we used a survivin antisense (AS oligonucleotide to downregulate survivin expression in normal and cancer cells. We found that inhibition of survivin expression increased apoptosis and polyploidy while decreasing colony formation in soft agar. Immunohistochemistry showed that cells without survivin can initiate the cleavage furrow and contractile ring, but cannot complete cytokinesis, thus resulting in multinucleated cells. These findings indicate that survivin plays important roles in a late stage of cytokinesis, as well as in apoptosis.

  7. Profiled support vector machines for antisense oligonucleotide efficacy prediction

    Directory of Open Access Journals (Sweden)

    Martín-Guerrero José D


    Full Text Available Abstract Background This paper presents the use of Support Vector Machines (SVMs for prediction and analysis of antisense oligonucleotide (AO efficacy. The collected database comprises 315 AO molecules including 68 features each, inducing a problem well-suited to SVMs. The task of feature selection is crucial given the presence of noisy or redundant features, and the well-known problem of the curse of dimensionality. We propose a two-stage strategy to develop an optimal model: (1 feature selection using correlation analysis, mutual information, and SVM-based recursive feature elimination (SVM-RFE, and (2 AO prediction using standard and profiled SVM formulations. A profiled SVM gives different weights to different parts of the training data to focus the training on the most important regions. Results In the first stage, the SVM-RFE technique was most efficient and robust in the presence of low number of samples and high input space dimension. This method yielded an optimal subset of 14 representative features, which were all related to energy and sequence motifs. The second stage evaluated the performance of the predictors (overall correlation coefficient between observed and predicted efficacy, r; mean error, ME; and root-mean-square-error, RMSE using 8-fold and minus-one-RNA cross-validation methods. The profiled SVM produced the best results (r = 0.44, ME = 0.022, and RMSE= 0.278 and predicted high (>75% inhibition of gene expression and low efficacy ( Conclusions The SVM approach is well suited to the AO prediction problem, and yields a prediction accuracy superior to previous methods. The profiled SVM was found to perform better than the standard SVM, suggesting that it could lead to improvements in other prediction problems as well.

  8. A simple and rapid method for the preparation of homologous DNA oligonucleotide hybridization probes from heterologous gene sequences and probes. (United States)

    Maxwell, E S; Sarge, K D


    We describe a simple and rapid method for the preparation of homologous DNA oligonucleotide probes for hybridization analysis and/or cDNA/genomic library screening. With this method, a synthetic DNA oligonucleotide derived from a known heterologous DNA/RNA/protein sequence is annealed to an RNA preparation containing the gene transcript of interest. Any unpaired 3'-terminal oligonucleotides of the heterologous DNA primer are then removed using the 3' exonuclease activity of the DNA Polymerase I Klenow fragment before primer extension/dideoxynucleotide sequencing of the annealed RNA species with AMV reverse transcriptase. From the determined RNA sequence, a completely homologous DNA oligonucleotide probe is then prepared. This approach has been used to prepare a homologous DNA oligonucleotide probe for the successful library screening of the yeast hybRNA gene starting with a heterologous mouse hybRNA DNA oligonucleotide probe.

  9. Diffusion of Oligonucleotides from within Iron-Crosslinked Polyelectrolyte-Modified Alginate Beads: A Model System for Drug Release

    CERN Document Server

    Privman, Vladimir; Luz, Roberto A S; Guz, Nataliia; Glasser, M Lawrence; Katz, Evgeny


    We developed and experimentally verified an analytical model to describe diffusion of oligonucleotides from stable hydrogel beads. The synthesized alginate beads are Fe3+-cross-linked as well as polyelectrolyte-doped for uniformity and stability at physiological pH. Data on diffusion of oligonucleotides from inside the beads provide physical insights into the volume nature of the immobilization of a fraction of oligonucleotides due to polyelectrolyte cross-linking, i.e., the absence of the surface-layer barrier in this case. Furthermore, our results suggest a new simple approach to measuring the diffusion coefficient of the mobile oligonucleotide molecules inside hydrogel. The considered alginate beads provide a model for a well-defined component in drug release systems and for the oligonucleotide-release transduction steps in drug-delivering and biocomputing applications. This is illustrated by destabilizing the beads with citrate that induces full oligonucleotide release with non-diffusional kinetics.

  10. Analyses of point mutation repair and allelic heterogeneity generated by CRISPR/Cas9 and single-stranded DNA oligonucleotides


    Pawel Bialk; Brett Sansbury; Natalia Rivera-Torres; Kevin Bloh; Dula Man; Kmiec, Eric B.


    The repair of a point mutation can be facilitated by combined activity of a single-stranded oligonucleotide and a CRISPR/Cas9 system. While the mechanism of action of combinatorial gene editing remains to be elucidated, the regulatory circuitry of nucleotide exchange executed by oligonucleotides alone has been largely defined. The presence of the appropriate CRISPR/Cas9 system leads to an enhancement in the frequency of gene editing directed by single-stranded DNA oligonucleotides. While CRIS...

  11. Experimental analysis of oligonucleotide microarray design criteria to detect deletions by comparative genomic hybridization

    Directory of Open Access Journals (Sweden)

    Moerman Donald G


    Full Text Available Abstract Background Microarray comparative genomic hybridization (CGH is currently one of the most powerful techniques to measure DNA copy number in large genomes. In humans, microarray CGH is widely used to assess copy number variants in healthy individuals and copy number aberrations associated with various diseases, syndromes and disease susceptibility. In model organisms such as Caenorhabditis elegans (C. elegans the technique has been applied to detect mutations, primarily deletions, in strains of interest. Although various constraints on oligonucleotide properties have been suggested to minimize non-specific hybridization and improve the data quality, there have been few experimental validations for CGH experiments. For genomic regions where strict design filters would limit the coverage it would also be useful to quantify the expected loss in data quality associated with relaxed design criteria. Results We have quantified the effects of filtering various oligonucleotide properties by measuring the resolving power for detecting deletions in the human and C. elegans genomes using NimbleGen microarrays. Approximately twice as many oligonucleotides are typically required to be affected by a deletion in human DNA samples in order to achieve the same statistical confidence as one would observe for a deletion in C. elegans. Surprisingly, the ability to detect deletions strongly depends on the oligonucleotide 15-mer count, which is defined as the sum of the genomic frequency of all the constituent 15-mers within the oligonucleotide. A similarity level above 80% to non-target sequences over the length of the probe produces significant cross-hybridization. We recommend the use of a fairly large melting temperature window of up to 10°C, the elimination of repeat sequences, the elimination of homopolymers longer than 5 nucleotides, and a threshold of -1 kcal/mol on the oligonucleotide self-folding energy. We observed very little difference in data

  12. Efficient gene silencing by delivery of locked nucleic acid antisense oligonucleotides, unassisted by transfection reagents. (United States)

    Stein, C A; Hansen, J Bo; Lai, Johnathan; Wu, SiJian; Voskresenskiy, Anatoliy; Høg, Anja; Worm, Jesper; Hedtjärn, Maj; Souleimanian, Naira; Miller, Paul; Soifer, Harris S; Castanotto, Daniella; Benimetskaya, Luba; Ørum, Henrik; Koch, Troels


    For the past 15-20 years, the intracellular delivery and silencing activity of oligodeoxynucleotides have been essentially completely dependent on the use of a delivery technology (e.g. lipofection). We have developed a method (called 'gymnosis') that does not require the use of any transfection reagent or any additives to serum whatsoever, but rather takes advantage of the normal growth properties of cells in tissue culture in order to promote productive oligonucleotide uptake. This robust method permits the sequence-specific silencing of multiple targets in a large number of cell types in tissue culture, both at the protein and mRNA level, at concentrations in the low micromolar range. Optimum results were obtained with locked nucleic acid (LNA) phosphorothioate gap-mers. By appropriate manipulation of oligonucleotide dosing, this silencing can be continuously maintained with little or no toxicity for >240 days. High levels of oligonucleotide in the cell nucleus are not a requirement for gene silencing, contrary to long accepted dogma. In addition, gymnotic delivery can efficiently deliver oligonucleotides to suspension cells that are known to be very difficult to transfect. Finally, the pattern of gene silencing of in vitro gymnotically delivered oligonucleotides correlates particularly well with in vivo silencing. The establishment of this link is of particular significance to those in the academic research and drug discovery and development communities.

  13. Novel Efficient Cell-Penetrating, Peptide-Mediated Strategy for Enhancing Telomerase Inhibitor Oligonucleotides. (United States)

    Muñoz-Alarcón, Andrés; Eriksson, Jonas; Langel, Ülo


    At present, there are several therapeutic approaches for targeting telomerase in tumors. One in particular, currently undergoing clinical trials, is based on synthetic lipid-modified oligonucleotide antagonists aimed at inhibiting the ribonucleoprotein subunit of human telomerase. However, while enabling efficient uptake, the lipid modifications reduce the potency of the therapeutic oligonucleotides compared to nonmodified oligonucleotides. Moreover, lipid modification may increase oligonucleotide accumulation in the liver causing undesirable hepatotoxicity. Noncovalent complexation strategies for cell-penetrating peptide (CPP)-mediated delivery present an option to circumvent the need for potency-reducing modifications, while allowing for a highly efficient uptake, and could significantly improve the efficiency of telomerase-targeting cancer therapeutics. Delivery of a nonlipidated locked nucleic acid/2'-O-methyl mixmer significantly inhibits the telomerase activity in treated HeLa cells. The inhibitory effect was further improved through addition of a CPP. Furthermore, calculated IC50-values for the oligonucleotide delivered by CPPs into HeLa cells are more than 20 times lower than telomerase inhibitor Imetelstat, currently undergoing clinical trials. These results emphasize the potential of CPP-mediated delivery of future pharmaceuticals and provide means by which to enhance an already promising therapeutic strategy for cancer treatment.

  14. Conjugates of Phthalocyanines With Oligonucleotides as Reagents for Sensitized or Catalytic DNA Modification

    Directory of Open Access Journals (Sweden)


    Full Text Available Several conjugates of metallophthalocyanines with deoxyribooligonucleotides were synthesized to investigate sequence-specific modification of DNA by them. Oligonucleotide parts of these conjugates were responsible for the recognition of selected complementary sequences on the DNA target. Metallophthalocyanines were able to induce the DNA modification: phthalocyanines of Zn(II and Al(III were active as photosensitizers in the generation of singlet oxygen 1 O 2 , while phthalocyanine of Co(II promoted DNA oxidation by molecular oxygen through the catalysis of formation of reactive oxygen species ( ⋅ O 2 − , O 2 H 2 , OH. Irradiation of the reaction mixture containing either Zn(II- or Al(III-tetracarboxyphthalocyanine conjugates of oligonucleotide pd(TCTTCCCA with light of > 340 nm wavelength (Hg lamp or He/Ne laser resulted in the modification of the 22-nucleotide target d(TGAATGGGAAGAGGGTCAGGTT. A conjugate of Co(II-tetracarboxyphthalocyanine with the oligonucleotide was found to modify the DNA target in the presence of O 2 and 2-mercaptoethanol or in the presence of O 2 H 2 . Under both sensitized and catalyzed conditions, the nucleotides G 13 – G 15 were mainly modified, providing evidence that the reaction proceeded in the double-stranded oligonucleotide. These results suggest the possible use of phthalocyanine-oligonucleotide conjugates as novel artificial regulators of gene expression and therapeutic agents for treatment of cancer.

  15. Oligonucleotide-induced alternative splicing of serotonin 2C receptor reduces food intake. (United States)

    Zhang, Zhaiyi; Shen, Manli; Gresch, Paul J; Ghamari-Langroudi, Masoud; Rabchevsky, Alexander G; Emeson, Ronald B; Stamm, Stefan


    The serotonin 2C receptor regulates food uptake, and its activity is regulated by alternative pre-mRNA splicing. Alternative exon skipping is predicted to generate a truncated receptor protein isoform, whose existence was confirmed with a new antiserum. The truncated receptor sequesters the full-length receptor in intracellular membranes. We developed an oligonucleotide that promotes exon inclusion, which increases the ratio of the full-length to truncated receptor protein. Decreasing the amount of truncated receptor results in the accumulation of full-length, constitutively active receptor at the cell surface. After injection into the third ventricle of mice, the oligonucleotide accumulates in the arcuate nucleus, where it changes alternative splicing of the serotonin 2C receptor and increases pro-opiomelanocortin expression. Oligonucleotide injection reduced food intake in both wild-type and ob/ob mice. Unexpectedly, the oligonucleotide crossed the blood-brain barrier and its systemic delivery reduced food intake in wild-type mice. The physiological effect of the oligonucleotide suggests that a truncated splice variant regulates the activity of the serotonin 2C receptor, indicating that therapies aimed to change pre-mRNA processing could be useful to treat hyperphagia, characteristic for disorders like Prader-Willi syndrome.

  16. A facile inhibitor screening of SARS coronavirus N protein using nanoparticle-based RNA oligonucleotide

    Directory of Open Access Journals (Sweden)

    Roh C


    Full Text Available Changhyun RohDivision of Biotechnology, Advanced Radiation Technology Institute (ARTI, Korea Atomic Energy Research Institute (KAERI, Jeongeup, Republic of KoreaAbstract: Hundreds of million people worldwide have been infected with severe acute respiratory syndrome (SARS, and the rate of global death from SARS has remarkably increased. Hence, the development of efficient drug treatments for the biological effects of SARS is highly needed. We have previously shown that quantum dots (QDs-conjugated RNA oligonucleotide is sensitive to the specific recognition of the SARS-associated coronavirus (SARS-CoV nucleocapsid (N protein. In this study, we found that a designed biochip could analyze inhibitors of the SARS-CoV N protein using nanoparticle-based RNA oligonucleotide. Among the polyphenolic compounds examined, (--catechin gallate and (--gallocatechin gallate demonstrated a remarkable inhibition activity on SARS-CoV N protein. (--catechin gallate and (--gallocatechin gallate attenuated the binding affinity in a concentrated manner as evidenced by QDs-conjugated RNA oligonucleotide on a designed biochip. At a concentration of 0.05 µg mL–1, (--catechin gallate and (--gallocatechin gallate showed more than 40% inhibition activity on a nanoparticle-based RNA oligonucleotide biochip system.Keywords: SARS, RNA oligonucleotide, quantum dots, inhibitor, screening

  17. Aspects of oligonucleotide and peptide sequencing with MALDI and electrospray mass spectrometry. (United States)

    Owens, D R; Bothner, B; Phung, Q; Harris, K; Siuzdak, G


    Biopolymer sequencing with mass spectrometry has become increasingly important and accessible with the development of matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI). Here we examine the use of sequential digestion for the rapid identification of proteolytic fragments, in turn highlighting the general utility of enzymatic MALDI ladder sequencing and ESI tandem mass spectrometry. Analyses were performed on oligonucleotides ranging in size from 2 to 50 residues, on peptides ranging in size from 7 to 44 residues and on viral coat proteins. MALDI ladder sequencing using exonuclease digestion generated a uniform distribution of ions and provided complete sequence information on the oligonucleotides 2-30 nucleic acid residues long. Only partial sequence information was obtained on the longer oligonucleotides. C-terminal peptide ladder sequencing typically provided information from 4 to 7 amino acids into the peptide. Sequential digestion, or endoprotease followed by exoprotease exposure, was also successfully applied to a trypsin digest of viral proteins. Analysis of ladder sequenced peptides by LCMS generated less information than in the MALDI-MS analysis and ESI-MS2 normally provided partial sequence information on both the small oligonucleotides and peptides. In general, MALDI ladder sequencing offered information on a broader mass range of biopolymers than ESI-MS2 and was relatively straightforward to interpret, especially for oligonucleotides.

  18. LNA-modified isothermal oligonucleotide microarray for differentiating bacilli of similar origin

    Indian Academy of Sciences (India)

    Jing Yan; Ying Yuan; Runqing Mu; Hong Shang; Yifu Guan


    Oligonucleotide microarray has been one of the most powerful tools in the ‘Post-Genome Era’ for its high sensitivity, high throughput and parallel processing capability. To achieve high detection specificity, we fabricated an isothermal microarray using locked nucleic acid (LNA)-modified oligonucleotide probes, since LNA has demonstrated the advanced ability to enhance the binding affinity toward their complementary nucleotides. After designing the nucleotide sequences of these oligonucleotide probes for gram-positive bacilli of similar origin (Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus megaterium and Bacillus circulans), we unified the melting temperatures of these oligonucleotide probes by modifying some nucleotides using LNA. Furthermore, we optimized the experimental procedures of hydrating microarray slides, blocking side surface as well as labelling the PCR products. Experimental results revealed that KOD Dash DNA polymerase could efficiently incorporate Cy3-dCTP into the PCR products, and the LNA-isothermal oligonucleotide microarray were able to distinguish the bacilli of similar origin with a high degree of accuracy and specificity under the optimized experimental condition.

  19. Combined in vitro transcription and reverse transcription to amplify and label complex synthetic oligonucleotide probe libraries. (United States)

    Murgha, Yusuf; Beliveau, Brian; Semrau, Kassandra; Schwartz, Donald; Wu, Chao-Ting; Gulari, Erdogan; Rouillard, Jean-Marie


    Oligonucleotide microarrays allow the production of complex custom oligonucleotide libraries for nucleic acid detection-based applications such as fluorescence in situ hybridization (FISH). We have developed a PCR-free method to make single-stranded DNA (ssDNA) fluorescent probes through an intermediate RNA library. A double-stranded oligonucleotide library is amplified by transcription to create an RNA library. Next, dye- or hapten-conjugate primers are used to reverse transcribe the RNA to produce a dye-labeled cDNA library. Finally the RNA is hydrolyzed under alkaline conditions to obtain the single-stranded fluorescent probes library. Starting from unique oligonucleotide library constructs, we present two methods to produce single-stranded probe libraries. The two methods differ in the type of reverse transcription (RT) primer, the incorporation of fluorescent dye, and the purification of fluorescent probes. The first method employs dye-labeled reverse transcription primers to produce multiple differentially single-labeled probe subsets from one microarray library. The fluorescent probes are purified from excess primers by oligonucleotide-bead capture. The second method uses an RNA:DNA chimeric primer and amino-modified nucleotides to produce amino-allyl probes. The excess primers and RNA are hydrolyzed under alkaline conditions, followed by probe purification and labeling with amino-reactive dyes. The fluorescent probes created by the combination of transcription and reverse transcription can be used for FISH and to detect any RNA and DNA targets via hybridization.

  20. Efficient oligonucleotide probe selection for pan-genomic tiling arrays

    Directory of Open Access Journals (Sweden)

    Zhang Wei


    Full Text Available Abstract Background Array comparative genomic hybridization is a fast and cost-effective method for detecting, genotyping, and comparing the genomic sequence of unknown bacterial isolates. This method, as with all microarray applications, requires adequate coverage of probes targeting the regions of interest. An unbiased tiling of probes across the entire length of the genome is the most flexible design approach. However, such a whole-genome tiling requires that the genome sequence is known in advance. For the accurate analysis of uncharacterized bacteria, an array must query a fully representative set of sequences from the species' pan-genome. Prior microarrays have included only a single strain per array or the conserved sequences of gene families. These arrays omit potentially important genes and sequence variants from the pan-genome. Results This paper presents a new probe selection algorithm (PanArray that can tile multiple whole genomes using a minimal number of probes. Unlike arrays built on clustered gene families, PanArray uses an unbiased, probe-centric approach that does not rely on annotations, gene clustering, or multi-alignments. Instead, probes are evenly tiled across all sequences of the pan-genome at a consistent level of coverage. To minimize the required number of probes, probes conserved across multiple strains in the pan-genome are selected first, and additional probes are used only where necessary to span polymorphic regions of the genome. The viability of the algorithm is demonstrated by array designs for seven different bacterial pan-genomes and, in particular, the design of a 385,000 probe array that fully tiles the genomes of 20 different Listeria monocytogenes strains with overlapping probes at greater than twofold coverage. Conclusion PanArray is an oligonucleotide probe selection algorithm for tiling multiple genome sequences using a minimal number of probes. It is capable of fully tiling all genomes of a species on

  1. A novel multifunctional oligonucleotide microarray for Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Chen Feng


    Full Text Available Abstract Background Microarrays are invaluable tools for genome interrogation, SNP detection, and expression analysis, among other applications. Such broad capabilities would be of value to many pathogen research communities, although the development and use of genome-scale microarrays is often a costly undertaking. Therefore, effective methods for reducing unnecessary probes while maintaining or expanding functionality would be relevant to many investigators. Results Taking advantage of available genome sequences and annotation for Toxoplasma gondii (a pathogenic parasite responsible for illness in immunocompromised individuals and Plasmodium falciparum (a related parasite responsible for severe human malaria, we designed a single oligonucleotide microarray capable of supporting a wide range of applications at relatively low cost, including genome-wide expression profiling for Toxoplasma, and single-nucleotide polymorphism (SNP-based genotyping of both T. gondii and P. falciparum. Expression profiling of the three clonotypic lineages dominating T. gondii populations in North America and Europe provides a first comprehensive view of the parasite transcriptome, revealing that ~49% of all annotated genes are expressed in parasite tachyzoites (the acutely lytic stage responsible for pathogenesis and 26% of genes are differentially expressed among strains. A novel design utilizing few probes provided high confidence genotyping, used here to resolve recombination points in the clonal progeny of sexual crosses. Recent sequencing of additional T. gondii isolates identifies >620 K new SNPs, including ~11 K that intersect with expression profiling probes, yielding additional markers for genotyping studies, and further validating the utility of a combined expression profiling/genotyping array design. Additional applications facilitating SNP and transcript discovery, alternative statistical methods for quantifying gene expression, etc. are also pursued at

  2. Delivery of antisense oligonucleotide to the cornea by iontophoresis. (United States)

    Berdugo, M; Valamanesh, F; Andrieu, C; Klein, C; Benezra, D; Courtois, Y; Behar-Cohen, F


    We wished to evaluate the potential of iontophoresis to promote the delivery of antisense oligonucleotides (ODN) directed at the vascular endothelial growth factor (VEGF)-R2 receptor (KDR/Flk) to the cornea of the rat eye. Fluorescence (CY5)-labeled ODNs in phosphate-buffered saline (PBS) (20 microM) were locally administered to rat eyes, and their fate within the anterior segment was studied. Thirty-four male, 5-week-old Wistar rats were used for all experiments. The rats were divided in four groups. In group I (12 rats, 12 eyes), the ODNs (20 microM) were delivered by iontophoresis (300 microA for 5 minutes) using a specially designed corneal applicator. In group II (12 rats, 12 eyes), the ODNs (20 microM) were delivered using the same applicator, but no electrical current was applied. In group III (6 rats, 6 eyes), a corneal neovascular reaction was induced prior to the application of ODNs (20 microM), and iontophoresis electrical current was delivered as for group I rats. Group IV (4 rats, 4 eyes) received ODN (60 microM) iontophoresis application (300 microA for 5 minutes) and were used for ODN integrity studies. The animals were killed 5 minutes, 90 minutes, and 24 hours after a single ODN application and studied. Topically applied ODNs using the same iontophoresis applicator but without current do not penetrate the cornea and remain confined to the superficial epithelial layer. ODNs delivered with transcorneoscleral iontophoresis penetrate into all corneal layers and are also detected in the iris. In corneas with neovascularization, ODNs were particularly localized within the vascular endothelial cells of the stroma. ODNs extracted from eye tissues 24 hours after iontophoresis remained unaltered. The iontophoresis current did not cause any detectable ocular damage under these conditions. Iontophoresis promotes the delivery of ODNs to the anterior segment of the eye, including all corneal layers. Iontophoresis of ODNs directed at VEGF-R2 may be used for the

  3. Short locked nucleic acid antisense oligonucleotides potently reduce apolipoprotein B mRNA and serum cholesterol in mice and non-human primates

    DEFF Research Database (Denmark)

    Straarup, Ellen Marie; Fisker, Niels; Hedtjärn, Maj;


    the design of short antisense oligonucleotides (12- to 13-mers) that possessed high affinity and increased potency both in vitro and in vivo compared to longer oligonucleotides. The short LNA oligonucleotides were more target specific, and they exhibited the same biodistribution and tissue half......-high-density lipoprotein (non-HDL) cholesterol without increasing serum liver toxicity markers. The data presented here show that oligonucleotide length as a parameter needs to be considered in the design of antisense oligonucleotide and that potent short oligonucleotides with sufficient target affinity can be generated...

  4. Antisense oligonucleotide induced exon skipping and the dystrophin gene transcript: cocktails and chemistries

    Directory of Open Access Journals (Sweden)

    Fletcher Sue


    Full Text Available Abstract Background Antisense oligonucleotides (AOs can interfere with exon recognition and intron removal during pre-mRNA processing, and induce excision of a targeted exon from the mature gene transcript. AOs have been used in vitro and in vivo to redirect dystrophin pre-mRNA processing in human and animal cells. Targeted exon skipping of selected exons in the dystrophin gene transcript can remove nonsense or frame-shifting mutations that would otherwise have lead to Duchenne Muscular Dystrophy, the most common childhood form of muscle wasting. Results Although many dystrophin exons can be excised using a single AO, several exons require two motifs to be masked for efficient or specific exon skipping. Some AOs were inactive when applied individually, yet pronounced exon excision was induced in transfected cells when the AOs were used in select combinations, clearly indicating synergistic rather than cumulative effects on splicing. The necessity for AO cocktails to induce efficient exon removal was observed with 2 different chemistries, 2'-O-methyl modified bases on a phosphorothioate backbone and phosphorodiamidate morpholino oligomers. Similarly, other trends in exon skipping, as a consequence of 2'-O-methyl AO action, such as removal of additional flanking exons or variations in exon skipping efficiency with overlapping AOs, were also seen when the corresponding sequences were prepared as phosphorodiamidate morpholino oligomers. Conclusion The combination of 2 AOs, directed at appropriate motifs in target exons was found to induce very efficient targeted exon skipping during processing of the dystrophin pre-mRNA. This combinatorial effect is clearly synergistic and is not influenced by the chemistry of the AOs used to induce exon excision. A hierarchy in exon skipping efficiency, observed with overlapping AOs composed of 2'-O-methyl modified bases, was also observed when these same sequences were evaluated as phosphorodiamidate morpholino

  5. Hydration-dependent dynamics of human telomeric oligonucleotides in the picosecond timescale: A neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Sebastiani, F.; Comez, L.; Sacchetti, F. [Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Via A. Pascoli, 06123 Perugia (Italy); CNR, Istituto Officina dei Materiali, Unità di Perugia, c/o Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia (Italy); Longo, M. [Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Via A. Pascoli, 06123 Perugia (Italy); Elettra—Sincrotrone Trieste, 34149 Basovizza, Trieste (Italy); Orecchini, A.; Petrillo, C.; Paciaroni, A., E-mail: [Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Via A. Pascoli, 06123 Perugia (Italy); De Francesco, A. [CNR-IOM OGG c/o Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9 (France); Muthmann, M. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at Heinz Maier-Leibnitz Zentrum, Lichtenbergstrasse 1, 85747 Garching (Germany); Teixeira, S. C. M. [EPSAM, Keele University, Staffordshire ST5 5BG (United Kingdom); Institut Laue–Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9 (France)


    The dynamics of the human oligonucleotide AG{sub 3}(T{sub 2}AG{sub 3}){sub 3} has been investigated by incoherent neutron scattering in the sub-nanosecond timescale. A hydration-dependent dynamical activation of thermal fluctuations in weakly hydrated samples was found, similar to that of protein powders. The amplitudes of such thermal fluctuations were evaluated in two different exchanged wave-vector ranges, so as to single out the different contributions from intra- and inter-nucleotide dynamics. The activation energy was calculated from the temperature-dependent characteristic times of the corresponding dynamical processes. The trends of both amplitudes and activation energies support a picture where oligonucleotides possess a larger conformational flexibility than long DNA sequences. This additional flexibility, which likely results from a significant relative chain-end contribution to the average chain dynamics, could be related to the strong structural polymorphism of the investigated oligonucleotides.

  6. Kinetic effects on signal normalization in oligonucleotide microchips with labeled immobilized probes. (United States)

    Pan'kov, S V; Chechetkin, V R; Somova, O G; Antonova, O V; Moiseeva, O V; Prokopenko, D V; Yurasov, R A; Gryadunov, D A; Chudinov, A V


    Among various factors affecting operation of oligonucleotide microchips, the variations in concentration and in homogeneous distribution of immobilized probes over the cells are one of the most important. The labeling of immobilized probes ensures the complete current monitoring on the probe distribution and is reliable and convenient. Using hydrogel-based oligonucleotide microchips, the applicability of Cy3-labeled immobilized probes for quality control and signal normalization after hybridization with Cy5-labeled target DNA was investigated. This study showed that proper signal normalization should be different in thermodynamic conditions and in transient regime with hybridization far from saturation. This kinetic effect holds for both hydrogel-based and surface oligonucleotide microchips. Besides proving basic features, the technique was assessed on a sampling batch of 50 microchips developed for identifying mutations responsible for rifampicin and isoniazid resistance of Mycobacterium tuberculosis.

  7. Repair of Thalassemic Human β -globin mRNA in Mammalian Cells by Antisense Oligonucleotides (United States)

    Sierakowska, Halina; Sambade, Maria J.; Agrawal, Sudhir; Kole, Ryszard


    In one form of β -thalassemia, a genetic blood disorder, a mutation in intron 2 of the β -globin gene (IVS2-654) causes aberrant splicing of β -globin pre-mRNA and, consequently, β -globin deficiency. Treatment of mammalian cells stably expressing the IVS2-654 human β -globin gene with antisense oligonucleotides targeted at the aberrant splice sites restored correct splicing in a dose-dependent fashion, generating correct human β -globin mRNA and polypeptide. Both products persisted for up to 72 hr posttreatment. The oligonucleotides modified splicing by a true antisense mechanism without overt unspecific effects on cell growth and splicing of other pre-mRNAs. This novel approach in which antisense oligonucleotides are used to restore rather than to down-regulate the activity of the target gene is applicable to other splicing mutants and is of potential clinical interest.

  8. Dynamics of human telomerase RNA structure revealed by antisense oligonucleotide technique. (United States)

    Vasilkova, Daria V; Azhibek, Dulat M; Zatsepin, Timofei S; Naraikina, Yulia V; Prassolov, Vladimir S; Prokofjeva, Maria M; Zvereva, Maria I; Rubtsova, Maria P


    Telomeres are the nucleoprotein complexes that cap the linear chromosome ends. Telomerase is a ribonucleoprotein that maintains telomere length in stem, embryonic and cancer cells. Somatic cells don't contain active telomerase and telomere function as mitotic clock and telomere length determines the number of cell divisions. Telomerase RNA (TER) contains the template for telomere synthesis and serves as a structural scaffold for holoenzyme assembly. We compared different oligonucleotide based methods for telomerase RNA inhibition, such as antisense oligonucleotides, knockdown by transient siRNA transfection and silencing by miRNA derived from short expressed RNA hairpin in HEK293 cells. All of these methods were applied to different TER regions. Our results revealed that CR2/CR3 domain of TER is accessible in vitro and in vivo and could serve as an optimal site for oligonucleotide-based telomerase silencing.

  9. Use of thiolated oligonucleotides as anti-fouling diluents in electrochemical peptide-based sensors. (United States)

    McQuistan, Adam; Zaitouna, Anita J; Echeverria, Elena; Lai, Rebecca Y


    We incorporated short thiolated oligonucleotides as passivating diluents in the fabrication of electrochemical peptide-based (E-PB) sensors, with the goal of creating a negatively charged layer capable of resisting non-specific adsorption of matrix contaminants. The E-PB HIV sensors fabricated using these diluents were found to be more specific and selective, while retaining attributes similar to the sensor fabricated without these diluents. Overall, these results highlight the advantages of using oligonucleotides as anti-fouling diluents in self-assembled monolayer-based sensors.

  10. Transcriptional inhibition of the bacteriophage T7 early promoter region by oligonucleotide triple helix formation. (United States)

    Ross, C; Samuel, M; Broitman, S L


    We have identified a purine-rich triplex binding sequence overlapping a -35 transcriptional early promoter region of the bacteriophage T7. Triplex-forming oligonucleotide designed to bind this target was annealed to T7 templates and introduced into in vitro transcription systems under conditions favoring specific initiation from this promoter. These templates demonstrated significant transcriptional inhibition relative to naked genomic templates and templates mixed with non-triplex-forming oligonucleotide. It is suggested that triplex formation along this target interferes with transcriptional initiation, and this mechanism may hold potential to disrupt bacteriophage T7 early transcription in vivo.

  11. Customized oligonucleotide microchips that convert multiple genetic information to simple patterns, are portable and reusable (United States)

    Mirzabekov, Andrei; Guschin, Dmitry Y.; Chik, Valentine; Drobyshev, Aleksei; Fotin, Alexander; Yershov, Gennadiy; Lysov, Yuri


    This invention relates to using customized oligonucleotide microchips as biosensors for the detection and identification of nucleic acids specific for different genes, organisms and/or individuals in the environment, in food and in biological samples. The microchips are designed to convert multiple bits of genetic information into simpler patterns of signals that are interpreted as a unit. Because of an improved method of hybridizing oligonucleotides from samples to microchips, microchips are reusable and transportable. For field study, portable laser or bar code scanners are suitable.

  12. Oligonucleotide-templated chemical reactions: pushing the boundaries of a nature-inspired process. (United States)

    Percivalle, Claudia; Bartolo, Jean-François; Ladame, Sylvain


    Widespread in nature, oligonucleotide-templated reactions of phosphodiester bond formation have inspired chemists who are now applying this elegant strategy to the catalysis of a broad range of otherwise inefficient reactions. This review highlights the increasing diversity of chemical reactions that can be efficiently catalysed by an oligonucleotide template, using Watson-Crick base-pairing to bring both reagents in close enough proximity to react, thus increasing significantly their effective molarity. The applications of this elegant concept for nucleic acid sensing and controlled organic synthesis will also be discussed.

  13. Sequence selective naked-eye detection of DNA harnessing extension of oligonucleotide-modified nucleotides. (United States)

    Verga, Daniela; Welter, Moritz; Marx, Andreas


    DNA polymerases can efficiently and sequence selectively incorporate oligonucleotide (ODN)-modified nucleotides and the incorporated oligonucleotide strand can be employed as primer in rolling circle amplification (RCA). The effective amplification of the DNA primer by Φ29 DNA polymerase allows the sequence-selective hybridisation of the amplified strand with a G-quadruplex DNA sequence that has horse radish peroxidase-like activity. Based on these findings we develop a system that allows DNA detection with single-base resolution by naked eye.

  14. Gaseous abundances in M82

    CERN Document Server

    Ranalli, P; Origlia, L; Maiolino, R; Makishima, K; Ranalli, Piero; Comastri, Andrea; Origlia, Livia; Maiolino, Roberto; Makishima, Kazuo


    We present the preliminary analysis of a deep (100ks) XMM-Newton observation of M82. The spatial distribution of the abundances of chemical elements (Fe, O, Ne, Mg, Si, S) is investigated through narrow-band imaging analisys and spatially-resolved spectroscopy. We find that the abundances of alpha-elements follow a bipolar distribution, these elements being more abundant in the gaseous outflow than in the galaxy centre. This behaviour is found to be more marked for lighter elements (O, Ne) than for heavier elements.

  15. Can occupancy-abundance models be used to monitor wolf abundance?

    Directory of Open Access Journals (Sweden)

    M Cecilia Latham

    Full Text Available Estimating the abundance of wild carnivores is of foremost importance for conservation and management. However, given their elusive habits, direct observations of these animals are difficult to obtain, so abundance is more commonly estimated from sign surveys or radio-marked individuals. These methods can be costly and difficult, particularly in large areas with heavy forest cover. As an alternative, recent research has suggested that wolf abundance can be estimated from occupancy-abundance curves derived from "virtual" surveys of simulated wolf track networks. Although potentially more cost-effective, the utility of this approach hinges on its robustness to violations of its assumptions. We assessed the sensitivity of the occupancy-abundance approach to four assumptions: variation in wolf movement rates, changes in pack cohesion, presence of lone wolves, and size of survey units. Our simulations showed that occupancy rates and wolf pack abundances were biased high if track surveys were conducted when wolves made long compared to short movements, wolf packs were moving as multiple hunting units as opposed to a cohesive pack, and lone wolves were moving throughout the surveyed landscape. We also found that larger survey units (400 and 576 km2 were more robust to changes in these factors than smaller survey units (36 and 144 km2. However, occupancy rates derived from large survey units rapidly reached an asymptote at 100% occupancy, suggesting that these large units are inappropriate for areas with moderate to high wolf densities (>15 wolves/1,000 km2. Virtually-derived occupancy-abundance relationships can be a useful method for monitoring wolves and other elusive wildlife if applied within certain constraints, in particular biological knowledge of the surveyed species needs to be incorporated into the design of the occupancy surveys. Further, we suggest that the applicability of this method could be extended by directly incorporating some of its

  16. Non-additive effects of genotypic diversity increase floral abundance and abundance of floral visitors.

    Directory of Open Access Journals (Sweden)

    Mark A Genung

    Full Text Available BACKGROUND: In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. METHODOLOGY/PRINCIPAL FINDINGS: Using an experimental common garden that manipulated genotypic diversity (the number of distinct genotypes per plot of Solidago altissima, we document that genotypic diversity of a dominant plant can indirectly influence flower visitor abundance. Across two years, we found that 1 plant genotype explained 45% and 92% of the variation in flower visitor abundance in 2007 and 2008, respectively; and 2 plant genotypic diversity had a positive and non-additive effect on floral abundance and the abundance of flower visitors, as plots established with multiple genotypes produced 25% more flowers and received 45% more flower visits than would be expected under an additive model. CONCLUSIONS/SIGNIFICANCE: These results provide evidence that declines in genotypic diversity may be an important but little considered factor for understanding plant-pollinator dynamics, with implications for the global decline in pollinators due to reduced plant diversity in both agricultural and natural ecosystems.

  17. Studies on the Syntheses and Properties of 5'-Branched-sugar Isonucleosides and the Related Oligonucleotides

    Institute of Scientific and Technical Information of China (English)

    TianXiaobing; ZhangLihe; MinJimei


    The chemistry of nucleosides and oligonucleotides is an actively investigated field in the search for new drugs. Thesyntheses and the properties of isonucleosides and oligonucleotides have been investigated to improve their stability,antitumor and antiviral activities, and to reduce their toxicity.

  18. Synthesis, Dynamic Combinatorial Chemistry, and PCR Amplification of 3'-5' and 3'-6' Disulfide-linked Oligonucleotides

    DEFF Research Database (Denmark)

    Hansen, Dennis Jul; Manuguerra, Ilenia; Kjelstrup, Michael Brøndum;


    Disulfide dithymidines linked 3'-5' or 3'-6' were synthesized and incorporated into oligonucleotides through a combined phosphotriester and phosphoramidite solid-phase oligonucleotide synthesis approach. The disulfide links are cleaved and formed reversibly in the presence of thiols and oligonucl...

  19. Oligonucleotides Containing Aminated 2'-Amino-LNA Nucleotides: Synthesis and Strong Binding to Complementary DNA and RNA. (United States)

    Lou, Chenguang; Samuelsen, Simone V; Christensen, Niels Johan; Vester, Birte; Wengel, Jesper


    Mono- and diaminated 2'-amino-LNA monomers were synthesized and introduced into oligonucleotides. Each modification imparts significant stabilization of nucleic acid duplexes and triplexes, excellent sequence selectivity, and significant nuclease resistance. Molecular modeling suggested that structural stabilization occurs via intrastrand electrostatic attraction between the protonated amino groups of the aminated 2'-amino-LNA monomers and the host oligonucleotide backbone.

  20. Chlorine Abundances in Cool Stars

    CERN Document Server

    Maas, Z G; Hinkle, K


    Chlorine abundances are reported in 15 evolved giants and one M dwarf in the solar neighborhood. The Cl abundance was measured using the vibration-rotation 1-0 P8 line of H$^{35}$Cl at 3.69851 $\\mu$m. The high resolution L-band spectra were observed using the Phoenix infrared spectrometer on the Kitt Peak Mayall 4m telescope. The average [$^{35}$Cl/Fe] abundance in stars with --0.72$<$[Fe/H]$<$0.20 is [$^{35}$Cl/Fe]=(--0.10$\\pm$0.15) dex. The mean difference between the [$^{35}$Cl/Fe] ratios measured in our stars and chemical evolution model values is (0.16$\\pm$0.15) dex. The [$^{35}$Cl/Ca] ratio has an offset of $\\sim$0.35 dex above model predictions suggesting chemical evolution models are under producing Cl at the high metallicity range. Abundances of C, N, O, Si, and Ca were also measured in our spectral region and are consistent with F and G dwarfs. The Cl versus O abundances from our sample match Cl abundances measured in planetary nebula and \\ion{H}{2} regions. In one star where both H$^{35}$Cl a...

  1. A triple-helix forming oligonucleotide targeting genomic DNA fails to induce mutation. (United States)

    Reshat, Reshat; Priestley, Catherine C; Gooderham, Nigel J


    Purine tracts in duplex DNA can bind oligonucleotide strands in a sequence specific manner to form triple-helix structures. Triple-helix forming oligonucleotides (TFOs) targeting supFG1 constructs have previously been shown to be mutagenic raising safety concerns for oligonucleotide-based pharmaceuticals. We have engineered a TFO, TFO27, to target the genomic Hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus to define the mutagenic potential of such structures at genomic DNA. We report that TFO27 was resistant to nuclease degradation and readily binds to its target motif in a cell free system. Contrary to previous studies using the supFG1 reporter construct, TFO27 failed to induce mutation within the genomic HPRT locus. We suggest that it is possible that previous reports of triplex-mediated mutation using the supFG1 reporter construct could be confounded by DNA quadruplex formation. Although the present study indicates that a TFO targeting a genomic locus lacks mutagenic activity, it is unclear if this finding can be generalised to all TFOs and their targets. For the present, we suggest that it is prudent to avoid large purine stretches in oligonucleotide pharmaceutical design to minimise concern regarding off-target genotoxicity.

  2. Effect of iontophoresis on the in vitro trans-scleral transport of three single stranded oligonucleotides. (United States)

    Pescina, Silvia; Antopolsky, Maxim; Santi, Patrizia; Nicoli, Sara; Murtomäki, Lasse


    Oligonucleotides represent a subject of clinical interest due to their potential ability to treat several diseases, including those affecting the posterior segment of the eye. Unfortunately, therapeutic oligonucleotides are currently administered by means of highly invasive approaches, such as intravitreal injections. The aim of the present work was to study in vitro, across isolated bovine sclera, the effect of iontophoresis on the transport of three single stranded oligonucleotides (ssDNA), 12-, 24- and 36-mer, selected as reference compounds in view of a non-invasive drug delivery to the back of the eye. All the three sequences were able to cross bovine sclera in vitro without iontophoresis. When anodal iontophoresis was applied, no change in flux was observed, while in the presence of cathodal iontophoresis the permeability coefficients increased four-fold compared to passive conditions. This behavior can be ascribed to the electrorepulsive mechanism, due to the negative charge of the nucleic acid backbone. It was also observed that the molecular weights of the three sequences did not affect trans-scleral transport, neither in passive, nor in current assisted permeation. Furthermore, increasing the current intensity from 1.75 mA to 3 mA, no effect on the trans-scleral transport of the 24-mer was noticed. Although preliminary, the results demonstrate that cathodal iontophoresis enhances trans-scleral transport of single stranded oligonucleotides and suggest its use as a novel non-invasive approach for the treatment of diseases affecting the posterior segment of the eye.

  3. In situ entry of oligonucleotides into brain cells can occur through a nucleic acid channel

    NARCIS (Netherlands)

    Shi, Fuxin; Gounko, Natasha V.; Wang, Xiaoqin; Ronken, Eric; Hoekstra, Dick


    Brain tissue has become a challenging therapeutic target, in part because of failure of conventional treatments of brain tumors and a gradually increasing number of neurodegenerative diseases. Because antisense oligonucleotides are readily internalized by neuronal cells in culture, these compounds c

  4. A new achiral reagent for the incorporation of multiple amino groups into oligonucleotides

    DEFF Research Database (Denmark)

    Behrens, Carsten; Petersen, Kenneth H.; Egholm, Michael;


    The synthesis of a new functionalized achiral linker reagent (10) for the incorporation of multiple primary amino groups into oligonucleotides is described. The linker reagent is compatible with conventional DNA-synthesis following the phosphoramidite methodology, and the linker can be incorporat...

  5. Application of decoy oligonucleotides as novel therapeutic strategy: a contemporary overview. (United States)

    Ahmad, Mohammad Zaki; Akhter, Sohail; Mallik, Neha; Anwar, Mohammad; Tabassum, Wajda; Ahmad, Farhan Jalees


    Molecular therapy is emerging as a potential strategy for the treatment of many diseases. Correct regulation of gene expression is essential for both, to normal development and proper functioning of the all the organisms. Even after four decades of intensive research, it is still a major problem from regulatory and technical point of view, to replace defective genes. The technology of decoy oligonucleotides has received considerable attention to treat and cure a variety of diseases and abnormal physiological conditions, because they provide a rational way to design and selective regulation of a specific gene expression. Decoy oligonucleotides are widely used as inhibitors of specific gene expression because they can offer exciting possibility of expression and blocking of a particular gene without any changes in the functions of other genes. Advances in the decoy oligonucleotides are rapidly paving the way to new insights into the origin and treatment of inflammatory, cancer and/or other immune disorders. The review covers the progress achieved towards the development of decoy oligonucleotides as a potential strategy in a new class of molecular therapy.

  6. High-frequency genome editing using ssDNA oligonucleotides with zinc-finger nucleases

    DEFF Research Database (Denmark)

    Chen, Fuqiang; Pruett-Miller, Shondra M; Huang, Yuping


    Zinc-finger nucleases (ZFNs) have enabled highly efficient gene targeting in multiple cell types and organisms. Here we describe methods for using simple ssDNA oligonucleotides in tandem with ZFNs to efficiently produce human cell lines with three distinct genetic outcomes: (i) targeted point...

  7. Pd0-Catalyzed Methyl Transfer on Nucleosides and Oligonucleotides, Envisaged as a PET Tracer

    Directory of Open Access Journals (Sweden)

    Eric Fouquet


    Full Text Available The methyl transfer reaction from activated monomethyltin, via a modified Stille coupling reaction, was studied under “ligandless” conditions on fully deprotected 5'-modified nucleosides and one dinucleotide. The reaction was optimized to proceed in a few minutes and quantitative yield, even under dilute conditions, thus affording a rapid and efficient new method for oligonucleotide labelling with carbon-11.

  8. Refinement of antisense oligonucleotide mediated exon skipping as therapy for Duchenne muscular dystrophy

    NARCIS (Netherlands)

    Heemskerk, Johannes Antonius


    In recent years, modulation of mRNA has emerged as a promising therapeutic tool. For instance, in the field of neuromuscular disorders therapeutic strategies are being developed for several diseases, including antisense oligonucleotide (AON) mediated exon skipping for Duchenne Muscular Dystrophy (DM

  9. Stable gene targeting in human cells using single-strand oligonucleotides with modified bases.

    Directory of Open Access Journals (Sweden)

    Xavier Rios

    Full Text Available Recent advances allow multiplexed genome engineering in E. coli, employing easily designed oligonucleotides to edit multiple loci simultaneously. A similar technology in human cells would greatly expedite functional genomics, both by enhancing our ability to test how individual variants such as single nucleotide polymorphisms (SNPs are related to specific phenotypes, and potentially allowing simultaneous mutation of multiple loci. However, oligo-mediated targeting of human cells is currently limited by low targeting efficiencies and low survival of modified cells. Using a HeLa-based EGFP-rescue reporter system we show that use of modified base analogs can increase targeting efficiency, in part by avoiding the mismatch repair machinery. We investigate the effects of oligonucleotide toxicity and find a strong correlation between the number of phosphorothioate bonds and toxicity. Stably EGFP-corrected cells were generated at a frequency of ~0.05% with an optimized oligonucleotide design combining modified bases and reduced number of phosphorothioate bonds. We provide evidence from comparative RNA-seq analysis suggesting cellular immunity induced by the oligonucleotides might contribute to the low viability of oligo-corrected cells. Further optimization of this method should allow rapid and scalable genome engineering in human cells.

  10. Optimization of single-base-pair mismatch discrimination in oligonucleotide microarrays

    NARCIS (Netherlands)

    Urakawa, H.; Fantroussi, El S.; Smidt, H.; Smoot, J.C.; Tribou, E.H.; Kelly, J.J.; Noble, P.A.; Stahl, D.A.


    The discrimination between perfect-match and single-base-pair-mismatched nucleic acid duplexes was investigated by using oligonucleotide DNA microarrays and nonequilibrium dissociation rates (melting profiles). DNA and RNA versions of two synthetic targets corresponding to the 16S rRNA sequences of

  11. Cellular Internalization of Therapeutic Oligonucleotides by Peptide Amphiphile Nanofibers and Nanospheres. (United States)

    Mumcuoglu, Didem; Sardan Ekiz, Melis; Gunay, Gokhan; Tekinay, Turgay; Tekinay, Ayse B; Guler, Mustafa O


    Oligonucleotides are promising drug candidates due to the exceptionally high specificity they exhibit toward their target DNA and RNA sequences. However, their poor pharmacokinetic and pharmacodynamic properties, in conjunction with problems associated with their internalization by cells, necessitates their delivery through specialized carrier systems for efficient therapy. Here, we investigate the effects of carrier morphology on the cellular internalization mechanisms of oligonucleotides by using self-assembled fibrous or spherical peptide nanostructures. Size and geometry were both found to be important parameters for the oligonucleotide internalization process; direct penetration was determined to be the major mechanism for the internalization of nanosphere carriers, whereas nanofibers were internalized by clathrin- and dynamin-dependent endocytosis pathways. We further showed that glucose conjugation to carrier nanosystems improved cellular internalization in cancer cells due to the enhanced glucose metabolism associated with oncogenesis, and the internalization of the glucose-conjugated peptide/oligonucleotide complexes was found to be dependent on glucose transporters present on the surface of the cell membrane.

  12. Methods for the preparation of large quantities of complex single-stranded oligonucleotide libraries. (United States)

    Murgha, Yusuf E; Rouillard, Jean-Marie; Gulari, Erdogan


    Custom-defined oligonucleotide collections have a broad range of applications in fields of synthetic biology, targeted sequencing, and cytogenetics. Also, they are used to encode information for technologies like RNA interference, protein engineering and DNA-encoded libraries. High-throughput parallel DNA synthesis technologies developed for the manufacture of DNA microarrays can produce libraries of large numbers of different oligonucleotides, but in very limited amounts. Here, we compare three approaches to prepare large quantities of single-stranded oligonucleotide libraries derived from microarray synthesized collections. The first approach, alkaline melting of double-stranded PCR amplified libraries with a biotinylated strand captured on streptavidin coated magnetic beads results in little or no non-biotinylated ssDNA. The second method wherein the phosphorylated strand of PCR amplified libraries is nucleolyticaly hydrolyzed is recommended when small amounts of libraries are needed. The third method combining in vitro transcription of PCR amplified libraries to reverse transcription of the RNA product into single-stranded cDNA is our recommended method to produce large amounts of oligonucleotide libraries. Finally, we propose a method to remove any primer binding sequences introduced during library amplification.

  13. Precise construction of oligonucleotide-Fab fragment conjugate for homogeneous immunoassay using HaloTag technology. (United States)

    Päkkilä, Henna; Peltomaa, Riikka; Lamminmäki, Urpo; Soukka, Tero


    The use of oligonucleotide-protein conjugates enables the development of novel types of bioanalytical assays. However, convenient methods for producing covalent and stoichiometric oligonucleotide-protein conjugates are still rare. Here we demonstrate, for the first time, covalent conjugation of DNA oligonucleotide to Fab fragments with a 1:1 ratio using HaloTag self-labeling technology. The oligonucleotide coupling was carried out while the Fab was attached to protein G matrix, thereby enabling straightforward production of covalent conjugates. Furthermore, it allowed convenient purification of the product because the unreacted components were easily removed before the elution of the high-purity conjugate. The prepared conjugate was employed in a homogeneous immunoassay where prostate-specific antigen was used as a model analyte. Switchable lanthanide luminescence was used for detection, and the obtained limit of detection was 0.27 ng/ml. In the future, the developed method for covalent conjugation and successive purification in protein G column could also be applied for introducing other kinds of modifications to Fab fragments in a simple and site-specific manner.

  14. Rapid identification of bacteria in blood cultures by using fluorescently labeled oligonucleotide probes

    NARCIS (Netherlands)

    Jansen, GJ; Mooibroek, M; Idema, J; Harmsen, HJM; Welling, GW; Degener, JE


    The applicability of whole-cell hybridization for the identification of pathogenic bacteria in blood from septic patients was examined. Oligonucleotide probes, fluorescently labeled with fluorescein isothiocyanate, directed against the variable regions of the 16S rRNAs of the following bacterial spe

  15. PCSK9 LNA antisense oligonucleotides induce sustained reduction of LDL cholesterol in nonhuman primates. (United States)

    Lindholm, Marie W; Elmén, Joacim; Fisker, Niels; Hansen, Henrik F; Persson, Robert; Møller, Marianne R; Rosenbohm, Christoph; Ørum, Henrik; Straarup, Ellen M; Koch, Troels


    Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a therapeutic target for the reduction of low-density lipoprotein cholesterol (LDL-C). PCSK9 increases the degradation of the LDL receptor, resulting in high LDL-C in individuals with high PCSK9 activity. Here, we show that two locked nucleic acid (LNA) antisense oligonucleotides targeting PCSK9 produce sustained reduction of LDL-C in nonhuman primates after a loading dose (20 mg/kg) and four weekly maintenance doses (5 mg/kg). PCSK9 messenger RNA (mRNA) and serum PCSK9 protein were reduced by 85% which resulted in a 50% reduction in circulating LDL-C. Serum total cholesterol (TC) levels were reduced to the same extent as LDL-C with no reduction in high-density lipoprotein levels, demonstrating a specific pharmacological effect on LDL-C. The reduction in hepatic PCSK9 mRNA correlated with liver LNA oligonucleotide content. This verified that anti-PCSK9 LNA oligonucleotides regulated LDL-C through an antisense mechanism. The compounds were well tolerated with no observed effects on toxicological parameters (liver and kidney histology, alanine aminotransferase, aspartate aminotransferase, urea, and creatinine). The pharmacologic evidence and initial safety profile of the compounds used in this study indicate that LNA antisense oligonucleotides targeting PCSK9 provide a viable therapeutic strategy and are potential complements to statins in managing high LDL-C.

  16. Design and analysis of effects of triplet repeat oligonucleotides in cell models for myotonic dystrophy

    NARCIS (Netherlands)

    Gonzalez-Barriga, A.; Mulders, S.A.M.; Giessen, J. van der; Hooijer, J.D.; Bijl, S.; Kessel, I.D.G. van; Beers, J. van; Deutekom, J.C. van; Fransen, J.A.M.; Wieringa, B.; Wansink, D.G.


    Myotonic dystrophy type 1 (DM1) is caused by DM protein kinase (DMPK) transcripts containing an expanded (CUG)n repeat. Antisense oligonucleotide (AON)-mediated suppression of these mutant RNAs is considered a promising therapeutic strategy for this severe disorder. Earlier, we identified a 2'-O-met

  17. Negative electrospray ionization mass spectrometry of synthetic and chemically modified oligonucleotides

    NARCIS (Netherlands)

    Potier, N.; Van Dorsselaer, A.; Cordier, Y.; Roch, O.; Bischoff, Rainer


    We report here on the analysis of synthetic oligonucleotides by electrospray ionization mass spectrometry (ESI-MS). After intensive removal of salt ions (especially sodium cations), negative ion mass spectra, allowing mass measurement with an accuracy of 0.01%, were obtained on several oligonucleoti

  18. Methods for the preparation of large quantities of complex single-stranded oligonucleotide libraries.

    Directory of Open Access Journals (Sweden)

    Yusuf E Murgha

    Full Text Available Custom-defined oligonucleotide collections have a broad range of applications in fields of synthetic biology, targeted sequencing, and cytogenetics. Also, they are used to encode information for technologies like RNA interference, protein engineering and DNA-encoded libraries. High-throughput parallel DNA synthesis technologies developed for the manufacture of DNA microarrays can produce libraries of large numbers of different oligonucleotides, but in very limited amounts. Here, we compare three approaches to prepare large quantities of single-stranded oligonucleotide libraries derived from microarray synthesized collections. The first approach, alkaline melting of double-stranded PCR amplified libraries with a biotinylated strand captured on streptavidin coated magnetic beads results in little or no non-biotinylated ssDNA. The second method wherein the phosphorylated strand of PCR amplified libraries is nucleolyticaly hydrolyzed is recommended when small amounts of libraries are needed. The third method combining in vitro transcription of PCR amplified libraries to reverse transcription of the RNA product into single-stranded cDNA is our recommended method to produce large amounts of oligonucleotide libraries. Finally, we propose a method to remove any primer binding sequences introduced during library amplification.

  19. Obstructive Effects of Ultrasonic Microbubble Intensifier on CHG-5 Cell with Survivin Antisense Oligonucleotides Transfection

    Institute of Scientific and Technical Information of China (English)

    CAO Hong-ying; CAO You-de; WANG Zhi-gang; LI Pan


    Objective:To study the effects on human glioma cell line CHG-5 by ultrasonic microbubble intensifier with survivin antisense oligonucleotides (ASODN)transfection. Methods: Antisense oligonucleotides targeting survivin mRNA was designed and synthesized.Four regimen groups were designed,group A:survivin antisense oligonucleotides transfected with ultrasonic microbubble intensifier combined with ultrasound irradiation,group B: survivin antisense oligonucleotides transfected with lipofectamine combined with ultrasound irradiation,group C:survivin antisense oligonucelotides with lipofectamine D:blank control.The expression changes of surviving protein were measured by immunohistochemical staining and Western blotting,and MTr assay was used to measure the changes of proliferation.Results:Survivin protein expression in group A was decreased significantly in human glioma cell line CHG-5 than other groups(P<0.05),and the proliferating rate of CHG-5 in group A was also significantly inhibited(P<0.05).Conclusion:Ultrasonic microbubble intensifier transfection combined with ultrasound irradiation is a promising method in gene transfection effectively and noninvasively.

  20. An oligonucleotide-tagged microarray for routine diagnostics of colon cancer by genotyping KRAS mutations

    DEFF Research Database (Denmark)

    Liu, Yuliang; Guðnason, Haukur; Li, Yiping


    or spiked fecal samples. The immobilized tag-probes were stable under multiple thermal cycling treatments, allowing re-use of the tag-microarray and further optimization to solid PCR. Our results demonstrated that a novel oligonucleotide-tagged microarray system has been developed which would be suitable...

  1. Oligonucleotide array outperforms SNP array on formalin-fixed paraffin-embedded clinical samples. (United States)

    Nasri, Soroush; Anjomshoaa, Ahmad; Song, Sarah; Guilford, Parry; McNoe, Les; Black, Michael; Phillips, Vicky; Reeve, Anthony; Humar, Bostjan


    Compromised quality of formalin-fixed paraffin-embedded (FFPE)-derived DNA has compounded the use of archival specimens for array-based genomic studies. Recent technological advances have led to first successes in this field; however, there is currently no general agreement on the most suitable platform for the array-based analysis of FFPE DNA. In this study, FFPE and matched fresh-frozen (FF) specimens were separately analyzed with Affymetrix single nucleotide polymorphism (SNP) 6.0 and Agilent 4x44K oligonucleotide arrays to compare the genomic profiles from the two tissue sources and to assess the relative performance of the two platforms on FFPE material. Genomic DNA was extracted from matched FFPE-FF pairs of normal intestinal epithelium from four patients and were applied to the SNP and oligonucleotide platforms according to the manufacturer-recommended protocols. On the Affymetrix platform, a substantial increase in apparent copy number alterations was observed in all FFPE tissues relative to their matched FF counterparts. In contrast, FFPE and matched FF genomic profiles obtained via the Agilent platform were very similar. Both the SNP and the oligonucleotide platform performed comparably on FF material. This study demonstrates that Agilent oligonucleotide array comparative genomic hybridization generates reliable results from FFPE extracted DNA, whereas the Affymetrix SNP-based array seems less suitable for the analysis of FFPE material.

  2. Tetrahedron-structured DNA and functional oligonucleotide for construction of an electrochemical DNA-based biosensor. (United States)

    Bu, Nan-Nan; Tang, Chun-Xia; He, Xi-Wen; Yin, Xue-Bo


    Tetrahedron-structured DNA (ts-DNA) in combination with a functionalized oligonucleotide was used to develop a "turn-on" biosensor for Hg(2+) ions. The ts-DNA provided an improved sensitivity and was used to block the active sites.

  3. An oral oligonucleotide delivery system based on a thiolated polymer: Development and in vitro evaluation. (United States)

    Martien, Ronny; Hoyer, Herbert; Perera, Glen; Schnürch, Andreas Bernkop


    The purpose of this study was to develop and evaluate an oral oligonucleotide delivery system based on a thiolated polymer/reduced glutathione (GSH) system providing a protective effect toward nucleases and permeation enhancement. A polycarbophil-cysteine conjugate (PCP-Cys) was synthesized. Enzymatic degradation of a model oligonucleotide by DNase I and within freshly collected intestinal fluid was investigated in the absence and presence of PCP-Cys. Permeation studies with PCP-Cys/GSH versus control were performed in vitro on Caco-2 cell monolayers and ex vivo on rat intestinal mucosa. PCP-Cys displayed 223 ± 13.8 μmol thiol groups per gram polymer. After 4h, 61% of the free oligonucleotides were degraded by DNase I and 80% within intestinal fluid. In contrast, less than 41% (DNase I) and 60% (intestinal fluid) were degraded in the presence of 0.02% (m/v) PCP-Cys. Permeation studies revealed an 8-fold (Caco-2) and 10-fold (intestinal mucosa) increase in apparent permeability compared to buffer control. Hence, this PCP-Cys/GSH system might be a promising tool for the oral administration of oligonucleotides as it allows a significant protection toward degrading enzymes and facilitates their transport across intestinal membranes.

  4. The shape of terrestrial abundance distributions. (United States)

    Alroy, John


    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood-related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the "double geometric." Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly.

  5. Angel lichen moth abundance and morphology data (United States)

    Metcalfe, Anya; Kennedy, Theodore A.; Muehlbauer, Jeffrey D.


    Two unique datasets on the abundance and morphology of the angel lichen moth ( Cisthene angelus) in Grand Canyon, Arizona, USA were compiled to describe the phenology and life history of this common, but poorly known, species. The abundance data were collected from 2012 to 2013 through a collaboration with river runners in Grand Canyon National Park. These citizen scientists deployed light traps from their campsites for one hour each night of their expedition. Insects were preserved in ethanol on site, and returned to the Southwest Biological Science Center in Flagstaff, Arizona for analysis in the laboratory. A total of 2,437 light trap samples were sorted through, 903 of which contained C. angelus. In total, 73,841 C. angelus were identified and enumerated to create the abundance data set. The morphology dataset is based on a subset of 28 light trap samples from sampling year 2012 (14 from spring and 14 from fall.) It includes gender and forewing lengths for 2,674 individual moths and dry weights for 1,102 of those individuals.

  6. Short G-rich oligonucleotides as a potential therapeutic for Huntington's Disease

    Directory of Open Access Journals (Sweden)

    Parekh-Olmedo Hetal


    Full Text Available Abstract Background Huntington's Disease (HD is an inherited autosomal dominant genetic disorder in which neuronal tissue degenerates. The pathogenesis of the disease appears to center on the development of protein aggregates that arise initially from the misfolding of the mutant HD protein. Mutant huntingtin (Htt is produced by HD genes that contain an increased number of glutamine codons within the first exon and this expansion leads to the production of a protein that misfolds. Recent studies suggest that mutant Htt can nucleate protein aggregation and interfere with a multitude of normal cellular functions. Results As such, efforts to find a therapy for HD have focused on agents that disrupt or block the mutant Htt aggregation pathway. Here, we report that short guanosine monotonic oligonucleotides capable of adopting a G-quartet structure, are effective inhibitors of aggregation. By utilizing a biochemical/immunoblotting assay as an initial screen, we identified a 20-mer, all G-oligonucleotide (HDG as an active molecule. Subsequent testing in a cell-based assay revealed that HDG was an effective inhibitor of aggregation of a fusion protein, comprised of a mutant Htt fragment and green fluorescent protein (eGFP. Taken together, our results suggest that a monotonic G-oligonucleotide, capable of adopting a G-quartet conformation is an effective inhibitor of aggregation. This oligonucleotide can also enable cell survival in PC12 cells overexpressing a mutant Htt fragment fusion gene. Conclusion Single-stranded DNA oligonucleotides capable of forming stable G-quartets can inhibit aggregation of the mutant Htt fragment protein. This activity maybe an important part of the pathogenecity of Huntington's Disease. Our results reveal a new class of agents that could be developed as a therapeutic approach for Huntington's Disease.

  7. Modulation of 5' splice site selection using tailed oligonucleotides carrying splicing signals

    Directory of Open Access Journals (Sweden)

    Elela Sherif


    Full Text Available Abstract Background We previously described the use of tailed oligonucleotides as a means of reprogramming alternative pre-mRNA splicing in vitro and in vivo. The tailed oligonucleotides that were used interfere with splicing because they contain a portion complementary to sequences immediately upstream of the target 5' splice site combined with a non-hybridizing 5' tail carrying binding sites for the hnRNP A1/A2 proteins. In the present study, we have tested the inhibitory activity of RNA oligonucleotides carrying different tail structures. Results We show that an oligonucleotide with a 5' tail containing the human β-globin branch site sequence inhibits the use of the 5' splice site of Bcl-xL, albeit less efficiently than a tail containing binding sites for the hnRNP A1/A2 proteins. A branch site-containing tail positioned at the 3' end of the oligonucleotide also elicited splicing inhibition but not as efficiently as a 5' tail. The interfering activity of a 3' tail was improved by adding a 5' splice site sequence next to the branch site sequence. A 3' tail carrying a Y-shaped branch structure promoted similar splicing interference. The inclusion of branch site or 5' splice site sequences in the Y-shaped 3' tail further improved splicing inhibition. Conclusion Our in vitro results indicate that a variety of tail architectures can be used to elicit splicing interference at low nanomolar concentrations, thereby broadening the scope and the potential impact of this antisense technology.

  8. Phage annealing proteins promote oligonucleotide-directed mutagenesis in Escherichia coli and mouse ES cells

    Directory of Open Access Journals (Sweden)

    Muyrers Joep PP


    Full Text Available Abstract Background The phage protein pairs, RecE/RecT from Rac or Redα/Redβ from λ, initiate efficient double strand break repair (DSBR in Escherichia coli that has proven very useful for DNA engineering. These phage pairs initiate DSBR either by annealing or by another mechanism that is not defined. Results Here we report that these proteins also mediate single strand oligonucleotide repair (ssOR at high efficiencies. The ssOR activity, unlike DSBR, does not require a phage exonuclease (RecE or Redα but only requires a phage annealing protein (RecT or Redβ. Notably, the P22 phage annealing protein Erf, which does not mediate the same DSBR reactions, also delivers ssOR activity. By altering aspects of the oligonucleotides, we document length and design parameters that affect ssOR efficiency to show a simple relationship to homologies either side of the repair site. Notably, ssOR shows strand bias. Oligonucleotides that can prime lagging strand replication deliver more ssOR than their leading complements. This suggests a model in which the annealing proteins hybridize the oligonucleotides to single stranded regions near the replication fork. We also show that ssOR is a highly efficient way to engineer BACs and can be detected in a eukaryotic cell upon expression of a phage annealing protein. Conclusion Phage annealing proteins can initiate the recombination of single stranded oligonucleotides into endogenous targets in Escherichia coli at very high efficiencies. This expands the repertoire of useful DNA engineering strategies, shows promise for applications in eukaryotic cells, and has implications for the unanswered questions regarding DSBR mediated by RecE/RecT and Redα/Redβ.

  9. Development, characterization and experimental validation of a cultivated sunflower (Helianthus annuus L. gene expression oligonucleotide microarray.

    Directory of Open Access Journals (Sweden)

    Paula Fernandez

    Full Text Available Oligonucleotide-based microarrays with accurate gene coverage represent a key strategy for transcriptional studies in orphan species such as sunflower, H. annuus L., which lacks full genome sequences. The goal of this study was the development and functional annotation of a comprehensive sunflower unigene collection and the design and validation of a custom sunflower oligonucleotide-based microarray. A large scale EST (>130,000 ESTs curation, assembly and sequence annotation was performed using Blast2GO ( The EST assembly comprises 41,013 putative transcripts (12,924 contigs and 28,089 singletons. The resulting Sunflower Unigen Resource (SUR version 1.0 was used to design an oligonucleotide-based Agilent microarray for cultivated sunflower. This microarray includes a total of 42,326 features: 1,417 Agilent controls, 74 control probes for sunflower replicated 10 times (740 controls and 40,169 different non-control probes. Microarray performance was validated using a model experiment examining the induction of senescence by water deficit. Pre-processing and differential expression analysis of Agilent microarrays was performed using the Bioconductor limma package. The analyses based on p-values calculated by eBayes (p<0.01 allowed the detection of 558 differentially expressed genes between water stress and control conditions; from these, ten genes were further validated by qPCR. Over-represented ontologies were identified using FatiScan in the Babelomics suite. This work generated a curated and trustable sunflower unigene collection, and a custom, validated sunflower oligonucleotide-based microarray using Agilent technology. Both the curated unigene collection and the validated oligonucleotide microarray provide key resources for sunflower genome analysis, transcriptional studies, and molecular breeding for crop improvement.

  10. Development, characterization and experimental validation of a cultivated sunflower (Helianthus annuus L.) gene expression oligonucleotide microarray. (United States)

    Fernandez, Paula; Soria, Marcelo; Blesa, David; DiRienzo, Julio; Moschen, Sebastian; Rivarola, Maximo; Clavijo, Bernardo Jose; Gonzalez, Sergio; Peluffo, Lucila; Príncipi, Dario; Dosio, Guillermo; Aguirrezabal, Luis; García-García, Francisco; Conesa, Ana; Hopp, Esteban; Dopazo, Joaquín; Heinz, Ruth Amelia; Paniego, Norma


    Oligonucleotide-based microarrays with accurate gene coverage represent a key strategy for transcriptional studies in orphan species such as sunflower, H. annuus L., which lacks full genome sequences. The goal of this study was the development and functional annotation of a comprehensive sunflower unigene collection and the design and validation of a custom sunflower oligonucleotide-based microarray. A large scale EST (>130,000 ESTs) curation, assembly and sequence annotation was performed using Blast2GO ( The EST assembly comprises 41,013 putative transcripts (12,924 contigs and 28,089 singletons). The resulting Sunflower Unigen Resource (SUR version 1.0) was used to design an oligonucleotide-based Agilent microarray for cultivated sunflower. This microarray includes a total of 42,326 features: 1,417 Agilent controls, 74 control probes for sunflower replicated 10 times (740 controls) and 40,169 different non-control probes. Microarray performance was validated using a model experiment examining the induction of senescence by water deficit. Pre-processing and differential expression analysis of Agilent microarrays was performed using the Bioconductor limma package. The analyses based on p-values calculated by eBayes (p<0.01) allowed the detection of 558 differentially expressed genes between water stress and control conditions; from these, ten genes were further validated by qPCR. Over-represented ontologies were identified using FatiScan in the Babelomics suite. This work generated a curated and trustable sunflower unigene collection, and a custom, validated sunflower oligonucleotide-based microarray using Agilent technology. Both the curated unigene collection and the validated oligonucleotide microarray provide key resources for sunflower genome analysis, transcriptional studies, and molecular breeding for crop improvement.

  11. Binding of Dumbbell Oligonucleotides to MoMuLV Reverse Transcriptase: Inhibitory Properties of RNase H Activity

    Directory of Open Access Journals (Sweden)

    Ajay Kumar


    Full Text Available Dumbbell oligonucleotides with loops of various chemistry were synthesized. Incubation of dumbbell oligonucleotides containing phosphorothioate bonds or trimethylene phosphate linkages in loops with S1 nuclease did not result in significant cleavage under conditions which led to the degradation of dumbbell oligonucleotide containing phophodiester bonds in the loops. The binding of reverse transcriptase of Moloney Murine Leukemia Virus (MoMuLV was evaluated with all the five oligonucleotides. The protein binds to all the dumbbell oligonucleotides with similar affinity. The dissociation constants evaluated using PAGE band mobility shift assays were of the order of 10-7. The inhibitory properties of the retroviral RNase H activity was evaluated using 3H –UTP-labeled RNA:RNA-DNA hybrid. It was found that the best dumbbell oligonucleotide, inhibitor contained phosphorothioate residues in both the loops. Our value studies demonstrated that this particularly designed oligonucleotide displays an IC50 of 18 nM in its inhibition on the reverse transcriptase RNase H activity, a magnitude lower than that of first nucleotide reverse transcriptase of HIV-1, tenofovir, introduced by Gilead Science in the market.

  12. Effect of CD44 Suppression by Antisense Oligonucleotide on Attachment of Human Trabecular Meshwork Cells to HA

    Institute of Scientific and Technical Information of China (English)

    李中国; 张虹


    The effects of suppression of CD44 by CD44-specific antisense oligonucleotide on attachment of human trabecular meshwork cells to hyaluronic acid (HA) were observed and the possible relationship between CD44 and primary open-angle glaucoma (POAG) investigated. CD44-specific antisense oligonucleotide was delivered with cationic lipid to cultured human trabecular meshwork cells. The expression of CD44 suppressed by CD44-specific antisense oligonucleotide was detected by RT-PCR and Western blotting. The effect of CD44 suppression by specific antisense oligonucleotide on attachment of trabecular meshwork cells to HA was measured by MTT assay. Results showed that expression of CD44 was suppressed by CD4, specific antisense oligonucleotide. Antisense oligonucleotide also suppressed the adhesion of human trabecular meshwork cells to HA in a concentration dependent manner. It was concluded that attachment of human trabecular meshwork cells to HA was decreased when CD44 was suppressed by specific antisense oligonucleotide. CD44might play a role in pathogenesis of POAG by affecting the adhesion of trabecular meshwork cells to HA.

  13. Triple helix-forming oligonucleotides conjugated to indolocarbazole poisons direct topoisomerase I-mediated DNA cleavage to a specific site. (United States)

    Arimondo, P B; Bailly, C; Boutorine, A S; Moreau, P; Prudhomme, M; Sun, J S; Garestier, T; Hélène, C


    Topoisomerase I is an ubiquitous DNA-cleaving enzyme and an important therapeutic target in cancer chemotherapy for camptothecins as well as for indolocarbazole antibiotics such as rebeccamycin. To achieve a sequence-specific cleavage of DNA by topoisomerase I, a triple helix-forming oligonucleotide was covalently linked to indolocarbazole-type topoisomerase I poisons. The three indolocarbazole-oligonucleotide conjugates investigated were able to direct topoisomerase I cleavage at a specific site based upon sequence recognition by triplex formation. The efficacy of topoisomerase I-mediated DNA cleavage depends markedly on the intrinsic potency of the drug. We show that DNA cleavage depends also upon the length of the linker arm between the triplex-forming oligonucleotide and the drug. Based on a known structure of the DNA-topoisomerase I complex, a molecular model of the oligonucleotide conjugates bound to the DNA-topoisomerase I complex was elaborated to facilitate the design of a potent topoisomerase I inhibitor-oligonucleotide conjugate with an optimized linker between the two moieties. The resulting oligonucleotide-indolocarbazole conjugate at 10 nM induced cleavage at the triple helix site 2-fold more efficiently than 5 microM of free indolocarbazole, while the other drug-sensitive sites were not cleaved. The rational design of drug-oligonucleotide conjugates carrying a DNA topoisomerase poison may be exploited to improve the efficacy and selectivity of chemotherapeutic cancer treatments by targeting specific genes and reducing drug toxicity.

  14. Comparative linkage analysis and visualization of high-density oligonucleotide SNP array data

    Directory of Open Access Journals (Sweden)

    Smith Richard JH


    Full Text Available Abstract Background The identification of disease-associated genes using single nucleotide polymorphisms (SNPs has been increasingly reported. In particular, the Affymetrix Mapping 10 K SNP microarray platform uses one PCR primer to amplify the DNA samples and determine the genotype of more than 10,000 SNPs in the human genome. This provides the opportunity for large scale, rapid and cost-effective genotyping assays for linkage analysis. However, the analysis of such datasets is nontrivial because of the large number of markers, and visualizing the linkage scores in the context of genome maps remains less automated using the current linkage analysis software packages. For example, the haplotyping results are commonly represented in the text format. Results Here we report the development of a novel software tool called CompareLinkage for automated formatting of the Affymetrix Mapping 10 K genotype data into the "Linkage" format and the subsequent analysis with multi-point linkage software programs such as Merlin and Allegro. The new software has the ability to visualize the results for all these programs in dChip in the context of genome annotations and cytoband information. In addition we implemented a variant of the Lander-Green algorithm in the dChipLinkage module of dChip software (V1.3 to perform parametric linkage analysis and haplotyping of SNP array data. These functions are integrated with the existing modules of dChip to visualize SNP genotype data together with LOD score curves. We have analyzed three families with recessive and dominant diseases using the new software programs and the comparison results are presented and discussed. Conclusions The CompareLinkage and dChipLinkage software packages are freely available. They provide the visualization tools for high-density oligonucleotide SNP array data, as well as the automated functions for formatting SNP array data for the linkage analysis programs Merlin and Allegro and calling

  15. Sequence diversity within the HA-1 gene as detected by melting temperature assay without oligonucleotide probes

    Directory of Open Access Journals (Sweden)

    Mattiuz Pier


    Full Text Available Abstract Background The minor histocompatibility antigens (mHags are self-peptides derived from common cellular proteins and presented by MHC class I and II molecules. Disparities in mHags are a potential risk for the development of graft-versus-host disease (GvHD in the recipients of bone marrow from HLA-identical donors. Two alleles have been identified in the mHag HA-1. The correlation between mismatches of the mHag HA-1 and GvHD has been suggested and methods to facilitate large-scale testing were afterwards developed. Methods We used sequence specific primer (SSP PCR and direct sequencing to detect HA-1 gene polymorphisms in a sample of 131 unrelated Italian subjects. We then set up a novel melting temperature (Tm assay that may help identification of HA-1 alleles without oligonucleotide probes. Results We report the frequencies of HA-1 alleles in the Italian population and the presence of an intronic 5 base-pair deletion associated with the immunogeneic allele HA-1H. We also detected novel variable sites with respect to the consensus sequence of HA-1 locus. Even though recombination/gene conversion events are documented, there is considerable linkage disequilibrium in the data. The gametic associations between HA-1R/H alleles and the intronic 5-bp ins/del polymorphism prompted us to try the Tm analysis with SYBR® Green I. We show that the addition of dimethylsulfoxide (DMSO during the assay yields distinct patterns when amplicons from HA-1H homozygotes, HA-1R homozygotes, and heterozygotes are analysed. Conclusion The possibility to use SYBR® Green I to detect Tm differences between allelic variants is attractive but requires great caution. We succeeded in allele discrimination of the HA-1 locus using a relatively short (101 bp amplicon, only in the presence of DMSO. We believe that, at least in certain assets, Tm assays may benefit by the addition of DMSO or other agents affecting DNA strand conformation and stability.

  16. OligoPrep PVA support for oligonucleotide synthesis in columns on a scale up to 10 micromol. (United States)

    Aitken, Sheena; Anderson, Emma


    OligoPrep is a macroporous polyvinylacetate (PVA) biodegradable support that has been designed for cost-effective automated synthesis of oligonucleotides using standard phosphoramidite chemistry. Originally developed for large-scale oligonucleotide synthesis in beds and reactors, we present here its utility for medium-scale work of 1-10 micromol in column syntheses on standard DNA synthesizers. We show how an increase in scale, and, therefore, yield, can be achieved without significant increase in reagent quantity. Additional deblock and oxidation cycles can provide high coupling yields, and the use of concentrated ammonia in aqueous methylamine (AMA) for oligonucleotide cleavage and deprotection results in excellent recovery.

  17. Amino acids attached to 2'-amino-LNA: Synthesis of DNA mixmer oligonucleotides with increased duplex stability

    DEFF Research Database (Denmark)

    Johannsen, Marie Willaing; Wengel, Jesper; Wamberg, Michael Chr.;


    The synthesis of 2'-amino-LNA (locked nucleic acid) opens up exciting possibilities for modification of nucleic acids by conjugation to the 2'-nitrogen. Incorporation of unmodified and N-functionalized 2'-amino-LNA nucleotides improve duplex stability compared to unmodified DNA. 2'-Amino......-LNA nucleosides derivatized with amino acids have been synthesized and incorporated into DNA oligonucleotides. Following oligonucleotide synthesis, peptides have been added using solid phase peptide coupling chem. Modification of oligonucleotides with pos. charged residues greatly improves thermal stability....

  18. Optimization and scale-up of oligonucleotide synthesis in packed bed reactors using computational fluid dynamics modeling. (United States)

    Wolfrum, Christian; Josten, Andre; Götz, Peter


    A computational fluid dynamics (CFD) model for the analysis of oligonucleotide synthesis in packed bed reactors was developed and used to optimize the scale up of the process. The model includes reaction kinetics data obtained under well defined conditions comparable to the situation in the packed bed. The model was validated in terms of flow conditions and reaction kinetics by comparison with experimental data. Experimental validation and the following model parameter studies by simulation were performed on the basis of a column with 0.3 g oligonucleotide capacity. The scale-up studies based on CFD modelling were calculated on a 440 g scale (oligonucleotide capacity).

  19. Characterization of the nanostructure of complexes formed by single- or double-stranded oligonucleotides with a cationic surfactant. (United States)

    Liu, Xiaoyang; Abbott, Nicholas L


    We report the use of dynamic light scattering (DLS), small-angle neutron scattering (SANS), and small-angle X-ray scattering (SAXS) to characterize the nanostructure of complexes formed by either single- or double-stranded oligonucleotides with a cationic surfactant (cetyltrimethylammonium bromide, CTAB) in aqueous solution (1 mM Li(2)SO(4)). For single-stranded oligonucleotides 5'-A(20)-3' and 5'-CCCCATTCTAGCAGCCCGGG-3', both the appearance of two Bragg peaks (at 0.14 and 0.28 Å(-1)) in SAXS spectra with a spacing of 1:2 and form factor fits to SANS spectra are consistent with the presence of multilamellar vesicles (with, on average, 6-9 layers with a periodicity of 45-48 Å). Some samples showed evidence of an additional Bragg peak (at 0.20 Å(-1)) associated with periodic packing (with a periodicity of 31 Å) of the oligonucleotides within the lamellae of the nanostructure. The nucleotide composition of the single-stranded oligonucleotides was also found to impact the number and size of the complexes formed with CTAB. In contrast to 5'-A(20)-3' and 5'-CCCCATTCTAGCAGCCCGGG-3', 5'-T(20)-3' did not change the state of aggregation of CTAB (globular micelles) over a wide range of oligonucleotide:CTAB charge ratios. These results support the proposition that hydrophobic interactions, as well as electrostatics, play a central role in the formation of complexes between cationic amphiphiles and single-stranded oligonucleotides and thus give rise to nanostructures that depend on nucleotide composition. In contrast to the single-stranded oligonucleotides, for double-stranded oligonucleotides mixed with CTAB, three Bragg peaks (0.13, 0.23, and 0.25 Å(-1)) in SAXS spectra with a spacing ratio of 1:√3:√4 and characteristic changes in SANS spectra indicate formation of a hexagonal nanostructure. Also, the composition of the double-stranded oligonucleotides did not measurably impact the nanostructure of complexes formed with CTAB, suggesting that electrostatic

  20. Gd Transition Probabilities and Abundances

    CERN Document Server

    Den Hartog, E A; Sneden, C; Cowan, J J


    Radiative lifetimes, accurate to +/- 5%, have been measured for 49 even-parity and 14 odd-parity levels of Gd II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 611 lines of Gd II. This work is the largest-scale laboratory study to date of Gd II transition probabilities and the first using a high performance Fourier transform spectrometer. This improved data set has been used to determine a new solar photospheric Gd abundance, log epsilon = 1.11 +/- 0.03. Revised Gd abundances have also been derived for the r-process-rich metal-poor giant stars CS 22892-052, BD+17 3248, and HD 115444. The resulting Gd/Eu abundance ratios are in very good agreement with the solar-system r-process ratio. We have employed the increasingly accurate stellar abundance determinations, resulting in large part from the more precise laboratory atomic data, to predict directly the Solar System r-process elemental...

  1. Coho Abundance - Point Features [ds182 (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  2. Chinook Abundance - Point Features [ds180 (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  3. Coho Abundance - Linear Features [ds183 (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  4. Steelhead Abundance - Point Features [ds184 (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  5. Steelhead Abundance - Linear Features [ds185 (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  6. Abundance estimation and Conservation Biology

    Directory of Open Access Journals (Sweden)

    Nichols, J. D.


    Full Text Available Abundance is the state variable of interest in most population–level ecological research and in most programs involving management and conservation of animal populations. Abundance is the single parameter of interest in capture–recapture models for closed populations (e.g., Darroch, 1958; Otis et al., 1978; Chao, 2001. The initial capture–recapture models developed for partially (Darroch, 1959 and completely (Jolly, 1965; Seber, 1965 open populations represented efforts to relax the restrictive assumption of population closure for the purpose of estimating abundance. Subsequent emphases in capture–recapture work were on survival rate estimation in the 1970’s and 1980’s (e.g., Burnham et al., 1987; Lebreton et al.,1992, and on movement estimation in the 1990’s (Brownie et al., 1993; Schwarz et al., 1993. However, from the mid–1990’s until the present time, capture–recapture investigators have expressed a renewed interest in abundance and related parameters (Pradel, 1996; Schwarz & Arnason, 1996; Schwarz, 2001. The focus of this session was abundance, and presentations covered topics ranging from estimation of abundance and rate of change in abundance, to inferences about the demographic processes underlying changes in abundance, to occupancy as a surrogate of abundance. The plenary paper by Link & Barker (2004 is provocative and very interesting, and it contains a number of important messages and suggestions. Link & Barker (2004 emphasize that the increasing complexity of capture–recapture models has resulted in large numbers of parameters and that a challenge to ecologists is to extract ecological signals from this complexity. They offer hierarchical models as a natural approach to inference in which traditional parameters are viewed as realizations of stochastic processes. These processes are governed by hyperparameters, and the inferential approach focuses on these hyperparameters. Link & Barker (2004 also suggest that

  7. Abundance estimation and conservation biology (United States)

    Nichols, J.D.; MacKenzie, D.I.


    Abundance is the state variable of interest in most population–level ecological research and in most programs involving management and conservation of animal populations. Abundance is the single parameter of interest in capture–recapture models for closed populations (e.g., Darroch, 1958; Otis et al., 1978; Chao, 2001). The initial capture–recapture models developed for partially (Darroch, 1959) and completely (Jolly, 1965; Seber, 1965) open populations represented efforts to relax the restrictive assumption of population closure for the purpose of estimating abundance. Subsequent emphases in capture–recapture work were on survival rate estimation in the 1970’s and 1980’s (e.g., Burnham et al., 1987; Lebreton et al.,1992), and on movement estimation in the 1990’s (Brownie et al., 1993; Schwarz et al., 1993). However, from the mid–1990’s until the present time, capture–recapture investigators have expressed a renewed interest in abundance and related parameters (Pradel, 1996; Schwarz & Arnason, 1996; Schwarz, 2001). The focus of this session was abundance, and presentations covered topics ranging from estimation of abundance and rate of change in abundance, to inferences about the demographic processes underlying changes in abundance, to occupancy as a surrogate of abundance. The plenary paper by Link & Barker (2004) is provocative and very interesting, and it contains a number of important messages and suggestions. Link & Barker (2004) emphasize that the increasing complexity of capture–recapture models has resulted in large numbers of parameters and that a challenge to ecologists is to extract ecological signals from this complexity. They offer hierarchical models as a natural approach to inference in which traditional parameters are viewed as realizations of stochastic processes. These processes are governed by hyperparameters, and the inferential approach focuses on these hyperparameters. Link & Barker (2004) also suggest that our attention

  8. Relative abundance of desert tortoises on the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Rautenstrauch, K.R.; O`Farrell, T.P.


    Seven hundred fifty-nine transects having a total length of 1,191 km were walked during 1981--1986 to determine the distribution and relative abundance of desert tortoises (Gopherus agassizii) on the Nevada Test Site (NTS). The abundance of tortoises on NTS was low to very low relative to other populations in the Mojave Desert. Sign of tortoises was found from 880 to 1,570 m elevation and was more abundant above 1,200 m than has been reported previously for Nevada. Tortoises were more abundant on NTS on the upper alluvial fans and slopes of mountains than in valley bottoms. They also were more common on or near limestone and dolomite mountains than on mountains of volcanic origin.

  9. Synthesis of the Tellurium-Derivatized Phosphoramidites and their Incorporation into DNA Oligonucleotides (United States)

    Jiang, Sibo; Sheng, Jia


    Introduction In this unit, an efficient method for the synthesis of 2’-tellerium modified phosphoramidite and its incorporation into oligonucleotide are presented. We choose 5’-O-DMTr-2,2’-anhydro-uridine and -thymidine nucleosides (S.1, S.2) as starting materials due to their easy preparation. The 5’-O-DMTr-2,2’-anhydro-uridine and -thymidine can be converted to corresponding the 2’-tellerium-derivatized nucleosides by treating with the telluride nucleophiles. Subsequently, the 2’-Te-nucleosides can be transformed into 3’-phosphoramidites, which are the building blocks for DNA/RNA synthesis. The DNA synthesis, purification and applications of oligonucleotides containing 2’-Te-U or 2’-Te-T are described in this protocol. PMID:22147418

  10. Ultramild protein-mediated click chemistry creates efficient oligonucleotide probes for targeting and detecting nucleic acids

    DEFF Research Database (Denmark)

    Nåbo, Lina J.; Madsen, Charlotte Stahl; Jensen, Knud Jørgen


    results by electronic structure calculations. Functionalized oligonucleotides were prepared in good yields by protein-mediated CuAAC click reactions for the first time with a human copper-binding chaperon. The carbohydrate, peptide, and fluorescent derivatives display high binding affinity and selectivity...... targeting and detection properties. We focus in particular on the pH sensitivity of these new probes and their high target specificity. For the first time, human copper(I)-binding chaperon Cox17 was applied to effectively catalyze click labeling of oligonucleotides. This was performed under ultramild...... conditions with fluorophore, peptide, and carbohydrate azide derivatives. In thermal denaturation studies, the modified probes showed specific binding to complementary DNA and RNA targets. Finally, we demonstrated the pH sensitivity of the new rhodamine-based fluorescent probes in vitro and rationalize our...

  11. Clinical potential of oligonucleotide-based therapeutics in the respiratory system. (United States)

    Moschos, Sterghios A; Usher, Louise; Lindsay, Mark A


    The discovery of an ever-expanding plethora of coding and non-coding RNAs with nodal and causal roles in the regulation of lung physiology and disease is reinvigorating interest in the clinical utility of the oligonucleotide therapeutic class. This is strongly supported through recent advances in nucleic acids chemistry, synthetic oligonucleotide delivery and viral gene therapy that have succeeded in bringing to market at least three nucleic acid-based drugs. As a consequence, multiple new candidates such as RNA interference modulators, antisense, and splice switching compounds are now progressing through clinical evaluation. Here, manipulation of RNA for the treatment of lung disease is explored, with emphasis on robust pharmacological evidence aligned to the five pillars of drug development: exposure to the appropriate tissue, binding to the desired molecular target, evidence of the expected mode of action, activity in the relevant patient population and commercially viable value proposition.

  12. The Role of Fluorinated Alcohols as Mobile Phase Modifiers for LC-MS Analysis of Oligonucleotides (United States)

    Basiri, Babak; van Hattum, Hilde; van Dongen, William D.; Murph, Mandi M.; Bartlett, Michael G.


    Hexafluoroisopropanol (HFIP) has been widely used as an acidic modifier for mobile phases for liquid chromatography-mass spectrometry (LC-MS) analysis of oligonucleotides ever since the first report of its use for this purpose. This is not surprising, considering the exceptional performance of HFIP compared with carboxylic acids, which cause significant MS signal suppression in electrospray ionization. However, we have found that other fluorinated alcohols can also be utilized for mobile phase preparation and the choice of optimal fluorinated alcohol is determined by the ion-pairing (IP) agent. Although HFIP is a very good choice to be used alongside less hydrophobic IP agents, other fluorinated alcohols such as 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol (HFMIP) can significantly outperform HFIP when used with more hydrophobic IP agents. We also found that more acidic fluorinated alcohols assist with the transfer of oligonucleotides with secondary structure (e.g., folded strands and hairpins) into the gas phase.

  13. Ultrahigh molecular recognition specificity of competing DNA oligonucleotide strands in thermal equilibrium

    CERN Document Server

    Schenkelberger, Marc; Mai, Timo; Ott, Albrecht


    The specificity of molecular recognition is important to molecular self-organization. A prominent example is the biological cell where, within a highly crowded molecular environment, a myriad of different molecular receptor pairs recognize their binding partner with astonishing accuracy. In thermal equilibrium it is usually admitted that the affinity of recognizer pairs only depends on the nature of the two binding molecules. Accordingly, Boltzmann factors of binding energy differences relate the molecular affinities among different target molecules that compete for the same probe. Here, we consider the molecular recognition of short DNA oligonucleotide single strands. We show that a better matching oligonucleotide strand can prevail against a disproportionally more concentrated competitor that exhibits reduced affinity due to a mismatch. The magnitude of deviation from the simple picture above may reach several orders of magnitude. In our experiments the effective molecular affinity of a given strand remains...

  14. Computer selection of oligonucleotide probes from amino acid sequences for use in gene library screening. (United States)

    Yang, J H; Ye, J H; Wallace, D C


    We present a computer program, FINPROBE, which utilizes known amino acid sequence data to deduce minimum redundancy oligonucleotide probes for use in screening cDNA or genomic libraries or in primer extension. The user enters the amino acid sequence of interest, the desired probe length, the number of probes sought, and the constraints on oligonucleotide synthesis. The computer generates a table of possible probes listed in increasing order of redundancy and provides the location of each probe in the protein and mRNA coding sequence. Activation of a next function provides the amino acid and mRNA sequences of each probe of interest as well as the complementary sequence and the minimum dissociation temperature of the probe. A final routine prints out the amino acid sequence of the protein in parallel with the mRNA sequence listing all possible codons for each amino acid.

  15. Photoswitchable oligonucleotide-modified gold nanoparticles: controlling hybridization stringency with photon dose. (United States)

    Yan, Yunqi; Chen, Jennifer I L; Ginger, David S


    We describe a new class of stimulus-responsive DNA-functionalized gold nanoparticles that incorporate azobenzene-modified oligonucleotides. Beyond the classic directed assembly and sensing behaviors associated with oligonucleotide-modified nanoparticles, these particles also exhibit reversible photoswitching of their assembly behavior. Exposure to UV light induces a trans-cis isomerization of the azobenzene which destabilizes the DNA duplex, resulting in dissociation of the nanoparticle assemblies. The isomerization is reversible upon exposure to blue light, resulting in rehybridization and reassembly of the DNA-linked nanoparticle clusters. We show that perfectly complementary and partially mismatched strands exhibit clearly distinguishable photoinduced melting properties, and we demonstrate that photon dose can thus be used in place of temperature or ionic strength to control hybridization stringency with the ability to discriminate single-base mismatches.

  16. Antibacterial Activity of DNA-Stabilized Silver Nanoclusters Tuned by Oligonucleotide Sequence. (United States)

    Javani, Siamak; Lorca, Romina; Latorre, Alfonso; Flors, Cristina; Cortajarena, Aitziber L; Somoza, Álvaro


    Silver nanoclusters (AgNCs) stabilized by DNA are promising materials with tunable fluorescent properties, which have been employed in a plethora of sensing systems. In this report, we explore their antimicrobial properties in Gram-positive and Gram-negative bacteria. After testing 9 oligonucleotides with different sequence and length, we found that the antibacterial activity depends on the sequence of the oligonucleotide employed. The sequences tested yielded fluorescent AgNCs, which can be grouped in blue, yellow, and red emitters. Interestingly, blue emitters yielded poor antibacterial activity, whereas yellow and red emitters afforded an activity similar to silver nitrate. Furthermore, structural studies using circular dichroism indicate the formation of complexes with different stability and structure, which might be one of the factors that modulate their activity. Finally, we prepared a trimeric structure containing the sequence that afforded the best antimicrobial activity, which inhibited the growth of Gram-positive and negative bacteria in the submicromolar range.

  17. Efficient Synthesis and Biological Evaluation of 5'-GalNAc Conjugated Antisense Oligonucleotides. (United States)

    Østergaard, Michael E; Yu, Jinghua; Kinberger, Garth A; Wan, W Brad; Migawa, Michael T; Vasquez, Guillermo; Schmidt, Karsten; Gaus, Hans J; Murray, Heather M; Low, Audrey; Swayze, Eric E; Prakash, Thazha P; Seth, Punit P


    Conjugation of triantennary N-acetyl galactosamine (GalNAc) to oligonucleotide therapeutics results in marked improvement in potency for reducing gene targets expressed in hepatocytes. In this report we describe a robust and efficient solution-phase conjugation strategy to attach triantennary GalNAc clusters (mol. wt. ∼2000) activated as PFP (pentafluorophenyl) esters onto 5'-hexylamino modified antisense oligonucleotides (5'-HA ASOs, mol. wt. ∼8000 Da). The conjugation reaction is efficient and was used to prepare GalNAc conjugated ASOs from milligram to multigram scale. The solution phase method avoids loading of GalNAc clusters onto solid-support for automated synthesis and will facilitate evaluation of GalNAc clusters for structure activity relationship (SAR) studies. Furthermore, we show that transfer of the GalNAc cluster from the 3'-end of an ASO to the 5'-end results in improved potency in cells and animals.

  18. Recognition and sensing of low-epitope targets via ternary complexes with oligonucleotides and synthetic receptors (United States)

    Yang, Kyung-Ae; Barbu, Mihaela; Halim, Marlin; Pallavi, Payal; Kim, Benjamin; Kolpashchikov, Dmitry M.; Pecic, Stevan; Taylor, Steven; Worgall, Tilla S.; Stojanovic, Milan N.


    Oligonucleotide-based receptors or aptamers can interact with small molecules, but the ability to achieve high-affinity and specificity of these interactions depends strongly on functional groups or epitopes displayed by the binding targets. Some classes of targets are particularly challenging: for example, monosaccharides have scarce functionalities and no aptamers have been reported to recognize, let alone distinguish from each other, glucose and other hexoses. Here we report aptamers that differentiate low-epitope targets such as glucose, fructose or galactose by forming ternary complexes with high-epitope organic receptors for monosaccharides. In a follow-up example, we expand this method to isolate high-affinity oligonucleotides against aromatic amino acids complexed in situ with a nonspecific organometallic receptor. The method is general and enables broad clinical use of aptamers for the detection of small molecules in mix-and-measure assays, as demonstrated by monitoring postprandial waves of phenylalanine in human subjects.

  19. Crystallization of a member of the recFOR DNA repair pathway, RecO, with and without bound oligonucleotide

    Energy Technology Data Exchange (ETDEWEB)

    Aono, Shelly; Hartsch, Thomas; Schulze-Gahmen, Ursula


    RecFOR proteins are important for DNA repair by homologous recombination in bacteria. The RecO protein from Thermus thermophilus was cloned, purified and characterized for its binding to oligonucleotides. The protein was crystallized alone and in complex with a 14-mer oligonucleotide. Both crystal forms grow under different crystallization conditions in the same space group, P3121 or P3221, with almost identical unit cell parameters. Complete data sets were collected to 2.8 Angstrom and 2.5 Angstrom for RecO alone and the RecO-oligonucleotide complex, respectively. Visual comparison of the diffraction patterns between the two crystal forms and calculation of an Rmerge of 33.9 percent on F indicate that one of the crystal forms is indeed a complex of RecO with bound oligonucleotide.

  20. Interfacing click chemistry with automated oligonucleotide synthesis for the preparation of fluorescent DNA probes containing internal xanthene and cyanine dyes

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Wengel, Jesper


    Double-labeled oligonucleotide probes containing fluorophores interacting by energy-transfer mechanisms are essential for modern bioanalysis, molecular diagnostics, and in vivo imaging techniques. Although bright xanthene and cyanine dyes are gaining increased prominence within these fields, litt...

  1. Lack of clinical pharmacodynamic and pharmacokinetic drug-drug interactions between warfarin and the antisense oligonucleotide mipomersen. (United States)

    Li, Zhaoyang; Hard, Marjie L; Grundy, John S; Singh, Tejdip; von Moltke, Lisa L; Boltje, Ingrid


    Mipomersen is a second-generation antisense oligonucleotide indicated as an adjunct therapy for homozygous familial hypercholesterolemia (HoFH). Warfarin is commonly prescribed for a variety of cardiac disorders in homozygous familial hypercholesterolemia population, and concurrent use of warfarin and mipomersen is likely. This open-label, single-sequence 2-period phase 1 study in healthy subjects evaluated the potential drug-drug interactions between mipomersen and warfarin. The subjects received a single oral 25 mg dose of warfarin alone on day 1, and after a 7-day washout period, received 200 mg mipomersen alone subcutaneously every other day on days 8-12, and received both concurrently on day 14. Coadministration of mipomersen did not change the pharmacodynamics (international normalized ratio, prothrombin time, and activated partial thromboplastin time) and pharmacokinetics (PK) of warfarin. There were no clinically significant changes in the PK of mipomersen with concurrent administration of warfarin. There were no events indicative of an increase in bleeding tendency when warfarin was coadministered with mipomersen, and the adverse event profile of mipomersen did not appear to be altered in combination with warfarin, as compared with that of the respective reference treatment. The combination of these 2 medications appeared to be safe and well tolerated. These results suggest that the dosage adjustment of warfarin or mipomersen is not expected to be necessary with coadministration.

  2. Wild-type mouse models to screen antisense oligonucleotides for exon-skipping efficacy in Duchenne muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Limin Cao

    Full Text Available A readily available animal model is essential for rapidly identifying effective treatments for Duchenne muscular dystrophy (DMD, a devastating neuromuscular disorder caused by the lack of dystrophin protein, which results from frame-disrupting mutations in the DMD gene. Currently, the mdx mouse is the most commonly used model for antisense oligonucleotide (AO-mediated exon skipping pre-clinical studies, with a mild phenotype. However, the accessibility of mdx mouse colonies particularly in developing countries can constrain research. Therefore in this study we explore the feasibility of using wild-type mice as models to establish exon-skipping efficiency of various DMD AO chemistries and their conjugates. Four different strains of wild-type mice and six different AO chemistries were investigated intramuscularly and the results indicated that the same exon-skipping efficiency was achieved for all tested AOs as that from mdx mice. Notably, levels of exon-skipping obtained in C57BL6 and C3H and mdx mice were most closely matched, followed by ICR and BALB/C mice. Systemic validation revealed that wild-type mice are less responsive to AO-mediated exon skipping than mdx mice. Our study provides evidence for the first time that wild-type mice can be appropriate models for assessing DMD AO exon-skipping efficiency with similar sensitivity to that of mdx mice and this finding can further accelerate the development of effective DMD AOs.

  3. Quantum spin model fitting the Yule distribution of oligonucleotides in DNA

    CERN Document Server

    Minichini, C


    A quantum spin chain is identified by the labels of a vector state of a Kashiwara crystal basis. The intensity of the one-spin flip is assumed to depend from the variation of the labels. The rank ordered plot of the numerically computed, averaged in time, transition probabilities is nicely fitted by a Yule distribution, which is the observed distribution of the ranked short oligonucleotides frequency in DNA.

  4. An efficient reagent for the phosphorylation of deoxyribonucleosides, DNA oligonucleotides, and their thermolytic analogues. (United States)

    Ausín, Cristina; Grajkowski, Andrzej; Cieślak, Jacek; Beaucage, Serge L


    [reaction: see text] The phosphoramidite 11 was prepared in three steps from methyl 2-mercaptoacetate and demonstrated efficiency in the synthesis of conventional 5'-/3'-phosphate/thiophosphate monoester derivatives of 2'-deoxyribonucleosides and DNA oligonucleotides. Moreover, the use of 11 has enabled the preparation of the dinucleoside phosphorothioate analogue 26 in high yields (>95%) with minimal cleavage (<2%) of the thermolytic thiophosphate protecting group.

  5. Advances in Antisense Oligonucleotide Development for Target Identification, Validation, and as Novel Therapeutics

    Directory of Open Access Journals (Sweden)

    Moizza Mansoor


    Full Text Available Antisense oligonucleotides (As-ODNs are single stranded, synthetically prepared strands of deoxynucleotide sequences, usually 18–21 nucleotides in length, complementary to the mRNA sequence of the target gene. As-ODNs are able to selectively bind cognate mRNA sequences by sequence-specific hybridization. This results in cleavage or disablement of the mRNA and, thus, inhibits the expression of the target gene. The specificity of the As approach is based on the probability that, in the human genome, any sequence longer than a minimal number of nucleotides (nt, 13 for RNA and 17 for DNA, normally occurs only once. The potential applications of As-ODNs are numerous because mRNA is ubiquitous and is more accessible to manipulation than DNA. With the publication of the human genome sequence, it has become theoretically possible to inhibit mRNA of almost any gene by As-ODNs, in order to get a better understanding of gene function, investigate its role in disease pathology and to study novel therapeutic targets for the diseases caused by dysregulated gene expression. The conceptual simplicity, the availability of gene sequence information from the human genome, the inexpensive availability of synthetic oligonucleotides and the possibility of rational drug design makes As-ODNs powerful tools for target identification, validation and therapeutic intervention. In this review we discuss the latest developments in antisense oligonucleotide design, delivery, pharmacokinetics and potential side effects, as well as its uses in target identification and validation, and finally focus on the current developments of antisense oligonucleotides in therapeutic intervention in various diseases.

  6. Polyimidazole conjugated oligonucleotides reach the nucleus of HeLa cells. (United States)

    Morvan, F; Castex, C; Vivès, E; Imbach, J L


    Oligonucleotide models bearing 6, 12 or 18 histamine residues were synthesized on solid support and labeled with fluorescein. Only the oligo with 6 histamine residues showed a high uptake in HeLa cells with a nuclear localization. Experiment a 4 degrees C or with bafilomicyn A1 suggest that uptake proceeded by an endocytosis mechanism followed by a destabilization of the membrane. Once in the cytoplasm the oligo reached rapidly the nucleus.

  7. Direct Mutagenesis of Thousands of Genomic Targets using Microarray-derived Oligonucleotides

    DEFF Research Database (Denmark)

    Bonde, Mads; Kosuri, Sriram; Genee, Hans Jasper;


    Multiplex Automated Genome Engineering (MAGE) allows simultaneous mutagenesis of multiple target sites in bacterial genomes using short oligonucleotides. However, large-scale mutagenesis requires hundreds to thousands of unique oligos, which are costly to synthesize and impossible to scale-up by ...... insertions per cell. MO-MAGE enables cost-effective large-scale targeted genome engineering that should be useful for a variety of applications in synthetic biology and metabolic engineering....

  8. Modular construction of plasmids through ligation-free assembly of vector components with oligonucleotide linkers. (United States)

    Vroom, Jonathan A; Wang, Clifford L


    We have developed a modular method of plasmid construction that can join multiple DNA components in a single reaction. A nicking enzyme is used to create 5' and 3' overhangs on PCR-generated DNA components. Without the use of ligase or restriction enzymes, components are joined using oligonucleotide linkers that recognize the overhangs. By specifying the sequences of the linkers, desired components can be assembled in any combination and order to generate different plasmid vectors.

  9. Rapid identification of allergenic and pathogenic molds in environmental air by an oligonucleotide array



    Abstract Background Airborne fungi play an important role in causing allergy and infections in susceptible people. Identification of these fungi, based on morphological characteristics, is time-consuming, expertise-demanding, and could be inaccurate. Methods We developed an oligonucleotide array that could accurately identify 21 important airborne fungi (13 genera) that may cause adverse health problems. The method consisted of PCR amplification of the internal transcribed spacer (ITS) region...

  10. Purification of noncoding RNA and bound proteins using FLAG peptide-conjugated antisense-oligonucleotides. (United States)

    Adachi, Shungo; Natsume, Tohru


    To understand the function of certain RNAs, including noncoding RNAs, it is important to identify the proteins that interact with the RNAs. Here we describe the method for purification of ribonucleoprotein (RNP) complexes composed of specific cellular RNAs by pull-down with FLAG peptide-conjugated antisense oligonucleotide (ASO). Using this method, we identified a novel protein component of U7 snRNP complex.

  11. Intrinsically Labeled Fluorescent Oligonucleotide Probes on Quantum Dots for Transduction of Nucleic Acid Hybridization. (United States)

    Shahmuradyan, Anna; Krull, Ulrich J


    Quantum dots (QDs) have been widely used in chemical and biosensing due to their unique photoelectrical properties and are well suited as donors in fluorescence resonance energy transfer (FRET). Selective hybridization interactions of oligonucleotides on QDs have been determined by FRET. Typically, the QD-FRET constructs have made use of labeled targets or have implemented labeled sandwich format assays to introduce dyes in proximity to the QDs for the FRET process. The intention of this new work is to explore a method to incorporate the acceptor dye into the probe molecule. Thiazole orange (TO) derivatives are fluorescent intercalating dyes that have been used for detection of double-stranded nucleic acids. One such dye system has been reported in which single-stranded oligonucleotide probes were doubly labeled with adjacent thiazole orange derivatives. In the absence of the fully complementary (FC) oligonucleotide target, the dyes form an H-aggregate, which results in quenching of fluorescence emission due to excitonic interactions between the dyes. The hybridization of the FC target to the probe provides for dissociation of the aggregate as the dyes intercalate into the double stranded duplex, resulting in increased fluorescence. This work reports investigation of the dependence of the ratiometric signal on the type of linkage used to conjugate the dyes to the probe, the location of the dye along the length of the probe, and the distance between adjacent dye molecules. The limit of detection for 34mer and 90mer targets was found to be identical and was 10 nM (2 pmol), similar to analogous QD-FRET using labeled oligonucleotide target. The detection system could discriminate a one base pair mismatch (1BPM) target and was functional without substantial compromise of the signal in 75% serum. The 1BPM was found to reduce background signal, indicating that the structure of the mismatch affected the environment of the intercalating dyes.

  12. Near-infrared silver cluster optically signaling oligonucleotide hybridization and assembling two DNA hosts. (United States)

    Petty, Jeffrey T; Nicholson, David A; Sergev, Orlin O; Graham, Stuart K


    Silver clusters with ~10 atoms form within DNA strands, and the conjugates are chemical sensors. The DNA host hybridizes with short oligonucleotides, and the cluster moieties optically respond to these analytes. Our studies focus on how the cluster adducts perturb the structure of their DNA hosts. Our sensor is comprised of an oligonucleotide with two components: a 5'-cluster domain that complexes silver clusters and a 3'-recognition site that hybridizes with a target oligonucleotide. The single-stranded sensor encapsulates an ~11 silver atom cluster with violet absorption at 400 nm and with minimal emission. The recognition site hybridizes with complementary oligonucleotides, and the violet cluster converts to an emissive near-infrared cluster with absorption at 730 nm. Our key finding is that the near-infrared cluster coordinates two of its hybridized hosts. The resulting tertiary structure was investigated using intermolecular and intramolecular variants of the same dimer. The intermolecular dimer assembles in concentrated (~5 μM) DNA solutions. Strand stoichiometries and orientations were chromatographically determined using thymine-modified complements that increase the overall conjugate size. The intramolecular dimer develops within a DNA scaffold that is founded on three linked duplexes. The high local cluster concentrations and relative strand arrangements again favor the antiparallel dimer for the near-infrared cluster. When the two monomeric DNA/violet cluster conjugates transform to one dimeric DNA/near-infrared conjugate, the DNA strands accumulate silver. We propose that these correlated changes in DNA structure and silver stoichiometry underlie the violet to near-infrared cluster transformation.

  13. Genome dynamics of short oligonucleotides: the example of bacterial DNA uptake enhancing sequences.

    Directory of Open Access Journals (Sweden)

    Mohammed Bakkali

    Full Text Available Among the many bacteria naturally competent for transformation by DNA uptake-a phenomenon with significant clinical and financial implications- Pasteurellaceae and Neisseriaceae species preferentially take up DNA containing specific short sequences. The genomic overrepresentation of these DNA uptake enhancing sequences (DUES causes preferential uptake of conspecific DNA, but the function(s behind this overrepresentation and its evolution are still a matter for discovery. Here I analyze DUES genome dynamics and evolution and test the validity of the results to other selectively constrained oligonucleotides. I use statistical methods and computer simulations to examine DUESs accumulation in Haemophilus influenzae and Neisseria gonorrhoeae genomes. I analyze DUESs sequence and nucleotide frequencies, as well as those of all their mismatched forms, and prove the dependence of DUESs genomic overrepresentation on their preferential uptake by quantifying and correlating both characteristics. I then argue that mutation, uptake bias, and weak selection against DUESs in less constrained parts of the genome combined are sufficient enough to cause DUESs accumulation in susceptible parts of the genome with no need for other DUES function. The distribution of overrepresentation values across sequences with different mismatch loads compared to the DUES suggests a gradual yet not linear molecular drive of DNA sequences depending on their similarity to the DUES. Other genomically overrepresented sequences, both pro- and eukaryotic, show similar distribution of frequencies suggesting that the molecular drive reported above applies to other frequent oligonucleotides. Rare oligonucleotides, however, seem to be gradually drawn to genomic underrepresentation, thus, suggesting a molecular drag. To my knowledge this work provides the first clear evidence of the gradual evolution of selectively constrained oligonucleotides, including repeated, palindromic and protein

  14. Electrochemical Detection of a Dengue-related Oligonucleotide Sequence Using Ferrocenium as a Hybridization Indicator


    José Luiz de Lima-Filho; Duarte Miguel França dos Prazeres; ernando Rodrigues Ribeiro Teles


    A simple method for electrochemical detection of a synthetic 20-bp oligonucleotide sequence related with dengue virus genome was developed. A complimentary DNA probe sequence was electrostatically immobilized onto a glassy carbon electrode modified with chitosan. Electrochemical detection of hybridization between probe and target was performed by cyclic voltammetry, using ferrocene (Fc+) as a hybridization label. After hybridization, the peak current response of Fc+ oxidation increased around...

  15. Delivering Antisense Morpholino Oligonucleotides to Target Telomerase Splice Variants in Human Embryonic Stem Cells. (United States)

    Radan, Lida; Hughes, Chris S; Teichroeb, Jonathan H; Postovit, Lynne-Marie; Betts, Dean H


    Morpholino oligonucleotides (MO) are an innovative tool that provides a means for examining and modifying gene expression outcomes by antisense interaction with targeted RNA transcripts. The site-specific nature of their binding facilitates focused modulation to alter splice variant expression patterns. Here we describe the steric-blocking of human telomerase reverse transcriptase (hTERT) Δα and Δβ splice variants using MO to examine cellular outcomes related to pluripotency and differentiation in human embryonic stem cells.


    Institute of Scientific and Technical Information of China (English)

    王美琴; 白春学; 钮善福; 方晓惠; 陈常庆; 陈波


    To explore the effect of antisense oligonucleotide on the production of IL-5 by mouse spleen T lymphocytes.Methods Based on the IL-5 cDNA sequence of mouse, a segment of antisense oligonucleotide was designed and synthesized. 5’-labeling of antisense oligonucleotide was signed by T4 PNK in order that the efficiency of stearylamine liposome in transfecting antisense oligonucleotide can be evaluated. Asthma model was duplicated with ovalbumin(OVA) absorbed to aluminum hydroxide. T lymphocytes of mice were separated by nylon fiber method, then T lymphocytes transfected with different concentration of antisense oligonucleotide with cation stearylamine liposme were incubated respectively in order to observe the effect of antisense oligonucleotide on Il-5 production by T lymphocytes. IL-5 levels in the supernatants of T lymphocyte cultures were determined by ELISA.Results Stearylamine liposome could markedly increase the efficiency of antisense oligonucleotide transfection. The transfection efficiency of antisense oligouncleotide increased approximately 12 times at a ratio of 1: 15m/m (antisense oligonucleotide to SA liposome). In healthy and asthma Balb/c mice, IL-5 was not detectable in the supernatants of T lymphocyte cultures without stimulated with OVA; however, IL-5 was increased markedly in the supernatants of T lymphocyte cultures stimulated with OVA. After transfection with different concentrations of antisense oligonucleotide, IL-5 levels in the supernatants of T lymphocyte cultures were significantly lower than those in control cultured without antisense oligonucleotide transfection. IL-5 levels decreased from 44.60±6.23 pg/ml to 30.70±7.362 pg/ml, 17.20±6.181 pg/ml and 8.16±2.34 pg/ml respectively. And IL-5 synthesis was inhibited by 31.17%, 61.43% and 81.7% respectively.Conclusion IL-5 synthesis could be obviously inhibited by antisense oligonucleotide and showed a markedly correlation between dose and effectiveness. It suggests the production

  17. Sm Transition Probabilities and Abundances

    CERN Document Server

    Lawler, J E; Sneden, C; Cowan, J J


    Radiative lifetimes, accurate to +/- 5%, have been measured for 212 odd-parity levels of Sm II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier-transform spectrometry to determine transition probabilities for more than 900 lines of Sm II. This work is the largest-scale laboratory study to date of Sm II transition probabilities using modern methods. This improved data set has been used to determine a new solar photospheric Sm abundance, log epsilon = 1.00 +/- 0.03, from 26 lines. The spectra of three very metal-poor, neutron-capture-rich stars also have been analyzed, employing between 55 and 72 Sm II lines per star. The abundance ratios of Sm relative to other rare earth elements in these stars are in agreement, and are consistent with ratios expected from rapid neutron-capture nucleosynthesis (the r-process).

  18. Element abundances at high redshift

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, D.M.; Welty, D.E.; York, D.G. (Northwestern Univ., Evanston, IL (USA); Chicago Univ., IL (USA))


    Abundances of Si(+), S(+), Cr(+), Mn(+), Fe( ), and Zn(+) are considered for two absorption-line systems in the spectrum of the QSO PKS 0528 - 250. Zinc and sulfur are underabundant, relative to H, by a factor of 10 compared to their solar and Galactic interstellar abundances. The silicon-, chromium-, iron-, and nickel-to-hydrogen ratios are less than the solar values and comparable to the local interstellar ratios. A straightforward interpretation is that nucleosynthesis in these high-redshift systems has led to only about one-tenth as much heavy production as in the gas clouds around the sun, and that the amount of the observed underabundances attributable to grain depletion is small. The dust-to-gas ratio in these clouds is less than 8 percent of the Galactic value. 25 refs.

  19. Element abundances at high redshift (United States)

    Meyer, David M.; Welty, D. E.; York, D. G.


    Abundances of Si(+), S(+), Cr(+), Mn(+), Fe(_), and Zn(+) are considered for two absorption-line systems in the spectrum of the QSO PKS 0528 - 250. Zinc and sulfur are underabundant, relative to H, by a factor of 10 compared to their solar and Galactic interstellar abundances. The silicon-, chromium-, iron-, and nickel-to-hydrogen ratios are less than the solar values and comparable to the local interstellar ratios. A straightforward interpretation is that nucleosynthesis in these high-redshift systems has led to only about one-tenth as much heavy production as in the gas clouds around the sun, and that the amount of the observed underabundances attributable to grain depletion is small. The dust-to-gas ratio in these clouds is less than 8 percent of the Galactic value.

  20. Synthesis of a multibranched porphyrin-oligonucleotide scaffold for the construction of DNA-based nano-architectures. (United States)

    Clavé, Guillaume; Chatelain, Grégory; Filoramo, Arianna; Gasparutto, Didier; Saint-Pierre, Christine; Le Cam, Eric; Piétrement, Olivier; Guérineau, Vincent; Campidelli, Stéphane


    The interest in the functionalization of oligonucleotides with organic molecules has grown considerably over the last decade. In this work, we report on the synthesis and characterization of porphyrin-oligonucleotide hybrids containing one to four DNA strands (P1-P4). The hybrid P4, which inserts one porphyrin and four DNA fragments, was combined with gold nanoparticles and imaged by transmission electron microscopy.

  1. Thermolytic CpG-containing DNA oligonucleotides as potential immunotherapeutic prodrugs. (United States)

    Grajkowski, Andrzej; Pedras-Vasconcelos, Joao; Wang, Vivian; Ausín, Cristina; Hess, Sonja; Verthelyi, Daniela; Beaucage, Serge L


    A CpG-containing DNA oligonucleotide functionalized with the 2-(N-formyl-N-methyl)aminoethyl thiophosphate protecting group (CpG ODN fma1555) was prepared from phosphoramidites 1a-d using solid-phase techniques. The oligonucleotide behaved as a prodrug by virtue of its conversion to the well-studied immunomodulatory CpG ODN 1555 through thermolytic cleavage of the 2-(N-formyl-N-methyl)aminoethyl thiophosphate protecting group. Such a conversion occurred at 37 degrees C with a half-time of 73 h. The immunostimulatory properties of CpG ODN fma1555 were evaluated in two in vivo assays, one of which consisted of mice challenged in the ear with live Leishmania major metacyclic promastigotes. Local intradermal administration of CpG ODN fma1555 was as effective as that of CpG ODN 1555 in reducing the size of Leishmania lesions over time. In a different infectious model, CpG ODN 1555 prevented the death of Tacaribe-infected mice (43% survival) when administered between day 0 and 3 post infection. Administration of CpG ODN fma1555 three days before infection resulted in improved immunoprotection (60-70% survival). Moreover, co-administration of CpG ODN fma1555 and CpG ODN 1555 in this model increased the window for therapeutic treatment against Tacaribe virus infection, and thus supports the use of thermolytic oligonucleotides as prodrugs in the effective treatment of infectious diseases.

  2. Sequence-specific targeting of RNA with an oligonucleotide-neomycin conjugate. (United States)

    Charles, Irudayasamy; Xi, Hongjuan; Arya, Dev P


    The synthesis of neomycin covalently attached at the C5-position of 2'-deoxyuridine is reported. The synthesis outlined allows for incorporation of an aminoglycoside (neomycin) at any given site in an oligonucleotide (ODN) where a thymidine (or uridine) is present. Incorporation of this modified base into an oligonucleotide, which is complementary to a seven-bases-long alpha-sarcin loop RNA sequence, leads to enhanced duplex hybridization. The increase in Tm for this duplex (DeltaTm = 6 degrees C) suggests a favorable interaction of neomycin within the duplex groove. CD spectroscopy shows that the modified duplex adopts an A-type confirmation. ITC measurements indicate the additive effects of ODN and neomycin binding to the RNA target (Ka = 4.5 x 107 M-1). The enhanced stability of the hybrid duplex from this neomycin-ODN conjugate originates primarily from the enthalpic contribution of neomycin {DeltaDeltaHobs = -7.21 kcal/mol (DeltaHneomycin conjugated - DeltaH nonconjugated)} binding to the hybrid duplex. The short linker length allows for selective stabilization of the hybrid duplex over the hybrid triplex. The results described here open up new avenues in the design and synthesis of nucleo-aminoglycoside-conjugates (N-Ag-C) where the inclusion of any number of aminoglycoside (neomycin) molecules per oligonucleotide can be accomplished.

  3. Detection of Glucose with Atomic Absorption Spectroscopy by Using Oligonucleotide Functionalized Gold Nanoparticle. (United States)

    Zhang, Hong; Yan, Honglian; Ling, Liansheng


    A novel method for the detection of glucose was established with atomic absorption spectroscopy by using the label of gold nanoparticle (AuNP). Silver-coated glass assembled with oligonucleotide 5'-SH-T12-AGA CAA GAG AGG-3' (Oligo 1) was acted as separation probe, oligonucleotide 5'-CAA CAG AGA ACG-T12-SH-3' modified gold nanoparticle (AuNP-Oligo 2) was acted as signal-reporting probe. Oligonucleotide 5'-CGT TCT CTG TTG CCT CTC TTG TCT-3' (Oligo 3) could hybridize with Oligo 1 on the surface of silver-coated glass and AuNP-Oligo 2, and free AuNP-Oligo 2 could be removed by rinsing with buffer. Hence the concentration of Oligo 3 was transformed into the concentration of gold element. In addition, Oligo 3 could be cleaved into DNA fragments by glucose, glucose oxidase and Fe(2+)-EDTA through Fenton reaction. Thereby the concentration of glucose could be transformed to the absorbance of gold element. Under the optimum conditions, the integrated absorbance decreased proportionally to the concentration of glucose over the range from 50.0 μM to 1.0 mM with a detection limit of 40.0 μM. Moreover, satisfactory result was obtained when the assay was used to determinate glucose in human serum.

  4. Membrane-based oligonucleotide array developed from multiple markers for the detection of many Phytophthora species. (United States)

    Chen, Wen; Djama, Zeinab Robleh; Coffey, Michael D; Martin, Frank N; Bilodeau, Guillaume J; Radmer, Lorien; Denton, Geoff; Lévesque, C André


    Most Phytophthora spp. are destructive plant pathogens; therefore, effective monitoring and accurate early detection are important means of preventing potential epidemics and outbreaks of diseases. In the current study, a membrane-based oligonucleotide array was developed that can detect Phytophthora spp. reliably using three DNA regions; namely, the internal transcribed spacer (ITS), the 5' end of cytochrome c oxidase 1 gene (cox1), and the intergenic region between cytochrome c oxidase 2 gene (cox2) and cox1 (cox2-1 spacer). Each sequence data set contained ≈250 sequences representing 98 described and 15 undescribed species of Phytophthora. The array was validated with 143 pure cultures and 35 field samples. Together, nonrejected oligonucleotides from all three markers have the ability to reliably detect 82 described and 8 undescribed Phytophthora spp., including several quarantine or regulated pathogens such as Phytophthora ramorum. Our results showed that a DNA array containing signature oligonucleotides designed from multiple genomic regions provided robustness and redundancy for the detection and differentiation of closely related taxon groups. This array has the potential to be used as a routine diagnostic tool for Phytophthora spp. from complex environmental samples without the need for extensive growth of cultures.

  5. Molecular phylogenetics before sequences: oligonucleotide catalogs as k-mer spectra. (United States)

    Ragan, Mark A; Bernard, Guillaume; Chan, Cheong Xin


    From 1971 to 1985, Carl Woese and colleagues generated oligonucleotide catalogs of 16S/18S rRNAs from more than 400 organisms. Using these incomplete and imperfect data, Carl and his colleagues developed unprecedented insights into the structure, function, and evolution of the large RNA components of the translational apparatus. They recognized a third domain of life, revealed the phylogenetic backbone of bacteria (and its limitations), delineated taxa, and explored the tempo and mode of microbial evolution. For these discoveries to have stood the test of time, oligonucleotide catalogs must carry significant phylogenetic signal; they thus bear re-examination in view of the current interest in alignment-free phylogenetics based on k-mers. Here we consider the aims, successes, and limitations of this early phase of molecular phylogenetics. We computationally generate oligonucleotide sets (e-catalogs) from 16S/18S rRNA sequences, calculate pairwise distances between them based on D 2 statistics, compute distance trees, and compare their performance against alignment-based and k-mer trees. Although the catalogs themselves were superseded by full-length sequences, this stage in the development of computational molecular biology remains instructive for us today.

  6. Efficient delivery of RNA interference oligonucleotides to polarized airway epithelia in vitro. (United States)

    Ramachandran, Shyam; Krishnamurthy, Sateesh; Jacobi, Ashley M; Wohlford-Lenane, Christine; Behlke, Mark A; Davidson, Beverly L; McCray, Paul B


    Polarized and pseudostratified primary airway epithelia present barriers that significantly reduce their transfection efficiency and the efficacy of RNA interference oligonucleotides. This creates an impediment in studies of the airway epithelium, diminishing the utility of loss-of-function as a research tool. Here we outline methods to introduce RNAi oligonucleotides into primary human and porcine airway epithelia grown at an air-liquid interface and difficult-to-transfect transformed epithelial cell lines grown on plastic. At the time of plating, we reverse transfect small-interfering RNA (siRNA), Dicer-substrate siRNA, or microRNA oligonucleotides into cells by use of lipid or peptide transfection reagents. Using this approach we achieve significant knockdown in vitro of hypoxanthine-guanine phosphoribosyltransferase, IL-8, and CFTR expression at the mRNA and protein levels in 1-3 days. We also attain significant reduction of secreted IL-8 in polarized primary pig airway epithelia 3 days posttransfection and inhibition of CFTR-mediated Cl⁻ conductance in polarized air-liquid interface cultures of human airway epithelia 2 wk posttransfection. These results highlight an efficient means to deliver RNA interference reagents to airway epithelial cells and achieve significant knockdown of target gene expression and function. The ability to reliably conduct loss-of-function assays in polarized primary airway epithelia offers benefits to research in studies of epithelial cell homeostasis, candidate gene function, gene-based therapeutics, microRNA biology, and targeting the replication of respiratory viruses.

  7. Antisense oligonucleotides as innovative therapeutic strategy in the treatment of high-grade gliomas. (United States)

    Caruso, Gerardo; Caffo, Mariella; Raudino, Giuseppe; Alafaci, Concetta; Salpietro, Francesco M; Tomasello, Francesco


    Despite the intensive recent research in cancer therapy, the prognosis in patients affected by high-grade gliomas is still very unfavorable. The efficacy of classical anti-cancer strategies is seriously limited by lack of specific therapies against malignant cells. The extracellular matrix plays a pivotal role in processes such as differentiation, apoptosis, and migration in both the normal and the pathologic nervous system. Glial tumors seem to be able to create a favorable environment for the invasion of glioma cells in cerebral parenchyma when they combine with the extracellular matrix via cell surface receptors. Glioma cells synthesize matrix proteins, such as tenascin, laminin, fibronectin that facilitate the tumor cell's motility. New treatments have shown to hit the acting molecules in the tumor growth and to increase the efficacy and minimize the toxicity. Antisense oligonucleotides are synthetic stretches of DNA which hybridize with specific mRNA strands. The specificity of hybridization makes antisense method an interesting strategy to selectively modulate the expression of genes involved in tumorigenesis. In this review we will focus on the mechanisms of action of antisense oligonucleotides and report clinical and experimental studies on the treatment of high-grade gliomas. We will also report the patents of preclinical and/or clinical studies that adopt the antisense oligonucleotide therapy list in cerebral gliomas.

  8. Immunostimulatory oligonucleotide, CpG-like motif exists in Lactobacillus delbrueckii ssp. bulgaricus NIAI B6. (United States)

    Kitazawa, Haruki; Watanabe, Hiroshi; Shimosato, Takeshi; Kawai, Yasushi; Itoh, Takatoshi; Saito, Tadao


    The present study was conducted to find an immunostimulatory oligonucleotide derived from yogurt starter cultures. The chromosomal DNA was purified from nine strains of Lactobacillus delbrueckii ssp. bulgaricus and six strains of Streptococcus thermophilus. An immunostimulatory ability of the DNA was examined in a proliferation of peyer's patch and splenic B cells. Only the DNA from L. bulgaricus NIAI B6 induced a significant proliferation of both cells. When the DNA was cloned and amplified using PCR, the mitogenic activities to B cells were significantly increased by 13 of 135 DNA clones. Ten homologous nucleotide sequences were found as possible oligonucleotide sequences of mitogens, and were then chemically synthesized (sOL-LB1 to sOL-LB10). One CpG-like motif (sOL-LB7; 5'-CGGCACGCTCACGATTCTTG-3') was identified as an immunostimulatory oligonucleotide, but it did not contain palindromic CpG structure known as a B cell-specific mitogen. The sOL-LB7 substantially bound to B cells and increased the CD69 positive cells in peyer's patch cells. This study demonstrated that L. bulgaricus NIAI B6 was a good candidate of a starter culture for the production of new functional foods, "Bio-Defense Foods".

  9. ProbeMaker: an extensible framework for design of sets of oligonucleotide probes

    Directory of Open Access Journals (Sweden)

    Nilsson Mats


    Full Text Available Abstract Background Procedures for genetic analyses based on oligonucleotide probes are powerful tools that can allow highly parallel investigations of genetic material. Such procedures require the design of large sets of probes using application-specific design constraints. Results ProbeMaker is a software framework for computer-assisted design and analysis of sets of oligonucleotide probe sequences. The tool assists in the design of probes for sets of target sequences, incorporating sequence motifs for purposes such as amplification, visualization, or identification. An extension system allows the framework to be equipped with application-specific components for evaluation of probe sequences, and provides the possibility to include support for importing sequence data from a variety of file formats. Conclusion ProbeMaker is a suitable tool for many different oligonucleotide design and analysis tasks, including the design of probe sets for various types of parallel genetic analyses, experimental validation of design parameters, and in silico testing of probe sequence evaluation algorithms.

  10. Efficient inhibition of human telomerase activity by antisense oligonucleotides sensitizes cancer cells to radiotherapy

    Institute of Scientific and Technical Information of China (English)

    Xue-mei JI; Cong-hua XIE; Ming-hao FANG; Fu-xiang ZHOU; Wen-jie ZHANG; Ming-sheng ZHANG; Yun-feng ZHOU


    Aim: To investigate the effect of the antisense oligonucleotides (ASODN) specific for human telomerase RNA (hTR) on radio sensitization and proliferation inhibition in human neurogliocytoma cells (U251). Methods: U251 cells were transfected with hTR ASODN or nonspecific oligonucleotides (NSODN). Before and after irradiation of 60Co-γray, telomerase activity was assayed by telomeric repeat amplification protocol (TRAP-PCR-ELISA), and DNA damage and repair were examined by the comet assay. The classical colony assay was used to plot the cell-survival curve, to detect the D0 value. Results: hTR antisense oligonucleotides could downregulate the telomerase activity, increase radiation induced DNA damage and reduce the subsequent repair. Furthermore, it could inhibit the proliferation and decrease the D0 value which demonstrates rising radiosensitivity. However, telomere length was unchanged over a short period of time. Conclusion: These findings suggest that an ASODN-based strategy may be used to develop telomerase inhibitors, which can efficiently sensitize radiotherapy.

  11. Abundance analysis of Barium stars

    Institute of Scientific and Technical Information of China (English)

    Guo-Qing Liu; Yan-Chun Liang; Li-Cai Deng


    We obtain the chemical abundances of six barium stars and two CH subgiant stars based on the high signal-to-noise ratio and high resolution Echelle spectra. The neu- tron capture process elements Y, Zr, Ba, La and Eu show obvious overabundances relative to the Sun, for example, their [Ba/Fe] values are from 0.45 to 1.27. Other elements, in- cluding Na, Mg, A1, Si, Ca, Sc, Ti, V, Cr, Mn and Ni, show comparable abundances to the Solar ones, and their [Fe/H] covers a range from -0.40 to 0.21, which means they belong to the Galactic disk. The predictions of the theoretical model of wind accretion for bi- nary systems can explain the observed abundance patterns of the neutron capture process elements in these stars, which means that their overabundant heavy-elements could be caused by accreting the ejecta of AGB stars, the progenitors of present-day white dwarf companions in binary systems.

  12. Abundance Anomalies In Tidal Disruption Events

    CERN Document Server

    Kochanek, C S


    The ~10% of tidal disruption events (TDEs) due to stars more massive than the Sun should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ~25% on average because it becomes inaccessible once it is sequestered in the high density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main sequence star can be enhanced in helium by factors of 2-3 for debris at a common orbital period. These helium abundance variations may be a contributor to the observed diversity of hydrogen and helium line strengths in TDEs. A still more striking anomaly is the rapid enhancement of nitrogen and the depletion of carbon due to the CNO cycle -- stars more massive than the Sun quickly show an increase in their average N/C ratio by factors of 3-10. Because low mass stars evolve slowly and high mass stars are rare, TDEs showing high N/C will almost all be due to 1-2Msun stars disr...

  13. How ants drop out: ant abundance on tropical mountains.

    Directory of Open Access Journals (Sweden)

    John T Longino

    Full Text Available In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica and examined the impact of elevation (as a proxy for temperature and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops.

  14. Discovery and development of the G-rich oligonucleotide AS1411 as a novel treatment for cancer. (United States)

    Bates, Paula J; Laber, Damian A; Miller, Donald M; Thomas, Shelia D; Trent, John O


    Certain guanine-rich (G-rich) DNA and RNA molecules can associate intermolecularly or intramolecularly to form four stranded or "quadruplex" structures, which have unusual biophysical and biological properties. Several synthetic G-rich quadruplex-forming oligodeoxynucleotides have recently been investigated as therapeutic agents for various human diseases. We refer to these biologically active G-rich oligonucleotides as aptamers because their activities arise from binding to protein targets via shape-specific recognition (analogous to antibody-antigen binding). As therapeutic agents, the G-rich aptamers may have some advantages over monoclonal antibodies and other oligonucleotide-based approaches. For example, quadruplex oligonucleotides are non-immunogenic, heat stable and they have increased resistance to serum nucleases and enhanced cellular uptake compared to unstructured sequences. In this review, we describe the characteristics and activities of G-rich oligonucleotides. We also give a personal perspective on the discovery and development of AS1411, an antiproliferative G-rich phosphodiester oligonucleotide that is currently being tested as an anticancer agent in Phase II clinical trials. This molecule functions as an aptamer to nucleolin, a multifunctional protein that is highly expressed by cancer cells, both intracellularly and on the cell surface. Thus, the serendipitous discovery of the G-rich oligonucleotides also led to the identification of nucleolin as a new molecular target for cancer therapy.

  15. Thermolytic 4-methylthio-1-butyl group for phosphate/thiophosphate protection in solid-phase synthesis of DNA oligonucleotides. (United States)

    Cieślak, Jacek; Grajkowski, Andrzej; Livengood, Victor; Beaucage, Serge L


    The thermolabile 4-methylthio-1-butyl phosphate/thiophosphate protecting group for DNA oligonucleotides has been investigated for its potential application to a "heat-driven" process for either oligonucleotide synthesis on diagnostic microarrays or, oppositely, to the large-scale preparation of therapeutic oligonucleotides. The preparation of phosphoramidites 10a-d is straightforward, and the incorporation of these amidites into oligonucleotides via solid-phase techniques proceeds as efficiently as that achieved with 2-cyanoethyl deoxyribonucleoside phosphoramidites. The versatility of the 4-methylthio-1-butyl phosphate/thiophosphate protecting group is exemplified by its facile removal from oligonucleotides upon heating for 30 min at 55 degrees C in an aqueous buffer under neutral conditions or within 2 h at 55 degrees C in concentrated NH(4)OH. The deprotection reaction occurs through an intramolecular cyclodeesterification mechanism leading to the formation of sulfonium salt 18. When mixed with deoxyribonucleosides and N-protected 2'-deoxyribonucleosides or with a model phosphorothioate diester under conditions approximating those of large-scale (>50 mmol) oligonucleotide deprotection reactions, the salt 18 did not significantly alter DNA nucleobases or desulfurize the phosphorothioate diester model to an appreciable extent.

  16. Oligonucleotide and Parylene Surface Coating of Polystyrene and ePTFE for Improved Endothelial Cell Attachment and Hemocompatibility

    Directory of Open Access Journals (Sweden)

    Martina Schleicher


    Full Text Available In vivo self-endothelialization by endothelial cell adhesion on cardiovascular implants is highly desirable. DNA-oligonucleotides are an intriguing coating material with nonimmunogenic characteristics and the feasibility of easy and rapid chemical fabrication. The objective of this study was the creation of cell adhesive DNA-oligonucleotide coatings on vascular implant surfaces. DNA-oligonucleotides immobilized by adsorption on parylene (poly(monoaminomethyl-para-xylene coated polystyrene and ePTFE were resistant to high shear stress (9.5 N/m2 and human blood serum for up to 96 h. Adhesion of murine endothelial progenitor cells, HUVECs and endothelial cells from human adult saphenous veins as well as viability over a period of 14 days of HUVECs on oligonucleotide coated samples under dynamic culture conditions was significantly enhanced (P<0.05. Oligonucleotide-coated surfaces revealed low thrombogenicity and excellent hemocompatibility after incubation with human blood. These properties suggest the suitability of immobilization of DNA-oligonucleotides for biofunctionalization of blood vessel substitutes for improved in vivo endothelialization.

  17. Forms and genesis of species abundance distributions

    Directory of Open Access Journals (Sweden)

    Evans O. Ochiaga


    Full Text Available Species abundance distribution (SAD is one of the most important metrics in community ecology. SAD curves take a hollow or hyperbolic shape in a histogram plot with many rare species and only a few common species. In general, the shape of SAD is largely log-normally distributed, although the mechanism behind this particular SAD shape still remains elusive. Here, we aim to review four major parametric forms of SAD and three contending mechanisms that could potentially explain this highly skewed form of SAD. The parametric forms reviewed here include log series, negative binomial, lognormal and geometric distributions. The mechanisms reviewed here include the maximum entropy theory of ecology, neutral theory and the theory of proportionate effect.

  18. Thermolytic release of covalently linked DNA oligonucleotides and their conjugates from controlled-pore glass at near neutral pH. (United States)

    Grajkowski, Andrzej; Cieślak, Jacek; Kauffman, Jon S; Duff, Robert J; Norris, Scott; Freedberg, Darón I; Beaucage, Serge L


    The functionalization of long chain alkylamine controlled-pore glass (CPG) with a 3-hydroxypropyl-(2-cyanoethyl)thiophosphoryl linker and its conversion to the support 7 has led to the synthesis of DNA oligonucleotides and their 3'- or (3',5')-conjugates. Indeed, CPG support 7 has been successfully employed in the synthesis of both native and fully phosphorothioated DNA 20-mers. Unlike conventional succinylated CPG supports, this distinctively functionalized support allows oligonucleotide deprotection and removal of the deprotection side products to proceed without releasing the oligonucleotide into the aqueous milieu. When freed from deprotection side products, the DNA oligonucleotide is thermolytically released from the support within 2 h under nearly neutral conditions (pH 7.2, 90 degrees C). The quality of these oligonucleotides is comparable to that of identical oligonucleotides synthesized from succinylated CPG supports in terms of shorter than full length oligonucleotide contaminants and overall yields. The versatility of the thermolytic CPG support 7 is further demonstrated by the synthesis of a DNA oligonucleotide (20-mer) and its conjugation with an azido and alkynyl groups at both 5'-and 3'-termini, respectively. The functionality of the (3',5')-heteroconjugated oligonucleotide 18 is verified by its circularization to the DNA oligonucleotide 19 under "click" chemistry conditions.

  19. Synthesis of Biotin Linkers with the Activated Triple Bond Donor [p-(N-propynoylaminotoluic Acid] (PATA for Efficient Biotinylation of Peptides and Oligonucleotides

    Directory of Open Access Journals (Sweden)

    Martina Jezowska


    Full Text Available Biotin is an important molecule for modern biological studies including, e.g., cellular transport. Its exclusive affinity to fluorescent streptavidin/avidin proteins allows ready and specific detection. As a consequence methods for the attachment of biotin to various biological targets are of high importance, especially when they are very selective and can also proceed in water. One useful method is Hüisgen dipolar [3+2]-cycloaddition, commonly referred to as “click chemistry”. As we reported recently, the activated triple bond donor p-(N-propynoylaminotoluic acid (PATA gives excellent results when used for conjugations at submicromolar concentrations. Thus, we have designed and synthesized two biotin linkers, with different lengths equipped with this activated triple bond donor and we proceeded with biotinylation of oligonucleotides and C-myc peptide both in solution and on solid support with excellent yields of conversion.

  20. Dry-reagent disposable biosensor for visual genotyping of single nucleotide polymorphisms by oligonucleotide ligation reaction: application to pharmacogenetic analysis. (United States)

    Toubanaki, Dimitra K; Christopoulos, Theodore K; Ioannou, Penelope C; Gravanis, Achille


    Most genotyping methods for known single-nucleotide polymorphisms (SNPs) are based on hybridization with allele-specific probes, oligonucleotide ligation reaction (OLR), primer extension or invasive cleavage. OLR offers superior specificity because it involves two recognition events; namely, the hybridization of an allele-specific probe and a common probe to adjacent positions on target DNA. OLR products can be detected by microtiter well-based colorimetric, time-resolved fluorimetric or chemiluminometric assays, electrophoresis, microarrays, microspheres, and homogeneous fluorimetric or colorimetric assays. We have developed a simple, robust, and low-cost disposable biosensor in dry-reagent format, which allows visual genotyping with no need for instrumentation. The OLR mixture contains a biotinylated common probe and an allele-specific probe with a (dA)(20) segment at the 3'-end. OLR products are denatured and applied to the biosensor next to gold nanoparticles that are decorated with oligo(dT) strands. The sensor is immersed in the appropriate buffer and all components migrate by capillary action. The OLR product is captured by immobilized streptavidin at the test zone (TZ) of the sensor and hybridizes with the oligo(dT) strands of the nanoparticles. A characteristic red line is generated due to the accumulation of nanoparticles. The excess nanoparticles are captured by immobilized oligo(dA) at the control zone of the strip, giving a second red line. We have applied successfully the proposed OLR-dipstick assay to the genotyping of four SNPs in the drug-metabolizing enzyme genes CYP2D6 ((*)3 and (*)4) and CYP2C19 ((*)2 and (*)3). The results were in agreement with direct sequencing.

  1. Lead abundance in the uranium star CS 31082-001

    DEFF Research Database (Denmark)

    Plez, B.; Hill, V.; Cayrel, R.;


    stars:abundances- physical data and processes: nuclear reactions, nucleosynthesis, abundances- atomic data......stars:abundances- physical data and processes: nuclear reactions, nucleosynthesis, abundances- atomic data...

  2. Surface abundances of ON stars

    CERN Document Server

    Martins, F; Palacios, A; Howarth, I; Georgy, C; Walborn, N R; Bouret, J -C; Barba, R


    Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient, or when mass transfer in binary systems happens, chemically processed material is observed at the surface of O and B stars. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle or not is not known. Our goal is to answer this question. We perform a spectroscopic analysis of a sample of ON stars with atmosphere models. We determine the fundamental parameters as well as the He, C, N, and O surface abundances. We also measure the projected rotational velocities. We compare the properties of the ON stars to those of normal O stars. We show that ON stars are usually helium-rich. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cann...

  3. [Commemorative lecture of receiving Imamura Memorial Prize. II. Mode of action of oligonucleotide fraction extracted from Mycobacterium bovis BCG]. (United States)

    Yamamoto, S


    A fraction extracted from Mycobacterium bovis BCG was found to exhibit strong antitumor activity. This fraction, which was designated MY-1, caused some animal tumors to regress and/or prevent metastasis very effectively. MY-1 after digestion with DNase had almost completely reduced activity, while MY-1 digested with RNase did not. MY-1 also augmented natural killer (NK) cell activity of mouse spleen cells in vitro, and produced factors which showed anti-viral activity and rendered macrophages cytotoxic towards tumor cells. The function of the factor to activate macrophages was destroyed by treatment with anti-interferon (IFN)-gamma antibody, while the anti-viral activity was destroyed by treatment with anti-INF alpha/beta antibody. The oligonucleotides contained in MY-1 distributed in a broad range of molecular size, and peaked at 45 nucleotides. We synthesized 13 kinds of 45-mer nucleotides with sequence present in the known cDNA encoding various BCG proteins. Six out of these oligonucleotides, which contained one or more hexameric palindromic structures, showed strong antitumor activity, while the other without palindrome did not. These active oligonucleotides possessed the capability to induce IFN and to augment NK cell activity of mouse spleen cells by coincubation in vitro. When a portion of the sequence of the inactive oligonucleotides was substituted with either palindromic sequence of GACGTC, AGCGCT or AACGTT, the oligonucleotide acquired the ability to augment NK activity. In contrast, the oligonucleotides substituted with another palindromic sequence such as ACCGGT was without effect. Furthermore, exchange of two neighboring mononucleotides within, but not outside, the active palindromic sequence destroyed the ability of the oligonucleotide to augment NK activity.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Commonness and rarity in the marine biosphere. (United States)

    Connolly, Sean R; MacNeil, M Aaron; Caley, M Julian; Knowlton, Nancy; Cripps, Ed; Hisano, Mizue; Thibaut, Loïc M; Bhattacharya, Bhaskar D; Benedetti-Cecchi, Lisandro; Brainard, Russell E; Brandt, Angelika; Bulleri, Fabio; Ellingsen, Kari E; Kaiser, Stefanie; Kröncke, Ingrid; Linse, Katrin; Maggi, Elena; O'Hara, Timothy D; Plaisance, Laetitia; Poore, Gary C B; Sarkar, Santosh K; Satpathy, Kamala K; Schückel, Ulrike; Williams, Alan; Wilson, Robin S


    Explaining patterns of commonness and rarity is fundamental for understanding and managing biodiversity. Consequently, a key test of biodiversity theory has been how well ecological models reproduce empirical distributions of species abundances. However, ecological models with very different assumptions can predict similar species abundance distributions, whereas models with similar assumptions may generate very different predictions. This complicates inferring processes driving community structure from model fits to data. Here, we use an approximation that captures common features of "neutral" biodiversity models--which assume ecological equivalence of species--to test whether neutrality is consistent with patterns of commonness and rarity in the marine biosphere. We do this by analyzing 1,185 species abundance distributions from 14 marine ecosystems ranging from intertidal habitats to abyssal depths, and from the tropics to polar regions. Neutrality performs substantially worse than a classical nonneutral alternative: empirical data consistently show greater heterogeneity of species abundances than expected under neutrality. Poor performance of neutral theory is driven by its consistent inability to capture the dominance of the communities' most-abundant species. Previous tests showing poor performance of a neutral model for a particular system often have been followed by controversy about whether an alternative formulation of neutral theory could explain the data after all. However, our approach focuses on common features of neutral models, revealing discrepancies with a broad range of empirical abundance distributions. These findings highlight the need for biodiversity theory in which ecological differences among species, such as niche differences and demographic trade-offs, play a central role.

  5. Synthetic oligonucleotides with particular base sequences from the cDNA encoding proteins of Mycobacterium bovis BCG induce interferons and activate natural killer cells. (United States)

    Tokunaga, T; Yano, O; Kuramoto, E; Kimura, Y; Yamamoto, T; Kataoka, T; Yamamoto, S


    Thirteen kinds of 45-mer single-stranded oligonucleotide, having sequence randomly selected from the known cDNA encoding BCG proteins, were tested for their capability to augment natural killer (NK) cell activity of mouse spleen cells in vitro. Six out of the 13 oligonucleotides showed the activity, while the others did not. In order to know the minimal and essential sequence(s) responsible for the biological activity, 2 kinds of 30-mer and 5 kinds of 15-mer oligonucleotide fragments of an active 45-mer nucleotide were tested for their activity. One of the 30-mer oligonucleotides, designated BCG-A4a, was active, but the other 30-mer was inactive. All of the 15-mer oligonucleotide fragments were inactive. The BCG-A4a also stimulated the spleen cells to produce interferon (IFN)-alpha and -gamma. An experiment using anti-IFN antisera showed that the NK cell activation by the oligonucleotide was ascribed to the IFN-alpha produced. It was noticed that all of the biologically active oligonucleotides possessed one or more palindrome sequence(s), and the inactive ones did not, with an exception of a 45-mer inactive oligonucleotide containing overlapping palindrome sequences (GGGCCCGGG). These findings strongly suggest that certain palindrome sequences, like GACGTC, GGCGCC and TGCGCA, are essential for 30-mer oligonucleotides, like BCG-A4a, to induce IFNs.

  6. Detection of fluorescent labelled oligonucleotides using oxalate chemiluminiscence. Estudio de la deteccion de oligonucleotidos marcados con compuestos fluorescentes utilizando la quimioluminiscencia de los esteres del acido oxalico

    Energy Technology Data Exchange (ETDEWEB)

    Eritia, R. (Barcelona Univ. (Spain). Dept. de Quimica Organica); Johnson, D.; Paige, J.; Walker, P.; Kaplan, B. (Beckman Research Institute of City of Hope, CA (USA))


    The preparation and characterization of oligonucleotides containing fluorescent compounds at the 5' terminus is described together with the utilization of oxalate chemiluminiscence for their detection. (Author)

  7. Detection of cyclin D1 mRNA by hybridization sensitive NIC-oligonucleotide probe. (United States)

    Kovaliov, Marina; Segal, Meirav; Kafri, Pinhas; Yavin, Eylon; Shav-Tal, Yaron; Fischer, Bilha


    A large group of fluorescent hybridization probes, includes intercalating dyes for example thiazole orange (TO). Usually TO is coupled to nucleic acids post-synthetically which severely limits its use. Here, we have developed a phosphoramidite monomer, 10, and prepared a 2'-OMe-RNA probe, labeled with 5-(trans-N-hexen-1-yl-)-TO-2'-deoxy-uridine nucleoside, dU(TO), (Nucleoside bearing an Inter-Calating moiety, NIC), for selective mRNA detection. We investigated a series of 15-mer 2'-OMe-RNA probes, targeting the cyclin D1 mRNA, containing one or several dU(TO) at various positions. dU(TO)-2'-OMe-RNA exhibited up to 7-fold enhancement of TO emission intensity upon hybridization with the complementary RNA versus that of the oligomer alone. This NIC-probe was applied for the specific detection of a very small amount of a breast cancer marker, cyclin D1 mRNA, in total RNA extract from cancerous cells (250 ng/μl). Furthermore, this NIC-probe was found to be superior to our related NIF (Nucleoside with Intrinsic Fluorescence)-probe which could detect cyclin D1 mRNA target only at high concentrations (1840 ng/μl). Additionally, dU(T) can be used as a monomer in solid-phase oligonucleotide synthesis, thus avoiding the need for post-synthetic modification of oligonucleotide probes. Hence, we propose dU(TO) oligonucleotides, as hybridization probes for the detection of specific RNA in homogeneous solutions and for the diagnosis of breast cancer.

  8. Development and production of an oligonucleotide MuscleChip: use for validation of ambiguous ESTs

    Directory of Open Access Journals (Sweden)

    Lanfranchi Gerolamo


    Full Text Available Abstract Background We describe the development, validation, and use of a highly redundant 120,000 oligonucleotide microarray (MuscleChip containing 4,601 probe sets representing 1,150 known genes expressed in muscle and 2,075 EST clusters from a non-normalized subtracted muscle EST sequencing project (28,074 EST sequences. This set included 369 novel EST clusters showing no match to previously characterized proteins in any database. Each probe set was designed to contain 20–32 25 mer oligonucleotides (10–16 paired perfect match and mismatch probe pairs per gene, with each probe evaluated for hybridization kinetics (Tm and similarity to other sequences. The 120,000 oligonucleotides were synthesized by photolithography and light-activated chemistry on each microarray. Results Hybridization of human muscle cRNAs to this MuscleChip (33 samples showed a correlation of 0.6 between the number of ESTs sequenced in each cluster and hybridization intensity. Out of 369 novel EST clusters not showing any similarity to previously characterized proteins, we focused on 250 EST clusters that were represented by robust probe sets on the MuscleChip fulfilling all stringent rules. 102 (41% were found to be consistently "present" by analysis of hybridization to human muscle RNA, of which 40 ESTs (39% could be genome anchored to potential transcription units in the human genome sequence. 19 ESTs of the 40 ESTs were furthermore computer-predicted as exons by one or more than three gene identification algorithms. Conclusion Our analysis found 40 transcriptionally validated, genome-anchored novel EST clusters to be expressed in human muscle. As most of these ESTs were low copy clusters (duplex and triplex in the original 28,000 EST project, the identification of these as significantly expressed is a robust validation of the transcript units that permits subsequent focus on the novel proteins encoded by these genes.

  9. Effect of Terminal Groups of Dendrimers in the Complexation with Antisense Oligonucleotides and Cell Uptake. (United States)

    Márquez-Miranda, Valeria; Peñaloza, Juan Pablo; Araya-Durán, Ingrid; Reyes, Rodrigo; Vidaurre, Soledad; Romero, Valentina; Fuentes, Juan; Céric, Francisco; Velásquez, Luis; González-Nilo, Fernando D; Otero, Carolina


    Poly(amidoamine) dendrimers are the most recognized class of dendrimer. Amino-terminated (PAMAM-NH2) and hydroxyl-terminated (PAMAM-OH) dendrimers of generation 4 are widely used, since they are commercially available. Both have different properties, mainly based on their different overall charges at physiological pH. Currently, an important function of dendrimers as carriers of short single-stranded DNA has been applied. These molecules, known as antisense oligonucleotides (asODNs), are able to inhibit the expression of a target mRNA. Whereas PAMAM-NH2 dendrimers have shown to be able to transfect plasmid DNA, PAMAM-OH dendrimers have not shown the same successful results. However, little is known about their interaction with shorter and more flexible molecules such as asODNs. Due to several initiatives, the use of these neutral dendrimers as a scaffold to introduce other functional groups has been proposed. Because of its low cytotoxicity, it is relevant to understand the molecular phenomena involving these types of dendrimers. In this work, we studied the behavior of an antisense oligonucleotide in presence of both types of dendrimers using molecular dynamics simulations, in order to elucidate if they are able to form stable complexes. In this manner, we demonstrated at atomic level that PAMAM-NH2, unlike PAMAM-OH, could form a well-compacted complex with asODN, albeit PAMAM-OH can also establish stable interactions with the oligonucleotide. The biological activity of asODN in complex with PAMAM-NH2 dendrimer was also shown. Finally, we revealed that in contact with PAMAM-OH, asODN remains outside the cells as TIRF microscopy results showed, due to its poor interaction with this dendrimer and cell membranes.

  10. Mismatch oligonucleotides in human and yeast: guidelines for probe design on tiling microarrays

    Directory of Open Access Journals (Sweden)

    Jee Justin


    Full Text Available Abstract Background Mismatched oligonucleotides are widely used on microarrays to differentiate specific from nonspecific hybridization. While many experiments rely on such oligos, the hybridization behavior of various degrees of mismatch (MM structure has not been extensively studied. Here, we present the results of two large-scale microarray experiments on S. cerevisiae and H. sapiens genomic DNA, to explore MM oligonucleotide behavior with real sample mixtures under tiling-array conditions. Results We examined all possible nucleotide substitutions at the central position of 36-nucleotide probes, and found that nonspecific binding by MM oligos depends upon the individual nucleotide substitutions they incorporate: C→A, C→G and T→A (yielding purine-purine mispairs are most disruptive, whereas A→X were least disruptive. We also quantify a marked GC skew effect: substitutions raising probe GC content exhibit higher intensity (and vice versa. This skew is small in highly-expressed regions (± 0.5% of total intensity range and large (± 2% or more elsewhere. Multiple mismatches per oligo are largely additive in effect: each MM added in a distributed fashion causes an additional 21% intensity drop relative to PM, three-fold more disruptive than adding adjacent mispairs (7% drop per MM. Conclusion We investigate several parameters for oligonucleotide design, including the effects of each central nucleotide substitution on array signal intensity and of multiple MM per oligo. To avoid GC skew, individual substitutions should not alter probe GC content. RNA sample mixture complexity may increase the amount of nonspecific hybridization, magnify GC skew and boost the intensity of MM oligos at all levels.

  11. Development and validation of an oligonucleotide microarray to characterise ectomycorrhizal fungal communities

    Directory of Open Access Journals (Sweden)

    Reich Marlis


    Full Text Available Abstract Background In forest ecosystems, communities of ectomycorrhizal fungi (ECM are influenced by several biotic and abiotic factors. To understand their underlying dynamics, ECM communities have been surveyed with ribosomal DNA-based sequencing methods. However, most identification methods are both time-consuming and limited by the number of samples that can be treated in a realistic time frame. As a result of ongoing implementation, the array technique has gained throughput capacity in terms of the number of samples and the capacity for parallel identification of several species. Thus far, although phylochips (microarrays that are used to detect species have been mostly developed to trace bacterial communities or groups of specific fungi, no phylochip has been developed to carry oligonucleotides for several ectomycorrhizal species that belong to different genera. Results We have constructed a custom ribosomal DNA phylochip to identify ECM fungi. Specific oligonucleotide probes were targeted to the nuclear internal transcribed spacer (ITS regions from 95 fungal species belonging to 21 ECM fungal genera. The phylochip was first validated using PCR amplicons of reference species. Ninety-nine percent of the tested oligonucleotides generated positive hybridisation signals with their corresponding amplicons. Cross-hybridisation was mainly restricted at the genus level, particularly for Cortinarius and Lactarius species. The phylochip was subsequently tested with environmental samples that were composed of ECM fungal DNA from spruce and beech plantation fungal communities. The results were in concordance with the ITS sequencing of morphotypes and the ITS clone library sequencing results that were obtained using the same PCR products. Conclusion For the first time, we developed a custom phylochip that is specific for several ectomycorrhizal fungi. To overcome cross-hybridisation problems, specific filter and evaluation strategies that used spot

  12. Abundance analysis of DAZ white dwarfs

    CERN Document Server

    Kawka, Adela; Dinnbier, Frantisek; Cibulkova, Helena; Nemeth, Peter


    We present an abundance analysis of a sample of 33 hydrogen-rich (DA) white dwarfs. We have used archival high-resolution spectra to measure abundances of calcium, magnesium and iron in a set of 30 objects. In addition, we present preliminary calcium abundances in three new white dwarfs based on low-dispersion spectra. We investigate some abundance ratios (Mg/Ca, Fe/Ca) that may help uncover the composition of the accretion source.

  13. Prickly business: abundance of sea urchins on breakwaters and coral reefs in Dubai. (United States)

    Bauman, Andrew G; Dunshea, Glenn; Feary, David A; Hoey, Andrew S


    Echinometra mathaei is a common echinoid on tropical reefs and where abundant plays an important role in the control of algal communities. Despite high prevalence of E. mathaei on southern Persian/Arabian Gulf reefs, their abundance and distribution is poorly known. Spatial and temporal patterns in population abundance were examined at 12 sites between breakwater and natural reef habitats in Dubai (UAE) every 3 months from 2008 to 2010. Within the breakwater habitat, densities were greatest at shallow wave-exposed sites, and reduced with both decreasing wave-exposure and increasing depth. Interestingly, E. mathaei were significantly more abundant on exposed breakwaters than natural reef sites, presumably due to differences in habitat structure and benthic cover. Population abundances differed seasonally, with peak abundances during summer (July-September) and lower abundances in winter (December-February). Seasonal fluctuations are likely the result of peak annual recruitment pulses coupled with increased fish predation from summer to winter.

  14. Metaproteomics reveals abundant transposase expression in mutualistic endosymbionts

    Energy Technology Data Exchange (ETDEWEB)

    Kleiner, Manuel [Max Planck Institute for Marine Microbiology; Young, Jacque C [ORNL; Shah, Manesh B [ORNL; Verberkmoes, Nathan C [ORNL; Dubilier, Nicole [Max Planck Institute for Marine Microbiology


    Transposases, enzymes that catalyze the movement of mobile genetic elements, are the most abundant genes in nature. While many bacteria encode an abundance of transposases in their genomes, the current paradigm is that transposase gene expression is tightly regulated and generally low due to its severe mutagenic effects. In the current study, we detected the highest number of transposase proteins ever reported in bacteria, in symbionts of the gutless marine worm Olavius algarvensis using metaproteomics. At least 26 different transposases from 12 different families were detected and genomic and proteomic analyses suggest many of these are active. This high expression of transposases indicates that the mechanisms for their tight regulation have been disabled or destroyed. Based on recent studies on other symbionts and pathogens that showed high transposase transcription, we speculate that abundant transposase expression might be common in symbionts and pathogens.

  15. Tuning molecular interactions in lipid-oligonucleotides assemblies via locked nucleic acid (LNA)-based lipids. (United States)

    Patwa, Amit; Salgado, Gilmar; Dole, François; Navailles, Laurence; Barthélémy, Philippe


    Hybrid nucleotide-lipids containing locked nucleic acid (LNA) show enhanced hybridization properties with complementary single strand RNAs compared to DNA lipid analogues. The LNA adenosine lipid features unique binding properties with a high binding affinity for poly-uridine and the entropically driven formation of a stable complex (K(d) ≈ 43 nM). Enhanced hybridization properties of LNA-based lipids should be applicable for the development of oligonucleotide (ON) delivery systems or as small molecule binders to RNA for novel therapeutic strategies.

  16. Information Limited Oligonucleotide Amplification Assay for Affinity-Based, Parallel Detection Studies.

    Directory of Open Access Journals (Sweden)

    Harish Bokkasam

    Full Text Available Molecular communication systems encounter similar constraints as telecommunications. In either case, channel crosstalk at the receiver end will result in information loss that statistical analysis cannot compensate. This is because in any communication channel there is a physical limit to the amount of information that can be transmitted. We present a novel and simple modified end amplification (MEA technique to generate reduced and defined amounts of specific information in form of short fragments from an oligonucleotide source that also contains unrelated and redundant information. Our method can be a valuable tool to investigate information overflow and channel capacity in biomolecular recognition systems.

  17. Recursive construction of perfect DNA molecules and libraries from imperfect oligonucleotides. (United States)

    Linshiz, Gregory; Yehezkel, Tuval Ben; Shapiro, Ehud


    Making faultless complex objects from potentially faulty building blocks is a fundamental challenge in computer engineering, nanotechnology, and synthetic biology. We developed an error-correcting recursive construction procedure that attempts to address this challenge. Making DNA molecules from synthetic oligonucleotides using the procedure described here surpasses existing methods for de novo DNA synthesis in speed, precision, and amenability to automation. It provides for the first time a unified DNA construction platform for combining synthetic and natural DNA fragments, for constructing designer DNA libraries, and for making the faultless long synthetic DNA building blocks needed for de novo genome construction.

  18. Screening for oligonucleotide binding affinity by a convenient fluorescence competition assay. (United States)

    Harrison, J G; Liu, X; Balasubramanian, S


    A competitive homogeneous quenched fluorescence assay system is described for the high throughput screening of DNA conjugates that bind to single-stranded DNA. Fluorescence signal is generated by competitive binding of the sample molecule to a target strand labelled with a quencher probe, which is otherwise hybridised to a complementary strand containing a fluorescent probe. Thus fluorescence generated is related to the affinity of the sample. Competitive analysis of a number of peptide-oligonucleotide conjugates gave data that correlated well with the corresponding UV melting data. The assay will be useful for screening of large numbers of potential single-stranded binding molecules.

  19. Morpholino antisense oligonucleotides targeting intronic repressor Element1 improve phenotype in SMA mouse models


    Osman, Erkan Y.; Miller, Madeline R.; Robbins, Kate L.; Lombardi, Abby M.; Atkinson, Arleigh K.; Brehm, Amanda J.; Lorson, Christian L.


    Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by the loss of Survival Motor Neuron-1 (SMN1). In all SMA patients, a nearly identical copy gene called SMN2 is present, which produces low levels of functional protein owing to an alternative splicing event. To prevent exon-skipping, we have targeted an intronic repressor, Element1 (E1), located upstream of SMN2 exon 7 using Morpholino-based antisense oligonucleotides (E1MO-ASOs). A single intracerebroventricular injection i...

  20. Human genomic library screened with 17-base oligonucleotide probes yields a novel interferon gene.


    Torczynski, R M; Fuke, M; Bollon, A P


    A method is presented that has permitted a human genomic library to be screened for low-copy genes using 17-base synthetic oligonucleotides as probes. Parallel screening with two different 17-base probes permitted the unambiguous identification of clones containing interferon-alpha (IFN-alpha) genes. The isolated human IFN-alpha genes were sequenced, and one appears to be IFN-alpha L; the other is one not previously described, which we have designated IFN-alpha WA. The IFN-alpha WA sequence d...

  1. Synthesis of antisense oligonucleotides containing acyclic alkynyl nucleoside analogs and their biophysical and biological properties. (United States)

    Ogata, Aya; Maeda, Yusuke; Ueno, Yoshihito


    The synthesis of oligonucleotide (ON) analogs, which can be used as antisense molecules, has recently gained much attention. Here, we report the synthesis and properties of an ON analog containing acyclic thymidine and cytidine analogs with a 4-pentyl-1,2-diol instead of the d-ribofuranose moiety. The incorporation of these analogs into the ON improved its nuclease resistance to 3'-exonucleases. Furthermore, it was found that the incorporation of the acyclic thymidine analog into a DNA/RNA duplex accelerates the RNA cleavage of a DNA/RNA duplex by Escherichia coli RNase H.

  2. Oligonucleotide fishing for STAT6: cross-talk between IL-4 and chemokines

    DEFF Research Database (Denmark)

    Eriksen, K W; Nielsen, M; Kaltoft, K;


    , the distance between the binding sites is critical for STAT-DNA binding, i.e. STAT6 binding is decreased at distances above 20 nucleotides between neighbouring binding sites. Using this assay to study cross-talk between IL-4 and chemokines, we provide evidence that MIP-1beta and MIG inhibit IL-4-induced STAT6...... activation, whereas other chemokines and cytokines do not. In conclusion, our data show that oligonucleotide fishing is a supplementary tool for studying cytokine cross-talk at a genomic level....

  3. Effect of antisense oligonucleotides targeting telomerase catalytic subunit on tumor cell proliferationin vitro

    Institute of Scientific and Technical Information of China (English)


    To screen specific antitumor drugs targeting telomerase catalytic subunit (hEST2), 12 different hEST2 antisense oligonucleotides were designed based on hEST2 mRNA second structure and transfected into tumor cell lines by the lipofectin-mediated method. Cell growth activity was evaluated by MTT assay. hEST212 was picked out and its specificity, antitumor tree and continuous effect were analyzed. The results showed that hEST212 had promising antitumor activity in vitro, hEST2 can be used as a pratical target and an antisense drug candidate for cancer.

  4. Optical Properties and In Vitro Biological Studies of Oligonucleotide-Modified Quantum Dots

    Directory of Open Access Journals (Sweden)

    Valérie A. Gérard


    Full Text Available Water-soluble semiconducting nanocrystals or quantum dots (QDs have attracted much interest in recent years due to their tuneable emission and potential applications in photonics and biological imaging. Fluorescence resonance energy transfer (FRET processes are very important for elucidating biochemical mechanisms in vitro, and QDs constitute an excellent substrate for this purpose. In this work, new oligonucleotide-functionalised CdTe-based QDs were prepared, characterised and biologically tested. These QDs demonstrated interesting optical properties as well as remarkable in vitro behaviour and potential for a range of biological applications.

  5. Detection of hepatitis B virus genotypes using oligonucleotide chip among hepatitis B virus carriers in Eastern China

    Institute of Scientific and Technical Information of China (English)

    Xiang-Rong Tang; Ji-Shen Zhang; Hui Zhao; Yu-Hua Gong; Yong-Zhong Wang; Jian-Long Zhao


    AIM: To determine the genotype distribution of hepatitis B virus (HBV) with a newly oligonucleotide chip assay among the HBV carriers in Eastern China.METHODS: An assay using oligonucleotide chip was developed for detection of HBV genotypes in serum samples from HBV DNA-positive patients in Eastern China. This method is based on the principle of reverse hybridization with Cy5-labeled amplicons hybridizing to type-specific oligonucleotide probes that are immobilized on slides. The results of 80 randomly chosen sera were confirmed by direct sequencing.RESULTS: HBV genotype B, C and mixed genotype were detected in 400 serum samples, accounting for8.3% (n = 33), 83.2% (n = 333), and 8.5% (n = 34),respectively. The evaluation of the oligonucleotide assay showed 100% concordance with the amplicon phylogenetic analysis except 9 mixed genotype infections undetected by sequencing.CONCLUSION: The study indicates that HBV genotype C and B prevail in the Eastern China. It is suggested that the oligonucleotide chip is a reliable and convenient tool for the detection of HBV genotyping.

  6. Resolving prokaryotic taxonomy without rRNA: longer oligonucleotide word lengths improve genome and metagenome taxonomic classification.

    Directory of Open Access Journals (Sweden)

    Eric B Alsop

    Full Text Available Oligonucleotide signatures, especially tetranucleotide signatures, have been used as method for homology binning by exploiting an organism's inherent biases towards the use of specific oligonucleotide words. Tetranucleotide signatures have been especially useful in environmental metagenomics samples as many of these samples contain organisms from poorly classified phyla which cannot be easily identified using traditional homology methods, including NCBI BLAST. This study examines oligonucleotide signatures across 1,424 completed genomes from across the tree of life, substantially expanding upon previous work. A comprehensive analysis of mononucleotide through nonanucleotide word lengths suggests that longer word lengths substantially improve the classification of DNA fragments across a range of sizes of relevance to high throughput sequencing. We find that, at present, heptanucleotide signatures represent an optimal balance between prediction accuracy and computational time for resolving taxonomy using both genomic and metagenomic fragments. We directly compare the ability of tetranucleotide and heptanucleotide world lengths (tetranucleotide signatures are the current standard for oligonucleotide word usage analyses for taxonomic binning of metagenome reads. We present evidence that heptanucleotide word lengths consistently provide more taxonomic resolving power, particularly in distinguishing between closely related organisms that are often present in metagenomic samples. This implies that longer oligonucleotide word lengths should replace tetranucleotide signatures for most analyses. Finally, we show that the application of longer word lengths to metagenomic datasets leads to more accurate taxonomic binning of DNA scaffolds and have the potential to substantially improve taxonomic assignment and assembly of metagenomic data.

  7. Planetary nebulae abundances and stellar evolution

    NARCIS (Netherlands)

    Pottasch, S. R.; Bernard-Salas, J.


    A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradi

  8. Planetary nebulae abundances and stellar evolution II

    NARCIS (Netherlands)

    Pottasch, S. R.; Bernard-Salas, J.


    Context. In recent years mid-and far infrared spectra of planetary nebulae have been analysed and lead to more accurate abundances. It may be expected that these better abundances lead to a better understanding of the evolution of these objects. Aims. The observed abundances in planetary nebulae are

  9. How much can we trust high-resolution spectroscopic stellar chemical abundances? (United States)

    Blanco-Cuaresma, S.; Nordlander, T.; Heiter, U.; Jofré, P.; Masseron, T.; Casamiquela, L.; Tabernero, H. M.; Bhat, S. S.; Casey, A. R.; Meléndez, J.; Ramírez, I.


    To study stellar populations, it is common to combine chemical abundances from different spectroscopic surveys/studies where different setups were used. These inhomogeneities can lead us to inaccurate scientific conclusions. In this work, we studied one aspect of the problem: When deriving chemical abundances from high-resolution stellar spectra, what differences originate from the use of different radiative transfer codes?

  10. How much can we trust high-resolution spectroscopic stellar chemical abundances?

    CERN Document Server

    Blanco-Cuaresma, S; Heiter, U; Jofré, P; Masseron, T; Casamiquela, L; Tabernero, H M; Bhat, S S; Casey, A R; Meléndez, J; Ramírez, I


    To study stellar populations, it is common to combine chemical abundances from different spectroscopic surveys/studies where different setups were used. These inhomogeneities can lead us to inaccurate scientific conclusions. In this work, we studied one aspect of the problem: When deriving chemical abundances from high-resolution stellar spectra, what differences originate from the use of different radiative transfer codes?

  11. Urban warming drives insect pest abundance on street trees.

    Directory of Open Access Journals (Sweden)

    Emily K Meineke

    Full Text Available Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.

  12. The oligonucleotide binding (OB-fold domain of KREPA4 is essential for stable incorporation into editosomes.

    Directory of Open Access Journals (Sweden)

    Smriti Kala

    Full Text Available Most mitochondrial mRNAs in trypanosomatid parasites require uridine insertion/deletion RNA editing, a process mediated by guide RNA (gRNA and catalyzed by multi-protein complexes called editosomes. The six oligonucleotide/oligosaccharide binding (OB-fold proteins (KREPA1-A6, are a part of the common core of editosomes. They form a network of interactions among themselves as well as with the insertion and deletion sub-complexes and are essential for the stability of the editosomes. KREPA4 and KREPA6 proteins bind gRNA in vitro and are known to interact directly in yeast two-hybrid analysis. In this study, using several approaches we show a minimal interaction surface of the KREPA4 protein that is required for this interaction. By screening a series of N- and C-terminally truncated KREPA4 fragments, we show that a predicted α-helix of KREPA4 OB-fold is required for its interaction with KREPA6. An antibody against the KREPA4 α-helix or mutations of this region can eliminate association with KREPA6; while a peptide fragment corresponding to the α-helix can independently interact with KREPA6, thereby supporting the identification of KREPA4-KREPA6 interface. We also show that the predicted OB-fold of KREPA4; independent of its interaction with gRNA, is responsible for the stable integration of KREPA4 in the editosomes, and editing complexes co-purified with the tagged OB-fold can catalyze RNA editing. Therefore, we conclude that while KREPA4 interacts with KREPA6 through the α-helix region of its OB-fold, the entire OB-fold is required for its integration in the functional editosome, through additional protein-protein interactions.

  13. Generalized estimators of avian abundance from count survey data

    Directory of Open Access Journals (Sweden)

    Royle, J. A.


    Full Text Available I consider modeling avian abundance from spatially referenced bird count data collected according to common protocols such as capture-recapture, multiple observer, removal sampling and simple point counts. Small sample sizes and large numbers of parameters have motivated many analyses that disregard the spatial indexing of the data, and thus do not provide an adequate treatment of spatial structure. I describe a general framework for modeling spatially replicated data that regards local abundance as a random process, motivated by the view that the set of spatially referenced local populations (at the sample locations constitute a metapopulation. Under this view, attention can be focused on developing a model for the variation in local abundance independent of the sampling protocol being considered. The metapopulation model structure, when combined with the data generating model, define a simple hierarchical model that can be analyzed using conventional methods. The proposed modeling framework is completely general in the sense that broad classes of metapopulation models may be considered, site level covariates on detection and abundance may be considered, and estimates of abundance and related quantities may be obtained for sample locations, groups of locations, unsampled locations. Two brief examples are given, the first involving simple point counts, and the second based on temporary removal counts. Extension of these models to open systems is briefly discussed.

  14. Systematic evaluation and optimization of modification reactions of oligonucleotides with amines and carboxylic acids for the synthesis of DNA-encoded chemical libraries. (United States)

    Franzini, Raphael M; Samain, Florent; Abd Elrahman, Maaly; Mikutis, Gediminas; Nauer, Angela; Zimmermann, Mauro; Scheuermann, Jörg; Hall, Jonathan; Neri, Dario


    DNA-encoded chemical libraries are collections of small molecules, attached to DNA fragments serving as identification barcodes, which can be screened against multiple protein targets, thus facilitating the drug discovery process. The preparation of large DNA-encoded chemical libraries crucially depends on the availability of robust synthetic methods, which enable the efficient conjugation to oligonucleotides of structurally diverse building blocks, sharing a common reactive group. Reactions of DNA derivatives with amines and/or carboxylic acids are particularly attractive for the synthesis of encoded libraries, in view of the very large number of building blocks that are commercially available. However, systematic studies on these reactions in the presence of DNA have not been reported so far. We first investigated conditions for the coupling of primary amines to oligonucleotides, using either a nucleophilic attack on chloroacetamide derivatives or a reductive amination on aldehyde-modified DNA. While both methods could be used for the production of secondary amines, the reductive amination approach was generally associated with higher yields and better purity. In a second endeavor, we optimized conditions for the coupling of a diverse set of 501 carboxylic acids to DNA derivatives, carrying primary and secondary amine functions. The coupling efficiency was generally higher for primary amines, compared to secondary amine substituents, but varied considerably depending on the structure of the acids and on the synthetic methods used. Optimal reaction conditions could be found for certain sets of compounds (with conversions >80%), but multiple reaction schemes are needed when assembling large libraries with highly diverse building blocks. The reactions and experimental conditions presented in this article should facilitate the synthesis of future DNA-encoded chemical libraries, while outlining the synthetic challenges that remain to be overcome.

  15. Identification of single-nucleotide polymorphisms by the oligonucleotide ligation reaction: a DNA biosensor for simultaneous visual detection of both alleles. (United States)

    Toubanaki, Dimitra K; Christopoulos, Theodore K; Ioannou, Penelope C; Flordellis, Christodoulos S


    Although single nucleotide polymorphisms (SNPs) can be identified by direct hybridization with allele-specific oligonucleotide probes, enzyme-based genotyping methods offer much higher specificity and robustness. Among enzymatic methods, the oligonucleotide ligation reaction (OLR) offers the highest specificity for allele discrimination because two hybridization events are required for ligation. We report the development of a DNA biosensor that offers significant advantages over currently available methods for detection of OLR products: It allows simultaneous visual discrimination of both alleles using a single ligation reaction. Detection is complete within minutes without the need for any specialized instruments. It does not involve multiple cycles of incubation and washing. The dry-reagent format minimizes the pipetting steps. The need for qualified personnel is much lower than current methods. The principle of the assay is as follows: Following PCR amplification, a single OLR is performed using a biotinylated common probe and two allele-specific probes labeled with the haptens digoxigenin and fluorescein. Ligation products corresponding to the normal and mutant allele are double-labeled with biotin and either digoxigenin or fluorescein, respectively. The products are captured by antidigoxigenin or antifluorescein antibodies, or both, that are immobilized at the two test zones of the biosensor and react with antibiotin-functionalized gold nanoparticle reporters. The excess nanoparticles bind to biotinylated albumin that is immobilized at the control zone of the biosensor. The genotype is assigned by the characteristic red lines that appear at the two test zones. The proposed DNA biosensor constitutes a significant step toward point-of-care SNP genotyping.

  16. Improved Genome Editing Efficiency and Flexibility Using Modified Oligonucleotides with TALEN and CRISPR-Cas9 Nucleases. (United States)

    Renaud, Jean-Baptiste; Boix, Charlotte; Charpentier, Marine; De Cian, Anne; Cochennec, Julien; Duvernois-Berthet, Evelyne; Perrouault, Loïc; Tesson, Laurent; Edouard, Joanne; Thinard, Reynald; Cherifi, Yacine; Menoret, Séverine; Fontanière, Sandra; de Crozé, Noémie; Fraichard, Alexandre; Sohm, Frédéric; Anegon, Ignacio; Concordet, Jean-Paul; Giovannangeli, Carine


    Genome editing has now been reported in many systems using TALEN and CRISPR-Cas9 nucleases. Precise mutations can be introduced during homology-directed repair with donor DNA carrying the wanted sequence edit, but efficiency is usually lower than for gene knockout and optimal strategies have not been extensively investigated. Here, we show that using phosphorothioate-modified oligonucleotides strongly enhances genome editing efficiency of single-stranded oligonucleotide donors in cultured cells. In addition, it provides better design flexibility, allowing insertions more than 100 bp long. Despite previous reports of phosphorothioate-modified oligonucleotide toxicity, clones of edited cells are readily isolated and targeted sequence insertions are achieved in rats and mice with very high frequency, allowing for homozygous loxP site insertion at the mouse ROSA locus in particular. Finally, when detected, imprecise knockin events exhibit indels that are asymmetrically positioned, consistent with genome editing taking place by two steps of single-strand annealing.

  17. Spectroscopic (UV/VIS, Raman) and Electrophoresis Study of Cytosine-Guanine Oligonucleotide DNA Influenced by Magnetic Field. (United States)

    Banihashemian, Seyedeh Maryam; Periasamy, Vengadesh; Boon Tong, Goh; Abdul Rahman, Saadah


    Studying the effect of a magnetic field on oligonucleotide DNA can provide a novel DNA manipulation technique for potential application in bioengineering and medicine. In this work, the optical and electrochemical response of a 100 bases oligonucleotides DNA, cytosine-guanine (CG100), is investigated via exposure to different magnetic fields (250, 500, 750, and 1000 mT). As a result of the optical response of CG100 to the magnetic field, the ultra-violet-visible spectrum indicated a slight variation in the band gap of CG100 of about 0.3 eV. Raman spectroscopy showed a significant deviation in hydrogen and phosphate bonds' vibration after exposure to the magnetic field. Oligonucleotide DNA mobility was investigated in the external electric field using the gel electrophoresis technique, which revealed a small decrease in the migration of CG100 after exposure to the magnetic field.

  18. Design and application of 60mer oligonucleotide microarray in SARS coronavirus detection

    Institute of Scientific and Technical Information of China (English)


    The 60mer oligonucleotide microarray was designed and applied to detecting of SARS (severe acute respiratory syndrome) coronavirus. Thirty 60mer specific oligos were designed to cover the whole genome of the first submitted coronavirus strain, according to the sequence of TOR2 (GENEBANK Accession: AY274119). These primers were synthesized and printed into a microarray with 12×12 spots. RNAs were extracted from the throat swab and gargling fluid of SARS patients and reverse-transcripted into the double strand cDNAs. The cDNAs were prepared as restricted cDNA fragments by the restriction display (RD) technique and labeled by PCR with the Cy5-universal primer. The labeled samples were then applied to the oligo microarray for hybridization. The diagnostic capability of the microarray was evaluated after the washing and scanning steps. The scanning result showed that samples of SARS patients were hybridized with multiple SARS probes on the microarray, and there is no signal on the negative and blank controls. These results indicate that the genome of SARS coronavirus can be detected in parallel by the 60mer oligonucleotide microarray, which can improve the positive ratio of the diagnosis. The oligo microarray can also be used for monitoring the behavior of the virus genes in different stages of the disease status.

  19. Short Oligonucleotides Aligned in Stretched Humid Matrix: Secondary DNA Structure in Poly(vinyl alcohol) Environment

    KAUST Repository

    Hanczyc, Piotr


    We report that short, synthetic, double- as well as single-stranded DNA can be aligned in stretched humid poly(vinyl alcohol) (PVA) matrix, and the secondary structure (nucleobase orientation) can be characterized with linear dichroism (LD) spectroscopy. Oligonucleotides of lengths varying between 10 (3.4 nm) and 60 bases (20.4 nm) were investigated with respect to structural properties in the gel-like polymer environment. The DNA conformation as a function of relative humidity reveals a strong dependence of helical structure of DNA on PVA hydration level, results of relevance for nanotechnical studies of DNA-based supramolecular systems. Also, the PVA gel could provide possibilities to test models for nucleic acid interactions and distribution in cell contexts, including structural stability of genetic material in the cell and PVA-packaging for gene delivery. A method by which duplex oligonucleotides, with sequences designed to provide specific binding sites, become amenable to polarized-light spectroscopy opens up new possibilities for studying structure in DNA complexes with small adduct molecules as well as proteins. © 2012 American Chemical Society.

  20. Hammerhead ribozyme activity and oligonucleotide duplex stability in mixed solutions of water and organic compounds

    Directory of Open Access Journals (Sweden)

    Shu-ichi Nakano


    Full Text Available Nucleic acids are useful for biomedical targeting and sensing applications in which the molecular environment is different from that of a dilute aqueous solution. In this study, the influence of various types of mixed solutions of water and water-soluble organic compounds on RNA was investigated by measuring the catalytic activity of the hammerhead ribozyme and the thermodynamic stability of an oligonucleotide duplex. The compounds with a net neutral charge, such as poly(ethylene glycol, small primary alcohols, amide compounds, and aprotic solvent molecules, added at high concentrations changed the ribozyme-catalyzed RNA cleavage rate, with the magnitude of the effect dependent on the NaCl concentration. These compounds also changed the thermodynamic stability of RNA base pairs of an oligonucleotide duplex and its dependence on the NaCl concentration. Specific interactions with RNA molecules and reduced water activity could account for the inhibiting effects on the ribozyme catalysis and destabilizing effects on the duplex stability. The salt concentration dependence data correlated with the dielectric constant, but not with water activity, viscosity, and the size of organic compounds. This observation suggests the significance of the dielectric constant effects on the RNA reactions under molecular crowding conditions created by organic compounds.

  1. A factorial analysis of silanization conditions for the immobilization of oligonucleotides on glass surfaces. (United States)

    Halliwell, C M; Cass, A E


    The modification of glass surfaces with (3-mercaptopropyl)trimethoxysilane and the application of this to DNA chip technology are described. A range of factors influencing the silanization method, and hence the number of surface-bound, chemically active thiol groups, were investigated using a design of experiment approach based on analysis of variance. The number of thiol groups introduced on glass substrates were measured directly using a specific radiolabel, [14C]cysteamine hydrochloride. For liquid-phase silanization, the number of surface-bound thiol groups was found to be dependent on both postsilanization thermal curing and silanization time and relatively independent of silane concentration, reaction temperature, and sample pretreatment. Depending on the conditions used in liquid-phase silanization, (1.3-9.0) x 10(12) thiol groups/cm2 on the glass samples were bound. The reliability and repeatability of liquid- and vacuum-phase silanization were also investigated. Eighteen-base oligonucleotide probes were covalently attached to the modified surfaces via a 3'-amino modification on the DNA and subsequent reaction with the cross-linking reagent N-(gamma-maleimidobutyryloxy) succinimide ester (GMBS). The resulting probe levels were determined and found to be stoichiometric with that of the introduced thiol groups. These results demonstrate that silanization of glass surfaces under specific conditions, prior to probe attachment, is of great importance in the development of DNA chips that use the simple concept of the covalent attachment of presynthesized oligonucleotides to silicon oxide surfaces.

  2. Oligonucleotide-mediated gene modification and its promise for animal agriculture. (United States)

    Laible, Götz; Wagner, Stefan; Alderson, Jon


    One of the great aspirations in modern biology is the ability to utilise the expanding knowledge of the genetic basis of phenotypic diversity through the purposeful tailoring of the mammalian genome. A number of technologies are emerging which have the capacity to modify genes in their chromosomal context. Not surprisingly, the major thrust in this area has come from the evaluation of gene therapy applications to correct mutations implicated in human genetic diseases. The recent development of somatic cell nuclear transfer (SCNT) provides access to these technologies for the purposeful modification of livestock animals. The enormous phenotypic variety existent in contemporary livestock animals has in many cases been linked to quantitative trait loci (QTL) and their underlying point mutations, often referred to as single-nucleotide polymorphisms (SNPs). Thus, the ability for the targeted genetic modification of livestock animals constitutes an attractive opportunity for future agricultural applications. In this review, we will summarize attempts and approaches for oligonucleotide-mediated gene modification (OGM) strategies for the site-specific modification of the genome, with an emphasis on chimeric RNA-DNA oligonucleotides (RDOs) and single-stranded oligonucletides (ssODNs). The potential of this approach for the directed genetic improvement of livestock animals is illustrated through examples, outlining the effects of point mutations on important traits, including meat and milk production, reproductive performance, disease resistance and superior models of human diseases. Current technological hurdles and potential strategies that might remove these barriers in the future are discussed.

  3. Changes in the end-to-end distance distribution in an oligonucleotide following hybridization (United States)

    Parkhurst, Lawrence J.; Parkhurst, Kay M.


    A 16-mer deoxy oligonucleotide was labeled at the 5' end with x- rhodamine and at the 3' end with fluorescein. The fluorescence lifetime of the donor, fluorescein, under conditions for resonance energy transfer, was studied using the SLM 4850 multiharmonic frequency phase fluorometer in order to obtain information on the end-to-end distance distribution P(R) in the oligomer. When this doubly labeled oligonucleotide was hybridized to its 16-mer complement, the fluorescein fluorescence decay could be very well described by a P(R) that was a symmetric shifted Gaussian with center at 68.4 angstrom and (sigma) equals6.4 angstrom. Simulations suggested that part of the width might be attributable to a distribution in (kappa) 2. In the single- stranded labeled oligomer, there was enhanced energy transfer from the fluorescein to the rhodamine and the best fitting symmetrical shifted Gaussian representation of P(R) was centered at 53.8 angstrom with (kappa) equals6.9 angstrom. There was significant lack of fit with this model, however. A model independent procedure was developed for extracting P(R) as a sum of weighted Hermite polynomials. This procedure gave a P(R) with a large negative region at R<20 angstrom, suggesting that rotational averaging for (kappa) 2 was not quite complete prior to significant decay of the donor excited state.

  4. Genetic spell-checking: gene editing using single-stranded DNA oligonucleotides. (United States)

    Rivera-Torres, Natalia; Kmiec, Eric B


    Single-stranded oligonucleotides (ssODNs) can be used to direct the exchange of a single nucleotide or the repair of a single base within the coding region of a gene in a process that is known, generically, as gene editing. These molecules are composed of either all DNA residues or a mixture of RNA and DNA bases and utilize inherent metabolic functions to execute the genetic alteration within the context of a chromosome. The mechanism of action of gene editing is now being elucidated as well as an understanding of its regulatory circuitry, work that has been particularly important in establishing a foundation for designing effective gene editing strategies in plants. Double-strand DNA breakage and the activation of the DNA damage response pathway play key roles in determining the frequency with which gene editing activity takes place. Cellular regulators respond to such damage and their action impacts the success or failure of a particular nucleotide exchange reaction. A consequence of such activation is the natural slowing of replication fork progression, which naturally creates a more open chromatin configuration, thereby increasing access of the oligonucleotide to the DNA template. Herein, how critical reaction parameters influence the effectiveness of gene editing is discussed. Functional interrelationships between DNA damage, the activation of DNA response pathways and the stalling of replication forks are presented in detail as potential targets for increasing the frequency of gene editing by ssODNs in plants and plant cells.

  5. In vivo correction of a Menkes disease model using antisense oligonucleotides. (United States)

    Madsen, Erik C; Morcos, Paul A; Mendelsohn, Bryce A; Gitlin, Jonathan D


    Although the molecular basis of many inherited metabolic diseases has been defined, the availability of effective therapies in such disorders remains problematic. Menkes disease is a fatal neurodegenerative disorder due to loss-of-function mutations in the ATP7A gene encoding a copper-transporting P-type Atpase. To develop therapeutic approaches in affected patients, we have identified a zebrafish model of Menkes disease termed calamity that results from splicing defects in the zebrafish orthologue of the ATP7A gene. Embryonic-recessive lethal mutants have impaired copper homeostasis that results in absent melanin pigmentation, impaired notochord formation, and hindbrain neurodegeneration. In this current study, we have attempted to rescue these striking phenotypic alterations by using a series of antisense morpholino oligonucleotides directed against the splice-site junctions of two mutant calamity alleles. Our findings reveal a robust and complete correction of the copper-deficient defects of calamity in association with the generation of the WT Menkes protein in all rescued mutants. Interestingly, a quantitative analysis of atp7a-specific transcripts suggests that competitive translational regulation may account for the synthesis of WT protein in these embryos. This in vivo correction of Menkes disease through the rescue of aberrant splicing may provide therapeutic options in this fatal disease and illustrates the potential for zebrafish models of human genetic disease in the development of treatments based on the principles of interactions of synthetic oligonucleotide analogues with mRNA.

  6. Optimizing RNA/ENA chimeric antisense oligonucleotides using in vitro splicing. (United States)

    Takeshima, Yasuhiro; Yagi, Mariko; Matsuo, Masafumi


    A molecular therapy for Duchenne muscular dystrophy (DMD) that converts dystrophin mRNA from out-of-frame to in-frame transcripts by inducing exon skipping with antisense oligonucleotides (AOs) is now approaching clinical application. To exploit the broad therapeutic applicability of exon skipping therapy, it is necessary to identify AOs that are able to induce efficient and specific exon skipping. To optimize AOs, we have established an in vitro splicing system using cultured DMD myocytes. Here, we describe the process of identifying the best AO.Cultured DMD myocytes are established from a biopsy sample and the target exon is chosen. A series of AOs are designed to cover the whole target exon sequence. As AOs, we use 15-20-mer chimeric oligonucleotides consisting of 2'-O-methyl RNA and modified nucleic acid (2'-O, 4'-C-ethylene-bridged nucleic acid). Each AO is transfected individually into cultured DMD myocytes, and the resulting mRNA is analyzed by reverse transcription-PCR. The ability of each AO to induce exon skipping is examined by comparing the amount of cDNA with and without exon skipping. If necessary, having roughly localized the target region, another set of AOs are designed and the exon skipping abilities of the new AOs are examined. Finally, one AO is determined as the best for the molecular therapy.Our simple and reliable methods using an in vitro splicing system have enabled us to identify optimized AOs against many exons of the DMD gene.

  7. Reliable Assessment and Quantification of the Fluorescence-Labeled Antisense Oligonucleotides In Vivo

    Directory of Open Access Journals (Sweden)

    Maria Chiara Munisso


    Full Text Available The availability of fluorescent dyes and the advances in the optical systems for in vivo imaging have stimulated an increasing interest in developing new methodologies to study and quantify the biodistribution of labeled agents. However, despite these great achievements, we are facing significant challenges in determining if the observed fluorescence does correspond to the quantity of the dye in the tissues. In fact, although the far-red and near-infrared lights can propagate through several centimetres of tissue, they diffuse within a few millimetres as consequence of the elastic scattering of photons. In addition, when dye-labeled oligonucleotides form stable complex with cationic carriers, a large change in the fluorescence intensity of the dye is observed. Therefore, the measured fluorescence intensity is altered by the tissue heterogeneity and by the fluctuation of dye intensity. Hence, in this study a quantification strategy for fluorescence-labeled oligonucleotides was developed to solve these disadvantageous effects. Our results proved that upon efficient homogenization and dilution with chaotropic agents, such as guanidinium thiocyanate, it is possible to achieve a complete fluorescence intensity recovery. Furthermore, we demonstrated that this method has the advantage of good sensitivity and reproducibility, as well as easy handling of the tissue samples.

  8. Rapid identification of allergenic and pathogenic molds in environmental air by an oligonucleotide array

    Directory of Open Access Journals (Sweden)

    Shiu Lin-Yi


    Full Text Available Abstract Background Airborne fungi play an important role in causing allergy and infections in susceptible people. Identification of these fungi, based on morphological characteristics, is time-consuming, expertise-demanding, and could be inaccurate. Methods We developed an oligonucleotide array that could accurately identify 21 important airborne fungi (13 genera that may cause adverse health problems. The method consisted of PCR amplification of the internal transcribed spacer (ITS regions, hybridization of the PCR products to a panel of oligonucleotide probes immobilized on a nylon membrane, and detection of the hybridization signals with alkaline phosphatase-conjugated antibodies. Results A collection of 72 target and 66 nontarget reference strains were analyzed by the array. Both the sensitivity and specificity of the array were 100%, and the detection limit was 10 pg of genomic DNA per assay. Furthermore, 70 fungal isolates recovered from air samples were identified by the array and the identification results were confirmed by sequencing of the ITS and D1/D2 domain of the large-subunit RNA gene. The sensitivity and specificity of the array for identification of the air isolates was 100% (26/26 and 97.7% (43/44, respectively. Conclusions Identification of airborne fungi by the array was cheap and accurate. The current array may contribute to decipher the relationship between airborne fungi and adverse health effect.

  9. Antisense oligonucleotide therapy for the treatment of C9ORF72 ALS/FTD diseases. (United States)

    Riboldi, Giulietta; Zanetta, Chiara; Ranieri, Michela; Nizzardo, Monica; Simone, Chiara; Magri, Francesca; Bresolin, Nereo; Comi, Giacomo P; Corti, Stefania


    Motor neuron disorders, and particularly amyotrophic lateral sclerosis (ALS), are fatal diseases that are due to the loss of motor neurons in the brain and spinal cord, with progressive paralysis and premature death. It has been recently shown that the most frequent genetic cause of ALS, frontotemporal dementia (FTD), and other neurological diseases is the expansion of a hexanucleotide repeat (GGGGCC) in the non-coding region of the C9ORF72 gene. The pathogenic mechanisms that produce cell death in the presence of this expansion are still unclear. One of the most likely hypotheses seems to be the gain-of-function that is achieved through the production of toxic RNA (able to sequester RNA-binding protein) and/or toxic proteins. In recent works, different authors have reported that antisense oligonucleotides complementary to the C9ORF72 RNA transcript sequence were able to significantly reduce RNA foci generated by the expanded RNA, in affected cells. Here, we summarize the recent findings that support the idea that the buildup of "toxic" RNA containing the GGGGCC repeat contributes to the death of motor neurons in ALS and also suggest that the use of antisense oligonucleotides targeting this transcript is a promising strategy for treating ALS/frontotemporal lobe dementia (FTLD) patients with the C9ORF72 repeat expansion. These data are particularly important, given the state of the art antisense technology, and they allow researchers to believe that a clinical application of these discoveries will be possible soon.

  10. Oligonucleotide-Mediated Genome Editing Provides Precision and Function to Engineered Nucleases and Antibiotics in Plants. (United States)

    Sauer, Noel J; Narváez-Vásquez, Javier; Mozoruk, Jerry; Miller, Ryan B; Warburg, Zachary J; Woodward, Melody J; Mihiret, Yohannes A; Lincoln, Tracey A; Segami, Rosa E; Sanders, Steven L; Walker, Keith A; Beetham, Peter R; Schöpke, Christian R; Gocal, Greg F W


    Here, we report a form of oligonucleotide-directed mutagenesis for precision genome editing in plants that uses single-stranded oligonucleotides (ssODNs) to precisely and efficiently generate genome edits at DNA strand lesions made by DNA double strand break reagents. Employing a transgene model in Arabidopsis (Arabidopsis thaliana), we obtained a high frequency of precise targeted genome edits when ssODNs were introduced into protoplasts that were pretreated with the glycopeptide antibiotic phleomycin, a nonspecific DNA double strand breaker. Simultaneous delivery of ssODN and a site-specific DNA double strand breaker, either transcription activator-like effector nucleases (TALENs) or clustered, regularly interspaced, short palindromic repeats (CRISPR/Cas9), resulted in a much greater targeted genome-editing frequency compared with treatment with DNA double strand-breaking reagents alone. Using this site-specific approach, we applied the combination of ssODN and CRISPR/Cas9 to develop an herbicide tolerance trait in flax (Linum usitatissimum) by precisely editing the 5'-ENOLPYRUVYLSHIKIMATE-3-PHOSPHATE SYNTHASE (EPSPS) genes. EPSPS edits occurred at sufficient frequency that we could regenerate whole plants from edited protoplasts without employing selection. These plants were subsequently determined to be tolerant to the herbicide glyphosate in greenhouse spray tests. Progeny (C1) of these plants showed the expected Mendelian segregation of EPSPS edits. Our findings show the enormous potential of using a genome-editing platform for precise, reliable trait development in crop plants.

  11. Lipid-Albumin Nanoparticles (LAN) for Therapeutic Delivery of Antisense Oligonucleotide against HIF-1α. (United States)

    Li, Hong; Quan, Jishan; Zhang, Mengzi; Yung, Bryant C; Cheng, Xinwei; Liu, Yang; Lee, Young B; Ahn, Chang-Ho; Kim, Deog Joong; Lee, Robert J


    Lipid-albumin nanoparticles (LAN) were synthesized for delivery of RX-0047, an antisense oligonucleotide (ASO) against the hypoxia inducible factor-1 alpha (HIF-1α) to solid tumor. These lipid nanoparticles (LNs) incorporated a human serum albumin-pentaethylenehexamine (HSA-PEHA) conjugate, which is cationic and can form electrostatic complexes with negatively charged oligonucleotides. The delivery efficiency of LAN-RX-0047 was investigated in KB cells and a KB murine xenograft model. When KB cells were treated with LAN-RX-0047, significant HIF-1α downregulation and enhanced cellular uptake were observed compared to LN-RX-0047. LN-RX-0047 and LAN-RX-0047 showed similar cytotoxicity against KB cells with IC50 values of 19.3 ± 3.8 and 20.1 ± 4.2 μM, respectively. LAN-RX-0047 was shown to be taken up by the cells via the macropinocytosis and caveolae-mediated endocytosis pathways while LN-RX-0047 was taken up by cells via caveolae-mediated endocytosis. In the KB xenograft tumor model, LAN-RX-0047 exhibited tumor suppressive activity and significantly reduced intratumoral HIF-1α expression compared to LN-RX-0047. Furthermore, LAN-RX-0047 greatly increased survival time of mice bearing KB-1 xenograft tumors at doses of either 3 mg/kg or 16 mg/kg. These results indicated that LAN-RX-0047 is a highly effective vehicle for therapeutic delivery of antisense agents to tumor.

  12. Analysis of gene expression profiles in human systemic lupus erythematosus using oligonucleotide microarray. (United States)

    Han, G-M; Chen, S-L; Shen, N; Ye, S; Bao, C-D; Gu, Y-Y


    Epidemiologic studies suggest a strong genetic component for susceptibility to systemic lupus erythematosus (SLE). To investigate the genetic mechanism of pathogenesis of SLE, we studied the difference in gene expression of peripheral blood cells between 10 SLE patients and 18 healthy controls using oligonucleotide microarray. When gene expression for patients was compared to the mean of normal controls, among the 3002 target genes, 61 genes were identified with greater than a two-fold change difference in expression level. Of these genes, 24 were upregulated and 37 downregulated in at least half of the patients. By the Welch's ANOVA/Welch's t-test, all these 61 genes were significantly different (PTSA-1/Sca-2) may play an important role in the mechanism of SLE pathogenesis. TSA-1 antigens may represent an important alternative pathway for T-cell activation that may be involved in IFN-mediated immunomodulation. Hierarchical clustering showed that patient samples were clearly separated from controls based on their gene expression profile. These results demonstrate that high-density oligonucleotide microarray has the potential to explore the mechanism of pathogenesis of systemic lupus erythematosus.

  13. Clinical expert panel on monitoring potential lung toxicity of inhaled oligonucleotides: consensus points and recommendations. (United States)

    Alton, Eric W; Boushey, Homer A; Garn, Holger; Green, Francis H; Hodges, Michael; Martin, Richard J; Murdoch, Robert D; Renz, Harald; Shrewsbury, Stephen B; Seguin, Rosanne; Johnson, Graham; Parry, Joel D; Tepper, Jeff; Renzi, Paolo; Cavagnaro, Joy; Ferrari, Nicolay


    Oligonucleotides (ONs) are an emerging class of drugs being developed for the treatment of a wide variety of diseases including the treatment of respiratory diseases by the inhalation route. As a class, their toxicity on human lungs has not been fully characterized, and predictive toxicity biomarkers have not been identified. To that end, identification of sensitive methods and biomarkers that can detect toxicity in humans before any long term and/or irreversible side effects occur would be helpful. In light of the public's greater interests, the Inhalation Subcommittee of the Oligonucleotide Safety Working Group (OSWG) held expert panel discussions focusing on the potential toxicity of inhaled ONs and assessing the strengths and weaknesses of different monitoring techniques for use during the clinical evaluation of inhaled ON candidates. This white paper summarizes the key discussions and captures the panelists' perspectives and recommendations which, we propose, could be used as a framework to guide both industry and regulatory scientists in future clinical research to characterize and monitor the short and long term lung response to inhaled ONs.

  14. Origin of Cosmic Chemical Abundances

    CERN Document Server

    Maio, Umberto


    Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e$^-$, H, H$^+$, H$^-$, He, He$^+$, He$^{++}$, D, D$^+$, H$_2$, H$_2^+$, HD, HeH$^+$), gas cooling, star formation and production of heavy elements (C, N, O, Ne, Mg, Si, S, Ca, Fe, etc.) from stars covering a range of mass and metallicity are used to explore the origin of several chemical abundance patterns and to study both the metal and molecular content during simulated galaxy assembly. The resulting trends show a remarkable similarity to up-to-date observations of the most metal-poor damped Lyman-$\\alpha$ absorbers at redshift $z\\gtrsim 2$. These exhibit a transient nature and represent collapsing gaseous structures captured while cooling is becoming effective in lowering the temperature below $\\sim 10^4\\,\\rm K$, before they are disrupted by episodes of star formation or tidal effects. Our theoretical results agree with the available data for typical elemental ratios, such as [C/O], [Si/Fe], [O/Fe], [Si/O], [Fe/H], [O/...

  15. Pharmacokinetics on a microscale: visualizing Cy5-labeled oligonucleotide release from poly(n-butylcyanoacrylate nanocapsules in cells

    Directory of Open Access Journals (Sweden)

    Tomcin S


    Full Text Available Stephanie Tomcin,1 Grit Baier,1 Katharina Landfester,1 Volker Mailänder1,21Max Planck Institute for Polymer Research, 2University Medical Center of the Johannes Gutenberg University, III Medical Clinic, Mainz, GermanyAbstract: For successful design of a nanoparticulate drug delivery system, the fate of the carrier and cargo need to be followed. In this work, we fluorescently labeled poly(n-butylcyanoacrylate (PBCA nanocapsules as a shell and separately an oligonucleotide (20 mer as a payload. The nanocapsules were formed by interfacial anionic polymerization on aqueous droplets generated by an inverse miniemulsion process. After uptake, the PBCA capsules were shown to be round-shaped, endosomal structures and the payload was successfully released. Cy5-labeled oligonucleotides accumulated at the mitochondrial membrane due to a combination of the high mitochondrial membrane potential and the specific molecular structure of Cy5. The specificity of this accumulation at the mitochondria was shown as the uncoupler dinitrophenol rapidly diminished the accumulation of the Cy5-labeled oligonucleotide. Importantly, a fluorescence resonance energy transfer investigation showed that the dye-labeled cargo (Cy3/Cy5-labeled oligonucleotides reached its target site without degradation during escape from an endosomal compartment to the cytoplasm. The time course of accumulation of fluorescent signals at the mitochondria was determined by evaluating the colocalization of Cy5-labeled oligonucleotides and mitochondrial markers for up to 48 hours. As oligonucleotides are an ideal model system for small interfering RNA PBCA nanocapsules demonstrate to be a versatile delivery platform for small interfering RNA to treat a variety of diseases.Keywords: drug delivery, mitochondria, miniemulsion, colocalization

  16. Multiplex detection of bacteria associated with normal microbiota and with bacterial vaginosis in vaginal swabs by use of oligonucleotide-coupled fluorescent microspheres. (United States)

    Dumonceaux, Tim J; Schellenberg, John; Goleski, Vanessa; Hill, Janet E; Jaoko, Walter; Kimani, Joshua; Money, Deborah; Ball, T Blake; Plummer, Francis A; Severini, Alberto


    Bacterial vaginosis (BV) is a recurrent condition that is associated with a range of negative outcomes, including the acquisition of human immunodeficiency virus and other sexually transmitted diseases, preterm births, and pelvic inflammatory disease. In contrast to the Lactobacillus-dominated normal vaginal microbiota, BV is characterized by a lack of lactobacilli and an abundance of anaerobic and gram-negative organisms, including Gardnerella vaginalis and Atopobium vaginae. To date, the laboratory diagnosis of BV has relied upon the fulfillment of criteria determined by microscopic observation of Gram-stained vaginal swabs. We describe a molecular-based method for the easy determination of the species profile within the vaginal microbiota based on the amplification of the chaperonin-60 genes of all bacteria present in the swab and hybridization of the amplicon to species-specific oligonucleotide-coupled fluorescent beads that are identified by flow cytometry with a Luminex instrument. We designed a nineplex Luminex array for characterization of the vaginal microbiota and applied it to the analysis of vaginal swabs from individuals from Africa and North America. Using the presence of A. vaginae or G. vaginalis, or both, as the defining criterion for BV, we found that the method was highly specific and sensitive for the diagnosis of BV using microscopy as a gold standard.

  17. A Mutagenesis Assay for Reporter Gene Screening Using Partially Degenerate Oligonucleotides of the Tandems NNT and NNC

    Directory of Open Access Journals (Sweden)

    Huifen Xu


    Full Text Available Not all proteins are tolerable to mutations. Whether a specific protein can be a mutable target is of importance in the biotechnology and pharmaceutical industry. This study reported a novel mutagenesis assay using tandem NNT and NNC oligonucleotides to test the mutability of a candidate gene. These two tandem oligonucleotides avoid the risk of forming nonsense mutations and render flexibility of truncating or expanding the insertion size. As a reporter gene, ZeoR (zeocin resistance gene was confirmed to have a high tolerance for mutagenesis by this new assay.

  18. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)



    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may

  19. Synthesis and evaluation of a fluorine-18 labeled antisense oligonucleotide as a potential PET tracer for NOS mRNA expression

    NARCIS (Netherlands)

    de Vries, EFJ; Vroegh, J; Dijkstra, G; Moshage, H; Elsinga, PH; Jansen, PLM; Vaalburg, W


    Inducible NO synthase (iNOS) is overexpressed in inflammatory bowel diseases. An antisense oligonucleotide with good hybridization properties for iNOS mRNA was selected using RT-PCR. The oligonucleotide was reliably labeled with fluorine-18 using N-(4-[F-18]fluorobenzyl)-2-bromoacetamide. Cellular u

  20. Synthesis and properties of triplex-forming oligonucleotides containing 2'-O-(2-methoxyethyl)-5-(3-aminoprop-1-ynyl)-uridine

    DEFF Research Database (Denmark)

    Lou, Chenguang; Xiao, Qiang; Brennan, Lavinia;


    2'-O-(2-Methoxyethyl)-5-(3-aminoprop-1-ynyl)-uridine phosphoramidite (MEPU) has been synthesized from d-ribose and 5-iodouracil and incorporated into triplex-forming oligonucleotides (TFOs) by automated solid-phase oligonucleotide synthesis. The TFOs gave very high triplex stability with their ta...

  1. Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation. (United States)

    Geib, Jennifer C; Strange, James P; Galenj, Candace


    Recent reports of global declines in pollinator species imply an urgent need to assess the abundance of native pollinators and density-dependent benefits for linked plants. In this study, we investigated (1) pollinator nest distributions and estimated colony abundances, (2) the relationship between abundances of foraging workers and the number of nests they represent, (3) pollinator foraging ranges, and (4) the relationship between pollinator abundance and plant reproduction. We examined these questions in an alpine ecosystem in the Colorado Rocky Mountains, focusing on four alpine bumble bee species (Bombus balteatus, B. flavifrons, B. bifarius, and B. sylvicola), and two host plants that differ in their degrees of pollinator specialization (Trifolium dasyphyllum and T. parryi). Using microsatellites, we found that estimated colony abundances among Bombus species ranged from ~18 to 78 colonies/0.01 km2. The long-tongued species B. balteatus was most common, especially high above treeline, but the subalpine species B. bifarius was unexpectedly abundant for this elevation range. Nests detected among sampled foragers of each species were correlated with the number of foragers caught. Foraging ranges were smaller than expected for all Bombus species, ranging from 25 to 110 m. Fruit set for the specialized plant, Trifolium parryi, was positively related to the abundance of its Bombus pollinator. In contrast, fruit set for the generalized plant, T. dasyphyllum, was related to abundance of all Bombus species. Because forager abundance was related to nest abundance of each Bombus species and was an equally effective predictor of plant fecundity, forager inventories are probably suitable for assessing the health of outcrossing plant populations. However, nest abundance, rather than forager abundance, better reflects demographic and genetic health in populations of eusocial pollinators such as bumble bees. Development of models incorporating the parameters we have measured

  2. Unique palindromic sequences in synthetic oligonucleotides are required to induce IFN [correction of INF] and augment IFN-mediated [correction of INF] natural killer activity. (United States)

    Yamamoto, S; Yamamoto, T; Kataoka, T; Kuramoto, E; Yano, O; Tokunaga, T


    Thirty-mer single-stranded oligonucleotides, with a sequence chosen from the known cDNA encoding the 64-kDa protein named Ag A or the MPB-70 protein of Mycobacterium bovis BCG and the human cellular proteins such as complement component 1 inhibitor and Ig rearranged lambda-chain, were used to dissect the capability to induce IFN and to augment NK cell activity of mouse spleen cells by coincubation in vitro. Three with the hexamer palindromic sequence as GACGTC were active, whereas two kinds of oligonucleotides with no palindrome were inactive. The oligonucleotides containing at least one of the different palindromic sequences showed no activity. When a portion of the sequence of the inactive oligonucleotides was substituted with either palindromic sequence of GACGTC, AGCGCT, or AACGTT, the oligonucleotide acquired the ability to augment NK activity. In contrast, the oligonucleotides substituted with another palindromic sequence such as ACCGGT was without effect. Furthermore, exchange of two neighboring mononucleotides within, but not outside, the active palindromic sequence destroyed the ability of the oligonucleotides to augment NK cell activity. Stimulation of spleen cells with the substituted oligonucleotide, A4a-AAC, induced production of significant amounts of IFN-alpha/beta and small amounts of IFN-gamma. Augmentation of NK activity of the cells by the oligonucleotide was ascribed to IFN-alpha/beta production. These results strongly suggest that the presence of the unique palindromic sequences, such as GACGTC, AGCGCT, and AACGTT, but not ACCGGT, is essential for the immunostimulatory activity of oligonucleotides.

  3. Common Tests for Arrhythmia (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Common Tests for Arrhythmia Updated:Dec 21,2016 Several tests can help ... View an animation of arrhythmia . Common Tests for Arrhythmia Holter monitor (continuous ambulatory electrocardiographic monitor) Suspected arrhythmias ...

  4. Commonly Abused Drugs Charts (United States)

    ... Common Forms Common Ways Taken DEA Schedule Juice, Gym Candy, Pumpers, Roids Nandrolone (Oxandrin ® ), oxandrolone (Anadrol ® ), oxymetholone ( ... swings; tiredness; restlessness; loss of appetite; insomnia; lowered sex drive; depression, sometimes leading to suicide attempts. Treatment ...

  5. Finding Common Ground with the Common Core (United States)

    Moisan, Heidi


    This article examines the journey of museum educators at the Chicago History Museum in understanding the Common Core State Standards and implementing them in our work with the school audience. The process raised questions about our teaching philosophy and our responsibility to our audience. Working with colleagues inside and outside of our…

  6. Development of a general methodology for labelling peptide-morpholino oligonucleotide conjugates using alkyne-azide click chemistry. (United States)

    Shabanpoor, Fazel; Gait, Michael J


    We describe a general methodology for fluorescent labelling of peptide conjugates of phosphorodiamidate morpholino oligonucleotides (PMOs) by alkyne functionalization of peptides, subsequent conjugation to PMOs and labelling with a fluorescent compound (Cy5-azide). Two peptide-PMO (PPMO) examples are shown. No detrimental effect of such labelled PMOs was seen in a biological assay.

  7. Massive and selective delivery of lipid-coated cationic lipoplexes of oligonucleotides targeted in vivo to hepatic endothelial cells

    NARCIS (Netherlands)

    Bartsch, M; Weeke-Klimp, AH; Meijer, DKF; Scherphof, GL; Kamps, JAAM


    Purpose. Previously we reported on massive uptake of liposomes surface-modified with negatively charged aconitylated albumin (Aco-HSA) by liver sinusoidal endothelial cells (EC) in vivo. In the present work we applied this principle for the in vivo delivery of antisense oligonucleotides (ODN) to the

  8. Environment-responsive fluorescent nucleoside analogue probe for studying oligonucleotide dynamics in a model cell-like compartment. (United States)

    Pawar, Maroti G; Srivatsan, Seergazhi G


    The majority of fluorescent nucleoside analogue probes that have been used in the in vitro study of nucleic acids are not suitable for cell-based biophysical assays because they exhibit excitation maxima in the UV region and low quantum yields within oligonucleotides. Therefore, we propose that the photophysical characterization of oligonucleotides labeled with a fluorescent nucleoside analogue in reverse micelles (RM), which are good biological membrane models and UV-transparent, could provide an alternative approach to studying the properties of nucleic acids in a cell-like confined environment. In this context, we describe the photophysical properties of an environment-sensitive fluorescent uridine analogue (1), based on the 5-(benzo[b]thiophen-2-yl)pyrimidine core, in micelles and RM. The emissive nucleoside, which is polarity- and viscosity-sensitive, reports the environment of the surfactant assemblies via changes in its fluorescence properties. The nucleoside analogue, incorporated into an RNA oligonucleotide and hybridized to its complementary DNA and RNA oligonucleotides, exhibits a significantly higher fluorescence intensity, lifetime, and anisotropy in RM than in aqueous buffer, which is consistent with the environment of RM. Collectively, our results demonstrate that nucleoside 1 could be utilized as a fluorescent label to study the function of nucleic acids in a model cellular milieu.

  9. Peptide-oligonucleotide conjugates as nanoscale building blocks for assembly of an artificial three-helix protein mimic

    DEFF Research Database (Denmark)

    Lou, Chenguang; Martos-Maldonado, Manuel C.; Madsen, Charlotte Stahl;


    formation have never been realized for de novo protein design. Here, we show the applicability of peptide-oligonucleotide conjugates for self-assembly of higher-ordered protein-like structures. The resulting nano-assemblies were characterized by ultraviolet-melting, gel electrophoresis, circular dichroism...

  10. Group-specific 16S rRNA-targeted oligonucleotide probes to identify thermophilic bacteria in marine hydrothermal vents

    NARCIS (Netherlands)

    Harmsen, HJM; Prieur, D; Jeanthon, C


    Four 16S rRNA-targeted oligonucleotide probes were designed for the detection of thermophilic members of the domain Bacteria known to thrive in marine hydrothermal systems, We developed and characterized probes encompassing most of the thermophilic members of the genus Bacillus, most species of the

  11. Development of bis-locked nucleic acid (bisLNA) oligonucleotides for efficient invasion of supercoiled duplex DNA

    DEFF Research Database (Denmark)

    Moreno, Pedro M D; Geny, Sylvain; Pabon, Y Vladimir;


    In spite of the many developments in synthetic oligonucleotide (ON) chemistry and design, invasion into double-stranded DNA (DSI) under physiological salt and pH conditions remains a challenge. In this work, we provide a new ON tool based on locked nucleic acids (LNAs), designed for strand invasi...

  12. A statistical multiprobe model for analyzing cis and trans genes in genetical genomics experiments with short-oligonucleotide arrays

    NARCIS (Netherlands)

    Alberts, Rudi; Terpstra, Peter; Bystrykh, Leonid V.; Haan, Gerald de; Jansen, Ritsert C.


    Short-oligonucleotide arrays typically contain multiple probes per gene. In genetical genomics applications a statistical model for the individual probe signals can help in separating ‘‘true’’ differential mRNA expression from ‘‘ghost’’ effects caused by polymorphisms, misdesigned probes, and batch

  13. Rapid and specific detection of Lassa virus by reverse transcription-PCR coupled with oligonucleotide array hybridization. (United States)

    Olschläger, Stephan; Günther, Stephan


    To facilitate sequence-specific detection of DNA amplified in a diagnostic reverse transcription (RT)-PCR for Lassa virus, we developed an array featuring 47 oligonucleotide probes for post-PCR hybridization of the amplicons. The array procedure may be performed with low-tech equipment and does not take longer than agarose gel detection.

  14. Development of mercury (II) ion biosensors based on mercury-specific oligonucleotide probes. (United States)

    Li, Lanying; Wen, Yanli; Xu, Li; Xu, Qin; Song, Shiping; Zuo, Xiaolei; Yan, Juan; Zhang, Weijia; Liu, Gang


    Mercury (II) ion (Hg(2+)) contamination can be accumulated along the food chain and cause serious threat to the public health. Plenty of research effort thus has been devoted to the development of fast, sensitive and selective biosensors for monitoring Hg(2+). Thymine was demonstrated to specifically combine with Hg(2+) and form a thymine-Hg(2+)-thymine (T-Hg(2+)-T) structure, with binding constant even higher than T-A Watson-Crick pair in DNA duplex. Recently, various novel Hg(2+) biosensors have been developed based on T-rich Mercury-Specific Oligonucleotide (MSO) probes, and exhibited advanced selectivity and excellent sensitivity for Hg(2+) detection. In this review, we explained recent development of MSO-based Hg(2+) biosensors mainly in 3 groups: fluorescent biosensors, colorimetric biosensors and electrochemical biosensors.

  15. Simultaneous detection and subtyping of porcine endogenous retroviruses proviral DNA using the dual priming oligonucleotide system. (United States)

    Moon, Hyoung Joon; Park, Seong Jun; Kim, Hye Kwon; Ann, Soo Kyung; Rho, Semi; Keum, Hyun Ok; Park, Bong Kyun


    The purpose of this study was to develop a multiplex PCR that can detect porcine endogenous retrovirus (PERV) proviral genes (pol, envA, envB, envC) and porcine mitochondrial DNA, using a dual priming oligonucleotide (DPO) system. The primer specifically detected the PERV proviral genes pol, envA, envB, envC, and porcine mitochondrial DNA only in samples of pig origin. The sensitivity of the primer was demonstrated by simultaneous amplification of all 5 target genes in as little as 10 pg of pig DNA containing PERV proviral genes and mitochondrial DNA. The multiplex PCR, when applied to field samples, simultaneously and successfully amplified PERV proviral genes from liver, blood and hair root samples. Thus, the multiplex PCR developed in the current study using DPO-based primers is a rapid, sensitive and specific assay for the detection and subtyping of PERV proviral genes.

  16. Time-dependent thermocontrol of the hydrophilic and lipophilic properties of DNA oligonucleotide prodrugs. (United States)

    Ausín, Cristina; Grajkowski, Andrzej; Cieślak, Jacek; Gapeev, Alexei; Beaucage, Serge L


    This unit describes the preparation of alkylthioalkylated and formamidoalkylated alcohols, an amidoalkylated alcohol, a hydroxylalkylated phosphoramidate, and their phosphoramidothioate derivatives, all of which have been identified as heat-sensitive thiophosphate-protecting groups in the development of thermolytic immunostimulatory DNA prodrugs. The alcohols are converted to their deoxyribonucleoside phosphoramidite derivatives, which are then used in the preparation of thermosensitive dinucleoside phosphorothioates. The thiophosphate-protecting groups of these dinucleoside phosphorothioates presumably undergo thermolytic cyclodeesterification at elevated temperature under essentially neutral conditions to release the desired phosphorothioate diester function. On the basis of their thermolytic deprotection kinetics, one can identify those thiophosphate-protecting groups that (i) may be useful for thiophosphate protection of CpG motifs of immunostimulatory DNA oligonucleotides (CpG ODNs); (ii) are suitable for protection of phosphodiester functions flanking the CpG motifs; and (iii) offer adequate protection of terminal phosphodiester functions against ubiquitous extracellular and intracellular exonucleases that may be found in biological environments.

  17. An algorithm and program for finding sequence specific oligo-nucleotide probes for species identification

    Directory of Open Access Journals (Sweden)

    Tautz Diethard


    Full Text Available Abstract Background The identification of species or species groups with specific oligo-nucleotides as molecular signatures is becoming increasingly popular for bacterial samples. However, it shows also great promise for other small organisms that are taxonomically difficult to tract. Results We have devised here an algorithm that aims to find the optimal probes for any given set of sequences. The program requires only a crude alignment of these sequences as input and is optimized for performance to deal also with very large datasets. The algorithm is designed such that the position of mismatches in the probes influences the selection and makes provision of single nucleotide outloops. Program implementations are available for Linux and Windows.

  18. Fluoroscence in situ hybridization of chicken intestinal samples with bacterial rRNA targeted oligonucleotide probes

    DEFF Research Database (Denmark)

    Olsen, Katja Nyholm; Francesch, M.; Christensen, Henrik


    The objective was to develop a fast and accurate molecular method for the quantification of the intestinal flora in chickens by rRNA fluorescence in situ hybridization (FISH). Seven weeks old conventionally reared Lohmann hens were used to set up the method. To sample ileal intestinal content......, the distal part from Meckels diverticulum to the ileo-caecal junction was removed. Fixation was performed in ethanol and phosphate buffered saline. After washing by centrifugation, the sample was resuspended in pre-heated hybridization buffer with oligonucleotide probe labelled with Cy3 (10ng/µl). The cells...... were hybridized for 24-72h, centrifuged, washed with pre-heated hybridization buffer, centrifuged and resuspended in Millipore quality water before filtration onto a 0.22 µm black polycarbonate filter. The probes used in this study were, LGC354A, LGC354B, LGC354C, Strc493, Bacto1080, Sal3, Chis150, EUB...

  19. Inhibition of microRNA function by antimiR oligonucleotides

    DEFF Research Database (Denmark)

    Stenvang, Jan; Petri, Andreas; Lindow, Morten


    MicroRNAs (miRNAs) have emerged as important post-transcriptional regulators of gene expression in many developmental and cellular processes. Moreover, there is now ample evidence that perturbations in the levels of individual or entire families of miRNAs are strongly associated...... with the pathogenesis of a wide range of human diseases. Indeed, disease-associated miRNAs represent a new class of targets for the development of miRNA-based therapeutic modalities, which may yield patient benefits unobtainable by other therapeutic approaches. The recent explosion in miRNA research has accelerated...... the development of several computational and experimental approaches for probing miRNA functions in cell culture and in vivo. In this review, we focus on the use of antisense oligonucleotides (antimiRs) in miRNA inhibition for loss-of-function studies. We provide an overview of the currently employed antisense...

  20. Higher order structure of short immunostimulatory oligonucleotides studied by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Dionne C.G., E-mail: [Department of Physics, Norwegian University of Science and Technology, N-7491, Trondheim (Norway); Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Latz, Eicke [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605 (United States); Institute of Innate Immunity, University Hospitals, University of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn (Germany); Espevik, Terje [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Stokke, Bjorn T. [Department of Physics, Norwegian University of Science and Technology, N-7491, Trondheim (Norway)


    Immunostimulatory CpG-DNA activates the innate immune system by binding to Toll-like receptor 9. Structurally different CpG-containing oligonucleotides trigger a different type of immune response while activating the same receptor. We therefore investigated the higher order structure of two different classes of immunostimulatory CpG-DNA. Class A, which contains a partly self-complementary sequence and poly-G ends, forms duplexes and nanoparticles in salt solution, while class B, which does not contain these features and is purely linear, does not form a duplex or nanoparticles. Results obtained here by high-resolution atomic force microscopy of classes A and B CpG-DNA, reflect these differences in secondary structure. Detailed structural analysis of the atomic force microscopy topographs is presented for two different sample preparation methods.

  1. Aminosilane functionalizations of mesoporous oxidized silicon for oligonucleotide synthesis and detection. (United States)

    De Stefano, Luca; Oliviero, Giorgia; Amato, Jussara; Borbone, Nicola; Piccialli, Gennaro; Mayol, Luciano; Rendina, Ivo; Terracciano, Monica; Rea, Ilaria


    Direct solid phase synthesis of peptides and oligonucleotides (ONs) requires high chemical stability of the support material. In this work, we have investigated the passivation ability of porous oxidized silicon multilayered structures by two aminosilane compounds, 3-aminopropyltriethoxysilane and 3-aminopropyldimethylethoxysilane (APDMES), for optical label-free ON biosensor fabrication. We have also studied by spectroscopic reflectometry the hybridization between a 13 bases ON, directly grown on the aminosilane modified porous oxidized silicon by in situ synthesis, and its complementary sequence. Even if the results show that both devices are stable to the chemicals (carbonate/methanol) used, the porous silica structure passivated by APDMES reveals higher functionalization degree due to less steric hindrance of pores.

  2. Improving oligonucleotide fingerprinting of rRNA genes by implementation of polony microarray technology (United States)

    Ruegger, Paul M.; Bent, Elizabeth; Li, Wei; Jeske, Daniel R.; Cui, Xinping; Braun, Jonathan; Jiang, Tao; Borneman, James


    Improvements to oligonucleotide fingerprinting of rRNA genes (OFRG) were obtained by implementing polony microarray technology. OFRG is an array-based method for analyzing microbial community composition. Polonies are discrete clusters of DNA, produced by solid-phase PCR in hydrogels, and derived from individual, spatially isolated DNA molecules. The advantages of a polony-based OFRG method include higher throughput and reductions in the PCR-induced errors and compositional skew inherent in all other PCR-based community composition methods, including high throughput sequencing of rRNA genes. Given the similarities between polony microarrays and certain aspects of sequencing methods such as the Illumina platform, we suggest that if concepts presented in this study were implemented in high throughput sequencing protocols, a reduction of PCR-induced errors and compositional skew may be realized. PMID:22640891

  3. Unsupervised statistical identification of genomic islands using oligonucleotide distributions with application to Vibrio genomes

    Indian Academy of Sciences (India)

    Sanjay Nag; Raghunath Chatterjee; Keya Chaudhuri; Probal Chaudhuri


    Vibrio cholerae, Vibrio vulnificus, Vibrio parahaemolyticus and several other related Vibrio species show distinctly similar two-chromosomal genome organization. However, the modes of pathogenicity are very different among these species, and this is largely attributed to externally acquired genetic elements. We develop some statistical methods to determine these external genetic elements or genomic islands in genomes based on their differential oligonucleotide usage patterns compared to the rest of the genome. Genomic islands identified by these unsupervised statistical methods include integron and pathogenicity islands. After statistical determination of the genomic islands, we investigate their gene contents and their possible association with the pathogenic behaviour of the corresponding Vibrio species. These investigations lead to observations that are of evolutionary and biological significance.

  4. Genetic modification through oligonucleotide-mediated mutagenesis. A GMO regulatory challenge? (United States)

    Breyer, Didier; Herman, Philippe; Brandenburger, Annick; Gheysen, Godelieve; Remaut, Erik; Soumillion, Patrice; Van Doorsselaere, Jan; Custers, René; Pauwels, Katia; Sneyers, Myriam; Reheul, Dirk


    In the European Union, the definition of a GMO is technology-based. This means that a novel organism will be regulated under the GMO regulatory framework only if it has been developed with the use of defined techniques. This approach is now challenged with the emergence of new techniques. In this paper, we describe regulatory and safety issues associated with the use of oligonucleotide-mediated mutagenesis to develop novel organisms. We present scientific arguments for not having organisms developed through this technique fall within the scope of the EU regulation on GMOs. We conclude that any political decision on this issue should be taken on the basis of a broad reflection at EU level, while avoiding discrepancies at international level.

  5. Enzyme-Free Detection of Mutations in Cancer DNA Using Synthetic Oligonucleotide Probes and Fluorescence Microscopy

    DEFF Research Database (Denmark)

    Miotke, Laura; Maity, Arindam; Ji, Hanlee


    microscopy and nucleic acid analogues have been proposed so far. METHODS AND RESULTS: Here we report a novel enzyme-free approach to efficiently detect cancer mutations. This assay includes gene-specific target enrichment followed by annealing to oligonucleotides containing locked nucleic acids (LNAs...... 1000-fold above the potential detection limit. CONCLUSION: Overall, the novel assay we describe could become a new approach to rapid, reliable and enzyme-free diagnostics of cancer or other associated DNA targets. Importantly, stoichiometry of wild type and mutant targets is conserved in our assay...... of methods since they would allow rapid and relatively inexpensive detection of nucleic acids. Modern fluorescence microscopy is having a huge impact on detection of biomolecules at previously unachievable resolution. However, no straightforward methods to detect DNA in a non-enzymatic way using fluorescence...

  6. Phototriggered DNA hairpin formation in a stilbenediether-linked bis(oligonucleotide) conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, F.D.; Liu, X.


    Photochemical switches have found numerous biological applications, but have received only limited application to the control of DNA base pairing processes. The authors report here that a hairpin-forming bis(oligonucleotide) conjugate possessing a stilbenediether linker undergoes reversible trans {leftrightarrow} cis photoisomerization when both the cis and trans conjugates are in the random coil conformation, but undergoes one-way cis {r{underscore}arrow} trans isomerization when both are in hairpin conformations. Thus base-pairing inhibits trans {r{underscore}arrow} cis but not cis {r{underscore}arrow} trans isomerization. Moreover, photoisomerization of the random coil cis conjugate under conditions where the trans conjugate forms a stable hairpin results in phototriggered base pairing. The use of base pairing to effect one-way photoisomerization and of photoisomerization to effect base pairing are without precedent.

  7. Nano-topographic evaluation of highly disordered fractal-like structures of immobilized oligonucleotides using AFM

    Energy Technology Data Exchange (ETDEWEB)

    Sawant, P.D. [BioNanoEngineering Laboratory, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Vic. 4122 (Australia)]. E-mail:; Nicolau, D.V. [BioNanoEngineering Laboratory, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Vic. 4122 (Australia)


    In a recent trend of micro- and nano-array technologies, polymers are gaining preference over traditional substrates such as glass, silicates, etc. as a model biosurface to immobilize biomolecules. In present paper, we compared model polymeric surfaces such as cyclo olefin copolymer (COC) and polycarbonate (PC), with traditional surfaces such as silicone-wafer and mica. We used a 2D fractal dimension method, i.e. the perimeter-area relationship (PAR) to study the immobilization of 26 base pair oligonucleotide primer on surfaces which are imaged by AFM. Results revealed that the efficiency of the vertical immobilization is in the following order: COC > PC > mica > Si-wafer which can be contributed to chemical and nano-topographical heterogeneity. This study is useful for in-depth understanding of fundamental issues such as effects of manufacturing parameters and evaluation of surface nanotopographies for the development of high-density biochips.

  8. Synthetic oligonucleotide antigens modified with locked nucleic acids detect disease specific antibodies (United States)

    Samuelsen, Simone V.; Solov’yov, Ilia A.; Balboni, Imelda M.; Mellins, Elizabeth; Nielsen, Christoffer Tandrup; Heegaard, Niels H. H.; Astakhova, Kira


    New techniques to detect and quantify antibodies to nucleic acids would provide a significant advance over current methods, which often lack specificity. We investigate the potential of novel antigens containing locked nucleic acids (LNAs) as targets for antibodies. Particularly, employing molecular dynamics we predict optimal nucleotide composition for targeting DNA-binding antibodies. As a proof of concept, we address a problem of detecting anti-DNA antibodies that are characteristic of systemic lupus erythematosus, a chronic autoimmune disease with multiple manifestations. We test the best oligonucleotide binders in surface plasmon resonance studies to analyze binding and kinetic aspects of interactions between antigens and target DNA. These DNA and LNA/DNA sequences showed improved binding in enzyme-linked immunosorbent assay using human samples of pediatric lupus patients. Our results suggest that the novel method is a promising tool to create antigens for research and point-of-care monitoring of anti-DNA antibodies. PMID:27775006

  9. Nonenzymatic ligation of an RNA oligonucleotide analyzed by atomic force microscopy. (United States)

    Pino, Samanta; Biasiucci, Mariano; Scardamaglia, Mattia; Gigli, Giuseppe; Betti, Maria Grazia; Mariani, Carlo; Di Mauro, Ernesto


    The products of ligation reaction of a 24 nucleotides long PolyA RNA adsorbed on mica were observed by atomic force microscopy. The occurrence of oligonucleotides at different degrees of polymerization has been quantitatively studied before and after ligation reaction. The microscopy images at the nanoscale show that nonenzymatic ligation of pristine RNA monomers results in the formation of supramolecular aggregates, with prevalence of dimers and tetramers. Analytical conditions were defined allowing the identification, the quantitative evaluation, and their distribution after ligation reaction, also providing an estimate of the degree of hydration of the objects. Such investigation is of particular biological relevance and provides the simplest yet model system for direct investigation of RNA reactions by advanced microscopy.

  10. Synthetic oligonucleotide antigens modified with locked nucleic acids detect disease specific antibodies (United States)

    Samuelsen, Simone V.; Solov'Yov, Ilia A.; Balboni, Imelda M.; Mellins, Elizabeth; Nielsen, Christoffer Tandrup; Heegaard, Niels H. H.; Astakhova, Kira


    New techniques to detect and quantify antibodies to nucleic acids would provide a significant advance over current methods, which often lack specificity. We investigate the potential of novel antigens containing locked nucleic acids (LNAs) as targets for antibodies. Particularly, employing molecular dynamics we predict optimal nucleotide composition for targeting DNA-binding antibodies. As a proof of concept, we address a problem of detecting anti-DNA antibodies that are characteristic of systemic lupus erythematosus, a chronic autoimmune disease with multiple manifestations. We test the best oligonucleotide binders in surface plasmon resonance studies to analyze binding and kinetic aspects of interactions between antigens and target DNA. These DNA and LNA/DNA sequences showed improved binding in enzyme-linked immunosorbent assay using human samples of pediatric lupus patients. Our results suggest that the novel method is a promising tool to create antigens for research and point-of-care monitoring of anti-DNA antibodies.

  11. Genomic analysis by oligonucleotide array Comparative Genomic Hybridization utilizing formalin-fixed, paraffin-embedded tissues. (United States)

    Savage, Stephanie J; Hostetter, Galen


    Formalin fixation has been used to preserve tissues for more than a hundred years, and there are currently more than 300 million archival samples in the United States alone. The application of genomic protocols such as high-density oligonucleotide array Comparative Genomic Hybridization (aCGH) to formalin-fixed, paraffin-embedded (FFPE) tissues, therefore, opens an untapped resource of available tissues for research and facilitates utilization of existing clinical data in a research sample set. However, formalin fixation results in cross-linking of proteins and DNA, typically leading to such a significant degradation of DNA template that little is available for use in molecular applications. Here, we describe a protocol to circumvent formalin fixation artifact by utilizing enzymatic reactions to obtain quality DNA from a wide range of FFPE tissues for successful genome-wide discovery of gene dosage alterations in archival clinical samples.

  12. Microbial distribution and abundance in the digestive system of five shipworm species (Bivalvia: Teredinidae.

    Directory of Open Access Journals (Sweden)

    Meghan A Betcher

    Full Text Available Marine bivalves of the family Teredinidae (shipworms are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes of the gills (ctenidia. These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis. These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose.

  13. Identification of biomarkers for cervical cancer in peripheral blood lymphocytes using oligonucleotide microarrays

    Institute of Scientific and Technical Information of China (English)

    SHENG Jie; ZHANG Wei-yuan


    Background Oligonucleotide microarrays are increasingly being used to identify gene expression profiles that associated with complex genetic diseases. Peripheral lymphocytes communicate with cells and extracellular matrixes in almost all tissues and organs in human body, suggesting that the gene expression profiles in peripheral lymphocytes may reflect the presence of disease in the body. This study aimed to identify molecular biomarkers for cervical cancer in peripheral blood lymphocytes by using oligonucleotide microarrays.Methods Total RNA was extracted from peripheral blood lymphocytes of 24 early stage cervical cancer patients and 18 healthy controls. We used 22K Human Genome microarrays to profile peripheral blood lymphocytes from 4 early stage cervical cancer patients and compared their gene expression profiles with those from 3 healthy controls. Differentially expressed genes would be identified if they had adjusted P values of less than 0.05 and a groupwise average fold change greater than 1.5 or less than 0.67. Then the selected 5 genes were validated in the remaining 20 early stage cervical cancer patients and the 15 healthy controls by using real-time reverse-transcription polymerase chain reaction (RT-PCR).Results Genes identified by the gene selection program expressed differently between the blood samples of the early stage cervical cancer patients and those of the healthy controls. To validate the gene expression data, 5 genes were analyzed by real-time RT-PCR. In three of the 5 identified genes, tenasin-c (TNC), nuceolin (NCL), and enolase 2 (ENO2) showed a significant up-regulation in the blood samples of the early stage cervical cancer patients versus that of the healthy controls.Conclusions The up-regulation of TNC, NCL, and ENO2 in peripheral blood may be used to identify novel blood biomarkers for detecting cervical cancer in a clinically accessible surrogate tissue, and thus to provide a possibility to develop a noninvasive and predictive

  14. Study on Apoptosis-Inducing Effect of XIAP Antisense Oligonucleotides on Glioblastoma Cells in Vitro

    Institute of Scientific and Technical Information of China (English)

    Zhongwei Zhao; Zhengchun Sun; Yunhan Zhang; Ming Zhang; Xudong Ma


    OBJECTIVE To investigate the apoptosis-inducing effect of XIAP antisense oligonucleotides on glioblastoma cells in vitro.METHODS There were 4 groups in our experiment. Group A,as a cell control group, had normal cell culture and no treatment applied. Group B, as a blank control group, had normal cell culture and no liposome control of ASODN. Group C was N-ODN.Group D was the ASODN group. RT-PCR and Western blot assay were conducted to detect the expression of XIAP in all A-172cell groups after treatment with XIAP antisense oligonucleotides (ASODN). MTT assay and flow-cytometry (FCM) detection were used to detect the ability of cell anchoring growth and apoptotic rates of all groups. The processing time was 72 h.RESULTS The expression of XIAP in the A-172 cells was greatly down-regulated, after treated with XIAP-ASODN. Among different concentrations of ASODN, the 300nM was the most optimal one. The down-regulation of XIAP obviously inhibited the succinate dehydrogenase (SDH) activity of the A-172 cells and the increased apoptotic rate of A-172 cells (87.45%) was significantly higher than that of the A-172 in the control groups. There was a statistically significant difference between the treatment and control groups (P < 0.01).CONCLUSION The XIAP-ASODN can effectively regulate the expression of the XIAP down, as a result, inhibit the growth of the glioblastoma cells (A-172) and obviously increase the apoptotic rate of the A-172 cells. The results of the study manifest an overt killing role of XIAP-ASODN to the glioblastoma cells.

  15. The role of helper lipids in lipid nanoparticles (LNPs) designed for oligonucleotide delivery. (United States)

    Cheng, Xinwei; Lee, Robert J


    Lipid nanoparticles (LNPs) have shown promise as delivery vehicles for therapeutic oligonucleotides, including antisense oligos (ONs), siRNA, and microRNA mimics and inhibitors. In addition to a cationic lipid, LNPs are typically composed of helper lipids that contribute to their stability and delivery efficiency. Helper lipids with cone-shape geometry favoring the formation hexagonal II phase, such as dioleoylphosphatidylethanolamine (DOPE), can promote endosomal release of ONs. Meanwhile, cylindrical-shaped lipid phosphatidylcholine can provide greater bilayer stability, which is important for in vivo application of LNPs. Cholesterol is often included as a helper that improves intracellular delivery as well as LNP stability in vivo. Inclusion of a PEGylating lipid can enhance LNP colloidal stability in vitro and circulation time in vivo but may reduce uptake and inhibit endosomal release at the cellular level. This problem can be addressed by choosing reversible PEGylation in which the PEG moiety is gradually released in blood circulation. pH-sensitive anionic helper lipids, such as fatty acids and cholesteryl hemisuccinate (CHEMS), can trigger low-pH-induced changes in LNP surface charge and destabilization that can facilitate endosomal release of ONs. Generally speaking, there is no correlation between LNP activity in vitro and in vivo because of differences in factors limiting the efficiency of delivery. Designing LNPs requires the striking of a proper balance between the need for particle stability, long systemic circulation time, and the need for LNP destabilization inside the target cell to release the oligonucleotide cargo, which requires the proper selection of both the cationic and helper lipids. Customized design and empirical optimization is needed for specific applications.

  16. Comparative analysis of copy number detection by whole-genome BAC and oligonucleotide array CGH

    Directory of Open Access Journals (Sweden)

    Bejjani Bassem A


    Full Text Available Abstract Background Microarray-based comparative genomic hybridization (aCGH is a powerful diagnostic tool for the detection of DNA copy number gains and losses associated with chromosome abnormalities, many of which are below the resolution of conventional chromosome analysis. It has been presumed that whole-genome oligonucleotide (oligo arrays identify more clinically significant copy-number abnormalities than whole-genome bacterial artificial chromosome (BAC arrays, yet this has not been systematically studied in a clinical diagnostic setting. Results To determine the difference in detection rate between similarly designed BAC and oligo arrays, we developed whole-genome BAC and oligonucleotide microarrays and validated them in a side-by-side comparison of 466 consecutive clinical specimens submitted to our laboratory for aCGH. Of the 466 cases studied, 67 (14.3% had a copy-number imbalance of potential clinical significance detectable by the whole-genome BAC array, and 73 (15.6% had a copy-number imbalance of potential clinical significance detectable by the whole-genome oligo array. However, because both platforms identified copy number variants of unclear clinical significance, we designed a systematic method for the interpretation of copy number alterations and tested an additional 3,443 cases by BAC array and 3,096 cases by oligo array. Of those cases tested on the BAC array, 17.6% were found to have a copy-number abnormality of potential clinical significance, whereas the detection rate increased to 22.5% for the cases tested by oligo array. In addition, we validated the oligo array for detection of mosaicism and found that it could routinely detect mosaicism at levels of 30% and greater. Conclusions Although BAC arrays have faster turnaround times, the increased detection rate of oligo arrays makes them attractive for clinical cytogenetic testing.

  17. Oligonucleotide primers for targeted amplification of single-copy nuclear genes in apocritan Hymenoptera.

    Directory of Open Access Journals (Sweden)

    Gerrit Hartig

    Full Text Available BACKGROUND: Published nucleotide sequence data from the mega-diverse insect order Hymenoptera (sawflies, bees, wasps, and ants are taxonomically scattered and still inadequate for reconstructing a well-supported phylogenetic tree for the order. The analysis of comprehensive multiple gene data sets obtained via targeted PCR could provide a cost-effective solution to this problem. However, oligonucleotide primers for PCR amplification of nuclear genes across a wide range of hymenopteran species are still scarce. FINDINGS: Here we present a suite of degenerate oligonucleotide primer pairs for PCR amplification of 154 single-copy nuclear protein-coding genes from Hymenoptera. These primers were inferred from genome sequence data from nine Hymenoptera (seven species of ants, the honeybee, and the parasitoid wasp Nasonia vitripennis. We empirically tested a randomly chosen subset of these primer pairs for amplifying target genes from six Hymenoptera, representing the families Chrysididae, Crabronidae, Gasteruptiidae, Leucospidae, Pompilidae, and Stephanidae. Based on our results, we estimate that these primers are suitable for studying a large number of nuclear genes across a wide range of apocritan Hymenoptera (i.e., all hymenopterans with a wasp-waist and of aculeate Hymenoptera in particular (i.e., apocritan wasps with stingers. CONCLUSIONS: The amplified nucleotide sequences are (a with high probability from single-copy genes, (b easily generated at low financial costs, especially when compared to phylogenomic approaches, (c easily sequenced by means of an additionally provided set of sequencing primers, and (d suitable to address a wide range of phylogenetic questions and to aid rapid species identification via barcoding, as many amplicons contain both exonic and fast-evolving intronic nucleotides.

  18. Abundant Semigroups with a Multiplicative Adequate Transversal

    Institute of Scientific and Technical Information of China (English)

    GUO Xiao Jiang


    The aim of this paper is to investigate abundant semigroups with a multiplicative adequate transversal. Some properties and characterizations for such semigroups are obtained. In particular,we establish the structure of this class of abundant semigroups in terms of left normal bands, right normal bands and adequate semigroups with some simple compatibility conditions. Finally, we apply this structure to some special cases.

  19. Resource Abundance and Resource Dependence in China

    NARCIS (Netherlands)

    Ji, K.; Magnus, J.R.; Wang, W.


    This paper reconsiders the ‘curse of resources’ hypothesis for the case of China, and distinguishes between resource abundance, resource rents, and resource dependence. Resource abundance and resource rents are shown to be approximately equivalent, and their association with resource dependence vari

  20. Diversity and abundance of ammonia-oxidizing

    NARCIS (Netherlands)

    Cardoso, J.F.M.F.; van Bleijswijk, J.D.L.; Witte, H.; van Duyl, F.C.


    We analysed the diversity and abundance of ammonia-oxidizing Archaea (AOA) and Bacteria (AOB) in the shallow warm-water sponge Halisarca caerulea and the deep cold-water sponges Higginsia thielei and Nodastrella nodastrella. The abundance of AOA and AOB was analysed using catalyzed reporter depositi

  1. Immobilization of oligonucleotide probes on silicon surfaces using biotin–streptavidin system examined with microscopic and spectroscopic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Awsiuk, K., E-mail: [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Rysz, J. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Petrou, P. [Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece); Budkowski, A. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Bernasik, A. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, Kraków 30-059 (Poland); Kakabakos, S. [Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece); Marzec, M.M. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, Kraków 30-059 (Poland); Raptis, I. [Institute for Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece)


    To immobilize effectively oligonucleotide probes on SiO{sub 2} modified with (3-aminopropyl)triethoxysilane, four procedures based on streptavidin–biotin system are compared with Atomic Force Microscopy, Angle-Resolved X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. The first approach involves: adsorption of biotinylated Bovine Serum Albumin, blocking free surface sites with BSA, binding of streptavidin and biotinylated oligonucleotide (b-oligo). Final steps are exchanged in the second procedure with immobilization of preformed streptavidin–b-oligo conjugate. The third approach consists of streptavidin adsorption, blocking with BSA and b-oligo binding. Finally, streptavidin–b-oligo conjugate is immobilized directly within the fourth method. Surface coverage with biomolecules, determined from ARXPS, accords with average AFM height, and is anti-correlated with the intensity of Si+ ions. Higher biomolecular coverage was achieved during the last steps of the first (2.45(±0.38) mg/m{sup 2}) and second (1.31(±0.22) mg/m{sup 2}) approach, as compared to lower surface density resulting from the third (0.58(±0.20) mg/m{sup 2}) and fourth (0.41(±0.11) mg/m{sup 2}) method. Phosphorus atomic concentration indicates effectiveness of oligonucleotide immobilization. Secondary ions intensities, characteristic for oligonucleotides, streptavidin, BSA, and proteins, allow additional insight into overlayer composition. These measurements verify the ARXPS results and show the superiority of the first two immobilization approaches in terms of streptavidin and oligonucleotide density achieved onto the surface.

  2. A human in vitro whole blood assay to predict the systemic cytokine response to therapeutic oligonucleotides including siRNA.

    Directory of Open Access Journals (Sweden)

    Christoph Coch

    Full Text Available Therapeutic oligonucleotides including siRNA and immunostimulatory ligands of Toll-like receptors (TLR or RIG-I like helicases (RLH are a promising novel class of drugs. They are in clinical development for a broad spectrum of applications, e.g. as adjuvants in vaccines and for the immunotherapy of cancer. Species-specific immune activation leading to cytokine release is characteristic for therapeutic oligonucleotides either as an unwanted side effect or intended pharmacology. Reliable in vitro tests designed for therapeutic oligonucleotides are therefore urgently needed in order to predict clinical efficacy and to prevent unexpected harmful effects in clinical development. To serve this purpose, we here established a human whole blood assay (WBA that is fast and easy to perform. Its response to synthetic TLR ligands (R848: TLR7/8, LPS: TLR4 was on a comparable threshold to the more time consuming peripheral blood mononuclear cell (PBMC based assay. By contrast, the type I IFN profile provoked by intravenous CpG-DNA (TLR9 ligand in humans in vivo was more precisely replicated in the WBA than in stimulated PBMC. Since Heparin and EDTA, but not Hirudin, displaced oligonucleotides from their delivery agent, only Hirudin qualified as the anticoagulant to be used in the WBA. The Hirudin WBA exhibited a similar capacity as the PBMC assay to distinguish between TLR7-activating and modified non-stimulatory siRNA sequences. RNA-based immunoactivating TLR7/8- and RIG-I-ligands induced substantial amounts of IFN-α in the Hirudin-WBA dependent on delivery agent used. In conclusion, we present a human Hirudin WBA to determine therapeutic oligonucleotide-induced cytokine release during preclinical development that can readily be performed and offers a close reflection of human cytokine response in vivo.

  3. A sensitive method to detect the hepatitis B virus mutations by using solid phase PCR on oligonucleotide array

    Institute of Scientific and Technical Information of China (English)



    A sensitive method based on solid phase PCR on oligonucleotide array was established to detect two point mutations 1896G-A and 1901G-A in hepatitis B virus (HBV) DNA, in which 6 probes including these two point mutations were immobilized on modified glass slides through 5' terminal linker,while the 3' terminal was made to be free. The mutated loci were designed to locate on the last nucleotides of 3' terminal respectively, and the positive control probes lacked the last nucleotide of 3' terminal in comparison with the probes used for detection. Probes fixed on oligonucleotide array were also the solid phase amplification primers. One pair of liquid primers was used to amplify the short template product from whole HBV DNA. Using target DNA as template, the solid primers were extended under the action of Taq DNA polymerase and incorporated with Cy-3dCTP as marker. During the thermal cycling reaction,probes served as solid phase amplification primers and amplification products bound to the oligonucleotide array, which could be visualized by incorporation with fluorescent dyes. After amplification, the oligonucleotide array was washed, performed with laser scanning, and then used for quantitative analysis to obtain the information for mutations. The hybridization results were compared with DNA sequencing. It was demonstrated that in case of sample A, the ratios of fluorescence intensities in wide type and in the muin these two loci. These results correlated to those obtained from DNA sequencing analysis in which the fluorescence intensity ratios in wide type and in the mutated types of 1996G-A and 1901D-A mutations in using solid phase PCR based on oligonucleotide array appears to be a sensitive and promising way to detect mutations with low-density.

  4. Interfacing click chemistry with automated oligonucleotide synthesis for the preparation of fluorescent DNA probes containing internal xanthene and cyanine dyes. (United States)

    Astakhova, I Kira; Wengel, Jesper


    Double-labeled oligonucleotide probes containing fluorophores interacting by energy-transfer mechanisms are essential for modern bioanalysis, molecular diagnostics, and in vivo imaging techniques. Although bright xanthene and cyanine dyes are gaining increased prominence within these fields, little attention has thus far been paid to probes containing these dyes internally attached, a fact which is mainly due to the quite challenging synthesis of such oligonucleotide probes. Herein, by using 2'-O-propargyl uridine phosphoramidite and a series of xanthenes and cyanine azide derivatives, we have for the first time performed solid-phase copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click labeling during the automated phosphoramidite oligonucleotide synthesis followed by postsynthetic click reactions in solution. We demonstrate that our novel strategy is rapid and efficient for the preparation of novel oligonucleotide probes containing internally positioned xanthene and cyanine dye pairs and thus represents a significant step forward for the preparation of advanced fluorescent oligonucleotide probes. Furthermore, we demonstrate that the novel xanthene and cyanine labeled probes display unusual and very promising photophysical properties resulting from energy-transfer interactions between the fluorophores controlled by nucleic acid assembly. Potential benefits of using these novel fluorescent probes within, for example, molecular diagnostics and fluorescence microscopy include: Considerable Stokes shifts (40-110 nm), quenched fluorescence of single-stranded probes accompanied by up to 7.7-fold light-up effect of emission upon target DNA/RNA binding, remarkable sensitivity to single-nucleotide mismatches, generally high fluorescence brightness values (FB up to 26), and hence low limit of target detection values (LOD down to <5 nM).

  5. Spring evolution of Pseudocalanus spp. abundance on Georges Bank based on molecular discrimination of P. moultoni and P. newmani1 (United States)

    Bucklin, Ann; Guarnieri, Maria; McGillicuddy, Dennis J.; Sean Hill, R.

    The planktonic copepod sibling species Pseudocalanus moultoni and P. newmani (Crustacea, Copepoda) are abundant in waters over Georges Bank from late winter until mid-summer and are thought to reproduce throughout this period. The two species cannot be reliably distinguished using morphological characters, but are readily identified and distinguished by simple, rapid, and inexpensive molecular protocols based on sequence variation of mitochondrial DNA (mtDNA). DNA sequence variation of a portion of the mitochondrial cytochrome oxidase I (mtCOI) confirmed the presence of P. moultoni and P. newmani on Georges Bank; the mtCOI sequences were used to design species-specific oligonucleotide primers for use in a competitive multiplexed species-specific polymerase chain reaction (PCR). Species-specific PCR was used to determine the relative abundances of the two species in sub-samples of zooplankton collections from US GLOBEC Georges Bank Study Broadscale Surveys from February to June, 1997. Based on monthly visualizations, we inferred the spring evolution of the two species' distributions and abundances on Georges Bank. Both species' overall abundances increased from February to May or June: maximum abundance of P. moultoni was 38,061 m -2 in surface waters on the crest of Georges Bank in June; maximum abundance of P. newmani was 13,854 m -2 in subsurface waters on the Northeast Peak in April. The Peak in distribution of P. moultoni shifted from Georges Basin in April, to the northern edge of the Bank in May, to the center of the Bank in June. In contrast, P. newmani was more abundant to the south and east of the Bank. Beginning in April, P. newmani occurred on the Bank but was less abundant and less widely-distributed than P. moultoni; P. newmani abundance peaked in May and declined somewhat in June. Females of the species differed in their patterns of distribution and abundance, with P. moultoni always the more abundant species on the crest of the Bank. The spring

  6. Simulated population responses of common carp to commercial exploitation

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Michael J.; Hennen, Matthew J.; Brown, Michael L.


    Common carp Cyprinus carpio is a widespread invasive species that can become highly abundant and impose deleterious ecosystem effects. Thus, aquatic resource managers are interested in controlling common carp populations. Control of invasive common carp populations is difficult, due in part to the inherent uncertainty of how populations respond to exploitation. To understand how common carp populations respond to exploitation, we evaluated common carp population dynamics (recruitment, growth, and mortality) in three natural lakes in eastern South Dakota. Common carp exhibited similar population dynamics across these three systems that were characterized by consistent recruitment (ages 3 to 15 years present), fast growth (K = 0.37 to 0.59), and low mortality (A = 1 to 7%). We then modeled the effects of commercial exploitation on size structure, abundance, and egg production to determine its utility as a management tool to control populations. All three populations responded similarly to exploitation simulations with a 575-mm length restriction, representing commercial gear selectivity. Simulated common carp size structure modestly declined (9 to 37%) in all simulations. Abundance of common carp declined dramatically (28 to 56%) at low levels of exploitation (0 to 20%) but exploitation >40% had little additive effect and populations were only reduced by 49 to 79% despite high exploitation (>90%). Maximum lifetime egg production was reduced from 77 to 89% at a moderate level of exploitation (40%), indicating the potential for recruitment overfishing. Exploitation further reduced common carp size structure, abundance, and egg production when simulations were not size selective. Our results provide insights to how common carp populations may respond to exploitation. Although commercial exploitation may be able to partially control populations, an integrated removal approach that removes all sizes of common carp has a greater chance of controlling population abundance

  7. Bacterioplankton abundance and production and nanozooplankton abundance in Kenyan coastal waters (Western Indian Ocean)

    NARCIS (Netherlands)

    Goosen, N.K.; Van Rijswijk, P.; De Bie, M.J.M.; Peene, J.; Kromkamp, J.C.


    Bacterial abundance, [H-3]thymidine incorporation rate and heterotrophic nanoflagellate abundance were measured in the water column along transects perpendicular to the Kenyan coast (western Indian Ocean) during June-July (SE monsoon) and November-December (intermonsoon) 1992. Bacterial abundance wa

  8. Detecting Abundance Variations in Planetary Nebulae (United States)

    Monteiro, H.; Santos, P. M.; Falceta-Gonçalves, D.


    Empirical methods of investigating chemical abundances are still widely used as a primary tool to study planetary nebulae (PNe) as well as HII regions. In this work we investigate the capacity of the empirical abundance determination methods to recover pre-defined parameters and abundance variations in a realistically modeled planetary nebula. To perform the test we use a threedimensional density structure obtained from a hydrodynamical simulation which is fed through a threedimensional photoionization code. The density structure is an asymetrical and inhomogeneous elongated closed shell. The input parameters used, such as, ionizing source, density, and chemical abundances are typical values of type I PNe. The model emissivities are then projected in the line of sight and emission line maps are generated, which are used to obtain the temperature and density diagnostics. The diagnostics and line emission maps are then used to obtain spatially resolved maps of the abundances. In this work we use the method described above to investigate abundances for two distinct orientations of the density structure. Our results show that for typical signal to noise ratios obtained from long-slit spectroscopy, only large abundance variations can be determined with good precision.

  9. Estimating abundance in the presence of species uncertainty (United States)

    Chambert, Thierry A; Hossack, Blake R.; Fishback, LeeAnn; Davenport, Jon M.


    1.N-mixture models have become a popular method for estimating abundance of free-ranging animals that are not marked or identified individually. These models have been used on count data for single species that can be identified with certainty. However, co-occurring species often look similar during one or more life stages, making it difficult to assign species for all recorded captures. This uncertainty creates problems for estimating species-specific abundance and it can often limit life stages to which we can make inference. 2.We present a new extension of N-mixture models that accounts for species uncertainty. In addition to estimating site-specific abundances and detection probabilities, this model allows estimating probability of correct assignment of species identity. We implement this hierarchical model in a Bayesian framework and provide all code for running the model in BUGS-language programs. 3.We present an application of the model on count data from two sympatric freshwater fishes, the brook stickleback (Culaea inconstans) and the ninespine stickleback (Pungitius pungitius), ad illustrate implementation of covariate effects (habitat characteristics). In addition, we used a simulation study to validate the model and illustrate potential sample size issues. We also compared, for both real and simulated data, estimates provided by our model to those obtained by a simple N-mixture model when captures of unknown species identification were discarded. In the latter case, abundance estimates appeared highly biased and very imprecise, while our new model provided unbiased estimates with higher precision. 4.This extension of the N-mixture model should be useful for a wide variety of studies and taxa, as species uncertainty is a common issue. It should notably help improve investigation of abundance and vital rate characteristics of organisms’ early life stages, which are sometimes more difficult to identify than adults.

  10. The Common Good

    DEFF Research Database (Denmark)

    Feldt, Liv Egholm

    At present voluntary and philanthropic organisations are experiencing significant public attention and academic discussions about their role in society. Central to the debate is on one side the question of how they contribute to “the common good”, and on the other the question of how they can avoid...... and concepts continuously over time have blurred the different sectors and “polluted” contemporary definitions of the “common good”. The analysis shows that “the common good” is not an autonomous concept owned or developed by specific spheres of society. The analysis stresses that historically, “the common...

  11. Lithium Abundance of Metal-poor Stars

    Institute of Scientific and Technical Information of China (English)

    Hua-Wei Zhang; Gang Zhao


    High-resolution, high signal-to-noise ratio spectra have been obtained for 32 metal-poor stars. The equivalent widths of Li λ6708A were measured and the lithium abundances were derived. The average lithium abundance of 21 stars on the lithium plateau is 2.33±0.02 dex. The Lithium plateau exhibits a marginal trend along metallicity, dA(Li)/d[Fe/H] = 0.12±0.06, and no clear trend with the effective temperature. The trend indicates that the abundance of lithium plateau may not be primordial and that a part of the lithium was produced in Galactic Chemical Evolution (GCE).

  12. Study of the primordial lithium abundance

    Institute of Scientific and Technical Information of China (English)


    Lithium isotopes have attracted an intense interest because the abundance of both 6Li and 6Li from big bang nucleosynthesis (BBN) is one of the puzzles in nuclear astrophysics. Many investigations of both astrophysical observation and nucleosynthesis calculation have been carried out to solve the puzzle, but it is not solved yet. Several nuclear reactions involving lithium have been indirectly measured at China Institute of Atomic Energy, Beijing. The Standard BBN (SBBN) network calculations are then performed to investigate the primordial Lithium abundance. The result shows that these nuclear reactions have minimal effect on the SBBN abundances of 6Li and 7Li.

  13. Fish and phytoplankton exhibit contrasting temporal species abundance patterns in a dynamic north temperate lake.

    Directory of Open Access Journals (Sweden)

    Gretchen J A Hansen

    Full Text Available Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of "core" (common occurrence and high abundance and "occasional" (rare occurrence and low abundance species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions.

  14. A novel setup for the determination of absolute cross sections for low-energy electron induced strand breaks in oligonucleotides - The effect of the radiosensitizer 5-fluorouracil* (United States)

    Rackwitz, Jenny; Ranković, Miloš Lj.; Milosavljević, Aleksandar R.; Bald, Ilko


    Low-energy electrons (LEEs) play an important role in DNA radiation damage. Here we present a method to quantify LEE induced strand breakage in well-defined oligonucleotide single strands in terms of absolute cross sections. An LEE irradiation setup covering electron energies 5FU) is studied using an absolute and relative data analysis. We demonstrate an increase in the strand break yields of 5FU containing oligonucleotides by a factor of 1.5 to 1.6 compared with non-modified oligonucleotide sequences when irradiated with 10 eV electrons.

  15. Tragedy of the Commons

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen

    The tittle refers to an article from 1968 by Garrett Hardin, using the metaphore of the common grazing land in villages in old time. These 'Commons' were for free use for people in the commounity to have some sheep grazing. This system was based on a certain social solidarity and ethic...

  16. Chinook Abundance - Linear Features [ds181 (United States)

    California Department of Resources — The dataset 'ds181_Chinook_ln' is a product of the CalFish Adult Salmonid Abundance Database. Data in this shapefile are collected from stream sections or reaches...

  17. Estimating Squirrel Abundance From Live trapping Data (United States)

    US Fish and Wildlife Service, Department of the Interior — A reprint of an article from the Journal of Wildlife Management entitled "Estimating Squirrel Abundance from Live Trapping Data" by Nixon, Edwards and Eberhardt. The...

  18. SWFSC/MMTD: Vaquita Abundance Survey 1997 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1997, the Southwest Fisheries Science Center (SWFSC) conducted a survey designed to estimate the abundance of vaquita, the Gulf of California harbor porpoise...

  19. Iron abundance in the atmosphere of Arcturus

    CERN Document Server

    Sheminova, V A


    Abundance of iron in the atmosphere of Arcturus has been determined from the profiles or regions of the profiles of the weak lines sensitive to iron abundance. The selected lines of Fe I and Fe II were synthesized with the MARCS theoretical models of the atmosphere. From the observed profiles of lines available with a high spectral resolution in the atlas by Hinkle and Wallace (2005), the values of the iron abundance $A = 6.95 \\pm 0.03$ and the radial-tangential macroturbulent velocity $5.6 \\pm 0.2$ km/s were obtained for Arcturus. The same physical quantities were found for the Sun as a star; they are $7.42 \\pm 0.02$ and $3.4 \\pm 0.3$ km/s, respectively. For Arcturus, the iron abundance relative to the solar one was determined with the differential method as [Fe/H] $=-0.48 \\pm 0.02$.

  20. Chemical abundance analysis of 19 barium stars

    CERN Document Server

    Yang, G C; Spite, M; Chen, Y Q; Zhao, G; Zhang, B; Liu, G Q; Liu, Y J; Liu, N; Deng, L C; Spite, F; Hill, V; Zhang, C X


    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures, surface gravities, metallicity and microturbulent velocity) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their light elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn and Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-ca...

  1. Coronae of Stars with Supersolar Elemental Abundances (United States)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.


    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, iota Hor, HR 7291, tau Boo, and alpha Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and tau Boo no FIP effect is present, while iota Hor, HR 7291, and alpha Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  2. Does land abundance explain African institutions?



    The land abundance view of African history uses sparse population to explain pre-colonial land tenure and slavery. I document the geographic forcing variables that predict land rights, slavery, and population density in a cross section of global societies. I discuss whether these correlations support theories of land rights and slavery, including the land abundance view. I show that pre-colonial institutions predict institutional outcomes in Africa in the present, including land transactions,...

  3. An evaluation of oligonucleotide-based therapeutic strategies for polyQ diseases

    Directory of Open Access Journals (Sweden)

    Fiszer Agnieszka


    Full Text Available Abstract Background RNA interference (RNAi and antisense strategies provide experimental therapeutic agents for numerous diseases, including polyglutamine (polyQ disorders caused by CAG repeat expansion. We compared the potential of different oligonucleotide-based strategies for silencing the genes responsible for several polyQ diseases, including Huntington's disease and two spinocerebellar ataxias, type 1 and type 3. The strategies included nonallele-selective gene silencing, gene replacement, allele-selective SNP targeting and CAG repeat targeting. Results Using the patient-derived cell culture models of polyQ diseases, we tested various siRNAs, and antisense reagents and assessed their silencing efficiency and allele selectivity. We showed considerable allele discrimination by several SNP targeting siRNAs based on a weak G-G or G-U pairing with normal allele and strong G-C pairing with mutant allele at the site of RISC-induced cleavage. Among the CAG repeat targeting reagents the strongest allele discrimination is achieved by miRNA-like functioning reagents that bind to their targets and inhibit their translation without substantial target cleavage. Also, morpholino analog performs well in mutant and normal allele discrimination but its efficient delivery to cells at low effective concentration still remains a challenge. Conclusions Using three cellular models of polyQ diseases and the same experimental setup we directly compared the performance of different oligonucleotide-based treatment strategies that are currently under development. Based on the results obtained by us and others we discussed the advantages and drawbacks of these strategies considering them from several different perspectives. The strategy aimed at nonallele-selective inhibiting of causative gene expression by targeting specific sequence of the implicated gene is the easiest to implement but relevant benefits are still uncertain. The gene replacement strategy that

  4. Targeted oligonucleotide-mediated microsatellite identification (TOMMI from large-insert library clones

    Directory of Open Access Journals (Sweden)

    Ren Jun


    Full Text Available Abstract Background In the last few years, microsatellites have become the most popular molecular marker system and have intensively been applied in genome mapping, biodiversity and phylogeny studies of livestock. Compared to single nucleotide polymorphism (SNP as another popular marker system, microsatellites reveal obvious advantages. They are multi-allelic, possibly more polymorphic and cheaper to genotype. Calculations showed that a multi-allelic marker system always has more power to detect Linkage Disequilibrium (LD than does a di-allelic marker system 1. Traditional isolation methods using partial genomic libraries are time-consuming and cost-intensive. In order to directly generate microsatellites from large-insert libraries a sequencing approach with repeat-containing oligonucleotides is introduced. Results Seventeen porcine microsatellite markers were isolated from eleven PAC clones by targeted oligonucleotide-mediated microsatellite identification (TOMMI, an improved efficient and rapid flanking sequence-based approach for the isolation of STS-markers. With the application of TOMMI, an average of 1.55 (CA/GT microsatellites per PAC clone was identified. The number of alleles, allele size distribution, polymorphism information content (PIC, average heterozygosity (HT, and effective allele number (NE for the STS-markers were calculated using a sampling of 336 unrelated animals representing fifteen pig breeds (nine European and six Chinese breeds. Sixteen of the microsatellite markers proved to be polymorphic (2 to 22 alleles in this heterogeneous sampling. Most of the publicly available (porcine microsatellite amplicons range from approximately 80 bp to 200 bp. Here, we attempted to utilize as much sequence information as possible to develop STS-markers with larger amplicons. Indeed, fourteen of the seventeen STS-marker amplicons have minimal allele sizes of at least 200 bp. Thus, most of the generated STS-markers can easily be

  5. Purification and characterization of oligonucleotide binding (OB)-fold protein from medicinal plant Tinospora cordifolia. (United States)

    Amir, Mohd; Haque, Md Anzarul; Wahiduzzaman; Dar, Mohammad Aasif; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz


    The oligonucleotide binding fold (OB-fold) is a small structural motif present in many proteins. It is originally named for its oligonucleotide or oligosaccharide binding properties. These proteins have been identified as essential for replication, recombination and repair of DNA. We have successfully purified a protein contains OB-fold from the stem of Tinospora cordifolia, a medicinal plants of north India. Stems were crushed and centrifuged, and fraction obtained at 60% ammonium sulphate was extensively dialyzed and applied to the weak anion exchange chromatography on Hi-Trap DEAE-FF in 50mM Tris-HCl buffer at pH 8.0. Eluted fractions were concentrated and applied to gel filtration column to get pure protein. We observed a single band of 20-kDa on SDS-PAGE. Finally, the protein was identified as OB-fold by MALDI-TOF. The purified OB-fold protein was characterized for its secondary structural elements using circular dichroism (CD) in the far-UV region. Generally the OB-fold has a characteristic feature as five-stranded beta-sheet coiled to form a closed beta- barrel. To estimate its chemical stability, guanidinium chloride-induced denaturation curve was followed by observing changes in the far-UV CD as a function of the denaturant concentration. Analysis of this denaturation curve gave values of 8.90±0.25kcalmol(-1) and 3.78±0.18M for ΔGD° (Gibbs free energy change at 25°C) and Cm (midpoint of denaturation), respectively. To determine heat stability parameters of OB-fold protein, differential scanning calorimetry was performed. Calorimetric values of ΔGD°, Tm (midpoint of denaturation), ΔHm (enthalpy change at Tm), and ΔCp (constant-pressure heat capacity change) are 9.05±0.27kcalmol(-1), 85.2±0,3°C, 105±4kcalmol(-1) and 1.6±0.08kcalmol(-1)K(-1). This is the first report on the isolation, purification and characterization of OB-fold protein from a medicinal plant T. cordifolia.

  6. Planetary nebulae abundances and stellar evolution

    CERN Document Server

    Pottasch, S R


    A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted from these gradients at the distance of the Sun from the center are exactly the solar abundance. Sulfur is the exception to this; the reason for this is discussed. The higher solar neon abundance is confirmed; this is discussed in terms of the results of helioseismology. Evidence is presented for oxygen destruction via ON cycling having occurred in the progenitors of four planetary nebulae with bilobal structure. These progenitor stars had a high mass, probably greater than 5 solar masses. This is deduced from the high values of He/H and N/H found in these nebulae. Formation of nitrogen, helium and carbon are discussed. The high mass progenitors which showed oxygen de...

  7. TEA: A Code Calculating Thermochemical Equilibrium Abundances (United States)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver


    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via

  8. Modelling Void Abundance in Modified Gravity

    CERN Document Server

    Voivodic, Rodrigo; Llinares, Claudio; Mota, David F


    We use a spherical model and an extended excursion set formalism with drifting diffusive barriers to predict the abundance of cosmic voids in the context of general relativity as well as f(R) and symmetron models of modified gravity. We detect spherical voids from a suite of N-body simulations of these gravity theories and compare the measured void abundance to theory predictions. We find that our model correctly describes the abundance of both dark matter and galaxy voids, providing a better fit than previous proposals in the literature based on static barriers. We use the simulation abundance results to fit for the abundance model free parameters as a function of modified gravity parameters, and show that counts of dark matter voids can provide interesting constraints on modified gravity. For galaxy voids, more closely related to optical observations, we find that constraining modified gravity from void abundance alone may be significantly more challenging. In the context of current and upcoming galaxy surv...

  9. The Common HOL Platform


    Adams, Mark


    The Common HOL project aims to facilitate porting source code and proofs between members of the HOL family of theorem provers. At the heart of the project is the Common HOL Platform, which defines a standard HOL theory and API that aims to be compatible with all HOL systems. So far, HOL Light and hol90 have been adapted for conformance, and HOL Zero was originally developed to conform. In this paper we provide motivation for a platform, give an overview of the Common HOL Platform's theory and...

  10. DNA microarray synthesis by using PDMS molecular stamp (II) -- Oligonucleotide on-chip synthesis using PDMS stamp

    Institute of Scientific and Technical Information of China (English)


    Based on the standard phosphoramidites chemistry protocol, two oligonucleotides synthetic routes were studied by contact stamping reactants to a modified glass slide. Route A was a contact coupling reaction, in which a nucleoside monomer was transferred and coupled to reactive groups (OH) on a substrate by spreading the nucleoside activated with tetrazole on a polydimethylsiloxane (PDMS) stamp. Route B was a contact detritylation, in which one nucleoside was fixed on the desired synthesis regions where dimethoxytrityl (DMT) protecting groups on the 5′-hydroxyl of the support-bound nucleoside were removed by stamping trichloroacetic acid (TCA) distributed on features on a PDMS stamp. Experiments showed that the synthetic yield and the reaction speed of route A were higher than those of route B. It was shown that 20 mer oligonucleotide arrays immobilized on the glass slide were successfully synthesized using the PDMS stamps, and the coupling efficiency showed no difference between the PDMS stamping and the conventional synthesis methods.

  11. Spectroscopic studies on the formation and thermal stability of DNA triplexes with a benzoannulated delta-carboline-oligonucleotide conjugate. (United States)

    Eick, Andrea; Xiao, Zhou; Langer, Peter; Weisz, Klaus


    A benzoannulated delta-carboline with a phenyl substituent has been covalently tethered to the 3'-end of a triplex-forming oligonucleotide and its ability to bind and stabilize DNA triple helices has been examined by various spectroscopic methods. UV thermal melting experiments were conducted with different hairpin duplexes and with a complementary single-stranded oligonucleotide as targets for the conjugate. The delta-carboline ligand preferentially binds triplexes over duplexes and leads to a temperature increase of the triplex-to-duplex transition by up to 23 degrees C. The results obtained from UV, CD and fluorescence measurements suggest that the delta-carboline ligand exhibits specific interactions with a triplex and favors binding by intercalation at the triplex-duplex junction.

  12. Studying the interactions of a platinum(II) 9-aminoacridine complex with proteins and oligonucleotides by ESI-TOF MS. (United States)

    Samper, Katia G; Vicente, Consuelo; Rodríguez, Venancio; Atrian, Sílvia; Cutillas, Natalia; Capdevila, Mercè; Ruiz, José; Palacios, Òscar


    The interaction of a novel Pt complex, [Pt(dmba)(N9-9AA)(PPh(3))](+)1 (dmba = N,N-dimethylbenzylamine-κN,κC; 9AA = 9-aminoacridine), which exhibits anti-tumor activity, with certain key proteins has been monitored by ESI-MS. Also, the interaction of 1 with a designed double-stranded oligonucleotide containing the GG motif has been followed by mass spectrometry as well as by fluorimetry. The results obtained show the low interaction of 1 with the considered proteins and the absence of covalent interaction with the oligonucleotides, but the fluorimetric data confirm the π-π interaction of 1 with the double-stranded DNA, which is probably the reason of the previously reported activity of 1 in several tumor cell lines.

  13. Increased electrocatalyzed performance through hairpin oligonucleotide aptamer-functionalized gold nanorods labels and graphene-streptavidin nanomatrix: Highly selective and sensitive electrochemical biosensor of carcinoembryonic antigen. (United States)

    Wen, Wei; Huang, Jing-Yi; Bao, Ting; Zhou, Jun; Xia, Hong-Xing; Zhang, Xiu-Hua; Wang, Sheng-Fu; Zhao, Yuan-Di


    We report a triplex signal amplification strategy for sensitive biosensing of cancer biomarker by taking advantage of hairpin-shaped oligonucleotide-functionalized gold nanorods (HO-GNRs), graphene and the avidin-biotin reation. The strategy expands electrochemical detection of carcinoembryonic antigen (CEA) by using an aptamer as biosensor's recognition element and HO-GNRs as signal enhancer. To construct this biosensor, the GNR was used as a carrier of horseradish peroxidase (HRP) and HO aptamer with a biotin at the 3'-end and a thiol at the 5'-end, which amplified the electrochemical response because of a large molar ratio of HRP to HO. In the presence of target CEA, the binding reactions of CEA with the loop portions of the HOs caused HOs' loop-stem structure opened and exposed the biotins, and then HRP-GNRs-HO conjugates were captured on graphene and streptavidin modified electrodes via the reaction between the exposed biotins and preimmobilized streptavidins. The accumulation of HRP effectively catalyzed the hydrogen peroxide-mediated oxidation of o-phenylenediamine to generate an electrochemical reduction current for CEA detection. Under optimal conditions, the electrochemical biosensor exhibited a wide dynamic range of 5pgmL(-1) and 50ngmL(-1) toward CEA standards with a low detection limit of 1.5pgmL(-1) (signal-to-noise ratio of 3). The proposed biosensor accurately detected CEA concentration in 8 human serum samples from patients with lung diseases, showing excellent correlations with standard chemiluminescence immunoassay. Furthermore, these results of target DNA detection made it abundantly clear that the proposed strategy can also be extended for detection of other relative biomarkers using different functional DNA structures, which shows great prospects in single-nucleotide polymorphisms analysis, biomedical sensing and application for accurate clinical diseases diagnostic.

  14. PLGA-PEG-PLGA microspheres as a delivery vehicle for antisense oligonucleotides to CTGF: Implications on post-surgical peritoneal adhesion prevention (United States)

    Azeke, John Imuetinyan-Jesu, Jr.

    Abdominal adhesions are the aberrant result of peritoneal wound healing commonly associated with surgery and inflammation. A subject of a large number of studies since the first half of the last century, peritoneal adhesion prevention has, for the most part, evaded the scientific community and continues to cost Americans an estimated $2-4 billion annually. It is known that transforming growth factor-beta (TGF-beta) plays a key role in the wound healing cascade; however, suppression of this multifunctional growth factor's activity may have more harmful consequences than can be tolerated. As a result, much attention has fallen on connective tissue growth factor (CTGF), a downstream mediator of TGF-beta's fibrotic action. It has been demonstrated in several in vitro models, that the suppression of CTGF hinders fibroblast proliferation, a necessary condition for fibrosis. Furthermore, antisense oligonucleotides (antisense oligos, AO) to CTGF have been shown to knock down CTGF mRNA levels by specifically hindering the translation of CTGF protein. Antisense technologies have met with a great deal of excitement as a viable means of preventing diseases such as adhesions by hindering protein translation at the mRNA level. However, the great challenge associated with the use of these drugs lies in the short circulation time when administered "naked". Viral delivery systems, although excellent platforms in metabolic studies, are not ideal for diagnostic use because of the inherent danger associated with viral vectors. Microparticles made of biodegradable polymers have therefore presented themselves as a viable means of delivering these drugs to target cells over extended periods. Herein, we present two in vivo studies confirming the up-regulation of TGF-beta protein and CTGF mRNA following injury to the uterine tissues of female rats. We were able to selectively knockdown post-operative CTGF protein levels following surgery, however, our observations led us to conclude that

  15. Common Misconceptions about Cholesterol (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Common Misconceptions about Cholesterol Updated:Apr 3,2017 Cholesterol can be both ... misconceptions about cholesterol. Click on each misconception about cholesterol to see the truth: My choices about diet ...

  16. Genomic Data Commons launches (United States)

    The Genomic Data Commons (GDC), a unified data system that promotes sharing of genomic and clinical data between researchers, launched today with a visit from Vice President Joe Biden to the operations center at the University of Chicago.

  17. Common Knowledge on Networks

    CERN Document Server

    Liddell, Torrin M


    Common knowledge of intentions is crucial to basic social tasks ranging from cooperative hunting to oligopoly collusion, riots, revolutions, and the evolution of social norms and human culture. Yet little is known about how common knowledge leaves a trace on the dynamics of a social network. Here we show how an individual's network properties---primarily local clustering and betweenness centrality---provide strong signals of the ability to successfully participate in common knowledge tasks. These signals are distinct from those expected when practices are contagious, or when people use less-sophisticated heuristics that do not yield true coordination. This makes it possible to infer decision rules from observation. We also find that tasks that require common knowledge can yield significant inequalities in success, in contrast to the relative equality that results when practices spread by contagion alone.

  18. ACS: ALMA Common Software (United States)

    Chiozzi, Gianluca; Šekoranja, Matej


    ALMA Common Software (ACS) provides a software infrastructure common to all ALMA partners and consists of a documented collection of common patterns and components which implement those patterns. The heart of ACS is based on a distributed Component-Container model, with ACS Components implemented as CORBA objects in any of the supported programming languages. ACS provides common CORBA-based services such as logging, error and alarm management, configuration database and lifecycle management. Although designed for ALMA, ACS can and is being used in other control systems and distributed software projects, since it implements proven design patterns using state of the art, reliable technology. It also allows, through the use of well-known standard constructs and components, that other team members whom are not authors of ACS easily understand the architecture of software modules, making maintenance affordable even on a very large project.

  19. Five Common Glaucoma Tests (United States)

    ... About Us Donate In This Section Five Common Glaucoma Tests en Español email Send this article to ... year or two after age 35. A Comprehensive Glaucoma Exam To be safe and accurate, five factors ...

  20. MA Common Tern Census (United States)

    US Fish and Wildlife Service, Department of the Interior — The official State census period for common terns was June 1-10. The survey was conducted on June 4 by Biologist Healey, Biotech Springfield, and Maintenance...

  1. Allyl group as a protecting group for internucleotide phosphate and thiophosphate linkages in oligonucleotide synthesis: facile oxidation and deprotection conditions. (United States)

    Manoharan, M; Lu, Y; Casper, M D; Just, G


    [reaction: see text] The allyl group, which serves as a protecting group for an internucleotide bond for both phosphates and phosphorothioates, can be easily removed by good nucleophiles under weakly basic or neutral conditions. For a practical synthesis on solid support, camphorsulfonyloxaziridine was used as the oxidizing agent for synthesizing DNA, while the Beaucage reagent was used for preparing phosphorothioate oligomers. Both types of oligonucleotides were easily deprotected by concentrated ammonium hydroxide containing 2% mercaptoethanol.

  2. Detection and identification of enterohemorrhagic Escherichia coli O157:H7 and Vibrio cholerae O139 using oligonucleotide microarray

    Directory of Open Access Journals (Sweden)

    Zhang Zheng


    Full Text Available Abstract Background The rapid and accurate detection and identification of the new subtype of the pathogens is crucial for diagnosis, treatment and control of the contagious disease outbreak. Here, in this study, an approach to detect and identify Escherichia coli O157:H7 and Vibrio cholerae O139 was established using oligonucleotide microarray. We coupled multiplex PCR with oligonucleotide microarray to construct an assay suitable for simultaneous identification of two subtypes of the pathogens. Results The stx1, stx2 gene and uidA gene having the specific mutant spot were chosen as the targets for Escherichia coli O157:H7, and meanwhile the ctxA, tcpA, and LPSgt gene for Vibrio cholerae O139. The oligonucleotide microarray was composed of eight probes including negative control and positive control from 16S rDNA gene. The six primers were designed to amplify target fragments in two triplex PCR, and then hybridized with oligonucleotide microarray. An internal control would be to run a PCR reaction in parallel. Multiplex PCR did not produce any non-specific amplicons when 149 related species or genera of standard bacteria were tested (100% specificity. In addition, Escherichia coli O157:H7 and Escherichia coli O157:non-H7, Vibrio cholerae O139 and Vibrio cholerae O1 had been discriminated respectively. Using recombinant plasmid and target pathogens, we were able to detect positive hybridization signals with 102 copies/μL and 103 cfu/mL per reaction. Conclusion The DNA microarray assay reported here could detect and identify Escherichia coli O157:H7 and Vibrio cholerae O139, and furthermore the subtype was distinguished. This assay was a specific and sensitive tool for simultaneous detection and identification of the new subtype of two pathogens causing diarrhea in human.

  3. Fast and simple anion-exchange chromatography for large-scale purification of self-complementary oligonucleotides. (United States)

    Banerjee, A; Bose, H S; Roy, K B


    A fast and simple anion-exchange chromatography method is described for large-scale purification of synthetic oligonucleotides. Using a single matrix and aqueous solvent system, the two-step chromatographic procedure can handle complex separation problems of self-complementary or G-rich sequences without the use of urea or formaldehyde. The work also demonstrates the complication encountered, possibly due to hairpin formation, in one of the oligomers.

  4. Kinetics of hybridization on surface oligonucleotide microchips: theory, experiment, and comparison with hybridization on gel-based microchips. (United States)

    Sorokin, N V; Chechetkin, V R; Pan'kov, S V; Somova, O G; Livshits, M A; Donnikov, M Y; Turygin, A Y; Barsky, V E; Zasedatelev, A S


    The optimal design of oligonucleotide microchips and efficient discrimination between perfect and mismatch duplexes strongly depend on the external transport of target DNA to the cells with immobilized probes as well as on respective association and dissociation rates at the duplex formation. In this paper we present the relevant theory for hybridization of DNA fragments with oligonucleotide probes immobilized in the cells on flat substrate. With minor modifications, our theory also is applicable to reaction-diffusion hybridization kinetics for the probes immobilized on the surface of microbeads immersed in hybridization solution. The main theoretical predictions are verified with control experiments. Besides that, we compared the characteristics of the surface and gel-based oligonucleotide microchips. The comparison was performed for the chips printed with the same pin robot, for the signals measured with the same devices and processed by the same technique, and for the same hybridization conditions. The sets of probe oligonucleotides and the concentrations of probes in respective solutions used for immobilization on each platform were identical as well. We found that, despite the slower hybridization kinetics, the fluorescence signals and mutation discrimination efficiency appeared to be higher for the gel-based microchips with respect to their surface counterparts even for the relatively short hybridization time about 0.5-1 hour. Both the divergence between signals for perfects and the difference in mutation discrimination efficiency for the counterpart platforms rapidly grow with incubation time. In particular, for hybridization during 3 h the signals for gel-based microchips surpassed their surface counterparts in 5-20 times, while the ratios of signals for perfect-mismatch pairs for gel microchips exceeded the corresponding ratios for surface microchips in 2-4 times. These effects may be attributed to the better immobilization efficiency and to the higher

  5. In vivo alteration of the keratin 17 gene in hair follicles by oligonucleotide-directed gene targeting. (United States)

    Fan, W; Yoon, K


    Using intradermal injection of a chimeric RNA-DNA oligonucleotide (RDO) or a single-stranded oligonucleotide (ssODN) into murine skin, we attempted to make a dominant mutation (R94p) in the conserve alpha-helical domain of keratin 17 (K17), the same mutation found in pachyononychia congenichia type 2 (PC-2) patients with phenotypes ranging from twisted hair and multiple pilosebaceous cysts. Both K17A-RDO and -ssODN contained a single base mismatch (CGC to CCC) to alter the normal K17 sequence to cause an amino acid substitution (R94P). The complexes consisting of oligonucleotides and cationic liposomes were injected to C57B1/6 murine skin at 2 and 5 day after birth. Histological examination of skin biopsies at postnatal day 8 from several mice showed consistent twisted hair shafts or broken hair follicles at the sebaceous gland level and occasional rupture of the hair bulb or epidermal cyst-like changes. In the injected area, the number of full anagen hair follicles decrease by 50%. Injection of the control oligonucleotide, identical to K17A-RDO but containing no mismatch to the normal sequence, did not result in any detectable abnormality. The frequency of gene alteration was lower than 3%, according to the restriction fragment length polymorphism (RFLP) analysis of the genomic DNA isolated by dissection of hair follicles from slides. Although intradermal injection of K17A-RDO or K17-ssODN caused a dominant mutation in K17 affecting hair growth and morphology, these phenotypic changes were transient either due to the compensation of K17 by other keratins or the replacement of the mutated cells by normal surrounding cells during hair growth.

  6. The distribution and abundance of interstellar C2H (United States)

    Huggins, P. J.; Carlson, W. J.; Kinney, A. L.


    C2H(N = 1-0) emission has been extensively observed in a variety of molecular clouds, including: 12 hot, dense, cloud cores, 3 bright-rimmed clouds (in NGC 1977, IC 1396, and IC 1848), and across the extended OMC - 1 cloud. It has also been observed in the circumstellar envelopes IRC + 10216 and AFGL 2688. Abundance analyses of the molecular clouds yield C2H/(C-13)O abundance ratios of about 0.01, with little variation (less than about a factor of 4) either between clouds or across individual clouds. In the Orion plateau source, the C2H abundance is enhanced by less than a factor of 4, relative to the extended cloud. The generally high levels of C2H found in the molecular clouds are not readily accounted for by simple, steady-state chemical models, and suggest, as do earlier observations of atomic carbon, that the carbon chemistry in dense clouds is more active than is commonly assumed.

  7. Superflare G and K Stars and the Lithium abundance

    CERN Document Server

    Katsova, M M; Mishenina, T V; Nizamov, B A


    We analyzed here the connection of superflares and the lithium abundance in G and K stars based on Li abundance determinations conducted with the echelle spectra of a full set of 280 stars obtained with the ELODIE spectrograph. For high-active stars we show a definite correlation between $\\log A(Li)$ and the chromosphere activity. We show that sets of stars with high Li abundance and having superflares possess common properties. It relates, firstly, to stars with activity saturation. We consider the X-ray data for G, K, and M stars separately, and show that transition from a saturation mode to solar-type activity takes place at values of rotation periods 1.1, 3.3, and 7.2 days for G2, K4 and M3 spectral types, respectively. We discuss bimodal distribution of a number of G and K main-sequence stars versus an axial rotation and location of superflare stars with respect to other Kepler stars. We conclude that superflare G and K stars are mainly fast rotating young objects, but some of them belong to stars with s...



    Bromley, Daniel W.; Cochrane, Jeffrey A.


    We want to clarify the way in which we think about the global commons, particularly the problem of global warming caused by greenhouse gas emissions and tropical deforestation. We develop a policy framework in which the policy goal is the sustainability of the earth's ability to absorb greenhouse gases. The framework considers the unequal incidence of benefits and costs of particular policies. We identify several resource management regimes and suggest that management under a common property ...

  9. Common clay and shale (United States)

    Virta, R.L.


    The article discusses the latest developments in the global common clay and shale industry, particularly in the U.S. It claims that common clay and shale is mainly used in the manufacture of heavy clay products like brick, flue tile and sewer pipe. The main producing states in the U.S. include North Carolina, New York and Oklahoma. Among the firms that manufacture clay and shale-based products are Mid America Brick & Structural Clay Products LLC and Boral USA.

  10. A web-based search engine for triplex-forming oligonucleotide target sequences. (United States)

    Gaddis, Sara S; Wu, Qi; Thames, Howard D; DiGiovanni, John; Walborg, Earl F; MacLeod, Michael C; Vasquez, Karen M


    Triplex technology offers a useful approach for site-specific modification of gene structure and function both in vitro and in vivo. Triplex-forming oligonucleotides (TFOs) bind to their target sites in duplex DNA, thereby forming triple-helical DNA structures via Hoogsteen hydrogen bonding. TFO binding has been demonstrated to site-specifically inhibit gene expression, enhance homologous recombination, induce mutation, inhibit protein binding, and direct DNA damage, thus providing a tool for gene-specific manipulation of DNA. We have developed a flexible web-based search engine to find and annotate TFO target sequences within the human and mouse genomes. Descriptive information about each site, including sequence context and gene region (intron, exon, or promoter), is provided. The engine assists the user in finding highly specific TFO target sequences by eliminating or flagging known repeat sequences and flagging overlapping genes. A convenient way to check for the uniqueness of a potential TFO binding site is provided via NCBI BLAST. The search engine may be accessed at

  11. A Versatile Vector for Gene and Oligonucleotide Transfer into Cells in Culture and in vivo: Polyethylenimine (United States)

    Boussif, Otmane; Lezoualc'h, Frank; Zanta, Maria Antonietta; Djavaheri Mergny, Mojgan; Scherman, Daniel; Demeneix, Barbara; Behr, Jean-Paul


    Several polycations possessing substantial buffering capacity below physiological pH, such as lipopolyamines and polyamidoamine polymers, are efficient transfection agents per se-i.e., without the addition of cell targeting or membrane-disruption agents. This observation led us to test the cationic polymer polyethylenimine (PEI) for its genedelivery potential. Indeed, every third atom of PEI is a protonable amino nitrogen atom, which makes the polymeric network an effective "proton sponge" at virtually any pH. Luciferase reporter gene transfer with this polycation into a variety of cell lines and primary cells gave results comparable to, or even better than, lipopolyamines. Cytotoxicity was low and seen only at concentrations well above those required for optimal transfection. Delivery of oligonucleotides into embryonic neurons was followed by using a fluorescent probe. Virtually all neurons showed nuclear labeling, with no toxic effects. The optimal PEI cation/anion balance for in vitro transfection is only slightly on the cationic side, which is advantageous for in vivo delivery. Indeed, intracerebral luciferase gene transfer into newborn mice gave results comparable (for a given amount of DNA) to the in vitro transfection of primary rat brain endothelial cells or chicken embryonic neurons. Together, these properties make PEI a promising vector for gene therapy and an outstanding core for the design of more sophisticated devices. Our hypothesis is that its efficiency relies on extensive lysosome buffering that protects DNA from nuclease degradation, and consequent lysosomal swelling and rupture that provide an escape mechanism for the PEI/DNA particles.

  12. Identification of upper respiratory tract pathogens using electrochemical detection on an oligonucleotide microarray.

    Directory of Open Access Journals (Sweden)

    Michael J Lodes

    Full Text Available Bacterial and viral upper respiratory infections (URI produce highly variable clinical symptoms that cannot be used to identify the etiologic agent. Proper treatment, however, depends on correct identification of the pathogen involved as antibiotics provide little or no benefit with viral infections. Here we describe a rapid and sensitive genotyping assay and microarray for URI identification using standard amplification and hybridization techniques, with electrochemical detection (ECD on a semiconductor-based oligonucleotide microarray. The assay was developed to detect four bacterial pathogens (Bordetella pertussis, Streptococcus pyogenes, Chlamydia pneumoniae and Mycoplasma pneumoniae and 9 viral pathogens (adenovirus 4, coronavirus OC43, 229E and HK, influenza A and B, parainfluenza types 1, 2, and 3 and respiratory syncytial virus. This new platform forms the basis for a fully automated diagnostics system that is very flexible and can be customized to suit different or additional pathogens. Multiple probes on a flexible platform allow one to test probes empirically and then select highly reactive probes for further iterative evaluation. Because ECD uses an enzymatic reaction to create electrical signals that can be read directly from the array, there is no need for image analysis or for expensive and delicate optical scanning equipment. We show assay sensitivity and specificity that are excellent for a multiplexed format.

  13. Assessment of the cellular internalization of thermolytic phosphorothioate DNA oligonucleotide prodrugs. (United States)

    Jain, Harsh V; Takeda, Kazuyo; Tami, Cecilia; Verthelyi, Daniela; Beaucage, Serge L


    The bioactivity of a CpG-containing phosphorothioate DNA oligonucleotide with thermolytic 2-(N-formyl-N-methylamino)ethyl (fma) thiophosphate groups in mice led us to investigate the parameters affecting the internalization of these thermosensitive DNA prodrugs in various cell lines. Flow cytometry and confocal microscopy analyses indicate that 5'-fluoresceinated fma-phosphorothioate DNA sequences are poorly internalized in Vero, HeLa and GC-2 cells. However, when four fma-thiophosphate groups of a 15-nucleotide long oligothymidylate prodrug are replaced with 3-(N,N-dimethylamino)prop-1-yl thiophosphate functions, internalization of the positively charged prodrug, under physiological conditions, increased fourfold in HeLa and 40-fold in Vero or GC-2 cells. No cytotoxic effects are observed in Vero cells even at an extracellular prodrug concentration of 50 μM over a period of 72 h. Confocal microscopy studies show that internalization of the positively charged oligothymidylate prodrug in Vero cells is time-dependent with early trafficking of the DNA sequence through endosomal vesicles and, eventually, to the nucleus of the cells. Thus, the incorporation of four 3-(N,N-dimethylamino)prop-1-yl thiophosphate groups into thermosentive fma-phosphorothioate DNA prodrugs is an attractive strategy for efficient cellular internalization of these nucleic acid-based drugs for potential therapeutic indications.

  14. Priming DNA Replication from Triple Helix Oligonucleotides: Possible Threestranded DNA in DNA Polymerases

    Directory of Open Access Journals (Sweden)

    Patrick P. Lestienne


    Full Text Available Triplex associate with a duplex DNA presenting the same polypurine or polypyrimidine-rich sequence in an antiparallel orientation. So far, triplex forming oligonucleotides (TFOs are known to inhibit transcription, replication, and to induce mutations. A new property of TFO is reviewed here upon analysis of DNA breakpoint yielding DNA rearrangements; the synthesized sequence of the first direct repeat displays a skewed polypurine- rich sequence. This synthesized sequence can bind the second homologous duplex sequence through the formation of a triple helix, which is able to prime further DNA replication. In these case, the d(G-rich Triple Helix Primers (THP bind the homologous strand in a parallel manner, possibly via a RecA-like mechanism. This novel property is shared by all tested DNA polymerases: phage, retrovirus, bacteria, and human. These features may account for illegitimate initiation of replication upon single-strand breakage and annealing to a homologous sequence where priming may occur. Our experiments suggest that DNA polymerases can bind three instead of two polynucleotide strands in their catalytic centre.

  15. Establishment of a Predictive In Vitro Assay for Assessment of the Hepatotoxic Potential of Oligonucleotide Drugs (United States)

    Sewing, Sabine; Boess, Franziska; Moisan, Annie; Bertinetti-Lapatki, Cristina; Minz, Tanja; Hedtjaern, Maj; Tessier, Yann; Schuler, Franz; Singer, Thomas; Roth, Adrian B.


    Single stranded oligonucleotides (SSO) represent a novel therapeutic modality that opens new space to address previously undruggable targets. In spite of their proven efficacy, the development of promising SSO drug candidates has been limited by reported cases of SSO-associated hepatotoxicity. The mechanisms of SSO induced liver toxicity are poorly understood, and up to now no preclinical in vitro model has been established that allows prediction of the hepatotoxicity risk of a given SSO. Therefore, preclinical assessment of hepatic liability currently relies on rodent studies that require large cohorts of animals and lengthy protocols. Here, we describe the establishment and validation of an in vitro assay using primary hepatocytes that recapitulates the hepatotoxic profile of SSOs previously observed in rodents. In vitro cytotoxicity upon unassisted delivery was measured as an increase in extracellular lactate dehydrogenase (LDH) levels and concomitant reduction in intracellular glutathione and ATP levels after 3 days of treatment. Furthermore, toxic, but not safe, SSOs led to an increase in miR-122 in cell culture supernatants after 2 days of exposure, revealing the potential use of miR122 as a selective translational biomarker for detection of SSO-induced hepatotoxicity. Overall, we have developed and validated for the first time a robust in vitro screening assay for SSO liver safety profiling which allows rapid prioritization of candidate molecules early on in development. PMID:27442522


    Institute of Scientific and Technical Information of China (English)


    For investigating the possibility of applying degenerate oligonucleotide primer PCR (DOP-PCR) and comparative genomic hybridization (CGH) technique to analyses of genomic genetics in a single cell, the whole genomic DNA of a single cell with XX, XY, XO, XXY, +13 or +21 was amplified by DOP-PCR. Single cell DOP-PCR CGHs with conventional and modified control references, the genomic DNA and a single cell DOP-PCR product from normal male, were carried out respectively. The results showed that the average profile of the fluorescence intensity ratio in CGH with the genomic DNA as reference fluctuates much and that the standard deviation in about 30% haploid is beyond the normal limits. False positive hyper-representation was found to exist in X chromosome while trisomy 13 and 21 were not detected. However, the distributions of the mean and the standard deviation of the ratio in the CGH with DOP-PCR product as reference were quite acceptable. The copy number changes of chromosome X,Y,13 and 21 were revealed. Those results suggested that there is unrandom unequal amplification in a single cell DOP-PCR. Using a single DOP-PCR product as reference can decrease its influence on CGH. Single cell DOP-PCR-CGH and its application in the genetic analyses of preimplantation embryo or fetal cell in maternal blood may be possible.

  17. Oligonucleotide-stabilized fluorescent silver nanoclusters for the specific and sensitive detection of biotin. (United States)

    Xiong, Xiaoli; Tang, Yan; Zhao, Jingjin; Zhao, Shulin


    A novel biotin fluorescent probe based on oligonucleotide-stabilized silver nanoclusters (DNA-AgNCs) was synthesized by employing a biotinylated cytosine-rich sequence as a synthesized template. The fluorescence properties of the DNA-AgNCs are related to the modified position of the DNA. When biotin is linked to the middle thymine base of the DNA sequence, the DNA-AgNCs emit the strongest fluorescence. Moreover, the stability of the DNA-AgNCs was affected by avidin through biotin-avidin binding, quenching the fluorescence of the DNA-AgNCs. In contrast, if free biotin is further introduced into this system, the quenching is apparently weakened by competition, leading to the restoration of fluorescence. This phenomenon can be utilized for the detection of biotin. Under the optimal conditions, the fluorescence recovery is linearly proportional to the concentration of biotin in the range of 10 nM-1.0 μM with a detection limit of 6.0 nM. This DNA-AgNCs probe with excellent fluorescent properties is sensitive and selective for the detection of biotin and has been applied for the determination of biotin in wheat flour.

  18. Oligonucleotide microarray identifies genes differentially expressed during tumorigenesis of DMBA-induced pancreatic cancer in rats.

    Directory of Open Access Journals (Sweden)

    Jun-Chao Guo

    Full Text Available The extremely dismal prognosis of pancreatic cancer (PC is attributed, at least in part, to lack of early diagnosis. Therefore, identifying differentially expressed genes in multiple steps of tumorigenesis of PC is of great interest. In the present study, a 7,12-dimethylbenzanthraene (DMBA-induced PC model was established in male Sprague-Dawley rats. The gene expression profile was screened using an oligonucleotide microarray, followed by real-time quantitative polymerase chain reaction (qRT-PCR and immunohistochemical staining validation. A total of 661 differentially expressed genes were identified in stages of pancreatic carcinogenesis. According to GO classification, these genes were involved in multiple molecular pathways. Using two-way hierarchical clustering analysis, normal pancreas, acute and chronic pancreatitis, PanIN, early and advanced pancreatic cancer were completely discriminated. Furthermore, 11 upregulated and 142 downregulated genes (probes were found by Mann-Kendall trend Monotone test, indicating homologous genes of rat and human. The qRT-PCR and immunohistochemistry analysis of CXCR7 and UBe2c, two of the identified genes, confirmed the microarray results. In human PC cell lines, knockdown of CXCR7 resulted in decreased migration and invasion. Collectively, our data identified several promising markers and therapeutic targets of PC based on a comprehensive screening and systemic validation.

  19. Complete genome sequence of Treponema pallidum ssp. pallidum strain SS14 determined with oligonucleotide arrays

    Directory of Open Access Journals (Sweden)

    Sodergren Erica


    Full Text Available Abstract Background Syphilis spirochete Treponema pallidum ssp. pallidum remains the enigmatic pathogen, since no virulence factors have been identified and the pathogenesis of the disease is poorly understood. Increasing rates of new syphilis cases per year have been observed recently. Results The genome of the SS14 strain was sequenced to high accuracy by an oligonucleotide array strategy requiring hybridization to only three arrays (Comparative Genome Sequencing, CGS. Gaps in the resulting sequence were filled with targeted dideoxy-terminators (DDT sequencing and the sequence was confirmed by whole genome fingerprinting (WGF. When compared to the Nichols strain, 327 single nucleotide substitutions (224 transitions, 103 transversions, 14 deletions, and 18 insertions were found. On the proteome level, the highest frequency of amino acid-altering substitution polymorphisms was in novel genes, while the lowest was in housekeeping genes, as expected by their evolutionary conservation. Evidence was also found for hypervariable regions and multiple regions showing intrastrain heterogeneity in the T. pallidum chromosome. Conclusion The observed genetic changes do not have influence on the ability of Treponema pallidum to cause syphilitic infection, since both SS14 and Nichols are virulent in rabbit. However, this is the first assessment of the degree of variation between the two syphilis pathogens and paves the way for phylogenetic studies of this fascinating organism.

  20. Splice-correcting oligonucleotides restore BTK function in X-linked agammaglobulinemia model. (United States)

    Bestas, Burcu; Moreno, Pedro M D; Blomberg, K Emelie M; Mohammad, Dara K; Saleh, Amer F; Sutlu, Tolga; Nordin, Joel Z; Guterstam, Peter; Gustafsson, Manuela O; Kharazi, Shabnam; Piątosa, Barbara; Roberts, Thomas C; Behlke, Mark A; Wood, Matthew J A; Gait, Michael J; Lundin, Karin E; El Andaloussi, Samir; Månsson, Robert; Berglöf, Anna; Wengel, Jesper; Smith, C I Edvard


    X-linked agammaglobulinemia (XLA) is an inherited immunodeficiency that results from mutations within the gene encoding Bruton's tyrosine kinase (BTK). Many XLA-associated mutations affect splicing of BTK pre-mRNA and severely impair B cell development. Here, we assessed the potential of antisense, splice-correcting oligonucleotides (SCOs) targeting mutated BTK transcripts for treating XLA. Both the SCO structural design and chemical properties were optimized using 2'-O-methyl, locked nucleic acid, or phosphorodiamidate morpholino backbones. In order to have access to an animal model of XLA, we engineered a transgenic mouse that harbors a BAC with an authentic, mutated, splice-defective human BTK gene. BTK transgenic mice were bred onto a Btk knockout background to avoid interference of the orthologous mouse protein. Using this model, we determined that BTK-specific SCOs are able to correct aberrantly spliced BTK in B lymphocytes, including pro-B cells. Correction of BTK mRNA restored expression of functional protein, as shown both by enhanced lymphocyte survival and reestablished BTK activation upon B cell receptor stimulation. Furthermore, SCO treatment corrected splicing and restored BTK expression in primary cells from patients with XLA. Together, our data demonstrate that SCOs can restore BTK function and that BTK-targeting SCOs have potential as personalized medicine in patients with XLA.

  1. Droplet Digital Enzyme-Linked Oligonucleotide Hybridization Assay for Absolute RNA Quantification (United States)

    Guan, Weihua; Chen, Liben; Rane, Tushar D.; Wang, Tza-Huei


    We present a continuous-flow droplet-based digital Enzyme-Linked Oligonucleotide Hybridization Assay (droplet digital ELOHA) for sensitive detection and absolute quantification of RNA molecules. Droplet digital ELOHA incorporates direct hybridization and single enzyme reaction via the formation of single probe-RNA-probe (enzyme) complex on magnetic beads. It enables RNA detection without reverse transcription and PCR amplification processes. The magnetic beads are subsequently encapsulated into a large number of picoliter-sized droplets with enzyme substrates in a continuous-flow device. This device is capable of generating droplets at high-throughput. It also integrates in-line enzymatic incubation and detection of fluorescent products. Our droplet digital ELOHA is able to accurately quantify (differentiate 40% difference) as few as ~600 RNA molecules in a 1 mL sample (equivalent to 1 aM or lower) without molecular replication. The absolute quantification ability of droplet digital ELOHA is demonstrated with the analysis of clinical Neisseria gonorrhoeae 16S rRNA to show its potential value in real complex samples.

  2. Targeting duplex DNA with chimeric α,β-triplex-forming oligonucleotides (United States)

    Kolganova, N. A.; Shchyolkina, A. K.; Chudinov, A. V.; Zasedatelev, A. S.; Florentiev, V. L.; Timofeev, E. N.


    Triplex-directed DNA recognition is strictly limited by polypurine sequences. In an attempt to address this problem with synthetic biology tools, we designed a panel of short chimeric α,β-triplex-forming oligonucleotides (TFOs) and studied their interaction with fluorescently labelled duplex hairpins using various techniques. The hybridization of hairpin with an array of chimeric probes suggests that recognition of double-stranded DNA follows complicated rules combining reversed Hoogsteen and non-canonical homologous hydrogen bonding. In the presence of magnesium ions, chimeric TFOs are able to form highly stable α,β-triplexes, as indicated by native gel-electrophoresis, on-array thermal denaturation and fluorescence-quenching experiments. CD spectra of chimeric triplexes exhibited features typically observed for anti-parallel purine triplexes with a GA or GT third strand. The high potential of chimeric α,β-TFOs in targeting double-stranded DNA was demonstrated in the EcoRI endonuclease protection assay. In this paper, we report, for the first time, the recognition of base pair inversions in a duplex by chimeric TFOs containing α-thymidine and α-deoxyguanosine. PMID:22641847

  3. Gene Expression Profile Differences in Gastric Cancer and Normal Gastric Mucosa by Oligonucleotide Microarrays

    Institute of Scientific and Technical Information of China (English)

    Chuanding Yu; Shenhua Xu; HangZhou Mou; Zhiming Jiang; Chihong Zhu; Xianglin Liu


    OBJECTIVE To study the difference of gene expression in gastric cancer (T) and normal tissue of gastric mucosa (C), and to screen for associated novel genes in gastric cancers by oligonucleotide microarrays.METHODS U133A (Affymetrix, Santa Clara, CA) gene chip was used to detect the gene expression profile difference in T and C. Bioinformatics was used to analyze the detected results.RESULTS When gastric cancers were compared with normal gastric mucosa, a total of 270 genes were found with a difference of more than 9times in expression levels. Of the 270 genes, 157 were up-regulated (Signal Log Ratio [SLR] ≥3), and 113 were down-regulated (SLR ≤-3).Using a classification of function, the highest number of gene expression differences related to enzymes and their regulatory genes (67, 24.8%),followed by signal-transduction genes (43,15.9%). The third were nucleic acid binding genes (17, 6.3%), fourth were transporter genes (15, 5.5%)and fifth were protein binding genes (12, 4.4%). In addition there were 50genes of unknown function, accounting for 18.5%. The five above mentioned groups made up 56.9% of the total gene number.CONCLUSION The 5 gene groups (enzymes and their regulatory proteins, signal transduction proteins, nucleic acid binding proteins, transporter and protein binding) were abnormally expressed and are important genes for further study in gastric cancers.

  4. Detection of mammalian microRNA expression by in situ hybridization with RNA oligonucleotides. (United States)

    Deo, Monika; Yu, Jenn-Yah; Chung, Kwan-Ho; Tippens, Melissa; Turner, David L


    We have developed an in situ hybridization procedure for the detection of microRNAs (miRNAs) in tissue sections from mouse embryos and adult organs. The method uses highly specific washing conditions for RNA oligonucleotide probes conjugated to a fluorescein hapten. We show that this method detects predominantly mature miRNAs rather than the miRNA precursors or primary transcripts. We have determined expression patterns for several miRNAs expressed in the developing and adult nervous system, including miR-124a, miR-9, miR-92, and miR-204. Whereas miR-124a is expressed in neurons, miR-9 is expressed in neural progenitors and some neurons, and miR-204 is expressed in the choroid plexus, retinal pigment epithelium, and ciliary body. miR-204 is located in an intron of the TRPM3 gene, and the TRPM3 mRNA is coexpressed with miR-204 in the choroid plexus. We also find that primary transcripts for miR-124a and miR-9 genes are expressed in patterns similar to their respective mature miRNAs. The ability to visualize expression of specific miRNAs in embryos and tissues should aid studies on miRNA function.

  5. Gold Nanoparticle Aggregation for Quantification of Oligonucleotides: Optimization and Increased Dynamic Range (United States)

    Cordray, Michael S.; Amdahl, Matthew; Richards-Kortum, Rebecca R.


    A variety of assays have been proposed to detect small quantities of nucleic acids at the point-of-care. One approach relies on target-induced aggregation of gold nanoparticles functionalized with oligonucleotide sequences complementary to adjacent regions on the targeted sequence. In the presence of the target sequence, the gold nanoparticles aggregate, producing an easily detectable shift in the optical scattering properties of the solution. The major limitations of this assay are that it requires heating, and that long incubation times are required to produce a result. This study aims to optimize the assay conditions and optical readout, with the goals of eliminating the need for heating and reducing the time to result without sacrificing sensitivity or dynamic range. By optimizing assay conditions and measuring the spectrum of scattered light at the endpoint of incubation, we find that the assay is capable of producing quantifiable results at room temperature in 30 minutes with a linear dynamic range spanning from 150 amoles to 15 fmoles of target. If changes in light scattering are measured dynamically during the incubation process, the linear range can be expanded 2-fold, spanning 50 amoles to 500 fmoles, while decreasing the time to result down to 10 minutes. PMID:23000603

  6. The Preparation of New Phosphorus-Centered Functional Groups for Modified Oligonucleotides and Other Natural Phosphates

    Directory of Open Access Journals (Sweden)

    S. Piettre


    Full Text Available Efforts to develop synthetic methodologies allowing the preparation of α,α– difluorophosphonothioates, α,α–difluorophosphonodithioates, α,α–difluorophosphono- trithioates, and α,α–difluorophosphinates are reviewed in the light of applications in the field of modified oligonucleotides and cyclitol phosphates. Two successful approaches have been developed, based either on the addition of phosphorus-centered radicals onto gem–difluoroalkenes or on a process involving the addition of lithiodifluorophosphono- thioates 91 onto a ketone and the subsequent deoxygenation reaction of the adduct. The radical route successfully developed a practical route to α,α–difluoro–H–phosphinates which proved to be useful intermediates to a variety of phosphate isosters. The ionic route led to the first preparation of phosphonodifluoromethyl analogues of nucleoside– 3’–phosphates.

  7. Antisense oligonucleotide-mediated exon skipping as a strategy to reduce proteolytic cleavage of ataxin-3. (United States)

    Toonen, Lodewijk J A; Schmidt, Iris; Luijsterburg, Martijn S; van Attikum, Haico; van Roon-Mom, Willeke M C


    Spinocerebellar ataxia type-3 (SCA3) is a neurodegenerative disorder caused by a polyglutamine repeat expansion in the ataxin-3 protein. Cleavage of mutant ataxin-3 by proteolytic enzymes yields ataxin-3 fragments containing the polyglutamine stretch. These shorter ataxin-3 fragments are thought to be involved in SCA3 pathogenesis due to their increased cellular toxicity and their involvement in formation of the characteristic neuronal aggregates. As a strategy to prevent formation of toxic cleavage fragments, we investigated an antisense oligonucleotide-mediated modification of the ataxin-3 pre-mRNA through exon skipping of exon 8 and 9, resulting in the removal of a central 88 amino acid region of the ataxin-3 protein. This removed protein region contains several predicted cleavage sites and two ubiquitin-interacting motifs. In contrast to unmodified mutant ataxin-3, the internally truncated ataxin-3 protein did not give rise to potentially toxic cleavage fragments when incubated with caspases. In vitro experiments did not show cellular toxicity of the modified ataxin-3 protein. However, the modified protein was incapable of binding poly-ubiquitin chains, which may interfere with its normal deubiquitinating function. Low exon skipping efficiencies combined with reduction in important ataxin-3 protein functions suggest that skipping of exon 8 and 9 is not a viable therapeutic option for SCA3.

  8. Splice-correcting oligonucleotides restore BTK function in X-linked agammaglobulinemia model (United States)

    Bestas, Burcu; Moreno, Pedro M.D.; Blomberg, K. Emelie M.; Mohammad, Dara K.; Saleh, Amer F.; Sutlu, Tolga; Nordin, Joel Z.; Guterstam, Peter; Gustafsson, Manuela O.; Kharazi, Shabnam; Piątosa, Barbara; Roberts, Thomas C.; Behlke, Mark A.; Wood, Matthew J.A.; Gait, Michael J.; Lundin, Karin E.; El Andaloussi, Samir; Månsson, Robert; Berglöf, Anna; Wengel, Jesper; Smith, C.I. Edvard


    X-linked agammaglobulinemia (XLA) is an inherited immunodeficiency that results from mutations within the gene encoding Bruton’s tyrosine kinase (BTK). Many XLA-associated mutations affect splicing of BTK pre-mRNA and severely impair B cell development. Here, we assessed the potential of antisense, splice-correcting oligonucleotides (SCOs) targeting mutated BTK transcripts for treating XLA. Both the SCO structural design and chemical properties were optimized using 2′-O-methyl, locked nucleic acid, or phosphorodiamidate morpholino backbones. In order to have access to an animal model of XLA, we engineered a transgenic mouse that harbors a BAC with an authentic, mutated, splice-defective human BTK gene. BTK transgenic mice were bred onto a Btk knockout background to avoid interference of the orthologous mouse protein. Using this model, we determined that BTK-specific SCOs are able to correct aberrantly spliced BTK in B lymphocytes, including pro–B cells. Correction of BTK mRNA restored expression of functional protein, as shown both by enhanced lymphocyte survival and reestablished BTK activation upon B cell receptor stimulation. Furthermore, SCO treatment corrected splicing and restored BTK expression in primary cells from patients with XLA. Together, our data demonstrate that SCOs can restore BTK function and that BTK-targeting SCOs have potential as personalized medicine in patients with XLA. PMID:25105368

  9. [Identification of genetically modified vegetable sources in food and feed using hydrogel oligonucleotide microchip]. (United States)

    Griadunov, D A; Getman, I A; Chizhova, S I; Mikhaĭlovich, V M; Zasedatelev, A S; Romanov, G A


    A method of multiplex polymerase chain reaction (PCR) followed by the hybridization on a hydrogel oligonucleotide biochip was developed for simultaneous identification of ten different transgenic elements of plant DNA in feed and food products. The biochip contained 22 immobilized probes intended for (i) detection of plant DNA; (ii) plant species determination (soybean, maize, potato, rice); (iii) identification of transgenic elements, including 35S CaMV, 35S FMV, rice actine gene promoters, nos, 35S CaMV, ocs, pea rbcS1 gene terminators, and bar, gus, nptII marker genes. The limit of detection was 0.5% of genetically modified (GM) soybean and maize in analyzed samples. Identification of transgenic DNA in food and feed products using either the developed approach or real-time PCR led to virtually identical results. The assay can be used for selection of GM samples by screening food and feed products for subsequent quantitative determination of the GM component based on the identified transgene.

  10. Kinetic analysis of Yersinia pestis DNA adenine methyltransferase activity using a hemimethylated molecular break light oligonucleotide.

    Directory of Open Access Journals (Sweden)

    Robert J Wood

    Full Text Available BACKGROUND: DNA adenine methylation plays an important role in several critical bacterial processes including mismatch repair, the timing of DNA replication and the transcriptional control of gene expression. The dependence of bacterial virulence on DNA adenine methyltransferase (Dam has led to the proposal that selective Dam inhibitors might function as broad spectrum antibiotics. METHODOLOGY/PRINCIPAL FINDINGS: Herein we report the expression and purification of Yersinia pestis Dam and the development of a continuous fluorescence based assay for DNA adenine methyltransferase activity that is suitable for determining the kinetic parameters of the enzyme and for high throughput screening against potential Dam inhibitors. The assay utilised a hemimethylated break light oligonucleotide substrate containing a GATC methylation site. When this substrate was fully methylated by Dam, it became a substrate for the restriction enzyme DpnI, resulting in separation of fluorophore (fluorescein and quencher (dabcyl and therefore an increase in fluorescence. The assays were monitored in real time using a fluorescence microplate reader in 96 well format and were used for the kinetic characterisation of Yersinia pestis Dam, its substrates and the known Dam inhibitor, S-adenosylhomocysteine. The assay has been validated for high throughput screening, giving a Z-factor of 0.71+/-0.07 indicating that it is a sensitive assay for the identification of inhibitors. CONCLUSIONS/SIGNIFICANCE: The assay is therefore suitable for high throughput screening for inhibitors of DNA adenine methyltransferases and the kinetic characterisation of the inhibition.

  11. Sequence conversion by single strand oligonucleotide donors via non-homologous end joining in mammalian cells. (United States)

    Liu, Jia; Majumdar, Alokes; Liu, Jilan; Thompson, Lawrence H; Seidman, Michael M


    Double strand breaks (DSBs) can be repaired by homology independent nonhomologous end joining (NHEJ) pathways involving proteins such as Ku70/80, DNAPKcs, Xrcc4/Ligase 4, and the Mre11/Rad50/Nbs1 (MRN) complex. DSBs can also be repaired by homology-dependent pathways (HDR), in which the MRN and CtIP nucleases produce single strand ends that engage homologous sequences either by strand invasion or strand annealing. The entry of ends into HDR pathways underlies protocols for genomic manipulation that combine site-specific DSBs with appropriate informational donors. Most strategies utilize long duplex donors that participate by strand invasion. Work in yeast indicates that single strand oligonucleotide (SSO) donors are also active, over considerable distance, via a single strand annealing pathway. We examined the activity of SSO donors in mammalian cells at DSBs induced either by a restriction nuclease or by a targeted interstrand cross-link. SSO donors were effective immediately adjacent to the break, but activity declined sharply beyond approximately 100 nucleotides. Overexpression of the resection nuclease CtIP increased the frequency of SSO-mediated sequence modulation distal to the break site, but had no effect on the activity of an SSO donor adjacent to the break. Genetic and in vivo competition experiments showed that sequence conversion by SSOs in the immediate vicinity of the break was not by strand invasion or strand annealing pathways. Instead these donors competed for ends that would have otherwise entered NHEJ pathways.

  12. Spectroscopic and calorimetric studies on the triplex formation with oligonucleotide-ligand conjugates. (United States)

    Eick, Andrea; Riechert-Krause, Fanny; Weisz, Klaus


    Several triplex-forming 9-mer oligonucleotide (TFO) conjugates with a methyl- or methoxy-substituted 5-phenyl-6H-indolo[3,2-b]quinoline (PIQ) attached at the 5'-terminus or 3'-terminus or at an internal C5 thymine position were synthesized and tested for their ability to form and stabilize a triple helix with a double-helical DNA target employing UV melting experiments, fluorescence titrations, and isothermal titration calorimetry (ITC). A considerable thermal stabilization by up to 14 degrees C at pH 6.0 was observed for the 5'- and 3'-conjugates with little influence on the type of substituent but also for a conjugate with the ligand tethered by a short linker to the interior of the 9-mer TFO. A detailed thermodynamic characterization of the unmodified TFO and its 5'-conjugate with a methyl-substituted ligand by ITC experiments yielded a DeltaDeltaG degrees of -1.8 kcal mol(-1) at pH 6.0 for the TFO-attached PIQ-triplex interaction and also revealed a favorable entropic contribution as the major determinant for the free energy of PIQ binding in the conjugate. The pH dependence of triplex thermal stability highlights the importance of ring protonation of the triplex-bound ligand for its effective interaction and triplex stabilization near physiological conditions.

  13. Binding and NMR structural studies on indoloquinoline-oligonucleotide conjugates targeting duplex DNA. (United States)

    Eick, Andrea; Riechert-Krause, Fanny; Weisz, Klaus


    An 11-phenyl-indolo[3,2-b]quinoline (PIQ) was tethered through an aminoalkyl linker to the 5'-end of four pyrimidine oligonucleotides with T/C scrambled sequences at their two 5'-terminal positions. Binding to different double-helical DNA targets formed parallel triple helices with a PIQ-mediated stabilization that strongly depends on pH and the terminal base triad at the 5'-triplex-duplex junction. The most effective stabilization was observed with a TAT triplet at the 5'-junction under low pH conditions, pointing to a protonated ligand with a high triplex binding affinity and unfavorable charge repulsions in the case of a terminal C(+)GC triplet at the junction. The latter preference of the PIQ ligand for TAT over CGC is alleviated yet still preserved at higher pH. Intercalation of PIQ at the 5'-triplex-duplex junction as suggested by the triplex melting experiments was confirmed by homonuclear and heteronuclear NMR structural studies on a specifically isotope-labeled triplex. The NMR analysis revealed two coexisting species that only differ by a 180° rotation of the indoloquinoline within the intercalation pocket. NOE-derived molecular models indicate extensive stacking interactions of the indoloquinoline moiety with the TAT base triplet and CG base pair at the junction and a phenyl substituent that is positioned in the major groove and oriented almost perpendicular to the plane of the indoloquinoline.

  14. Analysis of mutations in oral poliovirus vaccine by hybridization with generic oligonucleotide microchips.

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    Proudnikov, D.; Kirillov, E.; Chumakov, K.; Donion, J.; Rezapkin, G.; Mirzabekov, A.; Biochip Technology Center; Engelhardt Inst. of Molecular Biology; Center for Biologics Evaluation and Research


    This paper describes use of a new technology of hybridization with a micro-array of immobilized oligonucleotides for detection and quantification of neurovirulent mutants in Oral Poliovirus Vaccine (OPV). We used a micro-array consisting of three-dimensional gel-elements containing all possible hexamers (total of 4096 probes). Hybridization of fluorescently labelled viral cDNA samples with such microchips resulted in a pattern of spots that was registered and quantified by a computer-linked CCD camera, so that the sequence of the original cDNA could be deduced. The method could reliably identify single point mutations, since each of them affected fluorescence intensity of 12 micro-array elements. Micro-array hybridization of DNA mixtures with varying contents of point mutants demonstrated that the method can detect as little as 10% of revertants in a population of vaccine virus. This new technology should be useful for quality control of live viral vaccines, as well as for other applications requiring identification and quantification of point mutations.

  15. Photophysical characterization of fluorescent metal nanoclusters sythesized using oligonucleotides, proteins and small reagent moleucles

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Hsin-chih [Los Alamos National Laboratory; Jaswinder, Sharma K [Los Alamos National Laboratory; Martinez, Jennifer S [Los Alamos National Laboratory; Werner, James H [Los Alamos National Laboratory; Yoo, Hyojong [Los Alamos National Laboratory


    The size transition from bulk metals to insulating nanoparticles and eventually to single atoms passes through the relatively unexplored few-atom nanocluster region. With climensions close to the Fermi wavelength, these nanoclusters demonstrate molecule-like properties distinct from bulk metals or atoms, such as discrete and size-tunable electronic transitions which lead to photoluminescence. Current research aims to elucidate the fundamental photophysical properties of the existing metal nanoclusters made by different means and based on different encapsulation agents. Here, we report the study of the photophysical properties, including quantum yields, lifetimes, extinction coefficients, blinking dynamics and sizes, of silver and gold nanoclusters synthesized using oligonucleotides, a protein (bovine serum albumin) and a Good's buffer molecule (MES, 2-(N-morpholino)ethanesulfonic acid) as encapsulation agents. We also investigate the change of photoluminescence under varying conditions (time, temperature and salt). Furthermore, it is demonstrated here that fluorescent metal clusters can be used as a donor in forming resonance energy transfer pairs with a commercial organic quenching dye.

  16. Analysis of Structural Flexibility of Damaged DNA Using Thiol-Tethered Oligonucleotide Duplexes.

    Directory of Open Access Journals (Sweden)

    Masashi Fujita

    Full Text Available Bent structures are formed in DNA by the binding of small molecules or proteins. We developed a chemical method to detect bent DNA structures. Oligonucleotide duplexes in which two mercaptoalkyl groups were attached to the positions facing each other across the major groove were prepared. When the duplex contained the cisplatin adduct, which was proved to induce static helix bending, interstrand disulfide bond formation under an oxygen atmosphere was detected by HPLC analyses, but not in the non-adducted duplex, when the two thiol-tethered nucleosides were separated by six base pairs. When the insert was five and seven base pairs, the disulfide bond was formed and was not formed, respectively, regardless of the cisplatin adduct formation. The same reaction was observed in the duplexes containing an abasic site analog and the (6–4 photoproduct. Compared with the cisplatin case, the disulfide bond formation was slower in these duplexes, but the reaction rate was nearly independent of the linker length. These results indicate that dynamic structural changes of the abasic site- and (6–4 photoproduct-containing duplexes could be detected by our method. It is strongly suggested that the UV-damaged DNA-binding protein, which specifically binds these duplexes and functions at the first step of global-genome nucleotide excision repair, recognizes the easily bendable nature of damaged DNA.

  17. Early changes in gene expression profiles of hepatic GVHD uncovered by oligonucleotide microarrays. (United States)

    Ichiba, Tamotsu; Teshima, Takanori; Kuick, Rork; Misek, David E; Liu, Chen; Takada, Yuichiro; Maeda, Yoshinobu; Reddy, Pavan; Williams, Debra L; Hanash, Samir M; Ferrara, James L M


    The liver, skin, and gastrointestinal tract are major target organs of acute graft-versus-host disease (GVHD), the major complication of allogeneic bone marrow transplantation (BMT). In order to gain a better understanding of acute GVHD in the liver, we compared the gene expression profiles of livers after experimental allogeneic and syngeneic BMT using oligonucleotide microarray. At 35 days after allogeneic BMT when hepatic GVHD was histologically evident, genes related to cellular effectors and acute-phase proteins were up-regulated, whereas genes largely related to metabolism and endocrine function were down-regulated. At day 7 after BMT before the development of histologic changes in the liver, interferon gamma (IFN-gamma)-inducible genes, major histocompatibility (MHC) class II molecules, and genes related to leukocyte trafficking had been up-regulated. Immunohistochemistry demonstrated that expression of IFN-gamma protein itself was increased in the spleen but not in hepatic tissue. These results suggest that the increased expression of genes associated with the attraction and activation of donor T cells induced by IFN-gamma early after BMT is important in the initiation of hepatic GVHD in this model and provide new potential molecular targets for early detection and intervention of acute GVHD.

  18. Inference of subgenomic origin of BACs in an interspecific hybrid sugarcane cultivar by overlapping oligonucleotide hybridizations. (United States)

    Kim, Changsoo; Robertson, Jon S; Paterson, Andrew H


    Sugarcane (Saccharum spp.) breeders in the early 20th century made remarkable progress in increasing yield and disease resistance by crossing Saccharum spontaneum L., a wild relative, to Saccharum officinarum L., a traditional cultivar. Modern sugarcane cultivars have approximately 71%-83% of their chromosomes originating from S. officinarum, approximately 10%-21% from S. spontaneum, and approximately 2%-13% recombinant or translocated chromosomes. In the present work, C(0)t-based cloning and sequencing (CBCS) was implemented to further explore highly repetitive DNA and to seek species-specific repeated DNA in both S. officinarum and S. spontaneum. For putatively species-specific sequences, overlappping oligonucleotide probes (overgos) were designed and hybridized to BAC filters from the interspecific hybrid sugarcane cultivar 'R570' to try to deduce parental origins of BAC clones. We inferred that 12 967 BACs putatively originated from S. officinarum and 5117 BACs from S. spontaneum. Another 1103 BACs were hybridized by both species-specific overgos, too many to account for by conventional recombination, thus suggesting ectopic recombination and (or) translocation of DNA elements. Constructing a low C(0)t library is useful to collect highly repeated DNA sequences and to search for potentially species-specific molecular markers, especially among recently diverged species. Even in the absence of repeat families that are species-specific in their entirety, the identification of localized variations within consensus sequences, coupled with the site specificity of short synthetic overgos, permits researchers to monitor species-specific or species-enriched variants.

  19. Experimental design, modeling and optimization of polyplex formation between DNA oligonucleotides and branched polyethylenimine. (United States)

    Clima, Lilia; Ursu, Elena L; Cojocaru, Corneliu; Rotaru, Alexandru; Barboiu, Mihail; Pinteala, Mariana


    The complexes formed by DNA and polycations have received great attention owing to their potential application in gene therapy. In this study, the binding efficiency between double-stranded oligonucleotides (dsDNA) and branched polyethylenimine (B-PEI) has been quantified by processing of the images captured from the gel electrophoresis assays. The central composite experimental design has been employed to investigate the effects of controllable factors on the binding efficiency. On the basis of experimental data and the response surface methodology, a multivariate regression model has been constructed and statistically validated. The model has enabled us to predict the binding efficiency depending on experimental factors, such as concentrations of dsDNA and B-PEI as well as the initial pH of solution. The optimization of the binding process has been performed using simplex and gradient methods. The optimal conditions determined for polyplex formation have yielded a maximal binding efficiency close to 100%. In order to reveal the mechanism of complex formation at the atomic-scale, a molecular dynamic simulation has been carried out. According to the computation results, B-PEI amine hydrogen atoms have interacted with oxygen atoms from dsDNA phosphate groups. These interactions have led to the formation of hydrogen bonds between macromolecules, stabilizing the polyplex structure.

  20. Translation efficiency of mRNAs is increased by antisense oligonucleotides targeting upstream open reading frames. (United States)

    Liang, Xue-Hai; Shen, Wen; Sun, Hong; Migawa, Michael T; Vickers, Timothy A; Crooke, Stanley T


    Increasing the levels of therapeutic proteins in vivo remains challenging. Antisense oligonucleotides (ASOs) are often used to downregulate gene expression or to modify RNA splicing, but antisense technology has not previously been used to directly increase the production of selected proteins. Here we used a class of modified ASOs that bind to mRNA sequences in upstream open reading frames (uORFs) to specifically increase the amounts of protein translated from a downstream primary ORF (pORF). Using ASO treatment, we increased the amount of proteins expressed from four genes by 30-150% in a dose-dependent manner in both human and mouse cells. Notably, systemic treatment of mice with ASO resulted in an ∼80% protein increase of LRPPRC. The ASO-mediated increase in protein expression was sequence-specific, occurred at the level of translation and was dependent on helicase activity. We also found that the type of RNA modification and the position of modified nucleotides in ASOs affected translation of a pORF. ASOs are a useful class of therapeutic agents with broad utility.

  1. Oligonucleotide microarray identifies genes differentially expressed during tumorigenesis of DMBA-induced pancreatic cancer in rats. (United States)

    Guo, Jun-Chao; Li, Jian; Yang, Ying-Chi; Zhou, Li; Zhang, Tai-Ping; Zhao, Yu-Pei


    The extremely dismal prognosis of pancreatic cancer (PC) is attributed, at least in part, to lack of early diagnosis. Therefore, identifying differentially expressed genes in multiple steps of tumorigenesis of PC is of great interest. In the present study, a 7,12-dimethylbenzanthraene (DMBA)-induced PC model was established in male Sprague-Dawley rats. The gene expression profile was screened using an oligonucleotide microarray, followed by real-time quantitative polymerase chain reaction (qRT-PCR) and immunohistochemical staining validation. A total of 661 differentially expressed genes were identified in stages of pancreatic carcinogenesis. According to GO classification, these genes were involved in multiple molecular pathways. Using two-way hierarchical clustering analysis, normal pancreas, acute and chronic pancreatitis, PanIN, early and advanced pancreatic cancer were completely discriminated. Furthermore, 11 upregulated and 142 downregulated genes (probes) were found by Mann-Kendall trend Monotone test, indicating homologous genes of rat and human. The qRT-PCR and immunohistochemistry analysis of CXCR7 and UBe2c, two of the identified genes, confirmed the microarray results. In human PC cell lines, knockdown of CXCR7 resulted in decreased migration and invasion. Collectively, our data identified several promising markers and therapeutic targets of PC based on a comprehensive screening and systemic validation.

  2. Recapitulation of the hairless mouse phenotype using catalytic oligonucleotides: implications for permanent hair removal. (United States)

    Cserhalmi-Friedman, Peter B; Panteleyev, Andrey A; Christiano, Angela M


    Ribozyme technology is widely used to target mRNA in a sequence-specific fashion and thus change the expression pattern of cells or tissues. While the goal of mRNA targeting is usually the cleavage of mutant mRNAs with the prospect of gene therapy for inherited diseases, in certain instances, targeting of wild-type genes can be used therapeutically. Lack of expression of the mouse hairless gene due to inherited mutations leads to the complete and irreversible loss of hair known as atrichia. We designed this study to recapitulate the hairless phenotype in a restricted manner by topical application of deoxyribozyme-targeting molecules to specifically cleave the mouse hairless mRNA. Histological samples taken from treated skin at different times demonstrated a decreased number of hair follicles, an involution of the remaining follicles, a separation of the dermal papillae, and the presence of dermal cysts, all characteristics of the hairless phenotype, but not normally present in the skin of C57Bl/6 J mice. In this study, we successfully recapitulated the hairless phenotype using topically applied target-specific catalytic oligonucleotides designed to cleave the mouse hairless mRNA. Our results demonstrate the feasibility of using ribozyme technology to alter the gene expression in the skin via topical application and provide proof of principle for the development of this strategy for permanent hair removal.

  3. Enhanced gene repair mediated by methyl-CpG-modified single-stranded oligonucleotides (United States)

    Bertoni, Carmen; Rustagi, Arjun; Rando, Thomas A.


    Gene editing mediated by oligonucleotides has been shown to induce stable single base alterations in genomic DNA in both prokaryotic and eukaryotic organisms. However, the low frequencies of gene repair have limited its applicability for both basic manipulation of genomic sequences and for the development of therapeutic approaches for genetic disorders. Here, we show that single-stranded oligodeoxynucleotides (ssODNs) containing a methyl-CpG modification and capable of binding to the methyl-CpG binding domain protein 4 (MBD4) are able to induce >10-fold higher levels of gene correction than ssODNs lacking the specific modification. Correction was stably inherited through cell division and was confirmed at the protein, transcript and genomic levels. Downregulation of MBD4 expression using RNAi prevented the enhancement of gene correction efficacy obtained using the methyl-CpG-modified ssODN, demonstrating the specificity of the repair mechanism being recruited. Our data demonstrate that efficient manipulation of genomic targets can be achieved and controlled by the type of ssODN used and by modulation of the repair mechanism involved in the correction process. This new generation of ssODNs represents an important technological advance that is likely to have an impact on multiple applications, especially for gene therapy where permanent correction of the genetic defect has clear advantages over viral and other nonviral approaches currently being tested. PMID:19854937

  4. Development of novel decoy oligonucleotides: advantages of circular dumb-bell decoy. (United States)

    Tomita, Naruya; Tomita, Tetsuya; Yuyama, Kazuhiko; Tougan, Takahiro; Tajima, Tsuyoshi; Ogihara, Toshio; Morishita, Ryuichi


    The inhibition of specific transcription regulatory proteins is a novel approach to regulate gene expression. The transcriptional activities of DNA binding proteins can be inhibited by the use of double-stranded oligonucleotides (ODNs) that compete for binding to their specific target sequences in promoters and enhancers. Transfection of this cis-element double-stranded ODN, referred to as decoy ODN, has been reported to be a powerful tool that provides a new class of anti-gene strategies to gene therapy and permits examination of specific gene regulation. We have demonstrated the usefulness of this decoy ODN strategy in animal models of restenosis, myocardial infarction, glomerulonephritis and rheumatoid arthritis. However, one of the major limitations of decoy ODN technology is the rapid degradation of phosphodiester ODNs by intracellular nucleases. To date, several different types of double-stranded decoy ODNs have been developed to overcome this issue. Circular dumb-bell (CD) double-stranded decoy ODNs that were developed to resolve this issue have attracted a high level of interest. In this review, the applications of decoy ODN strategy and the advantages of modified CD double-stranded decoy ODNs will be discussed.

  5. Establishment of a Predictive In Vitro Assay for Assessment of the Hepatotoxic Potential of Oligonucleotide Drugs.

    Directory of Open Access Journals (Sweden)

    Sabine Sewing

    Full Text Available Single stranded oligonucleotides (SSO represent a novel therapeutic modality that opens new space to address previously undruggable targets. In spite of their proven efficacy, the development of promising SSO drug candidates has been limited by reported cases of SSO-associated hepatotoxicity. The mechanisms of SSO induced liver toxicity are poorly understood, and up to now no preclinical in vitro model has been established that allows prediction of the hepatotoxicity risk of a given SSO. Therefore, preclinical assessment of hepatic liability currently relies on rodent studies that require large cohorts of animals and lengthy protocols. Here, we describe the establishment and validation of an in vitro assay using primary hepatocytes that recapitulates the hepatotoxic profile of SSOs previously observed in rodents. In vitro cytotoxicity upon unassisted delivery was measured as an increase in extracellular lactate dehydrogenase (LDH levels and concomitant reduction in intracellular glutathione and ATP levels after 3 days of treatment. Furthermore, toxic, but not safe, SSOs led to an increase in miR-122 in cell culture supernatants after 2 days of exposure, revealing the potential use of miR122 as a selective translational biomarker for detection of SSO-induced hepatotoxicity. Overall, we have developed and validated for the first time a robust in vitro screening assay for SSO liver safety profiling which allows rapid prioritization of candidate molecules early on in development.

  6. Thiolated polycarbophil as an adjuvant for permeation enhancement in nasal delivery of antisense oligonucleotides. (United States)

    Vetter, A; Martien, R; Bernkop-Schnürch, A


    The purpose of this study was to investigate the effect of thiolated polycarbophil as an adjuvant to enhance the permeation and improve the stability of a phosphorothioate antisense oligonucleotide (PTO-ODN) on the nasal mucosa. Polycarbophil-cysteine (PCP-Cys) was synthesized by the covalent attachment of L-cysteine to the polymeric backbone. Cytotoxicity tests were examined on human nasal epithelial cells from surgery of nasal polyps confirmed by histological studies. Deoxyribonuclease I activity in respiratory region of the porcine nasal cavity was analyzed by an enzymatic assay. The enzymatic degradation of PTO-ODNs on freshly excised porcine nasal mucosa was analyzed and protection of PCP-cysteine toward DNase I degradation was evaluated. Permeation studies were performed in Ussing-type diffusion chambers. PCP-Cys/GSH did not arise a remarkable mortal effect. Porcine respiratory mucosa was shown to possess nuclease activity corresponding to 0.69 Kunitz units/mL. PTO-ODNs were degraded by incubation with nasal mucosa. In the presence of 0.45% thiolated polycarbophil and 0.5% glutathione (GSH), this degradation process could be lowered. In the presence of thiolated polycarbophil and GSH the uptake of PTO-ODNs from the nasal mucosa was 1.7-fold improved. According to these results thiolated polycarbophil/GSH might be a promising excipient for nasal administration of PTO-ODNs.

  7. Nano and Microtechnologies for the Delivery of Oligonucleotides with Gene Silencing Properties

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    Giuseppe De Rosa


    Full Text Available Oligonucleotides (ONs are synthetic fragments of nucleic acid designed to modulate the expression of target proteins. DNA-based ONs (antisense, antigene, aptamer or decoy and more recently a new class of RNA-based ONs, the small interfering RNAs (siRNAs, have gained great attention for the treatment of different disease states, such as viral infections, inflammation, diabetes, and cancer. However, the development of therapeutic strategies based on ONs is hampered by their low bioavailability, poor intracellular uptake and rapid degradation in biological fluids. The use of a non-viral carrier can be a powerful tool to overcome these drawbacks. Lipid or polymer-based nanotechnologies can improve biological stability and cellular uptake of ONs, with possibility of tissue and/or cellular targeting. The use of polymeric devices can also produce a prolonged release of the ON, thus reducing the need of frequent administrations. This review summarizes advantages and issues related to the main non-viral vectors used for ON delivery.

  8. Dominant Microbial Composition and Its Vertical Distribution in Saline Meromictic Lake Kaiike (Japan) as Revealed by Quantitative Oligonucleotide Probe Membrane Hybridization


    Koizumi, Yoshikazu; Kojima, Hisaya; Fukui, Manabu


    Vertical distributions of dominant bacterial populations in saline meromictic Lake Kaiike were investigated throughout the water column and sediment by quantitative oligonucleotide probe membrane hybridization. Three oligonucleotide probes specific for the small-subunit (SSU) rRNA of three groups of Chlorobiaceae were newly designed. In addition, three general domain (Bacteria, Archaea, and Eukarya)-specific probes, two δ-Proteobacteria-specific probes, a Chlorobiaceae-specific probe, and a C...

  9. Antisense oligonucleotide to insulin—like growth factor Ⅱ induces apotosis in human ovarian cancer AO cell line

    Institute of Scientific and Technical Information of China (English)



    The effects of antisense oligonucleotide to insulin0like growth factor -Ⅱ(IGFⅡ)to induce apotosis in human ovarian cancer cells were evaluated.Antiproliferation effects of antisense to IGFⅡin ovarian cancer AO cells were determined by 3H-thymidine incorporation.Apoptosis of the IGFⅡ antisense-treated cells was quantitated by both nuclear condensation and flow cytometry after cells were stained with propidium iodide,IGFⅡ antisense(4.5μM) treatment of 48h maximally inhibited proliferation of AO cells,More than 25% of IGFⅡantisense-treated cells(4.5μM for 24h) had undergone apoptosis,whereas less than 3% of the cells were apoptotic in either IGFⅡ sense-treated cells or untreated cells.Antisense oligonucleotide to IGFⅡ significantly inhibited cell proliferation and induced apoptosis in human ovarian cancer AO cell.These data suggest that IGFII may be a potential target in treatment of ovarian cancer and antisense oligonucleotide to IGFⅡ may serve as a therapeutic approach.

  10. Analyses of point mutation repair and allelic heterogeneity generated by CRISPR/Cas9 and single-stranded DNA oligonucleotides. (United States)

    Bialk, Pawel; Sansbury, Brett; Rivera-Torres, Natalia; Bloh, Kevin; Man, Dula; Kmiec, Eric B


    The repair of a point mutation can be facilitated by combined activity of a single-stranded oligonucleotide and a CRISPR/Cas9 system. While the mechanism of action of combinatorial gene editing remains to be elucidated, the regulatory circuitry of nucleotide exchange executed by oligonucleotides alone has been largely defined. The presence of the appropriate CRISPR/Cas9 system leads to an enhancement in the frequency of gene editing directed by single-stranded DNA oligonucleotides. While CRISPR/Cas9 executes double-stranded DNA cleavage efficiently, closure of the broken chromosomes is dynamic, as varying degrees of heterogeneity of the cleavage products appear to accompany the emergence of the corrected base pair. We provide a detailed analysis of allelic variance at and surrounding the target site. In one particular case, we report sequence alteration directed by a distinct member of the same gene family. Our data suggests that single-stranded DNA molecules may influence DNA junction heterogeneity created by CRISPR/Cas9.

  11. Assembly of Designed Oligonucleotides: a useful tool in synthetic biology for creating high-quality combinatorial DNA libraries. (United States)

    Acevedo-Rocha, Carlos G; Reetz, Manfred T


    The method dubbed Assembly of Designed Oligonucleotides (ADO) is a powerful tool in synthetic biology to create combinatorial DNA libraries for gene, protein, metabolic, and genome engineering. In directed evolution of proteins, ADO benefits from using reduced amino acid alphabets for saturation mutagenesis and/or DNA shuffling, but all 20 canonical amino acids can be also used as building blocks. ADO is performed in a two-step reaction. The first involves a primer-free, polymerase cycling assembly or overlap extension PCR step using carefully designed overlapping oligonucleotides. The second step is a PCR amplification using the outer primers, resulting in a high-quality and bias-free double-stranded DNA library that can be assembled with other gene fragments and/or cloned into a suitable plasmid subsequently. The protocol can be performed in a few hours. In theory, neither the length of the DNA library nor the number of DNA changes has any limits. Furthermore, with the costs of synthetic DNA dropping every year, after an initial investment is made in the oligonucleotides, these can be exchanged for alternative ones with different sequences at any point in the process, fully exploiting the potential of creating highly diverse combinatorial libraries. In the example chosen here, we show the construction of a high-quality combinatorial ADO library targeting sixteen different codons simultaneously with nonredundant degenerate codons encoding various reduced alphabets of four amino acids along the heme region of the monooxygenase P450-BM3.

  12. Factors influencing the separation of oligonucleotides using reversed-phase/ion-exchange mixed-mode high performance liquid chromatography columns. (United States)

    Biba, Mirlinda; Jiang, Eileen; Mao, Bing; Zewge, Daniel; Foley, Joe P; Welch, Christopher J


    New mixed-mode columns consisting of reversed-phase and ion-exchange separation modes were evaluated for the analysis of short RNA oligonucleotides (∼20mers). Conventional analysis for these samples typically involves using two complementary methods: strong anion-exchange liquid chromatography (SAX-LC) for separation based on charge, and ion-pair reversed-phase liquid chromatography (IP-RPLC) for separation based on hydrophobicity. Recently introduced mixed-mode high performance liquid chromatography (HPLC) columns combine both reversed-phase and ion-exchange modes, potentially offering a simpler analysis by combining the benefits of both separation modes into a single method. Analysis of a variety of RNA oligonucleotide samples using three different mixed-mode stationary phases showed some distinct benefits for oligonucleotide separation and analysis. When using these mixed-mode columns with typical IP-RPLC mobile phase conditions, such as ammonium acetate or triethylammonium acetate as the primary ion-pair reagent, the separation was mainly based on the IP-RPLC mode. However, when changing the mobile phase conditions to those more typical for SAX-LC, such as salt gradients with NaCl or NaBr, very different separation patterns were observed due to mixed-mode interactions. In addition, the Scherzo SW-C18 and SM-C18 columns with sodium chloride or sodium bromide salt gradients also showed significant improvements in peak shape.

  13. Improved antisense oligonucleotide design to suppress aberrant SMN2 gene transcript processing: towards a treatment for spinal muscular atrophy.

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    Chalermchai Mitrpant

    Full Text Available Spinal muscular atrophy (SMA is caused by loss of the Survival Motor Neuron 1 (SMN1 gene, resulting in reduced SMN protein. Humans possess the additional SMN2 gene (or genes that does produce low level of full length SMN, but cannot adequately compensate for loss of SMN1 due to aberrant splicing. The majority of SMN2 gene transcripts lack exon 7 and the resultant SMNΔ7 mRNA is translated into an unstable and non-functional protein. Splice intervention therapies to promote exon 7 retention and increase amounts of full-length SMN2 transcript offer great potential as a treatment for SMA patients. Several splice silencing motifs in SMN2 have been identified as potential targets for antisense oligonucleotide mediated splice modification. A strong splice silencer is located downstream of exon 7 in SMN2 intron 7. Antisense oligonucleotides targeting this motif promoted SMN2 exon 7 retention in the mature SMN2 transcripts, with increased SMN expression detected in SMA fibroblasts. We report here systematic optimisation of phosphorodiamidate morpholino oligonucleotides (PMO that promote exon 7 retention to levels that rescued the phenotype in a severe mouse model of SMA after intracerebroventricular delivery. Furthermore, the PMO gives the longest survival reported to date after a single dosing by ICV.

  14. Improved Genome Editing Efficiency and Flexibility Using Modified Oligonucleotides with TALEN and CRISPR-Cas9 Nucleases

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    Jean-Baptiste Renaud


    Full Text Available Genome editing has now been reported in many systems using TALEN and CRISPR-Cas9 nucleases. Precise mutations can be introduced during homology-directed repair with donor DNA carrying the wanted sequence edit, but efficiency is usually lower than for gene knockout and optimal strategies have not been extensively investigated. Here, we show that using phosphorothioate-modified oligonucleotides strongly enhances genome editing efficiency of single-stranded oligonucleotide donors in cultured cells. In addition, it provides better design flexibility, allowing insertions more than 100 bp long. Despite previous reports of phosphorothioate-modified oligonucleotide toxicity, clones of edited cells are readily isolated and targeted sequence insertions are achieved in rats and mice with very high frequency, allowing for homozygous loxP site insertion at the mouse ROSA locus in particular. Finally, when detected, imprecise knockin events exhibit indels that are asymmetrically positioned, consistent with genome editing taking place by two steps of single-strand annealing.

  15. Experimental study of triplex-forming oligonucleotide targeted to the initiator of S gene of HBV labeled with 125Ⅰ

    Institute of Scientific and Technical Information of China (English)


    This study is used to investigate the feasibility of employing the Iodogen method to label triplex-forming oligonucleotide (TFO) targeted to the initiator of the S gene of HBV with 125Ⅰ. A 17-mer oligonucleotides sequence was synthesized and grafted at the 5' terminal with a tyramine group. Radioiodination of the tyramine-TFO with 125Ⅰwas then performed using the Iodogen method. After TFO was labeled with 125Ⅰ using the Iodogen method, the labeling rate, the radiochemical purity, stability and bioactivity were determined, respectively. The results show that the radiolabeling rate and the radiochemical purity were 93% and 99%, respectively; and the radiochemical purity is more than 90% in vitro at -20℃ on the 5th day after labeling; and the rate of 125Ⅰ-tyramine-TFO binding to HepG2.2.15cells was (37.2±1.4) % and statistically different from the rate of HepG2 (p<0.5). Hence, it is concluded that the labeling of oligonucleotides conjugated with tyramine using the Iodogen method is successful and is characterized with a high labeling rate, high stability, and a low loss of bioactivity of the labeled agent.

  16. A Targeted Oligonucleotide Enhancer of SMN2 Exon 7 Splicing Forms Competing Quadruplex and Protein Complexes in Functional Conditions

    Directory of Open Access Journals (Sweden)

    Lindsay D. Smith


    Full Text Available The use of oligonucleotides to activate the splicing of selected exons is limited by a poor understanding of the mechanisms affected. A targeted bifunctional oligonucleotide enhancer of splicing (TOES anneals to SMN2 exon 7 and carries an exonic splicing enhancer (ESE sequence. We show that it stimulates splicing specifically of intron 6 in the presence of repressing sequences in intron 7. Complementarity to the 5′ end of exon 7 increases U2AF65 binding, but the ESE sequence is required for efficient recruitment of U2 snRNP. The ESE forms at least three coexisting discrete states: a quadruplex, a complex containing only hnRNP F/H, and a complex enriched in the activator SRSF1. Neither hnRNP H nor quadruplex formation contributes to ESE activity. The results suggest that splicing limited by weak signals can be rescued by rapid exchange of TOES oligonucleotides in various complexes and raise the possibility that SR proteins associate transiently with ESEs.

  17. probeBase--an online resource for rRNA-targeted oligonucleotide probes and primers: new features 2016. (United States)

    Greuter, Daniel; Loy, Alexander; Horn, Matthias; Rattei, Thomas


    probeBase is a manually maintained and curated database of rRNA-targeted oligonucleotide probes and primers. Contextual information and multiple options for evaluating in silico hybridization performance against the most recent rRNA sequence databases are provided for each oligonucleotide entry, which makes probeBase an important and frequently used resource for microbiology research and diagnostics. Here we present a major update of probeBase, which was last featured in the NAR Database Issue 2007. This update describes a complete remodeling of the database architecture and environment to accommodate computationally efficient access. Improved search functions, sequence match tools and data output now extend the opportunities for finding suitable hierarchical probe sets that target an organism or taxon at different taxonomic levels. To facilitate the identification of complementary probe sets for organisms represented by short rRNA sequence reads generated by amplicon sequencing or metagenomic analysis with next generation sequencing technologies such as Illumina and IonTorrent, we introduce a novel tool that recovers surrogate near full-length rRNA sequences for short query sequences and finds matching oligonucleotides in probeBase.

  18. Iron Oxide Nanoparticles Coated with a Phosphorothioate Oligonucleotide and a Cationic Peptide: Exploring Four Different Ways of Surface Functionalization

    Directory of Open Access Journals (Sweden)

    Frédéric Geinguenaud


    Full Text Available The superparamagnetic iron oxide nanoparticles (SPIONs have great potential in therapeutic and diagnostic applications. Due to their superparamagnetic behavior, they are used clinically as a Magnetic Resonance Imaging (MRI contrast agent. Iron oxide nanoparticles are also recognized todays as smart drug-delivery systems. However, to increase their specificity, it is essential to functionalize them with a molecule that effectively targets a specific area of the body. Among the molecules that can fulfill this role, peptides are excellent candidates. Oligonucleotides are recognized as potential drugs for various diseases but suffer from poor uptake and intracellular degradation. In this work, we explore four different strategies, based on the electrostatic interactions between the different partners, to functionalize the surface of SPIONs with a phosphorothioate oligonucleotide (ODN and a cationic peptide labeled with a fluorophore. The internalization of the nanoparticles has been evaluated in vitro on RAW 264.7 cells. Among these strategies, the “«one-step assembly»”, i.e., the direct complexation of oligonucleotides and peptides on iron oxide nanoparticles, provides the best way of coating for the internalization of the nanocomplexes.

  19. Inhibitory effect of 2 '-o-methoxyethyl-modified antisense oligonucleotides targeting vascular endothelial growth factor A on SKOV3 human ovarian cancer cells

    Institute of Scientific and Technical Information of China (English)

    FU Yi-bing; WEN Ze-qing; ZHAO Xing-bo; YAN Lei; ZHANG Chun-hua; WANG Fei


    Background Ovarian cancers are often at an advanced stage at diagnosis because early detection is difficult. The poor prognosis of ovarian cancers highlights the crucial need to develop better therapeutic agents and strategies. The objective of this study was to investigate the inhibitory effects of a new modified antisense oligonucleotides targeting vascular endothelial growth factor A (VEGF-A) in SKOV3 ovarian cancer cells.Methods Antisense oligonucleotides targeting VEGF-A was designed, synthesized and transfected into SKOV3ovarian cancer cells. Western blotting and real-time RT-PCR were used to analyze the inhibitory effects of antisense oligonucleotides on VEGF-A protein and mRNA expression. Transwell matrix assay was used to detect cell migration inhibition.Results The antisense oligonucleotides targeting VEGF-A significantly decreased VEGF-A protein and mRNA expression and inhibited cell migration in SKOV3 ovarian cancer cells.Conclusions This new modified antisense oligonucleotides targeting VEGF-A can decrease VEGF-A expression and inhibit cell migration in SKOV3 ovarian cancer cells. This new oligonucleotides may be a promising therapeutic agent for ovarian cancers.

  20. Abundance, distribution and patch formation of zooplankton (United States)

    Paffenhöfer, Gustav-Adolf; Sherman, Byron K.; Lee, Thomas N.

    The goal of studies described here was to determine the responses of zooplankton taxa to phytoplankton patches which develop in and near intrusions of cold, nutrient-rich Gulf Stream water. To achieve this goal we determined the horizontal and vertical distributions of abundant mesozooplankton taxa on the south-eastern continental shelf of the USA between 29°30‧ and 31°N. The study period was from June 23 to August 16, 1981. Highest concentrations of zooplankton usually occurred in and near patches of phytoplankton. Increased phytoplankton appeared to trigger the formation of patches of the calanoid copepod Temora turbinata and the cyclopoid copepods Oithona spp. and Oncaea spp. The patches of zooplankton had greater alongshore than cross-shelf dimensions. T. turbinata responded rapidly to increased concentrations of phytoplankton by reproducing and aggregating in and above intruded waters. Oithonidae which were often, but not always, abundant in phytoplankton patches eventually attained high concentrations over most of the middle and part of the inner shelf. Their concentration and that of Oncaeidae increased steadily. Oncaeidae were not abundant in recently upwelled waters, as was T. turbinata but reached high concentrations in older intrusions when the abundance of T. turbinata remained level or decreased slowly. Both cyclopoid taxa are thought to reproduce slowly (egg sacs) compared to T. turbinata. Another taxon, the doliolids, became abundant far more rapidly in intruded waters (by asexual reproduction) than did the other three taxa. Doliolids were the most opportunistic intrusion zooplankton form. They do not regularly occur in low abundance on the shelf, as do the three copepod taxa, but develop in pulses in regions where T. turbinata and Oncaea are not abundant. Of the four taxa studied the abundance of doliolids increased and decreased most rapidly, whereas Oithona and Oncaea increased slowly and did not decrease during the study period. T. turbinata