Abstract:
:Scanning force microscopy was used to examine DNA condensates prepared with varying stoichiometries of lipospermine or polyethylenimine in physiological solution. For the first time, individual DNA strands were clearly visualized in incomplete condensates without drying. Using lipospermine at sub-saturating concentrations, discrete nuclei of condensation were observed often surrounded by folded loops of DNA. Similar packing of DNA loops occurred for polyethylenimine-induced condensation. Increasing the amount of the condensing agent led to the progressive coalescence or aggregation of initial condensation nuclei through folding rather than winding the DNA. At over-saturating charge ratios of the cationic lipid or polymer to DNA, condensates had sizes smaller than or equal to those measured previously in electron micrographs. Polyethylenimine condensates were more compact than lipospermine condensates and both produced more homogeneously compacted plasmids when used in a 2-4-fold charge excess. The size and morphology of the condensates may affect their efficiency in transfection.
journal_name
Nucleic Acids Resjournal_title
Nucleic acids researchauthors
Dunlap DD,Maggi A,Soria MR,Monaco Ldoi
10.1093/nar/25.15.3095subject
Has Abstractpub_date
1997-08-01 00:00:00pages
3095-101issue
15eissn
0305-1048issn
1362-4962pii
gka504journal_volume
25pub_type
杂志文章abstract::Little is known about the function of most non-coding RNAs (ncRNAs). The majority of long ncRNAs (lncRNAs) is expressed at very low levels and it is a matter of intense debate whether these can be of functional relevance. Here, we identified lncRNAs regulating the viability of lung cancer cells in a high-throughput RN...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gkx076
更新日期:2017-05-19 00:00:00
abstract::A gene encoding a putative DNA helicase from Staphylococcus aureus USA300 was cloned and expressed in Escherichia coli. The protein was purified to over 90% purity by chromatography. The purified enzyme, SauUSI, predominantly cleaves modified DNA containing 5mC and 5-hydroxymethylcytosine. Cleavage of 5mC-modified pla...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gkr098
更新日期:2011-07-01 00:00:00
abstract::Antisense oligodeoxynucleotides targeted to Ha-ras mRNA have been designed to discriminate between the codon 12-mutated oncogene and the normal proto-oncogene. An in vitro assay using two different sources of RNase H (rabbit reticulocyte lysates and nuclear extract from HeLa cells) was used to characterize oligonucleo...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/23.17.3411
更新日期:1995-09-11 00:00:00
abstract::Transcription of the human adenovirus 5 genome in transformed rat embryo cells (DFK3) was investigated using two different approaches. Preferential digestion of transcribed viral sequences by DNase I was analysed using kinetics of renaturation of 32P-labeled Ad5 HpaI restriction fragments in the presence of material w...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/5.1.1
更新日期:1978-01-01 00:00:00
abstract::The helical twist of poly d(A-s4T) was determined from the periodicity of the cleavage patterns of the double stranded polydeoxynucleotide adsorbed on calcium phosphate and found to be 14 bp per turn. Both cleavage patterns and 31P NMR spectra indicate a mononucleotide structure rather than an alternating B DNA like p...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/14.5.2241
更新日期:1986-03-11 00:00:00
abstract::Chicken-erythrocyte inner histone tetramer has been complexed with several natural and synthetic DNA duplexes by salt-gradient dialysis at various protein/DNA ratios. The resulting complexes, in low-ionic-strength buffer, have been examined by electron microscopy, circular dichroism, and thermal denaturation. Electron...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/5.10.3603
更新日期:1978-10-01 00:00:00
abstract::The side chains of the 20 types of amino acids, owing to a large extent to their different physical properties, have characteristic distributions in interior/surface regions of individual proteins and in interface/non-interface portions of protein surfaces that bind proteins or nucleic acids. These distributions have ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gkm231
更新日期:2007-07-01 00:00:00
abstract::Gramene (http://www.gramene.org) is a knowledgebase for comparative functional analysis in major crops and model plant species. The current release, #54, includes over 1.7 million genes from 44 reference genomes, most of which were organized into 62,367 gene families through orthologous and paralogous gene classificat...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gkx1111
更新日期:2018-01-04 00:00:00
abstract::We have recently described three group I introns inserted into a single gene, orf142, of the staphylococcal bacteriophage Twort and suggested the presence of at least two additional self-splicing introns in this phage genome. Here we report that two previously uncharacterized introns, 429 and 1087 nt in length, interr...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/30.9.1935
更新日期:2002-05-01 00:00:00
abstract::We have sequenced the 480 base pair (bp) repeating unit of the 5S RNA genes of the Dipteran fly Calliphora erythrocephala and compared this sequence to the three known 5S RNA gene sequences from the Dipteran Genus Drosophila (1,2). A striking series of five perfectly conserved homologies identically positioned within ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/12.21.8193
更新日期:1984-11-12 00:00:00
abstract::Mariner transposition is a complex reaction that involves three recombination sites and six strand breaking and joining reactions. This requires precise spatial and temporal coordination between the different components to ensure a productive outcome and minimize genomic instability. We have investigated how the cleav...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gku172
更新日期:2014-05-01 00:00:00
abstract::MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression post-transcriptionally. Previous studies, which characterized miRNA function, revealed their involvement in fundamental biological processes. Importantly, miRNA expression is deregulated in many human diseases. Specific inhibition of miRNAs usin...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gkt823
更新日期:2013-12-01 00:00:00
abstract::50 to 55% of tobacco and barley nuclear DNA is accessible to micrococcal endonuclease digestion. The DNA fragments resulting from a mild endonuclease treatment are multiples of a basic unit of 194 +/- 6 base pairs in tobacco and 195 +/- 6 base pairs in barley. After extensive digestion, a DNA fragment of approximately...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/4.10.3617
更新日期:1977-10-01 00:00:00
abstract::Oligodeoxyribonucleotides incorporating non-hydrolyzable dialkyl sulfide linked thymidine dimers (TsT) were synthesized chemically by the solid-phase approach. The sulfide dimer TsT was stable to degradation by snake-venom phosphodiesterase, calf spleen phosphodiesterase, Nuclease P1 and Nuclease S1. Thermal denaturat...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/21.6.1473
更新日期:1993-03-25 00:00:00
abstract::Histone variants play an important role in shaping the mammalian epigenome and their aberrant expression is frequently observed in several types of cancer. However, the mechanisms that mediate their function and the composition of the variant-containing chromatin are still largely unknown. A proteomic interrogation of...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gku303
更新日期:2014-06-01 00:00:00
abstract::A cDNA library was constructed from the mRNA of the Ig lambda producing Burkitt's lymphoma cell line, EB4. Overlapping clones encompassing the coding sequence of the Ig lambda mRNA were isolated and sequenced. The predicted amino acid sequence shows a short hydrophobic leader peptide and a mature polypeptide of 217 re...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/13.8.2931
更新日期:1985-04-25 00:00:00
abstract::The heterogeneous nuclear ribonucleoprotein (hnRNP) A2 is a multi-tasking protein that acts in the cytoplasm and nucleus. We have explored the possibility that this protein is associated with telomeres and participates in their maintenance. Rat brain hnRNP A2 was shown to have two nucleic acid binding sites. In the pr...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gki203
更新日期:2005-01-19 00:00:00
abstract::Chromatin distribution is not uniform along the human genome. In most genes there is a promoter-associated nucleosome free region (NFR) followed by an array of nucleosomes towards the gene body in which the first (+1) nucleosome is strongly positioned. The function of this characteristic chromatin distribution in tran...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gkv149
更新日期:2015-03-31 00:00:00
abstract::Sequencing by hybridization (SBH) approaches to DNA sequencing face two conflicting constraints. First, in order to ensure that the target DNA binds reliably, the oligonucleotide probes that are attached to the chip array must be >15 bp in length. Secondly, the total number of possible 15 bp oligonucleotides is too la...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gkh210
更新日期:2004-02-18 00:00:00
abstract::This laboratory has established in previous studies that Pmel 17, a gene expressed specifically in melanocytes, maps near the silver coat color locus (si/si) on mouse chromosome 10. In the current study, we have focused on determining whether or not the si allele carries a mutation in Pmel 17. Pmel 17 cDNA clones, iso...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/23.1.154
更新日期:1995-01-11 00:00:00
abstract::Studies involving ribozyme-directed inactivation of targeted RNA molecules have met with mixed success, making clear the importance of methods to measure and optimize ribozyme activity within cells. The interpretation of biochemical assays for determining ribozyme activity in the cellular environment have been complic...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/26.15.3494
更新日期:1998-08-01 00:00:00
abstract::Emerging evidence suggests that recombinant adeno-associated viral (rAAV) vectors can be used for specific gene targeting in human somatic cells. We have developed an rAAV vector construction procedure employing fusion PCR and a single cloning step that considerably simplifies the knockout process. We demonstrate its ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gnh009
更新日期:2004-01-02 00:00:00
abstract::We cloned and sequenced a portion of chloroplast DNA from the hornwort Anthoceros formosae. A nucleotide sequence of 7556 bp contained structures similar to those of ndhK, ndhC, trnV, trnM, atpE, atpB, rbcL, trnR and accD. The arrangement of these was the same as that of other chloroplast DNA. However, two nonsense co...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/24.6.1008
更新日期:1996-03-15 00:00:00
abstract::We have studied the ability of the wt1 tumor suppressor gene product to repress different classes of activation domains previously shown to stimulate the initiation and elongation steps of RNA polymerase II transcription in vivo. Repression assays revealed that WT1 represses all three classes of activation domains: Sp...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/27.14.2889
更新日期:1999-07-15 00:00:00
abstract::The DNA sequence of a 354 basepair EcoRI-HindIII fragment of plasmid pMB9 which has originally been derived from plasmid pSC101 has been resolved. This fragment contains a promoter for transcription directed towards the EcoRI site. Escherichia coli RNA polymerase binds to a region within the EcoRI-HindIII fragment whi...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/8.7.1535
更新日期:1980-04-11 00:00:00
abstract::Bisulfite genomic sequencing is the most widely used technique to analyze the 5-methylation of cytosines, the prevalent covalent DNA modification in mammals. The process is based on the selective transformation of unmethylated cytosines to uridines. Then, the investigated genomic regions are PCR amplified, subcloned a...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/gni012
更新日期:2005-01-13 00:00:00
abstract::Inosine was prepared (15% yield) by treatment of 5-amino-1-beta-D-ribofuranosyl-4-imidazolecarboxamide (AICA-riboside) with chloroform in the presence of sodium methoxide. This ring closure can be reasonably explained by assuming the formation of dichlorocarbene from chloroform and alkali. Carbon tetrachloride or hexa...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/3.1.231
更新日期:1976-01-01 00:00:00
abstract::The replication origin (oriC) of the Escherichia coli chromosome has been cloned and the region essential for chromosomal replication has been delimited to 245 base pairs. In previous studies the ability of recombinants between oriC and ColE1-type vectors, to transform E. coli polA- strains was used to determine which...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/11.22.8007
更新日期:1983-11-25 00:00:00
abstract::Not I linking clones contain sequences flanking Not I recognition sites and were previously shown to be tightly associated with CpG islands and genes. To directly assess the value of Not I clones in genome research, high density grids with 50 000 Not I linking clones originating from six representative Not I linking l...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/28.7.1635
更新日期:2000-04-01 00:00:00
abstract::Details of polynucleotide flexibility may be probed through a combination of semiempirical potential energy calculations and statistical mechanical analyses. The pseudorotational motions of the furanose and the long-range correlated rotations of the chain backbone are described briefly here. ...
journal_title:Nucleic acids research
pub_type: 杂志文章
doi:10.1093/nar/10.3.777
更新日期:1982-02-11 00:00:00