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Beaudier P, Zein SA, Chatzipapas K, Ngoc Tran H, Devès G, Plawinski L, Liénard R, Dupuy D, Barberet P, Incerti S, Gobet F, Seznec H. Quantitative analysis of dose dependent DNA fragmentation in dry pBR322 plasmid using long read sequencing and Monte Carlo simulations. Sci Rep 2024; 14:18650. [PMID: 39134627 PMCID: PMC11319478 DOI: 10.1038/s41598-024-69406-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 08/05/2024] [Indexed: 08/15/2024] Open
Abstract
Exposure to ionizing radiation can induce genetic aberrations via unrepaired DNA strand breaks. To investigate quantitatively the dose-effect relationship at the molecular level, we irradiated dry pBR322 plasmid DNA with 3 MeV protons and assessed fragmentation yields at different radiation doses using long-read sequencing from Oxford Nanopore Technologies. This technology applied to a reference DNA model revealed dose-dependent fragmentation, as evidenced by read length distributions, showing no discernible radiation sensitivity in specific genetic sequences. In addition, we propose a method for directly measuring the single-strand break (SSB) yield. Furthermore, through a comparative study with a collection of previous works on dry DNA irradiation, we show that the irradiation protocol leads to biases in the definition of ionizing sources. We support this scenario by discussing the size distributions of nanopore sequencing reads in the light of Geant4 and Geant4-DNA simulation toolkit predictions. We show that integrating long-read sequencing technologies with advanced Monte Carlo simulations paves a promising path toward advancing our comprehension and prediction of radiation-induced DNA fragmentation.
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Affiliation(s)
- Pierre Beaudier
- CNRS, LP2iB, UMR 5797, Univ. Bordeaux, 33170, Gradignan, France
- CNRS, INSERM, ARNA, UMR5320, U1212, Univ. Bordeaux, 33000, Bordeaux, France
| | - Sara A Zein
- CNRS, LP2iB, UMR 5797, Univ. Bordeaux, 33170, Gradignan, France
| | | | - Hoang Ngoc Tran
- CNRS, LP2iB, UMR 5797, Univ. Bordeaux, 33170, Gradignan, France
| | - Guillaume Devès
- CNRS, LP2iB, UMR 5797, Univ. Bordeaux, 33170, Gradignan, France
| | | | - Rémy Liénard
- CNRS, LP2iB, UMR 5797, Univ. Bordeaux, 33170, Gradignan, France
| | - Denis Dupuy
- CNRS, INSERM, ARNA, UMR5320, U1212, Univ. Bordeaux, 33000, Bordeaux, France
| | | | | | - Franck Gobet
- CNRS, LP2iB, UMR 5797, Univ. Bordeaux, 33170, Gradignan, France
| | - Hervé Seznec
- CNRS, LP2iB, UMR 5797, Univ. Bordeaux, 33170, Gradignan, France.
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2
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Mohammad N, Talton L, Dalgan S, Hetzler Z, Steksova A, Wei Q. Ratiometric nonfluorescent CRISPR assay utilizing Cas12a-induced plasmid supercoil relaxation. Commun Chem 2024; 7:130. [PMID: 38851849 PMCID: PMC11162422 DOI: 10.1038/s42004-024-01214-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/30/2024] [Indexed: 06/10/2024] Open
Abstract
Most CRISPR-based biosensors rely on labeled reporter molecules and expensive equipment for signal readout. A recent approach quantifies analyte concentration by sizing λ DNA reporters via gel electrophoresis, providing a simple solution for label-free detection. Here, we report an alternative strategy for label-free CRISPR-Cas12a, which relies on Cas12a trans-nicking induced supercoil relaxation of dsDNA plasmid reporters to generate a robust and ratiometric readout. The ratiometric CRISPR (rCRISPR) measures the relative percentage of supercoiled plasmid DNA to the relaxed circular DNA by gel electrophoresis for more accurate target concentration quantification. This simple method is two orders of magnitude more sensitive than the typical fluorescent reporter. This self-referenced strategy solves the potential application limitations of previously demonstrated DNA sizing-based CRISPR-Dx without compromising the sensitivity. Finally, we demonstrated the applicability of rCRISPR for detecting various model DNA targets such as HPV 16 and real AAV samples, highlighting its feasibility for point-of-care CRISPR-Dx applications.
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Affiliation(s)
- Noor Mohammad
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Chemical Engineering, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh
| | - Logan Talton
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Selen Dalgan
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Zach Hetzler
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Anastasiia Steksova
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Qingshan Wei
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
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3
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Molecular Typing of Klebsiella pneumoniae Isolated from Medical Centers in Kermanshah Using Pulse Field Gel Electrophoresis. ARCHIVES OF PEDIATRIC INFECTIOUS DISEASES 2019. [DOI: 10.5812/pedinfect.84331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Akya A, Elahi A, Chegenelorestani R, Rezaee M. Dissemination of Multidrug-Resistant, Class I and II Integrons and Molecular Typing of CTX-M-producing Klebsiella pneumoniae. Int J Appl Basic Med Res 2018; 8:100-105. [PMID: 29744322 PMCID: PMC5932916 DOI: 10.4103/ijabmr.ijabmr_333_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Introduction Klebsiella pneumoniae (K. pneumoniae) is an important opportunistic pathogen causes serious community and hospital-acquired infections, which is highly resistant to antibiotics. We aimed to determine the frequency of multidrug resistant (MDR) and molecular typing of clinical isolates of K. pneumoniae. Methodology One hundred isolates of K. pneumoniae were collected from clinical samples in three general hospitals in Kermanshah. The antimicrobial susceptibility and extended-spectrum beta-lactamases (ESBL) production of isolates were determined using disk diffusion and combined disk methods, respectively. The blaCTX-M gene, class I and II integrons were detected using polymerase chain reaction. The blaCTX-M positive isolates were selected for genotyping using pulsed-field gel electrophoresis (PFGE). Results MDR phenotype was observed in 56% of isolates. The 40% of isolates were ESBL positive and 35 isolates contained blaCTX-M. Class I and II of integrons were detected in 50 (89.2%) and 39 (69.6%) of MDR isolates, respectively. PFGE patterns of K. pneumoniaeblaCTX-M positive isolates indicated 19 clusters (X1-19) with different genotype patterns. Conclusions The study findings highlight the concern of circulating MDR strains of K. pneumoniae with blaCTX-M and class I and II integrons in Kermanshah hospitals. The presence of integrons among isolates may facilitate the spread of new resistance genes in this bacterium. Therefore, surveillance for the spread of MDR strains of this bacterium is recommended in hospitals.
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Affiliation(s)
- Alisha Akya
- Department of Medical Microbiology, Nosocomial Infection Research Centre, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Azam Elahi
- Nosocomial Infection Research Centre, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Roya Chegenelorestani
- Nosocomial Infection Research Centre, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mahya Rezaee
- Nosocomial Infection Research Centre, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Park MO, Ikenaga H, Watanabe K. Phage diversity in a methanogenic digester. MICROBIAL ECOLOGY 2007; 53:98-103. [PMID: 17186158 DOI: 10.1007/s00248-006-9053-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Accepted: 03/26/2005] [Indexed: 05/13/2023]
Abstract
It has been shown that phages are present in natural and engineered ecosystems and influence the structure and performance of prokaryotic communities. However, little has been known about phages occurring in anaerobic ecosystems, including those in methanogenic digesters for waste treatment. This study investigated phages produced in an upflow anaerobic sludge blanket methanogenic digester treating brewery wastes. Phage-like particles (PLPs) in the influent and effluent of the digester were concentrated and purified by sequential filtration and quantified and characterized by transmission electron microscopy (TEM), fluorescence assay, and field inversion gel electrophoresis (FIGE). Results indicate that numbers of PLPs in the effluent of the digester exceeded 1 x 10(9) L-1 and at least 10 times greater than those in the influent, suggesting that substantial amounts of PLPs were produced in the digester. A production rate of the PLPs was estimated at least 5.2 x 10(7) PLPs day-1 L-1. TEM and FIGE showed that a variety of phages were produced in the digester, including those affiliated with Siphoviridae, Myoviridae, and Cystoviridae.
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Affiliation(s)
- M-O Park
- Laboratory of Applied Microbiology, Marine Biotechnology Institute, Kamaishi, Iwate, 026-0001, Japan
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6
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Xiao M, Phong A, Ha C, Chan TF, Cai D, Leung L, Wan E, Kistler AL, DeRisi JL, Selvin PR, Kwok PY. Rapid DNA mapping by fluorescent single molecule detection. Nucleic Acids Res 2006; 35:e16. [PMID: 17175538 PMCID: PMC1807959 DOI: 10.1093/nar/gkl1044] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
DNA mapping is an important analytical tool in genomic sequencing, medical diagnostics and pathogen identification. Here we report an optical DNA mapping strategy based on direct imaging of individual DNA molecules and localization of multiple sequence motifs on the molecules. Individual genomic DNA molecules were labeled with fluorescent dyes at specific sequence motifs by the action of nicking endonuclease followed by the incorporation of dye terminators with DNA polymerase. The labeled DNA molecules were then stretched into linear form on a modified glass surface and imaged using total internal reflection fluorescence (TIRF) microscopy. By determining the positions of the fluorescent labels with respect to the DNA backbone, the distribution of the sequence motif recognized by the nicking endonuclease can be established with good accuracy, in a manner similar to reading a barcode. With this approach, we constructed a specific sequence motif map of lambda-DNA. We further demonstrated the capability of this approach to rapidly type a human adenovirus and several strains of human rhinovirus.
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Affiliation(s)
- Ming Xiao
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
- To whom correspondence should be addressed at: 513, Parnassus Avenue, HSW-901A, San Francisco, CA 94143, USA. Tel: +1 41 551 43876; Fax: +1 41 547 62956;
| | - Angie Phong
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Connie Ha
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Ting-Fung Chan
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Dongmei Cai
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Lucinda Leung
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Eunice Wan
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Amy L. Kistler
- Department of Biochemistry and Biophysics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Joseph L. DeRisi
- Department of Biochemistry and Biophysics, University of CaliforniaSan Francisco, CA 94115, USA
| | - Paul R. Selvin
- Department of Physics and Center of Biophysics, University of Illinois at Urbana-ChampaignUrbana, IL 61801, USA
| | - Pui-Yan Kwok
- Cardiovascular Research Institute and Center for Human Genetics, University of CaliforniaSan Francisco, CA 94115, USA
- Department of Dermatology, University of CaliforniaSan Francisco, CA 94115, USA
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7
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Lukácsi G, Takó M, Nyilasi I. Pulsed-field gel electrophoresis: a versatile tool for analysis of fungal genomes. A review. Acta Microbiol Immunol Hung 2006; 53:95-104. [PMID: 16696553 DOI: 10.1556/amicr.53.2006.1.7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The separation of chromosome-size DNA molecules by pulsed-field gel electrophoresis (PFGE) has become a well-established technique in recent years. Although it has very wide-ranging applications, it made a real breakthrough for fungal genome analysis. Because of the small size of fungal chromosomes, their investigation was not possible earlier. Different PFGE approaches allowed the separation of DNA molecules larger than 10 megabase pairs in size, and electrophoretic karyotypes for numerous previously genetically uncharacterized fungal species could be established. This review discusses the applicability of these electrophoretic karyotypes for the investigation of genome structure, for strain identification and for species delimitation.
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Affiliation(s)
- Gyöngyi Lukácsi
- Department of Microbiology, Faculty of Sciences, University of Szeged, P.O. Box 533, H-6701 Szeged, Hungary.
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Iiguni Y, Watarai H. New principle of electromagnetophoretic adsorption–desorption microchromatography. J Chromatogr A 2005; 1073:93-8. [PMID: 15909510 DOI: 10.1016/j.chroma.2004.10.059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A new principle for the chromatographic micro-separation of micrometer-sized particles in liquid has been invented by switching the electromagnetophoretic force in a capillary flow system. The principle is the combination of the Stokes force by the bulk flow and the adsorption-desorption force on a capillary inner surface controlled by an electromagnetophoretic buoyancy generated by an alternative current and a homogenous magnetic field. The observed retention profiles of test micro-particles was explained by the "zigzag" migration model mainly depended on particle size and their adsorption force to the capillary wall. By this method, we could succeed to separate polystyrene particles of 10 microm and 20 microm in diameter dispersed in 1 M KCl solution containing 0.01% Triton X-100 using only 1 mm long fused-silica capillary under 10T.
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Affiliation(s)
- Yoshinori Iiguni
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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9
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Abstract
Instrumental advances have allowed the continuous observation of single-molecule trajectories in free solution. Diffraction-limited spectral resolution at video frame rates is routinely achieved by using commercial, intensified, charge-coupled device cameras, low-power continuous-wave lasers, and standard optical microscopes. Either the native fluorescence from large biomolecules or emission from conjugated fluorescence labels can be employed to follow multiple molecules over many seconds. Both molecular motion at the liquid/solid interface and in bulk solution can be recorded. The former reveals adsorption and desorption probabilities that are related to chromatographic retention processes and to the applicability of biocompatible materials. The latter allows the manipulation of particles and large biomolecules to facilitate separation and identification.
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Affiliation(s)
- Edward S Yeung
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
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10
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Sun LV, Riegler M, O'Neill SL. Development of a physical and genetic map of the virulent Wolbachia strain wMelPop. J Bacteriol 2004; 185:7077-84. [PMID: 14645266 PMCID: PMC296261 DOI: 10.1128/jb.185.24.7077-7084.2003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report here the construction of a physical and genetic map of the virulent Wolbachia strain, wMelPop. This map was determined by ordering 28 chromosome fragments that resulted from digestion with the restriction endonucleases FseI, ApaI, SmaI, and AscI and were resolved by pulsed-field gel electrophoresis. Southern hybridization was done with 53 Wolbachia-specific genes as probes in order to determine the relative positions of these restriction fragments and use them to serve as markers. Comparison of the resulting map with the whole genome sequence of the closely related benign Wolbachia strain, wMel, shows that the two genomes are largely conserved in gene organization with the exception of a single inversion in the chromosome.
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Affiliation(s)
- Ling V Sun
- Section of Vector Biology, Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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11
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Zheng J, Yeung ES. Mechanism for the Separation of Large Molecules Based on Radial Migration in Capillary Electrophoresis. Anal Chem 2003; 75:3675-80. [PMID: 14572029 DOI: 10.1021/ac034430u] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We demonstrate a novel separation mechanism for large molecules based on their radial migration in capillary electrophoresis with applied hydrodynamic flow (HDF). The direction of radial migration depends on the direction of the applied HDF relative to the electric field. The radial migration velocities are size-dependent, which could be attributed to the different degree of deformation under shear flow. Analytical separation was demonstrated on a sample plug containing lambda DNA (48 502 bp) and phiX174 RF DNA (5386 bp) with baseline separation. Alternatively, this separation mode can be performed continuously and is thus applicable to preparative separations. Without the need for gel/polymer or complex instrumentation, this separation technique is complementary to capillary gel electrophoresis and field-flow fractionation. Although large DNA molecules were used to demonstrate the separation mechanism here, these protocols could also be applied to the separation of proteins, cells, or particles based on size, shape, or deformability.
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Affiliation(s)
- Jinjian Zheng
- Ames Laboratory--USDOE, Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
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Murakami P, Pungor E, Files J, Do L, van Rijnsoever R, Vogels R, Bout A, McCaman M. A single short stretch of homology between adenoviral vector and packaging cell line can give rise to cytopathic effect-inducing, helper-dependent E1-positive particles. Hum Gene Ther 2002; 13:909-20. [PMID: 12031124 DOI: 10.1089/10430340252939023] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
An undesirable byproduct from recombinant adenoviral vectors is the emergence of replication competent adenovirus (RCA) that result from rare homologous recombination events between the viral E1-containing (permissive) mammalian host cell genome and the virus itself, restoring the E1 gene to the viral genome. To reduce or eliminate the problem of RCA, we evaluated production of a first generation Ad5 vector (Ad5FGF4) in the cell line PER.C6. This E1-transformed human cell line contains only Ad5 nucleotides 459-3510, which precludes double crossover-type homologous recombination because the Ad5FGF-4 only contains 5' Ad5 sequence up to nucleotide 453. The Ad5FGF4 vector does, however, retain 177 nucleotides of the 3' end of the E1B-55K gene that are also present in PER.C6. With only this single region of homology between vector and cell line, we were surprised to detect virus-specific cytopathic effects (CPE) in our cell-based assay for RCA. This CPE-inducing agent was amplified in nonpermissive A549 cells but also supported amplification of the parental Ad5FGF-4. Because we were unable to isolate the CPE-inducing agent in pure form we first identified it as atypical RCA. Polymerase chain reaction (PCR) and Southern blot experiments identified viral DNA segments in which recombination had occurred between the 177 nucleotides of E1B present in both Ad5FGF-4 and PER.C6. The atypical RCA genomes contain a copy of the original (PGK promoter-E1 gene carrying) plasmid used in the construction of the PER.C6 cell line and they retained the parental FGF-4 transgene. However, significant deletions occurred within the recombined genomes in compensation for the large insertion from PER.C6 sequences and resulted in the loss of essential viral genes. This deletion renders these recombinant viruses replication defective, requiring helper functions from remaining parental Ad5FGF-4 for amplification. These atypical RCA entities may be more properly designated as helper-dependent E1-positive particles (HDEPs). This finding shows the importance of avoiding the use of "nonmatched" vectors where any overlap exists between the recombinant vector and E1 sequences in the packaging cell line. The cloning of the FGF-4 transgene into an adenoviral vector specifically "matched" for PER.C6 (lacking the 177 nucleotide region of homology) has allowed extensive virus propagation (Ad5.1FGF-4) with no CPE- or HDEP-like events yet detected.
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Affiliation(s)
- Pete Murakami
- Berlex Biosciences, Process Development Department, Richmond, CA 94804, USA
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13
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Sun LV, Foster JM, Tzertzinis G, Ono M, Bandi C, Slatko BE, O'Neill SL. Determination of Wolbachia genome size by pulsed-field gel electrophoresis. J Bacteriol 2001; 183:2219-25. [PMID: 11244060 PMCID: PMC95127 DOI: 10.1128/jb.183.7.2219-2225.2001] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2000] [Accepted: 01/08/2001] [Indexed: 11/20/2022] Open
Abstract
Genome sizes of six different Wolbachia strains from insect and nematode hosts have been determined by pulsed-field gel electrophoresis of purified DNA both before and after digestion with rare-cutting restriction endonucleases. Enzymes SmaI, ApaI, AscI, and FseI cleaved the studied Wolbachia strains at a small number of sites and were used for the determination of the genome sizes of wMelPop, wMel, and wMelCS (each 1.36 Mb), wRi (1.66 Mb), wBma (1.1 Mb), and wDim (0.95 Mb). The Wolbachia genomes studied were all much smaller than the genomes of free-living bacteria such as Escherichia coli (4.7 Mb), as is typical for obligate intracellular bacteria. There was considerable genome size variability among Wolbachia strains, especially between the more parasitic A group Wolbachia infections of insects and the mutualistic C and D group infections of nematodes. The studies described here found no evidence for extrachromosomal plasmid DNA in any of the strains examined. They also indicated that the Wolbachia genome is circular.
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Affiliation(s)
- L V Sun
- Section of Vector Biology, Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Notaro R, Cimmino A, Tabarini D, Rotoli B, Luzzatto L. In vivo telomere dynamics of human hematopoietic stem cells. Proc Natl Acad Sci U S A 1997; 94:13782-5. [PMID: 9391104 PMCID: PMC28384 DOI: 10.1073/pnas.94.25.13782] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Aging in vivo and cell division in vitro are associated with telomere shortening. Several lines of evidence suggest that telomere length may be a good predictor of the long term replicative capacity of cells. To investigate the natural fate of chromosome telomeres of hematopoietic stem cells in vivo, we measured the telomere length of peripheral blood granulocytes from 11 fully engrafted bone marrow transplant recipients and from their respective donors. In 10 of 11 donor-recipient pairs, the telomere length was significantly reduced in the recipient and the extent of reduction correlated inversely with the number of nucleated cells infused. These data provide internally controlled in vivo evidence that, concomitantly with their proliferation, hematopoietic stem cells lose telomere length; it is possible that, as a result, their proliferative potential is reduced. These findings must be taken into account when developing new protocols in which few stem cells are used for bone marrow transplantation or for gene therapy.
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Affiliation(s)
- R Notaro
- Department of Human Genetics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA
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15
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Mouradian S, Skogen JW, Dorman FD, Zarrin F, Kaufman SL, Smith LM. DNA analysis using an electrospray scanning mobility particle sizer. Anal Chem 1997; 69:919-25. [PMID: 9068276 DOI: 10.1021/ac960785k] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A scanning mobility particle sizer (SMPS) allows size separation of gas phase particles according to their electrophoretic mobilities. The addition of an electrospray source (ES) recently allowed extension of SMPS analysis to the macromolecular range. We demonstrate here the application of ES-SMPS to nucleic acids analysis. Single- and double-stranded DNA molecules ranging from 6.1 kDa (single-stranded DNA 20 nucleotides in length) to 300 kDa (500 base-pair double-stranded DNA) were separated and detected by ES-SMPS at the picomole to femtomole levels. The measured electrophoretic mobility diameters were found to correlate with the analytes' molecular weights, while the peak areas could yield quantitative information. No fragmentation of DNA was observed under the conditions employed. Different apparent densities were observed for single-stranded and double-stranded DNAs, showing a different behavior for each type of biomolecule. The total analysis time was about 3 min/spectrum. Further optimization of ES-SMPS is expected to make it a fast and sensitive technique for biopolymer characterization.
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Affiliation(s)
- S Mouradian
- Department of Chemistry, University of Wisconsin, Madison 53706-1396, USA
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16
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Linder CY, Elkahloun AG, Bittner M, Trent JM, Meltzer PS. Restriction mapping of recombinant cosmid clones using lambda terminase and field inversion gel electrophoresis. Anal Biochem 1997; 245:105-7. [PMID: 9025976 DOI: 10.1006/abio.1996.9956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- C Y Linder
- Laboratory of Cancer Genetics, National Center for Human Genome Research, National Institutes of Health, Bethesda, Maryland 20892, USA
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17
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Golub TR, Goga A, Barker GF, Afar DE, McLaughlin J, Bohlander SK, Rowley JD, Witte ON, Gilliland DG. Oligomerization of the ABL tyrosine kinase by the Ets protein TEL in human leukemia. Mol Cell Biol 1996; 16:4107-16. [PMID: 8754809 PMCID: PMC231407 DOI: 10.1128/mcb.16.8.4107] [Citation(s) in RCA: 269] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
TEL is a member of the Ets family of transcription factors which are frequently rearranged in human leukemia. The mechanism of TEL-mediated transformation, however, is unknown. We report the cloning and characterization of a chromosomal translocation associated with acute myeloid leukemia which fuses TEL to the ABL tyrosine kinase. The TEL-ABL fusion confers growth factor-independent growth to the marine hematopoietic cell line Ba/F3 and transforms Rat-1 fibroblasts and primary murine bone marrow cells. TEL-ABL is constitutively tyrosine phosphorylated and localizes to the cytoskeleton. A TEL-ABL mutant containing an ABL kinase-inactivating mutation is not constitutively phosphorylated and is nontransforming but retains cytoskeletal localization. However, constitutive phosphorylation, cytoskeletal localization, and transformation are all dependent upon a highly conserved region of TEL termed the helix-loop-helix (HLH) domain. TEL-ABL formed HLH-dependent homo-oligomers in vitro, a process critical for tyrosine kinase activation. These experiments suggest that oligomerization of TEL-ABL mediated by the TEL HLH domain is required for tyrosine kinase activation, cytoskeletal localization, and transformation. These data also suggest that oligomerization of Ets proteins through the highly conserved HLH domain may represent a previously unrecognized phenomenon.
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Affiliation(s)
- T R Golub
- Division of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
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18
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Affiliation(s)
- J C Wrestler
- Department of Pharmacology, University of North Carolina, Chapel Hill 27599, USA
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19
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Heller C, Pakleza C, Viovy JL. DNA separation with field inversion capillary electrophoresis. Electrophoresis 1995; 16:1423-8. [PMID: 8529608 DOI: 10.1002/elps.11501601235] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have built an automated pulsed field capillary electrophoresis system on the basis of a commercially available device. Using entangled polymer solutions as separating matrix, we demonstrate a considerable improvement of separation of double-stranded DNA in the range of 1-50 kbp under pulsed field conditions. The influence of the main parameters, i.e. pulse frequency and electric field, is studied and the results are compared to existing electrophoresis theories.
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Affiliation(s)
- C Heller
- Laboratoire de Physique des Surfaces et Interfaces (URA CNRS 1379), Institut Curie, Paris, France
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20
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Golub TR, Barker GF, Bohlander SK, Hiebert SW, Ward DC, Bray-Ward P, Morgan E, Raimondi SC, Rowley JD, Gilliland DG. Fusion of the TEL gene on 12p13 to the AML1 gene on 21q22 in acute lymphoblastic leukemia. Proc Natl Acad Sci U S A 1995; 92:4917-21. [PMID: 7761424 PMCID: PMC41818 DOI: 10.1073/pnas.92.11.4917] [Citation(s) in RCA: 543] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Chromosomal rearrangements involving band 12p13 are found in a wide variety of human leukemias but are particularly common in childhood acute lymphoblastic leukemia. The genes involved in these rearrangements, however, have not been identified. We now report the cloning of a t(12;21) translocation breakpoint involving 12p13 and 21q22 in two cases of childhood pre-B acute lymphoblastic leukemia, in which t(12;21) rearrangements were not initially apparent. The consequence of the translocation is fusion of the helix-loop-helix domain of TEL, an ETS-like putative transcription factor, to the DNA-binding and transactivation domains of the transcription factor AML1. These data show that TEL, previously shown to be fused to the platelet-derived growth factor receptor beta in chronic myelomonocytic leukemia, can be implicated in the pathogenesis of leukemia through its fusion to either a receptor tyrosine kinase or a transcription factor. The TEL-AML1 fusion also indicates that translocations affecting the AML1 gene can be associated with lymphoid, as well as myeloid, malignancy.
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Affiliation(s)
- T R Golub
- Division of Hematology/Oncology, Brigham and Women's Hospital, Boston, MA, USA
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21
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Heller C. Capillary electrophoresis of proteins and nucleic acids in gels and entangled polymer solutions. J Chromatogr A 1995. [DOI: 10.1016/0021-9673(94)01169-f] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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22
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Wagner L, Lai E. Separation of large DNA molecules with high voltage pulsed field gel electrophoresis. Electrophoresis 1994; 15:1078-83. [PMID: 7859711 DOI: 10.1002/elps.11501501161] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have developed two high voltage (3 kV and 10 kV) high speed pulsed field gel electrophoresis systems for the separation of DNA as large as 460 kbp. These systems enable us to combine the rapid speed of high voltages and the separation power of pulsed field electrophoresis to achieve high resolution and short run durations. We found that large DNA fragments can be separated at voltage gradients much higher than commonly used. Yeast chromosomes as large as 460 kbp can be separated in 4 h at 20 V/cm and 1-50 kbp DNA can be rapidly separated in 30 min at 55 V/cm. This is 25 times faster in mobility for the separation of relatively small DNA fragments (< 50 kbp). We have also found an inverse relationship between the voltage applied and the size separation limit at that particular voltage gradient (55 V/cm limits the separation to 50 kbp while 20 V/cm can separate up to 460 kbp). Depending on the size range, DNA can be separated 8- to 25-fold faster and with better resolution than existing electrophoretic systems.
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MESH Headings
- Adenoviruses, Human
- Base Composition
- Chromosomes, Fungal
- DNA/chemistry
- DNA/isolation & purification
- DNA, Fungal/isolation & purification
- DNA, Viral/isolation & purification
- Electrophoresis, Agar Gel/instrumentation
- Electrophoresis, Agar Gel/methods
- Electrophoresis, Gel, Pulsed-Field/instrumentation
- Electrophoresis, Gel, Pulsed-Field/methods
- Molecular Weight
- Saccharomyces cerevisiae
- Sepharose
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Affiliation(s)
- L Wagner
- Department of Pharmacology, University of North Carolina at Chapel Hill 27599-7365
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23
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Mouradian S, Brumley RL, Smith LM. Separating field strength, temperature, and pulsing effects in pulsed field electrophoresis. Electrophoresis 1994; 15:1084-90. [PMID: 7859712 DOI: 10.1002/elps.11501501162] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The utility of pulsed field electrophoresis for DNA sequencing is investigated. Previous studies have indicated a beneficial retardation of sequencing fragments when pulsed fields are employed. The interpretation of these results is complicated, however, by concomitant variations in electric field strength and/or temperature. Methods are presented here permitting discrimination of such mobility effects due to pulsing, field strength, and temperature. It is demonstrated that under the conditions employed here, observed mobility effects are due to electric field variations rather than pulsing. These conditions thus correspond to the low frequency/small molecule limit. The effect of temperature is estimated from the steady state solution to the heat conduction equation under appropriate boundary conditions. No temperature effect upon mobility is operative in the thin gel system employed, due to the high efficiency of heat transfer. However, it is shown that in conventional gel systems large temperature-related mobility effects can occur. These methods for dissecting and understanding mobility effects in pulsed field electrophoresis are expected to be of general utility.
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Affiliation(s)
- S Mouradian
- Department of Chemistry, University of Wisconsin, Madison 53703
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24
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25
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Golub TR, Barker GF, Lovett M, Gilliland DG. Fusion of PDGF receptor beta to a novel ets-like gene, tel, in chronic myelomonocytic leukemia with t(5;12) chromosomal translocation. Cell 1994; 77:307-16. [PMID: 8168137 DOI: 10.1016/0092-8674(94)90322-0] [Citation(s) in RCA: 843] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome characterized by abnormal clonal myeloid proliferation and by progression to acute myelogenous leukemia (AML). CMML thus offers an opportunity to study early genetic events in the transition to AML. A recently recognized subgroup of CMML has a t(5;12)(q33;p13) balanced translocation. We report that the consequence of the t(5;12) translocation is expression of a fusion transcript in which the tyrosine kinase domain of the platelet-derived growth factor receptor beta (PDGFR beta) on chromosome 5 is coupled to a novel ets-like gene, tel, on chromosome 12. The tel-PDGFR beta fusion demonstrates the oncogenic potential of PDGFR beta and may provide a paradigm for early events in the pathogenesis of AML.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Cell Transformation, Neoplastic
- Chromosome Mapping
- Chromosomes, Human, Pair 12
- Chromosomes, Human, Pair 5
- DNA-Binding Proteins/chemistry
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Humans
- Karyotyping
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myelomonocytic, Chronic/genetics
- Molecular Sequence Data
- Polymerase Chain Reaction
- Proto-Oncogene Proteins c-ets
- RNA, Messenger/analysis
- Receptors, Platelet-Derived Growth Factor/genetics
- Receptors, Platelet-Derived Growth Factor/physiology
- Repressor Proteins
- Sequence Analysis, DNA
- Transcription Factors/chemistry
- Transcription Factors/genetics
- Transcription Factors/physiology
- Transcription, Genetic
- Translocation, Genetic/genetics
- ETS Translocation Variant 6 Protein
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Affiliation(s)
- T R Golub
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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26
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Kelly WJ, Huang CM, Asmundson RV. Comparison of
Leuconostoc oenos
Strains by Pulsed-Field Gel Electrophoresis. Appl Environ Microbiol 1993; 59:3969-72. [PMID: 16349099 PMCID: PMC182561 DOI: 10.1128/aem.59.11.3969-3972.1993] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pulsed-field gel electrophoresis of chromosomal DNA digested with
Not
I or
Sfi
I was used to differentiate individual strains of
Leuconostoc oenos. L. oenos
isolates with 13 different restriction digest patterns were detected in New Zealand wines undergoing malolactic fermentation. The average genome size was estimated to be 1,800 kb.
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Affiliation(s)
- W J Kelly
- Horticulture and Food Research Institute, Batchelar Research Centre, Private Bag 11030, Palmerston North, New Zealand
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27
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Belleville S, Beauchemin M, Tremblay M, Noiseux N, Savard P. Homeobox-containing genes in the newt are organized in clusters similar to other vertebrates. Gene 1992; 114:179-86. [PMID: 1351019 DOI: 10.1016/0378-1119(92)90572-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In vertebrates, the majority of homeobox (HBox) genes are found in four clusters and this structural organization is believed to be of functional importance. Many HBox genes sustain their expression in the appendages of the adult newt. To further understand their regulation, the genomic loci of four newt HBox genes (two from the human HBox (HOX)-2 complex and two from the HOX-3 complex) were analysed and compared with homologous loci in other vertebrates. Notophthalmus viridescens HBox (NvHBox) genes were selected from a lambda EMBL3 library and analysed by restriction mapping and nucleotide (nt) sequencing. The nt sequences of the NvHBox genes have a very high degree of homology (more than 90%) with the human and mouse HBox genes, HOX-3.3, HOX-3.4, HOX-2.7 and HOX-2.8. The sequences flanking the HBox are also very homologous to their human and mouse counterparts. Moreover, the size of the DNA spacer separating NvHBox-3.3 from NvHBox-3.4, and NvHBox-2.7 from NvHBox-2.8 in the newt is similar in the homologous regions of the mouse and human, despite there being a C value ten times greater in the newt genome. Finally, three of these NvHBox genes are expressed in the limbs of the adult newt.
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Affiliation(s)
- S Belleville
- Unité d'Ontogénèse et de Génétique Moléculaire, Université Laval, Québec, Canada
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28
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Heller C, Beck S. Field inversion gel electrophoresis in denaturing polyacrylamide gels. Nucleic Acids Res 1992; 20:2447-52. [PMID: 1598202 PMCID: PMC312377 DOI: 10.1093/nar/20.10.2447] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The velocities of single stranded DNA molecules in denaturing polyacrylamide gels during symmetric and asymmetric field inversion were measured at different pulse times and gel concentrations. Under the conditions chosen in our study, pulse times as short as a few milliseconds lead to a retardation of DNA molecules larger than 400 bases. We found that a field inversion with an electric field in the forward direction of about double the strength of that applied in the backward direction is a good compromise between the degree of retardation, the temperature control requirements and the run time of the gel.
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Affiliation(s)
- C Heller
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK
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29
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Potvin F, Thibodeau J, Kirkland JB, Dandenault B, Duchaine C, Poirier GG. Structural analysis of the putative regulatory region of the rat gene encoding poly(ADP-ribose) polymerase. FEBS Lett 1992; 302:269-73. [PMID: 1601134 DOI: 10.1016/0014-5793(92)80457-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A lambda EMBL3 clone containing the first three exons along with part of the 4th exon of the rat poly(ADP-ribose) polymerase gene was isolated from a genomic DNA library. This clone also contains 6.6 kbp of upstream sequences. Nucleotide sequence analysis of the proximal 5' 670 nucleotides flanking the major RNA start site of the rat gene does not reveal significant global homology with the same region of the human gene, but a series of short sequences are identical. Among these sequences are found two putative Sp1 binding sites along with a decanucleotide sequence responsible for the attachment of the transcription factor AP-2.
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Affiliation(s)
- F Potvin
- Laboratoire du métabolisme du poly(ADP-ribose), Endocrinologie moléculaire, Centre Hospitalier de l'Université Laval, Ste-Foy, Québec, Canada
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30
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Rampino NJ, Chrambach A. Conformational correlatives of DNA band compression and bidirectional migration during field inversion gel electrophoresis, detected by quantitative video epifluorescence microscopy. Biopolymers 1991; 31:1297-307. [PMID: 1777581 DOI: 10.1002/bip.360311108] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Individual DNA molecules in the Mb size range were monitored by epifluorescence video microscopy during field inversion gel electrophoresis (FIGE). DNA migrating in an agarose gel gives rise to characteristic V-conformational elements and when doing so exhibits a reduced mobility. When the V-conformational elements per DNA molecule are few, the degree of retardation appears proportional to the number of V's, and since larger DNA species exhibit more V's, to DNA size. For a particular pulse frequency, the proportionality breaks down progressively as the number of V-conformational elements per DNA molecule increases. The loss of proportionality between DNA length and migration rate is being correlated with the macroscopically observed loss of electrophoretic size discrimination known as band compression. For a particular pulsing frequency and size class of DNA, the loss of size discrimination is thought to be due to the different orientations of migration, caused by the asymmetric distribution of V-conformational elements when the number of these elements is moderate. Small and very large DNA by contrast migrate with the direction of the biased field. These events, analyzed by microscopic measurement, are consistent with the known macroscopically observed double-valued mobilities in FIGE.
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Affiliation(s)
- N J Rampino
- Section on Macromolecular Analysis, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
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31
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Heller C, Pohl FM. Field inversion gel electrophoresis with different pulse time ramps. Nucleic Acids Res 1990; 18:6299-304. [PMID: 2243776 PMCID: PMC332495 DOI: 10.1093/nar/18.21.6299] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The influence of different pulse time ramps on the separation of yeast chromosomes with field inversion gel electrophoresis (FIGE) was investigated by the means of two dimensional gel electrophoresis. The problem of band inversion, which makes it difficult to distinguish DNA molecules of different size, has been solved by using double randomized pulse times. A major disadvantage of the field inversion technique is thereby overcome, making this system comparable to other pulsed field techniques.
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Affiliation(s)
- C Heller
- Fakultät für Biologie, Universität Konstanz, FRG
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32
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Oerter KE, Munson PJ, McBride WO, Rodbard D. Computerized estimation of size of nucleic acid fragments using the four-parameter logistic model. Anal Biochem 1990; 189:235-43. [PMID: 2281868 DOI: 10.1016/0003-2697(90)90114-o] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have developed improved methods for statistical estimation of the size of linear duplex DNA after continuous- or pulsed-field electrophoresis in agarose and polyacrylamide gels. We employ the four-parameter logistic model to describe the smooth, symmetrical, sigmoidal relationship between electrophoretic mobility (distance migrated) and log of molecular size (kb): distance = a - d/1 + (size/c)b + d. The four parameters (a,b,c,d) are estimated by nonlinear least-squares curve fitting using the Marquardt-Levenberg algorithm, where a represents an upper plateau, b a slope factor, c the midpoint, and d the lower plateau. Estimates of size for unknown species are accompanied by estimates of the standard error (SE) or coefficient of variation (%CV). A plot of SE and %CV versus size results in a "precision profile" which objectively defines the useful range of the calibration curve. This logistic relationship is more general than the rectangular hyperbola or linear methods, provides excellent goodness of fit, and can be used as a "global" method for the entire calibration curve, rather than as a "local" method for small segments of the curve.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K E Oerter
- Laboratory of Theoretical and Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
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33
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Birren BW, Simon MI, Lai E. The basis of high resolution separation of small DNAs by asymmetric-voltage field inversion electrophoresis and its application to DNA sequencing gels. Nucleic Acids Res 1990; 18:1481-7. [PMID: 2326189 PMCID: PMC330515 DOI: 10.1093/nar/18.6.1481] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We have previously shown that asymmetric-voltage field inversion electrophoresis produces more uniform separation for fragments between 1 and 50 kilobases (kb) than other modes of pulsed field gel electrophoresis. We now report on the basis of this phenomenon. As in conventional electrophoresis, the pulsed field mobility of DNAs between 1 and 50 kb varies with voltage in a size dependent manner. The complex migration pattern obtained with asymmetric-voltage field inversion electrophoresis reflects the difference between the mobilities of each sized fragment under the conditions used for the forward and reverse fields. We have applied this technique to DNA sequencing gels and find improvement in resolution for single-stranded fragments in polyacrylamide gels.
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Affiliation(s)
- B W Birren
- Division of Biology, California Institute of Technology, Pasadena 91125
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34
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Abstract
The mobilities of oligomers of phage lambda DNA and of yeast chromosomes in agarose gels during field inversion gel electrophoresis (FIGE) were measured at different pulse times and electric fields. Also the ratios between forward and backward pulse times and/or field gradients were varied. The problem of 'band inversion' during FIGE, leading to an ambiguity in the mobility of large DNA fragments, was solved by using two dimensional gel electrophoresis with different parameters in the first and second dimension. The results are compared with those obtained with other pulsed electrophoresis systems and with a theoretical model.
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Affiliation(s)
- C Heller
- Fakultät für Biologie, Universität Konstanz, FRG
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35
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Birren BW, Hood L, Lai E. Pulsed field gel electrophoresis: studies of DNA migration made with the programmable, autonomously-controlled electrode electrophoresis system. Electrophoresis 1989; 10:302-9. [PMID: 2527739 DOI: 10.1002/elps.1150100506] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have studied the migration of DNA in pulsed field agarose gels under a variety of electrophoresis conditions. We have made use of an instrument which can generate electric fields of any orientation, magnitude, or duration to compare different separation techniques for DNA molecules of from 1 to several thousand kilobase pairs. We discuss the capabilities of the system and present results of gel runs in which electrophoresis conditions were changed individually or in combination. The mobility of DNA in pulsed field gels is shown to reflect a number of interdependent physical parameters.
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Affiliation(s)
- B W Birren
- Division of Biology, California Institute of Technology, Pasadena 91125
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