Tn502 and Tn512 Are res Site Hunters That Provide Evidence of Resolvase-Independent Transposition to Random Sites

ABSTRACT In this study, we report on the transposition behavior of the mercury(II) resistance transposons Tn502 and Tn512, which are members of the Tn5053 family. These transposons exhibit targeted and oriented insertion in the par region of plasmid RP1, since par-encoded components, namely, the ParA resolvase and its cognate res region, are essential for such transposition. Tn502 and, under some circumstances, Tn512 can transpose when par is absent, providing evidence for an alternative, par-independent pathway of transposition. We show that the alternative pathway proceeds by a two-step replicative process involving random target selection and orientation of insertion, leading to the formation of cointegrates as the predominant product of the first stage of transposition. Cointegrates remain unresolved because the transposon-encoded (TniR) recombination system is relatively inefficient, as is the host-encoded (RecA) system. In the presence of the res-ParA recombination system, TniR-mediated (and RecA-mediated) cointegrate resolution is highly efficient, enabling resolution both of cointegrates involving functional transposons (Tn502 and Tn512) and of defective elements (In0 and In2). These findings implicate the target-encoded accessory functions in the second stage of transposition as well as in the first. We also show that the par-independent pathway enables the formation of deletions in the target molecule.

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The Two-Stage Recognition Method Based on Texture Signals of the Heterogeneous Unsteady Iris

International Journal of Pattern Recognition and Artificial Intelligence ◽

10.1142/s0218001422500094 ◽

2021 ◽

Author(s):

Shuai Liu ◽

Yuanning Liu ◽

Xiaodong Zhu ◽

Jing Liu ◽

Guang Huo ◽

...

Keyword(s):

Iris Recognition ◽

Recognition Accuracy ◽

Texture Features ◽

Unsteady State ◽

Recognition Method ◽

Two Stage ◽

Second Stage ◽

Highly Efficient ◽

Training Samples ◽

Gray Values

In this paper, a two-stage multi-category recognition structure based on texture features is proposed. This method can solve the problem of the decline in recognition accuracy in the scene of lightweight training samples. Besides, the problem of recognition effect different in the same recognition structure caused by the unsteady iris can also be solved. In this paper’s structure, digitized values of the edge shape in the iris texture of the image are set as the texture trend feature, while the differences between the gray values of the image obtained by convolution are set as the grayscale difference feature. Furthermore, the texture trend feature is used in the first-stage recognition. The template category that does not match the tested iris is the elimination category, and the remaining categories are uncertain categories. Whereas, in the second-stage recognition, uncertain categories are adopted to determine the iris recognition conclusion through the grayscale difference feature. Then, the experiment results using the JLU iris library show that the method in this paper can be highly efficient in multi-category heterogeneous iris recognition under lightweight training samples and unsteady state.

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GO, SiO2, and SnO2 nanomaterials as highly efficient adsorbents for Zn2+ from industrial wastewater—A second stage treatment to electrically enhanced membrane bioreactor

Journal of Water Process Engineering ◽

10.1016/j.jwpe.2019.100815 ◽

2019 ◽

Vol 31 ◽

pp. 100815 ◽

Cited By ~ 8

Author(s):

Menatalla Ahmed ◽

Maria Elektorowicz ◽

Shadi W. Hasan

Keyword(s):

Industrial Wastewater ◽

Membrane Bioreactor ◽

Second Stage ◽

Highly Efficient ◽

Electrically Enhanced

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Engineering lacZ Reporter Gene into an ephA8 Bacterial Artificial Chromosome Using a Highly Efficient Bacterial Recombination System

BMB Reports ◽

10.5483/bmbrep.2007.40.5.656 ◽

2007 ◽

Vol 40 (5) ◽

pp. 656-661 ◽

Cited By ~ 7

Author(s):

Yu-Jin Kim ◽

Eun-Sook Song ◽

Soon-Young Choi ◽

Soo-Chul Park

Keyword(s):

Bacterial Artificial Chromosome ◽

Reporter Gene ◽

Artificial Chromosome ◽

Lacz Reporter ◽

Lacz Reporter Gene ◽

Highly Efficient ◽

Recombination System

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Highly efficient and inducible DNA excision in transgenic silkworms using the FLP/FRT site-specific recombination system

Transgenic Research ◽

10.1007/s11248-016-9970-4 ◽

2016 ◽

Vol 25 (6) ◽

pp. 795-811 ◽

Cited By ~ 2

Author(s):

Dingpei Long ◽

Weijian Lu ◽

Zhanzhang Hao ◽

Zhonghuai Xiang ◽

Aichun Zhao

Keyword(s):

Site Specific ◽

Site Specific Recombination ◽

Highly Efficient ◽

Recombination System ◽

Transgenic Silkworms ◽

Site Specific Recombination System

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New methods for tightly regulated gene expression and highly efficient chromosomal integration of cloned genes forMethanosarcinaspecies

Archaea ◽

10.1155/2008/534081 ◽

2008 ◽

Vol 2 (3) ◽

pp. 193-203 ◽

Cited By ~ 60

Author(s):

Adam M. Guss ◽

Michael Rother ◽

Jun Kai Zhang ◽

Gargi Kulkkarni ◽

William W. Metcalf

Keyword(s):

Chromosomal Integration ◽

Recombination Site ◽

Integrase Gene ◽

Site Specific ◽

Site Specific Recombination ◽

Highly Efficient ◽

Recombination System ◽

Regulated Gene Expression ◽

Hybrid Promoters ◽

Site Specific Recombination System

A highly efficient method for chromosomal integration of cloned DNA intoMethanosarcina spp.was developed utilizing the site-specific recombination system from theStreptomycesphage φC31. Host strains expressing the φC31 integrase gene and carrying an appropriate recombination site can be transformed with non-replicating plasmids carrying the complementary recombination site at efficiencies similar to those obtained with self-replicating vectors. We have also constructed a series of hybrid promoters that combine the highly expressedM. barkeriPmcrBpromoter with binding sites for the tetracycline-responsive, bacterial TetR protein. These promoters are tightly regulated by the presence or absence of tetracycline in strains that express thetetRgene. The hybrid promoters can be used in genetic experiments to test gene essentiality by placing a gene of interest under their control. Thus, growth of strains withtetR-regulated essential genes becomes tetracycline-dependent. A series of plasmid vectors that utilize the site-specific recombination system for construction of reporter gene fusions and for tetracycline regulated expression of cloned genes are reported. These vectors were used to test the efficiency of translation at a variety of start codons. Fusions using an ATG start site were the most active, whereas those using GTG and TTG were approximately one half or one fourth as active, respectively. The CTG fusion was 95% less active than the ATG fusion.

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A highly efficient targeted recombination system for engineering linear chromosomes of industrial bacteria Streptomyces

The Journal of General and Applied Microbiology ◽

10.2323/jgam.2017.11.004 ◽

2018 ◽

Vol 64 (4) ◽

pp. 167-173 ◽

Cited By ~ 1

Author(s):

Hung-Yin Pan ◽

Carton W. Chen ◽

Chih-Hung Huang

Keyword(s):

Highly Efficient ◽

Recombination System ◽

Linear Chromosomes ◽

Targeted Recombination

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Altered Fine Structure of B Lymphocytes Correlated with Defective Terminal Differentiation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007237x ◽

1973 ◽

Vol 31 ◽

pp. 386-387

Author(s):

Dale E. Bockman ◽

L. Y. Frank Wu ◽

Alexander R. Lawton ◽

Max D. Cooper

Keyword(s):

Immune Deficiency ◽

B Lymphocytes ◽

Plasma Cells ◽

Present Report ◽

Specific Antigen ◽

Terminal Differentiation ◽

Second Stage ◽

Two Stages ◽

Deficiency Diseases ◽

Cell Line Generation

B-lymphocytes normally synthesize small amounts of immunoglobulin, some of which is incorporated into the cell membrane where it serves as receptor of antigen. These cells, on contact with specific antigen, proliferate and differentiate to plasma cells which synthesize and secrete large quantities of immunoglobulin. The two stages of differentiation of this cell line (generation of B-lymphocytes and antigen-driven maturation to plasma cells) are clearly separable during ontogeny and in some immune deficiency diseases. The present report describes morphologic aberrations of B-lymphocytes in two diseases in which second stage differentiation is defective.

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Cryomicroscopy of multiphase latices

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089615 ◽

1991 ◽

Vol 49 ◽

pp. 1060-1061

Author(s):

O. L. Shaffer ◽

M.S. El-Aasser ◽

C. L. Zhao ◽

M. A. Winnik ◽

R. R. Shivers

Keyword(s):

Electron Microscopy ◽

Radiation Damage ◽

Freeze Fracture ◽

Particle Morphology ◽

Second Stage ◽

Transmission Electron ◽

Important Approach ◽

Carbon Coated ◽

Preparation Techniques

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.

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Observations on the growth of barium bismuth oxide thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100120783 ◽

1992 ◽

Vol 50 (1) ◽

pp. 76-77

Author(s):

M G. Norton ◽

E.S. Hellman ◽

E.H. Hartford ◽

C.B. Carter

Keyword(s):

Substrate Temperature ◽

Deposition Process ◽

Nucleation Layer ◽

Second Stage ◽

Device Applications ◽

High Transition ◽

Substrate Temperatures ◽

Oriented Material ◽

Barium Bismuth ◽

Superconductor Device

The bismuthates (for example, Ba1-xKxBiO3) represent a class of high transition temperature superconductors. The lack of anisotropy and the long coherence length of the bismuthates makes them technologically interesting for superconductor device applications. To obtain (100) oriented Ba1-xKxBiO3 films on (100) oriented MgO, a two-stage deposition process is utilized. In the first stage the films are nucleated at higher substrate temperatures, without the potassium. This process appears to facilitate the formation of the perovskite (100) orientation on (100) MgO. This nucleation layer is typically between 10 and 50 nm thick. In the second stage, the substrate temperature is reduced and the Ba1-xKxBiO3 is grown. Continued growth of (100) oriented material is possible at the lower substrate temperature.

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