Introduction of exogenous DNA into Chlamydomonas reinhardtii by electroporation.

The fate of exogenous DNA introduced into Chlamydomonas reinhardtii by electroporation was analyzed. With single and double electrical pulses, plasmids as large as 14 kb were introduced into cells with and without intact cell walls. Within hours after introduction, exogenous plasmid DNA was associated with nuclei isolated from cells; several weeks after introduction, exogenous DNA was stably integrated into the Chlamydomonas genome. These studies establish electroporation as a method for introducing DNA, and potentially other molecules, into C. reinhardtii.

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DNA repair and the evolution of transformation in Bacillus subtilis. II. Role of inducible repair.

Genetics ◽

10.1093/genetics/121.3.411 ◽

1989 ◽

Vol 121 (3) ◽

pp. 411-422

Author(s):

M F Wojciechowski ◽

M A Hoelzer ◽

R E Michod

Keyword(s):

Dna Repair ◽

Bacillus Subtilis ◽

Plasmid Dna ◽

Excision Repair ◽

Physiological State ◽

Transformation Rate ◽

Exogenous Dna ◽

Expression Of Genes ◽

Cell Subpopulations ◽

Experimental Treatments

Abstract In Bacillus subtilis, DNA repair and recombination are intimately associated with competence, the physiological state in which the bacterium can bind, take up and recombine exogenous DNA. Previously, we have shown that the homologous DNA transformation rate (ratio of transformants to total cells) increases with increasing UV dosage if cells are transformed after exposure to UV radiation (UV-DNA), whereas the transformation rate decreases if cells are transformed before exposure to UV (DNA-UV). In this report, by using different DNA repair-deficient mutants, we show that the greater increase in transformation rate in UV-DNA experiments than in DNA-UV experiments does not depend upon excision repair or inducible SOS-like repair, although certain quantitative aspects of the response do depend upon these repair systems. We also show that there is no increase in the transformation rate in a UV-DNA experiment when repair and recombination proficient cells are transformed with nonhomologous plasmid DNA, although the results in a DNA-UV experiment are essentially unchanged by using plasmid DNA. We have used din operon fusions as a sensitive means of assaying for the expression of genes under the control of the SOS-like regulon in both competent and noncompetent cell subpopulations as a consequence of competence development and our subsequent experimental treatments. Results indicate that the SOS-like system is induced in both competent and noncompetent subpopulations in our treatments and so should not be a major factor in the differential response in transformation rate observed in UV-DNA and DNA-UV treatments. These results provide further support to the hypothesis that the evolutionary function of competence is to bring DNA into the cell for use as template in the repair of DNA damage.

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Even Visually Intact Cell Walls in Waterlogged Archaeological Wood Are Chemically Deteriorated and Mechanically Fragile: A Case of a 170 Year-Old Shipwreck

Molecules ◽

10.3390/molecules25051113 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1113 ◽

Cited By ~ 1

Author(s):

Liuyang Han ◽

Xingling Tian ◽

Tobias Keplinger ◽

Haibin Zhou ◽

Ren Li ◽

...

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Intact Cell ◽

Nitrogen Adsorption ◽

Wet Chemistry ◽

Archaeological Wood ◽

Waterlogged Archaeological Wood ◽

X Ray Scattering ◽

Crystallite Structure ◽

Cell Wall Mechanics

Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, 13C-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N2 nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of β-O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks.

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Biochemical contributions to the taxonomic status of the Endogonaceae

Canadian Journal of Botany ◽

10.1139/b79-038 ◽

1979 ◽

Vol 57 (3) ◽

pp. 284-291 ◽

Cited By ~ 34

Author(s):

A. C. M. Weijman ◽

H. L. C. Meuzelaar

Keyword(s):

Cell Walls ◽

Intact Cell ◽

Taxonomic Status ◽

Fungal Cell ◽

Saprolegnia Ferax ◽

Mucor Mucedo ◽

Allomyces Arbuscula ◽

Liquid Chromatographic Analysis ◽

Liquid Chromatographic ◽

Curie Point Pyrolysis

The Endogonaceae are generally considered as zygomycete representatives, although zygospores have only been observed in the type genus Endogone. Consequently, the oomycetous or chytridiomycetous nature of some fungi classified in the Endogonaceae cannot be excluded. The presence or absence of chitin in cell walls can indicate the oomycetous or zygomycetous relationship. The occurrence of glucosamine was investigated by gas–liquid chromatographic analysis of intact cell hydrolyzates, a process requiring small quantities of material. The cells were also characterized by Curie-point pyrolysis mass spectrometry. These two techniques were applied to lyophilized spores or sporocarps of Endogone, Glomus, Glaziella, and Gigaspora. Mucor mucedo, Allomyces arbuscula, Pythium spinosum, and Saprolegnia ferax were included for comparison.In all endogonaceous isolates tested, a strong predominance of chitin was indicated, supporting their classification within the Zygomycetes.The phylogenetic significance of chitin and cellulose distribution in fungal cell walls is discussed.

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Chitin Nanowhiskers Mediate Transformation of Escherichia coli by Exogenous Plasmid DNA

Journal of Biotechnology & Biomaterials ◽

10.4172/2155-952x.1000114 ◽

2011 ◽

Vol 01 (06) ◽

Cited By ~ 5

Author(s):

Alisa Mera ◽

Jun Araki ◽

Takashi Ohtsuki

Keyword(s):

Escherichia Coli ◽

Plasmid Dna ◽

Chitin Nanowhiskers ◽

Exogenous Plasmid

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Asbestos fibers mediate transformation of monkey cells by exogenous plasmid DNA.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.85.20.7670 ◽

1988 ◽

Vol 85 (20) ◽

pp. 7670-7674 ◽

Cited By ~ 49

Author(s):

J. D. Appel ◽

T. M. Fasy ◽

D. S. Kohtz ◽

J. D. Kohtz ◽

E. M. Johnson

Keyword(s):

Plasmid Dna ◽

Asbestos Fibers ◽

Exogenous Plasmid

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Cationic Peptide Mediated Oligonucleotide Delivery to DU145 Prostate Cancer Cells - Cell Surface Binding Detected by High Resolution SEM

Microscopy and Microanalysis ◽

10.1017/s1431927600015282 ◽

1999 ◽

Vol 5 (S2) ◽

pp. 392-393

Author(s):

Joan F. Karr ◽

Robert P. Apkarian ◽

John A. Petros

Keyword(s):

Prostate Cancer ◽

High Resolution ◽

Cancer Cells ◽

Plasmid Dna ◽

Cell Membranes ◽

Cationic Peptides ◽

Cationic Peptide ◽

Prostate Cancer Cells ◽

Surface Binding ◽

Exogenous Dna

Transfection of mammalian cells can be enhanced by forming complexes between exogenous DNA and cationic peptides which facilitate DNA transport through cell membranes. Although complexes of plasmid DNA and cationic peptides have been characterized by microscopy, little is known about the complexes formed between oligonucleotides (ODN) and cationic peptides or how the ultrastructure of these complexes affects the intracellular delivery via the cell membrane. Because ODN have potential as therapeutic reagents in the treatment of many diseases, there is a need to develop improved methods for effective delivery of these molecules. By analyzing molecular interactions between cationic peptides and ODN and their effects on cell membranes, cell viability, and DNA delivery, improved delivery compounds can be designed. In this paper, we compare the interactions of a 28 base ODN with three cationic peptides: a novel compound, MNLEK (H-Met-(Nle-Lys4)7-Nle-NH2), an established transfection reagent, poly(L-lysine) (∼ 54 kDa), and a recently described cationic peptide which delivers both plasmid DNA and antisense ODN to cells, KALA (WEAKLAKALAKALAKHLAKALAKALKACEA).For high resolution scanning electron microscopy (HRSEM), DU145 human prostate cancer cells were grown overnight on poly-(D-lysine) coated, UV irradiated silicon chips.

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341. Exogenous Plasmid DNA Sequences Differentially Affect Episomal Transgene Silencing in Liver and Muscle

Molecular Therapy ◽

10.1016/s1525-0016(16)44547-8 ◽

2007 ◽

Vol 15 ◽

pp. S129

Keyword(s):

Dna Sequences ◽

Plasmid Dna ◽

Transgene Silencing ◽

Exogenous Plasmid

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A SEROLOGICAL STUDY OF CELL WALLS OF CERTAIN LACTIC ACID BACTERIA

Canadian Journal of Microbiology ◽

10.1139/m62-084 ◽

1962 ◽

Vol 8 (5) ◽

pp. 629-637

Author(s):

K. L. Chung ◽

Roma Z. Hawirko

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Intact Cell ◽

Synthetic Medium ◽

Specific Cell ◽

Intact Cells ◽

Common Antigens ◽

Species Specific ◽

Relationship Of ◽

The Relationship

From three species of Lactobacillus and three species of Streptococcus, cultured in a synthetic medium, cell walls were isolated following sonic disintegration and purified by washing. Sera against each species were prepared by injecting three rabbits with cell walls, and three with intact cells. Reciprocal agglutination tests were carried out with unabsorbed and absorbed antisera. More kinds of antibodies were detected with cell-wall antisera than with intact-cell antisera. Many species in the two genera shared common antigens. S. faecalis was the exception. Certain antigens believed to be complex haptens in nature reacted with heterologous antisera. Haemagglutination of tanned erythrocytes sensitized with a particulate cell-wall suspension showed fewer cross reactions than agglutination of intact-cell suspensions.The evidence presented shows the possibility of using antisera against species-specific cell-wall antigens for the identification of these species. The relationship of these species is discussed.

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