Genetic and molecular events in transformation ofHaemophilus influenzae with plasmid RSF 0885 carrying cloned segments of chromosomal DNA

1981 ◽  
Vol 3 (4) ◽  
pp. 431-438 ◽  
Author(s):  
N. K. Notani
Keyword(s):  
Chromosomal Dna ◽  
Molecular Events ◽  
Ofhaemophilus Influenzae

scholarly journals A quantitative model for cyclin-dependent kinase control of the cell cycle: revisited

2011 ◽  
Vol 366 (1584) ◽  
pp. 3572-3583 ◽  
Author(s):  
Frank Uhlmann ◽  
Céline Bouchoux ◽  
Sandra López-Avilés
Keyword(s):  
Cell Cycle ◽  
Eukaryotic Cell ◽  
Quantitative Model ◽  
S Phase ◽  
Cyclin Dependent Kinase ◽  
Genomic Integrity ◽  
Chromosomal Dna ◽  
Substrate Specificities ◽  
Daughter Cells ◽  
Molecular Events

The eukaryotic cell division cycle encompasses an ordered series of events. Chromosomal DNA is replicated during S phase of the cell cycle before being distributed to daughter cells in mitosis. Both S phase and mitosis in turn consist of an intricately ordered sequence of molecular events. How cell cycle ordering is achieved, to promote healthy cell proliferation and avert insults on genomic integrity, has been a theme of Paul Nurse's research. To explain a key aspect of cell cycle ordering, sequential S phase and mitosis, Stern & Nurse proposed ‘A quantitative model for cdc2 control of S phase and mitosis in fission yeast’. In this model, S phase and mitosis are ordered by their dependence on increasing levels of cyclin-dependent kinase (Cdk) activity. Alternative mechanisms for ordering have been proposed that rely on checkpoint controls or on sequential waves of cyclins with distinct substrate specificities. Here, we review these ideas in the light of experimental evidence that has meanwhile accumulated. Quantitative Cdk control emerges as the basis for cell cycle ordering, fine-tuned by cyclin specificity and checkpoints. We propose a molecular explanation for quantitative Cdk control, based on thresholds imposed by Cdk-counteracting phosphatases, and discuss its implications.

scholarly journals Conjugal Transfer of Chromosomal DNA Contributes to Genetic Variation in the Oral Pathogen Porphyromonas gingivalis

2007 ◽  
Vol 189 (17) ◽  
pp. 6382-6388 ◽  
Author(s):  
Gena D. Tribble ◽  
Gwyneth J. Lamont ◽  
Ann Progulske-Fox ◽  
Richard J. Lamont
Keyword(s):  
Genetic Variation ◽  
Porphyromonas Gingivalis ◽  
Significant Degree ◽  
Dna Transfer ◽  
Chromosomal Dna ◽  
Adaptation Mechanism ◽  
Oral Pathogen ◽  
Type Iv ◽  
Molecular Events

ABSTRACT Porphyromonas gingivalis is a major oral pathogen that contributes to the development of periodontal disease. There is a significant degree of genetic variation among strains of P. gingivalis, and the population structure has been predicted to be panmictic, indicating that horizontal DNA transfer and recombination between strains are likely. The molecular events underlying this genetic exchange are not understood, although a putative type IV secretion system is present in the genome sequence of strain W83, implying that DNA conjugation may be responsible for genetic transfer in these bacteria. In this study, we provide in vitro evidence for the horizontal transfer of DNA using plasmid- and chromosome-based assays. In the plasmid assays, Bacteroides-derived shuttle vectors were tested for transfer from P. gingivalis strains into Escherichia coli. Of the eight strains tested, five were able to transfer DNA into E. coli by a mechanism most consistent with conjugation. Additionally, strains W83 and 33277 tested positive for the transfer of chromosomally integrated antibiotic resistance markers. Ten chimeras resulting from the chromosomal transfer assay were further analyzed by Southern hybridization and were shown to have exchanged DNA fragments of between 1.1 and 5.6 kb, but the overall strain identity remained intact. Chimeras showed phenotypic changes in the ability to accrete into biofilms, implying that DNA transfer events are sufficient to generate measurable changes in complex behaviors. This ability to transfer chromosomal DNA between strains may be an adaptation mechanism in the complex environment of the host oral cavity.

Transformation ofHaemophilus influenzae following electroporation with plasmid and chromosomal DNA

1992 ◽  
Vol 24 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Jane K. Setlow ◽  
William L. Albritton
Keyword(s):  
Chromosomal Dna ◽  
Ofhaemophilus Influenzae

Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

1992 ◽  
Vol 50 (1) ◽  
pp. 418-419
Author(s):  
D. L. Taylor
Keyword(s):  
Living Cells ◽  
Cellular Level ◽  
Molecular Techniques ◽  
Cellular Functions ◽  
Macromolecular Assemblies ◽  
Cell Functions ◽  
Molecular Events ◽  
Yield Information ◽  
Full Knowledge ◽  
Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

Molecular events in a large series of advanced stage III-IV adrenocortical cancer: looking for new therapeutic options

2019 ◽  
Author(s):  
Martino Maria Cristina De ◽  
Ludovic Lacroix ◽  
Sebastien Aubert ◽  
Rossella Libe ◽  
Ghuzlan Abir Al ◽  
...  
Keyword(s):  
Large Series ◽  
Therapeutic Options ◽  
Stage Iii ◽  
Advanced Stage ◽  
Adrenocortical Cancer ◽  
Molecular Events
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