Cell Division Processes
Mostrando 25-36 de 208 artigos, teses e dissertações.
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25. A small, physiological electric field orients cell division
We report on an observation that the orientation of cell division is directed by small, applied electric fields (EFs). Cultured human corneal epithelial cells were exposed to a direct-current EF of physiological magnitude. Cells divided while attached to the culture dish, and most did so with a cleavage plane perpendicular to the EF vector. There are many in
The National Academy of Sciences.
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26. Coordination between chromosome replication and cell division in Escherichia coli.
Cell division properties of Escherichia coli B/r containing either a dnaC or a dnaI mutation were examined. Incubation at nonpermissive temperature resulted in the eventual production of cells of approximately normal size, or slightly smaller, which lacked chromosomal DNA. The cell division patterns in cultures which were grown at permissive temperature and
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27. The β-Subunit of the Arabidopsis G Protein Negatively Regulates Auxin-Induced Cell Division and Affects Multiple Developmental ProcessesW⃞
Plant cells respond to low concentrations of auxin by cell expansion, and at a slightly higher concentration, these cells divide. Previous work revealed that null mutants of the α-subunit of a putative heterotrimeric G protein (GPA1) have reduced cell division. Here, we show that this prototypical G protein complex acts mechanistically by controlling auxin
American Society of Plant Biologists.
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28. Transcriptome analysis during cell division in plants
Using synchronized tobacco Bright Yellow-2 cells and cDNA-amplified fragment length polymorphism-based genomewide expression analysis, we built a comprehensive collection of plant cell cycle-modulated genes. Approximately 1,340 periodically expressed genes were identified, including known cell cycle control genes as well as numerous unique candidate regulato
National Academy of Sciences.
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29. Inhibition and restart of initiation of chromosome replication: effects on exponentially growing Escherichia coli cells.
Escherichia coli strains in which initiation of chromosome replication could be specifically blocked while other cellular processes continued uninhibited were constructed. Inhibition of replication resulted in a reduced growth rate and in inhibition of cell division after a time period roughly corresponding to the sum of the lengths of the C and D periods. T
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30. The Tangled1 gene is required for spatial control of cytoskeletal arrays associated with cell division during maize leaf development.
The cytoskeleton plays a major role in the spatial regulation of plant cell division and morphogenesis. Arrays of microtubules and actin filaments present in the cell cortex during prophase mark sites to which phragmoplasts and associated cell plates are guided during cytokinesis. During interphase, cortical microtubules are believed to influence the orienta
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31. Reactive oxygen species and ethylene play a positive role in lateral root base nodulation of a semiaquatic legume
Lateral root base nodulation on the tropical, semiaquatic legume Sesbania rostrata results from two coordinated, Nod factor-dependent processes: formation of intercellular infection pockets and induction of cell division. Infection pocket formation is associated with cell death and production of hydrogen peroxide. Pharmacological experiments showed that ethy
National Academy of Sciences.
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32. Transposon Insertions in the Flavobacterium johnsoniae ftsX Gene Disrupt Gliding Motility and Cell Division
Flavobacterium johnsoniae is a gram-negative bacterium that exhibits gliding motility. To determine the mechanism of flavobacterial gliding motility, we isolated 33 nongliding mutants by Tn4351 mutagenesis. Seventeen of these mutants exhibited filamentous cell morphology. The region of DNA surrounding the transposon insertion in the filamentous mutant CJ101-
American Society for Microbiology.
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33. A Radial Concentration Gradient of Indole-3-Acetic Acid Is Related to Secondary Xylem Development in Hybrid Aspen.
The radial distribution pattern of indole-3-acetic acid (IAA) was determined across the developing tissues of the cambial region in the stem of hybrid aspen (Populus tremula L. x Populus tremuloides Michx). IAA content was measured in consecutive tangential cryo-sections using a microscale mass spectrometry technique. Analysis was performed with wild-type an
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34. An essential single domain response regulator required for normal cell division and differentiation in Caulobacter crescentus.
Signal transduction pathways mediated by sensor histidine kinases and cognate response regulators control a variety of physiological processes in response to environmental conditions. Here we show that in Caulobacter crescentus these systems also play essential roles in the regulation of polar morphogenesis and cell division. Previous studies have implicated
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35. Effects of Nitrogen on Mesophyll Cell Division and Epidermal Cell Elongation in Tall Fescue Leaf Blades 1
Leaf elongation rate (LER) in grasses is dependent on epidermal cell supply (number) and on rate and duration of epidermal cell elongation. Nitrogen (N) fertilization increases LER. Longitudinal sections from two genotypes of tall fescue (Festuca arundinacea Schreb.), which differ by 50% in LER, were used to quantify the effects of N on the components of epi
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36. RML1 and RML2, Arabidopsis genes required for cell proliferation at the root tip.
New cells are produced from the meristematic tissues located at the shoot and root tip throughout the life of higher plants. To investigate the genetic mechanism regulating meristematic activity, we isolated and characterized four single-gene, recessive mutants in Arabidopsis thaliana called root meristemless (rml). Complementation tests identified two RML l