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Author Halweg, Christopher ♦ Thompson, William F. ♦ Spiker, Steven
Source World Health Organization (WHO)-Global Index Medicus
Content type Text
Publisher American Society of Plant Biologists
File Format HTM / HTML
Language English
Difficulty Level Medium
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Genetics and evolution ♦ Natural history of organisms ♦ Microorganisms, fungi & algae ♦ Technology ♦ Medicine & health ♦ Human physiology ♦ Pharmacology and therapeutics ♦ Diseases ♦ Manufacture for specific uses ♦ Precision instruments & other devices
Subject Domain (in MeSH) Eukaryota ♦ Bacteria ♦ Organisms ♦ Amino Acids, Peptides, and Proteins ♦ Nucleic Acids, Nucleotides, and Nucleosides ♦ Chemicals and Drugs ♦ Diagnosis ♦ Analytical, Diagnostic and Therapeutic Techniques and Equipment ♦ Chemical Phenomena ♦ Genetic Phenomena ♦ Biological Sciences
Subject Keyword Discipline Botany ♦ Flow Cytometry ♦ Methods ♦ Gene Expression Regulation, Plant ♦ Matrix Attachment Regions ♦ Tobacco ♦ Genetics ♦ Transgenes ♦ Agrobacterium Tumefaciens ♦ Dna, Bacterial ♦ Green Fluorescent Proteins ♦ Metabolism ♦ Plants, Genetically Modified ♦ Promoter Regions, Genetic ♦ Recombinant Fusion Proteins ♦ Cytology ♦ Transformation, Genetic ♦ Journal Article ♦ Research Support, U.s. Gov't, Non-p.h.s.
Abstract Many studies in both plant and animal systems have shown that matrix attachment regions (MARs) can increase expression of transgenes in whole organisms or cells in culture. Because histochemical assays often indicate variegated transgene expression, a question arises: Do MARs increase transgene expression by increasing the percentage of cells expressing the transgene (likelihood), by increasing the level of expression in expressing cells (magnitude), or both? To address this question, we used flow cytometry to measure green fluorescent protein (GFP) expression in individual tobacco (Nicotiana tabacum) cells from lines transformed by Agrobacterium tumefaciens. We conclude that MAR-mediated overall increases in transgene expression involve both likelihood and magnitude. On average, cell lines transformed with the Rb7 MAR-containing vector expressed GFP at levels 2.0- to 3.7-fold higher than controls. MAR lines had fewer nonexpressing cells than control lines (10% versus 45%), and the magnitude of GFP expression in expressing cells was greater in MAR lines by 1.9- to 2.9-fold. We also show that flow cytometry measurements on cells from isogenic lines are consistent with those from populations of independently transformed cell lines. By obviating the need to establish isogenic lines, this use of flow cytometry could greatly simplify the evaluation of MARs or other sequence elements that affect transgene expression.
Description Country affiliation: United States
Author Affiliation: Halweg C ( Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695-7614, USA.)
ISSN 10404651
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Reading ♦ Research ♦ Self Learning
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2005-02-01
Publisher Place United States
e-ISSN 1531298X
Volume Number 17
Issue Number 2

Source: WHO-Global Index Medicus