Analysis of in vivo DNA repair rates of alkylpurines in defined segments of human DNA

Conference · Mon Mar 11 04:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5370606

Wright, P W; Weiss, R B; Gallagher, P E ^[1]

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1. West Virginia Univ., Morgantown (United States)

Simple alkylating agents, such as methyl methanesulfonate or dimethyl sulfate, react with DNA bases to yield 7-methylguanine as the major product, with 3-methyladenine and O{sup 6}-methylguanine in lesser amounts. It has been shown that these alkylated bases are actively repaired in vivo in both bacteria and mammalian cells. The authors have employed a polymerase chain reaction assay to examine the in vivo formation and repair rates of alkylpurines in a defined segment of the human dihydrofolate reductase gene. Human lymphoblasts were treated with varying doses of dimethyl sulfate and a limiting concentration of the isolated DNA was used in the amplification reactions. Alkylation resulted in a dose-dependent loss of primer extension, presumably due to 3-methyladenine blockage of the Taq polymerase. Analysis of the amplified reaction products by radioautography following polyacrylamide gel electrophoresis showed that the prematurely truncated amplified products terminated at adenines as compared to DNA sequencing fragments. Heat treatment of the amplified DNAs prior to gel analysis resulted in fragments that terminated at adenines and guanines. The lymphoblast DNA was isolated at various times after alkylation and the repair rate of alkyladenine in the DHFR fragment was found to be more efficient than that of the overall genome.

• OSTI ID: 5370606
• Report Number(s): CONF-9104107--
• Conference Information: Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Journal Volume: 5:4
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKYLATING AGENTS
ALKYLATION
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BLOOD
BLOOD CELLS
BODY FLUIDS
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
DNA REPAIR
DNA SEQUENCING
DOSE-RESPONSE RELATIONSHIPS
ELECTROPHORESIS
ENZYMES
ESTERS
GENES
GENETIC EFFECTS
IN VIVO
LEUKOCYTES
LYMPHOCYTES
MAMMALS
MAN
MATERIALS
METHYL METHANESULFONATE
MUTAGENS
NUCLEOTIDYLTRANSFERASES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDOREDUCTASES
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
PRIMATES
PROTEINS
REPAIR
SOMATIC CELLS
STRUCTURAL CHEMICAL ANALYSIS
SULFONIC ACID ESTERS
TRANSFERASES
VERTEBRATES