DNA-mediated transfer of a human DNA repair gene that controls sister chromatid exchange

1985 ◽  
Vol 5 (4) ◽  
pp. 881-884
Author(s):  
L H Thompson ◽  
K W Brookman ◽  
J L Minkler ◽  
J C Fuscoe ◽  
K A Henning ◽  
...  
Keyword(s):  
Sister Chromatid ◽  
Sister Chromatid Exchange ◽  
Human Fibroblasts ◽  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
Repair Gene ◽  
Dna Repair Gene ◽  
Chinese Hamster Cell Line ◽  
Dna Strand ◽  
Repair Defect

The Chinese hamster cell line mutant EM9, which has a reduced ability to repair DNA strand breaks, is noted for its highly elevated frequency of sister chromatid exchange, a property shared with cells from individuals with Bloom's syndrome. The defect in EM9 cells was corrected by fusion hybridization with normal human fibroblasts and by transfection with DNA from hybrid cells. The transformants showed normalization of sister chromatid exchange frequency but incomplete correction of the repair defect in terms of chromosomal aberrations produced by 5-bromo-2'-deoxyuridine.

scholarly journals DNA-mediated transfer of a human DNA repair gene that controls sister chromatid exchange.

1985 ◽  
Vol 5 (4) ◽  
pp. 881-884 ◽  
Author(s):  
L H Thompson ◽  
K W Brookman ◽  
J L Minkler ◽  
J C Fuscoe ◽  
K A Henning ◽  
...  
Keyword(s):  
Sister Chromatid ◽  
Sister Chromatid Exchange ◽  
Human Fibroblasts ◽  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
Repair Gene ◽  
Dna Repair Gene ◽  
Chinese Hamster Cell Line ◽  
Dna Strand ◽  
Repair Defect

The Chinese hamster cell line mutant EM9, which has a reduced ability to repair DNA strand breaks, is noted for its highly elevated frequency of sister chromatid exchange, a property shared with cells from individuals with Bloom's syndrome. The defect in EM9 cells was corrected by fusion hybridization with normal human fibroblasts and by transfection with DNA from hybrid cells. The transformants showed normalization of sister chromatid exchange frequency but incomplete correction of the repair defect in terms of chromosomal aberrations produced by 5-bromo-2'-deoxyuridine.

scholarly journals THE FREQUENCY OF SISTER CHROMATID EXCHANGES FOLLOWING EXPOSURE TO VARYING DOSES OF H3-THYMIDINE OR X-RAYS

1964 ◽  
Vol 21 (2) ◽  
pp. 159-167 ◽  
Author(s):  
G. Marin ◽  
D. M. Prescott
Keyword(s):  
Cell Cycle ◽  
Exchange Rate ◽  
Sister Chromatid ◽  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
Sister Chromatid Exchanges ◽  
X Rays ◽  
Chinese Hamster Cell Line ◽  
Chromatid Exchanges ◽  
Range Of Variation

In the Chinese hamster cell line CHEF-125, sister chromatid exchanges occurred at a rate of a little higher than one per three chromosomes for each cell cycle. The exchanges were detectable by labeling with H3-thymidine and autoradiographic analyses of chromosomes at the second and subsequent metaphases after labeling had occurred. To test the hypothesis that sister chromatid exchanges are caused by radiation, cells were incubated in media with different amounts of H3-thymidine. No statistically significant change in the exchange rate was detected over 100-fold range of variation in the amount of incorporated H3-thymidine (determined by grain counts of autoradiographs). We have concluded that sister chromatid exchanges are not caused by tritium radiation and therefore are spontaneous events. Cultures were also irradiated with acute doses of x-rays up to 200 r and scored for sister chromatid exchanges. Between zero and 50 r there was a statistically significant increase in the rate of exchanges. This is interpreted as evidence that x-rays can induce some exchanges, although the majority of these events are probably spontaneous.

2,4-Dichlorophenol and MCPA in a V79 Test

1988 ◽  
Vol 15 (3) ◽  
pp. 245-250
Author(s):  
Geirid Fiskesjö
Keyword(s):  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
Test System ◽  
Similar Degree ◽  
Human Beings ◽  
Industrial Chemicals ◽  
Allium Test ◽  
Chinese Hamster Cell Line ◽  
A Cell ◽  
Mutagenic Effects

Two industrial chemicals, 2,4-dichlorophenol and 4-chloro-2-methylphenoxyacetic acid (MCPA), which have no toxic effects on the Chinese hamster cell line V79 alone, were tested for toxicity and mutagenicity in a cell-mediated test, where mixed-function oxidase (MFO) enzymes are active in the metabolism of xenobiotics. For 2,4-dichlorophenol, a dose-dependent toxicity as well as a slight mutagenicity could be shown when oxygenation enzymes were present. A similar degree of toxicity in a plant test system (the Allium test) indicates a similar risk of damage from exposure to dichlorophenol treatments in both these systems. MCPA did not induce any toxic or mutagenic effects at the concentrations tested. These results were not in agreement with previous results in plant material, where MCPA was clearly toxic at relatively low doses. However, since chlorophenols have been found in plants sprayed with phenoxyacetic acids, further investigations should be performed concerning potential risk to human beings.

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