Preliminary molecular analysis of the TK locus in L5178Y large- and small-colony mouse lymphoma cell mutants.
Mouse lymphoma cells of the L5178Y TK+/- -3.7.2C line were exposed to sidestream and mainstream cigarette smoke condensates (CSC). Cells which survived the trifluorothymidine (TFT) challenge fell in 2 classes: large- and small-colony formers. Southern blot analysis of NcoI-digested DNA from mutant colonies yielded 2 distinct restriction fragment banding patterns when probed with the thymidine kinase (TK) cDNA clone pMtk4. One such pattern was composed of 4 bands at 6.4, 5.5, 4.7 and 2.9 kilobase pairs (kb) and was identical to that of TK+/- controls. A second pattern differed from the first only in the absence of the 6.4-kb band. The majority (83/95) of both large and small colonies derived from cells exposed to CSC exhibited restriction fragment banding patterns lacking the 6.4-kb band. The data from the present study suggest that there is no association between mutant colony size and the presence of the 6.4-kb NcoI restriction fragment at the TK locus in the mouse lymphoma mutants analyzed.
Cobb
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RR
Center for Life Sciences and Toxicology, Chemistry and Life Sciences, Research Triangle Park, NC 27709.
Martin
J
J
Korytynski
E
E
Monteith
L
L
Hughes
T J
TJ
D000818:Animals; D015139:Blotting, Southern; D002874:Chromosome Mapping; D004273:DNA, Neoplasm / Q000032:analysis; D004121:Dimethyl Sulfoxide / Q000633:toxicity; D007940:Leukemia L5178 / Q000235:genetics*; D007942:Leukemia, Experimental / Q000235:genetics*; D051379:Mice; D009152:Mutagenicity Tests; D009154:Mutation; D010947:Plants, Toxic; D012906:Smoke / Q000009:adverse effects; D014026:Nicotiana; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm; D012906:Smoke; D004121:Dimethyl Sulfoxide