Characterization of a mutator gene in Chinese hamster ovary cells

摘要: Abstract We have recently reported the isolation of a class mutants (called thy-) that is both resistant to arabinosyl cytosine and auxotrophic for thymidine. thy- 5- 10-fold elevated pool dCTP are deficient in synthesis dTTP as an apparent consequence single mutation gene ribonucleoside-diphosphate reductase (2'-deoxyribonucleoside-diphosphate:oxidized-thioredoxin 2'-oxidoreductase, EC 1.17.4.1). Here we show three independent lines 50-fold higher frequency rate spontaneous two genetic markers, 6-thioguanine resistance ouabain resistance. The site specific because other reversion proline auxotrophy prototrophy emetine resistance, unaffected. Ouabain- 6-thioguanine-resistant mutations occur at much lower revertants wild-type state, so increased mutation. Both mutational intracellular pools dominant or codominant hybrid cells, alterations ratio 49 produce corresponding changes Thus, mutator Chinese hamster ovary apparently imbalance deoxynucleoside triphosphate created by expanded dCTP.