A HIGH-YIELD OF TRANSLOCATIONS PARALLELS THE HIGH-YIELD OF SISTER-CHROMATID EXCHANGES IN THE CHO MUTANT EM9

The fluorescence plus Giemsa (FPG) and fluorescence in situ hybridizat ion (FISH) techniques have been used to determine, respectively, the f requencies of sister chromatid exchanges (SCEs) and stable chromosome aberrations (translocations) induced by different concentrations of Br dU in the Chinese hamster ovary cell mutant EM9 and its parental line AA8. The results indicate that BrdU induced a high frequency of SCEs a nd translocations in EM9 as compared with AA8, and that the translocat ion/dicentric ratio was also higher in the mutant cell line than in th e parental cell line in both untreated and BrdU-treated cultures. Thes e observations may indicate a possible relationship between the molecu lar mechanisms involved in the formation of SCEs and translocations. ( C) 1998 Elsevier Science B.V.