Chromosome 11 Aberrations in Small Colony L5178Y TK-/-Mutants Early in Their Clonal History

摘要

The authors have developed a cytogenetic technique that allows observation of chromosome rearrangements associated with TK-/- mutagenesis of the L5178Y/TK+/-3.7.2C cell line early in mutant clonal history. For a series of mutagenic treatments they show that the major proportion (93%) of small-colony (omega) mutants studied have chromosome 11 rearrangements (the chromosome containing the thymidine kinase gene) while large-colony (lambda) mutants do not have detectable chromosome rearrangements. In addition, the authors find among the chromosome abnormalities in omega mutants a significant proportion (34%) with dicentric chromosomes involving chromosome 11. These potentially unstable chromosome rearrangements may help to explain the karyotypic instability and heterogeneity among chromosome 11 aberrations previously noted in omega mutants when they are analyzed later in their clonal history.