Aphidicolin-induced Endoreduplication in Chinese Hamster Cells

Abstract

Aphidicolin, a specific inhibitor of DNA polymerase α, was found to induce high frequencies of endoreduplication in Chinese hamster V79 cells in a dose-dependent manner. The aphidicolin-induced endoreduplication was observed when cells were incubated at 37° but not at 41°. Since it is known that DNA polymerase β is more thermally labile than is DNA polymerase α, the data are consistent with the hypothesis that DNA polymerase α might be responsible for endoreduplication as was reported in mouse trophoblast cells. From the induced diplochromosomes, it was observed that the two unifilarly 5-bromodeoxyuridine-substituted chromatids are generally paired and located inside, whereas the two bifilarly 5-bromodeoxyuridine-substituted chromatids are flanking outside regardless of the presence of sister chromatid exchange or intradiplochromatid interchange.