Studies on endoreduplication. III. Endoreduplication induced by mitomycin C in PHA-stimulated tonsillar lymphocyte cultures.

The activity of mitomycin C (MMC) to induce endoreduplication was examined in PHA-stimulated tonsillar lymphocyte cultures. Cellular kinetics of both diploid and endoreduplicated cells was studied by the combined techniques of thymidine and BrdU incorporation. The kinetic data showed that the increase of endoreduplicated cells induced by MMC correlated with the increase of the second-generation diploid cells. Also, it showed that the majority of endoreduplicated cells found at the time when the maximal number of endoreduplicated cells was obtained had incorporated BrdU only once into their diplochromosomes. This suggests that MMC-induced endoreduplicated cells originate from MMC-induced G2-arrested cells.