DIFFERENTIAL BEHAVIOR OF SISTER NUCLEI IN METHYLXANTHINE-INDUCED BINUCLEATE CELLS

Binucleate cells were induced by treatment with methylxanthines. Nuclear volume increased rapidly in the early part of G1 but the increases were unequal in most pairs of sister nuclei. Treatment with 5-amino-uracil results in increases in nuclear volume; when cells with large nuclei divided they were induced to become binucleate. The sister nuclei of these binucleate cells also showed increases in mean volume and in the mean difference between their volumes. Even though they share the same cytoplasm, sister nuclei behave autonomously in terms of changes in volume. © 1978.