CENTROMERES REPOSITION TO THE NUCLEAR PERIPHERY DURING L6E9 MYOGENESIS IN-VITRO

To test the hypothesis that genome architecture in interphase is relat ed to nuclear function, we have compared the disposition of centromere s in nuclei of undifferentiated rat L6E9 myoblasts with that in nuclei of LEES myotubes differentiated in vitro. Immunofluorescence labeling showed that centromeres repositioned to the nuclear periphery during differentiation, and condensed chromatin was more prominent at the myo tube nuclear envelope by electron microscopy. These data indicate that , in parallel with considerable changes in gene expression, the spatia l order of the genome undergoes substantial rearrangement during myoge nesis. (C) 1996 Academic Press, Inc.