Abstract
At a nonpermissive temperature, premature chromosome con-densation is induced in the temperature-sensitive mutant from BHK21, tsBN2 (4). We fused tsBN2 cells that showed premature chromosome condensation with interphase tsBN2 cells and found that premature chromosome condensa-tion was induced in the interphase nuclei. This suggests that a "chromosome condensing factor(s)" which has been known as a mitotic factor(s) (1, 2) is produced in tsBN2 cells that have premature chromosome condensation.
