Induction of prematurely condensed chromosomes by mitoplasts

The objective of this study was to obtain pure prematurely condensed chromosomes (PCC) by a fusion between mitoplasts and interphase G1 cells. The stabilization of mitoplasts with spermine (25 microM) and a modification of the Sendai virus-mediated fusion enabled us to obtain pure PCC without contaminating mitotic chromosomes. This study clearly suggests that the factors for premature chromosome condensation induction are present in the cytoplasm of the mitotic cells. Pure PCC obtained by this method may help us to understand the nature of the factors initiating chromosome condensation and cell division.