BEHAVIOR OF MITOTIC APPARATUS AFTER UV-MI CROIRRADIATION OF THE SPINDLE POLE

UV-microirradiation of the centrosome (spindle pole) alters behaviour of mitotic cell. Cell reaction strongly depends on the stage of mitosi s when irradiation has been made. Irradiation of one pole at metaphase blocked cell in c-mitosis for several hours. The same or even more st rong irradiation of the pole at anaphase slightly postponed cytokinesi s, but didn't prevent chromosome separation and normal exit of cell in to interphase. Irradiation at metaphase resulted in immediate shift of chromosomes towards the nonirradiated pole. Afterwards spindle disass embled. Irradiation at anaphase slowed down chromosome motion towards irradiated pole without prominent effect on the opposite halfspindle. Electron microscopy demonstrated that immediately after irradiation ce ntrosome lost association with kinetochore microtubules. At metaphase irradiated pole moved towards chromosomes, while at anaphase - away fr om them. Same irradiation of other besides spindle poles regions had n o effect on continuation of mitosis.