ANALYSIS OF RELATIONSHIP BETWEEN PROGRAMMED CELL-DEATH AND CELL-CYCLEIN LIMB-BUD

Programmed cell death plays a crucial role in limb morphogenesis of am niote. In this paper, we showed that cell cycle and cell death in limb -buds were closely related events and there existed a critical S-phase , which corresponded to the most sensitive time for inhibition of cell death following administration of an excess dose of 5-bromodeoxyuridi ne (BrdU). The use of microfluorometry of BrdU incorporation coupled w ith measurement of DNA amount of individual cells enabled us to consid er that cells committed to die were withdrawn from cell cycle at G2-ph ase. Finally, we will summarize the nuclear events involved in apoptos is in limb morphogenesis in relation to cell cycle.