Regulation of B cell apoptosis during the cell cycle.

The Ramos-Burkitt lymphoma (J3L) B cell line can be driven into apoptosis by a number of stimuli including antibody (antiIgM) dincted against the antigen receptor (AgR) [l]. In order to generate a synchronised population of cells prior to detennining their response to AgR ligation, we have used two separate agents hydroxyurea and nocodazole. Hydroxyurea induces arrest through inhibition of ribonuclease reductase at the G1 phase of the cell cyck prior to S phase, whereas nocodazole inhibits microtubule formation and arrests cells at the CQM boundary.