In transgenic mice, self-reactive B lymphocytes are elimlnated if they encounter membrane-bound self antlgene during their development within the bone marrow. We show here that two separate and sequential events, arreated development and cell death, bring about B cell elimination. Developmental arrest is an early outcome of antlgen binding in immature B ceils, blocks acguisition of adhesion molecules and recep tors important for B cell migration and activation, and is rapidly reversible by removal of antigen. Death of the arrested B cells occurs within 1 to 3 days and can be detayed by expression of a M-2 tranegene, which results in e8cape of large number8 of self-reactive B cells from the bone marrow but fails to override the devefopmental arrest. These flndlngs define a novel pathway for Bcall ellmlnatlon, involving an initial stage vulnerable to breakdown in autoimmune disease.