Fig. 6. Inhibition of importin ß-mediated nuclear transport inhibits pronucleus formation and prolongs Ca²⁺ oscillations. Oocytes were injected with dominant-negative importin ß^45-462 and fertilized to record the effects of inhibition of nuclear transport on Ca²⁺ oscillations at fertilization. Importin ß^45-462-injected eggs continued oscillating for nearly 12 hours, whereas controls stopped after 4 hours (P<0.01).