Morpholino knockdown

Wapl-targeting morpholino antisense oligo (Gene Tools, Philomath, OR, USA; 5′-TCTGGATGTCATTTTGACACCTGTT-3′) was diluted with water to provide a working concentration of 1 mM, and then approximately 5 to 10 pl of oligo were microinjected into the cytoplasm of fully grown GV oocytes using a Narishige microinjector (Tokyo, Japan). A nontargeting morpholino oligo (5′-CCTCTTACCTCAGTTACAATTTATA-3′) was injected as a control. To facilitate the morpholino-mediated inhibition of mRNA translation, oocytes were arrested at GV stage in M16 medium containing 2.5 μM milrinone for 20 hours and then cultured in milrinone-free M16 medium for subsequent experiments.