Dynein promotes porcine oocyte meiotic progression by maintaining cytoskeletal structures and cortical granule arrangement

ABSTRACTCytoplasmic dynein is a family of cytoskeletal motor proteins that move towards the minus-end of the microtubules to perform functions in a variety of mitotic processes such as cargo transport, organelle positioning, chromosome movement and centrosome assembly. However, its specific roles during mammalian oocyte meiosis have not been fully defined. Herein, we investigated the critical events during porcine oocyte meiotic maturation after inhibition of dynein by Ciliobrevin D treatment. We found that oocyte meiotic progression was arrested when inhibited of dynein by showing the poor expansion of cumulus cells and decreased rate of polar body extrusion. Meanwhile, the spindle assembly and chromosome alignment were disrupted, accompanied by the reduced level of acetylated α-tubulin, indicative of weakened microtubule stability. Defective actin polymerization on the plasma membrane was also observed in dynein-inhibited oocytes. In addition, inhibition of dynein caused the abnormal distribution of cor...