Abstract: Objective To investigate the sub-cellular distribution correlation between activated LIMK1 (pLIMK1Thr508) and Aurora-A in mouse oocyte meiosis, and changes in Aurora-A location and spindle structure in condition of LIMK1 inhibition. Methods Immunofluorescence staining was employed to detect the sub-cellular localization of pLIMK1Thr508 and its spatial-temporal correlation with spindle organizing regulator Aurora-A in mouse oocyte meiosis; BMS-3, the specific inhibitor to LIMK1 activity, was applied to analyze the effects of LIMK1 inhibition on Aurora-A distribution and spindle formation. Results At meiotic prophase, pLIMK1Thr508 was weakly detected and concentrated in the germinal vesicle (GV) in oocytes, with no signal of Aurora-A across the cytoplasm and nuclear area; as meiotic assumption approaching, pLIMK1Thr508 left nuclear, aggregating as a single dense dote in the vicinity of nuclear, and being co-localized with the emerging Aurora-A; After germinal vesicle broke down (GVBD), pLIMK1Thr508 and Aurora-A remained overlapped and concentrated as multi foci around the condensed chromosomes; at metaphase I (MI) and metaphase II (MII), pLIMK1Thr508 was co-localized with Aurora-A on spindle poles; During anaphase I (AI) to telophase I (Tel I) progression, pLIMK1Thr508 was detached from spindle poles and mainly concentrated on the cleavage furrow, while Aurora-A loosely congressed on spindle. In addition, LIMK1 inhibition with BMS-3 destroyed Aurora-A polar location and spindle formation. Conclusions pLIMK1Thr508 is a microtubule organizing center (MTOC)-associated protein, may participate in spindle assembly and maintenance through regulating Aurora-A in mouse oocytes during meiotic progression.

Key words: Key words: pLIMK1Thr508, Aurora-A, oocytes, meiosis, spindle