Spindlin1(Spin1), a meiotic spindle-binding protein that is highly expressed in cancer cells. Spindle-binding was dependent on its phosphorylation status, which was partially regulated by Mos/MAP kinase pathway. Nevertheless, the biologic roles of Spin1 in oocytes maturation are still largely unknown. For exploring the function of Spin1 in porcine oocyte maturation, Knockdown and overexpression methods were employed to the present study. Spin1 mRNA were enriched in maternal stages, from germinal vesicle - to 2 cell - stage, but sharply decreased after 4 cell stage, zygotic genome activation. Protein of SPIN1 was localized in spindle-chromatin complex during the metaphase I and metaphase II stages. Knockdown of Spin1 did not affect the first polar body extrusion, however, Spin1 depletion caused mitotic spindle defects, chromosome instability and pronuclear formation in metaphase II stage. Percentage of 2cell, 4cell embryos and blastocyst formation were significantly reduced in knockdown group compared with control, but cell numbers in blastocyst were no difference between control and knockdown groups. Another hand, Oocyte failed to maturation and induced metaphase I arrest following Spin1 over-expression. In conclusion, Spin1 is involved in the spindle formation and maintenance during oocytes meiotic maturation in pigs.

• Jeong-Woo Choi
• Kyung-Tae Shin(Department of Animal Science, Chungbuk National University)
• Nam-Hyung Kim(Department of Animal Science, Chungbuk National University)
• Xiang-Shun Cui(Department of Animal Science, Chungbuk National University)