卵母细胞成熟质量低下与1-细胞胚胎发育阻滞是引起动物繁殖障碍的重要因素，TPX2（Targeting protein for Xklp2）是目前体细胞有丝分裂领域的研究热点，但其在卵母细胞向胚胎细胞分裂转化这一特殊进程中的功能尚不明确。本项目拟首先采用激光共聚焦扫描等技术检测TPX2在猪卵母细胞减数分裂向胚胎首次有丝分裂转化进程中的动态表达与亚细胞定位；并通过siRNA干扰与mRNA注射过表达技术研究TPX2对纺锤体组装、染色体分离等事件的调控作用；最后通过特异性阻断与抑制试验研究TPX2是否由上游Ran/importin-β信号分子调控，并通过下游Aurora-A/Plk1激酶通路参与猪卵母细胞向胚胎分裂转化的调控。以期揭示TPX2/Aurora-A/Plk1通路在卵母细胞减数分裂向胚胎首次有丝分裂转化进程中的调控机制，为提高家畜卵母细胞成熟质量、克服早期胚胎发育阻滞提供理论与试验依据。

Low quality of oocyte maturation and 1-cell embryonic development block are the main causes of reproductive failure in animals. TPX2（Targeting protein for Xklp2） is a critical microtubule-associated protein (MAP) that executes a pivotal role in spindle assembly during somatic cell mitosis, however, the possible role of TPX2 in oocyte meiotic progression and embryonic mitotic division is still unclear. The expression and spatiotemporal localization of PTX2 will be assessed initially during the oocyte-to-embryo transition (OET) by Western blotting and confocal microscopy imaging techniques, and the spatiotemporal correlations of PTX2 with microtubules, microfilaments and chromosomes will also be determined. Then the TPX2 expression will be knocked down or overexpression by microinjection of siRNA or mRNA to investigate the specific regulatory roles of TPX2 on the spindle assembly and chromosome separation during oocyte-to-embryo transition. Finally, the importin-β blocker Importazole and Aurora-A/TPX2 interaction inhibito rAurkinA will be used to investigated whether TPX2 is involved in the regulation of downstream Aurora-A/Plk1 kinase pathway, which under the regulation of upstream Ran/importin-β signaling molecules during the oocyte-to-embryo transition. The purpose of this project is to reveal the functional and molecular mechanism of TPX2/Aurora-A/Plk1 signaling pathway during the process of porcine oocytes meiosis-to-embryos first mitosis transition, so as to provide experimental reference for improving the maturation quality of livestock oocytes and overcoming the block of early embryonic development.