Sun Min, Li Zhi, Gui Jian-Fang
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Wuhan, China.
J Exp Zool A Ecol Genet Physiol. 2010 Oct 1;313(8):461-73. doi: 10.1002/jez.618.
Spindlin (Spin) was thought as a maternal-effect factor associated with meiotic spindle. Its role for the oocyte-to-embryo transition was suggested in mouse, but its direct evidence for the function had been not obtained in other vertebrates. In this study, we used the CagSpin-specific antibody to investigate CagSpin expression pattern and distribution during oogenesis of gibel carp (Carassius auratus gibelio). First, the oocyte-specific expression pattern and dynamic distribution was revealed in nucleoli, nucleoplasm, and spindle from primary oocytes to mature eggs by immunofluorescence localization. In primary oocytes and growth stage oocytes, CagSpin accumulates in nucleoli in increasing numbers along with the oocyte growth, and its disassembly occurs in vitellogenic oocytes, which implicates that CagSpin may be a major component of a large number of nucleoli in fish growth oocytes. Then, co-localization of CagSpin and β-tubulin was revealed in meiotic spindle of mature egg, indicating that CagSpin is one spindle-associated factor. Moreover, microinjection of CagSpin-specific antibody into the fertilized eggs blocked the first cleavage, and found that the CagSpin depletion resulted in spindle assembly disturbance. Thereby, our study provided the first direct evidence for the critical oocyte-to-embryo transition function of Spin in vertebrates, and confirmed that Spin is one important maternal-effect factor that participates in oocyte growth, oocyte maturation, and oocyte-to-embryo transition.
纺锤体素（Spin）被认为是一种与减数分裂纺锤体相关的母体效应因子。在小鼠中已表明其在卵母细胞向胚胎转变过程中的作用，但在其他脊椎动物中尚未获得其功能的直接证据。在本研究中，我们使用CagSpin特异性抗体来研究纺锤体素在银鲫（Carassius auratus gibelio）卵子发生过程中的表达模式和分布。首先，通过免疫荧光定位揭示了从初级卵母细胞到成熟卵子的核仁、核质和纺锤体中卵母细胞特异性的表达模式和动态分布。在初级卵母细胞和生长阶段的卵母细胞中，随着卵母细胞生长，CagSpin在核仁中积累的数量不断增加，并且在卵黄发生期的卵母细胞中发生解聚，这表明CagSpin可能是鱼类生长卵母细胞中大量核仁的主要成分。然后，在成熟卵子的减数分裂纺锤体中揭示了CagSpin与β-微管蛋白的共定位，表明CagSpin是一种与纺锤体相关的因子。此外，向受精卵中显微注射CagSpin特异性抗体阻断了第一次卵裂，并且发现CagSpin的缺失导致纺锤体组装紊乱。因此，我们的研究为纺锤体素在脊椎动物中关键的卵母细胞向胚胎转变功能提供了首个直接证据，并证实纺锤体素是参与卵母细胞生长、卵母细胞成熟以及卵母细胞向胚胎转变的一个重要母体效应因子。
