Zhang Ling, Li Jie, Su Ping, Xiong Chengliang
Family Planning Research Institute and Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
J Huazhong Univ Sci Technolog Med Sci. 2010 Dec;30(6):781-5. doi: 10.1007/s11596-010-0658-3. Epub 2010 Dec 22.
Brain-derived neurotrophic factor (BDNF) can promote developmental competence in mammalian oocytes during in vitro maturation (IVM), but the role of BDNF in oocyte maturation at cellular level is not still clear. In this study, mouse cumulus-enclosed oocytes subjected to IVM were fertilized and cultured to blastocyst stage. Meiotic spindle configuration and cortical granules distribution during oocyte maturation in vitro were assessed by using immunofluorescence and laser confocal microscopy. The results showed that BDNF contributed to the complete preimplantation development of mouse oocytes compared to the control oocytes (13.78% vs. 5.92%; P<0.05). Further, BDNF did not accelerate nuclear maturation of IVM oocytes. For the BDNF-treated oocytes at meiosis I, Meiotic spindle areas were significantly smaller and the number of cytoplasmic microtubule organizing centers was greater than that in the control, and the percentages of oocytes showed spindles positioned near the oolemma and a well-formed cortical granule-free domain were significantly higher than that of the control. These morphological characteristics of the BDNF-treated oocytes were much closer to the oocytes matured in vivo than those of the control oocytes. In conclusion, BDNF can promote the developmental competence of mouse IVM oocytes, by improving the meiotic spindle configuration and location and cortical granules distribution at meiosis 1.
脑源性神经营养因子（BDNF）在体外成熟（IVM）过程中可促进哺乳动物卵母细胞的发育能力，但BDNF在细胞水平上对卵母细胞成熟的作用仍不清楚。在本研究中，将经历IVM的小鼠卵丘-卵母细胞复合体进行受精并培养至囊胚阶段。通过免疫荧光和激光共聚焦显微镜评估体外卵母细胞成熟过程中的减数分裂纺锤体构型和皮质颗粒分布。结果显示，与对照卵母细胞相比，BDNF有助于小鼠卵母细胞的完整植入前发育（13.78%对5.92%；P<0.05）。此外，BDNF并未加速IVM卵母细胞的核成熟。对于在减数分裂I期经BDNF处理的卵母细胞，减数分裂纺锤体面积显著较小，细胞质微管组织中心的数量多于对照，并且显示纺锤体位于卵周膜附近且形成良好的无皮质颗粒区域的卵母细胞百分比显著高于对照。经BDNF处理的卵母细胞的这些形态特征比对照卵母细胞更接近体内成熟的卵母细胞。总之，BDNF可通过改善减数分裂I期的减数分裂纺锤体构型和位置以及皮质颗粒分布来促进小鼠IVM卵母细胞的发育能力。
