miRNAs 调控优势卵泡选择及其影响小卵泡发育的分子机制

The selection of a dominant follicle, a crucial event during folliculogenesis, is precisely regulated by hormones, cytokines and growth factors as well as the dialogue between oocyte and granulosa cells. However, it remained largely unknown regarding the transcriptional regulatory mechanism, via which various signaling molecules and functional genes are spatiotemporally activated or silenced. In this respect, miRNAs as central posttranscriptional gene regulatory factor, are likely to be potential vital players during the selection of dominant follicle. To address how miRNAs participate in regulating the process of dominant follicle selection and the dominant follicle selection on the development of small follicle, we will employ natural cycle IVF combined with in vitro maturation of immature oocyte (IVF/IVM) model as well as human clinical follicular fluids and granulosa cells under this model, to accordingly investigate the differential expression of miRNAs in follicular fluid of dominant follicle and small follicles by Solexa deep sequencing, and the specific miRNAs were further validated by quantitative RT-PCR. After targeted gene prediction, the main function and significant differential gene pathways were analyzed to establish the regulation network of target gene. Following these, based on the culture of granulose cells, to explore the function and corresponding target gene for the selected differentially expressed miRNAs. It is hoped that a better understanding on posttranscriptional regulatory aspects of dominant follicle selection on the development of small follicles will help us to reveal the differences between in vitro matured oocytes and in vivo matured oocytes and to help us to improve the IVM efficiency.

哺乳动物优势卵泡选择是卵泡发育过程中的关键环节，受激素、细胞因子和生长因子以及卵母细胞与颗粒细胞交互作用的精确调控，但优势卵泡选择过程特异性开启与关闭的转录机制远未阐明。我们推测miRNAs作为转录后调控因子可能在优势卵泡选择对小卵泡发育的影响中起重要的转录调控作用，提出关键科学问题“miRNAs调控优势卵泡选择影响小卵泡发育的分子机制是什么”，拟利用自然周期IVF/IVM技术为模型，用Solexa2代深度测序技术建立优势卵泡和小卵泡卵泡液miRNA表达谱，对比找出差异表达的miRNAs；结合qRT-PCR验证这些差异miRNAs的存在，确定与优势卵泡选择和/或小卵泡发育相关的miRNAs；最后以卵丘颗粒细胞为模型，研究相应miRNAs的功能及相应的靶基因，力争揭示优势卵泡选择对小卵泡发育影响的miRNAs转录调控分子机制，为实现无创性预测卵母细胞质量的关键生物学标志提供理论基础和新思路。

哺乳动物优势卵泡选择是卵泡发育过程中的关键环节，受激素、细胞因子和生长因子以及卵母 细胞与颗粒细胞交互作用的精确调控，但优势卵泡选择过程特异性开启与关闭的转录机制远未阐明。我们推测miRNAs作为转录后调控因子可能在优势卵泡选择对小卵泡发育的影响中起重要 的转录调控作用，提出关键科学问题“miRNAs调控优势卵泡选择影响小卵泡发育的分子机制是 什么”，拟利用自然周期IVF/IVM技术为模型，力争揭示优势卵泡选择对小卵泡发育影响的miRNAs转录调控 分子机制，为实现无创性预测卵母细胞质量的关键生物学标志提供理论基础和新思路。. 2015上半年我们发现，对自然周期优势卵泡和小卵泡卵泡液中miRNAs表达差异检测的意义在于自然周期 IVF/IVM 技术的临床应用价值。如果自然周期 IVF/IVM技术在实践上实施受限或有阻碍，那么 miRNAs 检测就失去了临床意义。为此，我们首先检测了女性月经周期中FSH、LH、E2、P、Inhibin A 和 Inhibin B 的激素水平，；然后，检测了同一卵巢中优势卵泡和小卵泡中的激素浓度。随后，探讨了卵泡液中抗苗勒管激素(AMH)水平对卵母细胞发育、受精和卵裂的影响。这些基础研究结果为我们下一步的工作奠定了坚实的基础。. 那么，由未成熟卵母细胞体外成熟后获得的胚胎与促排卵方案获得的胚胎在染色体方面究竟有无差异？如果没有，那我们以上的结果将是自然周期技术得到临床应用的关键结果。2015年，我们利用成功分娩的自然周期 IVF/IVM 技术和控制性促排卵技术患者的剩余胚胎，经过其知情同意，采用MALBAC 技术，进行了胚胎高通量全基因组测序。共对178枚胚胎进行了检测， 发现63个染色体异常，3个扩增异常，胚胎染色体异常比例为36.%（63/175）。自然周期未成熟卵母细胞得到的胚胎与传统促排卵技术得到的胚胎在染色体异常方面无显示差异。同时也从另一方面得到了自然周期IVF/IVM技术在安全性应用的一个有力证据。..