母源因子LRP6通过调控Wnt/β-catenin信号通路影响囊胚形成潜能的分子机制研究

辅助生殖治疗中，人类囊胚发育率仅有40~60%。卵母细胞中的母源基因对早期胚胎发育有重要调控作用，鉴定并研究其机制，对揭示胚胎发育阻滞具有重要意义。申请人前期通过对比能否发育到囊胚的8-cell期人类胚胎转录组发现，母源基因LRP6的表达水平在阻滞组明显升高。作为Wnt信号通路的重要配体，LRP6调控胚胎发育及囊胚形成的机制还有待深入挖掘。本课题拟通过对基因表达的定量分析、干扰及荧光示踪等技术，系统研究：1）小鼠卵母细胞及不同发育阶段胚胎中Lrp6的表达对囊胚形成的影响；2）通过干扰胚胎母胎转换过程中Wnt信号通路的调控，研究其在母源基因降解过程中的作用，解析Wnt/Lrp6通路对胚胎发育调控的分子机制；3）使用临床废弃的人类胚胎进行验证，探究Wnt/LRP6通路对囊胚形成的调控机制。该课题将有助于加深母源基因对囊胚形成作用机制的理解，为临床筛选优质胚胎及提高辅助生殖治疗成功率提供新思路。

During assisted reproduction treatment process, the rate of human blastocyst development is only about 40~60%. It has been proved that maternal genes in oocytes played an important role in the regulation of early embryonic development. Identifying important maternal genes and studying their mechanisms are of great significance for revealing embryonic developmental retardation. The applicant found that the expression level of LRP6 was significantly increased in the arrested embryos by comparing the 8-cell embryo transcriptome of whether it could form into blastocyst. As an important ligand of the Wnt signaling pathway, the mechanism by which LRP6 regulates embryonic development and blastocyst formation remains to be explored. Therefore, this project intends to use quantitative analysis, gene interference and fluorescence tracing techniques to systematically study: 1) the effect of Lrp6 expression at different developmental stages in mouse embryos and oocytes on the formation of blastocysts; 2) during the maternal to zygotic transition process, focus on the role of the process of maternal gene degradation and the molecular mechanism of the embryonic development process by interfered the expression of Wnt/Lrp6 signal pathway through external sources; 3) using clinically discarded human embryos to verify and explore the regulating mechanism of Wnt/LRP6 pathway for blastocyst formation. We expect to clarify the influence of LRP6 on the potential of blastocyst formation and provide new ideas for clinical screening of high-quality embryos and as well as improving the success rate of assisted reproduction therapy.