卵子玻璃化冷冻通过下调PGC7表达影响印记维持的机制研究

玻璃化冷冻是当前有效的配子和胚胎保存技术，但是仍然存在一些问题。相关报道和我们前期研究均发现卵子玻璃化冷冻可导致植入前胚胎及子代印记基因异常，造成潜在的健康风险，本研究前期还发现印记维持关键因子PGC7表达降低，据此推测卵子玻璃化冷冻引起的PGC7表达异常是影响早期胚胎及子代印记维持的重要原因。在前期研究基础上，本项目将首先明确卵子玻璃化冷冻对植入前多个时期胚胎及子代印记基因的影响；之后通过显微注射技术补偿卵子中PGC7的表达，研究植入前胚胎和子代组织中印记基因表达和甲基化改善情况，明确PGC7参与卵子玻璃化冷冻引起的印记基因异常；最后通过微量ChIP-seq技术分析PGC7及其互作蛋白在印记调控区结合的变化，以揭示卵子玻璃化冷冻通过下调PGC7表达影响印记维持的分子机制。本项目旨在揭示卵子玻璃化冷冻影响印记维持的分子机制，为提高卵子冷冻效率和安全性提供理论和试验依据。

Vitrification is currently an effective gamete and embryo preservation technology, but there are still some problems. Relevant reports and our previous studies have found that oocyte vitrification can lead to abnormal gene imprinting in pre-implantation embryos and offspring, causing potential health risks. In the early study, we also found that the expression of the key factor PGC7, which maintains imprint stability, is reduced. Thus, we speculate that the abnormal expression of PGC7 caused by oocyte vitrification is an important factor affecting the imprint maintenance in early embryo and offspring. On the basis of the previous research, this project will first clarify the effect of oocyte vitrification on the imprinting genes in embryos at multiple stages before implantation and offspring; afterwards, the microinjection technique will be used to compensate for the expression of PGC7 in the oocytes and the improvements of imprinted gene expression and methylation in pre-implantation embryos and offspring tissues will be studied to clarify PGC7's involvement in imprinting gene abnormality caused by oocyte vitrification; finally, the changes in the binding of PGC7 and its interacting proteins in the imprinting regulatory region will be analyzed by trace ChIP-seq technology to reveal the molecular mechanism of the oocyte vitrification affecting imprint maintenance by down-regulating PGC7 expression. This project aims to reveal the molecular mechanism of oocyte vitrification affecting the maintenance of imprints, and provide theoretical and experimental basis for improving the efficiency and safety of oocyte vitrification.