针对钼提高卵母细胞发育潜能，诱导MMPs表达，影响胚胎植入这一前期研究结果，本项目拟构建绵羊胚胎与子宫内膜上皮细胞共培养体系，并借助逆转录病毒载体pLVX构建MMP-2/MMP-9过表达胚胎。通过在培养液中添加不同剂量钼，在胚胎发育的不同阶段，借助实体显微镜观察胚胎的黏附及扩展情况；采用ELISA和明胶酶谱法分析培养液中MMPs前体含量及MMPs活性；利用real-time PCR、免疫组化和Western-blot等技术检测共培养体系MMPs/TIMPs系统相关基因表达情况，研究钼调控胚胎与子宫内膜上皮细胞共培养体系的量效时效关系。同时利用体外受精-胚胎移植模型，对照体外共培养体系研究内容，探索钼对围植入期绵羊子宫内膜母胎界面MMPs/TIMPs系统的影响。从发育生物学角度，研究钼诱导MMPs/TIMPs系统调控绵羊胚胎植入的分子机制，为保障雌性动物生殖健康及促进畜牧业发展提供理论支持。

Based on the previous research results that molybdenum can improve oocyte development potential, induce MMPs expression and affect embryo implantation, a co-culture system of sheep embryos and endometrial epithelial cells will be constructed and the over-expressed embryos of MMP-2/MMP-9 will also be constructed by retroviral vector pLVX. The different doses of molybdenum are add into the culture medium, the adhesion and expansion of embryos are observed with solid microscopy and MMPs precursor content and MMPs activity in culture medium were measured though ELISA and gelatin zymography at different stages of embryonic development. The expression of genes related to MMPs/TIMPs system in co-culture system is detected by real-time PCR, immunohistochemistry and Western-blot to study the dose-effect-time relationship between molybdenum regulating embryo and endometrial epithelial cell co-culture system. Meanwhile, the effect of molybdenum on the mRNA and protein expression of genes related to MMPs/TIMPs system at the peri-implantation maternal-fetal interface of sheep was detected with the vitro fertilization-embryo transfer model. The molecular mechanisms of molybdenum-induced MMPs/TIMPs system regulating sheep embryo implantation are elucidated from the perspective of developmental biology and provided theoretical support for ensuring reproductive health of female animals and promoting the development of animal husbandry.