Abstract: Embryonic diapause is a survival strategy and reproductive state that is widespread in mammals. It starts prior to implantation when embryo development is minimized or put on hold, and terminates when embryo development is reactivated. Embryonic diapause is supposed to be reversible and harmless to the subsequent embryo development and it has two types:facultative diapause and obligate diapause. Facultative diapause is activated by lactation whereas obligate diapause is activated by seasonal photoperiod. The entrance, maintenance, and reactivation of embryonic diapause are all regulated by the relative levels of prolactin, progesterone, or ovarian estrogen. In addition to hormone regulation, the molecular mechanisms of embryonic diapause have been studied in several mammal species. A large number of potential factors that could regulate embryonic diapause were reported, including nutrients, proteases, cytokines, growth factors and transcription factors. In the present study, we reviewed previous studies on embryonic diapause, summarized current knowledge, and then proposed some scientific suggestions for further research needed on this topic.

Key words: Embryonic diapause, Mammals, Hormone regulation, Molecular mechanisms

摘要： 胚胎滞育（Embryonic diapause）是存在于部分哺乳动物中的一种生存策略和繁殖状态。其具体过程为：胚胎在着床前停止或减缓发育形成胚胎滞育期，滞育期结束后胚胎再次活化，且滞育过程不会对随后的胚胎发育产生任何不良影响。胚胎滞育主要分为两种类型：兼性滞育（Facultative diapause）和专性滞育（Obligate diapause）。兼性滞育受哺乳调控，专性滞育受季节性光周期调控。虽然滞育原理各不相同，但哺乳动物的滞育过程都是在催乳素、孕酮或者卵巢雌激素的共同调节下完成的。除激素调控机制外，胚胎滞育的分子调控机制研究也有了实质性进展，目前已发现了大量能够调节胚胎滞育的潜在候选因子，包括营养物质、蛋白酶、细胞因子、生长因子和转录因子等。本文对现有胚胎滞育研究做了归纳和整理，同时针对胚胎滞育研究现状提出几点建议，为以后胚胎滞育研究提供参考。

关键词: 胚胎滞育, 哺乳动物, 激素调控, 分子调控