雌性动物在出生之后，卵巢上的卵原细胞及其发育形成的原始卵泡数量已经确定。卵泡池维持时间决定了雌性动物一生的繁殖寿命和繁殖性能，而原始卵泡激活的进程决定了卵泡池消耗的速度。在小鼠的研究表明，细胞核内的转录因子Foxo3抑制卵泡激活，磷酸化之后被转运到胞质中，抑制作用解除而卵泡发生激活。目前，人们对禽类卵泡激活涉及的调控因子及其机制知之甚少。在本研究中，我们将通过原始生殖细胞介导制备转基因鸡，实现Foxo3 表达沉默或过表达磷酸化位点缺失的Foxo3，探索该基因在鸡卵泡激活过程中所发挥的具体作用和调控机制，研究结果将对指导繁殖育种提高产蛋性能、促进以禽类为模型研究生殖和发育相关问题具有重要参考意义。

There are fixed number of oogonia and the derived primordial follicles on the female ovary after birth. The reproductive life and performance is determined by the maintenance of the follicle pool, which is depleted by a process called follicle activation. Research in mouse demonstrated that follicle activation is inhibited by a transcription factor Foxo3 located in cellular nucleus. The inhibitive effect is removed while the Foxo3 is phosphorylated and transported to cytoplasm. Currently, little is known about the factors and mechanism underlined the follicle activation in chicken. In this study, Foxo3 will be silenced or a mutant Foxo3 without phosphorylation sites will be expressed in transgenic chicken produced by primordial germ cell transplantation. And the role of Foxo3 in follicle activation and its regulation network will examined in chicken. The result of the study will be helpful for us to improve the reproductive performance of laying hens and also facilitate the use of avian model to understand the reproductive physiology and development.