蛋鸡卵泡再生和闭锁调控机理的研究

The fecundity of the female poultry depends on the quantity and quality of ovarian follicles. By focusing on follicle regeneration and atresia, this project intends to investigate the mechanisms of two physiological processes including neo-oogenesis /follicular regeneration via germline stem cell (GSC) development and germ cell loss via follicle atresia, for the aim of enhancing the laying performance of hens through both increase of follicle regeneration and attenuation of follicle atresia. The following studies will be carried out: ① separation and identificatiom of GSCs in adult hen ovaries, functions of genes involved in GSC pluripotency maintenance, viability and differentiation together with the underlining mechanisms of regeneration; ② labeling of GSCs with reporter GFP gene through gene transfection, elucidation of GSCs function involved in neo-oogenesis and follicular regeneration as well as the developmental process of germ cells and follicular somatic cells in the renewed follicles; ③ comparison of dynamic follicle atresia in different laying stages and evaluation of the crucial genes in the regulation of follicular atresia to reveal the regulatory mechanisms of germ cell loss; ④ development of measures to enhance follicle regeneration and decrease follicle atresia. The results will facilitate to clarify the regulatory mechanism of hen follicle regeneration and atresia, thus to fully utilize the germ cell reservoir to enhance the laying performance of local breeder hens and commercial layers at the later laying phase.

母禽的繁殖力主要取决于卵巢中卵泡的数量和质量。本项目以蛋鸡卵泡再生和闭锁为主线，研究卵巢在发育中经生殖干细胞发育而发生的卵子新生/卵泡再生和经卵泡闭锁而发生的生殖细胞丢失这两个相反生理过程的调控机理，以期通过促进卵泡新生和减缓卵泡闭锁的双重调控而实现卵泡更新，增强蛋鸡的产蛋性能。研究内容包括：①分离并鉴定成鸡卵巢内生殖干细胞，研究相关基因在生殖干细胞多能性和活性维持及定向分化中的作用,揭示其再生的调控机理；②利用GFP基因转染而标记生殖干细胞，研究其参与卵子新生和卵泡再生的功能以及在新生卵泡中生殖细胞和卵泡体细胞发育的进程；③比较不同产蛋阶段卵巢中卵泡闭锁的动态变化规律，揭示调控卵泡闭锁的主导基因，研究卵泡闭锁和生殖细胞丢失的调节机理；④研究提升成鸡卵泡再生和减缓卵泡闭锁的措施。其结果有助于阐明母鸡卵泡再生和闭锁的调控机理，使生殖细胞库得以充分利用，增强低产蛋鸡和产蛋高峰后期蛋鸡的繁殖力

母禽的繁殖力主要取决于卵巢中可持续发育卵泡的数量和质量。本课题以蛋鸡生殖细胞与体细胞形成卵泡及其后续发育和闭锁为主线，研究卵泡生成和退化两个相反生理过程的调节机理，已完成的研究内容主要包括：① 生殖细胞发育的激素调节，发现FSH和LH可调节卵巢生殖细胞选择有丝分裂或减数分裂，分别实现增殖或分化功能；孕酮通过其膜受体调节生殖细胞减数分裂起始，维甲酸合成酶Raldh2促进RA合成来启动生殖细胞的减数分裂。② 生殖细胞再生能力的检测，在不同阶段成年鸡卵巢中检测到多能性相关的转录因子和减数分裂相关基因的表达，提示成鸡卵巢内仍存在多能性的细胞，并可进行减数分裂。同时，与高增殖活性的小肠干细胞进行了比较研究。③ 比较了不同品种和产蛋阶段卵巢中卵泡发育和闭锁的动态变化规律，以及肝脏中卵黄合成与沉积的变化。④ 建立了不同级别卵泡培养模型和卵巢组织培养模型，为深入研究鸡卵泡发育的调节机理奠定了技术基础。⑤ 卵泡发生及其发育激素调节的研究，研究了多种激素和细胞因子对卵泡发生和发育的调节作用，并探讨了部分信号转导机理。所得结果有助于家禽卵泡发育的调节机理和产蛋性能提升方面的研究。通过以上研究，课题组在Mol Cell Endocrinol、Theriogenology和Poult Sci等专业刊物上发表8篇SCI收录论文。培养博士生8名、硕士生7名。