Smad9基因在鹅卵巢卵泡等级建立中的作用

There was characteristics of priority hierarchical follicular development in poultry. the exact regulation mechanism is unknown. For the first time, we found Smad9 genes showed differential expression during goose ovarian development of early stage. In order to further clarify whether Smad9 gene plays a vital role during establishing the follicular hierarchy and whether it is the major gene and key molecular marker genes to control egg performance, this study will be performed to research Smad9 gene spatiotemporal expression patterns and interaction between Smad9 gene and others regulatory factors during establishing the follicular hierarchy. In this study, Sichuan white goose with high egg production and Wanxi white goose with low egg production were selected as materials, siRNA and overexpression, Smad9 gene transfection, immunohistochemistry, real-time PCR, Co-IP, CHIP, and SNPs genotyping technologies were applied in vitro and in vivo and the performance of geese breeding was surveyed. This study will reveal Whether mutations in functional and linker regions regulate gene splicing and expression, and whether Smad9-Smad1 complex bind target genes, regulate transcription and egg performance. This study will help to reveal the molecular regulation mechanism of follicular growth and development of poultry, will provide the theoretical basis for improving laying performance and screening goose molecular genetic markers related with laying performance.

禽类卵泡发育的过程具有优先等级的特点，确切机制不明。本项目组前期研究首次发现Smad9基因参与鹅卵巢的启动过程，在卵巢发育的过程中早期差异表达，成熟期基因沉默。为了进一步明确Smad9基因在卵巢卵泡等级建立过程中的重要作用和作为控制鹅产蛋性能主效基因的有效性，本研究以产蛋量差异较大的皖西白鹅和四川白鹅为例，体内、外应用RNA干扰和过表达技术、免疫共沉淀、染色质免疫沉淀、SNPs分型及其他分子生物学技术，研究Smad9是否通过功能区和连接区变异调节基因剪切和转录水平而影响产蛋量，是否通过与Smad1形成复合物，再结合排卵相关靶基因来调节基因转录和产蛋性能。此研究将有助于揭示禽类卵泡生长发育的分子调控机制，将为提高家禽产蛋性能及筛选与鹅产蛋性状相关的分子遗传标记奠定理论基础，为高产家禽选育开辟新途径。

禽类卵泡发育具有优先等级发育的特点，然而具体机制仍不清楚。BMP/Smads 信号通路在哺乳动物卵泡的发育，卵泡的闭锁与选择过程中发挥极其重要的调控作用，然而该通路中Smad9蛋白的研究鲜见报道。为筛选与鹅产蛋相关的基因，我们对Smad9基因与鹅卵泡等级发育的相关性开展了实验研究，主要从鹅卵泡的组织形态学、Smad9在等级卵泡的表达模式、体内注射Smad9抑制剂、体外诱导鹅卵泡颗粒细胞发育等方面开展了针对Smad9基因功能的研究。结果显示，Smad9在鹅卵巢仅表达于鹅卵泡的颗粒细胞，其在等级卵泡的表达呈现差异表达，注射Smad9抑制剂可以显著促进鹅的产蛋（P<0.05）。体内外研究结果表明Smad9基因在适宜表达条件下可以显著改善鹅体内雌二醇（E2）的分泌和促黄体素受体（LHR）的转录以及颗粒细胞的增殖能力（P<0.05），进而促进卵泡的等级发育和排卵。这一结果为生产上以Smad9抑制剂为基础探索提高禽类产蛋性能提供了新途径。