Protein Sumoylation in OOCYTE Development

摘要 女性的生殖寿命从青春期到更年期。然而，在大约1-2%的女性中， 更年期发生，这对健康有负面影响，包括心脏病，骨质疏松， 失血，潮热，甚至早逝在卵泡的非生长池中发现的卵母细胞数量 (the“卵巢储备”），目前认为在很大程度上决定了绝经年龄。因此，过早 如果卵母细胞功能障碍或受损，则出现绝经。小鼠模型表明，卵母细胞特异性 转录因子是卵巢储备内卵母细胞发育所必需的。删除这些 基因，其中包括新生儿卵巢同源异型盒基因（Nobox），导致女性不育和过早丧失 小鼠的卵母细胞。此外，患有卵巢早衰的女性经常在NOBOX中发生突变。 尽管NOBOX是卵母细胞发育所必需的，但关于NOBOX如何作用的信息很少或没有。 功能是规范的。NOBOX的计算机模拟分析确定SUMO化是一种潜在的调控机制。 SUMO化是一种翻译后修饰，控制蛋白质的稳定性、定位和活性， 特别是转录因子。然而，SUMO化在卵巢内卵母细胞发育过程中的作用 发展尚不清楚。因此，我们产生了一种新的卵母细胞特异性敲除Ubc 9，这是一种新的基因敲除方法。 SUMO化级联反应的中心组分。从原始卵泡开始的卵母细胞中Ubc 9的丢失 阶段导致雌性不育和年轻成年小鼠卵母细胞储备的完全耗尽。初步数据 表明SUMO化缺失影响NOBOX功能，表型表现在原发性 次级卵泡期本项目的目的是（1）确定卵母细胞缺陷的原因 在初级卵泡到次级卵泡阶段的发育和（2）阐明SUMO化如何改变卵母细胞- 特异性转录因子功能，导致基因表达改变和卵母细胞死亡/存活。结果 从这些目标将提供深入了解关键卵母细胞特异性转录因子的调控和 卵巢早衰的病因重要的是，这些研究将确立SUMO化作为一种重要的 卵巢内卵母细胞发育的过程。

ABSTRACT Reproductive lifespan in women spans puberty to the menopause. However, in about 1-2% of women, early menopause occurs, and this has negative health consequences, including increases in heart disease, bone loss, hot flashes, or even early death. The number of oocytes found in the non-growing pool of ovarian follicles (the "ovarian reserve"), is currently thought to largely determine the age at the menopause. Thus, premature menopause arises if oocytes are dysfunctional or damaged. Mouse models demonstrate that oocyte-specific transcription factors are required for the development of oocytes within the ovarian reserve. Deletion of these genes, which includes newborn ovary homeobox gene (Nobox), causes female sterility and premature loss of oocytes in mice. Furthermore, women with premature ovarian failure frequently have mutations in NOBOX. Even though NOBOX is required for oocyte development, there is little to no information on how NOBOX function is regulated. In silico analysis of NOBOX identified SUMOylation as a potential regulatory mechanism. SUMOylation is a posttranslational modification that controls protein stability, localization, and activity, particularly for transcription factors. However, the function of SUMOylation during intraovarian oocyte development is not known. Therefore, we generated a novel oocyte-specific knockout of Ubc9, which is a central component of the SUMOylation cascade. Loss of Ubc9 in oocytes beginning at the primordial follicle stage caused female sterility and a full depletion of the oocyte reserve in young adult mice. Preliminary data indicate that loss of SUMOylation affects NOBOX function and the phenotype manifests at the primary to secondary follicle stage. The Aims of this project designed to (1) determine why there are defects in oocyte development at the primary to secondary follicle stage and (2) elucidate how SUMOylation alters oocyte- specific transcription factor function, resulting in altered gene expression and oocyte death/survival. The results from these Aims will provide insight into the regulation of key oocyte-specific transcription factors and the genesis of premature ovarian failure. Importantly, these studies will establish SUMOylation as an essential process in intraovarian oocyte development.