IDENTIFICATION/CHARACTERIZATION OF NOVEL MATERNAL-EFFECT GENE PRODUCTS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 卵母细胞衍生的基因产物控制着卵母细胞向胚胎的转变过程中发生的一系列重要事件，包括第一次减数分裂的完成、第二次减数分裂的启动和胚胎基因组的激活。这些基因产物中只有几种被称为母体效应蛋白，人们对其调节功能的机制知之甚少。通过电子消减，我们发现了几个新的潜在的母性效应基因。在对小鼠和猕猴的基因表达进行初步分析后，我们决定将重点放在一个新描述的蛋白质家族--NLR家族，即含有吡咯域的蛋白(NLRP)上。这个家庭中大多数成员的功能尚不清楚。然而，在啮齿类动物的生殖细胞中发现了几个NLRP基因；其中至少有一个基因NLRP5对小鼠的早期胚胎发育是必不可少的。根据在小鼠身上的发现和我们在猕猴中的初步数据，我们假设卵母细胞特异性的NLRP是卵母细胞成熟、受精和早期胚胎发育所必需的；因此，敲除猕猴卵母细胞中的一个或多个NLRP基因将阻碍卵母细胞向胚胎的转化，导致无法受精的卵子或植入前胚胎的发育停滞。为了进一步研究猕猴卵母细胞特异性的NLRP，我们建议利用体外RNA干扰技术(RNAi)在卵母细胞中证明NLRP蛋白的时空表达并进行功能研究。此外，我们还将建立NLRP基因敲除/敲除小鼠模型，以探索它们在啮齿动物体内的功能。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Oocyte-derived gene products direct a series of crucial events occurring at the oocyte-to-embryo transition, including the completion of the first meiosis, the initiation of the second meiosis, and the activation of the embryo genome. Only a few of these gene products, termed maternal effect proteins, have been identified and little is known about the mechanisms mediating their functions. We identified several novel potential maternal effect genes by in silico subtraction. After initial gene expression analysis in mice and macaques, we decided to focus on a newly described protein family--NLR family, pyrin domain containing protein (NLRP). The function of the majority members in this family is unknown. However, several Nlrp genes are found exclusively in germ cells in rodents; and at least one of them, NLRP5, is essential to early embryo development in mice. Based on previous findings in mice and our preliminary data in macaques, we hypothesize that oocyte-specific NLRPs are required for oocyte maturation, fertilization, and early embryo development; thus, knocking down one or more NLRP genes in the macaque oocyte will impair the progress of oocyte-to-embryo transition, resulting in unfertilizable eggs or developmental arrest of preimplantation embryos. To further characterize oocyte-specific NLRPs in macaques, we propose to demonstrate the spatiotemporal expression of NLRP proteins and perform functional studies using in vitro RNA interference (RNAi) in the oocyte. In addition, we will generate Nlrp gene knockout/knockdown mouse models to explore their in vivo functions in rodents.