IDENTIFICATION/CHARACTERIZATION OF POTENTIAL NOVEL MATERNAL-EFFECT GENE PRODUCTS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。卵母细胞衍生的母体效应蛋白指导了卵母细胞向胚胎转变过程中发生的一系列关键事件，包括第二次减数分裂的完成、第一次有丝分裂的开始和胚胎基因组的激活。很少有母性效应蛋白被鉴定出来，而介导其功能的机制也知之甚少。本研究的目的是鉴定和表征新的潜在的母系效应基因。利用硅片减法，我们在小鼠中鉴定了四个新基因，分别命名为xw13、xw44、xw46和xw47。基于这些mrna的时空分布，我假设这四个新基因编码小鼠卵母细胞向胚胎转变所需的母体效应蛋白。设计了两个特定的目标：目标1，表征这些新基因编码的基因产物。我们将针对这四种新推导的蛋白产生特异性抗体，以表征它们在小鼠组织和早期胚胎中的蛋白结构和表达，并鉴定它们在非人灵长类动物和人类中的同源基因；目的2，阐明新基因产物在体外卵母细胞向胚胎转变中的功能意义。应用体外RNAi和转基因方法在小鼠卵母细胞和早期胚胎中，我们将研究新基因产物在卵母细胞成熟、受精和早期胚胎发生中的潜在功能。在人类中，大约50%的妊娠丢失与着床前缺陷有关。因此，对母体效应蛋白的研究将为发现可能与人类特发性不孕症有关的基因产物提供关键见解。

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 maternal-effect proteins direct a series of crucial events occurring at the oocyte-to-embryo transition, including the completion of the second meiosis, the initiation of the first mitosis, and the activation of the embryonic genome. Few maternal-effect proteins have been identified and little is known about the mechanisms mediating their functions. The goal of this research is to identify and characterize novel potential maternal-effect genes. Using in silico subtraction, we have identified four novel genes named xw13, xw44, xw46 and xw47 in mice. Based on the spatial and temporal distribution of these mRNAs, I hypothesize that the four novel genes encode maternal effect proteins that are required for the oocyte-to-embryo transition in mice. Two specific aims are designed: Aim 1, characterization of gene products encoded by these novel genes. We will generate specific antibodies against the four novel deduced proteins to characterize their protein structure and expression in mouse tissues and early embryos, and identify their orthologs in nonhuman primates and humans; Aim 2, elucidation of the functional significance of the novel gene products in the oocyte-to-embryo transition in vitro. Applying in vitro RNAi and transgene methodologies in mouse oocytes and early embryos, we will study the potential functions of the novel gene products during oocyte maturation, fertilization, and early embryogenesis. Approximately 50% of pregnancy loss is associated with preimplantation defects in humans. Thus, the studies on maternal effect proteins will provide key insights into possible gene products that are implicated in idiopathic human infertility.