Molecular regulation of gene expression and development of mammalian embryos

哺乳动物胚胎从1-细胞期到胚泡期的体外发育被认为是在合子基因激活（ZGA）发生时的物种特征阶段被阻止的。因此，这种发育停滞可能反映了ZGA在体外培养条件下没有得到很好的调节。最近，活性氧（ROS）参与这种发展停滞已被注意到。降低氧分压和向培养基中添加抗氧化剂，如超氧化物歧化酶或硫氧还蛋白，已被证明对胚胎的体外发育产生有益的影响。因此，确定活性氧调节早期胚胎发育的机制非常有趣。最近，人们发现活性氧除了作为氧化应激的第二信使调节细胞生长和分化之外，还具有其他功能。在本研究中，我们尝试定义了氧化还原调节， ...更多信息 小鼠早期胚胎的体外发育。结果表明，核因子κ B（NF-κ B）（一种在细胞氧化还原电位下控制许多基因表达的转录因子）的mRNA和蛋白质在植入前发育过程中在小鼠胚胎中表达，并且NF-κ B在小鼠胚胎的早期1-细胞阶段被阶段特异性激活，此外，NF-kB的激活对于小鼠胚胎发育超过2-细胞期是必需的。在生产识别特异性活化形式的NF-κ B的抗体的实验过程中，我们发现了NF-κ B相关的100 kDa蛋白。该蛋白的克隆实验表明，它是哺乳动物中一种新的前mRNA剪接因子，免疫荧光实验表明，它也在晚期1-细胞小鼠胚胎的细胞核中具有阶段特异性积累。在第二个实验中，我们发现一氧化氮，一种自由基分子作为发育的调节剂，特别是2-细胞胚胎向4-细胞阶段的过渡和囊胚的形成。因此，这表明，在植入前阶段，特别是在ZGA和囊胚形成时期，胚胎的发育和基因表达受到氧化还原调控。少

In vitro development of mammalian embryos during preimplantation period from the 1-cell to the blastocyst stages is known to be arrested at a stage characteristics for the species when zygotic gene activation (ZGA) occurs. This developmental arrest might, therefore, reflect a ZGA that is not well-regulated under in vitro culture conditions. Recently, involvement of reactive oxygen species (ROS) in this developmental arrest has been noted. Lowering oxygen tension and the addition of anti-oxidants, such as superoxide dismutase or thioredoxin, to the culture medium has been shown to exert a beneficial effect on in vitro development of embryos. Thus, it is much of interest to define the mechanisms by which early embryonic development is regulated by ROS.Recently, it has become clear that ROS have additional functions besides oxidative stress as second messengers for regulation of cell growth and differentiation. In the present studies, attempts were made to define the redox regulation in i … More n vitro development of early mouse embryos. As the results, it was shown that the mRNA and protein of nuclear factor kappa B (NF-kB), a transcription factor that controls the expression of a number of genes under cellular redox potentials, are expressed in mouseembryos during preimplantation development, and NF-kB is stage-specifically activated at early 1-cell stage in mouse embryos, and moreover that the activation of NF-kB is essential for the development of mouse embryos beyond the 2-cell stage. During the course of experiments on the production of antibodies that recognize specifically activated form of NF-kB, we found NF-kB-related 100 kDa protein. Cloning experiments of the protein revealed that it is a novel pre-mRNA splicing factor in mammals, and immunofluorescense experiments revealed that it is also stage -specifically accumulated in the nuclei of late 1-cell mouse embryos. In the second experiments, we found that nitric oxide, a free radical molecule acts as a regulator of development, especially transition of 2-cell embryos to the 4-cell stage and formation of blastocysts. Thus, it is indicated that the development and gene expression of embryos during preimplantation stages, especially at periods of ZGA and blastocyst formation are regulated under redox controls. Less