Analysis of Imprinted Genes Expressed in the Brain.

大脑中表达的印记基因的分析。

基本信息

批准号：
08680703
负责人：
KANEKO-ISHINO Tomoko
金额：
$ 1.6万
依托单位：
Tokai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08680703/
关键词：
Imprinting DNA binding protein Neuronatin Immunostaining PEG3 Glyoma Tumor supressor gene Placenta Hypothesis

项目摘要

Paternally expressed genes 3 (Peg3) and 5 (Peg5), which were identified by our systematic screening of imprinted genes using a novel subtraction-hybridization method, are expressed in adult brain specifically. Peg3 encodes a large C2H2 type zinc finger protein, presumably functioning a novel DNA binding protein. Peg5 was idenfied with Neuronatin which was reported to be expressed firstly in rhombomere 3 and 5 at day 8.5 embryos and later in central nervus system. Using in situ hybridization technique, immuno-staining with specific antibodies, we demonstrated that Peg3 protein localized in nucleus of neuronal and glial cells in the adult brain. We also demonstrated that human PEG3 gene suppressed the tumorigenecity of glioma cells by introducing a complete PEG3 cDNA into the cells. These results suggested that PEG3 protein fuctions as a DNA binding protein and controls several genes functioning in cell cycles, and as a result acts as tumor suppressor in glial cells.Systematic analysis of in situ hybridization of the imprinted genes we have isolated showed that the expression pattems in early embryos were divided to three groups, mesoderm specific, neural tissue specific and very low expression in the embryos. However, all imprinted genes so far analyzed showed high expression in the placental tissues including yolk sac. Because there existed a high correlation between high expression in the placental tissues and the imprinted status of the gene questioned, we proposed a novel hypothesis that imprinted genes are regulated to be expressed in the placenta, suggesting the biological significance of the genomic imprinting existed in the formation of placental tissues in mammals.

通过在成人大脑中表达了我们系统地筛选印记基因的系统筛选，这些基因3（PEG3）和5（PEG5）通过我们系统地筛选印迹基因进行了识别。 PEG3编码大型C2H2型锌指蛋白，大概可以发挥新型DNA结合蛋白。 PEG5与神经元蛋白相同，据报道，在第8.5天胚胎和后来在中央神经系统中首先在菱形3和5中表达。使用原位杂交技术，与特定抗体进行免疫染色，我们证明了成人大脑中神经元和神经胶质细胞核的PEG3蛋白。我们还证明了人PEG3基因通过将完整的PEG3 cDNA引入细胞中抑制了神经胶质瘤细胞的肿瘤性。这些结果表明，PEG3蛋白作为DNA结合蛋白，并控制了在细胞周期中起作用的几个基因，因此在神经胶质细胞中充当肿瘤抑制剂。系统分析了印记基因的原位杂交我们已经隔离了表达表明，表达了表达表达早期胚胎中的胶囊分为三组，即中胚层特异性，神经组织特异性，并且在胚胎中表达非常低。然而，到目前为止分析的所有印迹基因均显示在包括蛋黄囊在内的胎盘组织中。由于胎盘组织中的高表达与质疑基因的印迹状态之间存在很高的相关性，因此我们提出了一个新的假设，即在胎盘中调节印记基因被调节，这表明在胎盘中表达了基因组印记的生物学意义哺乳动物中胎盘组织的形成。