Heterochromatinization of the inactive X chromosome and its maintenance mechanism

失活X染色体的异染色质化及其维持机制

• 批准号: 15590288
• 负责人: YOSHIDA Ikuya
• 金额: $ 2.18万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15590288/
• 关键词: mouse; inactive X chromosome; heterochromatin; reactivation; embrvonal carcinoma cells; RNAi; somatic cells; undifferentiated cells; ヒストン修飾; DNAメチル化; 晩期複製; ヒト; ヒストン

In mammalian female somatic cells, one of the two X chromosomes is inactivated and forms heterochromatin. Once established, the inactive X chromosome (Xi) is stably maintained throughout somatic cell divisions, however if Xi introduced into undifferentiated cells, it looses heterochromatic properties and readily reactivated. Certain embryonal carcinoma (EC) cell lines retain Xi, irrespective of its undifferentiated state. We have previously demonstrated that Xi in the MC12 EC cell line is, unlike that in somatic cells, is unstable and reactivated spontaneously. To search genes responsible to this instability of Xi in MC12 EC cells, we screened a series of genes that are expressed exclusively from undifferentiated cells. One of these genes was expressed in a small fraction of the MC12 EC cells, however, ectopic expression of the gene in MC12 increases the frequencies of chromosome-wide reactivation of the inactive X chromosome. Thus, this gene may destabilize facultative heterochromatin of Xi in MC12 EC cells.

在哺乳动物雌性体细胞中，两条X染色体中的一条失活并形成异染色质。一旦建立，失活的X染色体（Xi）在整个体细胞分裂过程中稳定地维持，然而，如果Xi引入未分化的细胞，它就会失去异色特性并容易重新激活。某些胚胎癌（EC）细胞系保留Xi，无论其未分化状态如何。我们之前已经证明，与体细胞不同，MC12 EC细胞系中的Xi是不稳定的，并且是自发重新激活的。为了在MC12 EC细胞中寻找导致Xi不稳定的基因，我们筛选了一系列仅在未分化细胞中表达的基因。其中一个基因在一小部分MC12 EC细胞中表达，然而，MC12中该基因的异位表达增加了无活性X染色体全染色体再激活的频率。因此，该基因可能破坏MC12 EC细胞中Xi的兼性异染色质的稳定性。

项目成果

Kageyama S. et al.: "A novel repeated sequence located on the bovine Y chromosome : Its application to rapid and precise embryo sexing by PCR"Theriogenology. (in press). (2004)

Kageyama S. 等人：“位于牛 Y 染色体上的新型重复序列：其在通过 PCR 进行快速、精确的胚胎性别鉴定中的应用”Theriogenology。

A novel repeated sequence located on the bovine Y chromosome : its application to rapid and precise embryo sexing

位于牛Y染色体上的一个新的重复序列：其在快速和精确的胚胎性别鉴定中的应用

• 发表时间: 2004
• 期刊: J.vet.Med.Sci. 66(5)
• 作者: S.Kageyama

A novel repeated sequence located on the bovine Y chromosome: Its application to rapid and precise embryo sexing by PCR

• DOI: 10.1292/jvms.66.509
• 发表时间: 2004-05-01
• 期刊: JOURNAL OF VETERINARY MEDICAL SCIENCE
• 影响因子: 1.2
• 作者: Kageyama, S;Yoshida, I;Chikuni, K
• 通讯作者: Chikuni, K