Gene trap as a tool for genome annotation and analysis of X chromosome inactivation in human embryonic stem cells
Gene trap as a tool for genome annotation and analysis of X chromosome inactivation in human embryonic stem cells
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DOI：
10.1093/nar/gkh746
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发表时间：
2004-01-01
影响因子：
14.9
通讯作者：
Benvenisty, N
中科院分区：
文献类型：
--
作者：
Dhara, SK;Benvenisty, N
人类胚胎干细胞（ES细胞）被认为是移植医学中的一种重要工具。然而，它们在人类遗传学中也起着重要作用。利用基因捕获策略，我们创建了一个在人类ES细胞中具有插入突变的克隆库。这些插入发生在已知、预测和未知的基因内，从而帮助我们注释人类基因组中的基因。基因组中的插入发生在多条染色体上，更倾向于较大的染色体。利用一个整合发生在X染色体上的克隆，我们研究了人类细胞中的X染色体失活。因此我们表明，在未分化的女性人类ES细胞中，两条X染色体都保持活性，并且在分化时一条染色体发生失活。在分化的胚胎细胞中，失活是随机的，而在胚外细胞中则是非随机的。此外，利用一种选择方法，我们证明在少数细胞中，即使在未分化细胞中也会发生部分失活和XIST表达。我们认为，与分化同时发生的人类胚胎发生过程中的X染色体失活可能与分化过程是分离的。人类ES细胞的基因操作现在为分析人类的染色体状态和基因表达开辟了新的途径。
Human embryonic stem (ES) cells were suggested to be an important tool in transplantation medicine. However, they also play a major role in human genetics. Using the gene trap strategy, we have created a bank of clones with insertion mutations in human ES cells. These insertions occurred within known, predicted and unknown genes, and thus assist us in annotating the genes in the human genome. The insertions into the genome occurred in multiple chromosomes with a preference to larger chromosomes. Utilizing a clone where the integration occurred in the X chromosome, we have studied X-chromosome inactivation in human cells. We thus show that in undifferentiated female human ES cells both X chromosomes remain active and upon differentiation one chromosome undergoes inactivation. In the differentiated embryonic cells the inactivation is random, while in the extra-embryonic cells it is non-random. In addition, using a selection methodology, we demonstrate that in a minority of the cells partial inactivation and XIST expression occur even in the undifferentiated cells. We suggest that X chromosome inactivation during human embryogenesis, which coincides with differentiation, may be separated from the differentiation process. The genetic manipulation of human ES cells now opens new ways of analyzing chromosome status and gene expression in humans.