Role of the Xist gene in X chromosome choosing
Role of the Xist gene in X chromosome choosing
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DOI：
10.1016/s0092-8674(00)81133-2
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发表时间：
1998-03-06
期刊：
影响因子：
64.5
通讯作者：
Jaenisch, R
中科院分区：
文献类型：
--
作者：
Marahrens, Y;Loring, J;Jaenisch, R
在雌性哺乳动物中，一种“随机选择”机制决定了两条X染色体中的哪一条将被灭活。据推测，Xist对异染色质化至关重要，因此在选择机制的下游发挥作用。在这里，我们报告说，女性杂合子的Xist基因，其中包括外显子1的一部分，并延伸到外显子5的内部缺失，经历初级非随机失活的野生型X染色体。因此，Xist基因不仅在染色质重塑中起作用，而且还包括X染色体选择所需的元件。与选择是如何发生的流行观点相冲突，通过删除确定的元件在选择机制中起着积极的作用，并迫使人们重新评估X染色体选择是如何发生的。
In female mammals a "random choice" mechanism decides which of the two X chromosomes will be inactivated. It has been postulated that Xist is crucial for heterochromatinization and thus functions downstream of the choice mechanism. Here we report that females heterozygous for an internal deletion in the Xist gene, which includes part of exon 1 and extends to exon 5, undergo primary nonrandom inactivation of the wild-type X chromosome. The Xist gene, therefore, not only has a role in chromatin remodeling, but also includes an element required for X chromosome choosing. In conflict with the prevailing view of how choosing occurs, the element identified by the deletion plays a positive role in the choice mechanism and forces a reassessment of how X chromosome choosing is thought to occur.