Attenuated spread of X-inactivation in an X;autosome translocation
Attenuated spread of X-inactivation in an X;autosome translocation
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DOI：
10.1073/pnas.0602021103
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发表时间：
2006-05-16
影响因子：
11.1
通讯作者：
Nesterova, Tatyana B.
中科院分区：
文献类型：
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作者：
Popova, Bilyana C.;Tada, Takashi;Nesterova, Tatyana B.
雌性哺乳动物中的 X 失活涉及整个染色体的转录沉默，以响应顺式作用非编码 RNA，即 X 失活特异性转录物 (Xist)。 Xist 还可以使常染色体序列失活，例如 X；常染色体易位；但在这里，沉默似乎效率相对较低。这种变异归因于 X 失活开始时 Xist RNA 的扩散减弱或常染色体沉默维持效率低下。迄今为止的证据有利于后者。在这里，我们证明了 T(X;4)37H X;常染色体易位中 X 失活开始时 Xist RNA 的扩散减弱。我们的研究结果提供了直接证据，表明潜在的染色体/染色质特征可以破坏主要失活信号的传播。
X inactivation in female mammals involves transcriptional silencing of an entire chromosome in response to a cis-acting noncoding RNA, the X inactive-specific transcript (Xist). Xist can also inactivate autosomal sequences, for example, in X;autosome translocations; but here, silencing appears to be relatively inefficient. This variation has been attributed to either attenuated spreading of Xist RNA at the onset of X inactivation or inefficient maintenance of autosomal silencing. Evidence to date has favored the latter. Here, we demonstrate attenuated spreading of Xist RNA at the onset of X inactivation in the T(X;4)37H X;autosome translocation. Our findings provide direct evidence that underlying chromosome/chromatin features can disrupt spreading of the primary inactivating signal.