X-chromosomes inactivation in cloned mouse embryos
X-chromosomes inactivation in cloned mouse embryos
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DOI：
10.1126/science.290.5496.1578
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发表时间：
2000-11-24
期刊：
影响因子：
56.9
通讯作者：
Jaenisch, R
中科院分区：
文献类型：
--
作者：
Eggan, K;Akutsu, H;Jaenisch, R
为了研究克隆是否重置了体细胞女性核的两条X染色体之间的表观遗传差异，我们监测了克隆小鼠胚胎中的X失活。两条X染色体在克隆胚胎的卵裂过程中都是活跃的，然后在胚胎中随机失活。在滋养外胚层（TE）中，X失活是非随机的，体细胞供体的失活X被选择用于失活。当使用具有两条活性X染色体的女性胚胎干细胞作为供体时，在TE和胚胎中观察到随机X失活。这些结果表明，克隆过程中，表观遗传标记可以在任一X染色体上去除和重建。我们的研究结果还表明，在配子发生过程中施加在X染色体上的表观遗传标记，负责在TE正常的印记X失活，在功能上等同于施加在染色体上的标记体细胞X失活。
To study whether cloning resets the epigenetic differences between the two X chromosomes of a somatic female nucleus, we monitored X inactivation in cloned mouse embryos. Both X chromosomes were active during cleavage of cloned embryos, followed by random X inactivation in the embryo proper. In the trophectoderm (TE), X inactivation was nonrandom with the inactivated X of the somatic donor being chosen for inactivation. When female embryonic stem cells with two active X chromosomes were used as donors, random X inactivation was seen in the TE and embryo. These results demonstrate that epigenetic marks can be removed and reestablished on either X chromosome during cloning. Our results also suggest that the epigenetic marks imposed on the X chromosomes during gametogenesis, responsible for normal imprinted X inactivation in the TE, are functionally equivalent to the marks imposed on the chromosomes during somatic X inactivation.