X chromosome reactivation and regulation in cloned embryos
X chromosome reactivation and regulation in cloned embryos
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DOI：
10.1016/j.ydbio.2005.01.016
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发表时间：
2005-03-15
影响因子：
2.7
通讯作者：
Latham, KE
中科院分区：
文献类型：
--
作者：
Nolen, LD;Gao, SR;Latham, KE
体细胞核移植胚胎表现出广泛的表观遗传异常，包括异常甲基化和异常印迹基因表达。本研究对着床前和着床后的核移植胚胎进行了X染色体失活（XCI）分析。克隆囊胚可能以梯度方式重新激活失活的体细胞X染色体。通过Xist RNA和Eed蛋白定位分析XCI揭示了克隆胚胎内的异质性，一些细胞成功灭活了X染色体，而另一些细胞则失败了。此外，相当比例的细胞含有两条以上的X染色体，这与四倍体的发生率增加有关。通常在着床前胚胎和胚胎外组织中发现的印迹XCI，在后期克隆的囊胚或胎盘中没有观察到，尽管胎儿重现了Xce效应。我们的结论是。尽管SCNT胚胎可以重新激活、计数和灭活X染色体，但它们不能一致地调节XCI。这些结果说明在克隆胚胎中发现的表观遗传变化的异质性。(C) 2005爱思唯尔公司版权所有。
Somatic cell nuclear transfer embryos exhibit extensive epigenetic abnormalities, including aberrant methylation and abnormal imprinted gene expression. In this study, a thorough analysis of X chromosome inactivation (XCI) was performed in both preimplantation and postimplantation nuclear transfer embryos. Cloned blastocysts reactivated the inactive somatic X chromosome, possibly in a gradient fashion. Analysis of XCI by Xist RNA and Eed protein localization revealed heterogeneity within cloned embryos, with Some Cells successfully inactivating an X chromosome and others failing to do so. Additionally, a significant proportion of cells contained more than two X chromosomes, which correlated with an increased incidence of tetraploidy. Imprinted XCI, normally found in preimplantation embryos and extraembryonic tissues, was not observed in blastocysts or placentae from later stage clones, although fetuses recapitulated the Xce effect. We conclude that. although SCNT embryos can reactivate, count, and inactivate X chromosomes, they are not able to regulate XCI consistently. These results illustrate the heterogeneity of epigenetic changes found in cloned embryos. (C) 2005 Elsevier Inc. All rights reserved.