Xist/Tsix expression dynamics during mouse peri-implantation development revealed by whole-mount 3D RNA-FISH
Xist/Tsix expression dynamics during mouse peri-implantation development revealed by whole-mount 3D RNA-FISH
复制标题
全贴装 3D RNA-FISH 显示小鼠植入周围发育过程中的 Xist/Tsix 表达动态
DOI：
10.1038/s41598-019-38807-0
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Abe K.
中科院分区：
文献类型：
--
作者：
Shiura H;Abe K.
在小鼠围着床期发育过程中，X染色体失活（XCI）状态发生动态变化。在这里，我们通过使用链特异性探针的整装3D RNA-FISH检测了Xi及其反义配偶体Tsix的表达，并评估了XCI状态。结果表明，Xistr的表达在胚胎4.5天时完全消失，没有Tsix的激活，在一些细胞中，Xistr的表达在胚胎4.75天时出现，这表明在这些细胞中，随机XCI已经开始。有趣的是，在E5.25和E5.5时经常观察到表现出双等位基因Xistexpression的上胚层细胞（~15%）。表观遗传修饰的免疫染色分析表明，表观基因组状态的全球变化伴随着从印记到随机XCI的转变而发生。然而，H3K27me3修饰的整体上调比其他修饰更早开始，特别是在Xisterasure进展期间发生在ICM中。尽管Xistexpression和印迹XCI在原始内胚层/内脏内胚层和滋养外胚层/胚外外外胚层谱系中被认为是稳定的，但Xistclouds的短暂丢失仅在胚外外胚层细胞的一个子集中被注意到，这表明Xistregulation在三个不同的胚胎组织层中具有不同的特征。这些结果将为进一步研究XCI在体内的调节功能奠定基础。
During peri-implantation development in mice, X chromosome inactivation (XCI) status changes dynamically. Here, we examined the expression ofXistand its antisense partner,Tsix, via whole-mount 3D RNA-FISH using strand-specific probes and evaluated XCI status. The results indicate thatXistexpression disappears completely by embryonic day (E) 4.5 withoutTsixactivation in the ICM and thatXistre-expression occurs at E4.75 in some cells, suggesting that random XCI is already initiated in these cells. Intriguingly, epiblast cells exhibiting biallelicXistexpression were observed frequently (~15%) at E5.25 and E5.5. Immunostaining analysis of epigenetic modifications suggests that global change in epigenomic status occurs concomitantly with the transition from imprinted to random XCI. However, global upregulation of H3K27me3 modifications initiated earlier than other modifications, occurring specifically in ICM during progression ofXisterasure. Although bothXistexpression and imprinted XCI are thought to be stable in the primitive endoderm/visceral endoderm and trophectoderm/extraembryonic ectoderm lineages, transient loss ofXistclouds was noted only in a subset of extraembryonic ectodermal cells, suggesting distinct features ofXistregulation among the three different embryonic tissue layers. These results will serve as a basis for future functional studies of XCI regulationin vivo.